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1

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941 OTS

2

Assessment of Research Quality Utrecht institute of Linguistics OTS (UiL OTS)  

E-Print Network [OSTI]

Assessment of Research Quality Utrecht institute of Linguistics OTS (UiL OTS) Faculty of Arts and the Humanities / Arts Utrecht University 1997 - 2004 October 2005 #12;Title: Assessment of Research Quality Utrecht institute of Linguistics OTS (UiL OTS) Faculty of Arts and the Humanities / Arts Utrecht

Utrecht, Universiteit

3

A Rob otLaboratoryforTeachingArtiflcialIntelligence / Deepak Kumar  

E-Print Network [OSTI]

A Rob otLaboratoryforTeachingArtiflcialIntelligence / Deepak Kumar Department ofMathematics Bryn Ma tasks.Inthelaboratory,studentsbuildtheirown robots and programthem toaccomplishthetasks.By con thestudyofAI centersaroundhow besttoimplement thismappingfromperceptionstoactions.The robot perspective

Kumar, Deepak

4

OmniTread OT-4 Serpentine Robot new Features and Experiments Johann Borenstein* and Malik Hansen  

E-Print Network [OSTI]

1 OmniTread OT-4 Serpentine Robot ­ new Features and Experiments Johann Borenstein* and Malik-of-freedom joints. The OT-4 can climb over obstacles that are much higher than the robot itself, propel itself of the OT-4. Keywords: OmniTread, Serpentine Robot, Snake Robot, Snakebot, Mobile Robot, Hyper

Borenstein, Johann

5

The OmniTread OT-4 Serpentine Robot1 Design and Performance  

E-Print Network [OSTI]

The OmniTread OT-4 Serpentine Robot1 ­ Design and Performance Johann Borenstein*, Malik Hansen joints. The OT-4 can climb over obstacles that are much higher than the robot itself, propel itself@umich.edu, hansenm@umich.edu, aborrell@umich.edu ABSTRACT Serpentine robots are slender, multi-segmented vehicles

Borenstein, Johann

6

Abstract --Recent human pharmacological fMRI studies suggest that oxytocin (OT) is a centrally-acting  

E-Print Network [OSTI]

Abstract -- Recent human pharmacological fMRI studies suggest that oxytocin (OT) is a centrally-acting neurotransmitter important in the development and expression of trusting relationships in men and women. OT of several key interacting brain regions affected by OT neurophysiology during social trust behavior

Dascalu, Sergiu

7

E-Print Network 3.0 - arvo ots tnu Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

) + 2EK(w, ) + O(t3 ) , as t 0, where wn and wnn denote the rst and second Source: Frey, Pascal - Laboratoire Jacques-Louis Lions, Universit Pierre-et-Marie-Curie, Paris 6...

8

Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle, Alexander Romanovsky  

E-Print Network [OSTI]

Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle-The-Shelf) item. The case study used a Simulink model of a steam boiler system together with an OTS PID in practice, employing software models of the PID controller and the steam boiler system rather than

Newcastle upon Tyne, University of

9

Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle, Alexander Romanovsky  

E-Print Network [OSTI]

1 Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle employing an OTS (Off-The-Shelf) item. The case study used a Simulink model of a steam boiler system, employing software models of the PID controller and the steam boiler system rather than conducting

Newcastle upon Tyne, University of

10

The OmniTread OT-4 Serpentine Robot for Emergencies and Hazardous Environments  

E-Print Network [OSTI]

The OmniTread OT-4 Serpentine Robot for Emergencies and Hazardous Environments Johann Borenstein: johannb@umich.edu, hansenm@umich.edu, hunguyen@umich.edu Abstract ­ Serpentine robots are slender, multi- segmented vehicles designed to provide greater mobility than conventional wheeled or tracked robots

Borenstein, Johann

11

Abstract--This paper describes the development and testing of control of the OmniTread OT-4 robot by the Seventh  

E-Print Network [OSTI]

Abstract--This paper describes the development and testing of control of the OmniTread OT-4 robot system developed in simulation was tested by controlling the real OT-4 robot in the laboratory. The performance of the real OT-4 robot under 7G control on stairs, parallel bars, a slalom course, and stairs

Borenstein, Johann

12

University/Classified Non-Exempt OT Compensation The College of William and Mary/VIMS Banner ID # : Date  

E-Print Network [OSTI]

University/Classified Non-Exempt OT Compensation The College of William and Mary/VIMS Employer: W&M VIMS Banner ID # : Date: Employee Name: Last First Middle University/Classified Non-Exempt Overtime

Swaddle, John

13

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545*.MSE Cores" _August 4, 1992 TO:

14

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander Williams

15

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander

16

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941

17

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@

18

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@* pp4 r

19

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@* pp4

20

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@*

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

OTS NOTE  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@*2,

22

OTS NOTF  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@*2,

23

OT SPECIFIED I OTHER AMENDMENT OF SOLICITATI ON/MODIFICATION OF CONTRACT  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the ContributionsArmsSpeedingSpeeding accessand Technical Information TimOT SPECIFIED

24

Solar energy system performance evaluation - final report for Honeywell OTS 45, Salt River Project, Phoenix, Arizona  

SciTech Connect (OSTI)

This report describes the operation and technical performance of the Solar Operational Test Site (OTS 45) at Salt River Project in Phoenix, Arizona, based on the analysis of data collected between April 1981 and March 31, 1982. The following topics are discussed: system description, performance assessment, operating energy, energy savings, system maintenance, and conclusions. The solar energy system at OTS 45 is a hydronic heating and cooling system consisting of 8208 square feet of liquid-cooled flat-plate collectors; a 2500-gallon thermal storage tank; two 25-ton capacity organic Rankine-cycle-engine-assisted water chillers; a forced-draft cooling tower; and associated piping, pumps, valves, controls and heat rejection equipment. The solar system has eight basic modes of operation and several combination modes. The system operation is controlled automatically by a Honeywell-designed microprocessor-based control system, which also provides diagnostics. Based on the instrumented test data monitored and collected during the 8 months of the Operational Test Period, the solar system collected 1143 MMBtu of thermal energy of the total incident solar energy of 3440 MMBtu and provided 241 MMBtu for cooling and 64 MMBtu for heating. The projected net annual electrical energy savings due to the solar system was approximately 40,000 kWh(e).

Mathur, A K

1983-09-01T23:59:59.000Z

25

Solar energy system performance evaluation: final report for Honeywell OTS 41, Shenandoah (Newnan), Georgia  

SciTech Connect (OSTI)

The operation and technical performance of the Solar Operational Test Site (OTS 41) located at Shenandoah, Georgia, are described, based on the analysis of data collected between January and August 1981. The following topics are discussed: system description, performance assessment, operating energy, energy savings, system maintenance, and conclusions. The solar energy system at OTS 41 is a hydronic heating and cooling system consisting of 702 square feet of liquid-cooled flat-plate collectors; a 1000-gallon thermal storage tank; a 3-ton capacity organic Rankine-cycle-engine-assisted air conditioner; a water-to-air heat exchanger for solar space heating; a finned-tube coil immersed in the storage tank to preheat water for a gas-fired hot water heater; and associated piping, pumps, valves, and controls. The solar system has six basic modes of operation and several combination modes. The system operation is controlled automatically by a Honeywell-designed microprocessor-based control system, which also provides diagnostics. Based on the instrumented test data monitored and collected during the 7 months of the Operational Test Period, the solar system collected 53 MMBtu of thermal energy of the total incident solar energy of 219 MMBtu and provided 11.4 MMBtu for cooling, 8.6 MMBtu for heating, and 8.1 MMBtu for domestic hot water. The projected net annual energy savings due to the solar system were approximately 50 MMBtu of fossil energy (49,300 cubic feet of natural gas) and a loss of 280 kWh(e) of electrical energy.

Mathur, A K; Pederson, S

1982-08-01T23:59:59.000Z

26

AVESTAR Center for operational excellence of clean energy plants and DYNSIM OTS / EyeSim ITS integration  

SciTech Connect (OSTI)

This Power-Point presentation with notes starts with a brief overview of US energy challenging, particularly as regards power generation capacity and clean energy plant operations. It then goes on to present Advanced Virtual Energy Simulation Training And Research (AVESTAR{trademark}) beginning with a statement of its missions and goals, then moves to the subject of Integrated Gasification Combined Cycle (IGCC) with CO{sub 2} Capture, first providing a brief overview of the process, then moving on to Dynamic Simulator/Operator Training System (OTS) and 3D Virtual Immersive Training System (ITS). The presentation continues to describe AVESTAR center facilities, locations, and training systems and to look at future directions for virtual energy simulation.

Provost, G.

2012-01-01T23:59:59.000Z

27

DUSTY EXPLOSIONS FROM DUSTY PROGENITORS: THE PHYSICS OF SN 2008S AND THE 2008 NGC 300-OT  

SciTech Connect (OSTI)

SN 2008S and the 2008 NGC 300-OT were explosive transients of stars self-obscured by very dense, dusty stellar winds. An explosive transient with an unobserved shock breakout luminosity of order 10{sup 10} L{sub sun} is required to render the transients little obscured and visible in the optical at their peaks. Such a large breakout luminosity then implies that the progenitor stars were cool, red supergiants, most probably {approx}9 M{sub sun} extreme asymptotic giant branch stars. As the shocks generated by the explosions propagate outward through the dense wind, they produce a shock luminosity in soft X-rays that powers the long-lived luminosity of the transients. Unlike typical cases of transients exploding into a surrounding circumstellar medium, the progenitor winds in these systems are optically thick to soft X-rays, easily absorb radio emission, and rapidly reform dust destroyed by the peak luminosity of the transients. As a result, X-rays are absorbed by the gas and the energy is ultimately radiated by the reformed dust. Three years post-peak, both systems are still significantly more luminous than their progenitor stars, but they are again fully shrouded by the reformed dust and only visible in the mid-IR. The high luminosity and heavy obscuration may make it difficult to determine the survival of the progenitor stars for {approx}10 years. However, our model indicates that SN 2008S, but not the NGC 300-OT, should now be a detectable X-ray source. SN 2008S has a higher estimated shock velocity and a lower density wind, so the X-rays begin to escape at a much earlier phase.

Kochanek, C. S. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus OH 43210 (United States)

2011-11-01T23:59:59.000Z

28

THE DIVERSITY OF MASSIVE STAR OUTBURSTS. I. OBSERVATIONS OF SN2009ip, UGC 2773 OT2009-1, AND THEIR PROGENITORS  

SciTech Connect (OSTI)

Despite both being outbursts of luminous blue variables (LBVs), SN 2009ip and UGC 2773 OT2009-1 have very different progenitors, spectra, circumstellar environments, and possibly physical mechanisms that generated the outbursts. From pre-eruption Hubble Space Telescope images, we determine that SN 2009ip and UGC 2773 OT2009-1 have initial masses of {approx}> 60 and {approx}> 25 M{sub sun}, respectively. Optical spectroscopy shows that at peak, SN 2009ip had a 10,000 K photosphere and its spectrum was dominated by narrow H Balmer emission, similar to classical LBV giant outbursts, also known as 'supernova impostors'. The spectra of UGC 2773 OT2009-1, which also have narrow H{alpha} emission, are dominated by a forest of absorption lines, similar to an F-type supergiant. Blueshifted absorption lines corresponding to ejecta at a velocity of 2000-7000 km s{sup -1} are present in later spectra of SN 2009ip-an unprecedented observation for LBV outbursts, indicating that the event was the result of a supersonic explosion rather than a subsonic outburst. The velocity of the absorption lines increases between two epochs, suggesting that there were two explosions in rapid succession. A rapid fading and rebrightening event concurrent with the onset of the high-velocity absorption lines is consistent with the double-explosion model. A near-infrared excess is present in the spectra and photometry of UGC 2773 OT2009-1 that is consistent with {approx}2100 K dust emission. We compare the properties of these two events and place them in the context of other known massive star outbursts such as {eta} Car, NGC 300 OT2008-1, and SN 2008S. This qualitative analysis suggests that massive star outbursts have many physical differences that can manifest as the different observables seen in these two interesting objects.

Foley, Ryan J.; Berger, Edo; Challis, Peter J.; Soderberg, Alicia M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fox, Ori [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Levesque, Emily M. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI 96822 (United States); Ivans, Inese I. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Rhoads, James E., E-mail: rfoley@cfa.harvard.edu [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States)

2011-05-01T23:59:59.000Z

29

PRECEDING F!_GE E_LA."jK _OT F:LP#,ED THE ROLES OF HUMANS AND ROBOTS AS  

E-Print Network [OSTI]

307 PRECEDING F!_GE E_LA."jK _OT F:LP#,ED THE ROLES OF HUMANS AND ROBOTS AS FIELD GEOLOGISTS field study on the Moon is through the use of teleoperated robots, under the da'rect control of a human geologist who remains at the lunar base, or poss_ly on Earth. These robots umuld hate a global traverse

Spudis, Paul D.

30

Optical properties of ZnO/ZnS and ZnO/ZnTe heterostructures for photovoltaic applications  

E-Print Network [OSTI]

ZnTe heterostructures for photovoltaic applications Joshuatoo large for optimal photovoltaic e?ciency. By using band-nanowires can be used as photovoltaic devices with organic

Schrier, Joshua; Demchenko, Denis O.; Wang, Lin-Wang; Alivisatos, A. Paul

2008-01-01T23:59:59.000Z

31

ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . Abstract: Band...

32

Structural and magnetic properties of NiZn and Zn ferrite thin films obtained by laser ablation deposition  

E-Print Network [OSTI]

Structural and magnetic properties of NiZn and Zn ferrite thin films obtained by laser ablation ferrite structures. Our investigations were performed on NiZn and Zn ferrite films deposited on silicon of the blocking temperature in both NiZn and Zn ferrite systems. © 2005 American Institute of Physics. DOI: 10

McHenry, Michael E.

33

Ultraviolet emission from a multi-layer graphene/MgZnO/ZnO light-emitting diode  

SciTech Connect (OSTI)

We report on ultraviolet emission from a multi-layer graphene (MLG)/MgZnO/ZnO light-emitting diodes (LED). The p-type MLG and MgZnO in the MLG/MgZnO/ZnO LED are used as transparent hole injection and electron blocking layers, respectively. The current-voltage characteristics of the MLG/MgZnO/ZnO LED show that current transport is dominated by tunneling processes in the MgZnO barrier layer under forward bias conditions. The holes injected from p-type MLG recombine efficiently with the electrons accumulated in ZnO, and the MLG/MgZnO/ZnO LED shows strong ultraviolet emission from the band edge of ZnO and weak red-orange emission from the deep levels of ZnO.

Kang, Jang-Won; Choi, Yong-Seok; Goo Kang, Chang; Hun Lee, Byoung [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Byeong-Hyeok [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Tu, C. W. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093-0407 (United States); Park, Seong-Ju, E-mail: sjpark@gist.ac.kr [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

2014-02-03T23:59:59.000Z

34

ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells  

DOE Patents [OSTI]

The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

Bhattacharya, Raghu N. (Littleton, CO)

2009-11-03T23:59:59.000Z

35

891070-9932/142014IEEE sEptEmbEr 2014 IEEE rObOtICs & AUtOmAtION mAGAZINE By Yaroslav Tenzer, Leif P. Jentoft, and Robert D. Howe  

E-Print Network [OSTI]

891070-9932/14©2014IEEE sEptEmbEr 2014 · IEEE rObOtICs & AUtOmAtION mAGAZINE · The Feel of MEMS available for a wide range of robotics and human-interface applications. Background Tactile sensing, such as the location of object contacts on the robot hand and contact pressure distribution, are believed

36

OTS NOTE DATE: TO: FROM:  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCT 28 1% - :NEW; c3 Alexander941@*2, TO:

37

An electrostatic nanogenerator based on ZnO/ZnS core/shell electrets with stabilized quasi-permanent charge  

SciTech Connect (OSTI)

ZnO-based nanogenerators with excellent performance and convenient functionalization are particularly desirable for self-powered technology, which is however difficult to achieve simultaneously in traditional piezoelectric ZnO nanogenerators. Here, we report a design of electrostatic ZnO nanogenerator by virtue of a type-II ZnO/ZnS core/shell nanostructure electrets, which can turn acoustic waves into electric power with an energy conversion efficiency of 2.2%. The ZnO/ZnS core/shell electrets are charged by ultraviolet irradiation with a long-term stability of the electrostatic charges under ambient condition. The electronic and atomic structure evolution in the charged ZnO/ZnS core/shell electrets are also discussed by detailed experimental and theoretical investigations. This design opens up an alternative path for fabricating robust ZnO-based nanogenerator for future nanotechnology application.

Wang, Chao; Cai, Liang; Feng, Yajuan; Chen, Lin; Yan, Wensheng, E-mail: ywsh2000@ustc.edu.cn, E-mail: zhsun@ustc.edu.cn; Liu, Qinghua; Yao, Tao; Hu, Fengchun; Pan, Zhiyun; Sun, Zhihu, E-mail: ywsh2000@ustc.edu.cn, E-mail: zhsun@ustc.edu.cn; Wei, Shiqiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China)

2014-06-16T23:59:59.000Z

38

Novel Stabilization Mechanism on Polar Surfaces: ZnO(0001)-Zn Olga Dulub,1  

E-Print Network [OSTI]

r Materialphysik and Centre for Computational Materials Science, Universitat Wien, A-1090 Wien, Austria (Received identification of the stabilization mechanisms of polar ZnO surfaces and the resulting surface properties would will cancel the polarity. If the Zn-terminated surface is less positive and the O-terminated surface layer

Diebold, Ulrike

39

Cyclotron production of {sup 61}Cu using natural Zn and enriched {sup 64}Zn targets  

SciTech Connect (OSTI)

Copper-61 ({sup 61}Cu) shares with {sup 64}Cu certain advantages for PET diagnostic imaging, but has a shorter half-life (3.4hr vs. 12.7hr) and a greater probability of positron production per disintegration (61% vs. 17.9%). One important application is for in vivo imaging of hypoxic tissue. In this study {sup 61}Cu was produced using the {sup 64}Zn(p,{alpha}){sup 61}Cu reaction on natural Zn or enriched {sup 64}Zn targets. The enriched {sup 64}Zn (99.82%) was electroplated onto high purity gold or silver foils or onto thin Al discs. A typical target bombardment used 30{mu}A; at 11.7, 14.5 or 17.6MeV over 30-60min. The {sup 61}Cu (radiochemical purity of >95%) was separated using a combination of cation and anion exchange columns. The {sup 64}Zn target material was recovered after each run, for re-use. In a direct comparison with enriched {sup 64}Zn-target results, {sup 61}Cu production using the cheaper {sup nat}Zn target proved to be an effective alternative.

Asad, A. H.; Smith, S. V.; Chan, S.; Jeffery, C. M.; Morandeau, L.; Price, R. I. [RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia, Imaging and Applied Physics, Curtin University, Perth, Australia, and Center of Excellence in Anti-matter Matter Studies, Australian National University, Can (Australia); Brookhaven National Laboratory, Upton, NY (United States) and Center of Excellence in Anti-matter Matter Studies, Australian National University, Canberra (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); Center of Excellence in Anti-matter Matter Studies, Australian National University, Canberra, Australia, and Chemistry, University of Western Australia, Pe (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia and Physics, University of Western Australia, Perth (Australia)

2012-12-19T23:59:59.000Z

40

Acceptors in ZnO nanocrystals  

SciTech Connect (OSTI)

Zinc oxide (ZnO) has potential for a range of optoelectronic applications. In this work, we studied the defect properties of ZnO nanocrystals, grown by a solid-state pyrolytic reaction method, using IR and electron paramagnetic resonance (EPR) spectroscopy. A series of IR absorption peaks have been observed at liquid-helium temperatures. These transition lines suggest a hydrogenic acceptor with a hole binding energy of ~ 0.4 - 0.5 eV. EPR measurements in the dark showed the well-known donor line at g = 1.96, and a line at g = 2.003, which we attribute to acceptors that involve a zinc vacancy. A line at g = 2.013, only seen after exposure to light, is assigned to nonaxial zinc vacancy-hydrogen complexes. Given the current lack of suitable acceptor dopants in ZnO, vacancy complexes may provide the best route toward p-type conductivity.

Teklemichael, Samuel T.; Oo, W.M.H.; Matthew, McClusky; Walter, Eric D.; Hoyt, David W.

2011-06-09T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

DOI : 10. 1051/jp4 :20030389 Zn speciation in  

E-Print Network [OSTI]

smelter in Northem France ( [Zn] = 6600 and as a 40 cm thick layer on a agricultural soil in 1997. zen

42

Formation of Zn-rich phyllosilicate, Zn-layered double hydroxide and hydrozincite in contaminated calcareous soils  

E-Print Network [OSTI]

Zn/Al hydrotalcite in smelter-impacted soils from northernQuantitative Zn speciation in smelter-contaminated soils byand bioavailability of zinc in a smelter contaminated soil.

Jacquat, Olivier

2009-01-01T23:59:59.000Z

43

Electroluminescence of ZnO-based semiconductor heterostructures  

SciTech Connect (OSTI)

Using pulsed laser deposition, we have grown n-ZnO/p-GaN, n-ZnO/i-ZnO/p-GaN and n-ZnO/n-Mg{sub 0.2}Zn{sub 0.8}O/i-Cd{sub 0.2}Zn{sub 0.8}O/p-GaN light-emitting diode (LED) heterostructures with peak emission wavelengths of 495, 382 and 465 nm and threshold current densities (used in electroluminescence measurements) of 1.35, 2, and 0.48 A cm{sup -2}, respectively. Because of the spatial carrier confinement, the n-ZnO/n-Mg{sub 0.2}Zn{sub 0.8}O/i-Cd{sub 0.2}Zn{sub 0.8}O/p-GaN double heterostructure LED offers a higher electroluminescence intensity and lower electroluminescence threshold in comparison with the n-ZnO/p-GaN and n-ZnO/i-ZnO/p-GaN LEDs. (lasers)

Novodvorskii, O A; Lotin, A A; Panchenko, Vladislav Ya; Parshina, L S; Khaidukov, E V; Zuev, D A; Khramova, O D [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)

2011-01-31T23:59:59.000Z

44

Twinning effect on photoluminescence spectra of ZnSe nanowires  

SciTech Connect (OSTI)

Bandgap engineering in a single material along the axial length of nanowires may be realized by arranging periodic twinning, whose twin plane is vertical to the axial length of nanowires. In this paper, we report the effect of twin on photoluminescence of ZnSe nanowires, which refers to the bandgap of it. The exciton-related emission peaks of transverse twinning ZnSe nanowires manifest a 10-meV-blue-shift in comparison with those of longitudinal twinning ZnSe nanowires. The blue-shift is attributed to quantum confinement effect, which is influenced severely by the proportion of wurtzite ZnSe layers in ZnSe nanowires.

Xu, Jing; Wang, Chunrui, E-mail: crwang@dhu.edu.cn; Wu, Binhe; Xu, Xiaofeng [Department of Applied Physics and State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 Renmin Rd. North, Songjiang District, Shanghai 201620 (China); Chen, Xiaoshuang [Department of Applied Physics and State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 Renmin Rd. North, Songjiang District, Shanghai 201620 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 200083 (China); Oh, Hongseok; Baek, Hyeonjun; Yi, Gyu-Chul [Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-747 (Korea, Republic of)

2014-11-07T23:59:59.000Z

45

Green emission in carbon doped ZnO films  

SciTech Connect (OSTI)

The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR) and low temperature photoluminescence (PL) measurement.

Tseng, L. T.; Yi, J. B., E-mail: jiabao.yi@unsw.edu.au; Zhang, X. Y.; Xing, G. Z.; Luo, X.; Li, S. [School of Materials Science and Engineering, University of New South Wales, Kensington, NSW, 2052 (Australia); Fan, H. M. [School of Chemical Engineering, Northwest University, Xi'an 710069 (China); Herng, T. S.; Ding, J. [Department of Materials Science and Engineering, National University of Singapore, 119260 (Singapore); Ionescu, M. [Australian Nuclear Science and Technology Organization, (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234 (Australia)

2014-06-15T23:59:59.000Z

46

Thermoelectric properties of ZnSb films grown by MOCVD  

SciTech Connect (OSTI)

The thermoelectric properties of ZnSb films grown by metallorganic chemical vapor deposition (MOCVD) are reported. The growth conditions necessary to obtain stoichiometric ZnSb films and the effects of various growth parameters on the electrical conductivity and Seebeck coefficients of the films are described. The as-grown ZnSb films are p-type. It was observed that the thicker ZnSb films offer improved carrier mobilities and lower free-carrier concentration levels. The Seebeck coefficient of ZnSb films was found to rise rapidly at approximately 160 C. The thicker films, due to the lower doping levels, indicate higher Seebeck coefficients between 25 to 200 C. A short annealing of the ZnSb film at temperatures of {approximately}200 C results in reduced free-carrier level. Thermal conductivity measurements of ZnSb films using the 3-{omega} method are also presented.

Venkatasubramanian, R.; Watko, E.; Colpitts, T.

1997-07-01T23:59:59.000Z

47

Study of stability of ZnO nanoparticles and growth mechanisms of colloidal ZnO nanorods  

E-Print Network [OSTI]

changes. Furthermore, upon annealing, the white precipitate is recovered to wurtize ZnO. XRD and TEM are used to study the structural transformation of ZnO nanoparticles. v Using the zinc oxide spherical colloidal solution, ZnO nanorods could..., such as Si, GaAs and CdS. The applications of ZnO to the UV-emitting diodes, cathode-ray phosphors, transparent conductor, varistors, chemical sensors, UV-protection films, and ultrafast nonlinear optical devices have been performed [8]. To prepare Zn...

Lee, Kwang Jik

2006-10-30T23:59:59.000Z

48

Defect induced ferromagnetism in undoped ZnO nanoparticles  

SciTech Connect (OSTI)

Undoped ZnO nanoparticles (NPs) with size ?12?nm were produced using forced hydrolysis methods using diethylene glycol (DEG) [called ZnO-I] or denatured ethanol [called ZnO-II] as the reaction solvent; both using Zn acetate dehydrate as precursor. Both samples showed weak ferromagnetic behavior at 300?K with saturation magnetization M{sub s}?=?0.077 0.002 memu/g and 0.088 0.013 memu/g for ZnO-I and ZnO-II samples, respectively. Fourier transform infrared (FTIR) spectra showed that ZnO-I nanocrystals had DEG fragments linked to their surface. Photoluminescence (PL) data showed a broad emission near 500?nm for ZnO-II which is absent in the ZnO-I samples, presumably due to the blocking of surface traps by the capping molecules. Intentional oxygen vacancies created in the ZnO-I NPs by annealing at 450?C in flowing Ar gas gradually increased M{sub s} up to 90?min and x-ray photoelectron spectra (XPS) suggested that oxygen vacancies may have a key role in the observed changes in M{sub s}. Finally, PL spectra of ZnO showed the appearance of a blue/violet emission, attributed to Zn interstitials, whose intensity changes with annealing time, similar to the trend seen for M{sub s}. The observed variation in the magnetization of ZnO NP with increasing Ar annealing time seems to depend on the changes in the number of Zn interstitials and oxygen vacancies.

Rainey, K.; Chess, J.; Eixenberger, J.; Tenne, D. A.; Hanna, C. B.; Punnoose, A., E-mail: apunnoos@boisestate.edu [Department of Physics, Boise State University, Boise, Idaho 83725 (United States)

2014-05-07T23:59:59.000Z

49

Spin noise spectroscopy of ZnO  

SciTech Connect (OSTI)

We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

Horn, H.; Berski, F.; Hbner, J.; Oestreich, M. [Institute for Solid State Physics, Leibniz Universitt Hannover, Appelstr. 2, 30167 Hannover (Germany); Balocchi, A.; Marie, X. [INSA-CNRS-UPS, LPCNO, Universit de Toulouse, 135 Av. de Rangueil, 31077 Toulouse (France); Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A. [Institute of Semiconductor Technology, Technische Universitt Braunschweig, Hans-Sommer-Strae 66, 38106 Braunschweig (Germany)

2013-12-04T23:59:59.000Z

50

Compared Raman study of the phase transitions in K2ZnCl4 and Rb2ZnCl4, Rb2ZnBr4, K2SeO4  

E-Print Network [OSTI]

787 Compared Raman study of the phase transitions in K2ZnCl4 and Rb2ZnCl4, Rb2ZnBr4, K2SeO4 M to the incommensurate phase is discussed for the four compounds K2SeO4, K2ZnCl4, Rb2ZnCl4 and Rb2ZnBr4 on the basis measurements on K2ZnC'4 known to exhibit successive phase transitions similar to those of K2SeO4

Paris-Sud XI, Universit de

51

Strong circular photogalvanic effect in ZnO epitaxial films  

SciTech Connect (OSTI)

A strong circular photogalvanic effect (CPGE) in ZnO epitaxial films was reported under interband excitation. It was observed that CPGE current is as large as 100 nA/W in ZnO, which is about one order in magnitude higher than that in InN film while the CPGE currents in GaN films are not detectable. The possible reasons for the above observations are the strong spin orbit coupling in ZnO or the inversed valence band structure of ZnO.

Zhang, Q.; Wang, X. Q.; Yin, C. M.; Shen, B. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Chen, Y. H.; Chang, K. [Laboratory of Semiconductor Materials Science, Institute of Semiconductors, CAS, Beijing 100083 (China); Ge, W. K. [Department of Physics, Tsinghua University, Beijing 100871 (China)

2011-12-23T23:59:59.000Z

52

Built-in electric field in ZnO based semipolar quantum wells grown on (1012) ZnO substrates  

SciTech Connect (OSTI)

We report on the properties of semipolar (Zn,Mg)O/ZnO quantum wells homoepitaxially grown by molecular beam epitaxy on (1012) R-plane ZnO substrates. We demonstrate that atomically flat interfaces can be achieved with fully relaxed quantum wells because the mismatch between (Zn,Mg)O and ZnO is minimal for this growth orientation. The photoluminescence properties evidence a quantum confined Stark effect with an internal electric field estimated to 430 kV/cm for a 17% Mg content in the barriers. The quantum well emission is strongly polarized along the 1210 direction and a comparison with the semipolar bulk ZnO luminescence polarization points to the effect of the confinement.

Chauveau, J.-M.; Xia, Y.; Roland, B.; Vinter, B. [Centre de Recherche sur l'Htro-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France) [Centre de Recherche sur l'Htro-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); University of Nice Sophia Antipolis, Parc Valrose, F-06102 Nice Cedex 2 (France); Ben Taazaet-Belgacem, I.; Teisseire, M.; Nemoz, M.; Brault, J.; Damilano, B.; Leroux, M. [Centre de Recherche sur l'Htro-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France)] [Centre de Recherche sur l'Htro-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France)

2013-12-23T23:59:59.000Z

53

Formation of Zn-rich phyllosilicate, Zn-layered double hydroxide and hydrozincite in contaminated calcareous soils  

E-Print Network [OSTI]

soil thin section and corresponding -XRF maps (black: lowestsection and corresponding - XRF maps for Zn, Ca, Fe and Mn (soil thin section and corresponding -XRF maps (black: lowest

Jacquat, Olivier

2009-01-01T23:59:59.000Z

54

E-Print Network 3.0 - applied zn fe Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

on bulk samples indicated that ZnS and Zn-Fe (oxyhydr) oxides amounted... in the sediment, and from their further oxidative dissolution and ... Source: Lawrence Berkeley...

55

Optical/electrical correlations in ZnO: the plasmonic resonance...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Opticalelectrical correlations in ZnO: the plasmonic resonance phase diagram. Opticalelectrical correlations in ZnO: the plasmonic resonance phase diagram. Abstract: Following...

56

Organic Molecule Functionalized Zn3P2 Nanowire Inorganic-Organic...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Organic Molecule Functionalized Zn3P2 Nanowire Inorganic-Organic Hybrid Thermoelectrics Organic Molecule Functionalized Zn3P2 Nanowire Inorganic-Organic Hybrid Thermoelectrics...

57

E-Print Network 3.0 - av zn cu Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and speciation in Arabidopsis halleri Arabidopsis lyrata progenies presenting Summary: ), copper (Cu) and Zn. Figure 7 compares the distribution of Zn, Mn and Ca in mature leaves...

58

Benefits of homoepitaxy on the properties of nonpolar (Zn,Mg)O/ZnO quantum wells on a-plane ZnO substrates  

SciTech Connect (OSTI)

We report on the properties of nonpolar (Zn,Mg)O/ZnO quantum wells (QW) homoepitaxially grown by molecular beam epitaxy on a-plane ZnO substrates. We demonstrate a drastic improvement of the structural properties. We compare the photoluminescence properties of nonpolar homoepitaxial QWs and nonpolar heteroepitaxial QWs grown on sapphire and show that the reduction in structural defects and the improvement of surface morphology are correlated with a strong enhancement of the photoluminescence properties: reduction in full width at half maximum, strong increase in the luminescence intensities and their thermal stability. The comparison convincingly demonstrates the interest of homoepitaxial nonpolar QWs for bright UV emission applications.

Chauveau, J.-M.; Vinter, B. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications (CRHEA), Centre National de la Recherche Scientifique (CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); University of Nice Sophia Antipolis, Parc Valrose, F-06102 Nice Cedex 2 (France); Teisseire, M.; Kim-Chauveau, H.; Deparis, C.; Morhain, C. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications (CRHEA), Centre National de la Recherche Scientifique (CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France)

2010-08-23T23:59:59.000Z

59

Neutral nitrogen acceptors in ZnO: The {sup 67}Zn hyperfine interactions  

SciTech Connect (OSTI)

Electron paramagnetic resonance (EPR) is used to characterize the {sup 67}Zn hyperfine interactions associated with neutral nitrogen acceptors in zinc oxide. Data are obtained from an n-type bulk crystal grown by the seeded chemical vapor transport method. Singly ionized nitrogen acceptors (N{sup ?}) initially present in the crystal are converted to their paramagnetic neutral charge state (N{sup 0}) during exposure at low temperature to 442 or 633?nm laser light. The EPR signals from these N{sup 0} acceptors are best observed near 5?K. Nitrogen substitutes for oxygen ions and has four nearest-neighbor cations. The zinc ion along the [0001] direction is referred to as an axial neighbor and the three equivalent zinc ions in the basal plane are referred to as nonaxial neighbors. For axial neighbors, the {sup 67}Zn hyperfine parameters are A{sub ?}?=?37.0?MHz and A{sub ?}?=?8.4?MHz with the unique direction being [0001]. For nonaxial neighbors, the {sup 67}Zn parameters are A{sub 1}?=?14.5?MHz, A{sub 2}?=?18.3?MHz, and A{sub 3}?=?20.5?MHz with A{sub 3} along a [101{sup }0] direction (i.e., in the basal plane toward the nitrogen) and A{sub 2} along the [0001] direction. These {sup 67}Zn results and the related {sup 14}N hyperfine parameters provide information about the distribution of unpaired spin density at substitutional neutral nitrogen acceptors in ZnO.

Golden, E. M.; Giles, N. C., E-mail: Nancy.Giles@afit.edu [Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio 45433 (United States); Evans, S. M.; Halliburton, L. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2014-03-14T23:59:59.000Z

60

Fluorescent Sensors for Zn2+ Based on a Fluorescein Platform  

E-Print Network [OSTI]

Fluorescent Sensors for Zn2+ Based on a Fluorescein Platform: Synthesis, Properties fluorescent sensors for Zn2+ that utilize fluorescein as a reporting group, Zinpyr-1 and Zinpyr-2, have been. Both Zinpyr sensors have excitation and emission wavelengths in the visible range (500 nm

Tsien, Roger Y.

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Aerogel tempelated ZnO dye-sensitized solar cells.  

SciTech Connect (OSTI)

Atomic layer deposition is employed to conformally coat low density, high surface area aerogel films with ZnO. The ZnO/aerogel membranes are incorporated as photoanodes in dye-sensitized solar cells, which exhibit excellent power efficiencies of up to 2.4% under 100 mW cm{sup -2} light intensity.

Hamann, T. W.; Martinson , A. B. E.; Elam, J. W.; Pellin, M. J.; Hupp, J. T.; Materials Science Division; Northwestern Univ.

2008-01-01T23:59:59.000Z

62

SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} - two new Ae-Zn-Sn polar intermetallic compounds (Ae: alkaline earth metal)  

SciTech Connect (OSTI)

SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}, two closely related new polar intermetallic compounds, were obtained by high temperature reactions of the elements. Their crystal structures were determined with single crystal XRD methods, and their electronic structures were analyzed by means of DFT calculations. The Zn-Sn structure part of SrZn{sub 2}Sn{sub 2} comprises (anti-)PbO-like {l_brace}ZnSn{sub 4/4}{r_brace} and {l_brace}SnZn{sub 4/4}{r_brace} layers. Ca{sub 2}Zn{sub 3}Sn{sub 6} shows similar {l_brace}ZnSn{sub 4/4}{r_brace} layers and {l_brace}Sn{sub 4}Zn{r_brace} slabs constructed of a covalently bonded Sn scaffold capped by Zn atoms. For both phases, the two types of layers are alternatingly stacked and interconnected via Zn-Sn bonds. SrZn{sub 2}Sn{sub 2} adopts the SrPd{sub 2}Bi{sub 2} structure type, and Ca{sub 2}Zn{sub 3}Sn{sub 6} is isotypic to the R{sub 2}Zn{sub 3}Ge{sub 6} compounds (R=La, Ce, Pr, Nd). Band structure calculations indicate that both SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} are metallic. Analyses of the chemical bonding with the electron localization function (ELF) show lone pair like basins at Sn atoms and Zn-Sn bonding interactions between the layers for both title phases, and covalent Sn-Sn bonding within the {l_brace}Sn{sub 4}Zn{r_brace} layers of Ca{sub 2}Zn{sub 3}Sn{sub 6}. - Graphical abstract: Crystal structures of the new Ae-Zn-Sn polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Highlights: Black-Right-Pointing-Pointer New polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Black-Right-Pointing-Pointer Obtained by high temperature reactions of the elements. Black-Right-Pointing-Pointer Single crystal XRD structure determination and DFT electronic structure calculations. Black-Right-Pointing-Pointer Closely related crystal and electronic structures. Black-Right-Pointing-Pointer Metallic conductivity coexisting with lone pairs and covalent bonding features.

Stegmaier, Saskia [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany); Faessler, Thomas F., E-mail: Thomas.Faessler@lrz.tum.de [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany)

2012-08-15T23:59:59.000Z

63

Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application to photocatalysis  

E-Print Network [OSTI]

, the photocatalytic properties of the samples were investigated against the degradation of stearic acid under UV the degradation of stearic acid under UV-A light illumination (365 nm). We provide evidence that both ZnO and Zn photocatalytic activity regarding the degradation of stearic acid, due to their good crystallinity and large

64

The effect of ZnO surface conditions on the electronic structure of the ZnO/CuPc interface  

SciTech Connect (OSTI)

The interfacial electronic structures of zinc oxide (ZnO)/copper-phthalocyanine (CuPc) were investigated by in situ x-ray and ultraviolet photoelectron spectroscopy (UPS) to determine the effects of air contamination on the ZnO substrate. UPS spectra showed that the 0.2 eV of the interface dipole is generated at the interface of the air exposed ZnO/CuPc while the interface of the annealed ZnO/CuPc generated -0.2 eV. In both cases, no band bending was observed. On the other hand, band bending at 0.3 eV and an interface dipole of 0.2 eV were observed at the interface of the sputter cleaned ZnO/CuPc. The energy offset between the conduction band maximum of ZnO and the highest occupied molecular orbital of CuPc was determined to be 0.6-0.7 eV for the contaminated ZnO interface while the offset was 1.0 eV for the cleaned ZnO interface. Contaminating moisture has little effect on the offset while the charge transfer was blocked and the offset was decreased in the presence of hydrocarbons.

Park, Sang Han; Kim, Hyo Jin; Cho, Mann-Ho [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Yi, Yeonjin [Division of Industrial Metrology, KRISS, Daejeon 305-340 (Korea, Republic of); Cho, Sang Wan [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States); Yang, Jaehyun; Kim, Hyoungsub [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2011-02-21T23:59:59.000Z

65

ZnO/Cu(InGa)Se2 solar cells prepared by vapor phase Zn doping  

DOE Patents [OSTI]

A process for making a thin film ZnO/Cu(InGa)Se2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se2.

Ramanathan, Kannan; Hasoon, Falah S.; Asher, Sarah E.; Dolan, James; Keane, James C.

2007-02-20T23:59:59.000Z

66

Radioactive contamination of ZnWO4 crystal scintillators  

E-Print Network [OSTI]

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 -- 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopurity level of the ZnWO4 crystal scintillators is briefly addressed.

P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; A. M. Dubovik; S. d'Angelo; E. N. Galashov; B. V. Grinyov; A. Incicchitti; V. V. Kobychev; M. Laubenstein; L. L. Nagornaya; F. Nozzoli; D. V. Poda; R. B. Podviyanuk; O. G. Polischuk; D. Prosperi; V. N. Shlegel; V. I. Tretyak; I. A. Tupitsyna; Ya. V. Vasiliev; Yu. Ya. Vostretsov

2010-09-05T23:59:59.000Z

67

String-Net Models with $Z_N$ Fusion Algebra  

E-Print Network [OSTI]

We study the Levin-Wen string-net model with a $Z_N$ type fusion algebra. Solutions of the local constraints of this model correspond to $Z_N$ gauge theory and double Chern-simons theories with quantum groups. For the first time, we explicitly construct a spin-$(N-1)/2$ model with $Z_N$ gauge symmetry on a triangular lattice as an exact dual model of the string-net model with a $Z_N$ type fusion algebra on a honeycomb lattice. This exact duality exists only when the spins are coupled to a $Z_N$ gauge field living on the links of the triangular lattice. The ungauged $Z_N$ lattice spin models are a class of quantum systems that bear symmetry-protected topological phases that may be classified by the third cohomology group $H^3(Z_N,U(1))$ of $Z_N$. Our results apply also to any case where the fusion algebra is identified with a finite group algebra or a quantusm group algebra.

Ling-Yan Hung; Yidun Wan

2012-12-19T23:59:59.000Z

68

Methotrexate intercalated ZnAl-layered double hydroxide  

SciTech Connect (OSTI)

The anticancerous drug methotrexate (MTX) has been intercalated into an ZnAl-layered double hydroxide (LDH) using an anion exchange technique to produce LDH-MTX hybrids having particle sizes in the range of 100-300 nm. X-ray diffraction studies revealed increases in the basal spacings of ZnAl-LDH-MTX hybrid on MTX intercalation. This was corroborated by the transmission electron micrographs, which showed an increase in average interlayer spacing from 8.9 A in pristine LDH to 21.3 A in LDH-MTX hybrid. Thermogravimetric analyses showed an increase in the decomposition temperature for the MTX molecule in the LDH-MTX hybrid indicating enhanced thermal stability of the drug molecule in the LDH nanovehicle. The cumulative release profile of MTX from ZnAl-LDH-MTX hybrids in phosphate buffer saline (PBS) at pH 7.4 was successfully sustained for 48 h following Rigter-Peppas model release kinetics via diffusion. - Graphical abstract: ZnAl-layered double hydroxide intercalated with methotrexate ({approx}34% loading) promises the possibility of use of ZnAl-LDH material as drug carrier and in controlled delivery. Highlights: > ZnAl-layered double hydroxide methotrexate nanohybrid has been synthesized. > XRD and TEM studies on nanohybrid revealed successful intercalation of methotrexate. > TG and CHN analyses showed {approx}34 wt% of methotrexate loading into the nanohybrid. > Possibility of use of ZnAl-LDH material as drug carrier and in delivery.

Chakraborty, Manjusha; Dasgupta, Sudip; Soundrapandian, Chidambaram [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Chakraborty, Jui, E-mail: jui@cgcri.res.in [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Ghosh, Swapankumar, E-mail: swapankumar.ghosh2@mail.dcu.ie [National Institute for Interdisciplinary Science and Technology (NIIST), CSIR, Trivandrum 695019 (India); Mitra, Manoj K. [Department of Metallurgical and Materials Engineering, Jadavpur University, Kolkata 700032 (India); Basu, Debabrata [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)

2011-09-15T23:59:59.000Z

69

REGULAR ARTICLE Stability of polar ZnO surfaces studied by pair potential  

E-Print Network [OSTI]

density method Keju Sun · Hai-Yan Su · Wei-Xue Li Received: 1 September 2013 / Accepted: 16 November 2013. The overestimation of the stability of the ZnO(0001)­Zn terminal originates from more distribution of the transferred temperature sublimation processes indicated a higher sublimation rate of the ZnO(0001)­Zn surface compared

Li, Weixue

70

ZnO Nanocoral Structures for Photoelectrochemical Cells  

SciTech Connect (OSTI)

We report on synthesis of a uniform and large area of a new form of ZnO nanocorals. These nanostructures can provide suitable electrical pathways for efficient carrier collection as well as large surface areas for the photoelectrochemical (PEC) cells. PEC devices made from these ZnO nanocoral structures demonstrate significantly enhanced photoresponse as compared to ZnO compact and nanorod films. Our results suggest that the nanocoral structures could be an excellent choice for nanomaterial-based applications such as dye-sensitized solar cells, electrochromic windows, and batteries.

Ahn, K. S.; Yan, Y.; Shet, S.; Jones, K.; Deutsch, T.; Turner, J.; Al-Jassim, M.

2008-01-01T23:59:59.000Z

71

CdTe/CdZnTe pixellated radiation detector.  

E-Print Network [OSTI]

??The work in this thesis is focused on the study of CdTe/CdZnTe pixellated detectors. During this research, three main aspects have been covered in the (more)

Mohd Zain, Rasif

2015-01-01T23:59:59.000Z

72

Hot exciton transport in ZnSe quantum wells  

E-Print Network [OSTI]

The in-plane transport of excitons in ZnSe quantum wells is investigated directly by microphotoluminescence in combination with a solid immersion lens. Due to the strong Froehlich coupling, the initial kinetic energy of the excitons is well...

Zhao, Hui; Moehl, Sebastian; Wachter, Sven; Kalt, Heinz

2002-02-01T23:59:59.000Z

73

Compton profile study of polycrystalline ZnBr{sub 2}  

SciTech Connect (OSTI)

The first ever Compton profile study of polycrystalline ZnBr{sub 2} is presented in this paper. The measurement of polycrystalline sample of ZnBr{sub 2} is performed using 59.54 keV gamma-rays emanating from an {sup 241}Am radioisotope. Theoretical calculations are performed following the Ionic model calculations for a number of configurations Zn{sup +x}Br{sub 2}{sup -x/2}(0.0{<=}x{<=}2.0 in step of 0.5) utilizing free atom profiles. The ionic model suggest transfer of 2.0 electrons from 4 s state of Zn to 4 p state of two Br atoms. The autocorrelation function B(z) is also derived from experiment and the most favoured ionic valence Compton profiles.

Dhaka, M. S. [Department of Physics, Engineering College Bikaner, Bikaner, 334004, Rajasthan (India); Sharma, G. [Department of Physics, Bansthali University, Bansthali, 304022, Rajasthan (India); Mishra, M. C.; Kothari, R. K.; Sharma, B. K. [Department of Physics, University of Rajasthan, Jaipur, 302004, Rajasthan (India)

2010-12-01T23:59:59.000Z

74

Radioactive contamination of ZnWO4 crystal scintillators  

E-Print Network [OSTI]

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 ?? 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopur...

Belli, P; Cappella, F; Cerulli, R; Danevich, F A; Dubovik, A M; d'Angelo, S; Galashov, E N; Grinyov, B V; Incicchitti, A; Kobychev, V V; Laubenstein, M; Nagornaya, L L; Nozzoli, F; Poda, D V; Podviyanuk, R B; Polischuk, O G; Prosperi, D; Shlegel, V N; Tretyak, V I; Tupitsyna, I A; Vasiliev, Ya V; Vostretsov, Yu Ya

2010-01-01T23:59:59.000Z

75

Nanoscale order in ZnSe:(Mg, O)  

SciTech Connect (OSTI)

Self-assembling of 1O4Mg identical tetrahedral clusters resulting in the nanoscale order in ZnSe:(Mg, O) is presented. Co-doping transforms ZnSe into Mg{sub x}Zn{sub 1?x}O{sub y}Se{sub 1?y} alloy of MgO, MgSe, ZnO and ZnSe. The decrease of a sum of the enthalpies of the constituent compounds and diminution of the strain energy are the causes of this phenomenon. The self-assembling conditions are obtained from the free energy minimum when magnesium and oxygen are in the dilute and ultra dilute limits, correspondingly. The occurrence of 1O4Mg clusters and completion of self-assembling when all oxygen atoms are in clusters are results of the continuous phase transitions. The self-assembling occurrence temperature does not depend on the oxygen content and it is a function of magnesium concentration. Mg{sub x}Zn{sub 1?x}O{sub y}Se{sub 1?y} with all oxygen atoms in clusters can be obtained in temperature ranges from T = 206 C (x = 0.001, y = 110{sup ?4}) to T = 456 C (x = 0.01, y = 110{sup ?4}) and from T = 237 C (x = 0.001, y = 110{sup ?6}) to T = 462 C (x = 0.01, y = 110{sup ?6})

Elyukhin, Vyacheslav A. [Department of Electrical Engineering, Centro de Investigacin y de Estudios Avanzados del IPN, Avenida Instituto Politecnico Nacional 2508, 07360 Mxico (Mexico)

2014-02-21T23:59:59.000Z

76

Electron Transfer Between Colloidal ZnO Nanocrystals  

SciTech Connect (OSTI)

Colloidal ZnO nanocrystals capped with dodecylamine and dissolved in toluene can be charged photochemically to give stable solutions in which electrons are present in the conduction bands of the nanocrystals. These conduction-band electrons are readily monitored by EPR spectroscopy, with g* values that correlate with the nanocrystal sizes. Mixing a solution of charged small nanocrystals (e{sub CB}{sup -}:ZnO-S) with a solution of uncharged large nanocrystals (ZnO-L) caused changes in the EPR spectrum indicative of quantitative electron transfer from small to large nanocrystals. EPR spectra of the reverse reaction, e{sub CB}{sup -}:ZnO-L + ZnO-S, showed that electrons do not transfer from large to small nanocrystals. Stopped-flow kinetics studies monitoring the change in the UV bandedge absorption showed that reactions of 50 {micro}M nanocrystals were complete within the 5 ms mixing time of the instrument. Similar results were obtained for the reaction of charged nanocrystals with methyl viologen (MV{sup 2+}). These and related results indicate that the electron-transfer reactions of these colloidal nanocrystals are quantitative and very rapid, despite the presence of {approx}1.5 nm long dodecylamine capping ligands. These soluble ZnO nanocrystals are thus well-defined redox reagents suitable for studies of electron transfer involving semiconductor nanostructures.

Hayoun, Rebecca; Whitaker, Kelly M.; Gamelin, Daniel R.; Mayer, James M.

2011-03-30T23:59:59.000Z

77

Ordered zinc-vacancy induced Zn0.75Ox nanophase structure Yong Ding, Rusen Yang, Zhong Lin Wang *  

E-Print Network [OSTI]

Ordered zinc-vacancy induced Zn0.75Ox nanophase structure Yong Ding, Rusen Yang, Zhong Lin Wang induced by Zn-vacancy has been discovered to grow on wurtzite ZnO nanobelts. The superstructure grows parameters of ZnO. The superstructured phase is resulted from high-density Zn vacancies orderly distributed

Wang, Zhong L.

78

Non-oxidative reactions of propane on Zn/Na-ZSM5 Joseph A. Biscardi and Enrique Iglesia*  

E-Print Network [OSTI]

Non-oxidative reactions of propane on Zn/Na-ZSM5 Joseph A. Biscardi and Enrique Iglesia* Department rates during propane conversion at 773 K on Zn/Na-ZSM5 are about ten times higher than on Zn/H-ZSM5 catalysts with similar Zn content. The total rate of propane conversion is also higher on Zn/Na-ZSM5

Iglesia, Enrique

79

Syntheses, crystal structures and characterizations of BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2}  

SciTech Connect (OSTI)

Two new barium zinc selenite and tellurite, namely, BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2}, have been synthesized by the solid state reaction. The structure of BaZn(SeO{sub 3}){sub 2} features double chains of [Zn(SeO{sub 3}){sub 2}]{sup 2-} anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn{sub 2}(TeO{sub 3}){sub 2}Cl{sub 3}]{sup 3-} anions in BaZn(TeO{sub 3})Cl{sub 2} are formed by Zn{sub 3}Te{sub 3} rings in which each tellurite group connects with three ZnO{sub 3}Cl tetrahedra. BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2} are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements. -- Graphical abstract: Two new barium zinc selenite and tellurite, namely, BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2}, have been synthesized by solid state reaction. The structure of BaZn(SeO{sub 3}){sub 2} features 1D double chains of [Zn(SeO{sub 3}){sub 2}]{sup 2-} anions composed of four- and eight-member rings which are alternatively along a-axis. The 1D double chains of [Zn{sub 2}(TeO{sub 3}){sub 2}Cl{sub 3}]{sup 3-} anions in BaZn(TeO{sub 3})Cl{sub 2} are formed by Zn{sub 3}Te{sub 3} rings in which each tellurite group connects with one ZnO{sub 3}Cl and two ZnO{sub 2}Cl{sub 2} tetrahedra. BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2} are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements.

Jiang Hailong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China); Feng Meiling [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China); Mao Jianggao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China)]. E-mail: mjg@ms.fjirsm.ac.cn

2006-06-15T23:59:59.000Z

80

Stable highly conductive ZnO via reduction of Zn vacancies. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSiteNeutron Scattering4 By I.| EMSL ZnMnO3 Phase from

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Anisotropic strain effects on the photoluminescence emission from heteroepitaxial and homoepitaxial nonpolar (Zn,Mg)O/ZnO quantum wells  

SciTech Connect (OSTI)

We report on the properties of nonpolar a-plane (Zn,Mg)O/ZnO quantum wells (QW) grown by molecular beam epitaxy on r plane sapphire and a plane ZnO substrates. For the QWs grown on sapphire, the anisotropy of the lattice parameters of the (Zn,Mg)O barrier gives rise to an unusual in-plane strain state in the ZnO QWs, which induces a strong blue-shift of the excitonic transitions, in addition to the confinement effects. We observe this blue-shift in photoluminescence excitation experiments. The photoluminescence excitation energies of the QWs are satisfactorily simulated when taking into account the variation of the exciton binding energy with the QW width and the residual anisotropic strain. Then we compare the photoluminescence properties of homoepitaxial QWs grown on ZnO bulk substrate and heteroepitaxial QWs grown on sapphire. We show that the reduction of structural defects and the improvement of surface morphology are correlated with a strong enhancement of the photoluminescence properties: reduction of full width at half maximum, strong increase of the luminescence intensities. The comparison convincingly demonstrates the interest of homoepitaxial nonpolar QWs for bright UV emission applications.

Chauveau, J.-M.; Vinter, B. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); University of Nice Sophia Antipolis, Parc Valrose, F-06102 Nice Cedex 2 (France); Teisseire, M.; Morhain, C.; Deparis, C. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); Kim-Chauveau, H.

2011-05-15T23:59:59.000Z

82

Synthesis of reduced graphene oxide/ZnO nanorods composites on graphene coated PET flexible substrates  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: ZnO nanorods synthesized on CVD-graphene and rGO surfaces, respectively. ZnO/CVD-graphene and ZnO/rGO form a distinctive porous 3D structure. rGO/ZnO nanostructures possibility in energy storage devices. - Abstract: In this work, reduced graphene oxide (rGO)/ZnO nanorods composites were synthesized on graphene coated PET flexible substrates. Both chemical vapor deposition (CVD) graphene and reduced graphene oxide (rGO) films were prepared following by hydrothermal growth of vertical aligned ZnO nanorods. Reduced graphene sheets were then spun coated on the ZnO materials to form a three dimensional (3D) porous nanostructure. The morphologies of the ZnO/CVD graphene and ZnO/rGO were investigated by SEM, which shows that the ZnO nanorods grown on rGO are larger in diameters and have lower density compared with those grown on CVD graphene substrate. As a result of fact, the rough surface of nano-scale ZnO on rGO film allows rGO droplets to seep into the large voids of ZnO nanorods, then to form the rGO/ZnO hierarchical structure. By comparison of the different results, we conclude that rGO/ZnO 3D nanostructure is more desirable for the application of energy storage devices.

Huang, Lei, E-mail: leihuang@shnu.edu.cn; Guo, Guilue; Liu, Yang; Chang, Quanhong; Shi, Wangzhou

2013-10-15T23:59:59.000Z

83

Photoluminescence study of the substitution of Cd by Zn during the growth by atomic layer epitaxy of alternate CdSe and ZnSe monolayers  

SciTech Connect (OSTI)

We present a study of the substitution of Cd atoms by Zn atoms during the growth of alternate ZnSe and CdSe compound monolayers (ML) by atomic layer epitaxy (ALE) as a function of substrate temperature. Samples contained two quantum wells (QWs), each one made of alternate CdSe and ZnSe monolayers with total thickness of 12 ML but different growth parameters. The QWs were studied by low temperature photoluminescence (PL) spectroscopy. We show that the Cd content of underlying CdSe layers is affected by the exposure of the quantum well film to the Zn flux during the growth of ZnSe monolayers. The amount of Cd of the quantum well film decreases with higher exposures to the Zn flux. A brief discussion about the difficulties to grow the Zn{sub 0.5}Cd{sub 0.5}Se ordered alloy (CuAu-I type) by ALE is presented.

Hernndez-Caldern, I. [Physics Department,Cinvestav, Ave. IPN2508, 07360, Mxico City, DF. (Mexico); Salcedo-Reyes, J. C. [Thin Films Group, Physics Department, Pontificia Universidad Javeriana, Cr. 7 No. 43-82, Ed. 53, Lab. 404, Bogot, D.C. (Colombia)

2014-05-15T23:59:59.000Z

84

Photodynamic action of curcumin derived polymer modified ZnO nanocomposites  

SciTech Connect (OSTI)

Highlights: ? ZnO/PVA nano sensitized with curcumin and its metal complex were synthesized by vacuum evaporation method. ? M/cur sensitized on ZnO/PVA nanocomposites were characterized. ? Generation of {sup 1}O{sub 2} and ROS were detected by optical and EPR-spin trapping method. ? It was found that photoinduced cleavage of DNA using Zn/curZnO/PVA was superior. ? Photodegradation of MB in water catalyzed by ZnO/PVAZn/cur was also superior under visible light. -- Abstract: The photodynamic action of ZnO nano can be improved by modifying the surface by PVA and encapsulating the natural product, curcumin. The synthesized ZnO/PVA nanocomposites have been characterized using XRD, SEM, TEM, FTIR, TGDTA, etc. Here we are reporting the photodynamic effect of ZnO nanocomposites on pUC18 DNA. Based on optical and EPR measurements, singlet oxygen and other ROS were responsible for photocleavage of DNA. Most importantly, derived curcumin modified ZnO/PVA nanocomposites were comparatively more effective than derived curcumin complex against HeLa cell lines under in vitro condition. In addition, photodegradation of methylene blue (MB) in water catalyzed by nano ZnO/PVAcurcumin derivative was investigated at room temperature. Under visible irradiation photocatalytic activity of ZnO nanomaterial sensitized curcumin was higher than those of curcumin and nano ZnO.

Hariharan, R.; Senthilkumar, S. [P.G. Department of Chemistry, Cardamom Planters Association College, Bodinayakanur 625513, Tamil Nadu (India)] [P.G. Department of Chemistry, Cardamom Planters Association College, Bodinayakanur 625513, Tamil Nadu (India); Suganthi, A., E-mail: suganthiphd09@gmail.com [P.G. and Research Department of Chemistry, Thiagarajar College, Madurai 625009, Tamil Nadu (India); Rajarajan, M., E-mail: rajarajan_1962@yahoo.com [P.G. Department of Chemistry, Cardamom Planters Association College, Bodinayakanur 625513, Tamil Nadu (India)

2012-11-15T23:59:59.000Z

85

Structural Studies of Al:ZnO Powders and Thin Films | Stanford...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ingham, Associate Investigator, MacDiarmid Institute for Advanced Materials & Nanotechnology Al-doped ZnO (Al:ZnO) is a promising transparent conducting oxide. We have used...

86

Pressure Behaviour of the UV and Green Emission Bands in ZnO...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods. Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods. Abstract: The pressure behavior of...

87

E-Print Network 3.0 - al pb zn Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

et al., 1993; Dejonghe, 1998), resulting in elevated concentrations of Zn, Pb... by atomic absorption spectroscopy (AAS) for Zn, Pb, Mn, Fe, Ca, Mg, K and Al, and by...

88

An improved understanding of fluorescent Zn(II) sensors and their uses in biological settings  

E-Print Network [OSTI]

Chapter 1. An Introduction to Fluorescent Zn(II) Sensors and Their Applications in Biological Systems This chapter opens with an overview of the numerous roles of zinc in biology, with an emphasis on labile Zn(II), that ...

Wong, Brian Alexander

2009-01-01T23:59:59.000Z

89

Structural, optical and photocatalytic properties of ZnO thin films and  

E-Print Network [OSTI]

emitting diodes, gas sensors and transparent conducting thin films for solar cells. In this work, Zn an electronic furnace. Fig. 1. Grain size (black) and RMS variations (blue) of 1-6 layered ZnO films vs

90

Syngas Conversion to Gasoline-Range Hydrocarbons over Pd/ZnO...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Syngas Conversion to Gasoline-Range Hydrocarbons over PdZnOAl2O3 and ZSM-5 Composite Catalyst System. Syngas Conversion to Gasoline-Range Hydrocarbons over PdZnOAl2O3 and ZSM-5...

91

Enhanced photoelectrochemical responses of ZnO films through Ga and N codoping  

SciTech Connect (OSTI)

We report on the crystallinity and photoelectrochemical (PEC) response of ZnO thin films codoped by Ga and N. The ZnO:(Ga,N) thin films were deposited by cosputtering at room temperature and followed by postannealing at 500 deg. C in air for 2 h. We found that ZnO:(Ga,N) thin films exhibited significantly enhanced crystallinity compared to ZnO doped solely with N at the same growth conditions. Furthermore, ZnO:(Ga,N) thin films exhibited enhanced N incorporation over ZnO doped solely with N at high temperatures. As a result, ZnO:(Ga,N) thin films achieved dramatically improved PEC response, compared to ZnO thin films doped solely with N at any conditions. Our results suggest a general way to improve PEC response for wide-band-gap oxides.

Ahn, Kwang-Soon; Yan, Yanfa; Shet, Sudhakar; Deutsch, Todd; Turner, John; Al-Jassim, Mowafak [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

2007-12-03T23:59:59.000Z

92

PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol Steam Reforming, and Reverse-Water-Gas-Shift. PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol Steam...

93

CO/FTIR Spectroscopic Characterization of Pd/ZnO/Al2O3 Catalysts...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

COFTIR Spectroscopic Characterization of PdZnOAl2O3 Catalysts for Methanol Steam Reforming. COFTIR Spectroscopic Characterization of PdZnOAl2O3 Catalysts for Methanol Steam...

94

Fluorescent Dye Encapsulated ZnO Particles with Cell-specific...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dye Encapsulated ZnO Particles with Cell-specific Toxicity for Potential use in Biomedical Applications. Fluorescent Dye Encapsulated ZnO Particles with Cell-specific Toxicity...

95

Nitrogen is a deep acceptor in ZnO  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Zinc oxide is a promising material for blue and UV solid-state lighting devices, among other applications. Nitrogen has been regarded as a potential p-type dopant for ZnO. However, recent calculations [Lyons, Janotti, and Van de Walle, Appl. Phys. Lett. 95, 252105 (2009)] indicate that nitrogen is a deep acceptor. This paper presents experimental evidence that nitrogen is, in fact, a deep acceptor and therefore cannot produce p-type ZnO. A broad photoluminescence (PL) emission band near 1.7 eV, with an excitation onset of ~2.2 eV, was observed, in agreement with the deep-acceptor model of the nitrogen defect. The deep-acceptor behavior can be explained by the low energy of the ZnO valence band relative to the vacuum level.

McCluskey, M.D. [Washington State Univ., Pullman, WA (United States); Tarun, M.C. [Washington State Univ., Pullman, WA (United States); Iqbal, M. Zafar [COMSATS Institute of Information Technology, Islamabad (Pakistan)

2011-04-14T23:59:59.000Z

96

High mobility ZnO nanowires for terahertz detection applications  

SciTech Connect (OSTI)

An oxide nanowire material was utilized for terahertz detection purpose. High quality ZnO nanowires were synthesized and field-effect transistors were fabricated. Electrical transport measurements demonstrated the nanowire with good transfer characteristics and fairly high electron mobility. It is shown that ZnO nanowires can be used as building blocks for the realization of terahertz detectors based on a one-dimensional plasmon detection configuration. Clear terahertz wave (?0.3?THz) induced photovoltages were obtained at room temperature with varying incidence intensities. Further analysis showed that the terahertz photoresponse is closely related to the high electron mobility of the ZnO nanowire sample, which suggests that oxide nanoelectronics may find useful terahertz applications.

Liu, Huiqiang [State Key Laboratory of Optoelectronic Materials and Technology, Sun Yat-Sen University, Guangdong, Guangzhou 510275 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Sichuan, Mianyang 621010 (China); Peng, Rufang, E-mail: pengrufang@swust.edu.cn, E-mail: chusheng@mail.sysu.edu.cn; Chu, Shijin [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Sichuan, Mianyang 621010 (China); Chu, Sheng, E-mail: pengrufang@swust.edu.cn, E-mail: chusheng@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technology, Sun Yat-Sen University, Guangdong, Guangzhou 510275 (China)

2014-07-28T23:59:59.000Z

97

Process for fabricating ZnO-based varistors  

DOE Patents [OSTI]

The invention is a process for producing ZnO-based varistors incorporating a metal oxide dopant. In one form, the invention comprises providing a varistor powder mix of colloidal particles of ZnO and metal-oxide dopants including Bi.sub.2 O.sub.3. The mix is hot-pressed to form a compact at temperatures below 850.degree. C. and under conditions effecting reduction of the ZnO to sub-stoichiometric oxide. This promotes densification while restricting liquid formation and grain growth. The compact then is heated under conditions restoring the zinc oxide to stoichiometric composition, thus improving the varistor properties of the compact. The process produces fine-grain varistors characterized by a high actual breakdown voltage and a high average breakdown voltage per individual grain boundary.

Lauf, Robert J. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

98

Structural recovery of ion implanted ZnO nanowires G. Perillat-Merceroz,1, 2, a)  

E-Print Network [OSTI]

applications, ZnO nanowires are studied for making light- emitting diodes (LEDs) because of the advantages

Boyer, Edmond

99

Structure of graphene oxide dispersed with ZnO nanoparticles  

SciTech Connect (OSTI)

Graphene has been proposed as a promising two-dimensional nanomaterial with outstanding electronic, optical, thermal and mechanical properties for many applications. In present work a process of dispersion of graphene oxide with ZnO nanoparticles in ethanol solution with different pH values, have been studied. Samples have been characterized by XRD, SEM, PL, UV-visible spectroscopy and particles size measurement. The results analysis indicates overall improved emission spectrum. It has been observed that the average diameter of RGO (Reduced Graphene Oxide) decreases in presence of ZnO nanoparticles from 3.8?m to 0.41?m.

Yadav, Rishikesh, E-mail: rishikesh.yadav62@gmail.com; Pandey, Devendra K., E-mail: devendrakphy@gmail.com [School of Nanotechnology, Rajiv Gandhi Proudyogiki Vishwavidalaya, Bhopal, M.P. (India); Khare, P. S., E-mail: purnimaswarup@hotmail.com [Department of Physics, Rajiv Gandhi Proudyogiki Vishwavidalaya, Bhopal M.P. (India)

2014-10-15T23:59:59.000Z

100

Corrosion of, and cellular responses to MgZnCa bulk metallic glasses Xuenan Gu a  

E-Print Network [OSTI]

Corrosion of, and cellular responses to Mg­Zn­Ca bulk metallic glasses Xuenan Gu a , Yufeng Zheng a: Magnesium alloy Bulk metallic glass Mechanical property Corrosion Cytotoxicity a b s t r a c t Mg­Zn­Ca bulk, mechanical testing, corrosion and cytotoxicity tests. It was found that the Mg66Zn30Ca4 sample presents

Zheng, Yufeng

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Effect of the (OH) Surface Capping on ZnO Quantum Dots  

E-Print Network [OSTI]

in air at different temperatures from 150500 C for 30 min. In comparison, highly purified bulk Zn is related to oxygen deficiency [1]; the other is a much narrower ultraviolet (UV) emission band at around, compared with good quality ZnO single crystals or ZnO powders, the UV bandgap luminescence in quantum dots

Nabben, Reinhard

102

ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber photovoltaics  

SciTech Connect (OSTI)

Band alignments were measured by x-ray photoelectron spectroscopy for thin films of ZnO on polycrystalline Sn:In2O3 (ITO) and single crystal CdTe. Hybrid density functional theory calculations of epitaxial zinc blende ZnO(001) on CdTe(001) were performed to compare with experiment. A conduction band offset of -0.6 eV was measured for ZnO/ITO, which is larger than desired for efficient electron injection. For ZnO/CdTe, the experimental conduction band offset of 0.25 eV is smaller than the calculated value of 0.67 eV, likely due to the TeOx layer at the ZnO/CdTe interface. The measured conduction band offset for ZnO/CdTe is favorable for photovoltaic devices.

Kaspar, Tiffany C.; Droubay, Timothy C.; Jaffe, John E.

2011-12-28T23:59:59.000Z

103

ZnO Nanotube Based Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

ZnO Nanotube Based Dye-Sensitized Solar Cells Alex B. F. Martinson,, Jeffrey W. Elam, Joseph T templated by anodic aluminum oxide for use in dye-sensitized solar cells (DSSCs). Atomic layer deposition of the best dye- sensitized solar cells (DSSCs) is the product of a dye with moderate extinction

104

Atomic Absorption Method Guide Zn in Copper Alloys  

E-Print Network [OSTI]

Atomic Absorption Method Guide Zn in Copper Alloys Principle The sample is digested in nitric/hydrochloric acid, and zinc is determined by flame atomic absorption spectrometry using an air-acetylene flame · Copper Alloys · Zinc · Flame · Atomic Absorption Method Guide: 40158 #12;©2008 Thermo Fisher Scientific

Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

105

ZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY M.A. Contreras, 2  

E-Print Network [OSTI]

) photovoltaic technology is motivated primarily by the potential to enhance solar cell current generationZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY 1 M.A. Contreras, 2 T. Nakada, 2 M of 18.6% for Cu(In,Ga)Se2 solar cells that incorporate a ZnS(O,OH) buffer layer as an alternative to Cd

Sites, James R.

106

First principle study of elastic and thermodynamic properties of ZrZn{sub 2} and HfZn{sub 2} under high pressure  

SciTech Connect (OSTI)

A comprehensive investigation of the structural, elastic, and thermodynamic properties for Laves-phases ZrZn{sub 2} and HfZn{sub 2} are conducted using density functional total energy calculations combined with the quasi-harmonic Debye model. The optimized lattice parameters of ZrZn{sub 2} and HfZn{sub 2} compare well with available experimental values. We estimated the mechanical behaviors of both compounds under compression, including mechanical stability, Young's modulus, Poisson's ratio, ductility, and anisotropy. Additionally, the thermodynamic properties as a function of pressure and temperature are analyzed and found to be in good agreement with the corresponding experimental data.

Sun, Na; Zhang, Xinyu, E-mail: jiaqianqin@gmail.com; Ning, Jinliang; Zhang, Suhong; Liang, Shunxing; Ma, Mingzhen; Liu, Riping [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Qin, Jiaqian, E-mail: jiaqianqin@gmail.com [Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330 (Thailand)

2014-02-28T23:59:59.000Z

107

Development of a new electrodeposition process for plating of Zn-Ni-X (X=Cd, P) alloys. 1. Corrosion characteristics of Zn-Ni-Cd ternary alloys  

SciTech Connect (OSTI)

A new Zn-Ni-Cd plating process was developed which offers a unique way of controlling and optimizing the Ni and Cd contents in the final deposit. Zinc-nickel-cadmium alloy was deposited from a 0.5 M NiSO{sub 4} + 0.2 M ZnSO{sub 4} bath in the presence of 0.015 M CdSO{sub 4} and 1 g/L nonyl phenyl polyethylene oxide. Using this process a Zn-Ni-Cd ternary alloy, with a higher nickel content as compared to that obtained from conventional Zn-Ni baths, was synthesized. The Zn-Ni-Cd alloy coatings deposited from an electrolyte containing 0.015 M (0.3%) CdSO{sub 4} has a Zn to Ni ratio of 2.5:1. The increase in nickel content accounts for the observed decrease in the corrosion potential to a value lower than that of Cd but higher than the corrosion potential of iron. The coatings have superior corrosion resistance and barrier properties than the typical Zn-Ni and cadmium coatings. Polarization studies and electrochemical impedance spectroscopy analysis on Zn-Ni-Cd coatings show a barrier resistance that is ten times higher than that of a conventional Zn-Ni coating.

Durairajan, A.; Haran, B.S.; White, R.E.; Popov, B.N.

2000-05-01T23:59:59.000Z

108

Scintillating bolometers based on ZnMoO$_4$ and Zn$^{100}$MoO$_4$ crystals to search for 0$\  

E-Print Network [OSTI]

The technology of scintillating bolometers based on zinc molybdate (ZnMoO$_4$) crystals is under development within the LUMINEU project to search for 0$\

Poda, D V; Arnaud, Q; Augier, C; Benot, A; Berg, L; Boiko, R S; Bergmann, T; Blmer, J; Broniatowski, A; Brudanin, V; Camus, P; Cazes, A; Censier, B; Chapellier, M; Charlieux, F; Chernyak, D M; Coron, N; Coulter, P; Cox, G A; Danevich, F A; de Boissire, T; Decourt, R; De Jesus, M; Devoyon, L; Drillien, A -A; Dumoulin, L; Eitel, K; Enss, C; Filosofov, D; Fleischmann, A; Fourches, N; Gascon, J; Gastaldo, L; Gerbier, G; Giuliani, A; Gros, M; Hehn, L; Henry, S; Herv, S; Heuermann, G; Humbert, V; Ivanov, I M; Juillard, A; Kflian, C; Kleifges, M; Kluck, H; Kobychev, V V; Koskas, F; Kozlov, V; Kraus, H; Kudryavtsev, V A; Sueur, H Le; Loidl, M; Magnier, P; Makarov, E P; Mancuso, M; de Marcillac, P; Marnieros, S; Marrache-Kikuchi, C; Menshikov, A; Nasonov, S G; Navick, X-F; Nones, C; Olivieri, E; Pari, P; Paul, B; Penichot, Y; Pessina, G; Piro, M C; Plantevin, O; Redon, T; Robinson, M; Rodrigues, M; Rozov, S; Sanglard, V; Schmidt, B; Shlegel, V N; Siebenborn, B; Strazzer, O; Tcherniakhovski, D; Tenconi, M; Torres, L; Tretyak, V I; Vagneron, L; Vasiliev, Ya V; Velazquez, M; Viraphong, O; Walker, R J; Weber, M; Yakushev, E; Zhang, X; Zhdankov, V N

2015-01-01T23:59:59.000Z

109

Resorption Rate Tunable Bioceramic: Si, Zn-Modified Tricalcium Phosphate  

SciTech Connect (OSTI)

This dissertation is organized in an alternate format. Several manuscripts which have already been published or are to be submitted for publication have been included as separate chapters. Chapter 1 is a general introduction which describes the dissertation organization and introduces the human bone and ceramic materials as bone substitute. Chapter 2 is the background and literature review on dissolution behavior of calcium phosphate, and discussion of motivation for this research. Chapter 3 is a manuscript entitled ''Si,Zn-modified tricalcium phosphate: a phase composition and crystal structure study'', which was published in ''Key Engineering Materials'' [1]. Chapter 4 gives more crystal structure details by neutron powder diffraction, which identifies the position for Si and Zn substitution and explains the stabilization mechanism of the structure. A manuscript entitled ''Crystal structure analysis of Si, Zn-modified Tricalcium phosphate by Neutron Powder Diffraction'' will be submitted to Biomaterials [2]. Chapter 5 is a manuscript, entitled ''Dissolution behavior and cytotoxicity test of Si, Zn-modified tricalcium phosphate'', which is to be submitted to Biomaterials [3]. This paper discusses the additives effect on the dissolution behavior of TCP, and cytotoxicity test result is also included. Chapter 6 is the study of hydrolysis process of {alpha}-tricalcium phosphate in the simulated body fluid, and the phase development during drying process is discussed. A manuscript entitled ''Hydrolysis of {alpha}-tricalcium phosphate in simulated body fluid and phase transformation during drying process'' is to be submitted to Biomaterials [4]. Ozan Ugurlu is included as co-authors in these two papers due to his TEM contributions. Appendix A is the general introduction of the materials synthesis, crystal structure and preliminary dissolution result. A manuscript entitled ''Resorption rate tunable bioceramic: Si and Zn-modified tricalcium phosphate'' was published in Ceramic Engineering and Science Proceedings (the 29th International Conference on Advanced Ceramics and Composites - Advances in Bioceramics and Biocomposites) [5].

Xiang Wei

2006-08-09T23:59:59.000Z

110

Nano Res. 2012, 5(6): 412420412 Reshaping the Tips of ZnO Nanowires by Pulsed Laser  

E-Print Network [OSTI]

Nano Res. 2012, 5(6): 412­420412 Reshaping the Tips of ZnO Nanowires by Pulsed Laser Irradiation to the body of the ZnO nanowire, and that the center of the sphere is hollow. The growth mechanism of the hollow ZnO nanospheres is proposed to involve laser-induced ZnO evaporation immediately followed by re

Wang, Zhong L.

111

Structural and optical properties of MgO doped ZnO  

SciTech Connect (OSTI)

Samples of ZnO, Zn{sub 0.5}Mg{sub 0.5}O and MgO were prepared by co-precipitation method. X-ray diffraction (XRD) pattern infers that the sample of ZnO is in single-phase wurtzite structure (hexagonal phase, space group P6{sub 3}mc), MgO crystallizes in cubic Fd3m space group and Zn{sub 0.5}Mg{sub 0.5}O represents mixed nature of ZnO and MgO lattices. Similar features were observed from Raman spectroscopy. The energy band gaps estimated from UV-Vis spectroscopy are found to be 4.21 and 3.42 eV for ZnO and Zn{sub 0.5}Mg{sub 0.5}O samples respectively.

Verma, Kavita; Shukla, S.; Varshney, Dinesh, E-mail: vdinesh33@rediffmail.com [School of Physics, Vigyan Bhavan, Devi Ahilya University, Khandwa Road Campus, Indore-452001 (India); Varshney, M. [Department of Physics, M. B. Khalsa College, Raj Mohallah, Indore-452002 (India); Asthana, A. [Department of Chemistry, Govt. B. V. T. PG Autonomous College, Durg- 491001 (India)

2014-04-24T23:59:59.000Z

112

Optical transitions and multiphonon Raman scattering of Cu doped ZnO and MgZnO ceramics  

E-Print Network [OSTI]

of the Cu ion, Cu doped ZnO is a p-type semiconductor.13 Additionally, ferromagnetic behavior due were then dried and cold pressed at up to 3 tons for approximately 30 min, followed by annealing at a temperature of 10 K using a Bomem DA8 Fourier transform IR spectrometer and InSb detector. The micro

McCluskey, Matthew

113

Local structures of polar wurtzites Zn1-xMgxO studied by raman and 67Zn/25Mg NMR spectroscopies and by total neutron scattering  

SciTech Connect (OSTI)

Research in the area of polar semiconductor heterostructures has been growing rapidly, driven in large part by interest in two-dimensional electron gas (2DEG) systems. 2DEGs are known to form at heterojunction interfaces that bear polarization gradients. They can display extremely high electron mobilities, especially at low temperatures, owing to spatial confinement of carrier motions. Recent reports of 2DEG behaviors in Ga{sub 1-x}Al{sub x}N/GaN and Zn{sub 1-x}Mg{sub x}O/ZnO heterostructures have great significance for the development of quantum Hall devices and novel high-electron-mobility transistors (HEMTs). 2DEG structures are usually designed by interfacing a polar semiconductor with its less or more polar alloys in an epitaxial manner. Since the quality of the 2DEG depends critically on interface perfection, as well as the polarization gradient at the heterojunction, understanding compositional and structural details of the parent and alloy semiconductors is an important component in 2DEG design and fabrication. Zn{sub 1-x}Mg{sub x}O/ZnO is one of the most promising heterostructure types for studies of 2DEGs, due to the large polarization of ZnO, the relatively small lattice mismatch, and the large conduction band offsets in the Zn{sub 1-x}Mg{sub x}O/ZnO heterointerface. Although 2DEG formation in Zn{sub 1-x}Mg{sub x}O/ZnO heterostructures have been researched for some time, a clear understanding of the alloy structure of Zn{sub 1-x}Mg{sub x}O is currently lacking. Here, we conduct a detailed and more precise study of the local structure of Zn{sub 1-x}Mg{sub x}O alloys using Raman and solid-state nuclear magnetic resonance (NMR), in conjunction with neutron diffraction techniques.

Proffen, Thomas E [Los Alamos National Laboratory; Kim, Yiung- Il [UCSB; Cadars, Sylvian [UCSB; Shayib, Ramzy [UCSB; Feigerle, Charles S [UNIV OF TENNESSEE; Chmelka, Bradley F [UCSB; Seshadri, Ram [UCSB

2008-01-01T23:59:59.000Z

114

Growth of Single- and Bilayer ZnO on Au(111) and Interaction with Copper  

SciTech Connect (OSTI)

The stoichiometric single- and bi-layer ZnO(0001) have been prepared by reactive deposition of Zn on Au(111) and studied in detail with X-ray photoelectron spectroscopy, scanning tunneling microscopy, and density functional theory calculations. Both single- and bi-layer ZnO(0001) adopt a planar, graphite-like structure similar to freestanding ZnO(0001) due to the weak van der Waals interactions dominating their adhesion with the Au(111) substrate. At higher temperature, the single-layer ZnO(0001) converts gradually to bi-layer ZnO(0001) due to the twice stronger interaction between two ZnO layers than the interfacial adhesion of ZnO with Au substrate. It is found that Cu atoms on the surface of bi-layer ZnO(0001) are mobile with a diffusion barrier of 0.31 eV, and likely to agglomerate and form nanosized particles at low coverages; while Cu atoms tend to penetrate a single layer of ZnO(0001) with a barrier of 0.10 eV, resulting in a Cu free surface.

Deng, Xingyi; Yao, Kun; Sun, Keju; Li, Wei-Xue; Lee, Junseok; Matranga, Christopher

2013-05-30T23:59:59.000Z

115

NONLINEAR OPTICAL EFFECTS IN ROTATIONALLY-TWINNED CRYSTALS: AN EVALUATION OF CdTe, ZnTe AND ZnSe  

E-Print Network [OSTI]

-frequency and wavelength- tunable radiation from the ultraviolet to the far infrared region of the spectrum. Typical optical coefficients, (iii) the crystal must resist damage at the high power densities required405 NONLINEAR OPTICAL EFFECTS IN ROTATIONALLY-TWINNED CRYSTALS: AN EVALUATION OF CdTe, ZnTe AND Zn

Boyer, Edmond

116

Point Defect Characterization in CdZnTe  

SciTech Connect (OSTI)

Measurements of the defect levels and performance testing of CdZnTe detectors were performed by means of Current Deep Level Transient Spectroscopy (I-DLTS), Transient Charge Technique (TCT), Current versus Voltage measurements (I-V), and gamma-ray spectroscopy. CdZnTe crystals were acquired from different commercial vendors and characterized for their point defects. I-DLTS studies included measurements of defect parameters such as energy levels in the band gap, carrier capture cross sections, and defect densities. The induced current due to laser-generated carriers was measured using TCT. The data were used to determine the transport properties of the detectors under study. A good correlation was found between the point defects in the detectors and their performance.

Gul,R.; Li, Z.; Bolotnikov, A.; Keeter, K.; Rodriguez, R.; James, R.

2009-03-24T23:59:59.000Z

117

Experimental evidence of V{sub O}?Zn{sub i} complex to be intrinsic donor in bulk ZnO  

SciTech Connect (OSTI)

Theoretical evidence of V{sub O}?Zn{sub i} to be a native donor in bulk ZnO has been under debate. To resolve the issue, we annealed several pieces of as grown zinc rich n-type ZnO thin film having N{sub D} ? 3.26 10{sup 17} cm{sup ?3} grown by molecular beam epitaxy on Si (001) substrate in oxygen environment at 500C 800C, keeping a step of 100C for one hour, each. Room temperature Hall measurements demonstrated that free donor concentration decreased exponentially and Arrhenius plot yielded activation energy to be 1.20.02 eV. This value is in an agreement with the theoretically reported activation energy of V{sub O}?Zn{sub i} donor complex in ZnO.

Asghar, M.; Mahmood, K. [Department of Physics, The Islamia University of Bahawalpur 63100 (Pakistan); Hasan, M.-A; Tsu, R.; Ferguson, I. T. [Department of Electrical and Computer Engineering, University of North Carolina Charlotte, NC 28223 (United States)

2014-02-21T23:59:59.000Z

118

Acceptors in ZnO nanocrystals S. T. Teklemichael,1  

E-Print Network [OSTI]

as a buffer layer for growth of GaN-based devices,2 as a transparent conductive oxide Ref. 3 in solar cells,4- drate Zn CH3COO 2·2H2O and sodium hydrogen carbon- ate NaHCO3 are reacted at 200 °C for 3 h in an open cooling down to low tempera- ture. Electron paramagnetic resonance EPR measurements were carried out

McCluskey, Matthew

119

Electrodeposited ZnO films with high UV emission properties  

SciTech Connect (OSTI)

Highlights: {yields} Electrodeposition of ZnO from nitrate baths is investigated. {yields} The influence of process parameters on morphological and optical properties is studied. {yields} Experimental conditions to fabricate ZnO films with high UV emission were found. -- Abstract: We report here our results in the preparation of ZnO films with high UV band to band characteristic luminescence emission by potentiostatic electrodeposition. Zinc nitrate aqueous baths with different concentration and additives were employed for the preparation of the films on platinum substrates. We focused our research in determining how the electrodeposition bath composition, i.e. zinc nitrate concentration and addition of KCl or polyvinyl pyrolidone and applied overpotential influence the morphological and optical properties of the oxide films. Scanning electron microscopy was employed for characterizing the films in terms of morphology. Optical reflection, photoluminescence spectroscopy and cathodoluminescence were used for determining the optical characteristics of the samples. The morphology of the deposit varies from hexagonal prisms to platelets as a function of the deposition rate. This experimental parameter also influences the luminescence properties. We found that at low deposition rates high UV luminescent material is obtained.

Matei, Elena [National Institute of Materials Physics, PO Box MG 7, 77125 Magurele, Ilfov (Romania)] [National Institute of Materials Physics, PO Box MG 7, 77125 Magurele, Ilfov (Romania); Enculescu, Ionut, E-mail: encu@infim.ro [National Institute of Materials Physics, PO Box MG 7, 77125 Magurele, Ilfov (Romania)] [National Institute of Materials Physics, PO Box MG 7, 77125 Magurele, Ilfov (Romania)

2011-11-15T23:59:59.000Z

120

IR spectroscopy of lattice vibrations and comparative analysis of the ZnTe/CdTe quantum-dot superlattices on the GaAs substrate and with the ZnTe and CdTe buffer layers  

SciTech Connect (OSTI)

A comparative analysis of multiperiod ZnTe/CdTe superlattices with the CdTe quantum dots grown by molecular beam epitaxy on the GaAs substrate with the ZnTe and CdTe buffer layers is carried out. The elastic-stress-induced shifts of eigenfrequencies of the modes of the CdTe- and ZnTe-like vibrations of materials forming similar superlattices but grown on different buffer ZnTe and CdTe layers are compared. The conditions of formation of quantum dots in the ZnTe/CdTe superlattices on the ZnTe and CdTe buffer layers differ radically.

Kozyrev, S. P. [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)], E-mail: skozyrev@sci.lebedev.ru

2009-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Magnetism in undoped ZnS studied from density functional theory  

SciTech Connect (OSTI)

The magnetic property induced by the native defects in ZnS bulk, thin film, and quantum dots are investigated comprehensively based on density functional theory within the generalized gradient approximation + Hubbard U (GGA?+?U) approach. We find the origin of magnetism is closely related to the introduction of hole into ZnS systems. The relative localization of S-3p orbitals is another key to resulting in unpaired p-electron, due to Hund's rule. For almost all the ZnS systems under study, the magnetic moment arises from the S-dangling bonds generated by Zn vacancies. The charge-neutral Zn vacancy, Zn vacancy in 1? charge sate, and S vacancy in the 1+ charge sate produce a local magnetic moment of 2.0, 1.0, and 1.0??{sub B}, respectively. The Zn vacancy in the neutral and 1? charge sates are the important cause for the ferromagnetism in ZnS bulk, with a Curie temperature (T{sub C}) above room temperature. For ZnS thin film with clean (111) surfaces, the spins on each surface are ferromagnetically coupled but antiferromagnetically coupled between two surfaces, which is attributable to the internal electric field between the two polar (111) surfaces of the thin film. Only surface Zn vacancies can yield local magnetic moment for ZnS thin film and quantum dot, which is ascribed to the surface effect. Interactions between magnetic moments on S-3p states induced by hole-doping are responsible for the ferromagnetism observed experimentally in various ZnS samples.

Xiao, Wen-Zhi, E-mail: xiaowenzhi@hnu.edu.cn, E-mail: llwang@hun.edu.cn; Rong, Qing-Yan; Xiao, Gang [Department of Physics and Mathematics, Hunan Institute of Engineering, Xiangtan 411104 (China); Wang, Ling-ling, E-mail: xiaowenzhi@hnu.edu.cn, E-mail: llwang@hun.edu.cn [School of Physics and Microelectronics and Key Lab for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082 (China); Meng, Bo [College of Physics and Electronic Engineering, Caili University, Kaili 556011 (China)

2014-06-07T23:59:59.000Z

122

Supporting information for: Na-doped p-type ZnO , Faxian Xiu2  

E-Print Network [OSTI]

S1 Supporting information for: Na-doped p-type ZnO microwires Wei Liu1* , Faxian Xiu2 , Ke Sun1 flow was switched to argon followed by cooling to room temperature. After the growth, high-density Zn distribution of the Na Doped ZnO microwire 1.3 EDX line scans spectra #12;S3 Figure S3 a) a typical TEM image

Yang, Zheng

123

Green synthesis of graphene nanosheets/ZnO composites and electrochemical properties  

SciTech Connect (OSTI)

A green and facile approach was demonstrated to prepare graphene nanosheets/ZnO (GNS/ZnO) composites for supercapacitor materials. Glucose, as a reducing agent, and exfoliated graphite oxide (GO), as precursor, were used to synthesize GNS, then ZnO directly grew onto conducting graphene nanosheets as electrode materials. The small ZnO particles successfully anchored onto graphene sheets as spacers to keep the neighboring sheets separate. The electrochemical performances of these electrodes were analyzed by cyclic voltammetry, electrochemical impedance spectrometry and chronopotentiometry. Results showed that the GNS/ZnO composites displayed superior capacitive performance with large capacitance (62.2 F/g), excellent cyclic performance, and maximum power density (8.1 kW/kg) as compared with pure graphene electrodes. Our investigation highlight the importance of anchoring of small ZnO particles on graphene sheets for maximum utilization of electrochemically active ZnO and graphene for energy storage application in supercapacitors. - Graphical abstract: Glucose was used to synthesize GNS, then ZnO directly grew onto conducting graphene nanosheets as electrode materials for supercapacitor. Results showed that the composites have superior capacitive performance. Highlights: > Graphene nanosheets were synthesized via using glucose as a reducing agent. > The reductant and the oxidized product are environmentally friendly. > ZnO grew onto conducting graphene sheets keeping neighboring sheets separate. > The structure improves the contact between the electrode and the electrolyte. > Results showed that these composites have good electrochemical property.

Wang Jun, E-mail: zhqw1888@sohu.com [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin 150001 (China); Gao Zan [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin 150001 (China); Li Zhanshuang; Wang Bin; Yan Yanxia; Liu Qi [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Mann, Tom [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin 150001 (China); Zhang Milin [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin 150001 (China); Jiang Zhaohua [College of Chemical Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2011-06-15T23:59:59.000Z

124

Narrow Bandgap in beta-BaZn2As2 and Its Chemical Origins  

E-Print Network [OSTI]

Beta-BaZn2As2 is known to be a p-type semiconductor with the layered crystal structure similar to that of LaZnAsO, leading to the expectation that beta-BaZn2As2 and LaZnAsO have similar bandgaps; however, the bandgap of beta-BaZn2As2 (previously-reported value ~0.2 eV) is one order of magnitude smaller than that of LaZnAsO (1.5 eV). In this paper, the reliable bandgap value of beta-BaZn2As2 is determined to be 0.23 eV from the intrinsic region of the tem-perature dependence of electrical conductivity. The origins of this narrow bandgap are discussed based on the chemi-cal bonding nature probed by 6 keV hard X-ray photoemission spectroscopy, hybrid density functional calculations, and the ligand theory. One origin is the direct As-As hybridization between adjacent [ZnAs] layers, which leads to a secondary splitting of As 4p levels and raises the valence band maximum. The other is that the non-bonding Ba 5dx2-y2 orbitals form unexpectedly deep conduction band minimum (CBM) in beta-BaZn2As2 although the CBM of L...

Xiao, Zewen; Ueda, Shigenori; Toda, Yoshitake; Ran, Fan-Yong; Guo, Jiangang; Lei, Hechang; Matsuishi, Satoru; Hosono, Hideo; Kamiya, Toshio

2015-01-01T23:59:59.000Z

125

Structure of {sup 81}Ga populated from the {beta}{sup -} decay of {sup 81}Zn  

SciTech Connect (OSTI)

We report on the results of the {beta}-decay of {sup 81}Zn. The experiment was performed at the CERN ISOLDE facility in the framework of a systematic ultra-fast timing investigation of neutron-rich nuclei populated in the decay of Zn. The present analysis included {beta}-gated {gamma}-ray singles and {gamma}-{gamma} coincidences from the decay of {sup 81}Zn to {sup 81}Ga and leads to a new and much more extensive level scheme of {sup 81}Ga. A new half-life of {sup 81}Zn is provided.

Paziy, V.; Mach, H.; Fraile, L. M.; Olaizola, B.; Udias, J. M. [Grupo de Fisica Nuclear, Universidad Complutense, Madrid (Spain); Aprahamian, A.; Bucher, B. [Department of Physics, University of Notre Dame (United States); Bernards, C. [Institut fuer Kernphysik, Koeln, Germany. and Wright Nuclear Structure Laboratory, Yale University, New Haven, CT-06520 (United States); Briz, J. A. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain); Chiara, C. J. [Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, USA. and Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Dlouhy, Z. [Nuclear Physics Institute of the ASCR, Rez (Czech Republic); Gheorghe, I.; Ghita, D.; Lica, R.; Marginean, N.; Marginean, R.; Stanoiu, M.; Stroe, L. [National Institute for Physics and Nuclear Engineering, Magurele (Romania); Hoff, P. [Department of Chemistry, University of Oslo, Oslo (Norway); Koester, U. [Institut Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble Cedex 9 (France); and others

2013-06-10T23:59:59.000Z

126

Transport and magnetotransport study of Mg doped ZnO thin films  

SciTech Connect (OSTI)

We report negative magnetoresistance in pulsed laser deposited single phase ZnO and Mg{sub 0.268}Zn{sub 0.732}O films and attribute it to the presence of oxygen interstitials (O{sub i}) and zinc interstitials (Zn{sub i}) as observed in the X-ray photoelectron spectra of the films. An interesting feature of reduction of negative magnetoresistance at low temperatures and large fields in Mg{sub 0.268}Zn{sub 0.732}O film is observed and is explained by taking into account the localized scattering.

Agrawal, Arpana; Dar, Tanveer A., E-mail: tanveerphysics@gmail.com; Sen, Pratima [Laser Bhawan, School of Physics, Devi Ahilya University, Indore 452 017 (India); Phase, Deodatta M. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India)

2014-04-14T23:59:59.000Z

127

Optical and morphological properties of graphene sheets decorated with ZnO nanowires via polyol enhancement  

SciTech Connect (OSTI)

Graphene-ZnO nanocomposites have proven to be very useful materials for photovoltaic and sensor applications. Here, we report a facile, one-step in situ polymerization method for synthesis of graphene sheets randomly decorated with zinc oxide nanowires using ethylene glycol as solvent. We have used hydrothermal treatment for growth of ZnO nanowires. UV-visible spectra peak shifting around 288nm and 307 nm shows the presence of ZnO on graphene structure. Photoluminiscence spectra (PL) in 400nm-500nm region exhibits the luminescence quenching effect. Scanning electron microscopy (SEM) image confirms the growth of ZnO nanowires on graphene sheets.

Sharma, Vinay, E-mail: winn201@gmail.com; Rajaura, Rajveer Singh, E-mail: winn201@gmail.com [Centre for Converging Technologies, University of Rajasthan, Jaipur - 302004 (India); Sharma, Preetam K.; Srivastava, Subodh; Vijay, Y. K. [Department of Physics, Thin Film and Membrane Science Lab., University of Rajasthan, Jaipur - 302004 (India); Sharma, S. S. [Department of Physics, Govt. Women Engineering College, Ajmer- 305002 (India)

2014-04-24T23:59:59.000Z

128

Crystal growth behaviour in Au-ZnO nanocomposite under different annealing environments and photoswitchability  

SciTech Connect (OSTI)

The growth of gold nanoparticles and ZnO nanorods in atom beam co-sputtered Au-ZnO nanocomposite (NC) system by annealing at two different ambient conditions is demonstrated in this work. Annealing in a furnace at 600 Degree-Sign C (air environment) confirmed the formation of ZnO nanorods surrounded with Au nanoparticles. In-situ annealing inside a transmission electron microscope (TEM) led to the formation of gold nanocrystals with different polygonal shapes. TEM micrographs were obtained in real time at intermediate temperatures of 300 Degree-Sign C, 420 Degree-Sign C, and 600 Degree-Sign C under vacuum. The growth mechanisms of Au nanocrystals and ZnO nanorods are discussed in the framework of Au-Zn eutectic and Zn-melting temperatures in vacuum and air, respectively. Current-voltage responses of Au-ZnO NC nanorods in dark as well as under light illumination have been investigated and photoswitching in Au-ZnO NC system is reported. The photoswitching has been discussed in terms of Au-ZnO band-diagram.

Mishra, Y. K.; Adelung, R. [Functional Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel (Germany); Chakravadhanula, V. S. K.; Hrkac, V.; Kienle, L. [Synthesis and Real Structure, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel (Germany); Jebril, S. [Multicomponent Materials, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel (Germany); Agarwal, D. C.; Avasthi, D. K. [Inter University Accelerator Centre, Post Box 10502, New Delhi 110067 (India); Mohapatra, S. [University School of Basic and Applied Sciences, GGS Indraprastha University, Dwaraka, New Delhi 110075 (India)

2012-09-15T23:59:59.000Z

129

Phase diagram, crystal chemistry and thermoelectric properties of compounds in the Ca?Co?Zn?O system  

SciTech Connect (OSTI)

In the Ca-Co-Zn-O system, we have determined the tie-line relationships and the thermoelectric properties, solid solution limits, and structures of two low-dimensional cobaltite series, Ca{sub 3}(Co, Zn){sub 4}O{sub 9-z} and Ca{sub 3}(Co,Zn){sub 2}O{sub 6-z} at 885 C in air. In Ca{sub 3}(Co,Zn){sub 4}O{sub 9-z}, which has a misfit layered structure, Zn was found to substitute in the Co site to a limit of Ca{sub 3}(Co{sub 3.8}Zn{sub 0.2})O{sub 9-z}. The compound Ca{sub 3}(Co,Zn){sub 2}O{sub 6-z} (n=1 member of the homologous series, Ca{sub n+2}(Co,Zn)n(Co,Zn)'O{sub 3n+3-z}) consists of one-dimensional parallel (Co,Zn){sub 2}O{sub 6}{sup 6-} chains that are built from successive alternating face-sharing (Co,Zn)O{sub 6} trigonal prisms and 'n' units of (Co,Zn)O{sub 6} octahedra along the hexagonal c-axis. Zn substitutes in the Co site of Ca{sub 3}Co{sub 2}O{sub 6} to a small amount of approximately Ca{sub 3}(Co{sub 1.95}Zn{sub 0.05})O{sub 6-z}. In the ZnO-CoO{sub z} system, Zn substitutes in the tetrahedral Co site of Co{sub 3}O{sub 4} to the maximum amount of (Co{sub 2.49}Zn{sub 0.51})O{sub 4-z} and Co substitutes in the Zn site of ZnO to (Zn{sub 0.94}Co{sub 0.06})O. The crystal structures of (Co{sub 2.7}Zn{sub 0.3})O{sub 4-z}, (Zn{sub 0.94}Co{sub 0.06})O, and Ca{sub 3}(Co{sub 1.95} Zn{sub 0.05})O{sub 6-z} are described. Despite the Ca{sub 3}(Co, Zn){sub 2}O{sub 6-z} series having reasonably high Seebeck coefficients and relatively low thermal conductivity, the electrical resistivity values of its members are too high to achieve high figure of merit, ZT.

Wong-Ng, W.; Luo, T.; Xie, W.; Tang, W.H.; Kaduk, J.A.; Huang, Q.; Yan, Y.; Chattopadhyay, S.; Tang, X.; Tritt, T. (IIT); (Clemson); (NIST); (Maryland); (Zhejiang); (Wuhan)

2011-11-17T23:59:59.000Z

130

Visualization of Peroxynitrite-Induced Changes of Labile Zn[superscript 2+] in the Endoplasmic Reticulum with Benzoresorufin-based Fluorescent Probes  

E-Print Network [OSTI]

Zn[superscript 2+] plays essential roles in biology, and the homeostasis of Zn[superscript 2+] is tightly regulated in all cells. Subcellular distribution and trafficking of labile Zn[superscript 2+], and its inter-relation ...

Lin, Wei

131

Piezospectroscopic study of substitutional Ni in ZnO  

SciTech Connect (OSTI)

The effect of uniaxial stress on the electronic {sup 3}T{sub 1}(F)?{sup 3}T{sub 2}(F) transitions of Ni{sup 2+} in ZnO at 4216, 4240, and 4247 cm{sup ?1} is investigated by means of Fourier transform IR absorption spectroscopy. A stress Hamiltonian is constructed which accounts for the behavior of these transitions under uniaxial stress. It is shown that the split pattern and polarization properties of these IR absorption lines are consistent with a dynamic Jahn-Teller effect in the {sup 3}T{sub 2}(F) state of Ni.

Lavrov, E. V.; Herklotz, F. [Technische Universitt Dresden, 01062 Dresden (Germany); Kutin, Y. S. [Kazan Federal University, Federal Center of Shared Facilities, 420008 Kazan (Russian Federation)

2014-02-21T23:59:59.000Z

132

ZnO nanoclusters: Synthesis and photoluminescence. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched FerromagnetismWaste andAnniversary, part 2Zenoss, VersionThe Role ofZnO nanoclusters:

133

Growth mechanism and properties of ZnO nanorods synthesized by plasma-enhanced chemical vapor deposition  

E-Print Network [OSTI]

and ul- traviolet (UV) optoelectronic devices. ZnO can be found easily as n-type because of Zn. Trans- parent electrodes in optoelectronic devices should have high visible transmittance, low

Cao, Hui

134

Infrared spectroscopy of lattice vibrations in ZnTe/CdTe superlattices with quantum dots on the GaAs substrate with the ZnTe buffer layer  

SciTech Connect (OSTI)

The results of the analysis of the infrared lattice reflectance spectra of multiperiod ZnTe/CdTe superlattices with CdTe quantum dots are reported. The samples are grown by molecular beam epitaxy on the GaAs substrate with the ZnTe buffer layer. Due to the large number of periods of the superlattices, it is possible to observe CdTe-like vibration modes in the quantum dots, i.e., the dislocation-free stressed islands formed during the growth due to relaxation of elastic stresses between the ZnTe and CdTe layers are markedly different in their lattice parameters. From the frequency shifts of the CdTe- and ZnTe-like vibration modes with respect to the corresponding modes in the unstressed materials, it is possible to estimate the level of elastic stresses.

Kozyrev, S. P. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)], E-mail: skozyrev@sci.lebedev.ru

2009-03-15T23:59:59.000Z

135

Residual Stress Relaxation and Microstructure in ZnO Thin Films Istem Ozena  

E-Print Network [OSTI]

to be eliminated during deposition. Introduction In this study, the decay of the residual stressesResidual Stress Relaxation and Microstructure in ZnO Thin Films Istem Ozena and Mehmet Ali Gulgunb. a istem@sabanciuniv.edu b m-gulgun@sabanciuniv.edu Keywords: ZnO, thin films, residual stress

Yanikoglu, Berrin

136

Structure and magnetic properties of rf thermally plasma synthesized Mn and MnZn ferrite nanoparticles  

E-Print Network [OSTI]

Structure and magnetic properties of rf thermally plasma synthesized Mn and Mn­Zn ferrite has previously been shown to be a viable route to producing nanocrystalline magnetite and Ni ferrite nanoparticles. In this work nanocrystalline powders of Mn and Mn­Zn ferrites have been synthesized using a 50 k

McHenry, Michael E.

137

An Analysis of Mn-Zn Ferrite Microstructure by Impedance Spectroscopy, STEM and EDS Characterisations.  

E-Print Network [OSTI]

An Analysis of Mn-Zn Ferrite Microstructure by Impedance Spectroscopy, STEM and EDS.loyau@satie.ens-cachan.fr Abstract AC resistivity measurement results on Mn-Zn sintered ferrite were analyzed in the 0.1-500 MHz of the main limitations in frequency increase is the energy dissipations by losses in ferrites that produce

Boyer, Edmond

138

Microstructural Evolution Model of the Sintering Behavior and Magnetic Properties of NiZn Ferrite Nanoparticles  

E-Print Network [OSTI]

Microstructural Evolution Model of the Sintering Behavior and Magnetic Properties of NiZn Ferrite jlwoods@andrew.cmu.edu, c SCalvin@slc.edu, d jhuth@Spang.co, e mm7g@andrew.cmu.edu Keywords: Ferrite, nanoparticle, sintering, microstructure. Abstract. The sintering of RF plasma synthesized NiZn ferrite

McHenry, Michael E.

139

Recycling ZnTe, CdTe, and Other Compound Semiconductors by Ambipolar Electrolysis  

E-Print Network [OSTI]

The electrochemical behavior of ZnTe and CdTe compound semiconductors dissolved in molten ZnCl[subscript 2] and equimolar CdCl[subscript 2]KCl, respectively, was examined. In these melts dissolved Te is present as the ...

Osswald, Sebastian

140

Preparation of patterned graphene-ZnO hybrid nanoflower and nanorods on ITO surface  

SciTech Connect (OSTI)

Hybrid ZnO nanostructure with controlled morphology have been proved to enhance the physical and chemical properties of the material and used as photodiode and sensor. In this paper, hybrid graphene-ZnO nanoflower and nanorods have been successfully synthesized via a seed mediated method with micropatterned ZnO nanoseed treated with multilayer graphene (MLG) in a hydrothermal process. In typical process, the ZnO nanoseeds with and without resists were spin coated with a multilayer graphene prior to the growth process. The treated seed was then used to grow the ZnO nanostructures in the growth solution that contained equimolar (0.04 M) of zinc nitrate hexahydrate and hexamethylenetetramine. The growth process was carried out inside an autoclave at temperature 70 C. The growth time was 4 h. It was proved that the MLG treatment on micropatterning substrate may induce new morphology formation of ZnO nanostructure. It is expected that the heteroepitaxy reaction occurred between the MLG and ZnO interface. This presence method can be used as an alternative approach to control the morphology of hybrid ZnO nanostructure growth.

Tan, Sin Tee; Umar, Marjoni Imamora Ali; Ginting, Riski Titian; Yahaya, Muhammad; Yap, Chi Chin [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Umar, Akrajas Ali; Salleh, Muhamad Mat; Majlis, Burhanuddin Yeop; Naumar, Fitri Yenni [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2013-11-27T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Hybrid Electrochromic Fluorescent Poly(DNTD)/CdSe@ZnS Composite Films  

E-Print Network [OSTI]

Hybrid Electrochromic Fluorescent Poly(DNTD)/CdSe@ZnS Composite Films Huige Wei, Xingru Yan, Springdale, Arkansas 72764, United States ABSTRACT: Hybrid electrochromic poly(DNTD)/CdSe@ZnS quantum dots of an electrical current after the application of an appropriate electrode potential.15-17 The electrochromic

Guo, John Zhanhu

142

Fabrication of Microfibre-nanowire Junction Arrays of ZnO/SnO2 Composite  

E-Print Network [OSTI]

nanocomposite sensitized with a D35-cpdt dye was investigated. A dye-sensitized solar cell (DSSC) with a Zn discussed. Keywords ZnO/SnO2 Nanocomposite, Dye-sensitized Solar Cell, Nanostructured Surfaces 1O/SnO2 nanocomposite photoanode based on a cobalt electrolyte achieved a solar-to-electricity conversion

Iglic, Ales

143

DOI: 10.1002/adfm.200701073 Polydisperse Aggregates of ZnO Nanocrystallites: A Method  

E-Print Network [OSTI]

-Conversion-Efficiency Enhancement in Dye-Sensitized Solar Cells** By Qifeng Zhang, Tammy P. Chou, Bryan Russo, Samson A. Jenekhe, and Guozhong Cao* 1. Introduction ZnO-based dye-sensitized solar cells (DSSCs) have attrac- ted considerable a relatively efficient dye-sensitized ZnO solar cell with a conversion efficiency of $3

Cao, Guozhong

144

DOI: 10.1002/adma.200702781 Aerogel Templated ZnO Dye-Sensitized Solar Cells**  

E-Print Network [OSTI]

DOI: 10.1002/adma.200702781 Aerogel Templated ZnO Dye-Sensitized Solar Cells** By Thomas W. Hamann silica aerogel films, featuring a large range of controllable thickness and porosity, are prepared as substructure templates. The aerogel templates are coated with ZnO via atomic layer deposition (ALD) to yield

145

The "calamine" nonsulfide ZnPb deposits of Belgium: Petrographical, mineralogical and geochemical characterization  

E-Print Network [OSTI]

" and consist of a mixture of Zn carbonates (smithsonite, hydrozincite) and Zn silicates (hemimorphite-Variscan hydrothermal veins and replacement bodies, mostly occurring in the Dinantian (Visean) limestones. The sulfides of other willemite ores throughout the world, so far considered of hydrothermal origin. The stable isotope

Boni, Maria

146

Terahertz Dielectric Properties and Low-Frequency Phonon Resonances of ZnO Nanostructures  

E-Print Network [OSTI]

. The dielectric function of tubular and prismlike ZnO structures exhibits the Drude-like behavior, while spectral region, and therefore it can be used as the transparent conductive electrodes in solar cells and flat panel displays.10 Additionally, surface acoustic wave filters made from ZnO films have been used

147

Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation  

E-Print Network [OSTI]

- grade their optical properties. In this paper, we report on the effects of gamma irradiationRapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation Nathan J. Withers of 137 Cs gamma irradiation on photoluminescent properties of CdSe/ZnS colloidal quantum dots

New Mexico, University of

148

Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma,  

E-Print Network [OSTI]

Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma, Burak Guzelturk, Talha report white-light-emitting Mn-doped ZnSe nanocrystals (NCs) that are synthesized using modified orange emission (580 nm), allowed us to achieve excitation wavelength tailorable white-light generation

Demir, Hilmi Volkan

149

A Novel Electrodeposition Process for Plating Zn-Ni-Cd Alloys Hansung Kim,a,  

E-Print Network [OSTI]

A Novel Electrodeposition Process for Plating Zn-Ni-Cd Alloys Hansung Kim,a, * Branko N. Popov Sciences Center, Albuquerque, New Mexico 87185-0834, USA Zn-Ni-Cd alloy was electrodeposited from in the literature.7-9 Typical nickel composition in the alloy is approximately 10%, and any further increase

Popov, Branko N.

150

Diamond-machined ZnSe immersion grating for NIR high-resolution spectroscopy  

SciTech Connect (OSTI)

ZnSe immersion gratings (n {approx} 2.45) provide the possibility of high-resolution spectroscopy for the near-infrared (NIR) region. Since ZnSe has a lower internal attenuation than other NIR materials, it is most suitable for immersion grating, particularly in short NIR region (0.8-1.4 {micro}m). We are developing an extremely high-resolution spectrograph with {lambda}/{Delta}{lambda} = 100,000, WINERED, customized for the short NIR region, using ZnSe (or ZnS) immersion grating. However, it had been very difficult to make fine grooves on ZnSe substrate with a small pitch of less than 50 {micro}m because ZnSe is a soft/brittle material. We have overcome this problem and successfully machined sharp grooves with fine pitch on ZnSe substrates by nano precision fly-cutting technique at LLNL. The optical testing of the sample grating with HeNe laser shows an excellent performance: the relative efficiency more than 87.4 % at 0.633 {micro}m for a classical grating configuration. The diffraction efficiency when used as an immersion grating is estimated to be more than 65 % at 1 {micro}m. Following this progress, we are about to start machining a grating on a large ZnSe prism with an entrance aperture of 23mm x 50mm and the blaze angle of 70{sup o}.

Ikeda, Y; Kobayashi, N; Kuzmenko, P J; Little, S L; Yasui, C; Kondo, S; Minami, A; Motohara, K

2008-07-25T23:59:59.000Z

151

Thickness influence on surface morphology and ozone sensing properties of nanostructured ZnO transparent  

E-Print Network [OSTI]

, 71004 Heraklion, Crete, Greece Available online 19 January 2006 Abstract Transparent zinc oxide (Zn Keywords: Zinc oxide; PLD; AFM; Ozone 1. Introduction Zinc oxide (ZnO) is an n-type semiconductor devices [3], varistors, planar optical waveguides [4], transparent electrodes [5,6], ultraviolet

152

Water adsorption on stepped ZnO surfaces from MD simulation David Raymand a  

E-Print Network [OSTI]

Water adsorption on stepped ZnO surfaces from MD simulation David Raymand a , Adri C.T. van Duin b Keywords: Zinc oxide Water Solid­gas interfaces Construction and use of effective interatomic interactions force-field for use in molecular dynamics simulations of the ZnO­ water system. The force

Goddard III, William A.

153

Coplanar grid CdZnTe detectors for space science applications Benjamin W. Sturm*a  

E-Print Network [OSTI]

Coplanar grid CdZnTe detectors for space science applications Benjamin W. Sturm*a , Zhong Hea of the latest coplanar grid CdZnTe detectors, which use the third- generation coplanar grid design into the material properties as well as the charge induction uniformity of the detector. Keywords: coplanar grid, Cd

He, Zhong

154

Degradation of ZnO Window Layer for CIGS by Damp-Heat Exposure: Preprint  

SciTech Connect (OSTI)

This paper summarizes our work with more details and an emphasis on the DH-induced degradation of Al-doped ZnO and Zn1-xMgxO alloys. The other two TCOs, ITO and F:SnO2, are not included here.

Pern, F.J.; To, B.; DeHart, C.; Li, X.; Glick, S. H.; Noufi, R.

2008-08-01T23:59:59.000Z

155

Heteroepitaxial ZnO films on diamond: Optoelectronic properties and the role of interface polarity  

SciTech Connect (OSTI)

We demonstrate the growth of heteroepitaxial ZnO films on (110) diamond substrates by molecular beam epitaxy and report on a major advance in structural quality, as confirmed by XRD and high-resolution TEM measurements. The growth direction is found to be along the polar c-axis with Zn-polarity, deduced from annular bright-field scanning transmission electron microscopy imaging. This is important information, as simulations of the electronic band structure reveal the ZnO polarity to dominate the electronic structure of the interface: the formation of a two-dimensional electron gas on the ZnO side or a two-dimensional hole gas on the diamond side are predicted for Zn- and O-polarity, respectively. In addition, photoluminescence and absorption studies exhibit good optical properties and reveal stimulated emission for optical excitation above a threshold of 30?kW/cm{sup 2}.

Schuster, Fabian, E-mail: Fabian.Schuster@wsi.tum.de; Hetzl, Martin; Garrido, Jose A.; Stutzmann, Martin [Walter Schottky Institut, Technische Universitt Mnchen, Am Coulombwall 4, 85748 Garching (Germany); Magn, Cesar [Laboratorio de Microscopas Avanzadas (LMA) - Instituto de Nanociencia de Aragon (INA) and Departamento de Fsica de la Materia Condensada, Universidad de Zaragoza, 50018 Zaragoza (Spain); Fundacin ARAID, 50018 Zaragoza (Spain); Arbiol, Jordi [Institut de Cincia de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra, CAT (Spain); Instituci Catalana de Recerca i Estudis Avanats (ICREA), 08010 Barcelona, CAT (Spain)

2014-06-07T23:59:59.000Z

156

Direct kinetic correlation of carriers and ferromagnetism in Co2+ : ZnO  

SciTech Connect (OSTI)

We report the use of controlled introduction and removal of Zni to test the hypothesis that high-Curie-temperature ferromagnetism in cobalt-doped ZnO (Co2+:ZnO) is mediated by carriers. Using oriented epitaxial Co2+:ZnO films grown by chemical vapor deposition, kinetics measurements were used to correlate the oxidative quenching of ferromagnetism with the diffusion and oxidation of interstitial zinc. These results demonstrate controlled systematic variation of a key parameter involved in the ferromagnetism of Co2+:ZnO, namely interstitial zinc, and in the process unambiguously reveal this ferromagnetism to be dependent upon carriers. The distinction between defect-bound and free carriers in Co2+:ZnO is discussed

Kittilstved, Kevin R.; Schwartz, Dana A.; Tuan, Allan C.; Heald, Steve M.; Chambers, Scott A.; Gamelin, Daniel R.

2006-07-21T23:59:59.000Z

157

Luminescence properties of ZnO layers grown on Si-on-insulator substrates  

SciTech Connect (OSTI)

The authors report on the photoluminescence properties of polycrystalline ZnO thin films grown on compliant silicon-on-insulator (SOI) substrates by radio frequency magnetron sputtering. The ZnO thin films on SOI were characterized by micro-Raman and photoluminescence (PL) spectroscopy. The observation of E{sub 2}{sup high} optical phonon mode near 438 cm{sup -1} in the Raman spectra of the ZnO samples represents the wurtzite crystal structure. Apart from the near-band-edge free exciton (FX) transition around 3.35 eV at 77 K, the PL spectra of such ZnO films also showed a strong defect-induced violet emission peak in the range of 3.05-3.09 eV. Realization of such ZnO layers on SOI would be useful for heterointegration with SOI-based microelectronics and microelectromechanical systems.

Kumar, Bhupendra; Gong, Hao; Vicknesh, S.; Chua, S. J.; Tripathy, S. [Department of Materials Science and Engineering, National University of Singapore, 119260 Singapore (Singapore); Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore)

2006-10-02T23:59:59.000Z

158

ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched FerromagnetismWaste andAnniversary, part 2Zenoss, VersionThe Role ofZnO

159

Corrosion Protection of Steel Using Nonanomalous Ni-Zn-P Basker Veeraraghavan,* Bala Haran,** Swaminatha P. Kumaraguru,*  

E-Print Network [OSTI]

Corrosion Protection of Steel Using Nonanomalous Ni-Zn-P Coatings Basker Veeraraghavan,* Bala Haran on the corrosion resistance of the final deposit. Coatings with 16.2 wt % Zn were found to display a potential of 0 of the coating and the surface morphology. Corrosion studies in corroding media show that Ni-Zn-P coatings

Popov, Branko N.

160

Phase transformation of ZnMoO{sub 4} by localized thermal spike  

SciTech Connect (OSTI)

We show that ZnMoO{sub 4} remains in stable phase under thermal annealing up to 1000?C, whereas it decomposes to ZnO and MoO{sub 3} under transient thermal spike induced by 100?MeV Ag irradiation. The transformation is evidenced by X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Thin films of ZnMoO{sub 4} were synthesized by thermal evaporation and subsequent annealing in oxygen ambient at 600?C for 4?h. XRD results show that as the irradiation fluence increases, the peak related to ZnMoO{sub 4} decreases gradually and eventually disappear, whereas peaks related to ZnO grow steadily up to fluence of 3??10{sup 12} ions/cm{sup 2} and thereafter remain stable till highest fluence. This indicates that polycrystalline ZnMoO{sub 4} film has transformed to polycrystalline ZnO thin film. The Raman lines related to ZnMoO{sub 4} are observed to have disappeared with increasing irradiation fluence. XPS results show modification in bonding and depletion of Mo from near surface region after the ion irradiation. Cross-sectional transmission electron microscopy result shows the formation of ion track of diameter 1216?nm. These results demonstrate that ion beam methods provide the means to control phase splitting of ZnMoO{sub 4} to ZnO and MoO{sub 3} within nanometric dimension along the ion track. The observation of phase splitting and Mo loss are explained in the framework of ion beam induced thermal spike formalism.

Agarwal, D. C.; Avasthi, D. K.; Kabiraj, D. [Inter-University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110067 (India); Varma, S. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Kremer, Felipe; Ridgway, M. C. [Australian National University, Canberra ACT 0200 (Australia)

2014-04-28T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Crystal orientation mechanism of ZnTe epilayers formed on different orientations of sapphire substrates by molecular beam epitaxy  

SciTech Connect (OSTI)

The electrooptic effect in ZnTe has recently attracted research attention, and various device structures using ZnTe have been explored. For application to practical terahertz wave detector devices based on ZnTe thin films, sapphire substrates are preferred because they enable the optical path alignment to be simplified. ZnTe/sapphire heterostructures were focused upon, and ZnTe epilayers were prepared on highly mismatched sapphire substrates by molecular beam epitaxy. Epitaxial relationships between the ZnTe thin films and the sapphire substrates with their various orientations were investigated using an X-ray diffraction pole figure method. (0001) c-plane, (1-102) r-plane, (1-100) m-plane, and (11-20) a-plane oriented sapphire substrates were used in this study. The epitaxial relationship between ZnTe and c-plane sapphire was found to be (111) ZnTe//(0001) sapphire with an in-plane orientation relationship of [?211] ZnTe//[1-100] sapphire. It was found that the (211)-plane ZnTe layer was grown on the m-plane of the sapphire substrates, and the (100)-plane ZnTe layer was grown on the r-plane sapphire. When the sapphire substrates were inclined from the c-plane towards the m-axis direction, the orientation of the ZnTe thin films was then tilted from the (111)-plane to the (211)-plane. The c-plane of the sapphire substrates governs the formation of the (111) ZnTe domain and the ZnTe epilayer orientation. These crystallographic features were also related to the atom arrangements of ZnTe and sapphire.

Nakasu, T., E-mail: n-taizo.nakasu@asagi.waseda.jp; Yamashita, S.; Aiba, T.; Hattori, S.; Sun, W.; Taguri, K.; Kazami, F. [Department of Electrical Engineering and Bioscience, Waseda University, Tokyo 169-8555 (Japan); Kobayashi, M. [Department of Electrical Engineering and Bioscience, Waseda University, Tokyo 169-8555 (Japan); Kagami Memorial Research Institute for Materials and Technology, Waseda University, Tokyo 169-0051 (Japan)

2014-10-28T23:59:59.000Z

162

Residual and nitrogen doping of homoepitaxial nonpolar m-plane ZnO films grown by molecular beam epitaxy  

SciTech Connect (OSTI)

We report the homoepitaxial growth by molecular beam epitaxy of high quality nonpolar m-plane ZnO and ZnO:N films over a large temperature range. The nonintentionally doped ZnO layers exhibit a residual doping as low as {approx}10{sup 14} cm{sup -3}. Despite an effective incorporation of nitrogen, p-type doping was not achieved, ZnO:N films becoming insulating. The high purity of the layers and their low residual n-type doping evidence compensation mechanisms in ZnO:N films.

Taienoff, D.; Deparis, C.; Teisseire, M.; Morhain, C. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); Al-Khalfioui, M.; Vinter, B.; Chauveau, J.-M. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); Universite de Nice Sophia Antipolis, Parc Valrose F-06103 Nice (France)

2011-03-28T23:59:59.000Z

163

Identification of As-vacancy complexes in Zn-diffused GaAs  

SciTech Connect (OSTI)

We have used positron annihilation spectroscopy to study the introduction of point defects in Zn-diffused semi-insulating GaAs. The diffusion was performed by annealing the samples for 2 h at 950 Degree-Sign C. The samples were etched in steps of 7 {mu}m. Both Doppler broadening using slow positron beam and lifetime spectroscopy studies were performed after each etching step. Both techniques showed the existence of vacancy-type defects in a layer of about 45 {mu}m. Secondary ion mass spectroscopy measurements illustrated the presence of Zn at high level in the sample almost up to the same depth. Vacancy-like defects as well as shallow positron traps were observed by lifetime measurements. We distinguish two kinds of defects: As vacancy belongs to defect complex, bound to most likely one Zn atom incorporated on Ga sublattice, and negative-ion-type positron traps. Zn acceptors explained the observation of shallow traps. The effect of Zn was evidenced by probing GaAs samples annealed under similar conditions but without Zn treatment. A defect-free bulk lifetime value is detected in this sample. Moreover, our positron annihilation spectroscopy measurements demonstrate that Zn diffusion in GaAs system is governed by kick-out mechanism.

Elsayed, M. [Department of Physics, Martin Luther University Halle, 06099 Halle (Germany); Department of Physics, Faculty of Science, Minia University, 61519 Minia (Egypt); Krause-Rehberg, R. [Department of Physics, Martin Luther University Halle, 06099 Halle (Germany); Korff, B. [Bremen Center for Computational Materials Science, University Bremen, 28359 Bremen (Germany); Richter, S. [Fraunhofer Center for Silicon Photovoltaics CSP, 06120 Halle (Saale) (Germany); Leipner, H. S. [Center of Materials Science, Martin Luther University Halle, 06099 Halle (Germany)

2013-03-07T23:59:59.000Z

164

Ethanol Steam Reforming on Co/CeO2: The Effect of ZnO Promoter  

SciTech Connect (OSTI)

A series of ZnO promoted Co/CeO2 catalysts were synthesized and characterized using XRD, TEM, H2-TPR, CO chemisorption, O2-TPO, IR-Py, and CO2-TPD. The effects of ZnO on the catalytic performances of Co/CeO2 were studied in ethanol steam reforming. It was found that the addition of ZnO facilitated the oxidation of Co0 via enhanced oxygen mobility of the CeO2 support which decreased the activity of Co/CeO2 in CC bond cleavage of ethanol. 3 wt% ZnO promoted Co/CeO2 exhibited minimum CO and CH4 selectivity and maximum CO2 selectivity. This resulted from the combined effects of the following factors with increasing ZnO loading: (1) enhanced oxygen mobility of CeO2 facilitated the oxidation of CHx and CO to form CO2; (2) increased ZnO coverage on CeO2 surface reduced the interaction between CHx/CO and Co/CeO2; and (3) suppressed CO adsorption on Co0 reduced CO oxidation rate to form CO2. In addition, the addition of ZnO also modified the surface acidity and basicity of CeO2, which consequently affected the C2C4 product distributions.

Davidson, Stephen; Sun, Junming; Wang, Yong

2013-12-02T23:59:59.000Z

165

In situ corrosion analysis of Al-Zn-In-Mg-Ti-Ce sacrificial anode alloy  

SciTech Connect (OSTI)

The corrosion behaviour of Al-5Zn-0.02In-1Mg-0.05Ti-0.5Ce (wt.%) alloy has been investigated by immersion test, scanning electron microscopy, energy dispersive X-ray detector, electrochemical impedance spectroscopy and electrochemical noise. The results show that there exist different corrosion types of the alloy in 3.5% NaCl solution with the immersion time. At the initial stage of immersion, pitting due to the precipitates predominates the corrosion with a typical inductive loop at low frequencies in electrochemical impedance spectroscopy. The major precipitates of the alloy are MgZn{sub 2} and Al{sub 2}CeZn{sub 2} particles. The corrosion potentials of the bulk MgZn{sub 2} and Al{sub 2}CeZn{sub 2} alloys are negative with respect to that of {alpha}-Al, so the MgZn{sub 2} and Al{sub 2}CeZn{sub 2} precipitates can act as activation centre and cause the pitting. In the late corrosion, a relative uniform corrosion predominates the corrosion process controlled by the dissolution/precipitation of the In ions and characterized by a capacitive loop at medium-high frequencies in electrochemical impedance spectroscopy. The potential noise of the pitting shows larger amplitude fluctuation and lower frequency, but the potential noise of the uniform corrosion occurs with smaller amplitude fluctuation and higher frequency.

Ma Jingling, E-mail: majingling.student@sina.com; Wen Jiuba; Zhai Wenxia; Li Quanan

2012-03-15T23:59:59.000Z

166

Low temperature atomic layer deposited ZnO photo thin film transistors  

SciTech Connect (OSTI)

ZnO thin film transistors (TFTs) are fabricated on Si substrates using atomic layer deposition technique. The growth temperature of ZnO channel layers are selected as 80, 100, 120, 130, and 250?C. Material characteristics of ZnO films are examined using x-ray photoelectron spectroscopy and x-ray diffraction methods. Stoichiometry analyses showed that the amount of both oxygen vacancies and interstitial zinc decrease with decreasing growth temperature. Electrical characteristics improve with decreasing growth temperature. Best results are obtained with ZnO channels deposited at 80?C; I{sub on}/I{sub off} ratio is extracted as 7.8 10{sup 9} and subthreshold slope is extracted as 0.116 V/dec. Flexible ZnO TFT devices are also fabricated using films grown at 80?C. I{sub D}V{sub GS} characterization results showed that devices fabricated on different substrates (Si and polyethylene terephthalate) show similar electrical characteristics. Sub-bandgap photo sensing properties of ZnO based TFTs are investigated; it is shown that visible light absorption of ZnO based TFTs can be actively controlled by external gate bias.

Oruc, Feyza B.; Aygun, Levent E.; Donmez, Inci; Biyikli, Necmi; Okyay, Ali K., E-mail: aokyay@ee.bilkent.edu.tr [Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, 06800 Ankara (Turkey); UNAMNational Nanotechnology Research Center, Bilkent University, Bilkent, 06800 Ankara (Turkey); Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, 06800 Ankara (Turkey); Yu, Hyun Yong [The School of Electrical Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

2015-01-01T23:59:59.000Z

167

Effectiveness of three different Zn fertilizers and two methods of application for the control of 'little-leaf' in peach trees in south Texas  

E-Print Network [OSTI]

the Zn soil content. Zinc EDTA at 64. 40 g of Zn / tree was superior to the other soil treatments in increasing foliar Zn and chlorophyll content. However, ZnEDTA was not economicaL The control 2 treatment trees which represented the standard practice...

Arce, Juan Pablo

1991-01-01T23:59:59.000Z

168

Photoelectrochemical performance of DSSC with monodisperse and polydisperse ZnO SPs  

SciTech Connect (OSTI)

Zinc oxide, ZnO, is one of oxide semiconductors being used in DSSC. ZnO is promising material for having fairly higher energy band gap and much higher bulk electron mobility than that of anatase TiO{sub 2}, the most widely used semiconductor for DSSC photoelectrode. This study introduces the synthesis of ZnO by precipitation method. The synthesis involves ZnAc dihydrate and diethylene glycol (DEG) for the chemicals. Various size of ZnO spherical particles (SPs) are obtained in polydisperse and monodisperse particles. Monolayer and bilayer DSSCs are fabricated in sandwich structure and sensitized with N719 dye for 3 and 5 hours. Monolayer DSSC using monodisperse particles (422 nm) is able to generate highest conversion efficiency of 0.569% (V{sub oc} = 541.3 mV, J{sub sc} = 1.92 mA/cm{sup 2}, and fill factor of 54.78%). Bilayer DSSC, i.e. combined 422 - 185 nm ZnO layer, can optimize the photocurrent action spectra in UV regime leading to high conversion efficiency of 0.568 (V{sub oc} = 568.2 mV, J{sub sc} = 2.22 mA/cm{sup 2}, and fill factor of 47.25%). The longer sensitizing time does not always produce better conversion efficiency since it can induce the dissolution of Zn atoms and formation of Zn{sup 2+} - dye resisting the electron transport from dye to ZnO photoelectrode.

Wahyuono, Ruri Agung, E-mail: r-agung-w@ep.its.ac.id; Risanti, Doty D., E-mail: r-agung-w@ep.its.ac.id [Department of Engineering Physics, Institut Teknologi Sepuluh Nopember (Indonesia); Shirosaki, Tomohiro; Nagaoka, Shoji [Kumamoto Industrial Research Institute (Japan); Takafuji, Makoto; Ihara, Hirotaka [Department of Applied Chemistry and Biochemistry, Kumamoto University (Japan)

2014-02-24T23:59:59.000Z

169

Subbarrier fusion of {sup 9}Li with {sup 70}Zn  

SciTech Connect (OSTI)

The cross section for the fusion of {sup 9}Li with {sup 70}Zn was measured for seven projectile energies spanning the subbarrier and near-barrier region (E{sub c.m.} ranging from 9.7 to 13.4 MeV) using the ISAC facility at TRIUMF. {gamma}-ray spectroscopy of the irradiated target foils along with {beta} counting of the chemically separated Ge and As evaporation residues were used to measure the fusion cross sections. Statistical model calculations were used to correct for the yields of any unobserved nuclei. The observed fusion excitation function shows significant subbarrier fusion enhancement with a large deduced value of the fusion radius, R{sub B}=12.1{+-}1.0 fm. Coupled-channels calculations do not account for the observed subbarrier enhancement. The implications of this finding for understanding the fusion of {sup 11}Li are discussed.

Loveland, W.; Vinodkumar, A. M.; Naik, R. S.; Sprunger, P. H.; Matteson, B.; Neeway, J. [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States); Trinczek, M.; Dombsky, M.; Machule, P.; Ottewell, D. [TRIUMF, Vancouver, British Columbia, V6T 2A3 (Canada); Cross, D. [TRIUMF, Vancouver, British Columbia, V6T 2A3 (Canada); Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada); Gagnon, K.; Mills, W. J. [TRIUMF, Vancouver, British Columbia, V6T 2A3 (Canada); Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada)

2006-12-15T23:59:59.000Z

170

Inverse spin Hall effect induced by spin pumping into semiconducting ZnO  

SciTech Connect (OSTI)

The inverse spin Hall effect (ISHE) of n-type semiconductor ZnO thin films with weak spin-orbit coupling has been observed by utilizing the spin pumping method. In the ferromagnetic resonance condition, the spin pumping driven by the dynamical exchange interaction of a permalloy film injects a pure spin current into the adjacent ZnO layer. This spin current gives rise to a DC voltage through the ISHE in the ZnO layer, and the DC voltage is proportional to the microwave excitation power. The effect is sizeable even when the spin backflow is considered.

Lee, Jung-Chuan [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Huang, Leng-Wei [Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan (China); Hung, Dung-Shing, E-mail: dshung@mail.mcu.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Department of Information and Telecommunications Engineering, Ming Chuan University, Taipei 111, Taiwan (China); Chiang, Tung-Han [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Huang, J. C. A., E-mail: jcahuang@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Liang, Jun-Zhi [Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Physics, Fu Jen Catholic University, Taipei 242, Taiwan (China); Lee, Shang-Fan, E-mail: leesf@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan (China)

2014-02-03T23:59:59.000Z

171

Phosphorescence quenching by mechanical stimulus in CaZnOS:Cu  

SciTech Connect (OSTI)

We have found that phosphorescence intensity of CaZnOS:Cu decreased visibly under an applied load. This mechanical quenching (MQ) of phosphorescence in CaZnOS:Cu corresponded to the mechanical stimuli. We have thus demonstrated that the MQ of CaZnOS:Cu could be used for visualizing stress distributions in practical applications. We propose that MQ arises from non-radiative recombination due to electron-transfer from trap levels to non-radiative centers as a result of the mechanical load.

Tu, Dong; Kamimura, Sunao [National Institute of Advanced Industrial Science and Technology (AIST), Saga 841-0052 (Japan); Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580 (Japan); Xu, Chao-Nan, E-mail: cn-xu@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), Saga 841-0052 (Japan); Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580 (Japan); International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Fujio, Yuki; Sakata, Yoshitaro [National Institute of Advanced Industrial Science and Technology (AIST), Saga 841-0052 (Japan); Ueno, Naohiro [National Institute of Advanced Industrial Science and Technology (AIST), Saga 841-0052 (Japan); Graduate School of Science and Engineering, Saga University, Saga 840-8502 (Japan)

2014-07-07T23:59:59.000Z

172

Nonlinear optical properties of ZnO/poly (vinyl alcohol) nanocomposite films  

SciTech Connect (OSTI)

Extensive studies have already been reported on the optical characteristics of ZnO/polymer nanocomposite films, using a variety of polymers including transparent polymers such as polystyrene, polymethyl methacrylate etc and many interesting results have been established regarding the non linear optical characteristics of these systems. Poly (vinyl alcohol)(PVA) is a water soluble polymer. Though the structural and optical studies of ZnO/PVA nanocomposite films have already been investigated, there are no detailed reports on the nonlinear optical characteristics of ZnO/PVA nanocomposite films, irrespective of the fact that these nanocomposite films can be synthesized using quite easy and cost effective methods. The present work is an attempt to study in detail the nonlinear optical behaviour of ZnO/PVA nanocomposite films using Z-scan technique. Highly transparent ZnO/PVA nanocomposite films were prepared from the ZnO incorporated PVA solution in water using spin coating technique. The ZnO nanoparticles were synthesized by the simple chemical route at room temperature. High-resolution transmission electron microscopy studies show that the ZnO nanoparticles are of size around 10 nm. The ZnO/PVA nanocomposite films were structurally characterized by X-ray diffraction technique, from which the presence of both PVA and ZnO in the nanocomposite was established. The optical absorptive nonlinearity in the nanocomposite films was investigated using open aperture Z-scan technique. The results indicate optical limiting type nonlinearity in the films due to two photon absorption in ZnO with efficiency more than 50%. These films also show a self defocusing type negative nonlinear refraction in closed aperture Z-scan experiment. The present studies indicate that, highly transparent and homogeneous films of ZnO/PVA nanocomposite can be obtained on glass substrates using simple methods, in a highly cost effective way, since PVA is water soluble. These nanocomposite films offer prospects of application as efficient optical limiters to protect light sensitive devices from the possible damage on exposure to high intensity radiation.

Jeeju, P. P., E-mail: jeejupp@gmail.com [Department of Physics, S N M College, Maliankara, Ernakulam, Kerala (India); Jayalekshmi, S., E-mail: jayalekshmi@cusat.ac.in [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi 682 022 (India); Chandrasekharan, K. [Department of Physics, National Institute of Technology, Calicut, Kerala (India)

2014-01-28T23:59:59.000Z

173

ZnO/porous-Si and TiO{sub 2}/porous-Si nanocomposite nanopillars  

SciTech Connect (OSTI)

Porous Si nanopillar arrays are used as templates for atomic layer deposition of ZnO and TiO{sub 2}, and thus, ZnO/porous-Si and TiO{sub 2}/porous-Si nanocomposite nanopillars are fabricated. The diffusion of the precursor molecules into the inside of the porous structure occurs via Knudsen diffusion and is strongly limited by the small pore size. The luminescence of the ZnO/porous-Si nanocomposite nanopillars is also investigated, and the optical emission can be changed and even quenched after a strong plasma treatment. Such nanocomposite nanopillars are interesting for photocatalysis and sensors.

Wang, Dong, E-mail: dong.wang@tu-ilmenau.de; Yan, Yong; Schaaf, Peter [Chair Materials for Electronics, Institute of Materials Engineering and Institute of Micro- and Nanotechnologies MacroNano, TU Ilmenau, Gustav-Kirchhoff-Str. 5, 98693 Ilmenau (Germany); Sharp, Thomas [Oxford Instruments Plasma Technology Ltd., Yatton, Bristol BS49 4AP (United Kingdom); Schnherr, Sven; Ronning, Carsten [Institute for Solid State Physics, Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Ji, Ran [SUSS MicroTec Lithography GmbH, Schleissheimer Str. 90, 85748 Garching (Germany)

2015-01-01T23:59:59.000Z

174

Evaluation of Melt-Grown, ZnO Single Crystals for Use as Alpha-Particle Detectors  

SciTech Connect (OSTI)

As part of an ongoing investigation of the scintillation properties of zinc-oxide-based scintillators, several melt-grown, ZnO single crystals have been characterized using -particle excitation, infrared reflectance, and room temperature photoluminescence. The crystals, grown by Cermet, Inc. using a pressurized melt growth process, were doped with Group 1 elements (Li), Group 2 elements (Mg), Group 3 elements (Ga, In) and Lanthanides (Gd, Er, Tm). The goals of these studies are to better understand the scintillation mechanisms associated with various members of the ZnO scintillator family and to then use this knowledge to improve the radiation detection capabilities of ZnO-based scintillators. One application for which ZnO is particularly well suited as a scintillator is as the associated particle detector in a deuterium-tritium (D-T) neutron generator. Application requirements include the exclusion of organic materials, outstanding timing resolution, and high radiation resistance. ZnO(Ga) and ZnO(In) have demonstrated fast (sub-nanosecond) decay times with relatively low light yields, and ZnO(Ga) has been used in a powder form as the associated particle detector for a D-T neutron generator. Four promising candidate materials, ZnO, ZnO:Ga, ZnO:In,Li, and ZnO:Er,Li, were identified in this study. These four samples demonstrated sub-nanosecond decay times and alpha particle excited luminescence comparable to BC-400 fast plastic scintillator. The ZnO:Mg,Ga, ZnO:Gd, and ZnO:Li samples demonstrated appreciable slow (microsecond) decay components that would be incompatible with high-counting-rate applications.

Neal, John S [ORNL; Giles, N. C. [West Virginia University; Yang, Xiaocheng [West Virginia University; Wall, R. Andrew [Wake Forest University, Winston-Salem, NC; Ucer, Burak [Wake Forest University, Winston-Salem, NC; Williams, Richard T. [Wake Forest University, Winston-Salem, NC; Wisniewski, Dariusz J [ORNL; Boatner, Lynn A [ORNL; Rengarajan, Varatharajan [ORNL; Nause, Jeff E [ORNL; Nemeth, Bell [Cermet, Inc., Atlanta

2008-01-01T23:59:59.000Z

175

Measurements of sputtered neutrals and ions and investigation of their roles on the plasma properties during rf magnetron sputtering of Zn and ZnO targets  

SciTech Connect (OSTI)

Langmuir probe and optical absorption spectroscopy measurements were used to determine the line-integrated electron density, electron temperature, and number density of Ar atoms in metastable {sup 3}P{sub 2} and {sup 3}P{sub 0} levels in a 5 mTorr, rf magnetron sputtering plasmas used for the deposition of ZnO-based thin films. While the average electron energy and density of Ar atoms in {sup 3}P{sub 2} and {sup 3}P{sub 0} excited states were fairly independent of self-bias voltage, the Ar {sup 3}P{sub 2}-to-electron number density ratio decreased by approximately a factor of 5 when going from ?115 V to ?300 V. This decrease was correlated to an increase by about one order of magnitude of the number density of sputtered Zn atoms determined by absolute actinometry measurements on Zn I using either Ar or Xe as the actinometer gas. These results were also found to be in excellent agreement with the predictions of a global model accounting for Penning ionization of sputtered Zn particles. The importance of the latter reactions was further confirmed by plasma sampling mass spectrometry showing a double peak structure for Zn ions: a low-energy component ascribed to thermalized ions created in the gas phase (by direct electron impact and by Penning ionization) and a high-energy tail due to ions ejected from the target and reaching quasi-collisionlessly the substrate surface.

Maaloul, L.; Stafford, L. [Dpartement de Physique, Universit de Montral, Montral, Qubec H3C 3J7 (Canada)] [Dpartement de Physique, Universit de Montral, Montral, Qubec H3C 3J7 (Canada)

2013-11-15T23:59:59.000Z

176

Efficient light emitting devices utilizing CdSe(ZnS) quantum dots in organic host matrices  

E-Print Network [OSTI]

We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the ...

Coe-Sullivan, Seth (Seth Alexander)

2002-01-01T23:59:59.000Z

177

PROCESS DEVELOPMENT FOR ZnO-BASED DEVICES KELLY PUI SZE IP  

E-Print Network [OSTI]

PROCESS DEVELOPMENT FOR ZnO-BASED DEVICES By KELLY PUI SZE IP A DISSERTATION PRESENTED OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2005 #12;Copyright 2005 by Kelly Pui Sze Ip #12;To my family

Pearton, Stephen J.

178

Spinel ferrite nanocrystals embedded inside ZnO: magnetic, electronic and magneto-transport properties  

E-Print Network [OSTI]

Spinel ferrite nanocrystals embedded inside ZnO: magnetic,paper we show that spinel ferrite nanocrystals (NiFe 2 O 4 ,annealing. The two kinds of ferrites show di?erent magnetic

Zhou, Shengqiang

2010-01-01T23:59:59.000Z

179

Polymeric precursor derived nanocrystalline ZnO thin films using EDTA as chelating agent  

E-Print Network [OSTI]

properties, ZnO has plausible electro-optical applications, such as, solar cells [1, 2], light- emitting diodes [3, 4], UV lasers [5], thin film transistors [6,7], and UV photodetectors [8]. Besides

Mohanty, Saraju P.

180

Si, CdTe and CdZnTe radiation detectors for imaging applications.  

E-Print Network [OSTI]

??The structure and operation of CdTe, CdZnTe and Si pixel detectors based on crystalline semiconductors, bump bonding and CMOS technology and developed mainly at Oy (more)

Schulman, Tom

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Development of ZnO Based Light Emitting Diodes and Laser Diodes.  

E-Print Network [OSTI]

??ZnO based homojunction light emitting diode, double heterojunction light emitting diode, embedded heterojunction random laser diode and Fabry-Perot nanowire laser devices were fabricated and characterized. (more)

Kong, Jieying

2012-01-01T23:59:59.000Z

182

ZnO PN Junctions for Highly-Efficient, Low-Cost Light Emitting Diodes  

SciTech Connect (OSTI)

By 2015, the US Department of Energy has set as a goal the development of advanced solid state lighting technologies that are more energy efficient, longer lasting, and more cost-effective than current technology. One approach that is most attractive is to utilize light-emitting diode technologies. Although III-V compound semiconductors have been the primary focus in pursuing this objective, ZnO-based materials present some distinct advantages that could yield success in meeting this objective. As with the nitrides, ZnO is a direct bandgap semiconductor whose gap energy (3.2 eV) can be tuned from 3.0 to 4 eV with substitution of Mg for higher bandgap, Cd for lower bandgap. ZnO has an exciton binding energy of 60 meV, which is larger than that for the nitrides, indicating that it should be a superior light emitting semiconductor. Furthermore, ZnO thin films can be deposited at temperatures on the order of 400-600 C, which is significantly lower than that for the nitrides and should lead to lower manufacturing costs. It has also been demonstrated that functional ZnO electronic devices can be fabricated on inexpensive substrates, such as glass. Therefore, for the large-area photonic application of solid state lighting, ZnO holds unique potential. A significant impediment to exploiting ZnO in light-emitting applications has been the absence of effective p-type carrier doping. However, the recent realization of acceptor-doped ZnO material overcomes this impediment, opening the door to ZnO light emitting diode development In this project, the synthesis and properties of ZnO-based pn junctions for light emitting diodes was investigated. The focus was on three issues most pertinent to realizing a ZnO-based solid state lighting technology, namely (1) achieving high p-type carrier concentrations in epitaxial and polycrystalline films, (2) realizing band edge emission from pn homojunctions, and (3) investigating pn heterojunction constructs that should yield efficient light emission. The project engaged established expertise at the University of Florida in ZnO film growth (D. Norton), device fabrication (F. Ren) and wide bandgap photonics (S. Pearton). It addressed p-type doping and junction formation in (Zn,Mg)O alloy thin films. The project employed pulsed laser deposition for film growth. The p-type dopant of interest was primarily phosphorus, given the recent results in our laboratory and elsewhere that this anions can yield p-type ZnO-based materials. The role of Zn interstitials, oxygen vacancies, and/or hydrogen complexes in forming compensating shallow donor levels imposes the need to simultaneously consider the role of in situ and post-growth processing conditions. Temperature-dependent Hall, Seebeck, C-V, and resistivity measurements was used to determine conduction mechanisms, carrier type, and doping. Temperature-dependent photoluminescence was used to determine the location of the acceptor level, injection efficiency, and optical properties of the structures. X-ray diffraction will used to characterize film crystallinity. Using these materials, the fabrication and characterization of (Zn,Mg)O pn homojunction and heterojunction devices was pursued. Electrical characterization of the junction capacitance and I-V behavior was used to extract junction profile and minority carrier lifetime. Electroluminescence from biased junctions was the primary property of interest.

David P. Norton; Stephen Pearton; Fan Ren

2007-09-30T23:59:59.000Z

183

Luminescence and electrical properties of single ZnO/MgO core/shell nanowires  

SciTech Connect (OSTI)

To neutralise the influence of the surface of ZnO nanowires for photonics and optoelectronic applications, we have covered them with insulating MgO film and individually contacted them for electrical characterisation. We show that such a metal-insulator-semiconductor-type nanodevice exhibits a high diode ideality factor of 3.4 below 1?V. MgO shell passivates ZnO surface states and provides confining barriers to electrons and holes within the ZnO core, favouring excitonic ultraviolet radiative recombination, while suppressing defect-related luminescence in the visible and improving electrical conductivity. The results indicate the potential use of ZnO/MgO nanowires as a convenient building block for nano-optoelectronic devices.

Grinblat, Gustavo; Comedi, David [Laboratorio de Fsica del Slido, Dep. de Fsica, FACET, Universidad Nacional de Tucumn, Tucumn, and Consejo Nacional de Investigaciones Cientficas y Tcnicas (CONICET) (Argentina)] [Laboratorio de Fsica del Slido, Dep. de Fsica, FACET, Universidad Nacional de Tucumn, Tucumn, and Consejo Nacional de Investigaciones Cientficas y Tcnicas (CONICET) (Argentina); Bern, Francis; Barzola-Quiquia, Jos; Esquinazi, Pablo, E-mail: esquin@physik.uni-leipzig.de [Division of Superconductivity and Magnetism, Institute for Experimental Physics II, University of Leipzig, D-04103 Leipzig (Germany)] [Division of Superconductivity and Magnetism, Institute for Experimental Physics II, University of Leipzig, D-04103 Leipzig (Germany); Tirado, Mnica [Laboratorio de Nanomateriales y Propiedades Dielctricas, Dep. de Fsica, FACET, Universidad Nacional de Tucumn, Tucumn (Argentina)] [Laboratorio de Nanomateriales y Propiedades Dielctricas, Dep. de Fsica, FACET, Universidad Nacional de Tucumn, Tucumn (Argentina)

2014-03-10T23:59:59.000Z

184

Band offsets for mismatched interfaces: The special case of ZnO...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Abstract: High-quality planar interfaces between ZnO and CdTe would be useful in optoelectronic applications, but appear difficult to achieve given the rather different crystal...

185

Photo-driven autonomous hydrogen generation system based on hierarchically shelled ZnO nanostructures  

SciTech Connect (OSTI)

A quantum dot semiconductor sensitized hierarchically shelled one-dimensional ZnO nanostructure has been applied as a quasi-artificial leaf for hydrogen generation. The optimized ZnO nanostructure consists of one dimensional nanowire as a core and two-dimensional nanosheet on the nanowire surface. Furthermore, the quantum dot semiconductors deposited on the ZnO nanostructures provide visible light harvesting properties. To realize the artificial leaf, we applied the ZnO based nanostructure as a photoelectrode with non-wired Z-scheme system. The demonstrated un-assisted photoelectrochemical system showed the hydrogen generation properties under 1 sun condition irradiation. In addition, the quantum dot modified photoelectrode showed 2 mA/cm{sup 2} current density at the un-assisted condition.

Kim, Heejin; Yong, Kijung [Surface Chemistry Laboratory of Electronic Materials, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)] [Surface Chemistry Laboratory of Electronic Materials, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)

2013-11-25T23:59:59.000Z

186

Zn3P2 and Cu2O substrates for solar energy conversion.  

E-Print Network [OSTI]

??Zinc phosphide (Zn3P2) and cuprous oxide (Cu2O) are promising and earth-abundant alternatives to traditional thin film photovoltaics materials such as CIGS, CdTe, and a-Si. We (more)

Kimball, Gregory Michael

2012-01-01T23:59:59.000Z

187

Metalorganic chemical vapor deposition of carbon-free ZnO using...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Metalorganic chemical vapor deposition of carbon-free ZnO using the bis(2,2,6,6-tetramethyl-3,5-heptanedionato)zinc precursor. Metalorganic chemical vapor deposition of carbon-free...

188

Optimizing the Power Output of a ZnO Photocell by Piezopotential  

E-Print Network [OSTI]

properties of ZnO make it an ideal choice for applications in nanogenerators10 13 for converting mechanical together with the thermionic emission theory has explained the four kinds of relationships observed

Wang, Zhong L.

189

Donor bound excitons in ZnSe nanoresonators - Applications in quantum information science  

SciTech Connect (OSTI)

Here we summarize the advantages of excitons bound to isolated fluorine donor in ZnSe/ZnMgSe quantum well nano-structures. Devices based on these semiconductors, are particularly suited to implement concepts of the optical manipulation of quantum states in solid-state material. The fluorine donor in ZnSe provides a physical qubit with potential advantages over previously researched qubits. In this context we show several initial demonstrations of devices, such as a low-threshold microdisk laser and an indistinguishable single photon source. Additionally we demonstrate the realization of a controllable three-level-system qubit consisting of a single Fluorine donor in a ZnSe nano-pillar, which provides an optical accessible single electon spin qubit.

Pawlis, A. [Department of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn, Germany and Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088 (United States); Lischka, K. [Department of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn (Germany); Sanaka, K.; Yamamoto, Y. [Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088, USA and National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430 (Japan); Sleiter, D. [Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088 (United States)

2014-05-15T23:59:59.000Z

190

Determination of the spontaneous polarization of wurtzite (Mg,Zn)O  

SciTech Connect (OSTI)

We report on the experimental determination of the spontaneous polarization of wurtzite-(Mg,Zn)O by examination of the recombination dynamics of polar ZnO/(Mg,Zn)O quantum wells (QWs). The thickness-dependent decay time of the unscreened single-exciton states inside the QWs was modeled by a self-consistent solution of Schrdinger- and Poisson-equation to deduce the total polarization across the QW for different Mg-contents inside the barriers. By the separation of the piezoelectric components of the polarization, a linear increase in spontaneous polarization with increasing Mg-content x of P/x?=?(0.151??0.015) C/m{sup 2} was determined for Mg{sub x} Zn{sub 1?x} O.

Stlzel, Marko, E-mail: stoelzel@physik.uni-leipzig.de; Mller, Alexander; Benndorf, Gabriele; Lorenz, Michael; Grundmann, Marius [Institut fr Experimentelle Physik II, Universitt Leipzig, Linnstr. 5, 04103 Leipzig (Germany); Patzig, Christian; Hche, Thomas [Fraunhofer Institute for Mechanics of Materials IWM, Center for Applied Microstructure Diagnostics, Walter-Huelse-Strae 1, 06120 Halle (Saale) (Germany)

2014-05-12T23:59:59.000Z

191

Nitrogen-Doped ZnO Nanowire Arrays for Photoelectrochemical Water Splitting  

E-Print Network [OSTI]

fuel of the future.1-3 However, currently the main production of hydrogen comes from steam reforming in ammonia to incorporate N as a dopant. Nanowires with a controlled N concentration (atomic ratio of N to Zn

Li, Yat

192

Thermal conductivity of self-assembled nano-structured ZnO bulk ceramics  

SciTech Connect (OSTI)

In this study, we describe the changes in thermal conductivity behavior of ZnO-Al micro- and nano-two-phase self-assembled composites with varying grain sizes. The reduction in thermal conductivity values of micro-composites was limited to {approx}15% for ZnO-4% Al. However, nano-composites exhibited large reduction, by a factor of about three, due to uniform distribution of nano-precipitates (ZnAl2O4) and large grain boundary area. Interestingly, the micro-composites revealed continuous decrease in thermal conductivity with increase in Al substitution while the nano-composites exhibited the lowest magnitudes for 2% Al concentration. Raman spectra indicated that phonon confinement in ZnO-Al nano-composites causes drastic decrease in the value of thermal conductivity.

Zhao, Yu [Bio-Inspired Materials and Devices Laboraory (BMDL); Yan, Yongke [Bio-Inspired Materials and Devices Laboraory (BMDL); Kumar, Ashok [Bio-Inspired Materials and Devices Laboraory (BMDL); Wang, Hsin [ORNL; Porter, Wallace D [ORNL

2012-01-01T23:59:59.000Z

193

Residue Ionization in LpxC Directly Observed by 67Zn NMR Spectroscopy...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Abstract: The pH dependence of the 67Zn NMR spectroscopy has been measured for both wild type (WT) and the H265A mutant of LpxC, each in the resting state absence of...

194

Synthesis of ZnO decorated graphene nanocomposite for enhanced photocatalytic properties  

SciTech Connect (OSTI)

Zinc oxide/Graphene (GZ) composites with different concentrations of ZnO were successfully synthesized through simple chemical precipitation method. The X-ray diffraction pattern and the micro-Raman spectroscopic technique revealed the formation of GZ composite, and the energy dispersive X-ray spectrometry analysis showed the purity of the prepared samples. The ZnO nanoparticles decorated graphene sheets were clearly visible in the field emission scanning electron micrograph. Raman mapping was employed to analyze the homogeneity of the prepared samples. The diffuse-reflectance spectra clearly indicated that the formation of GZ composites promoted the absorption in the visible region also. The photocatalytic activity of ZnO and GZ composites was studied by the photodegradation of Methylene blue dye. The results revealed that the GZ composites exhibited a higher photocatalytic activity than pristine ZnO. Hence, we proposed a simple wet chemical method to synthesize GZ composite and its application on photocatalysis was demonstrated.

Gayathri, S.; Jayabal, P. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021, Tamilnadu (India); Kottaisamy, M. [Department of Chemistry, Thiagarajar College of Engineering, Madurai 625014, Tamilnadu (India); Ramakrishnan, V., E-mail: vr.optics1@gmail.com [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021, Tamilnadu (India); Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram 695016, Kerala (India)

2014-05-07T23:59:59.000Z

195

Multianalyte biosensor based on pH-sensitive ZnO electrolyteinsulatorsemiconductor structures  

SciTech Connect (OSTI)

Multianalyte electrolyteinsulatorsemiconductor (EIS) sensors with a ZnO sensing membrane annealed on silicon substrate for use in pH sensing were fabricated. Material analyses were conducted using X-ray diffraction and atomic force microscopy to identify optimal treatment conditions. Sensing performance for various ions of Na{sup +}, K{sup +}, urea, and glucose was also tested. Results indicate that an EIS sensor with a ZnO membrane annealed at 600?C exhibited good performance with high sensitivity and a low drift rate compared with all other reported ZnO-based pH sensors. Furthermore, based on well-established pH sensing properties, pH-ion-sensitive field-effect transistor sensors have also been developed for use in detecting urea and glucose ions. ZnO-based EIS sensors show promise for future industrial biosensing applications.

Haur Kao, Chyuan; Chun Liu, Che; Ueng, Herng-Yih [Department of Electronic Engineering, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Chen, Hsiang, E-mail: hchen@ncnu.edu.tw; Cheng Chu, Yu; Jie Chen, Yu [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Puli, Nantou 545, Taiwan (China); Ling Lee, Ming; Ming Chang, Kow [Department of Electronic Engineering, National Chiao Tung University, Hsin-Chu 300, Taiwan (China)

2014-05-14T23:59:59.000Z

196

The Effect of Zn Addition on the Oxidation State of Cobalt in...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The effect of Zn promotion on the activity and selectivity of CoZrO2 catalysts for ethanol steam reforming was investigated. The catalysts were synthesized by incipient wetness...

197

Thin-film polycrystalline n-ZnO/p-CuO heterojunction  

SciTech Connect (OSTI)

Results of X-ray diffraction and spectral-optical studies of n-ZnO and p-CuO films deposited by gas-discharge sputtering with subsequent annealing are presented. It is shown that, despite the difference in the crystal systems, the polycrystallinity of n-ZnO and p-CuO films enables fabrication of a heterojunction from this pair of materials.

Lisitski, O. L.; Kumekov, M. E.; Kumekov, S. E. [Satpaev Kazakh National Technical University (Kazakhstan)], E-mail: skumekov@mail.ru; Terukov, E. I. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

2009-06-15T23:59:59.000Z

198

Electron transfer and capture dynamics in ZnSe quantum wells grown on GaAs  

SciTech Connect (OSTI)

We investigate the transfer and capture dynamics of electrons in phase coherent photorefractive ZnSe quantum wells grown on GaAs using degenerate three-beam four-wave-mixing. The measurements reveal electron capture times by the quantum well in the order of several tens of picoseconds and a transit time of approximately 5 picoseconds from the GaAs substrate through the ZnMgSe barrier.

Dongol, A.; Wagner, H. P. [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States)

2013-12-04T23:59:59.000Z

199

A mathematical model of a Zn/Br? cell on charge  

E-Print Network [OSTI]

to the Continuous Model for the Copper Electrowinning Example Vll. Demonstration that the Effective Separator Thickness is an Independent Parameter Vill. Comparison of' the One Step to the Continuous Model for the Zn 'Brs Cell 6 o 70 IX. Current Densities... Subject: Chemical Engineering A MATHEMATICAL MODEL OF A ZN, 'BR, CELL ON CHARGE A Thesi bt MICHAEL JOSEPH MADER Approved as to style and content by: Ralph E. 6'hite (Chairman of Committee) Charles lover Bart Childs (Mentber) Charles D. H lland...

Mader, Michael Joseph

2012-06-07T23:59:59.000Z

200

Mechanical and transparent conductive properties of ZnO and Ga-doped ZnO films sputtered using electron-cyclotron-resonance plasma on polyethylene naphtalate substrates  

SciTech Connect (OSTI)

Transparent conductive ZnO and Ga-doped ZnO (GZO) films were deposited on polyethylene naphtalate (PEN) sheet substrates using electron cyclotron resonance plasma sputtering. Both ZnO and GZO films were highly adhesive to the PEN substrates without inserting an intermediate layer in the interface. When compared at the same thickness, the transparent conductive properties of GZO films on PEN substrates were only slightly inferior to those on glass substrates. However, the carrier concentration of ZnO films on PEN substrates was 1.5?times that of those on glass substrates, whereas their Hall mobility was only 60% at a thickness of 300?nm. The depth profile of elements measured by secondary ion mass spectroscopy revealed the diffusion of hydrocarbons out of the PEN substrate into the ZnO film. Hence, doped carbons may act as donors to enhance carrier concentration, and the intermixing of elements at the interface may deteriorate the crystallinity, resulting in the lower Hall mobility. When the ZnO films were thicker than 400?nm, cracks became prevalent because of the lattice mismatch strain between the film and the substrate, whereas GZO films were free of cracks. The authors investigated how rolling the films around a cylindrical pipe surface affected their conductive properties. Degraded conductivity occurred at a threshold pipe radius of 10?mm when tensile stress was applied to the film, but it occurred at a pipe radius of 5?mm when compressive stress was applied. These values are guidelines for bending actual devices fabricated on PEN substrates.

Akazawa, Housei, E-mail: akazawa.housei@lab.ntt.co.jp [NTT Microsystem Integration Laboratories 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

2014-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Morphological and electrochemical characterization of electrodeposited ZnAg nanoparticle composite coatings  

SciTech Connect (OSTI)

Silver nanoparticles with an average size of 23 nm were chemically synthesized and used to fabricate ZnAg composite coatings. The ZnAg composite coatings were generated by electrodeposition method using a simple sulfate plating bath dispersed with 0.5, 1 and 1.5 g/l of Ag nanoparticles. Scanning electron microscopy, X-ray diffraction and texture co-efficient calculations revealed that Ag nanoparticles appreciably influenced the morphology, micro-structure and texture of the deposit. It was also noticed that agglomerates of Ag nanoparticles, in the case of high bath load conditions, produced defects and dislocations on the deposit surface. Ag nanoparticles altered the corrosion resistance property of ZnAg composite coatings as observed from Tafel polarization, electrochemical impedance analysis and an immersion test. Reduction in corrosion rate with increased charge transfer resistance was observed for ZnAg composite coatings when compared to a pure Zn coating. However, the particle concentration in the plating bath and their agglomeration state directly influenced the surface morphology and the subsequent corrosion behavior of the deposits. - Highlights: Synthesis of Ag nanoparticles with an average size of 23 nm Fabrication of Zn/nano Ag composite coating on mild steel Composite coatings showed better corrosion resistance. Optimization of particle concentration is necessary.

Punith Kumar, M.K.; Srivastava, Chandan, E-mail: csrivastava@materials.iisc.ernet.in

2013-11-15T23:59:59.000Z

202

Magnetic properties and loss separation in iron-silicone-MnZn ferrite soft magnetic composites  

SciTech Connect (OSTI)

This paper investigates the magnetic and structural properties of iron-based soft magnetic composites coated with silicone-MnZn ferrite hybrid. The organic silicone resin was added to improve the flexibility of the insulated iron powder and causes better adhesion between particles to increase the mechanical properties. Scanning electron microscopy and distribution maps show that the iron particle surface is covered with a thin layer of silicone-MnZn ferrite. Silicone-MnZn ferrite coated samples have higher permeability when compared with the non-magnetic silicone resin coated compacts. The real part of permeability increases by 34.18% when compared with the silicone resin coated samples at 20 kHz. In this work, a formula for calculating the total loss component by loss separation method is presented and finally the different parts of total losses are calculated. The results show that the eddy current loss coefficient is close to each other for the silicone-MnZn ferrite, silicone resin and MnZn ferrite coated samples (0.0078Zn ferrite coated sample (k{sub 2} =1.4058) in comparison with other samples.

Wu, Shen; Sun, Aizhi; Xu, Wenhuan; Zou, Chao; Yang, Jun; Dong, Juan [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China)

2013-12-16T23:59:59.000Z

203

Sensing performances of ZnO nanostructures grown under different oxygen pressures to hydrogen  

SciTech Connect (OSTI)

Graphical abstract: Display Omitted Highlights: ? Surface morphology depends on the oxygen pressure. ? Structural degradation was observed for the ZnO samples when oxygen pressure was overhigh. ? The sensitivity of the ZnO-based sensors increase with grown oxygen pressure. -- Abstract: For extensive use in an industrialized process of individual ZnO nanostructures applied in gas sensors, a simple, inexpensive, and safe synthesis process is required. Here, nanostructured ZnO films were grown by a pulsed laser deposition technique under different oxygen pressures. Scanning electron microscopy images show nanopores, nanotips, and nanoparticles are obtained and energy dispersive X-ray spectroscopy data indicate oxygen concentration of the synthesized samples increases monotonously with oxygen pressure. The sensor based on ZnO with high oxygen concentration has high sensitivity, rapid response (9 s) and recovery (80 s) behavior to 500 ppm hydrogen below 150 C. Experimental data indicate that high oxygen concentration effectively improves the sensing properties of nanostructured ZnO.

Chu, Jin; Peng, Xiaoyan [Department of Physics, University of Puerto Rico Rio Piedras, San Juan, 00936-8377 PR (United States)] [Department of Physics, University of Puerto Rico Rio Piedras, San Juan, 00936-8377 PR (United States); Wang, Zhenbo [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China)] [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Feng, Peter, E-mail: P.feng@upr.edu [Department of Physics, University of Puerto Rico Rio Piedras, San Juan, 00936-8377 PR (United States)] [Department of Physics, University of Puerto Rico Rio Piedras, San Juan, 00936-8377 PR (United States)

2012-12-15T23:59:59.000Z

204

Magneto acoustical emission in nanocrystalline MnZn ferrites  

SciTech Connect (OSTI)

Graphical abstract: Mn{sub 0.4}Zn{sub 0.6}Fe{sub 2}O{sub 4} powders were prepared by microwave hydrothermal method. The powders were characterized by X-ray diffraction, transmission electron microscope. The powders were sintered at different temperatures 400, 500, 600, 700, 800 and 900 C/30 min using microwave sintering method. The grain size was estimated by scanning electron microscope. The room temperature dielectric and magnetic properties were studied in the frequency range (100 kHz1.8 GHz). The magnetization properties were measured upto 1.5 T. The acoustic emission has been measured along the hysteresis loops from 80 K to Curie temperature. It is found that the magneto-acoustic emission (MAE) activity along hysteresis loop is proportional to the hysteresis losses during the same loop. This law has been verified on series of polycrystalline ferrites and found that the law is valid whatever the composition, the grain size and temperature. It is also found that the domain wall creation/or annihilation processes are the origin of the MAE. - Highlights: The AE been measured along the hysteresis loops from 80 K to Curie temperature. The MAE activity along hysteresis loop is proportional to P{sub h} during the same loop. It is found that the domain wall creation/or annihilation processes are the origin of the MAE. - Abstract: Mn{sub 0.4}Zn{sub 0.6}Fe{sub 2}O{sub 4} powders were prepared by microwave hydrothermal method. The powders were characterized by X-ray diffraction, transmission electron microscope. The powders were sintered at different temperatures 400, 500, 600, 700, 800 and 900 C/30 min using microwave sintering method. The grain size was estimated by scanning electron microscope. The room temperature dielectric and magnetic properties were studied in the frequency range (100 kHz1.8 GHz). The magnetization properties were measured upto 1.5 T. The acoustic emission has been measured along the hysteresis loops from 80 K to Curie temperature. It is found that the magneto-acoustic emission (MAE) activity along hysteresis loop is proportional to the hysteresis losses during the same loop. This law has been verified on series of polycrystalline ferrites and found that the law is valid whatever the composition, the grain size and temperature. It is also found that the domain wall creation/or annihilation processes are the origin of the MAE.

Praveena, K., E-mail: praveenaou@gmail.com [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Department of Physics, Osmania University, Hyderabad 500007 (India); Murthty, S.R. [Department of Physics, Osmania University, Hyderabad 500007 (India)

2013-11-15T23:59:59.000Z

205

ZnO-Al2O3 and ZnO-TiO2 Core-Shell Nanowire Dye-Sensitized Solar Cells Matt Law,, Lori E. Greene,, Aleksandra Radenovic, Tevye Kuykendall,,  

E-Print Network [OSTI]

ZnO-Al2O3 and ZnO-TiO2 Core-Shell Nanowire Dye-Sensitized Solar Cells Matt Law,,§ Lori E. Greene the construction and performance of dye-sensitized solar cells (DSCs) based on arrays of ZnO nanowires coated loadings through an increase in nanowire array surface area. Introduction Dye-sensitized solar cells (DSCs

Yang, Peidong

206

In vitro cytotoxicity tests of ZnO?Bi{sub 2}O{sub 3}?Mn{sub 2}O{sub 3}-based varistor fabricated from ZnO micro and nanoparticle powders on L929 mouse cells  

SciTech Connect (OSTI)

The present study investigated the cytotoxicity of ZnO?Bi{sub 2}O{sub 3}?Mn{sub 2}O{sub 3}-varistors. To this effect, ZnO?Bi{sub 2}O{sub 3}?Mn{sub 2}O{sub 3} varistors fabricated from ZnO micro-and nanoparticle powders are prepared via conventional ceramic processing method. The effects of ZnO particle size on the properties of ZnO varistors are also investigated. The strong solid-state reaction during sintering may be attributed to the high surface area of the 20 nm ZnO nanoparticles that promote strong surface reaction. The intensity of XRD peaks reflected the high degree of crystallinity of the ZnO nanoparticles. However, the width of the peaks in case of ZnO nanoparticles has increased due to the quantum size effect. The cytotoxicity evaluation of ZnO varistor was conducted on mouse connective tissue fibroblast cells (L929) using Trypan Blue Exclusion Assay analysis. The results show that the four types of varistor samples lead to cellular mitochondrial dysfunction, morphological modifications and apoptosis at the various concentration range and the toxic effects are obviously displayed in high concentration samples. 20nm-VDR is the most toxic materials followed by 40nm-VDR, P8-VDR, and W4-VDR in a descending order.

Sendi, Rabab Khalid, E-mail: last-name3@hotmail.com, E-mail: shahromx@hotmail.com, E-mail: ameerah7@hotmail.com; Mahmud, Shahrom, E-mail: last-name3@hotmail.com, E-mail: shahromx@hotmail.com, E-mail: ameerah7@hotmail.com; Munshi, Ayman, E-mail: last-name3@hotmail.com, E-mail: shahromx@hotmail.com, E-mail: ameerah7@hotmail.com [Nano-optoelectronics Research and Technology Laboratory (N.O.R.), School of Physics, Universiti Sains Malaysia, 11800, Penang (Malaysia); Seeni, Azman, E-mail: azanseeni@gmail.com [Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, 13200, Bertam, Pulau Pinang (Malaysia)

2014-10-24T23:59:59.000Z

207

Fabrication of ZnO photonic crystals by nanosphere lithography using inductively coupled-plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the ZnO/GaN heterojunction light emitting diodes  

SciTech Connect (OSTI)

This article reports fabrication of n-ZnO photonic crystal/p-GaN light emitting diode (LED) by nanosphere lithography to further booster the light efficiency. In this article, the fabrication of ZnO photonic crystals is carried out by nanosphere lithography using inductively coupled plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the n-ZnO/p-GaN heterojunction LEDs. The CH{sub 4}/H{sub 2}/Ar mixed gas gives high etching rate of n-ZnO film, which yields a better surface morphology and results less plasma-induced damages of the n-ZnO film. Optimal ZnO lattice parameters of 200 nm and air fill factor from 0.35 to 0.65 were obtained from fitting the spectrum of n-ZnO/p-GaN LED using a MATLAB code. In this article, we will show our recent result that a ZnO photonic crystal cylinder has been fabricated using polystyrene nanosphere mask with lattice parameter of 200 nm and radius of hole around 70 nm. Surface morphology of ZnO photonic crystal was examined by scanning electron microscope.

Chen, Shr-Jia; Chang, Chun-Ming; Kao, Jiann-Shiun; Chen, Fu-Rong; Tsai, Chuen-Horng [Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 300 Taiwan (China); Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China)

2010-07-15T23:59:59.000Z

208

Multichannel CdZnTe Gamma Ray Spectrometer  

SciTech Connect (OSTI)

A 3 cm{sup 3} multichannel gamma spectrometer for DOE applications is under development by Digirad Corporation. The device is based on a position sensitive detector packaged in a compact multi-chip module (MCM) with integrated readout circuitry. The modular, multichannel design will enable identification and quantitative analysis of radionuclides in extended sources, or sources containing low levels of activity. The MCM approach has the advantages that the modules are designed for imaging applications, and the sensitivity can be arbitrarily increased by increasing the number of pixels, i.e. adding modules to the instrument. For a high sensitivity probe, the outputs for each pixel can be corrected for gain and offset variations, and summed digitally. Single pixel results obtained with discrete low noise readout indicate energy resolution of 3 keV can be approached with currently available CdZnTe. The energy resolution demonstrated to date with MCMs for 511 keV gamma rays is 10 keV.

F. P. Doty; C. L. Lingren; B. A. Apotovsky; J. Brunsch; J. F. Butler; T. Collins; R. L. Conwell; S. Friesenhahn; J. Gormley; B. Pi; S. Zhao (Digirad Corp., San Diego, CA); F. L. Augustine, Augustine Engineering, Encinitas, CA; B. A. Bennet; E. Cross; R. B. James (Sandia Nat'l. Labs.)

1998-07-22T23:59:59.000Z

209

Physica B 340342 (2003) 933938 EPR and electrical studies of native point defects in ZnSiP2  

E-Print Network [OSTI]

Physica B 340­342 (2003) 933­938 EPR and electrical studies of native point defects in ZnSiP2 Abstract We present the first detection of native defects in ZnSiP2. Similar to p-type ZnGeP2, the EPR lattice sites is reflected in the differences of the EPR parameters in both lattices. In both materials, V

Nabben, Reinhard

210

Hybrid structure of polyaniline/ZnO nanograss and its application in dye-sensitized solar cell with performance improvement  

SciTech Connect (OSTI)

Polyaniline (PANI) hybridized ZnO photoanode for dye-sensitized solar cell (DSSC) was primarily prepared via a two-step process which involved hydrothermal growth of ZnO nanograss on the fluorine-doped tin oxide (FTO) substrate and subsequently chemisorption of PANI on the surfaces of the ZnO nanorods. The PANI hybridized ZnO nanograss films were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), and the results indicated that there were chemical interactions between PANI and ZnO. Both pure ZnO nanograss and PANI hybridized ZnO nanograss were applied to DSSC. The results of photoelectrochemical measurement showed that the photocurrent density of PANI (100 mg/L) hybridized ZnO nanograss photoanode was significantly enhanced, and the overall light-conversion efficiency increased by 60%. The electrochemical impedance spectra (EIS) displayed that the electron densities in photoanodes of PANI hybridized ZnO nanograss were larger than that in pure ZnO nanograss. This is ascribed to more effective charge separation and faster interfacial charge transferring occurred in the hybrid photoanode. - Graphical abstract: Operational principle of the DSSC: the introduced hybridizing PANI layer performs effective charge separation and faster interfacial charge transferring. Highlights: Black-Right-Pointing-Pointer PANI/ZnO nanograss hybrid materials as photoanode in Dye-sensitized solar cell. Black-Right-Pointing-Pointer Photoelectric conversion efficiency after hybridization was enhanced by 60%. Black-Right-Pointing-Pointer PANI hybridizing ZnO nanograss induced a rapid charge separation.

Zhu Shibu; Wei Wei; Chen Xiangnan [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031 (China); Jiang Man, E-mail: jiangman1021@163.com [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031 (China); Zhou Zuowan, E-mail: zwzhou@at-c.net [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031 (China)

2012-06-15T23:59:59.000Z

211

Enhanced photovoltaic performance of nanocrystalline CdTe/ZnO solar cells using sol-gel ZnO and positive bias treatment  

SciTech Connect (OSTI)

The effect of doping and porosity of the n-type ZnO layer on the performance of solution-processed, sintered p-CdTe/n-ZnO nanocrystal photovoltaic (PV) devices is investigated. Amorphous sol-gel ZnO is found to be the best candidate with overall energy conversion efficiencies above 8% obtained if the ZnO is also indium doped. We demonstrate that when such PV devices are left under forward bias (in dark or light), the device efficiency values are raised to at least 9.8%, due to a substantially increased open-circuit voltage and fill-factor. This drastic enhancement is attributed to improved band alignment at the ITO/CdTe interface. The forward-bias treatment is slowly reversed over a period of days to weeks on standing under open circuit conditions, but is readily restored with further voltage treatment. The moderate processing conditions and high efficiency of such devices demonstrate that nanocrystal-based systems are a promising technology for photovoltaics.

MacDonald, B. I. [CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168 (Australia); School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, Victoria 3010 (Australia); Della Gaspera, E.; Watkins, S. E.; Jasieniak, J. J., E-mail: Jacek.Jasieniak@csiro.au [CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168 (Australia); Mulvaney, P. [School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, Victoria 3010 (Australia)

2014-05-14T23:59:59.000Z

212

The Effect Of ZnO Addition On Co/C Catalyst For Vapor And Aqueous Phase Reforming Of Ethanol  

SciTech Connect (OSTI)

The effect of ZnO addition on the oxidation behavior of Co along with catalytic performance in vapor and aqueous phase reforming of ethanol were investigated on Co supported on carbon black (XC-72R). Carbon was selected to minimize the support interactions. Effect of ZnO addition during both vapor and aqueous phase reforming were compared at 250 C. ZnO addition inhibited the reduction of cobalt oxides by H2 and created surface sites for H2O activation. During vapor phase reforming at 450 C the redox of cobalt, driven by steam oxidation and H2 reduction, trended to an equilibrium of Co0/Co2+. ZnO showed no significant effect on cobalt oxidation, inferred from the minor changes of C1 product yield. Surface sites created by ZnO addition enhanced water activation and oxidation of surface carbon species, increasing CO2 selectivity. At 250 C cobalt reduction was minimal, in situ XANES demonstrated that ZnO addition significantly facilitated oxidation of Co0 under vapor phase reforming conditions, demonstrated by lower C1 product yield. Sites introduced by ZnO addition improved the COx selectivity at 250 C. Both Co/C and Co-ZnO/C rapidly oxidized under aqueous phase reaction conditions at 250 C, showing negligible activity in aqueous phase reforming. This work suggests that ZnO affects the activation of H2O for Co catalysts in ethanol reforming.

Davidson, Stephen; Sun, Junming; Hong, Yongchun; Karim, Ayman M.; Datye, Abhaya K.; Wang, Yong

2014-02-05T23:59:59.000Z

213

The preparation of zinc silicate/ZnO particles and their use as an efficient UV absorber  

SciTech Connect (OSTI)

Highlights: {yields} We used innovative gel-route in order to prepare zinc silicate/ZnO nano-particles. {yields} Continuous reactor was efficient for synthesizing ZnO and zinc silicate/ZnO precursors. {yields} Introduction of Si into reaction mixture influenced on particle size and their photoactivity. {yields} Prepared particles are appropriate for UV absorbers in polymers. -- Abstract: The formation of zinc silicate/ZnO particles synthesized by a two-step method and their incorporation into PMMA is presented. In the first step a segmented-flow tubular reactor was used for the continuous room-temperature preparation of a zinc silicate/Zn(OH){sub 2} gel that was thermally treated after rinsing and drying in the second step. The same preparation procedure was also employed for the synthesis of pure ZnO and pure zinc silicate particles. It was found that the presence of the zinc silicate phase significantly influenced the final particle size, decreased the degree of crystallization and reduced the particles' UV absorption capabilities. The reduced photocatalytic activity of the zinc silicate/ZnO particles indicated that the majority of ZnO crystallites were formed inside the zinc silicate matrix. The nanocomposite prepared from zinc silicate/ZnO particles (0.04 wt.%) and PMMA showed high UV shielding and at the same time sufficient transmittance in the visible-light region.

Podbrscek, Peter [National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana (Slovenia)] [National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana (Slovenia); Drazic, Goran [Department for Nanostructured Materials, Jozef Stefan Institute, Jamova 39, SI 1000 Ljubljana (Slovenia)] [Department for Nanostructured Materials, Jozef Stefan Institute, Jamova 39, SI 1000 Ljubljana (Slovenia); Anzlovar, Alojz [National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana (Slovenia) [National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana (Slovenia); Center of Excellence for Polymer Materials and Technologies, Tehnoloski Park 24, 1000 Ljubljana (Slovenia); Orel, Zorica Crnjak, E-mail: zorica.crnjak.orel@ki.si [National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana (Slovenia); Center of Excellence for Polymer Materials and Technologies, Tehnoloski Park 24, 1000 Ljubljana (Slovenia)

2011-11-15T23:59:59.000Z

214

Phase relations and crystal structures in the system Ce-Ni-Zn at 800 Degree-Sign C  

SciTech Connect (OSTI)

Phase relations have been established for the system Ce-Ni-Zn in the isothermal section at 800 Degree-Sign C using electron microprobe analysis and X-ray powder diffraction. Phase equilibria at 800 Degree-Sign C are characterized by a large region for the liquid phase covering most of the Ce-rich part of the diagram, whereas a Zn-rich liquid is confined to a small region near the Zn-corner of the Gibbs triangle. Whereas solubility of Ce in the binary Ni-Zn phases is negligible, mutual solubilities of Ni and Zn at a constant Ce content are large at 800 Degree-Sign C for most Ce-Zn and Ce-Ni compounds. The solid solution Ce(Ni{sub 1-x}Zn{sub x}){sub 5} with the CaCu{sub 5}-type is continuous throughout the entire section and for the full temperature region from 400 to 800 Degree-Sign C. Substitution of Zn by Ni is found to stabilize the structure of CeZn{sub 11} to higher temperatures. At 800 Degree-Sign C Ce(Ni{sub x}Zn{sub 1-x}){sub 11} (0.03{<=}x{<=}0.22) appears as a ternary solution phase. Similarly, a rather extended solution forms for Ce{sub 2}(Ni{sub x}Zn{sub 1-x}){sub 17} (0{<=}x{<=}0.53). Detailed data on atom site occupation and atom parameters were derived from X-ray structure analyses for single crystals of Ce{sub 2+y}(Ni{sub x}Zn{sub 1-x}){sub 17}, y=0.02, x=0.49 (a=0.87541(3), c=1.25410(4) nm; Th{sub 2}Zn{sub 17} type with space group R3{sup Macron }m,R{sub F{sup 2}}=0.018) and Ce(Ni{sub 0.18}Zn{sub 0.82}){sub 11} (a=1.04302(2), c=0.67624(3)nm, BaCd{sub 11} type with space group I4{sub 1}/amd, R{sub F{sup 2}}=0.049). - Graphical abstract: Ce-Ni-Zn isothermal section at 800 Degree-Sign C. Highlights: Black-Right-Pointing-Pointer Phase relations were determined for the system Ce-Ni-Zn in the section at 800 Degree-Sign C. Black-Right-Pointing-Pointer A continuous solid solution Ce(Ni{sub 1-x}Zn{sub x}){sub 5}, 0{<=}x{<=}1, forms between 400 and 800 Degree-Sign C. Black-Right-Pointing-Pointer Zn/Ni substitution stabilizes the ternary phase Ce(Zn{sub 1-x}Ni{sub x}){sub 11}, 0.03{<=}x{<=}0.22, 800 Degree-Sign C. Black-Right-Pointing-Pointer An extended solution forms for Ce{sub 2}(Ni{sub x}Zn{sub 1-x}){sub 17} (0{<=}x{<=}0.53). Black-Right-Pointing-Pointer Crystal data are given: Ce{sub 2+y}(Ni{sub x}Zn{sub 1-x}){sub 17} (Th{sub 2}Zn{sub 17}), Ce(Ni{sub 0.18}Zn{sub 0.82}){sub 11} (BaCd{sub 11}).

Malik, Z.; Grytsiv, A. [Institute of Physical Chemistry, University of Vienna, Waehringerstrasse 42, A-1090 Vienna (Austria)] [Institute of Physical Chemistry, University of Vienna, Waehringerstrasse 42, A-1090 Vienna (Austria); Rogl, P., E-mail: peter.franz.rogl@univie.ac.at [Institute of Physical Chemistry, University of Vienna, Waehringerstrasse 42, A-1090 Vienna (Austria); Giester, G. [Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria)] [Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria)

2012-10-15T23:59:59.000Z

215

Copper doping of ZnO crystals by transmutation of {sup 64}Zn to {sup 65}Cu: An electron paramagnetic resonance and gamma spectroscopy study  

SciTech Connect (OSTI)

Transmutation of {sup 64}Zn to {sup 65}Cu has been observed in a ZnO crystal irradiated with neutrons. The crystal was characterized with electron paramagnetic resonance (EPR) before and after the irradiation and with gamma spectroscopy after the irradiation. Major features in the gamma spectrum of the neutron-irradiated crystal included the primary 1115.5?keV gamma ray from the {sup 65}Zn decay and the positron annihilation peak at 511?keV. Their presence confirmed the successful transmutation of {sup 64}Zn nuclei to {sup 65}Cu. Additional direct evidence for transmutation was obtained from the EPR of Cu{sup 2+} ions (where {sup 63}Cu and {sup 65}Cu hyperfine lines are easily resolved). A spectrum from isolated Cu{sup 2+} (3d{sup 9}) ions acquired after the neutron irradiation showed only hyperfine lines from {sup 65}Cu nuclei. The absence of {sup 63}Cu lines in this Cu{sup 2+} spectrum left no doubt that the observed {sup 65}Cu signals were due to transmuted {sup 65}Cu nuclei created as a result of the neutron irradiation. Small concentrations of copper, in the form of Cu{sup +}-H complexes, were inadvertently present in our as-grown ZnO crystal. These Cu{sup +}-H complexes are not affected by the neutron irradiation, but they dissociate when a crystal is heated to 900?C. This behavior allowed EPR to distinguish between the copper initially in the crystal and the copper subsequently produced by the neutron irradiation. In addition to transmutation, a second major effect of the neutron irradiation was the formation of zinc and oxygen vacancies by displacement. These vacancies were observed with EPR.

Recker, M. C.; McClory, J. W., E-mail: John.McClory@afit.edu; Holston, M. S.; Golden, E. M.; Giles, N. C. [Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio 45433 (United States); Halliburton, L. E. [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States)

2014-06-28T23:59:59.000Z

216

akkumulyatorov ot solnechnoj: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

L2.9+-0.5x105 Lsun. Assuming spherical geometry, the black body effective radius, R2.0+-0.5x104 Rsun, and corresponding expansion velocity, v870+-260 kms, are remarkably...

217

James L. Liveman, Acting AssLBtaOt  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$ EGcG ENERGYELIkNATIONHEALXH: l ._I *r'.Jq. 1 '1 - *

218

Relaxation in ZnO (1010), (0001), and (0001) surfaces and the adsorption of CO  

SciTech Connect (OSTI)

An atom superposition and electron delocalization molecular orbital study using cluster models shows surface zinc and oxygen ions relax into the (0001), (0001), and (1010) surfaces. The unsaturated zinc ions present surface states consisting of empty 4s, 4p hybridized orbitals with energy levels beneath the empty 4s, 4p band. The filled bands are O 2p nonbonding, Zn 4s + O 2p bonding, and Zn 3d, in order of increasing ionization potential. A study of CO adsorption to an unsaturated zinc ion on the (1010) surface produces an adsorption energy of 12 kcal/mol, a CO bond length decrease of 0.02 A, and an increase in the CO stretching force constant. The zinc ion unrelaxes to a position above the bulk-like position when CO is coordinated to it. The bonding of CO to zinc consists in closed shell sigma donation interactions of the CO 5sigma orbital with the filled Zn 3d and Zn 4s + O 2p bands with the antibonding counterpart stabilized by the Zn 4s, 4p surface state orbital. This 5sigma donation strengthens the CO bond and transfers charge to the surface. These results support a number of experimental structural, vibrational, and electronic studies in the literature.

Anderson, A.B.; Nichols, J.A.

1986-04-02T23:59:59.000Z

219

X-ray Characterisation of Zinc Oxide (ZnO) Single Crystal Substrates  

SciTech Connect (OSTI)

Single crystal substrates of low defect density are paramount for fully realizing the numerous applications of zinc oxide (ZnO) wide bandgap semiconductors. While ZnO substrates are commercially available from various vendors, very little information is available on the structural properties of these substrates. Therefore, an extensive evaluation of available substrates would serve as a basis for the development of ZnO based devices and technologies. In this study, bulk ZnO single crystal substrates grown by different growth techniques have been characterised using synchrotron white beam X-ray topography and high resolution X-ray diffraction. The substrates exhibit a wide range of dislocation densities from as high as 10{sup 6} cm{sup -2} down to less than 1000 cm{sup -2} depending on the growth technique employed. The authors evaluation reveals that ZnO crystals grown by the hydrothermal technique possess the best structural quality with dislocation densities of 800-1000 cm{sup -2} and rocking curves with a full width half maximum of less than 12 arc seconds.

Dhanaraj, G.; Raghothamachar, B; Dudley, M

2010-01-01T23:59:59.000Z

220

Electroluminescence from ZnO/Si heterojunctions fabricated by PLD with bias voltage application  

SciTech Connect (OSTI)

Electroluminescence (EL) for ZnO films has been investigated by fabricating n-ZnO/p-Si heterojunctions and changing the VI/II (O/Zn) ratio of the films. In the photoluminescence (PL) spectra, both the near band edge (NBE) emission and the defect-related emission were observed, while in the EL spectra only defect-related emission was observed. The EL spectra were divided into three components: green (550 nm), yellow (618 nm) and red (700 nm) bands; and their intensities were compared. As the VI/II (O/Zn) ratio was increased, the red band emission intensity decreased and the green band emission intensity increased. This implies that the oxygen and the zinc vacancies are related to the red and the green band emissions, respectively. Electron transitions from the conduction band minimum (Ec) to the deep energy levels of these vacancies are suggested to cause the red and the green luminescences while the energy levels of the Zn interstitials are close to the Ec in the band gap and no NBE emission is observed.

Seno, Yuuki; Konno, Daisuke; Komiyama, Takao; Chonan, Yasunori; Yamaguchi, Hiroyuki; Aoyama, Takashi [Electronics and Information Systems, Akita Prefectural Univ. Yuri-honjo, Akita 015-0055 (Japan)

2014-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Emission dynamics of an expanding ultrafast-laser produced Zn plasma under different ambient pressures  

SciTech Connect (OSTI)

We report time and space resolved spectral measurements of neutral Zn emission from an ultrafast laser produced plasma, generated by the irradiation of a Zn target with laser pulses of 100 femtoseconds duration, carried out in a broad ambient pressure range of 0.05 to 100 Torr. The measurement is done for three different axial positions in the expanding plume. The spectra are rich in neutral Zn (Zn I) emissions at 334.5 nm, 468 nm, 472 nm, 481 nm, and 636 nm, respectively, depicting the characteristic triplet structure of Zn. Fast as well as slow peaks are observed in the time of flight data of 481 nm emission, which arise from recombination and atomic contributions, respectively, occurring at different time scales. Average speeds of the fast atomic species do not change appreciably with ambient pressure. The plasma parameters (electron temperature and number density) are evaluated from the measured optical emission spectra. The rates of ionization and recombination can be enhanced by a double-pulse excitation configuration in which optical energy is coupled to the ultrafast plasma through a delayed laser pulse.

Smijesh, N.; Philip, Reji [Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)] [Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)

2013-09-07T23:59:59.000Z

222

Top-illuminated dye-sensitized solar cells with a room-temperature-processed ZnO photoanode on metal substrates and a Pt-coated Ga-doped ZnO counter electrode  

E-Print Network [OSTI]

Top-illuminated dye-sensitized solar cells with a room-temperature-processed ZnO photoanode.1088/0022-3727/44/4/045102 Top-illuminated dye-sensitized solar cells with a room-temperature-processed ZnO photoanode on metal in this article are in colour only in the electronic version) 1. Introduction Dye-sensitized solar cells (DSCs

Demir, Hilmi Volkan

223

FINAL REPORT OF RESEARCH ON CuxS/ (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79  

E-Print Network [OSTI]

and (Cd,Zn)S/CuxS photovoltaic cells. The approach was tothe CuxS/(Cd,Zn)S photovoltaic cell in order to betterstudying CdS/CuxS photovoltaic cells, films prepared by the

Chin, B.L.

2013-01-01T23:59:59.000Z

224

On the variations of optical property and electronic structure in heavily Al-doped ZnO films during double-step growth process  

SciTech Connect (OSTI)

We have investigated the variations of optical property and electronic structure in heavily Al-doped ZnO (AZO) films during the growth process, which were formed by first creating Zn vacancies in O{sub 2}-rich atmosphere and second filling the vacancies with Zn atoms in Zn-vapor atmosphere. After the first step, the high-resistance AZO films have the same optical bandgap with nominally undoped ZnO, indicating that negligible variations in the fundamental bandgap happened to the AZO films although Al atom was incorporated into the ZnO lattice. After the second step, once free electrons were brought into the lattice by Zn-filling, the optical transition energy blueshifts due to the band-filling effect. X-ray absorption fine structure measurements suggest that Zn-filling process decreased the unoccupied states of the conduction band, but not raised the conduction band minimum.

Hu, Q. C.; Ding, K., E-mail: kding@fjirsm.ac.cn; Zhang, J. Y.; Yan, F. P.; Pan, D. M.; Huang, F., E-mail: fhuang@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chiou, J. W., E-mail: jwchiou@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

2014-01-13T23:59:59.000Z

225

Growth and optical properties of CdTe quantum dots in ZnTe nanowires  

SciTech Connect (OSTI)

We report on the formation of optically active CdTe quantum dots in ZnTe nanowires. The CdTe/ZnTe nanostructures have been grown by a gold nanocatalyst assisted molecular beam epitaxy in a vapor-liquid solid growth process. The presence of CdTe insertions in ZnTe nanowire results in the appearance of a strong photoluminescence band in the 2.0 eV-2.25 eV energy range. Spatially resolved photoluminescence measurements reveal that this broad emission consists of several sharp lines with the spectral width of about 2 meV. The large degree of linear polarization of these individual emission lines confirms their nanowire origin, whereas the zero-dimensional confinement is proved by photon correlation spectroscopy.

Wojnar, Piotr; Janik, Elzbieta; Baczewski, Lech T.; Kret, Slawomir; Karczewski, G.; Wojtowicz, Tomasz [Institute of Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warsaw (Poland); Goryca, Mateusz; Kazimierczuk, Tomasz; Kossacki, Piotr [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul Hoza 69, 00-681 Warsaw (Poland)

2011-09-12T23:59:59.000Z

226

Band offsets in HfO{sub 2}/InGaZnO{sub 4} heterojunctions  

SciTech Connect (OSTI)

The valence band discontinuity ({Delta}E{sub V}) of sputter deposited HfO{sub 2}/InZnGaO{sub 4} (IGZO) heterostructures was obtained from x-ray photoelectron spectroscopy measurements. The HfO{sub 2} exhibited a bandgap of 6.07 eV from absorption measurements. A value of {Delta}E{sub V} = 0.48 {+-} 0.025 eV was obtained by using the Ga 2p{sub 3/2}, Zn 2p{sub 3/2}, and In 3d{sub 5/2} energy levels as references. This implies a conduction band offset {Delta}E{sub C} of 2.39 eV in HfO{sub 2}/InGaZnO{sub 4} heterostructures and a nested interface band alignment.

Cho, Hyun [Department of Nanomechatronics Engineering, Pusan National University, Gyeongnam 627-706 (Korea, Republic of); Douglas, E. A.; Gila, B. P.; Craciun, V.; Lambers, E. S.; Pearton, S. J. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ren Fan [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2012-01-02T23:59:59.000Z

227

Reliable self-powered highly spectrum-selective ZnO ultraviolet photodetectors  

SciTech Connect (OSTI)

Ultraviolet photodetectors (PDs) have been fabricated from p-ZnO:(Li,N)/n-ZnO structures in this Letter. The PDs can operate without any external power supply and show response only to a very narrow spectrum range. The self-power character of the devices is due to the built-in electric field in the p-n junctions that can separate the photogenerated electrons and holes while the high spectrum-selectivity has been attributed to the filter effect of the neutral region in the ZnO:(Li,N) layer. The performance of the self-powered highly spectrum-selective PDs degrades little after five months, indicating their good reliability.

Shen, H. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China) [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shan, C. X., E-mail: shancx@ciomp.ac.cn, E-mail: binghuili@163.com; Li, B. H., E-mail: shancx@ciomp.ac.cn, E-mail: binghuili@163.com; Shen, D. Z. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Xuan, B. [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2013-12-02T23:59:59.000Z

228

Homojunction p-n photodiodes based on As-doped single ZnO nanowire  

SciTech Connect (OSTI)

Photovoltaic device was successfully grown solely based on the single ZnO p-n homojunction nanowire. The ZnO nanowire p-n diode consists of an as-grown n-type segment and an in-situ arsenic doped p-type segment. This p-n homojunction acts as a good photovoltaic cell, producing a photocurrent almost 45 times larger than the dark current under reverse-biased condition. Our results demonstrate that present ZnO p-n homojunction nanowire can be used as a self-powered ultraviolet photodetector as well as a photovoltaic cell, which can also be used as an ultralow electrical power source for nano-scale electronic, optoelectronic, and medical devices.

Cho, H. D.; Zakirov, A. S.; Yuldashev, Sh. U.; Kang, T. W. [Quantum-Functional Semiconductor Research Center, Dongguk Univ.-Seoul, Seoul 100-715 (Korea, Republic of); Ahn, C. W. [Nano-materials Lab. National Nanofab Center at KAIST, 335 Gwahangno, Daejeon 305-806 (Korea, Republic of); Yeo, Y. K. [Department of Engineering Physics, Air Force Institute of Technology,Wright-Patterson AFB, OH 45433 (United States)

2013-12-04T23:59:59.000Z

229

Tunable mechanical and thermal properties of ZnS/CdS core/shell nanowires  

E-Print Network [OSTI]

Using all atom molecular dynamics (MD) simulations, we have studied the mechanical properties of ZnS/CdS core/shell nanowires. Our results show that the coating of a few atomic layer CdS shell on the ZnS nanowire leads to a significant change in the stiffness of the core/shell nanowires compared to the stiffness of pure ZnS nanowires. The binding energy between the core and shell region decreases due to the lattice mismatch at the core-shell interface. This reduction in binding energy plays an important role in determining the stiffness of a core/shell nanowire. We have also investigated the effects of the shell on the thermal conductivity and melting behavior of the nanowires.

Mandal, Taraknath; Maiti, Prabal K

2015-01-01T23:59:59.000Z

230

Measuring size dependent electrical properties from nanoneedle structures: Pt/ZnO Schottky diodes  

SciTech Connect (OSTI)

This work reports the fabrication and testing of nanoneedle devices with well-defined interfaces that are amenable to a variety of structural and electrical characterization, including transmission electron microscopy. Single Pt/ZnO nanoneedle Schottky diodes were fabricated by a top down method using a combination of electro-polishing, sputtering, and focused ion beam milling. The resulting structures contained nanoscale planar heterojunctions with low ideality factors, the dimensions of which were tuned to study size-dependent electrical properties. The diameter dependence of the Pt/ZnO diode barrier height is explained by a joule heating effect and/or electronic inhomogeneity in the Pt/ZnO contact area.

Mao, Shimin; Anderson, Daniel D. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Shang, Tao [Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Park, Byoungnam [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Materials Science and Engineering, Hongik University, 72-1 Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of); Dillon, Shen J., E-mail: sdillon@illinois.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

2014-04-14T23:59:59.000Z

231

Substrate Atomic-Termination-Induced Anisotropic Growth of ZnO Nanowires/Nanorods by the VLS Process  

E-Print Network [OSTI]

Substrate Atomic-Termination-Induced Anisotropic Growth of ZnO Nanowires/Nanorods by the VLSO substrate, we demonstrate the effect of substrate surface termination on nanowire growth. Symmetric) substrates have asymmetrically grown nanostructures. For the Zn-terminated (0001) substrate surface, uniform

Wang, Zhong L.

232

Dissolved trace metals (Ni, Zn, Co, Cd, Pb, Al, and Mn) around the Crozet Islands, Southern Ocean  

E-Print Network [OSTI]

of trace elements such as Zn, Co, and Cd may be influenced by complexing ligands [e.g., Zn: Bruland, 1989; Ellwood and van den Berg, 2000; Co: Ellwood and van den Berg, 2001; Saito et al., 2004; Cd: Bruland, 1992

Paris-Sud XI, Universit de

233

Temperature dependence of magnetic behaviour in very fine grained, spark plasma sintered NiCuZn Ferrites  

E-Print Network [OSTI]

CuZn Ferrites Behzad Ahmadi,1, a) Karim Zehani,1 Martino LoBue,1 Vincent Loyau,1 and Frederic Mazaleyrat1 SATIE spark plasma sintering technique, a family of very fine grained, fully dense NiCuZn ferrites have been produced which show constant permeability up to several 10 MHz. These Ferrites can be used for filtering

Boyer, Edmond

234

Growth of Single-and Bilayer ZnO on Au(111) and Interaction with Xingyi Deng,*,,,  

E-Print Network [OSTI]

Growth of Single- and Bilayer ZnO on Au(111) and Interaction with Copper Xingyi Deng,*,,, Kun Yao of Sciences, Dalian 116023, China URS, P.O. Box 618, South Park, Pennsylvania 15129, United States *S for the structure of the grown ultrathin ZnO, in particular how important the interaction between the substrate

Li, Weixue

235

DOI: 10.1002/adma.200602927 Hierarchically Structured ZnO Film for Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

DOI: 10.1002/adma.200602927 Hierarchically Structured ZnO Film for Dye-Sensitized Solar Cells* The interest in dye-sensitized solar cells has increased due to reduced energy sources and higher energy, zinc oxide (ZnO) has recently been explored as an alternative material in dye-sensitized solar cells

Cao, Guozhong

236

Flexible dye-sensitized solar cells with ZnO nanoparticles grown by Sonochemistry over Graphene/PET substrates.  

E-Print Network [OSTI]

Flexible dye-sensitized solar cells with ZnO nanoparticles grown by Sonochemistry over Graphene and Engineering University of North Texas, Denton, Texas Flexible Dye sensitized solar cells (FDSSCs) are light characteristics of ZnO nanostructures over Graphene/PET as photoanode for flexible dye sensitized solar cells. #12;

Pala, Nezih

237

Absorption spectra of CdSe-ZnS core-shell quantum dots at high photon energies : experiment and modeling  

E-Print Network [OSTI]

Absorption spectra of CdSe-ZnS core-shell quantum dots at high photon energies : experiment spectra of CdSe-ZnS core-shell quantum dot (QD) ensembles, with average core diameters ranging from 2.6 nm. In agreement with previous reports, the absorption coefficient at energies 1 eV above the effective bandgap

Ghosh, Sandip

238

Reversible Modification of CdSe-CdS/ZnS Quantum Dot Fluorescence by Surrounding Ca2+  

E-Print Network [OSTI]

Reversible Modification of CdSe-CdS/ZnS Quantum Dot Fluorescence by Surrounding Ca2+ Ions Li Li (3-MPA) coated CdSe-CdS/ZnS core-multishell QDs when free Ca2+ ions were added to and subsequently removed from the QD solution. It was found that QD fluorescence intensity was reduced when Ca2+ ions were

Haviland, David

239

Synthesis and Characterization of Ag-or Sb-Doped ZnO Nanorods by a Facile Hydrothermal Route  

E-Print Network [OSTI]

Synthesis and Characterization of Ag- or Sb-Doped ZnO Nanorods by a Facile Hydrothermal Route Oleg Stefan Cel Mare BouleVard, MD-2004 Chisinau, Republic of MoldoVa, AdVanced Materials Processing ZnO nanorods doped with Ag and Sb have been synthesized by a facile hydrothermal technique. Crystal

Kik, Pieter

240

Formation of Crystalline Zn-Al Layered Double Hydroxide Precipitates on Alumina: The Role of Mineral Dissolution  

E-Print Network [OSTI]

Formation of Crystalline Zn-Al Layered Double Hydroxide Precipitates on Alumina: The Role) phases in soils, we systematically examined the presence of Al and the role of mineral dissolution during Zn sorption/precipitation on -Al2O3 (-alumina) at pH 7.5 using extended X-ray absorption fine

Sparks, Donald L.

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Far-infrared optical and dielectric response of ZnS measured by terahertz time-domain spectroscopy  

E-Print Network [OSTI]

Far-infrared optical and dielectric response of ZnS measured by terahertz time-domain spectroscopy material in the infrared and far-infrared region.1 It plays a vital role in being used as infrared windows the frequency-dependent optical properties and complex di- electric response of ZnS over a broad far-infrared

242

Simplifying strong electronic correlations in uranium: Localized uranium heavy-fermion UM2Zn20 (M=Co,Rh) compounds  

E-Print Network [OSTI]

Simplifying strong electronic correlations in uranium: Localized uranium heavy-fermion UM2Zn20 (M Atómica, 8400 Bariloche, Argentina 6 Department of Chemistry and Biochemistry, University of Delaware-field effects corroborate an ionic-like uranium electronic configura- tion in UM2Zn20. DOI: 10.1103/PhysRevB.78

Lawrence, Jon

243

Determination of secondary ion mass spectrometry relative sensitivity factors for polar and non-polar ZnO  

SciTech Connect (OSTI)

Zinc oxide (ZnO) is regarded as a promising material for optoelectronic devices, due to its electronic properties. Solely, the difficulty in obtaining p-type ZnO impedes further progress. In this connection, the identification and quantification of impurities is a major demand. For quantitative information using secondary ion mass spectrometry (SIMS), so-called relative sensitivity factors (RSF) are mandatory. Such conversion factors did not yet exist for ZnO. In this work, we present the determined RSF values for ZnO using primary (ion implanted) as well as secondary (bulk doped) standards. These RSFs have been applied to commercially available ZnO substrates of different surface termination (a-plane, Zn-face, and O-face) to quantify the contained impurities. Although these ZnO substrates originate from the same single-crystal, we observe discrepancies in the impurity concentrations. These results cannot be attributed to surface termination dependent RSF values for ZnO.

Laufer, Andreas; Volbers, Niklas; Eisermann, Sebastian; Meyer, Bruno K. [Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany); Potzger, Kay [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany); Geburt, Sebastian; Ronning, Carsten [Institut fuer Festkoerperphysik, Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

2011-11-01T23:59:59.000Z

244

Interaction of light with the ZnO surface: Photon induced oxygen "breathing," oxygen vacancies, persistent photoconductivity,  

E-Print Network [OSTI]

Interaction of light with the ZnO surface: Photon induced oxygen "breathing," oxygen vacancies donation of oxygen vacancies. Our findings suggest that the observed decomposition of the ZnO lattice may. The formation of oxygen-vacancy rich surface is suggested to induce surface delta doping, causing accumulation

Shalish, Ilan

245

Growth Mechanism and Electronic Structure of Zn3P2 on the Ga-Rich GaAs(001) Surface  

E-Print Network [OSTI]

as well as the potential for low-cost, thin-film fabrication make Zn3P2 a promising active material Zn3P2 films on III-V substrates unlocks a promising pathway toward high-efficiency, earth-abundant photovoltaic devices fabricated on reusable, single-crystal templates. The detailed chemical, structural

Atwater, Harry

247

Study of Even-Even/Odd-Even/Odd-Odd Nuclei in Zn-Ga-Ge Region in the Proton-Neutron IBM/IBFM/IBFFM  

SciTech Connect (OSTI)

We study the even-even, odd-even and odd-odd nuclei in the region including Zn-Ga-Ge in the proton-neutron IBM and the models derived from it: IBM2, IBFM2, IBFFM2. We describe {sup 67}Ga, {sup 65}Zn, and {sup 68}Ga by coupling odd particles to a boson core {sup 66}Zn. We also calculate the beta{sup +}-decay rates among {sup 68}Ge, {sup 68}Ga and {sup 68}Zn.

Yoshida, N. [Faculty of Informatics, Kansai University, Takatsuki 569-1095 (Japan); Brant, S. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Zuffi, L. [Dipartimento di Fisica dell'Universita di Milano and Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, Milano 20133 (Italy)

2009-08-26T23:59:59.000Z

248

Preparation and characterization of nanodiamond cores coated with a thin Ni-Zn-P alloy film  

SciTech Connect (OSTI)

Nanodiamond cores coated with a thin Ni-Zn-P alloy film were prepared by an electroless deposition method under the conditions of tin chloride sensitization and palladium chloride activation. The prepared materials were analyzed by Fourier transform infrared (FTIR) spectrometry and X-ray diffraction (XRD). The nanostructure of the materials was then characterized by transmission electron microscopy (TEM). The alloy film composition was characterized by Energy Dispersive X-ray (EDX) analysis. The results indicated the approximate composition 49.84%Ni-37.29%Zn-12.88%P was obtained.

Wang Rui; Ye Weichun; Ma Chuanli [College of Chemistry and Chemical Engineering, Lanzhou University, 730000 Lanzhou (China); Wang Chunming [College of Chemistry and Chemical Engineering, Lanzhou University, 730000 Lanzhou (China)], E-mail: wangcm@lzu.edu.cn

2008-02-15T23:59:59.000Z

249

Time resolved optical diagnostics of ZnO plasma plumes in air  

SciTech Connect (OSTI)

We report dynamical evolution of laser ablated ZnO plasma plumes using interferometry and shadowgraphy; 2-D fast imaging and optical emission spectroscopy in air ambient at atmospheric pressure. Recorded interferograms using Nomarski interferometer and shadowgram images at various time delays show the presence of electrons and neutrals in the ablated plumes. The inference drawn from sign change of fringe shifts is consistent with two dimensional images of the plume and optical emission spectra at varying time delays with respect to ablating pulse. Zinc oxide plasma plumes are created by focusing 1.06 ?m radiation on to ZnO target in air and 532 nm is used as probe beam.

Gupta, Shyam L.; Singh, Ravi Pratap; Thareja, Raj K. [Department of Physics, Indian Institute of Technology Kanpur, Kanpur - 208016 (U. P.) (India)] [Department of Physics, Indian Institute of Technology Kanpur, Kanpur - 208016 (U. P.) (India)

2013-10-15T23:59:59.000Z

250

Double beta decay of ^{64,70}Zn and ^{180,186}W isotopes  

E-Print Network [OSTI]

The results of the experimental investigations of double beta processes in Zinc and Tungsten isotopes with the help of middle volume (117 g, 168 g and 699 g) low-background ZnWO_4 crystal scintillators are presented. The experiment was carried out in the low-background "DAMA/R&D" set-up at the Gran Sasso National Laboratories of the INFN (Italy) at a depth of \\approx3600 m w.e. The total measurement time exceeds ten thousand hours. New improved half-life limits on double electron capture and electron capture with positron emission in ^{64}Zn have been set: T^{2\

D. V. Poda

2011-12-05T23:59:59.000Z

251

Laser Treatment of Ag@ZnO Nanorods as Long Life Span SERS Surfaces  

E-Print Network [OSTI]

on semiconductor nanorods or nanowires of Si, Ge or ZnO, have led to significant enhancements in Raman scattering. 18,19 These evidences have prompted the study of composites or heterostructures formed by semiconductors and noble metals to promote higher SERS... of Surface-Enhanced Raman Scattering in ZnO Nanocrystals. J. Raman Spectrosc., 2009, 40, 1072-1077. 18 Li, X. H.; Chen, G. Y.; Yang, L. B.; Jin Z.; Liu, J. H. Multifunctional Au-Coated TiO2 Nanotube Arrays as Recyclable SERS Substrates for Multifold...

Macias-Montero, Manuel; J. Pelez, Ramn; Rico, Victor J.; Saghi, Zineb; Midgley, Paul; Afonso, Carmen N.; Gonzlez-Elipe, Agustn R.; Borras, Ana

2015-01-09T23:59:59.000Z

252

Laser Treatment of Ag@ZnO Nanorods as Long-Life-Span SERS Surfaces  

E-Print Network [OSTI]

on semiconductor nanorods or nanowires of Si, Ge or ZnO, have led to significant enhancements in Raman scattering. 18,19 These evidences have prompted the study of composites or heterostructures formed by semiconductors and noble metals to promote higher SERS... of Surface-Enhanced Raman Scattering in ZnO Nanocrystals. J. Raman Spectrosc., 2009, 40, 1072-1077. 18 Li, X. H.; Chen, G. Y.; Yang, L. B.; Jin Z.; Liu, J. H. Multifunctional Au-Coated TiO2 Nanotube Arrays as Recyclable SERS Substrates for Multifold...

Macias-Montero, Manuel; Pelez, Ramn J.; Rico, Victor J.; Saghi, Zineb; Midgley, Paul; Afonso, Carmen N.; Gonzlez-Elipe, Agustn R.; Borras, Ana

2015-01-09T23:59:59.000Z

253

Impurity Diffusion Coefficients of Al and Zn in Mg Determined from Solid-to-Solid Diffusion Couples  

SciTech Connect (OSTI)

Increasing use and development of lightweight Mgalloys have led to the desire for more fundamental research in and understanding of Mg-based systems. As property enhancing components, Al and Zn are two of the most important and common alloying elements for Mg-alloys. We have investigated the concentration dependent interdiffusion of Al and Zn in Mg using diffusion couples of pure polycrystalline Mg mated to Mg solid solutions containing either <9 at.% Al or <3 at.% Zn. Concentration profiles were determined by electron micro-probe microanalysis of the diffusion zone. The interdiffusion coefficients were determined by the classical Boltzmann-Matano method within the Mg solid solution. As the concentration of Al or Zn approaches the dilute ends, we employ an analytical approach based on the Hall method to estimate the impurity diffusion coefficients. Results of Al and Zn impurity diffusion in Mg are reported and compared to published impurity diffusion coefficients typically determined by thin film techniques.

Kammerer, Catherine [University of Central Florida, Orlando; Kulkarni, Nagraj S [ORNL; Warmack, Robert J Bruce [ORNL; Perry, Kelly A [ORNL; Belova, Irina [University of Newcastle, NSW, Australia; Murch, Prof. Graeme [University of Newcastle, NSW, Australia; Sohn, Yong Ho [University of Central Florida

2013-08-01T23:59:59.000Z

254

Engineering of optical polarization based on electronic band structures of A-plane ZnO layers under biaxial strains  

SciTech Connect (OSTI)

In-plane anisotropic strains in A-plane layers on the electronic band structure of ZnO were investigated from the viewpoint of optical polarization anisotropy. Investigations utilizing kp perturbation theory revealed that energy transitions and associated oscillation strengths were dependent on in-plane strains. The theoretical correlation between optical polarizations and in-plane strains was experimentally demonstrated using A-plane ZnO layers with different in-plane strains. Finally, optical polarization anisotropy and its implications for in-plane optical properties are discussed in relation to the energy shift between two orthogonal directions. Higher polarization rotations were obtained in an A-plane ZnO layer with in-plane biaxially compressive strains as compared to strain-free ZnO. This study provides detailed information concerning the role played by in-plane strains in optically polarized applications based on nonpolar ZnO in the ultra-violet region.

Matsui, Hiroaki, E-mail: hiroaki@ee.t.u-tokyo.ac.jp; Tabata, Hitoshi [Department of Bioengineering, The University of Tokyo, 1-3-7 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Electrical Engineering and Information Systems, The University of Tokyo, 1-3-7 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Hasuike, Noriyuki; Harima, Hiroshi [Department of Electronics and Information Science, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan)

2014-09-21T23:59:59.000Z

255

Effects of Dye Loading Conditions on the Energy Conversion Efficiency of ZnO and TiO2 Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

light conversion efficiency of zinc oxide (ZnO) film electrodes in dye-sensitized solar cellsO) has been explored as an alternative material in dye-sensitized solar cells. The use of Zn as an alternative material for improving the solar cell performance in dye-sensitized solar cells due to (1) Zn

Cao, Guozhong

256

Role of copper in the regulation of CU, ZN-superoxide dismutase in human K562 erythroleukemia cells and human fibroblasts  

E-Print Network [OSTI]

Activation of the enzyme CU2Zn2-SUperoxide dismutase (CuZnSOD) by its copper cofactor was studied in K562 erythroleukemia cells and skin fibroblasts. K562 cells were incubated in medium supplemented with 0-50 IIM CUC12 or ZnCI2 for 24 h and extracts...

Yu, Dan

1994-01-01T23:59:59.000Z

257

An organic hydrogel film with micron-sized pillar array for real-time and indicator-free detection of Zn2+  

E-Print Network [OSTI]

-time and indicator-free detection of Zn2+ is developed by embedding a fluorescent indicator 11,16-bis(phenyl)-6 in the hippocampus, amygdale, cortex gray, and olfactory bulb regions [2]. Most of Zn2+ are bound to proteins;Fluorescent microscopy is conventionally used to detect Zn2+ with the help of fluorescent indicators since

Meng, Hsin-Fei

258

Structure and stability of NH complexes in single-crystal ZnO S. J. Jokela and M. D. McCluskeya  

E-Print Network [OSTI]

Received 20 March 2010; accepted 4 May 2010; published online 11 June 2010 Zinc oxide ZnO is semiconductor.1063/1.3443457 I. INTRODUCTION The renewed interest in zinc oxide ZnO has continued to grow over the last decade conductor.2 ZnO is already prevalent in industry, in devices such as solar cells3 and varistors.4 Research

McCluskey, Matthew

259

Core-shell multi-quantum wells in ZnO / ZnMgO nanowires with high optical efficiency at room temperature  

E-Print Network [OSTI]

Nanowire-based light-emitting devices require multi-quantum well heterostructures with high room temperature optical efficiencies. We demonstrate that such efficiencies can be attained through the use of ZnO/Zn(1-x)MgxO core shell quantum well heterostructures grown by metal organic vapour phase epitaxy. Varying the barrier Mg concentration from x=0.15 to x=0.3 leads to the formation of misfit induced dislocations in the multi quantum wells. Correlatively, temperature dependant photoluminescence reveals that the radial well luminescence intensity decreases much less rapidly with increasing temperature for the lower Mg concentration. Indeed, about 54% of the 10K intensity is retained at room temperature with x=0.15, against 2% with x=0.30. Those results open the way to the realization of high optical efficiency nanowire-based light emitting diodes.

Thierry, Robin; Jouneau, Pierre-Henri; Ferret, Pierre; Feuillet, Guy; 10.1088/0957-4484/23/8/085705

2013-01-01T23:59:59.000Z

260

Energy level alignment of polythiophene/ZnO hybrid solar cells  

E-Print Network [OSTI]

Energy level alignment of polythiophene/ZnO hybrid solar cells W. Feng,a S. Rangan,b Y. Cao,c E between energy level alignment and photovoltaic properties of a model bilayer hybrid solar cell. Galoppini,c R. A. Bartynskib and E. Garfunkel*ab Energy level alignment at interfaces is critical

Garfunkel, Eric

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Scalable production of microbially-mediated ZnS nanoparticles and application to functional thin films  

SciTech Connect (OSTI)

A series of semiconducting zinc sulfide (ZnS) nanoparticles were scalably, reproducibly, controllably, and economically synthesized with anaerobic metal-reducing Thermoanaerobacter species. They reduced partially oxidized sulfur sources to sulfides that extracellularly and thermodynamically incorporated with zinc ions to produce sparingly soluble ZnS nanoparticles with ~5 nm crystallites at yields of ~5 g l 1 month 1. A predominant sphalerite formation was facilitated by rapid precipitation kinetics, low cation/anion ratio, higher zinc concentration, water stabilization, or some combination of the four. The sphalerite ZnS nanoparticles exhibited narrow size distribution, high emission intensity, and few native defects. Scale-up and emission tunability using copper-doping were confirmed spectroscopically. Surface characterization was determined using Fourier transform infrared and X-ray photoelectron spectroscopies, which confirmed amine and carboxylic acid not only maintaining a nano-dimensional average crystallite size, but also increasing aggregation. Application of ZnS nanoparticle ink to a functional thin film was successfully tested for potential future applications.

Moon, Ji Won [ORNL; Ivanov, Ilia N [ORNL; Joshi, Pooran C [ORNL; Armstrong, Beth L [ORNL; Wang, Wei [ORNL; Jung, Hyunsung [ORNL; Rondinone, Adam Justin [ORNL; Jellison Jr, Gerald Earle [ORNL; Meyer III, Harry M [ORNL; Jang, Gyoung Gug [Oak Ridge National Laboratory (ORNL); Meisner, Roberta [Oak Ridge National Laboratory (ORNL); Duty, Chad E [ORNL; Phelps, Tommy Joe [ORNL

2014-01-01T23:59:59.000Z

262

Study of hydrogen and carbon monoxide adsorption on modified Zn/Cr catalysts by adsorption calorimetry  

SciTech Connect (OSTI)

Differential heat of adsorption (q) of hydrogen (a) and carbon monoxide (b) as a function of the adsorbed amount (a) on Zn/Cr catalysts at 463/sup 0/K; 1) unpromoted catalyst, 2) catalyst promoted with 2.5% of K/sub 2/O.

Yoshin, S.V.; Klyacho, A.L.; Kondrat'ev, L.T.; Leonov, V.E.; Skripchenko, G.B.; Sushchaya, L.E.

1986-08-01T23:59:59.000Z

263

Fabrication of inverted opal ZnO photonic crystals by atomic layer deposition  

E-Print Network [OSTI]

Fabrication of inverted opal ZnO photonic crystals by atomic layer deposition M. Scharrer, X. Wu, A method to fabricate so-called "inverted opal" structures which have the long-range order, high filling into opal or inverted opal backbones.3,5,13,14 Recently, atomic layer deposition ALD has been pro- posed

Cao, Hui

264

Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method  

SciTech Connect (OSTI)

ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

2014-02-24T23:59:59.000Z

265

Acceptors in ZnO nanocrystals: A reinterpretation W. Gehlhoff and A. Hoffmann  

E-Print Network [OSTI]

et al. reported on the identification of an uncompensated acceptor in ZnO nanocrystals using infrared and valence band splitting. VC 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773524] Bulk. Recently, Teklemichael, Hlaing Oo, McCluskey et al.5 (THC) reported on the identification

Nabben, Reinhard

266

Nondestructive In Situ Identification of Crystal Orientation of Anisotropic ZnO  

E-Print Network [OSTI]

Nondestructive In Situ Identification of Crystal Orientation of Anisotropic ZnO Nanostructures to their unique mechanical, electrical, and optical proper- ties compared to their bulk counterparts.1 4 Important, a fast, unambiguous, and nondestructive technique for identification of the crystalline orientation

Wang, Zhong L.

267

ZnO nanoparticles and nanowire array hybrid photoanodes for dye-sensitized solar cells  

E-Print Network [OSTI]

ZnO nanoparticles and nanowire array hybrid photoanodes for dye-sensitized solar cells Supan for dye-sensitized solar cell DSC with NW arrays to serve as a direct pathway for fast electron transport Institute of Physics. doi:10.1063/1.3327339 Dye-sensitized solar cells DSCs have attracted a lot

Cao, Guozhong

268

Sonochemically grown ZnO nanowalls on Graphene layers as Photoanode in Dye sensitized Solar cells.  

E-Print Network [OSTI]

Sonochemically grown ZnO nanowalls on Graphene layers as Photoanode in Dye sensitized Solar cells whole solar spectrum Graphene can be a very promising material in Dye Sensitized Solar cells (DSSC as photoanode is presented. The effect of Graphene on dye loading and on efficiency of DSSC is quantitatively

Pala, Nezih

269

RESEARCH ARTICLE Additional coating effects on textured ZnO : Al thin  

E-Print Network [OSTI]

Laboratory, LG Electronics, Seoul 137724, Korea ABSTRACT ZnO : Al films were additionally deposited, Devices and Materials Laboratory, LG Electronics, Seoul 137724, Korea. Email: taeho78@korea.ac.kr Received reported using transmission electron microscopy or scanning electron microscopy [4,6,7]. However, when

Park, Byungwoo

270

Hierarchically Structured ZnO Nanorods-Nanosheets for Improved Quantum-Dot-Sensitized Solar Cells  

E-Print Network [OSTI]

). This hierarchical structure had two advantages in improving the power conversion efficiency (PCE) of the solar cells. INTRODUCTION The establishment of low-cost and high-performance solar cells for sustainable energy sourcesHierarchically Structured ZnO Nanorods-Nanosheets for Improved Quantum-Dot-Sensitized Solar Cells

Cao, Guozhong

271

Microstructured porous ZnO thin film for increased light scattering and improved  

E-Print Network [OSTI]

for enhancing light scattering and efficiency in inverted organic photovoltaics. High degree of porosity. References and links 1. S. R. Forrest, "The limits to organic photovoltaic cell efficiency," MRS Bull. 30Microstructured porous ZnO thin film for increased light scattering and improved efficiency

Demir, Hilmi Volkan

272

A self-powered piezotronic strain sensor based on single ZnSnO3 microbelts  

E-Print Network [OSTI]

to a polyethylene terephthalate (PET) substrate to fabricate a strain sensor and a single-nanobelt nanogenerator, the production and disposal of current designs can produce non-recyclable garbage that contains toxic heavy terephthalate (PET) substrate. Due to a spontaneous polarization that is generated along the z-axis in ZnSnO3

Wang, Zhong L.

273

Hydrogen at zinc vacancy of ZnO: An EPR and ESEEM study  

SciTech Connect (OSTI)

An electron paramagnetic resonance (EPR) spectrum, labeled S1, with small-splitting doublet accompanied by weak satellites is observed in ZnO irradiated with 2 MeV electrons. The obtained structure is shown to be the hyperfine structure due to the dipolar interaction between an unpaired electron spin and a nuclear spin of hydrogen (H). The observation of the nuclear Zeeman frequency of H in electron spin echo envelope modulation experiments further confirmed the presence of a hydrogen atom in S1. From the observed spin-Hamiltonian parameters, S1 is identified to be the partly H-passivated Zn vacancy, V{sub Zn}{sup ?}H{sup +}, with the H{sup +} ion making a short O-H bond with only one nearest O neighbor of V{sub Zn} in the basal plane, being off the substitutional site, while the unpaired electron spin, which gives rise to the observed EPR signal, is localized on the p orbital of another O neighbor also in the basal plane.

Son, N. T.; Ivanov, I. G.; Janzn, E. [Department Physics, Chemistry and Biology, Linkping University, SE-58183 Linkping (Sweden); Isoya, J. [Graduate School of Library, Information and Media Studies, University of Tsukuba, Tsukuba, Ibaraki 305-8550 (Japan); Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

2014-02-21T23:59:59.000Z

274

Growth of vertically aligned ZnO nanowalls for inverted polymer solar cells  

E-Print Network [OSTI]

Growth of vertically aligned ZnO nanowalls for inverted polymer solar cells Zhiqiang Liang a,n a School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001, PR China b May 2013 Keywords: Inverted polymer solar cells Zinc oxide Nanowalls Aqueous solution growth a b s t r

Cao, Guozhong

275

Bandgap engineering of CdxZn1xTe nanowires Keivan Davami,a  

E-Print Network [OSTI]

junction. These structures have been used in solar cells2,3 and eld effect transistors.4 Alloy nanowires device fabrication. Alloy nano- wires in various systems have been used to construct solar cells into a furnace. In a set of trial experiments, ZnTe (99.99% Aldrich) and CdTe (99.99% Aldrich) source powders

Cuniberti, Gianaurelio

276

Crystallographic Orientation-Aligned ZnO Nanorods Grown by a Tin Catalyst  

E-Print Network [OSTI]

, has a wide range of applications in solar cells,1 sensors,2-4 optoelectronic devices, and surface a horizontal tube furnace, a rotary pump system, and a gas supply system. A mixture of commercial ZnO, SnO2). The entire length of the tube furnace is 50 cm. The desired nanostruc- tures were deposited onto an alumina

Wang, Zhong L.

277

Interpenetrative and transverse growth process of self-catalyzed ZnO nanorods  

E-Print Network [OSTI]

for short-wavelength optoelectronics [1] and transparent con- ducting windows for solar cells [2 evaporation process in a horizontal tube furnace. Commercial grade ZnO powder was place in the center of a single zone tube furnace and evacuated for several hours to purge oxygen in the chamber. Polycrystalline

Wang, Zhong L.

278

Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral)  

E-Print Network [OSTI]

Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral) Authors: E.F. Peltier* - Univ. of Delaware D.L. Sparks - Univ. of Delaware Abstract: The formation matter in the soil. Speaker Information: Edward Peltier, Univ. of Delaware, Dept. of Plant and Soil

Sparks, Donald L.

279

Double Direct Templating of Periodically Nanostructured ZnS Hollow Microspheres  

E-Print Network [OSTI]

Double Direct Templating of Periodically Nanostructured ZnS Hollow Microspheres Alejandro Wolosiuk 61801 Received July 22, 2005; E-mail: pbraun@uiuc.edu Hollow capsules are both technologically and scientifically interesting. "Smart" nano- and microcontainers could lead new catalysts, structures

Braun, Paul

280

Cu2ZnSnS4 nanocrystals and graphene quantum dots for photovoltaics Xukai Xinab  

E-Print Network [OSTI]

Cu2ZnSnS4 nanocrystals and graphene quantum dots for photovoltaics Jun Wang,a Xukai Xinab advances in the synthesis and utilization of CZTS nanocrystals and colloidal GQDs for photovoltaics emerged to achieve low cost, high perfor- mance photovoltaics, including organic solar cells,26 dye

Lin, Zhiqun

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

MOCVD growth mechanisms of ZnO nanorods G Perillat-Merceroz1, 2  

E-Print Network [OSTI]

cells, gas sensors or LEDs. Their high crystalline quality and purity, due to growth without a catalyst, are adequate for optoelectronic applications. MOCVD growth [2] enables fast, large area deposition details ZnO nanorods were grown using catalyst-free MOCVD in a horizontal hot-wall Epigress reactor. The c

Boyer, Edmond

282

Hydrothermal Synthesis and Structural Characterization of Novel Zn-Triazole-Benzenedicarboxylate Frameworks  

SciTech Connect (OSTI)

Three new metal-organic coordination polymers were synthesized hydrothermally using Zn2+ ion, 1,2,4-triazole, and 1,4-benzenedicarboxylic acid (BDC): Zn5(H2O)2(C2H2N3)4(C8H4O4)3 {center_dot} 3.9H2O (1), Zn2(C2H2N3)2(C2H3N3)(C8H4O4) {center_dot} 2.5H2O (2), and Zn4(H2O)2(C2H2N3)4(C8H4O4)2 {center_dot} 14H2O (3). Their crystal structures were determined by single-crystal X-ray diffraction. Their thermal properties were examined by thermogravimetric analysis. Structure 1 crystallizes in the monoclinic P21/n space group with a = 10.192(2) {angstrom}, b = 17.764(4) {angstrom}, c = 24.437(5) {angstrom}, {beta} = 91.19(3){sup o}, and V = 4423.3(15) {angstrom}3. Structure 2 crystallizes in the triclinic P space group with a = 7.797(2) {angstrom}, b = 10.047(2) {angstrom}, c = 13.577(3) {angstrom}, {alpha} = 110.18(3){sup o}, {beta} = 105.46(3){sup o}, {gamma} = 93.90(3){sup o}, and V = 947.0(3) {angstrom}3. Structure 3 crystallizes in monoclinic P21/n space group with a = 13.475(3) {angstrom}, b = 26.949(5) {angstrom}, c = 13.509(3) {angstrom}, {beta} = 95.18(3){sup o}, and V = 4885.7(17) {angstrom}3. In structure 1, the units of the triazole-Zn polyhedra are linked by BDC in a zigzag fashion to create the stacking of phenyl groups along the a axis. In structure 2, both triazole and BDC bridge Zn polyhedra in the (011) plane, resulting in the eight-membered channels along the a axis. In the case of structure 3, the BDC links the Zn polyhedra along the b axis to form a pillared open framework. This structure is the most porous of the compounds presented in this work.

Park, Hyunsoo; Moureau, David M.; Parise, John B. (SBU)

2008-10-03T23:59:59.000Z

283

Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals  

SciTech Connect (OSTI)

Highlights: ? Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ? From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ? Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ? The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

Tripathi, S.K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India); Sharma, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India)

2013-05-15T23:59:59.000Z

284

Single-step in-situ synthesis and optical properties of ZnSe nanostructured dielectric nanocomposites  

SciTech Connect (OSTI)

This work provides the evidence of visible red photoluminescent light emission from ZnSe nanocrystals (NCs) grown within a dielectric (borosilicate glass) matrix synthesized by a single step in-situ technique for the first time and the NC sizes were controlled by varying only the concentration of ZnSe in glass matrix. The ZnSe NCs were investigated by UV-Vis optical absorption spectroscopy, Raman spectroscopy, and transmission electron microscopy (TEM). The sizes of the ZnSe NCs estimated from the TEM images are found to alter in the range of 253?nm. Their smaller sizes of the NCs were also calculated by using the optical absorption spectra and the effective mass approximation model. The band gap enlargements both for carrier and exciton confinements were evaluated and found to be changed in the range of 01.0?eV. The Raman spectroscopic studies showed blue shifted Raman peaks of ZnSe at 295 and 315?cm{sup ?1} indicating phonon confinement effect as well as compressive stress effect on the surface atoms of the NCs. Red photoluminescence in ZnSe-glass nanocomposite reveals a broad multiple-peak structure due to overlapping of emission from NC size related electron-hole recombination (?707?nm) and emissions from defects to traps, which were formed due to Se and Zn vacancies signifying potential application in photonics.

Dey, Chirantan; Rahaman Molla, Atiar; Tarafder, Anal; Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [CSIR-Central Glass and Ceramic Research Institute, Glass Science and Technology Section, Glass Division, 196, Raja S. C. Mullick Road, 700032 Kolkata (India); Kr Mishra, Manish; De, Goutam [CSIR-Central Glass and Ceramic Research Institute, Nano-Structured Materials Division, 196, Raja S. C. Mullick Road, 700032 Kolkata (India); Goswami, Madhumita; Kothiyal, G. P. [Glass and Advanced Ceramics Division, Bhaba Atomic Research Centre, Trombay, 400085 Mumbai (India)

2014-04-07T23:59:59.000Z

285

Electrodeposition and room temperature ferromagnetic anisotropy of Co and Ni-doped ZnO nanowire arrays  

SciTech Connect (OSTI)

Cobalt and nickel doped ZnO nanowire arrays were synthesized by an electrochemical process at a temperature of 90 deg. C. Energy dispersive x-ray spectroscopy and x-ray diffraction show that the dopants are incorporated into the wurtzite-structure ZnO. Anisotropic ferromagnetism with an easy direction of magnetization either perpendicular or parallel to the wire axis, depending on the wire geometry and density, was observed in 1.7% Co and 2.2% Ni-doped ZnO nanowires at room temperature. The anisotropic magnetism was explained in terms of a competition between self-demagnetization and magnetostatic coupling among the nanowires.

Cui, J.B.; Gibson, U.J. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755-8000 (United States)

2005-09-26T23:59:59.000Z

286

Zn-Doping Dependence of Stripe Order in La1.905Ba0.095CuO4  

SciTech Connect (OSTI)

The effect of Zn-doping on the stripe order in La{sub 1.905}Ba{sub 0.095}CuO{sub 4} has been studied by means of x-ray and neutron diffraction as well as magnetization measurements. While 1% Zn leads to an increase of the spin stripe order, it unexpectedly causes a wipe out of the visibility of the charge stripe order. A magnetic field of 10 Tesla applied along the c-axis has no reversing effect on the charge order. We compare this observation with the Zn-doping dependence of the crystal structure, superconductivity, and normal state magnetism.

Hucker, M.; Zimmermann, M.v.; Xu, Z.J.; Wen, J.S.; Gu, G.D.; Tian, W.; Zarestky, J.; Tranquada, J.M.

2011-04-01T23:59:59.000Z

287

Magnetic field induced third order susceptibility of third order harmonic generation in a ZnMgSe strained quantum well  

SciTech Connect (OSTI)

Third order susceptibility of third order harmonic generation is investigated in a Zn{sub 0.1}Mg{sub 0.9}Se/Zn{sub 0.8}Mg{sub 0.2}Se/Zn{sub 0.1}Mg{sub 0.9}Se quantum well in the presence of magnetic field strength. The confinement potential is considered as the addition of energy offsets of the conduction band (or valence band) and the strain-induced potential in our calculations. The material dependent effective mass is followed throughout the computation because it has a high influence on the electron energy levels in low dimensional semiconductor systems.

Mark, J. Abraham Hudson, E-mail: a.john.peter@gmail.com; Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, SSM Institute of Engineering and Technology, Dindigul-624002 (India)

2014-04-24T23:59:59.000Z

288

Use of separate ZnTe interface layers to form OHMIC contacts to p-CdTe films  

DOE Patents [OSTI]

A method of improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurim-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact.

Gessert, Timothy A. (Conifer, CO)

1999-01-01T23:59:59.000Z

289

Localization of Competing Metals (Ni, Co, and Zn) in Alyssum using micro-XRF and Tomography. (3564)  

E-Print Network [OSTI]

Localization of Competing Metals (Ni, Co, and Zn) in Alyssum using micro-XRF and Tomography. (3564 and observed metal localization in root and shoot tissue using synchrotron based micro-XRF and tomography

Sparks, Donald L.

290

Use of separate ZnTe interface layers to form ohmic contacts to p-CdTe films  

DOE Patents [OSTI]

A method of is disclosed improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurium-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact. 11 figs.

Gessert, T.A.

1999-06-01T23:59:59.000Z

291

Origin of ultraviolet photoluminescence in ZnO quantum dots: Confined excitons versus surface-bound impurity exciton complexes  

E-Print Network [OSTI]

sources of PL. © 2004 American Institute of Physics. [DOI: 10.1063/1.1835992] Zinc oxide (ZnO) has diodes, laser diodes, varistors, and transparent con- ducting films. Compared to other wide band

Fonoberov, Vladimir

292

Band structure engineering for solar energy applications: ZnO1-xSex films and devices  

E-Print Network [OSTI]

W. Walukiewicz, and J. Wu, Solar Energy Materials and Solarand M. J. Carter, Solar Energy Materials and Solar Cells 51,structure engineering for solar energy applications: ZnO 1-x

Mayer, Marie Annette

2012-01-01T23:59:59.000Z

293

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition  

SciTech Connect (OSTI)

We report a breakthrough in fabricating ZnO homojunction light-emitting diode by metal organic chemical vapor deposition. Using NO plasma, we are able to grow p-type ZnO thin films on n-type bulk ZnO substrates. The as-grown films on glass substrates show hole concentration of 10{sup 16}-10{sup 17} cm{sup -3} and mobility of 1-10 cm{sup 2} V{sup -1} s{sup -1}. Room-temperature photoluminescence spectra reveal nitrogen-related emissions. A typical ZnO homojunction shows rectifying behavior with a turn-on voltage of about 2.3 V. Electroluminescence at room temperature has been demonstrated with band-to-band emission at I=40 mA and defect-related emissions in the blue-yellow spectrum range.

Xu, W.Z.; Ye, Z.Z.; Zeng, Y.J.; Zhu, L.P.; Zhao, B.H.; Jiang, L.; Lu, J.G.; He, H.P.; Zhang, S.B. [State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

2006-04-24T23:59:59.000Z

294

Fast Response and High Sensitivity ZnO/glass Surface Acoustic Wave Humidity Sensors Using Graphene Oxide Sensing Layer  

E-Print Network [OSTI]

We report ZnO/glass surface acoustic wave (SAW) humidity sensors with high sensitivity and fast response using graphene oxide sensing layer. The frequency shift of the sensors is exponentially correlated to the humidity change, induced mainly...

Xuan, Weipeng; He, Mei; Meng, Nan; He, Xingli; Wang, Wenbo; Chen, Jinkai; Shi, Tianjin; Hasan, Tawfique; Xu, Zhen; Xu, Yang; Luo, J. K.

2014-11-26T23:59:59.000Z

295

Band offsets for mismatched interfaces: The special case of ZnO on CdTe (001)  

SciTech Connect (OSTI)

High-quality planar interfaces between ZnO and CdTe would be useful in optoelectronic applications. Although CdTe is zinc blende with cubic lattice constant a = 6.482 while ZnO is hexagonal wurtzite with a = 3.253 and c = 5.213 , (001)-oriented cubic zinc blende ZnO films could be stabilized epitaxially on a CdTe (001) surface in an ?2 ?2 R45 configuration with a lattice mismatch of <0.5%. Modeling such a configuration allows density-functional total-energy electronic-structure calculations to be performed on several interface arrangements (varying terminations and in-plane fractional translations) to identify the most likely form of the interface, and to predict valence-band offsets between CdTe and ZnO in each case. Growth of ZnO on Te-terminated CdTe(001) is predicted to produce small or even negative (CdTe below ZnO) valence band offsets, resulting in a Type I band alignment. Growth on Cd-terminated CdTe is predicted to produce large positive offsets for a Type II alignment as needed, for example, in solar cells. To corroborate some of these predictions, thin layers of ZnO were deposited on CdTe(001) by pulsed laser deposition, and the band alignments of the resulting heterojunctions were determined from x-ray photoelectron spectroscopy measurements. Although zinc blende ZnO could not be confirmed, the measured valence band offset (2.02.2 eV) matched well with the predicted value.

Jaffe, John E.; Kaspar, Tiffany C.; Droubay, Timothy C. [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)] [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States); Varga, Tamas [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)

2013-11-15T23:59:59.000Z

296

A green chemical approach to the synthesis of photoluminescent ZnO hollow spheres with enhanced photocatalytic properties  

SciTech Connect (OSTI)

ZnO hollow spheres have been synthesized by a simple and environmentally friendly template assisted route. Starch-derived carbonaceous spheres were used as template, impregnated with Zn(CH{sub 3}COO){sub 2}{center_dot}2H{sub 2}O to obtain zinc-containing precursor spheres and thermally treatment at 600 Degree-Sign C, yielding hollow ZnO spherical shells. The precursor spheres and hollow shells were characterized by X-ray diffraction, FTIR spectroscopy, scanning electron microscopy, thermal analysis and room-temperature photoluminescence measurements. The hollow spherical shells with diameters of {approx}150 nm and wall thickness of {approx}20 nm, are polycrystalline, with a mean crystallite size of 22 nm, exhibiting interesting emission features, with a wide multi-peak band covering blue and green regions of the visible spectrum. The photocatalytic activities (under UV and visible light irradiations) of the ZnO spherical shells evaluated for the phenol degradation reaction in aqueous solutions are outstanding, a total phenol conversion being registered in the case of UV irradiation experiments. - Graphical abstract: The photocatalytic reaction initiated by the photoexcitation of the semiconductor (ZnO), leads to the formation of electron-hole, while part of the electron-hole pairs recombine, some holes combine with water to form {center_dot}OH radicals and some electrons convert oxygen to super oxide radical ({center_dot}O{sub 2}{sup -}). Highlights: Black-Right-Pointing-Pointer Green synthesis of ZnO hollow spheres. Black-Right-Pointing-Pointer Starch-derived carbonaceous spheres as spherical hard template. Black-Right-Pointing-Pointer ZnO hollow spheres with notable visible photoluminescence properties. Black-Right-Pointing-Pointer ZnO hollow spheres with photocatalytical activity in degradation/mineralization of phenol.

Patrinoiu, Greta; Tudose, Madalina; Calderon-Moreno, Jose Maria ['Ilie Murgulescu' Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest (Romania); Birjega, Ruxandra [National Institute for Lasers, Plasma and Radiation Physics, P.O. BOX Mg-27, Magurele, Bucharest (Romania); Budrugeac, Petru [National Institute for Research and Development in Electrical Engineering, ICPE-CA, Advanced Research, Splaiul Unirii 313, 030138 Bucharest (Romania); Ene, Ramona ['Ilie Murgulescu' Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest (Romania); Carp, Oana, E-mail: ocarp@icf.ro ['Ilie Murgulescu' Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest (Romania)

2012-02-15T23:59:59.000Z

297

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells  

E-Print Network [OSTI]

A new methodology is proposed for finding structures that are, optically speaking, locally optimal : a physical analysis of much simpler structures is used to constrain the optimization process. The obtained designs are based on a flat amorphous silicon layer (to minimize recombination) with a patterned anti-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers.

Moreau, Antoine; Centeno, Emmanuel; Seassal, Christian

2012-01-01T23:59:59.000Z

298

Spectral photoresponse of ZnSe/GaAs(001) heterostructures with CdSe ultra-thin quantum well insertions  

SciTech Connect (OSTI)

We present a study of the spectral photoresponse (SPR) of ZnSe/GaAs(001) heterostructures for different ZnSe film thickness with and without CdSe ultra-thin quantum well (UTQW) insertions. We observe a significant increase of the SPR of heterostructures containing 3 monolayer thick CdSe UTQW insertions; these results encourage their use in photodetectors and solar cells.

Valverde-Chvez, D. A.; Sutara, F.; Hernndez-Caldern, I. [Physics Department, Cinvestav-IPN, Av. IPN 2508, 07360 Mxico, DF (Mexico)

2014-05-15T23:59:59.000Z

299

Blueshift of optical band gap in ZnO thin films grown by metal-organic chemical-vapor deposition  

E-Print Network [OSTI]

. INTRODUCTION Zinc oxide ZnO is a wide direct band-gap 3.37 eV semiconductor with a broad range of applications. Dimethylzinc DMZn , N2 gas, and high-purity O2 were used as the zinc source, carrier gas, and oxidizing agent including light-emitting devices,1 varistors,2 solar cells,3 and gas sensors.4 Moreover, ZnO is a promising

300

Structural study and phase transition investigation in a simple synthesis of porous architected-ZnO nanopowder  

SciTech Connect (OSTI)

In this work, zinc oxide powder with a rectangular-shaped porous architecture, made of numerous spherical nanometric particles, was obtained. A simple precipitation/decomposition procedure was used comprising a zinc oxalate intermediate, obtained from zinc sulfate and oxalic acid without any additives. Detailed studies on zinc oxalate dehydration, decomposition and zinc oxide formation, were carried out using in-situ temperature X-ray diffraction and thermogravimetric analysis. During the investigation, the temperature dependence of particle sizes, lattice parameters and crystal structures of ZnC{sub 2}O{sub 4}2H{sub 2}O, ZnC{sub 2}O{sub 4} and ZnO nanopowders were analyzed from room temperature to 450 C. Structural transitions were also discussed. The structure and morphology of the as-prepared ZnO nanopowder were investigated by electron microscopy and compared to the crystalline rectangular shape of ZnC{sub 2}O{sub 4}2H{sub 2}O. The calcination temperature, counter ion and precipitate agent were found to be related to the product's shape and diameter. Spherical ZnO nanoparticles with diameters of less than 20 nm and a maximum specific surface of 53 m{sup 2}/g were obtained using this method. Highlights: ZnO nanopowders with porous architecture were synthesized by a simple method. Spherical ZnO nanoparticles confined in submicronic rectangular shape are obtained. Crystal structures are determined temperature in-situ XRD up to 450 C. Structural transitions were analyzed.

Shang, C.; Barnab, A., E-mail: barnabe@chimie.ups-tlse.fr

2013-12-15T23:59:59.000Z

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301

Prolactin receptor attenuation induces zinc pool redistribution through ZnT2 and decreases invasion in MDA-MB-453 breast cancer cells  

SciTech Connect (OSTI)

Prolactin receptor (PRL-R) activation regulates cell differentiation, proliferation, cell survival and motility of breast cells. Prolactin (PRL) and PRL-R over-expression are strongly implicated in breast cancer, particularly contributing to tumor growth and invasion in the more aggressive estrogen-receptor negative (ER?) disease. PRL-R antagonists have been suggested as potential therapeutic agents; however, mechanisms through which PRL-R antagonists exert their actions are not well-understood. Zinc (Zn) is a regulatory factor for over 10% of the proteome, regulating critical cell processes such as proliferation, cell signaling, transcription, apoptosis and autophagy. PRL-R signaling regulates Zn metabolism in breast cells. Herein we determined effects of PRL-R attenuation on cellular Zn metabolism and cell function in a model of ER-, PRL-R over-expressing breast cancer cells (MDA-MB-453). PRL-R attenuation post-transcriptionally increased ZnT2 abundance and redistributed intracellular Zn pools into lysosomes and mitochondria. ZnT2-mediated lysosomal Zn sequestration was associated with reduced matrix metalloproteinase 2 (MMP-2) activity and decreased invasion. ZnT2-mediated Zn accumulation in mitochondria was associated with increased mitochondrial oxidation. Our results suggest that PRL-R antagonism in PRL-R over-expressing breast cancer cells may reduce invasion through the redistribution of intracellular Zn pools critical for cellular function. - Highlights: PRL-R attenuation increased ZnT2 expression. PRL-R attenuation increased lysosomal and mitochondrial Zn accumulation. PRL-R attenuation decreased MMP-2 and invasion. PRL-R antagonists may modulate lysosomal and mitochondrial Zn pools.

Bostanci, Zeynep, E-mail: zbostanci@hmc.psu.edu [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); Alam, Samina, E-mail: sra116@psu.edu [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); Soybel, David I., E-mail: dsoybel@hmc.psu.edu [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); The Pennsylvania State University College of Medicine, Department of Cell and Molecular Physiology, 500 University Dr., Hershey, PA 17033 (United States); Kelleher, Shannon L., E-mail: slk39@psu.edu [The Pennsylvania State University, Department of Nutritional Sciences, 209 Chandlee Lab, University Park, PA 16802 (United States); The Pennsylvania State University Milton S. Hershey Medical Center, Department of Surgery, 500 University Dr., Hershey, PA 17033 (United States); The Pennsylvania State University College of Medicine, Department of Cell and Molecular Physiology, 500 University Dr., Hershey, PA 17033 (United States)

2014-02-15T23:59:59.000Z

302

On quantitative analysis of interband recombination dynamics: Theory and application to bulk ZnO  

SciTech Connect (OSTI)

The issue of the quantitative analysis of time-resolved photoluminescence experiments is addressed by developing and describing two approaches for determination of unimolecular lifetime, bimolecular recombination coefficient, and equilibrium free-carrier concentration, based on a quite general second-order expression of the electron-hole recombination rate. Application to the case of band-edge emission of ZnO single crystals is reported, evidencing the signature of sub-nanosecond second-order recombination dynamics for optical transitions close to the interband excitation edge. The resulting findings are in good agreement with the model prediction and further confirm the presence, formerly evidenced in literature by non-optical methods, of near-surface conductive layers in ZnO crystals with sheet charge densities of about 3510{sup 13} cm{sup ?2}.

Lettieri, S. [Institute for Superconductors, Oxides and Innovative Materials, National Research Council (CNR-SPIN), U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy)] [Institute for Superconductors, Oxides and Innovative Materials, National Research Council (CNR-SPIN), U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy); Capello, V.; Santamaria, L. [Physics Department, University of Naples Federico II, Via Cintia I-80126 Napoli (Italy)] [Physics Department, University of Naples Federico II, Via Cintia I-80126 Napoli (Italy); Maddalena, P. [Institute for Superconductors, Oxides and Innovative Materials, National Research Council (CNR-SPIN), U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy) [Institute for Superconductors, Oxides and Innovative Materials, National Research Council (CNR-SPIN), U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy); Physics Department, University of Naples Federico II, Via Cintia I-80126 Napoli (Italy)

2013-12-09T23:59:59.000Z

303

Phase assembly and photo-induced current in CdTe-ZnO nanocomposite thin films  

SciTech Connect (OSTI)

Sequential radio-frequency sputtering was used to produce CdTe-ZnO nanocomposite thin films with varied semiconductor-phase extended structures. Control of the spatial distribution of CdTe nanoparticles within the ZnO embedding phase was used to influence the semiconductor phase connectivity, contributing to both changes in quantum confinement induced spectral absorption and carrier transport characteristics of the resulting nanocomposite. An increased number density of CdTe particles deposited along the applied field direction produced an enhancement in the photo-induced current observed. These results highlight the opportunity to employ long-range phase assembly as a means to control optoelectronic properties of significant interest for photovoltaic applications.

Beal, R. J.; Kana Kana, J. B. [Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721 (United States); Potter, B. G. Jr. [Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States)

2012-07-16T23:59:59.000Z

304

ZnO buffer layer for metal films on silicon substrates  

DOE Patents [OSTI]

Dramatic improvements in metallization integrity and electroceramic thin film performance can be achieved by the use of the ZnO buffer layer to minimize interfacial energy between metallization and adhesion layers. In particular, the invention provides a substrate metallization method utilizing a ZnO adhesion layer that has a high work of adhesion, which in turn enables processing under thermal budgets typically reserved for more exotic ceramic, single-crystal, or metal foil substrates. Embodiments of the present invention can be used in a broad range of applications beyond ferroelectric capacitors, including microelectromechanical systems, micro-printed heaters and sensors, and electrochemical energy storage, where integrity of metallized silicon to high temperatures is necessary.

Ihlefeld, Jon

2014-09-16T23:59:59.000Z

305

Electrodeposition of corrosion-resistant Ni-Zn alloy. I. Cyclic voltammetric study  

SciTech Connect (OSTI)

The interaction between different reacting species involved in the initial stage of electrodeposition of nickel-zinc alloy was investigated. A cyclic voltammetric study indicates that codeposition of hydrogen and nickel occurs, with formation of two types of hydrogen-nickel solid solution, i.e., [beta]-Ni and [alpha]-Ni. This nickel hydride formation during Ni-Zn alloy electrodeposition was verified by analyzing the voltammograms of nickel, zinc, and Ni-Zn alloy during initial deposition on various substrates. The dissolution potential of zinc and nickel from electrodeposited nickel-zinc alloy spans a wide range (ca. 400 mV). The influence of the interaction between nickel, hydrogen, and zinc on the nucleation of nickel-zinc electrodeposition is reported in part II of this paper.

Lin, Yu-Po; Selman, J.R. (Illinois Inst. of Technology, Chicago (United States))

1993-05-01T23:59:59.000Z

306

Soil and Mold Influences on Fe and Zn Concentrations of Sorghum Grain in Mali, West Africa  

E-Print Network [OSTI]

+ from soil and DTPA similarly complexes these labile forms. Several recent studies involving crops other than sorghum have shown that the concentration of Fe and Zn in the grain does not always consistently reflect DTPA- extractable Fe and Zn...) 22.6 (18.4) 6.60 (3.99) 2.16 (1.20) 15-30 5.96 (0.54) 0.13 (0.13) 0.69 (0.15) 533 (89.9) -- 5.43 (1.44) 0.95 (0.55) Tiguere Field 1 0-15 6.24 (0.58) -- 1.33 (0.08) 590 (54.6) 12.8 (5.7) 7.75 (4.28) 2.78 (1.77) 15-30 5.61 (0...

Verbree, Cheryl

2012-10-19T23:59:59.000Z

307

Microstructural and optical studies on sonochemically synthesized Cu doped ZnO nanoparticles  

SciTech Connect (OSTI)

Copper doped ZnO nanoparticles were synthesized by sonochemical method varying the concentration of the impurity. Systematic investigations like X-ray diffraction (XRD) and Transmission electron microscopy (TEM) were carried out to understand the microstructural properties. The average particle sizes and all the crystallographic parameters were calculated from XRD results. This shows the formation of wurtzite phase of ZnO with average size of the particles as 53 nm and an increase of particle size with dopant concentration was also been observed. UV absorption and Fourier transformed infrared spectroscopy (FTIR) spectra revealed the absorption at wavelength < 370 nm with a remarkable red shift of absorption band and a linear decrease of transmittance with increase in doping concentrations respectively.

Sahu, Dojalisa, E-mail: dojalisa.sahu@gmail.com; Panda, Nihar Ranjan, E-mail: dojalisa.sahu@gmail.com; Panda, A. K. [Sambalpur University, Jyoti Vihar, Burla -768019, Odisha (India); Acharya, B. S. [C.V. Raman College of Engineering, Bhubaneswar-752054, Odisha (India)

2014-04-24T23:59:59.000Z

308

Changes induced in a ZnS:Cr-based electroluminescent waveguide structure by intrinsic near-infrared laser radiation  

SciTech Connect (OSTI)

The causes of changes that occur in a thin-film electroluminescent metal-insulator-semiconductor-insulator-metal waveguide structure based on ZnS:Cr (Cr concentration of {approx}4 Multiplication-Sign 10{sup 20} cm{sup -3}) upon lasing ({lambda} Almost-Equal-To 2.6 {mu}m) and that induce lasing cessation are studied. It is established that lasing ceases because of light-scattering inhomogeneities formed in the structure and, hence, optical losses enhance. The origin of the inhomogeneities and the causes of their formation are clarified by studying the surface topology and the crystal structure of constituent layers of the samples before and after lasing. The studies are performed by means of atomic force microscopy and X-ray radiography. It is shown that a substantial increase in the sizes of grains on the surface of the structure is the manifestation of changes induced in the ZnS:Cr film by recrystallization. Recrystallization is initiated by local heating by absorbed laser radiation in existing Cr clusters and quickened by a strong electric field (>1 MV cm{sup -1}). The changes observed in the ZnS:Cr film are as follows: the textured growth of ZnS crystallites, an increase in the content of Cr clusters, and the appearance of some CrS and a rather high ZnO content. Some ways for improving the stability of lasing in the ZnS:Cr-based waveguide structures are proposed.

Vlasenko, N. A., E-mail: vlasenko@isp.kiev.ua; Oleksenko, P. F.; Mukhlyo, M. A.; Veligura, L. I. [National Academy of Sciences of Ukraine, Lashkarev Institute of Semiconductor Physics (Ukraine)] [National Academy of Sciences of Ukraine, Lashkarev Institute of Semiconductor Physics (Ukraine)

2013-08-15T23:59:59.000Z

309

Point Defects in CdZnTe Crystals Grown by Different Techniques  

SciTech Connect (OSTI)

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps energies and densities.

R Gul; A Bolotnikov; H Kim; R Rodriguez; K Keeter; Z Li; G Gu; R James

2011-12-31T23:59:59.000Z

310

Point Defects in CdZnTe Crystals Grown by Different Techniques  

SciTech Connect (OSTI)

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps energies and densities.

Gul, R.; Bolotnikov, A.; Kim, H.K.; Rodriguez, R.; Keeter, K.; Li, Z.; Gu, G.; and James, R.B.

2011-02-02T23:59:59.000Z

311

New ZnO-Based Regenerable Sulfur Sorbents for Fluid-Bed/Transport Reactor Applications  

SciTech Connect (OSTI)

The overall objective of the ongoing sorbent development work at GTI is the advancement to the demonstration stage of a promising ZnO-TiO2 sulfur sorbent that has been developed under DCCA/ICCI and DOE/NETL sponsorship. This regenerable sorbent has been shown to possess an exceptional combination of excellent chemical reactivity, high effective capacity for sulfur absorption, high resistance to attrition, and regenerability at temperatures lower than required by typical zinc titanates.

Slimane, R.B.; Lau, F.S.; Abbasian, J.; Ho, K.H.

2002-09-19T23:59:59.000Z

312

Optically pumped quantum-dot Cd(Zn)Se/ZnSe laser and microchip converter for yellow-green spectral region  

SciTech Connect (OSTI)

The room temperature laser generation in the yellow-green ({lambda} = 558.5-566.7 nm) spectral range has been demonstrated under optical pumping by a pulsed nitrogen laser of Cd(Zn)Se/ZnSe quantum dot heterostructures. The maximum achieved laser wavelength was as high as {lambda} = 566.7 nm at a laser cavity length of 945 {mu}m. High values of both the output pulsed power (up to 50 W) and the external differential quantum efficiency ({approx}60%) were obtained at a cavity length of 435 {mu}m. Both a high quality of the laser heterostructure and a low lasing threshold ({approx}2 kW cm{sup -2}) make it possible to use a pulsed InGaN laser diode as a pump source. A laser microchip converter based on this heterostructure has demonstrated a maximum output pulse power of {approx}90 mW at {lambda} = 560 nm. The microchip converter was placed in a standard TO-18 (5.6 mm in diameter) laser diode package. (semiconductor lasers. physics and technology)

Lutsenko, E V; Voinilovich, A G; Rzheutskii, N V; Pavlovskii, V N; Yablonskii, G P; Sorokin, S V; Gronin, S V; Sedova, I V; Kop'ev, Petr S; Ivanov, Sergei V; Alanzi, M; Hamidalddin, A; Alyamani, A

2013-05-31T23:59:59.000Z

313

Effect of compressive stress on stability of N-doped p-type ZnO  

SciTech Connect (OSTI)

Nitrogen-doped p-type zinc oxide (p-ZnO:N) thin films were fabricated on a-/c-plane sapphire (a-/c-Al{sub 2}O{sub 3}) by plasma-assisted molecular beam epitaxy. Hall-effect measurements show that the p-type ZnO:N on c-Al{sub 2}O{sub 3} degenerated into n-type after a preservation time; however, the one grown on a-Al{sub 2}O{sub 3} showed good stability. The conversion of conductivity in the one grown on c-Al{sub 2}O{sub 3} ascribed to the faster disappearance of N{sub O} and the growing N{sub 2(O)}, which is demonstrated by x-ray photoelectron spectroscopy (XPS). Compressive stress, caused by lattice misfit, was revealed by Raman spectra and optical absorption spectra, and it was regarded as the root of the instability in ZnO:N.

Chen Xingyou [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Dongnanhu Road, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhang Zhenzhong; Jiang Mingming; Wang Shuangpeng; Li Binghui; Shan Chongxin; Liu Lei; Zhao Dongxu; Shen Dezhen [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Dongnanhu Road, Changchun 130033 (China); Yao Bin [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China)

2011-08-29T23:59:59.000Z

314

Rejection of randomly coinciding events in ZnMoO$_4$ scintillating bolometers  

E-Print Network [OSTI]

Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and $\\chi^2$ methods was applied to discriminate randomly coinciding events in ZnMoO$_4$ cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99% by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92% by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95% of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of $^{100}$Mo for enriched ZnMoO$_4$ detectors, of the order of $10^{-4}$ counts/(y keV kg). Pulse-shape parameters have been chosen on the basis of the performance of a real massive ZnMoO$_4$ scintillating bolometer. Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed.

D. M. Chernyak; F. A. Danevich; A. Giuliani; M. Mancuso; C. Nones; E. Olivieri; M. Tenconi; V. I. Tretyak

2014-04-04T23:59:59.000Z

315

ZnMoO4: a promising bolometer for neutrinoless double beta decay searches  

E-Print Network [OSTI]

We investigate the performances of two ZnMoO4 scintillating crystals operated as bolometers, in view of a next generation experiment to search the neutrinoless double beta decay of Mo-100. We present the results of the alpha vs beta/gamma discrimination, obtained through the scintillation light as well as through the study of the shape of the thermal signal alone. The discrimination capability obtained at the 2615 keV line of Tl-208 is 8 sigma, using the heat-light scatter plot, while it exceeds 20 sigma using the shape of the thermal pulse alone. The achieved FWHM energy resolution ranges from 2.4 keV (at 238 keV) to 5.7 keV (at 2615 keV). The internal radioactive contaminations of the ZnMoO4 crystals were evaluated through a 407 hours background measurement. The obtained limit is < 32 microBq/kg for Th-228 and Ra-226. These values were used for a Monte Carlo simulation aimed at evaluating the achievable background level of a possible, future array of enriched ZnMoO4 crystals.

J. W. Beeman; F. Bellini; S. Capelli; L. Cardani; N. Casali; I. Dafinei; S. Di Domizio; F. Ferroni; E. N. Galashov; L. Gironi; F. Orio; L. Pattavina; G. Pessina; G. Piperno; S. Pirro; V. N. Shlegel; Ya. V. Vasilyev; C. Tomei; M. Vignati

2012-02-01T23:59:59.000Z

316

Enhancement of green luminescence of ZnO powders by annealing with carbon black  

SciTech Connect (OSTI)

This paper reports the characterization of nanocrystalline ZnO powders synthesized by a precipitation method and annealed with carbon black. The X-ray diffraction (XRD) and Fourier Transformed Infrared (FT-IR) results revealed that the synthesized ZnO powder has the wurtzite structure with absorbed CO{sub 3}{sup -} species on the surface of the ZnO particles. Singly ionized oxygen vacancy (V{sub O}{sup +}) and CO{sub 3}{sup -} species were also perceived from electron paramagnetic resonance (EPR) analysis. The intensity of the EPR signals of CO{sub 3}{sup -} species increased as the amount of carbon increased whereas that of V{sub O}{sup +} did not vary significantly. A green emission at 528 nm for the powders annealed with carbon was observed and a good correlation between the intensity of green emission and the intensity of EPR signals of CO{sub 3}{sup -} was obtained Experimental results suggest that the formation of the free carriers has significant effect on the intensity of the green emission. The mechanism responsible for the green emission enhancement based on the relevance of the observations is discussed.

Hu Yi [Department of Materials Engineering, Tatung University, Taipei, Taiwan (China)], E-mail: huyi@ttu.edu.tw; Chen, H.-J. [Department of Materials Engineering, Tatung University, Taipei, Taiwan (China)

2008-08-04T23:59:59.000Z

317

A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection  

SciTech Connect (OSTI)

We prepared manganese and europium co-doped zinc sulfide (ZnS:Mn,Eu) phosphors and used them for radiation detection. In addition to the red fluorescence at 583?nm due to the d-d transition of Mn ions, an intense violet emission at 420?nm is newly observed in ZnS:Mn,Eu phosphors. The emission is related to Eu{sup 2+} doping but only appears at certain Eu{sup 2+} concentrations. It is found that the intensity of the 420?nm violet fluorescence is X-ray does-dependent, while the red fluorescence of 583?nm is not. The ratio of fluorescence intensities at 420?nm and 583?nm has been monitored as a function of X-ray doses that exposed upon the ZnS:Mn,Eu phosphors. Empirical formulas are provided to estimate the doses of applied X-ray irradiation. Finally, possible mechanisms of X-ray irradiation induced fluorescence quenching are discussed. The intense 420?nm emission not only provides a violet light for solid state lighting but also offers a very sensitive method for radiation detection.

Ma, Lun; Chen, Wei, E-mail: weichen@uta.edu [Department of Physics and the SAVANT Center, The University of Texas at Arlington, Arlington, Texas 76019-0059 (United States); Jiang, Ke [Center for Biofrontiers Institute, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy., Colorado Springs, Colorado 80918 (United States); Liu, Xiao-tang [Department of Physics and the SAVANT Center, The University of Texas at Arlington, Arlington, Texas 76019-0059 (United States); Department of Applied Chemistry, College of Science, South China Agricultural University, Guangzhou 510642 (China)

2014-03-14T23:59:59.000Z

318

Unexpected magnetization enhancement in hydrogen plasma treated ferromagnetic (Zn,Cu)O film  

SciTech Connect (OSTI)

The effects of H{sup +} incorporation on oxygen vacancies (H{sub O}{sup +}) on the giant ferromagnetic behavior (moment up to 3.26??{sub B}/Cu) in ZnO:Cu polycrystalline films have been closely examined using different microstructural and magnetic characterization tools. Fine thermal stability (up to 450?C) and low resistivity demonstrate a significant correlation between Cu 3d-states and H{sub O}{sup +} donor defects in H plasma treated ZnO:Cu films, analogous to dual-donor (V{sub O} and Zn{sub i}) defects mediated case. These H{sub O}{sup +} donors can delocalize their electrons to the orbits of Cu atoms and contribute to a stronger spin-orbit coupling interaction. Suitable H{sub O}{sup +} defect concentration and matched proportion between Cu{sup 2+} and Cu{sup +} species ensure that orbital momentum shall not be quenched. Hence, unexpected moment enhancement, less than spin-orbit coupling upper limit (3.55??{sub B}/Cu), can be also expected in this scenario. The manipulation from spin-only to spin-orbit coupling mode, using a facile thermally-mediated H plasma exposure way, will allow achieving spin transport based diluted magnetic semiconductor device.

Hu, Liang; Zhu, Liping, E-mail: zlp1@zju.edu.cn, E-mail: hphe@zju.edu.cn; He, Haiping, E-mail: zlp1@zju.edu.cn, E-mail: hphe@zju.edu.cn; Ye, Zhizhen [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China and Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China)

2014-08-18T23:59:59.000Z

319

The new barium zinc mercurides Ba{sub 3}ZnHg{sub 10} and BaZn{sub 0.6}Hg{sub 3.4} - Synthesis, crystal and electronic structure  

SciTech Connect (OSTI)

The title compounds Ba{sub 3}ZnHg{sub 10} and BaZn{sub 0.6}Hg{sub 3.4} were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures, which both represent new structure types, have been determined using single crystal X-ray data. The structure of Ba{sub 3}ZnHg{sub 10} (orthorhombic, oP28, space group Pmmn, a=701.2(3), b=1706.9(8), c=627.3(3)pm, Z=2, R1=0.0657) contains folded 4{sup 4} Hg nets, where the meshes form the bases of flat rectangular pyramids resembling the structure of BaAl{sub 4}. The flat pyramids are connected via Hg-Zn/Hg bonds, leaving large channels at the folds, in which Ba(1) and Hg(2) atoms alternate. Whereas the remaining Hg/Zn atoms form a covalent 3D network of three- to five-bonded atoms with short M-M distances (273-301 pm; CN 9-11), the Hg(2) atoms in the channels adopt a comparatively large coordination number of 12 and increased distances (317-348 pm) to their Zn/Hg neighbours. In the structure of BaZn{sub 0.6}Hg{sub 3.4} (cubic, cI320, space group I4{sup Macron }3d, a=2025.50(7) pm, Z=64, R1=0.0440), with a chemical composition not much different from that of Ba{sub 3}ZnHg{sub 10}, the Zn/Hg atoms of the mixed positions M(1/2) are arranged in an slightly distorted primitive cubic lattice with a 4 Multiplication-Sign 4 Multiplication-Sign 4 subcell relation to the unit cell. The 24 of the originating 64 cubes contain planar cis tetramers Hg(5,6){sub 4} with Hg in a nearly trigonal planar or tetrahedral coordination. In another 24 of the small cubes, two opposing faces are decorated by Hg(3,4){sub 2} dumbbells, two by Ba(2) atoms respectively. The third type of small cubes are centered by Ba(1) atoms only. The complex 3D polyanionic Hg/Zn network thus formed is compared with the Hg partial structure in Rb{sub 3}Hg{sub 20} applying a group-subgroup relation. Despite their different overall structures, the connectivity of the negatively charged Hg atoms, the rather metallic Zn bonding characteristic (as obtained from FP-LAPW band structure calculations) and the coordination number of 16 for all Ba cations relate the two title compounds. - Graphical abstract: Six of the 64 small sub-cubes of three types (A, B, C) forming the unit cell of the Hg-rich mercuride BaZn{sub 0.6}Hg{sub 3.4}. Highlights: Black-Right-Pointing-Pointer Two new Hg-rich Ba mercurides, both synthesized from the elements in pure phase. Black-Right-Pointing-Pointer BaZn{sub 0.6}HgG{sub 3.4} and Ba{sub 3}ZnHg{sub 10} with new complex structure types. Black-Right-Pointing-Pointer Structure relation to other complex cubic intermetallics. Black-Right-Pointing-Pointer Discussion of covalent and metallic bonding aspects, as found by the structure features and band structure calculations.

Schwarz, Michael; Wendorff, Marco [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstr. 21, D-79104 Freiburg (Germany)] [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstr. 21, D-79104 Freiburg (Germany); Roehr, Caroline, E-mail: caroline@ruby.chemie.uni-freiburg.de [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstr. 21, D-79104 Freiburg (Germany)] [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstr. 21, D-79104 Freiburg (Germany)

2012-12-15T23:59:59.000Z

320

Band alignment and interfacial structure of ZnO/Si heterojunction with Al{sub 2}O{sub 3} and HfO{sub 2} as interlayers  

SciTech Connect (OSTI)

Energy band alignment of ZnO/Si heterojunction with thin interlayers Al{sub 2}O{sub 3} and HfO{sub 2} grown by atomic layer deposition has been studied using x-ray photoelectron spectroscopy. The valence band offsets of ZnO/Al{sub 2}O{sub 3} and ZnO/HfO{sub 2} heterojunctions have been determined to be 0.43 and 0.22?eV, respectively. Accordingly, the band alignment ZnO/Si heterojunction is then modified to be 0.34 and 0.50?eV through inserting a thin Al{sub 2}O{sub 3} and HfO{sub 2} layer, respectively. The feasibility to tune the band structure of ZnO/Si heterojunction by selecting a proper interlayer shows great advantage in improving the performance of the ZnO-based optoelectronic devices.

Lu, Hong-Liang, E-mail: honglianglu@fudan.edu.cn; Yang, Ming; Xie, Zhang-Yi; Geng, Yang; Zhang, Yuan; Wang, Peng-Fei; Sun, Qing-Qing; Ding, Shi-Jin; Wei Zhang, David [State Key Laboratory of ASIC and System, Institute of Advanced Nanodevices, School of Microelectronics, Fudan University, Shanghai 200433 (China)

2014-04-21T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
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321

JOURNAL DE PHYSIQUE Collogue CI, supplement au n 4, Tome 38, Avril 1977, page Cl-17 HIGH-FREQUENCY PROPERTIES OF Ni-Zn-Co FERRITES  

E-Print Network [OSTI]

-FREQUENCY PROPERTIES OF Ni-Zn-Co FERRITES IN RELATION TO IRON CONTENT AND MICROSTRUCTURE J. G. M. DE LAU (*) and A-substitution d'ions Co3+ et des ions Co2+ dans des ferrites de Ni-Zn ainsi que la réduction de la taille des+ ions in addition to Co2+ in Ni-Zn ferrites and the reduction of grain size lead to a great improvement

Paris-Sud XI, Université de

322

Relations between structural parameters and physical properties in CdTe and Cd0.96Zn0.04Te alloys  

E-Print Network [OSTI]

481 Relations between structural parameters and physical properties in CdTe and Cd0.96Zn0.04Te cristaux de CdTe et de Cd0,96Zn0,04Te, de densité de dislocations variant entre 5 x 104 et 6 x 105 cm-2. La and photoluminescence experiments were performed on several CdTe and Cd0.96Zn0.04Te crystals with dislocation density

Paris-Sud XI, Université de

323

Synthesis of ZnO nanorodnanosheet composite via facile hydrothermal method and their photocatalytic activities under visible-light irradiation  

SciTech Connect (OSTI)

ZnO composite films consisting of ZnO nanorods and nanosheets were prepared by low-temperature hydrothermal processing at 80 C on seeded glass substrates. The seed layer was coated on glass substrates by solgel dip-coating and pre-heated at 300 C for 10 min prior to hydrothermal growth. The size of the grain formed after pre-heat treatment was ?40 nm. A preferred orientation seed layer at the c-axis was obtained, which promoted vertical growth of the ZnO nanorod arrays and formation of the ZnO nanosheets. X-ray diffraction patterns and high-resolution transmission electron microscope (HR-TEM) images confirmed that the ZnO nanorods and nanosheets consist of single crystalline and polycrystalline structures, respectively. Room temperature photoluminescence spectra of the ZnO nanorodnanosheet composite films exhibited band-edge ultraviolet (UV) and visible emission (blue and green) indicating the formation of ZnO crystals with good crystallinity and are supported by Raman scattering results. The formation of one-dimensional (1D) ZnO nanorod arrays and two-dimensional (2D) ZnO nanosheet films using seeded substrates in a single low-temperature hydrothermal step would be beneficial for realization of device applications that utilize substrates with limited temperature stability. The ZnO nanorods and nanosheets composite structure demonstrated higher photocatalytic activity during degradation of aqueous methylene blue under visible-light irradiation. -- Graphical abstract: Schematic illustration of ZnO nanorodnanosheet composite structure formation by hydrothermal at low-temperature of 80 C against time. Highlights: Novel simultaneous formation of ZnO nanorods and nanosheets composite structure. Facile single hydrothermal step formation at low-temperature. Photoluminescence showed ultraviolet and visible emission. Feasible application on substrates with low temperature stability. Improved photocatalytic activity under visible-light irradiation.

Tan, Wai Kian [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Abdul Razak, Khairunisak; Lockman, Zainovia [School of Materials and Mineral Resources, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Kawamura, Go; Muto, Hiroyuki [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Matsuda, Atsunori, E-mail: matsuda@ee.tut.ac.jp [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan)

2014-03-15T23:59:59.000Z

324

A kinetic study of methanol synthesis in a slurry reactor using a CuO/ZnO/Al2O3 catalyst  

E-Print Network [OSTI]

with the CuO/ZnO, CuO/ZnO/Cr203 and CuO/ZnO/A1203 catalysts, other catalysts are being investigated for practical use. Maj et al. (1985) prepared and characterized ?Th02 snd NH4-Th02 catalysts for methanol production that produced CO conversions of 3'/o.../Thx were reported to demonstrate activity towards methanol synthesis. Recently, Stiles et al. (1991) prepared a catalyst system (~Zn/Co/Cr/(K+Cs) = 4/3/1/0. 028/(15 wt. '/o+4. 0 wt '/o)) with high activity for producing higher alcohols. 1. 2 Objectives...

Al-Adwani, Hamad Abdulwahab

1992-01-01T23:59:59.000Z

325

Exploring the nature of surface barriers on MOF Zn(tbip) by applying IR microscopy in high temporal and spatial resolution  

E-Print Network [OSTI]

(propane) profiles in nanoporous materials (MOF Zn(tbip)) during transient sorption experiments, are found to exhibit notably reduced surface resistances while, with increasing time of storage under

Li, Jing

326

Impact of surface morphology of Si substrate on performance of Si/ZnO heterojunction devices grown by atomic layer deposition technique  

SciTech Connect (OSTI)

In this paper, the authors have investigated the structural, optical, and electrical characteristics of silicon nanowire (SiNW)/zinc oxide (ZnO) coreshell nanostructure heterojunctions and compared their characteristics with Si/ZnO planar heterojunctions to investigate the effect of surface morphology of Si substrate in the characteristics of Si/ZnO heterojunction devices. In this work, ZnO thin film was conformally deposited on both p-type ?100? planar Si substrate and substrate with vertically aligned SiNW arrays by atomic layer deposition (ALD) method. The x-ray diffraction spectra show that the crystalline structures of Si/ZnO heterojunctions are having (101) preferred orientation, whereas vertically oriented SiNW/ZnO coreshell heterojunctions are having (002)-oriented wurtzite crystalline structures. The photoluminescence (PL) spectra of Si/ZnO heterojunctions show a very sharp single peak at 377?nm, corresponding to the bandgap of ZnO material with no other defect peaks in visible region; hence, these devices can have applications only in UV region. On the other hand, SiNW/ZnO heterojunctions are having band-edge peak at 378?nm along with a broad emission band, spreading almost throughout the entire visible region with a peak around 550?nm. Therefore, ALD-grown SiNW/ZnO heterojunctions can emit green and red light simultaneously. Reflectivity measurement of the heterojunctions further confirms the enhancement of visible region peak in the PL spectra of SiNW/ZnO heterojunctions, as the surface of the SiNW/ZnO heterojunctions exhibits extremely low reflectance (<3%) in the visible wavelength region compared to Si/ZnO heterojunctions (>20%). The currentvoltage characteristics of both Si/ZnO and SiNW/ZnO heterojunctions are measured with large area ohmic contacts on top and bottom of the structure to compare the electrical characteristics of the devices. Due to large surface to-volume ratio of SiNW/ZnO coreshell heterojunction devices, the output current rating is about 130 times larger compared to their planar version at 2 V forward bias voltage. This higher output current rating can be exploited for fabricating high-performance nanoelectronic and optoelectronic devices in near future.

Hazra, Purnima; Singh, Satyendra Kumar [Department of Electronics and Communication Engineering, Motilal Neheru National Institute of Technology, Allahabad 211004 (India); Jit, Satyabrata, E-mail: sjit.ece@itbhu.ac.in [Department of Electronics Engineering, Indian Institute of Technology (BHU), Varanasi 221005 (India)

2015-01-01T23:59:59.000Z

327

FINAL REPORT OF RESEARCH ON CuxS/ (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79  

E-Print Network [OSTI]

S/(Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79Research on Photovoltaic Solar Energy Converters CuxSI(Cd~

Chin, B.L.

2013-01-01T23:59:59.000Z

328

Band offsets for mismatched interfaces: The special case of ZnO on CdTe (001)  

SciTech Connect (OSTI)

High-quality planar interfaces between ZnO and CdTe would be useful in optoelectronic applications, but appear difficult to achieve given the rather different crystal structures (CdTe is zinc blende with cubic lattice constant a = 6.482 , ZnO is hexagonal wurtzite with a = 3.253 and c = 5.213 .) However, ZnO has been reported to occur in some epitaxially stabilized films in the zinc blende structure with an fcc primitive lattice constant close to the hexagonal a value. Observing that this value equals half of the CdTe cubic lattice constant to within 1%, we propose that (001)-oriented cubic ZnO films could be grown epitaxially on a CdTe (001) surface in an R45 ?2??2 configuration. Many terminations and alignments (in-plane fractional translations) are possible, and we describe density-functional total-energy electronic-structure calculations on several configurations to identify the most likely form of the interface, and to predict valence-band offsets between CdTe and ZnO in each case. Growth of ZnO on Te-terminated CdTe (001) is predicted to produce small or even negative (CdTe below ZnO) valence band offsets, resulting in a Type I band alignment. Growth on Cd-terminated CdTe is predicted to produce large positive offsets for a type II alignment as needed, for example, in solar cells. We also describe recent experiments that corroborate some of these predictions.

Jaffe, John E.; Kaspar, Tiffany C.; Droubay, Timothy C.; Varga, Tamas

2013-08-02T23:59:59.000Z

329

SnO{sub 2}/ZnO composite structure for the lithium-ion battery electrode  

SciTech Connect (OSTI)

In this article, SnO{sub 2}/ZnO composite structures have been synthesized by two steps hydrothermal method and investigated their lithium storage capacity as compared with pure ZnO. It has been found that these composite structures combining the large specific surface area, stability and catalytic activity of SnO{sub 2} micro-crystals, demonstrate the higher initial discharge capacity of 1540 mA h g{sup -1} with a Coulombic efficiency of 68% at a rate of 120 mA h g{sup -1} between 0.02 and 2 V and found much better than that of any previously reported ZnO based composite anodes. In addition, a significantly enhanced cycling performance, i.e., a reversible capacity of 497 mA h g{sup -1} is retained after 40 cycles. The improved lithium storage capacity and cycle life is attributed to the addition of SnO{sub 2} structure, which act as good electronic conductors and better accommodation of the large volume change during lithiation/delithiation process. - Graphical abstract: SnO{sub 2}/ZnO composite structures demonstrate the improved lithium storage capacity and cycle life as compared with pure ZnO nanostructure. Highlights: Black-Right-Pointing-Pointer Synthesis of SnO{sub 2}/ZnO composite structures by two steps hydrothermal approach. Black-Right-Pointing-Pointer Investigation of lithium storage capacity. Black-Right-Pointing-Pointer Excellent lithium storage capacity and cycle life of SnO{sub 2}/ZnO composite structures.

Ahmad, Mashkoor, E-mail: mashkoorahmad2003@yahoo.com [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China) [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Nanomaterial Research Group, Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Yingying, Shi [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Sun, Hongyu [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Shen, Wanci [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhu, Jing, E-mail: jzhu@mail.tsinghua.edu.cn [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)

2012-12-15T23:59:59.000Z

330

Chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions: A comparison of photoelectron and S L{sub 2,3} x-ray emission spectroscopy  

SciTech Connect (OSTI)

Occurrence and extent of chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions have been investigated by S L{sub 2,3} x-ray emission spectroscopy as well as photoelectron spectroscopy. With the formation of metal-sulfur bonds, spectral features originating from shallow metal d core levels (Zn 3d, In 4d) or valence states (Cu 3d)) may appear in the S L{sub 2,3} emission spectra. Thus the x-ray emission spectroscopy was employed to detect chemical reactions at the heterojunctions, together with conventional photoelectron spectroscopy. Considerable reactions at the Cu/ZnS(001) interface are more clearly indicated in the S L emission spectrum than in the Cu 2p{sub 3sol2} or S 2p core level spectra, whereas relatively confined reactions at the In/ZnS(001) interface can only be probed in the In 3d{sub 5sol2} core level spectra. The partial densities of states calculated for a reference CuInS{sub 2} on the basis of density functional theory agree well with features occurring in its S L{sub 2,3} emission spectrum.

Zhang, L.; Wett, D.; Schulze, D.; Szargan, R.; Nagel, M.; Peisert, H.; Chasse, T. [Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany)

2005-01-03T23:59:59.000Z

331

Hydrogen induced electric conduction in undoped ZnO and Ga-doped ZnO thin films: Creating native donors via reduction, hydrogen donors, and reactivating extrinsic donors  

SciTech Connect (OSTI)

The manner in which hydrogen atoms contribute to the electric conduction of undoped ZnO and Ga-doped ZnO (GZO) films was investigated. Hydrogen atoms were permeated into these films through annealing in an atmospheric H{sub 2} ambient. Because the creation of hydrogen donors competes with the thermal annihilation of native donors at elevated temperatures, improvements to electric conduction from the initial state can be observed when insulating ZnO films are used as samples. While the resistivity of conductive ZnO films increases when annealing them in a vacuum, the degree of increase is mitigated when they are annealed in H{sub 2}. Hydrogenation of ZnO crystals was evidenced by the appearance of OH absorption signals around a wavelength of 2700?nm in the optical transmittance spectra. The lowest resistivity that was achieved by H{sub 2} annealing was limited to 12??10{sup ?2} ? cm, which is one order of magnitude higher than that by native donors (23??10{sup ?3} ? cm). Hence, all native donors are converted to hydrogen donors. In contrast, GZO films that have resistivities yet to be improved become more conductive after annealing in H{sub 2} ambient, which is in the opposite direction of GZO films that become more resistive after vacuum annealing. Hydrogen atoms incorporated into GZO crystals should assist in reactivating Ga{sup 3+} donors.

Akazawa, Housei, E-mail: akazawa.housei@lab.ntt.co.jp [NTT Microsystem Integration Laboratories, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

2014-09-01T23:59:59.000Z

332

Growth of controllable ZnO film by atomic layer deposition technique via inductively coupled plasma treatment  

SciTech Connect (OSTI)

An inductively coupled plasma technique (ICP), namely, remote-plasma treatment was introduced to ionize the water molecules as the precursor for the deposition of ZnO film via the atomic layer deposition processes. Compared with the H{sub 2}O gas as the precursor for the ALD growth, the ionized water molecules can provide a lesser energy to uniformly stabilize oxidization processes, resulting in a better film quality with a higher resistivity owing to less formation of intrinsic defects at a lower growth temperature. The relationship between resistivity and formation mechanisms have been discussed and investigated through analyses of atomic force microscopy, photonluminescence, and absorption spectra, respectively. Findings indicate that the steric hindrance of the ligands plays an important rule for the ALD-ZnO film sample with the ICP treatment while the limited number of bonding sites will be dominant for the ALD-ZnO film without the ICP treatment owing to decreasing of the reactive sites via the ligand-exchange reaction during the dissociation process. Finally, the enhanced aspect-ratio into the anodic aluminum oxide with the better improved uniform coating of ZnO layer after the ICP treatment was demonstrated, providing an important information for a promising application in electronics based on ZnO ALD films.

Huang, Hsin-Wei; Chang, Wen-Chih; Lin, Su-Jien; Chueh, Yu-Lun [Department of Materials Science Engineering and Center For Nanotechnology, Material Science, and Microsystem, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2012-12-15T23:59:59.000Z

333

Mechanism of methanol synthesis on Cu(100) and Zn/Cu(100) surfaces: Comparative dipped adcluster model study  

SciTech Connect (OSTI)

The mechanism of methanol synthesis from CO{sub 2} and H{sub 2} on Cu(100) and Zn/Cu(100) surfaces was studied using the dipped adcluster model (DAM) combined with ab initio Hartree-Fock (HF) and second-order Moeller-Plesset (MP2) calculations. On clean Cu(100) surface, calculations show that five successive hydrogenations are involved in the hydrogenation of adsorbed CO{sub 2} to methanol, and the intermediates are formate, dioxomethylene, formaldehyde, and methoxy. The rate-limiting step is the hydrogenation of formate to formaldehyde, and the Cu-Cu site is responsible for the reaction on Cu(100). The roles of Zn on Zn/Cu(100) catalyst are to modify the rate-limiting step of the reaction: to lower the activation energies of this step and to stabilize the dioxomethylene intermediate at the Cu-Zn site. The present comparative results indicate that the Cu-Zn site is the active site, which cooperates with the Cu-Cu site to catalyze methanol synthesis on a Cu-based catalyst. Electron transfer from surface to adsorbates is the most important factor in affecting the reactivity of these surface catalysts.

Nakatsuji, Hiroshi; Hu, Zhenming

2000-03-05T23:59:59.000Z

334

Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal  

SciTech Connect (OSTI)

Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80-100 {mu}m between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn{sub 2}, Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg-Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: Black-Right-Pointing-Pointer Mg alloy AZ31B and Al alloy 6061 are welded successfully. Black-Right-Pointing-Pointer Zinc wire is employed as a filler metal to form the alloyed welding seam. Black-Right-Pointing-Pointer An alloyed welding seam is benefit for improving of the joint tensile strength.

Liu Fei; Zhang Zhaodong; Liu Liming, E-mail: liulm@dlut.edu.cn

2012-07-15T23:59:59.000Z

335

Zinc vacancy and erbium cluster jointly promote ferromagnetism in erbium-doped ZnO thin film  

SciTech Connect (OSTI)

Zn{sub 1-x}Er{sub x}O (0.005 ? x ? 0.04) thin films have been prepared by inductively coupled plasma enhanced physical vapor deposition method. Ferromagnetism, crystal structure, microstructure and photoluminescence properties of the films were characterized. It is found that the chemical valence state of Er is trivalent, and the Er{sup 3+} cations play an important role in ferromagnetism. Both saturated magnetization (M{sub s}) and zinc vacancy (V{sub Zn}) are decreased with the increase of x from 0.005 to 0.03. However, further increasing x to 0.04, the M{sub s} is quenched due to the generation of Er clusters. It reveals that the intensity of M{sub s} is not only associated with the V{sub Zn} concentration, but also related to the Er clusters. The V{sub Zn} concentration and the Er clusters can jointly boost the ferromagnetism in the Zn{sub 1-x}Er{sub x}O thin films.

Chen, Hong-Ming; Zhou, Ren-Wei; Li, Fei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China) [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Xue-Chao, E-mail: xcliu@mail.sic.ac.cn; Zhuo, Shi-Yi; Shi, Er-Wei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China)] [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China); Xiong, Ze [Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (China)] [Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

2014-04-15T23:59:59.000Z

336

Thermal conductivity of Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} solid solutions  

SciTech Connect (OSTI)

{beta}-Zn{sub 4}Sb{sub 3} was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy {beta}-Zn{sub 4}Sb{sub 3} with isostructural compounds because of the expected decrease in lattice thermal conductivity. The authors have grown Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} crystals with 0.2 {le} x < 1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} alloys are significantly lower than those measured for {beta}-Zn{sub 4}Sb{sub 3} and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications.

Caillat, T.; Borshchevsky, A.; Fleurial, J.P.

1997-07-01T23:59:59.000Z

337

Visible light plasmonic heating of Au-ZnO for the catalytic reduction of CO{sub 2}  

SciTech Connect (OSTI)

Plasmonic excitation of Au nanoparticles attached to the surface of ZnO catalysts using low power 532 nm laser illumination leads to significant heating of the catalyst and the conversion of CO{sub 2} and H{sub 2} reactants to CH{sub 4} and CO products. Temperature-calibrated Raman spectra of ZnO phonons show that intensity-dependent plasmonic excitation can controllably heat AuZnO from 30 to #1;~600 {degrees}#3;C and simultaneously tune the CH{sub 4} : CO product ratio. The laser induced heating and resulting CH{sub 4} : CO product distribution agrees well with predictions from thermodynamic models and temperatureprogrammed reaction experiments indicating that the reaction is a thermally driven process resulting from the plasmonic heating of the AuZnO. The apparent quantum yield for CO{sub 2} conversion under continuous wave (cw) 532 nm laser illumination is 0.030%. The AuZnO catalysts are robust and remain active after repeated laser exposure and cycling. The light intensity required to initiate CO{sub 2} reduction is low (#1;~2.5 x#4; 10{sup 5} W m{sup #5;-2}) and achievable with solar concentrators. Our results illustrate the viability of plasmonic heating approaches for CO{sub 2} utilization and other practical thermal catalytic applications.

Wang, Congjun; Ranasingha, Oshadha; Natesakhawat, Sittichai; Ohodnicki, Paul R.; Ohodnicki, Andio, Mark; Lewis, James; P Matranga, Christopher

2013-05-01T23:59:59.000Z

338

Photoluminescence properties and energy levels of RE (RE?=?Pr, Sm, Er, Tm) in layered-CaZnOS oxysulfide  

SciTech Connect (OSTI)

RE{sup 3+} (RE?=?Pr, Sm, Er, Tm)-activated CaZnOS samples were prepared by a solid-state reaction method at high temperature, and their photoluminescence properties were investigated. Doping with RE{sup 3+} (RE?=?Pr, Sm, Er, Tm) into layered-CaZnOS resulted in typical RE{sup 3+} (RE?=?Pr, Sm, Er, Tm) f-f line absorptions and emissions, as well as the charge transfer band of Sm{sup 3+} at about 3.3?eV. The energy level scheme containing the position of the 4f and 5d levels of all divalent and trivalent lanthanide ions with respect to the valence and conduction bands of CaZnOS has been constructed based on the new data presented in this work, together with the data from literature on Ce{sup 3+} and Eu{sup 2+} doping in CaZnOS. The detailed energy level scheme provides a platform for interpreting the optical spectra and could be used to comment on the valence stability of the lanthanide ions in CaZnOS.

Zhang, Zhi-Jun, E-mail: zhangzj@mail.sic.ac.cn [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai 200050 (China); Feng, Ang; Chen, Xiang-Yang [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Zhao, Jing-Tai, E-mail: jtzhao@mail.sic.ac.cn [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai 200050 (China); School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

2013-12-07T23:59:59.000Z

339

MoS{sub 2}@ZnO nano-heterojunctions with enhanced photocatalysis and field emission properties  

SciTech Connect (OSTI)

The molybdenum disulfide (MoS{sub 2})@ZnO nano-heterojunctions were successfully fabricated through a facile three-step synthetic process: prefabrication of the ZnO nanoparticles, the synthesis of MoS{sub 2} nanoflowers, and the fabrication of MoS{sub 2}@ZnO heterojunctions, in which ZnO nanoparticles were uniformly self-assembled on the MoS{sub 2} nanoflowers by utilizing polyethyleneimine as a binding agent. The photocatalytic activities of the composite samples were evaluated by monitoring the photodegradation of methylene blue (MB). Compared with pure MoS{sub 2} nanoflowers, the composites show higher adsorption capability in dark and better photocatalytic efficiency due to the increased specific surface area and improved electron-hole pair separation. After irradiation for 100?min, the remaining MB in solution is about 7.3%. Moreover, the MoS{sub 2}@ZnO heterojunctions possess enhanced field emission properties with lower turn-on field of 3.08?V ?m{sup ?1}and lower threshold field of 6.9?V ?m{sup ?1} relative to pure MoS{sub 2} with turn-on field of 3.65?V ?m{sup ?1} and threshold field of 9.03?V ?m{sup ?1}.

Tan, Ying-Hua; Yu, Ke, E-mail: yk5188@263.net; Li, Jin-Zhu; Fu, Hao; Zhu, Zi-Qiang [Key Laboratory of Polar Materials and Devices (Ministry of Education of China), Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China)

2014-08-14T23:59:59.000Z

340

Comparative Study of the Defect Point Physics and Luminescence of the Kesterites Cu2ZnSnS4 and Cu2ZnSnSe4 and Chalcopyrite Cu(In,Ga)Se2: Preprint  

SciTech Connect (OSTI)

In this contribution, we present a comparative study of the luminescence of the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) and their related chalcopyrite Cu(In,Ga)Se2 (CIGSe). Luminescence spectroscopy suggests that the electronic properties of Zn-rich, Cu-poor kesterites (both CZTS and CZTSe) and Cu-poor CIGSe are dictated by fluctuations of the electrostatic and chemical potentials. The large redshift in the luminescence of grain boundaries in CIGSe, associated with the formation of a neutral barrier is clearly observed in CZTSe, and, to some extent, in CZTS. Kesterites can therefore replicate the fundamental electronic properties of CIGSe.

Romero, M. J.; Repins, I.; Teeter, G.; Contreras, M.; Al-Jassim, M.; Noufi, R.

2012-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

PROPRITS MAGNTIQUES DU FERRITE DE ZINC (Fe2 O3.Zn O)  

E-Print Network [OSTI]

PROPRI?T?S MAGN?TIQUES DU FERRITE DE ZINC (Fe2 O3.Zn O) EN RELATION AVEC SA STRUCTURE Par CH. GUILLAUD et M. SAGE. Sommaire. - On a préparé des ferrites de zinc et étudié leurs propriétés magnétiques distribution des ions dans le réseau. Nous avons préparé ce ferrite par les méthodes classiques du mélange d

Paris-Sud XI, Université de

342

Core-shell ITO/ZnO/CdS/CdTe nanowire solar cells  

SciTech Connect (OSTI)

Radial p-n junction nanowire (NW) solar cells with high densities of CdTe NWs coated with indium tin oxide (ITO)/ZnO/CdS triple shells were grown with excellent heterointerfaces. The optical reflectance of the devices was lower than for equivalent planar films by a factor of 100. The best efficiency for the NW solar cells was ??=?2.49%, with current transport being dominated by recombination, and the conversion efficiencies being limited by a back contact barrier (?{sub B}?=?0.52?eV) and low shunt resistances (R{sub SH}?

Williams, B. L.; Phillips, L.; Major, J. D.; Durose, K. [Stephenson Institute for Renewable Energy, University of Liverpool, Chadwick Building, Peach St., Liverpool L69 7ZF (United Kingdom); Taylor, A. A.; Mendis, B. G.; Bowen, L. [G. J. Russell Microscopy Facility, University of Durham, South Road, Durham DH1 3LE (United Kingdom)

2014-02-03T23:59:59.000Z

343

Injection photodiodes based on low-resistivity ZnS single crystals  

SciTech Connect (OSTI)

Results of an experimental study of Ni-n-n{sup +}-In photodiode structures fabricated from a low-resistivity ZnS:Al crystal (n{sup +}-region) are reported. The high-resistivity compensated n-type layer is produced by thermal diffusion of silver. The photodiodes exhibit an injection amplification of the photocurrent under a forward bias of 1-10 V. The dependence of the currents through the diodes on the thickness of the n-type layer in the dark and under UV irradiation is determined. The photosensitivity is at a maximum in the fundamental absorption range in a narrow spectral band.

Losev, V. V., E-mail: morozova-tamara@mail.ru [Moscow State Institute (Technical University) of Electronic Engineering (Russian Federation)

2009-12-15T23:59:59.000Z

344

Plasma spectroscopic study of an electrodeless HID lamp containing Tl and Zn  

SciTech Connect (OSTI)

Recently the electrodeless HID lamps excited by microwaves have been studied intensively. Tl is well known as a material having strong green emission lines. In this study, Tl spectra excited by microwaves were reported in the cases of Tl only and Tl + Zn. Using the Elenbaas`s method of high pressure Hg lamp, the cause of Tl continuous spectrum was examined. From the ratio of radiative intensities of two lines, an average arc temperature in the bulb was estimated. Then excitation level of the continuous emission spectrum near the 600nm wavelength was calculated from the dependence of the radiative intensities on these arc temperatures.

Takeda, Mamoru; Horii, Shigeru; Hochi, Akira [Matsushita Electric Industrial Co., Ltd., Kyoto (Japan). Lighting Research Lab.

1996-12-31T23:59:59.000Z

345

Characterization of ZnSe scintillating bolometers for Double Beta Decay  

E-Print Network [OSTI]

ZnSe scintillating bolometers are good candidates for future Double Beta Decay searches, because of the 82Se high Q-value and thanks to the possibility of alpha background rejection on the basis of the scintillation signal. In this paper we report the characteristics and the anomalies observed in an extensive study of these devices. Among them, an unexpected high emission from alpha particles, accompanied with an unusual pattern of the light vs. heat scatter plot. The perspectives for the application of this kind of detectors to search for the Neutrinoless Double Beta Decay of 82Se are presented.

C. Arnaboldi; S. Capelli; O. Cremonesi; L. Gironi; M. Pavan; G. Pessina; S. Pirro

2010-06-30T23:59:59.000Z

346

High Resolution Optically Addressed Spatial Light Modulator based on ZnO Nanoparticles  

E-Print Network [OSTI]

temperatures. (d) Temporal current response with and without illumination. Samples are illuminated by 10 mW cm -2 of 365 nm light emitting diode with 6 V dc being applied throughout. Electrical characterization For conductivity measurement, two rectangular... of the corresponding dark/photo currents of the ITO-ZnO-ITO structures are carried out using Agilent 4156 together with a 365 nm light emitting diode light source of 2 mW cm-2. The conductivity, ? , of the sample is calculated as, dI LtV? ? (2) where, d...

Shrestha, Pawan Kumar; Chun, Young Tea; Chu, Daping

2015-01-01T23:59:59.000Z

347

Bendable ZnO thin film surface acoustic wave devices on polyethylene terephthalate substrate  

SciTech Connect (OSTI)

Bendable surface acoustic wave (SAW) devices were fabricated using high quality c-axis orientation ZnO films deposited on flexible polyethylene terephthalate substrates at 120?C. Dual resonance modes, namely, the zero order pseudo asymmetric (A{sub 0}) and symmetric (S{sub 0}) Lamb wave modes, have been obtained from the SAW devices. The SAW devices perform well even after repeated flexion up to 2500??? for 100 times, demonstrating its suitability for flexible electronics application. The SAW devices are also highly sensitive to compressive and tensile strains, exhibiting excellent anti-strain deterioration property, thus, they are particularly suitable for sensing large strains.

He, Xingli; Guo, Hongwei; Chen, Jinkai; Wang, Wenbo; Xuan, Weipeng; Xu, Yang, E-mail: yangxu-isee@zju.edu.cn, E-mail: jl2@bolton.ac.uk [Department of Info. Sci. and Electron. Eng., Zhejiang University and Cyrus Tang Center for Sensor Mater. and Appl., 38 Zheda Road, Hangzhou 310027 (China); Luo, Jikui, E-mail: yangxu-isee@zju.edu.cn, E-mail: jl2@bolton.ac.uk [Department of Info. Sci. and Electron. Eng., Zhejiang University and Cyrus Tang Center for Sensor Mater. and Appl., 38 Zheda Road, Hangzhou 310027 (China); Institute of Renew. Energ. and Environ. Tech., University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom)

2014-05-26T23:59:59.000Z

348

Tuning of defects in ZnO nanorod arrays used in bulk heterojunction solar cells  

E-Print Network [OSTI]

by radio frequency magnetron sputtering. J Mater Res 2005, 20:15741579. 55. Cui J: Zinc oxide nanowires. Mater Charact 2012, 64:4352. 56. Fan Z, Wang D, Chang P-C, Tseng W-Y, Lu JG: ZnO nanowire field-effect transistor and oxygen sensing property. Appl... to 130 nm in diameter and ca. 800 nm in length. Figure 1d,e shows cross-sectional images of the solar cell devices produced herein, which will be discussed later. Results and discussion Firstly, we present the PL data on our samples together with IR...

Iza, Diana C; Muoz-Rojas, David; Jia, Quanxi; Swartzentruber, Brian; MacManus-Driscoll, Judith L

2012-11-27T23:59:59.000Z

349

Low-temperature recrystallization of Ge nanolayers on ZnSe  

SciTech Connect (OSTI)

The in situ X-ray photoelectron spectroscopy observation of low-temperature recrystallization of an amorphous Ge layer deposited on a ZnSe film at room temperature is reported. It is shown that the experimentally measured shifts of the Ge 3d core level are consistent with the changes observed in the crystal structure of the layer by the high-energy electron diffraction technique in the reflection mode of measurements. The shifts can be attributed to successive nanometer-scaled structural changes in the Ge layer with increasing temperature.

Suprun, S. P., E-mail: suprun@thermo.isp.nsc.ru; Fedosenko, E. V. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Division (Russian Federation)

2007-05-15T23:59:59.000Z

350

Synthesis and Luminescence of ZnMgS:Mn2+ Nanoparticles. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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351

Electrodeposition of ZnO Nanorods in the Presence of Metal Ions. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles as Selective Sorbents . |of ZnO Nanorods in the Presence

352

ZnS Thin Films Deposited by a Spin Successive Ionic Layer Adsorption and  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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353

Stabilization of ZnMnO3 Phase from Sol-gel Synthesized Nitrate Precursors .  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSiteNeutron Scattering4 By I.| EMSL ZnMnO3 Phase from Sol-gel

354

Suppression of conductivity in Mn-Doped ZnO Thin Films. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline GalliumSuppression of conductivity in Mn-Doped ZnO Thin Films.

355

One-photon band gap engineering of borate glass doped with ZnO for photonics applications  

SciTech Connect (OSTI)

Lithium tungsten borate glass of the composition (0.56-x)B{sub 2}O{sub 3}-0.4Li{sub 2}O-xZnO-0.04WO{sub 3} (0 {<=}x{<=} 0.1 mol. %) is prepared for photonics applications. The glass is doped with ZnO to tune the glass absorption characteristics in a wide spectrum range (200-2500 nm). Chemical bond approach, including chemical structure, electronegativity, bond ionicity, nearest-neighbor coordination, and other chemical bonding aspect, is used to analyze and to explain the obtained glass properties such as: transmittance, absorption, electronic structure parameters (bandgap, Fermi level, and Urbach exciton-phonon coupling), Wannier free excitons excitation (applying Elliott's model), and two-photon absorption coefficient as a result of replacement of B{sub 2}O{sub 3} by ZnO.

Abdel-Baki, Manal [Glass Department, National Research Centre, Dokki 12311 Giza (Egypt); Abdel-Wahab, Fathy A.; El-Diasty, Fouad [Physics Department, Faculty of Science, Ain Shams University, Abbasia, 11566 Cairo (Egypt)

2012-04-01T23:59:59.000Z

356

Performance of ZnMoO4 crystal as cryogenic scintillating bolometer to search for double beta decay of molybdenum  

E-Print Network [OSTI]

Zinc molybdate (ZnMoO4) single crystals were grown for the first time by the Czochralski method and their luminescence was measured under X ray excitation in the temperature range 85-400 K. Properties of ZnMoO4 crystal as cryogenic low temperature scintillator were checked for the first time. Radioactive contamination of the ZnMoO4 crystal was estimated as <0.3 mBq/kg (228-Th) and 8 mBq/kg (226-Ra). Thanks to the simultaneous measurement of the scintillation light and the phonon signal, the alpha particles can be discriminated from the gamma/beta interactions, making this compound extremely promising for the search of neutrinoless Double Beta Decay of 100-Mo. We also report on the ability to discriminate the alpha-induced background without the light measurement, thanks to a different shape of the thermal signal that characterizes gamma/beta and alpha particle interactions.

L. Gironi; C. Arnaboldi; J. W. Beeman; O. Cremonesi; F. A. Danevich; V. Ya. Degoda; L. I. Ivleva; L. L. Nagornaya; M. Pavan; G. Pessina; S. Pirro; V. I. Tretyak; I. A. Tupitsyna

2010-10-01T23:59:59.000Z

357

Reduction of surface leakage current by surface passivation of CdZn Te and other materials using hyperthermal oxygen atoms  

DOE Patents [OSTI]

Reduction of surface leakage current by surface passivation of Cd.sub.1-x Zn.sub.x Te and other materials using hyperthermal oxygen atoms. Surface effects are important in the performance of CdZnTe room-temperature radiation detectors used as spectrometers since the dark current is often dominated by surface leakage. A process using high-kinetic-energy, neutral oxygen atoms (.about.3 eV) to treat the surface of CdZnTe detectors at or near ambient temperatures is described. Improvements in detector performance include significantly reduced leakage current which results in lower detector noise and greater energy resolution for radiation measurements of gamma- and X-rays, thereby increasing the accuracy and sensitivity of measurements of radionuclides having complex gamma-ray spectra, including special nuclear materials.

Hoffbauer, Mark A. (Los Alamos, NM); Prettyman, Thomas H. (Los Alamos, NM)

2001-01-01T23:59:59.000Z

358

Atom-probe tomographic study of interfaces of Cu{sub 2}ZnSnS{sub 4} photovoltaic cells  

SciTech Connect (OSTI)

The heterophase interfaces between the CdS buffer layer and the Cu{sub 2}ZnSnS{sub 4} (CZTS) absorption layers are one of the main factors affecting photovoltaic performance of CZTS cells. We have studied the compositional distributions at heterophase interfaces in CZTS cells using three-dimensional atom-probe tomography. The results demonstrate: (a) diffusion of Cd into the CZTS layer; (b) segregation of Zn at the CdS/CZTS interface; and (c) a change of oxygen and hydrogen concentrations in the CdS layer depending on the heat treatment. Annealing at 573?K after deposition of CdS improves the photovoltaic properties of CZTS cells probably because of the formation of a heterophase epitaxial junction at the CdS/CZTS interface. Conversely, segregation of Zn at the CdS/CZTS interface after annealing at a higher temperature deteriorates the photovoltaic properties.

Tajima, S., E-mail: e0954@mosk.tytlabs.co.jp; Asahi, R.; Itoh, T.; Hasegawa, M.; Ohishi, K. [Toyota Central R and D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Isheim, D.; Seidman, D. N. [Northwestern University, Evanston, Illinois 60208-3108 (United States)

2014-09-01T23:59:59.000Z

359

Interaction between O{sub 2} and ZnO films probed by time-dependent second-harmonic generation  

SciTech Connect (OSTI)

The interaction between O{sub 2} and ZnO thin films prepared by atomic layer deposition has been investigated by time-dependent second-harmonic generation, by probing the electric field induced by adsorbed oxygen molecules on the surface. The second-harmonic generated signal decays upon laser exposure due to two-photon assisted desorption of O{sub 2}. Blocking and unblocking the laser beam for different time intervals reveals the adsorption rate of O{sub 2} onto ZnO. The results demonstrate that electric field induced second-harmonic generation provides a versatile non-contact probe of the adsorption kinetics of molecules on ZnO thin films.

Andersen, S. V., E-mail: sva@nano.aau.dk [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg st (Denmark); Vandalon, V.; Bosch, R. H. E. C.; Loo, B. W. H. van de; Kessels, W. M. M., E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg st (Denmark)

2014-02-03T23:59:59.000Z

360

Optical channel waveguides written by high repetition rate femtosecond laser irradiation in Li-Zn fluoroborate glass  

E-Print Network [OSTI]

Low loss, optical channel waveguides have been successfully produced by high repetition rate, femtosecond laser inscription in a Li-Zn fluoroborate glass (64.9B2O3 + 25Li2O + 10ZnF2 + 0.1Er2O3). High quality waveguides were produced at 500 kHz, 1 MHz and 2 MHz laser repetition rates, showing a refractive index contrast in the range of 3-6 x 10-3 depending on various fluences. Dependence of experimental parameters such as average laser power, pulse repetition rate and writing speed on the properties of fabricated waveguides has been discussed. The comparison of optical and compositional characterization techniques evidences an enrichment of B and Zn in the guiding region, while F migrates to the heat diffused region of the written structure.

Thomas, Sunil; Solis, Javier; Biju, P R; Unnikrishnan, N V

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

JOURNAL DE PHYSIQUE Colloque Cl, supplkment au no 4, Tome 38, Auril 1977, page Cl-303 MULTILAYER SINTERING OF MnZn FERRITES  

E-Print Network [OSTI]

SINTERING OF MnZn FERRITES IN CONTROLLED ATMOSPHERE M. I. ALAM, N. R. NAlR and T. V. RAMAMURTI Central dans la litterature que I'empilement depots de ferrites les uns sur les autres durant le traitement production des couches multiples d'echantillons de ferrite de Mn-Zn. On a utilise jusqu'a 10 couches d

Boyer, Edmond

362

A Highly Efficient Solar Cell Made from a Dye-Modified ZnO-Covered TiO2 Nanoporous Electrode  

E-Print Network [OSTI]

-circuit photovoltage. Introduction Overall power conversion efficiency1,2 reaching 10% for dye sensitized solar cellA Highly Efficient Solar Cell Made from a Dye-Modified ZnO-Covered TiO2 Nanoporous Electrode Zhong A photoelectrochemical solar cell based on porous ZnO-covered TiO2 film has been fabricated with ruthenium bipyridyl

Huang, Yanyi

363

Effect of Synthesis Condition and Annealing on the Sensitivity and Stability of Gas Sensors Made of Zn-Doped y-Fe2O3 Particles  

E-Print Network [OSTI]

In this study, the effect of synthesis conditions and annealing process on the sensitivity and stability of gas sensors made of flame-synthesized Zn-doped ?-Fe2O3 particles was investigated. Zn-doped ?-Fe2O3 particles were synthesized by flame...

Kim, Taeyang

2010-10-12T23:59:59.000Z

364

Interpretation of the Phonon Frequency Shifts in ZnO Quantum Dots Khan A. Alim, Vladimir A. Fonoberov, and Alexander A. Balandin  

E-Print Network [OSTI]

made of zinc oxide (ZnO), a wide-bandgap semiconductor, have recently attracted attention due Zinc oxide (ZnO) presents interesting material system because of its wide band gap of 3.37 eV and some ultraviolet (UV) protection films, gas sensors, and varistors. Raman spectroscopy presents a powerful tool

Fonoberov, Vladimir

365

CdS and CdS/CdSe sensitized ZnO nanorod array solar cells prepared by a solution ions exchange process  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: CdS and CdS/CdSe quantum dots are assembled on ZnO nanorods by ion exchange process. The CdS/CdSe sensitization of ZnO effectively extends the absorption spectrum. The performance of ZnO/CdS/CdSe cell is improved by extending absorption spectrum. - Abstract: In this paper, cadmium sulfide (CdS) and cadmium sulfide/cadmium selenide (CdS/CdSe) quantum dots (QDs) are assembled onto ZnO nanorod arrays by a solution ion exchange process for QD-sensitized solar cell application. The morphology, composition and absorption properties of different photoanodes were characterized with scanning electron microscope, transmission electron microscope, energy-dispersive X-ray spectrum and Raman spectrum in detail. It is shown that conformal and uniform CdS and CdS/CdSe shells can grow on ZnO nanorod cores. Quantum dot sensitized solar cells based on ZnO/CdS and ZnO/CdS/CdSe nanocable arrays were assembled with gold counter electrode and polysulfide electrolyte solution. The CdS/CdSe sensitization of ZnO can effectively extend the absorption spectrum up to 650 nm, which has a remarkable impact on the performance of a photovoltaic device by extending the absorption spectrum. Preliminary results show one fourth improvement in solar cell efficiency.

Chen, Ling; Gong, Haibo; Zheng, Xiaopeng; Zhu, Min; Zhang, Jun [Key Laboratory of Inorganic Functional Materials in Universities of Shandong, School of Materials Science and Engineering, University of Jinan, Jinan 250022, Shandong (China); Yang, Shikuan [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802-6812 (United States); Cao, Bingqiang, E-mail: mse_caobq@ujn.edu.cn [Key Laboratory of Inorganic Functional Materials in Universities of Shandong, School of Materials Science and Engineering, University of Jinan, Jinan 250022, Shandong (China)

2013-10-15T23:59:59.000Z

366

The effect of Au and Ni doping on the heavy fermion state of the Kondo lattice antiferromagnet CePtZn  

SciTech Connect (OSTI)

We have probed the effect of doping CePtZn with Au and Ni and also investigated in detail the magnetic behavior of the iso-structural CeAuZn. A magnetic ground state is observed in both CePt{sub 0.9}Au{sub 0.1}Zn and CePt{sub 0.9}Ni{sub 0.1}Zn with T{sub N}?=?2.1 and 1.1?K and the coefficient of the linear term of electronic heat capacity ??=?0.34 and 0.9?J/mol K{sup 2}, respectively. The corresponding values for CePtZn are 1.7?K and 0.6?J/mol K{sup 2}. The altered values of T{sub N} and ? show that the electronic correlations in CePtZn are affected by doping with Au and Ni. CeAuZn orders magnetically near 1.7?K and its electrical resistivity shows a normal metallic behavior. Together with a ? of 0.022?J/mol K{sup 2} the data indicate a weak 4f-conduction electron hybridization in CeAuZn characteristic of normal trivalent cerium based systems.

Dhar, S. K., E-mail: sudesh@tifr.res.in [DCMPMS, T.I.F.R., Homi Bhabha Road, Colaba, Mumbai 400005 (India); Aoki, Y.; Suemitsu, B.; Miyazaki, R. [Department of Physics, Tokyo Metropolitan University, Minami-Ohsawa 1-1, Hachioji-Shi, Tokyo (Japan); Provino, A.; Manfrinetti, P. [Departimento Physica Chemicale, Universita di Genova, Via Dodecaneso, 16146 Genova (Italy)

2014-05-07T23:59:59.000Z

367

Intrinsic current-voltage properties of nanowires with four-probe scanning tunneling microscopy: A conductance transition of ZnO nanowire  

E-Print Network [OSTI]

strain. The ZnO-nanowire samples used in our experiments were synthesized via reduction and oxidation of ZnS powder13 and dispersed on a silicon wafer coated with a 500-nm-thick silicon dioxide layer as insulator. The STM tips were made from a tungsten or gold wire using the stan- dard preparation proce

Liu, Feng

368

The 3-stage evolution of the Angouran Zn "oxide"-sulfide deposit, Iran Fakultt Chemie, Technische Universitt Mnchen, Germany albert.gilg@geo.tum.de  

E-Print Network [OSTI]

The 3-stage evolution of the Angouran Zn "oxide"-sulfide deposit, Iran H.A. Gilg Fakultät Chemie@unina.it F. Moore Geological Department, University Shiraz, Iran moor@geology.susc.ac.ir Keywords: Angouran, Iran, sulfide, MVT, smithsonite, hypogene, supergene ABSTRACT: The giant Angouran Zn-Pb deposit (Zanjan

Boni, Maria

369

Carbonaceous spheresan unusual template for solid metal oxide mesoscale spheres: Application to ZnO spheres  

SciTech Connect (OSTI)

A green template route for the synthesis of mesoscale solid ZnO spheres was ascertained. The protocol involves a double coating of the carbonaceous spheres with successive layers of zinc-containing species by alternating a non-ultrasound and ultrasound-assisted deposition, followed by calcination treatments. The composites were characterized by FTIR spectroscopy, thermal analysis, scanning electron microscopy while the obtained ZnO spheres by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy, N{sub 2} adsorptiondesorption isotherms and photoluminescence investigations. A growth mechanism of the solid spheres is advanced based on these results. While the spheres' diameters and the mean size values of ZnO are independent on deposition order, the surface area and the external porosity are fairly dependent. The photoluminescence measurements showed interesting emission features, with emission bands in the violet to orange region. The spheres present high photocatalytical activity towards the degradation of phenol under UV irradiation, the main reaction being its mineralization. - Graphical abstract: A novel and eco-friendly methodology for the synthesis of mesoscale solid ZnO spheres was developed. The protocol involves a double coating of the starch-derived carbonaceous spheres with successive layers of zinc-containing species by alternating a non-ultrasound and ultrasound-assisted deposition, followed by calcination treatments. - Highlights: ZnO solid spheres are obtained via a template route using carbonaceous spheres. Two-step coatings of interchangeable order are used as deposition procedure. The coating procedure influences the porosity and surface area. ZnO spheres exhibited interesting visible photoluminescence properties. Solid spheres showed photocatalytical activity in degradation of phenol.

Patrinoiu, Greta; Caldern-Moreno, Jose Maria; Culita, Daniela C. [Illie Murgulescu Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest (Romania); Birjega, Ruxandra [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box Mg27, Magurele, Bucharest (Romania); Ene, Ramona [Ilie Murgulescu Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest (Romania); Carp, Oana, E-mail: ocarp@icf.ro [Ilie Murgulescu Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest (Romania)

2013-06-15T23:59:59.000Z

370

Structural characterization and novel optical properties of defect chalcopyrite ZnGa{sub 2}Te{sub 4} thin films  

SciTech Connect (OSTI)

Highlights: {yields} Preparation and characterization of ZnGa{sub 2}Te{sub 4} in powder and thin film forms. {yields} Structure properties such as XRD and EDX. {yields} Optical constant of the as-deposited ZnGa{sub 2}Te{sub 4} for the first time. {yields} Extraction of the optical parameters of the studied films. -- Abstract: Stoichiometric thin film samples of the ternary ZnGa{sub 2}Te{sub 4} defect chalcopyrite compound were prepared and characterized by X-ray diffraction technique. The elemental chemical composition of the prepared bulk material as well as of the as-deposited film was determined by energy-dispersive X-ray spectrometry. ZnGa{sub 2}Te{sub 4} thin films were deposited, by conventional thermal evaporation technique onto highly cleaned glass substrates. The X-ray and electron diffraction studies revealed that the as-deposited and the annealed ZnGa{sub 2}Te{sub 4} films at annealing temperature t{sub a} {<=} 548 K are amorphous, while those annealed at t{sub a} {>=} 573 K (for 1 h), are polycrystalline. The optical properties of the as-deposited films have been investigated for the first time at normal incidence in the spectral range from 500 to 2500 nm. The refractive index dispersion in the transmission and low absorption region is adequately described by the Wemple-DiDomenico single oscillator model, whereby, the values of the oscillator parameters have been calculated. The analysis of the optical absorption coefficient revealed an in-direct optical transition with energy of 1.33 eV for the as-deposited sample. This work suggested that ZnGa{sub 2}Te{sub 4} is a good candidate in solar cell devices as an absorbing layer.

Fouad, S.S., E-mail: icgegypt@link.net [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Sakr, G.B., E-mail: gamalsaker@yahoo.com [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Yahia, I.S., E-mail: dr_isyahia@yahoo.com [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Basset, D.M. Abdel, E-mail: dalia.physics@gmail.com [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt)] [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt)

2011-11-15T23:59:59.000Z

371

Growth of highly doped p-type ZnTe films by pulsed laser ablation in molecular nitrogen  

SciTech Connect (OSTI)

Highly p-doped ZnTe films have been grown on semi-insulating GaAs (001) substrates by pulsed-laser ablation (PLA) of a stoichiometric ZnTe target in a high-purity N{sub 2} ambient without the use of any assisting (DC or AC) plasma source. Free hole concentrations in the mid-10{sup 19} cm{sup {minus}3} to > 10{sup 20} cm{sup {minus}3} range were obtained for a range of nitrogen pressures The maximum hole concentration equals the highest hole doping reported to date for any wide band gap II-VI compound. The highest hole mobilities were attained for nitrogen pressures of 50--100 mTorr ({approximately}6.5-13 Pa). Unlike recent experiments in which atomic nitrogen beams, extracted from RF and DC plasma sources, were used to produce p-type doping during molecular beam epitaxy deposition, spectroscopic measurements carried out during PLA of ZnTe in N{sub 2} do not reveal the presence of atomic nitrogen. This suggests that the high hole concentrations in laser ablated ZnTe are produced by a new and different mechanism, possibly energetic beam-induced reactions with excited molecular nitrogen adsorbed on the growing film surface, or transient formation of Zn-N complexes in the energetic ablation plume. This appears to be the first time that any wide band gap (Eg > 2 eV) II-VI compound (or other) semiconductor has been impurity-doped from the gas phase by laser ablation. In combination with the recent discovery that epitaxial ZnSe{sub l-x}S{sub x} films and heterostructures with continuously variable composition can be grown by ablation from a single target of fixed composition, these results appear to open the way to explore PLA growth and doping of compound semiconductors as a possible alternative to molecular beam epitaxy.

Lowndes, D.H.; Rouleau, C.M.; Budai, J.D.; Poker, D.B.; Geohegan, D.B.; Zhu, Shen [Oak Ridge National Lab., TN (United States); McCamy, J.W. [Harvard Univ., Cambridge, MA (United States). Div. of Applied Science; Puretzky, A. [Institute of Spectroscopy, Troitsk (Russian Federation)

1995-04-01T23:59:59.000Z

372

Enhancement of surface phonon modes in the Raman spectrum of ZnSe nanoparticles on adsorption of 4-mercaptopyridine  

SciTech Connect (OSTI)

By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm{sup ?1}) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations.

Islam, Syed K.; Lombardi, John R. [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)] [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)

2014-02-21T23:59:59.000Z

373

Energy levels and zero field splitting parameter for Fe{sup 2+} doped in ZnS  

SciTech Connect (OSTI)

The aim of present paper is to report the results on the modeling of the crystal field parameters of Fe{sup 2+} doped in host matrix ZnS, simulate the energy levels scheme and calculate the zero field splitting parameter D of such system. The crystal field parameters were modeled in the frame of the superposition model of crystal field and the simulation of the energy levels scheme and calculation of the zero field splitting parameters done by diagonalization the Hamiltonian of Fe{sup 2+}:ZnS system. The obtained results were disscused and compared with experimental data. Satisfactory agreement have been obtained.

Iva?cu, Simona [Department of Physics, West University of Timisoara, Bd. V. Parvan 4, Timisoara 300223 (Romania)

2013-11-13T23:59:59.000Z

374

Analysis of strained surface layers of ZnO single crystals after irradiation with intense femtosecond laser pulses  

SciTech Connect (OSTI)

Structural modifications of ZnO single crystals that were created by the irradiation with femtosecond laser pulses at fluences far above the ablation threshold were investigated with micro-Raman spectroscopy. After light-matter interaction on the femtosecond time scale, rapid cooling and the pronounced thermal expansion anisotropy of ZnO are likely to cause residual strains of up to 1.8% and also result in the formation of surface cracks. This process relaxes the strain only partially and a strained surface layer remains. Our findings demonstrate the significant role of thermoelastic effects for the irradiation of solids with intense femtosecond laser pulses.

Schneider, Andreas; Sebald, Kathrin; Voss, Tobias [Semiconductor Optics, Institute of Solid State Physics, University of Bremen, D-28359 Bremen (Germany)] [Semiconductor Optics, Institute of Solid State Physics, University of Bremen, D-28359 Bremen (Germany); Wolverson, Daniel [Nanoscience Group, Department of Physics, University of Bath, BA2 7AY Bath (United Kingdom)] [Nanoscience Group, Department of Physics, University of Bath, BA2 7AY Bath (United Kingdom); Hodges, Chris; Kuball, Martin [Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)] [Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

2013-05-27T23:59:59.000Z

375

Search for double beta decay of Zinc and Tungsten with the help of low-background ZnWO4 crystal scintillators  

E-Print Network [OSTI]

Double beta processes in 64-Zn, 70-Zn, 180-W, and 186-W have been searched for with the help of large volume (0.1-0.7 kg) low background ZnWO4 crystal scintillators at the Gran Sasso National Laboratories of the INFN. Total time of measurements exceeds 10 thousands hours. New improved half-life limits on double electron capture and electron capture with positron emission in 64-Zn have been set, in particular (all the limits are at 90% C.L.): T1/2(0nu2EC)> 1.1e20 yr, T1/2(2nuECbeta+)>7.0e20 yr, and T1/2(0nuECbeta+)>4.3e20 yr. The different modes of double beta processes in 70-Zn, 180-W, and 186-W have been restricted at the level of 1e17-1e20 yr.

P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; B. V. Grinyov; A. Incicchitti; V. V. Kobychev; V. M. Mokina; S. S. Nagorny; L. L. Nagornaya; S. Nisi; F. Nozzoli; D. V. Poda; D. Prosperi; V. I. Tretyak; S. S. Yurchenko

2008-11-14T23:59:59.000Z

376

Formation behavior of Be{sub x}Zn{sub 1-x}O alloys grown by plasma-assisted molecular beam epitaxy  

SciTech Connect (OSTI)

We report the phase formation behavior of Be{sub x}Zn{sub 1-x}O alloys grown by plasma-assisted molecular beam epitaxy. We find the alloy with low- and high-Be contents could be obtained by alloying BeO into ZnO films. X-ray diffraction measurements shows the c lattice constant value shrinks, and room temperature absorption shows the energy band-gap widens after Be incorporated. However, the alloy with intermediate Be composition are unstable and segregated into low- and high-Be contents BeZnO alloys. We demonstrate the phase segregation of Be{sub x}Zn{sub 1-x}O alloys with intermediate Be composition resulted from large internal strain induced by large lattice mismatch between BeO and ZnO.

Chen, Mingming; Zhu, Yuan; Su, Longxing; Zhang, Quanlin; Chen, Anqi; Ji, Xu; Xiang, Rong; Gui, Xuchun; Wu, Tianzhun [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)] [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Pan, Bicai [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Tang, Zikang [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China) [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

2013-05-20T23:59:59.000Z

377

Exciton trapping in vibrationally excited organic molecules near a ZnO surface  

E-Print Network [OSTI]

We present a systematic study of the exciton population dynamics at the interface of the spirobifluorene derivative 2,7-bis(biphenyl-4-yl)-2',7'-ditertbutyl-9.9'-spirobifluorene (SP6) and the non-polar (10-10) surface of ZnO, using time-resolved excited state optical transmission spectroscopy. The photoexcited dye first undergoes intramolecular vibrational relaxation in the S1 state on a 2 to 9 ps timescale. Subsequently, the excited state transmission reveals transitions from two distinct vibrational levels of S1, with a lifetime of the vibrationally excited state that is comparable to the one of the vibrational ground state (vGS). The electronic population relaxes by (i) decay to the electronic ground state (ii) transfer to a long-lived dark state that remains populated for longer than 5 microseconds, and (iii) diffusion-limited charge transfer to the ZnO conduction band. Remarkably, the lifetime of the vibratioanlly trapped excition (exciton-vibron) and vGS exciton are not equally affected by a change of s...

Foglia, Laura; Wolf, Martin; Sthler, Julia

2014-01-01T23:59:59.000Z

378

Effects of Ti substitution on structural and magnetic properties of ZnMn ferrospinels  

SciTech Connect (OSTI)

Highlights: ? Novel system ZnMn{sub 1?x}Ti{sub x}FeO{sub 4} synthesized by solgel route. ? Nanocrystalline materials. ? Magnetic materials. - Abstract: Nanocrystalline ZnMn{sub 1?x}Ti{sub x}FeO{sub 4} (1.0 ? x ? 0) ferrites were prepared by solgel route. Formation of single phase cubic spinel structure for all the compositions was confirmed from their X-ray diffraction patterns. The lattice parameter shows an increasing trend with the increase in Ti content. These ferrite samples existed as crystalline nanoparticles of about 3040 nm size as observed from transmission electron microscopy (TEM) technique. EDAX analysis indicated that the concentration of different elements in different compositions is in close agreement with the starting concentrations. Infrared spectra showed two main absorption bands in the range 400800 cm{sup ?1} arising due to tetrahedral (A) and octahedral (B) stretching vibrations. The magnetic studies indicated that, the ferrimagnetic behavior increases with titanium substitution.

Patil, R.P., E-mail: raj_rbm_raj@yahoo.com [Department of Chemistry, Shivaji University, Kolhapur 416004 (India); Patil, N.M. [Department of Chemistry, Shivaji University, Kolhapur 416004 (India); Sasikala, R. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Hankare, P.P., E-mail: p_hankarep@rediffmail.com [Department of Chemistry, Shivaji University, Kolhapur 416004 (India); Delekar, S.D. [Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Sub-campus Osmanabad, 413501 (India)

2013-05-15T23:59:59.000Z

379

SeZnSb alloy and its nano tubes, graphene composites properties  

SciTech Connect (OSTI)

Composite can alter the individual element physical property, could be useful to define the specific use of the material. Therefore, work demonstrates the synthesis of a new composition Se{sub 96}-Zn{sub 2}-Sb{sub 2} and its composites with 0.05% multi-walled carbon nano tubes and 0.05% bilayer graphene, in the glassy form. The diffused amorphous structure of the multi walled carbon nano tubes and bilayer gaphene in the Se{sub 96}-Zn{sub 2}-Sb{sub 2} alloy have been analyzed by using the Raman, X-ray photoluminescence spectroscopy, Furrier transmission infrared spectra, photoluminescence, UV/visible absorption spectroscopic measurements. The diffused prime Raman bands (G and D) have been appeared for the multi walled carbon nano tubes and graphene composites, while the X-ray photoluminescence core energy levels peak shifts have been observed for the composite materials. Subsequently the photoluminescence property at room temperature and a drastic enhancement (upto 80%) in infrared transmission percentage has been obtained for the bilayer graphene composite, along with optical energy band gaps for these materials have been evaluated 1.37, 1.39 and 1.41 eV.

Singh, Abhay Kumar [Department of Physics, Indian Institute of Physics, Bangalore-560012 (India)

2013-04-15T23:59:59.000Z

380

Temperature dependence of photoconductivity in Zn-doped GaN  

SciTech Connect (OSTI)

In agreement with predictions from a model that explained an abrupt thermal quenching of the blue luminescence (BL) band in high-resistivity Zn-doped GaN [Reshchikov et al., Phys. Rev. B 84, 075212 (2011) and Phys. Rev. B 85, 245203 (2012)], we observed the stepwise decrease of photoconductivity in this material with increasing temperature. For the sample studied in this work, the decrease in photoconductivity occurred in two steps at characteristic temperatures T{sub 1} and T{sub 2}. The characteristic temperatures increased with increasing excitation intensity, very similar to the photoluminescence (PL) behavior. The steps in photoconductivity at about 100 K and 200 K are attributed to drop in the concentration of free electrons due to the thermal emission of holes from a shallow acceptor and the Zn{sub Ga} acceptor, respectively, to the valence band and their recombination with electrons via nonradiative centers. This finding supports the model suggested previously and helps to explain other examples of tunable photoconductivity reported in literature.

Reshchikov, Michael A. [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States)

2014-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Nanoassembly control and optical absorption in CdTe-ZnO nanocomposite thin films  

SciTech Connect (OSTI)

The spatial distribution of CdTe nanoparticles within a ZnO thin-film matrix was manipulated using a dual-source, sequential radio-frequency (RF)-sputter deposition technique to produce nanocomposite materials with tuned spectral absorption characteristics. The relative substrate exposure time to each sputtering source was used to control the semiconductor phase connectivity, both within the film plane and along the film growth direction, to influence the degree of photocarrier confinement and the resulting optical transition energies exhibited by the CdTe phase. Significant changes (up to {Delta}E {approx_equal} 0.3 eV) in the absorption onset energy for the CdTe nanoparticle ensemble were produced through modification in the extended structure of the semiconductor phase. Raman spectroscopy, cross-sectional transmission electron microscopy, and x-ray diffraction were used to confirm the phase identity of the CdTe and ZnO and to characterize the nanostructures produced in these composite films. Isochronal annealing for 5 min at temperatures up to 800 deg. C further indicated the potential to improve film crystallinity as well as to establish the post-deposition thermal processing limits of stability for the semiconductor phase. The study highlights the significance of ensemble behavior as a means to influence quantum-scale semiconductor optical characteristics of import to the use of such materials as the basis for a variety of optoelectronic devices, including photosensitized heterojunction components in thin film photovoltaics.

Potter, B. G. Jr. [Materials Science and Engineering Department, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States); Beal, R. J.; Allen, C. G. [Materials Science and Engineering Department, University of Arizona, Tucson, Arizona 85721 (United States)

2012-02-01T23:59:59.000Z

382

Experimental and theoretical study of the energy loss of C and O in Zn  

SciTech Connect (OSTI)

We present a combined experimental-theoretical study of the energy loss of C and O ions in Zn in the energy range 50-1000 keV/amu. This contribution has a double purpose, experimental and theoretical. On the experimental side, we present stopping power measurements that fill a gap in the literature for these projectile-target combinations and cover an extended energy range, including the stopping maximum. On the theoretical side, we make a quantitative test on the applicability of various theoretical approaches to calculate the energy loss of heavy swift ions in solids. The description is performed using different models for valence and inner-shell electrons: a nonperturbative scattering calculation based on the transport cross section formalism to describe the Zn valence electron contribution, and two different models for the inner-shell contribution: the shellwise local plasma approximation (SLPA) and the convolution approximation for swift particles (CasP). The experimental results indicate that C is the limit for the applicability of the SLPA approach, which previously was successfully applied to projectiles from H to B. We find that this model clearly overestimates the stopping data for O ions. The origin of these discrepancies is related to the perturbative approximation involved in the SLPA. This shortcoming has been solved by using the nonperturbative CasP results to describe the inner-shell contribution, which yields a very good agreement with the experiments for both C and O ions.

Cantero, E. D.; Lantschner, G. H.; Arista, N. R. [Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina); Montanari, C. C.; Miraglia, J. E. [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA), Buenos Aires (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina); Behar, M.; Fadanelli, R. C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, Porto Alegre-RS (Brazil)

2011-07-15T23:59:59.000Z

383

Magnetoresistance in Mn ion-implanted GaAs:Zn nanowires  

SciTech Connect (OSTI)

We have investigated the magnetoresistance (MR) in a series of Zn doped (p-type) GaAs nanowires implanted with different Mn concentrations. The nanowires with the lowest Mn concentration (?0.0001%) exhibit a low resistance of a few k? at 300?K and a 4% positive MR at 1.6?K, which can be well described by invoking a spin-split subband model. In contrast, nanowires with the highest Mn concentration (4%) display a large resistance of several M? at 300?K and a large negative MR of 85% at 1.6?K. The large negative MR is interpreted in terms of spin-dependent hopping in a complex magnetic nanowire landscape of magnetic polarons, separated by intermediate regions of Mn impurity spins. Sweeping the magnetic field back and forth for the 4% sample reveals a hysteresis that indicates the presence of a weak ferromagnetic phase. We propose co-doping with Zn to be a promising way to reach the goal of realizing ferromagnetic Ga{sub 1?x}Mn{sub x}As nanowires for future nanospintronics.

Paschoal, W.; Kumar, Sandeep; Jain, V.; Pettersson, H., E-mail: hakan.pettersson@hh.se [Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund (Sweden); Department of Mathematics, Physics and Electrical Engineering, Halmstad University, Box 823, SE-301 18, Halmstad (Sweden); Jacobsson, D.; Samuelson, L. [Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund (Sweden); Johannes, A.; Ronning, C. [Institute for Solid State Physics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Canali, C. M.; Pertsova, A. [Department of Physics and Electrical Engineering, Linneaus University, SE-39233 Kalmar (Sweden); Dick, K. A. [Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund (Sweden); Center for Analysis and Synthesis, Lund University, Box 124, S-221 00 Lund (Sweden)

2014-04-14T23:59:59.000Z

384

Rejection of randomly coinciding events in ZnMoO$_4$ scintillating bolometers  

E-Print Network [OSTI]

Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and $\\chi^2$ methods was applied to discriminate randomly coinciding events in ZnMoO$_4$ cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99% by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92% by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95% of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of $^{100}$Mo for enriched ZnMoO$_4$ detectors, of the order of $10^{-4}$ counts/(y keV kg). Pulse-shape parameters ...

Chernyak, D M; Giuliani, A; Mancuso, M; Nones, C; Olivieri, E; Tenconi, M; Tretyak, V I

2014-01-01T23:59:59.000Z

385

In-situ study of discontinuous precipitation in Al-15 at.% Zn  

SciTech Connect (OSTI)

In the present study, attention was focused on in-situ work on discontinuous precipitation in Al-15.0 at.% Zn in a high voltage electron microscope using a hot stage and a video system. The microscope was an AEI instrument with a maximum voltage of 1.25 MV. The voltage used was 500 kV. The scope of the present study was to check if the grain boundary migration in the discontinuous precipitation reaction proceeds in a stop-and-go fashion. From all the observations reported here it can be concluded that the stop-and-go type of grain boundary migration seems to be a very general one. But in many cases it cannot easily experimentally be proved. In case of discontinuous precipitation in Al-15.0 at.% Zn it has been clearly demonstrated by in-situ observations in a high-voltage electron microscope that the reaction front migration occurs in a stop-and-go fashion. Consequently, there is a drastic difference between the average velocity and the instantaneous velocity. The only quantity, which can be determined in traditional experiments, is the average velocity to which the Petermann-Hornbogen equation is adequate.

Abdou, S.; El-Boragy, M. [Suez Canal Univ., Port Said (Egypt). Faculty of Engineering] [Suez Canal Univ., Port Said (Egypt). Faculty of Engineering; Solorzano, G. [PUC-RJ, Rio de Janeiro (Brazil). Dept. of Metallurgy and Materials Science] [PUC-RJ, Rio de Janeiro (Brazil). Dept. of Metallurgy and Materials Science; Gust, W.; Predel, B. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany)] [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany); [Institut fuer Metallkunde der Universitaet, Stuttgart (Germany)

1996-05-01T23:59:59.000Z

386

Cu2ZnSnS x O4 x and Cu2ZnSnS x Se4 x : First principles simulations of optimal alloy configurations and their energies  

E-Print Network [OSTI]

is the development of thin film photovoltaic devices with high effi- ciency and low cost. As an absorber layer) photovoltaic absorber layer material J. Appl. Phys. 112, 124508 (2012); 10.1063/1.4769738 Analysis of lattice and selenization of the photovoltaic material Cu2ZnSnS4, we used first principles methods to study the structure

Holzwarth, Natalie

387

Thermal ionization induced metal-semiconductor transition and room temperature ferromagnetism in trivalent doped ZnO codoped with lithium  

SciTech Connect (OSTI)

Thermal ionization induced metallic to semiconductor (MST) transition occurring at 460?K for Zn{sub 0.97}Al{sub 0.03}O, 463?K for Zn{sub 0.94}Al{sub 0.03}Li{sub 0.03}O, and 503?K for Zn{sub 0.91}Al{sub 0.03}Li{sub 0.03}Mn{sub 0.03}O has been found in the sol-gel synthesized (using hexamethylenetetramine), trivalent doped (Al, Mn) ZnO codoped with lithium. Increase in the thermally ionized carrier concentration due to Al doping is responsible for near band edge (NBE) peak shift causing Fermi level to move into conduction band making it metallic consistent with resistivity results. Free carrier (thermally activated) neutralization with ionized donor is responsible for semiconducting nature, which is supported from the free carrier screening produced energy shift in the NBE of photoluminescence peak. Furthermore, independently band gap shrinkage is also obtained from UV-Visible studies confirming localization induced MST. An anti-correlation is found between defect density (DLE) and room temperature ferromagnetism (RTFM) indicating intrinsic defects are not directly responsible for RTFM.

Sivagamasundari, A.; Chandrasekar, S.; Pugaze, R.; Kannan, R., E-mail: kannan@pec.edu [Department of Physics, Pondicherry Engineering College, Puducherry 605 014 (India); Rajagopan, S. [Department of Chemistry, Pondicherry Engineering College, Puducherry 605 014 (India)

2014-03-07T23:59:59.000Z

388

Highly efficient flexible inverted organic solar cells using atomic layer deposited ZnO as electron selective layer  

E-Print Network [OSTI]

advancements, the power conversion efficiency (PCE) of organic solar cells (OSCs) has been improved with PCE more than 4% was demonstrated.7 However,Cs2CO3 exhibitsdeliquescencewhichaffects severely a PCE of 3.09%.14 Hau et al. adopted spin-coated ZnO nanoparticles as the electron selective layer

389

Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite  

E-Print Network [OSTI]

Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite K. Zehani Plasma Sintering is a powerfal method to produce fine grain dense ferrite at low temperature. However.75.Cd, 81.20.Ev, 81.40.Rs Keywords: Spark Plasma Sintering, Spinel ferrite, Grain size, Complex real

390

Microstructure, mechanical property and corrosion behaviors of interpenetrating C/Mg-Zn-Mn composite fabricated by suction casting  

E-Print Network [OSTI]

bonding between Mg-Zn-Mn alloy and carbon scaffold was very well. The composite had an ultimate. Introduction Carbon, in all its forms, such as carbon nanotubes, carbon fabric, carbon-carbon composites, glassy carbon, pyrocarbons and diamond- like layers, is considered as a promising material for biomedical

Zheng, Yufeng

391

Laser irradiation effects on the CdTe/ZnTe quantum dot structure studied by Raman and AFM spectroscopy  

SciTech Connect (OSTI)

Micro-Raman spectroscopy has been applied to investigate the impact of laser irradiation on semiconducting CdTe/ZnTe quantum dots (QDs) structures. A reference sample (without dots) was also studied for comparison. Both samples were grown by molecular beam epitaxy technique on the p-type GaAs substrate. The Raman spectra have been recorded for different time of a laser exposure and for various laser powers. The spectra for both samples exhibit peak related to the localized longitudinal (LO) ZnTe phonon of a wavenumber equal to 210 cm{sup -1}. For the QD sample, a broad band corresponding to the LO CdTe phonon related to the QD-layer appears at a wavenumber of 160 cm{sup -1}. With increasing time of a laser beam exposure and laser power, the spectra get dominated by tellurium-related peaks appearing at wavenumbers around 120 cm{sup -1} and 140 cm{sup -1}. Simultaneously, the ZnTe surface undergoes rising damage, with the formation of Te aggregates at the pinhole edge as reveal atomic force microscopy observations. Local temperature of irradiated region has been estimated from the anti-Stokes/Stokes ratio of the Te modes intensity and it was found to be close or exceeding ZnTe melting point. Thus, the laser damage can be explained by the ablation process.

Zielony, E.; Placzek-Popko, E.; Henrykowski, A.; Gumienny, Z.; Kamyczek, P.; Jacak, J. [Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Nowakowski, P.; Karczewski, G. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland)

2012-09-15T23:59:59.000Z

392

InAs(ZnCdS) Quantum Dots Optimized for Biological Imaging in the Near-Infrared  

E-Print Network [OSTI]

We present the synthesis of InAs quantum dots (QDs) with a ZnCdS shell with bright and stable emission in the near-infrared (NIR, 700?900 nm) region for biological imaging applications. We demonstrate how NIR QDs can image ...

Allen, Peter M.

393

Dynamics of charge transport and recombination in ZnO nanorod array dye-sensitized solar cells  

E-Print Network [OSTI]

Dynamics of charge transport and recombination in ZnO nanorod array dye-sensitized solar cells Alex nanoparticles. Introduction Dye-Sensitized Solar Cells (DSSCs) comprise an increasingly attractive alternative photovoltaic technology.1,2 These photo- electrochemical cells use molecular dyes to sensitize high-area, wide

394

ZnO Nanostructures for Dye-Sensitized Solar Cells By Qifeng Zhang,* Christopher S. Dandeneau, Xiaoyuan Zhou, and  

E-Print Network [OSTI]

ZnO Nanostructures for Dye-Sensitized Solar Cells By Qifeng Zhang,* Christopher S. Dandeneau-low cost (US$0.40 kWh?1 ).[1] To aim at further lowering the production costs, dye-sensitized solar cells, such as solar cells, fuel cells, and biofuels. However, although these alternative energy sources have been

Cao, Guozhong

395

Nanostructural analysis of ZnO:Al thin films for carrier-transport Seung-Yoon Lee a,b  

E-Print Network [OSTI]

Il Jang a , Sungeun Lee a , Heon-Min Lee a , Byungwoo Park b,* a Emerging Technology Laboratory, LG Electronics Advanced Research Institute, Seoul 137-724, Republic of Korea b WCU Hybrid Materials Program important research themes. Carrier-transport mechanisms for the electron mobility of doped ZnO thin films

Park, Byungwoo

396

UV-blocking ZnO nanostructure anti-reflective coatings Qing Guo Du a,b  

E-Print Network [OSTI]

layer for solar energy applications. According to these two properties, ZnO nanostructures can be used are essential parts for high ef- ficiency and low cost solar cell devices especially for thin film solar cell some problems such as ma- terial selection, thermal mismatch, sensitivity to thickness variation

Demir, Hilmi Volkan

397

Zn Sorption Mechanisms onto Sheathed Leptothrix Discophora and the Impact of the Nanoparticulate Biogenic Mn Oxide Coating  

SciTech Connect (OSTI)

Zinc sorption on sheathed Leptothrix discophora bacterium, the isolated extracellular polymeric substances (EPS) sheath, and Mn oxide-coated bacteria was investigated with macroscopic and spectroscopic techniques. Complexation with L. discophora was dominated by the outer membrane phosphoryl groups of the phospholipid bilayer while sorption to isolated EPS was dominated by carboxyl groups. Precipitation of nanoparticulate Mn oxide coatings on the cell surface increased site capacity by over twenty times with significant increase in metal sorption. XAS analysis of Zn sorption in the coated system showed Mn oxide phase contributions of 18 to 43% through mononuclear inner-sphere complexes. The coordination environments in coprecipitation samples were identical to those of sorption samples, indicating that, even in coprecipitation, Zn is not incorporated into the Mn oxide structure. Rather, through enzymatic oxidation by L. discophora, Mn(II) is oxidized and precipitated onto the biofilm providing a large surface for metal sequestration. The nanoparticulate Mn oxide coating exhibited significant microporosity (75%) suggesting contributions from intraparticle diffusion. Transient studies conducted over 7 months revealed a 170% increase in Zn loading. However, the intraparticle diffusivity of 10{sup -19} cm{sup 2} s{sup -1} is two orders of magnitude smaller than that for abiotic Mn oxide which we attribute to morphological changes such as reduced pore sizes in the nanoparticulate oxide. Our results demonstrate that the cell-bound Mn oxide particles can sorb significant amounts of Zn over long periods of time representing an important surface for sequestration of metal contaminants.

Boonfueng, T.; Axe, L; Yee, N; Hahn, D; Ndiba, P

2009-01-01T23:59:59.000Z

398

Bioaccumulation of essential metals (Co, Mn and Zn) in the king scallop Pecten maximus: seawater, food and sediment exposures  

E-Print Network [OSTI]

, food and sediment exposures Marc Metiana,b , Michel Warnaua* , Laetitia Hédouina,b , Paco Bustamanteb-feeding mollusks living in soft sediments, the uptake and depuration kinetics of three elements (Co, Mn and Zn) were investigated in the king scallop Pecten maximus exposed via seawater, food, or sediment, using

Boyer, Edmond

399

Mechanochemical synthesis of tungsten carbide nano particles by using WO{sub 3}/Zn/C powder mixture  

SciTech Connect (OSTI)

Graphical abstract: Display Omitted Highlights: ? Nano particles of WC are synthesized by mechanochemical process. ? Zn was used to reduce WO{sub 3}. ? By removing ZnO from the milling products with an acid leaching, WC will be the final products. ? XRD results showed that the reduction reactions were completed after 36 h. ? TEM and SEM images showed that the morphology of produced powder is nearly spherical like. -- Abstract: In this research we introduce a new, facile, and economical system for fabrication of tungsten carbide (WC) nano particle powder. In this system WO{sub 3}, Zn, and C have been ball-milled for several hours, which led to the synthesis of tungsten carbide nano particles. The synthesized WC can successfully be separated from the ball-milled product by subjecting the product powder to diluted HCl for removing ZnO and obtaining WC. X-ray diffraction (XRD) analysis indicates that the reduction of WO{sub 3} will be completed gradually by increasing milling time up to 36 h. Scanning electron microscope (SEM), and transmission electron microscope (TEM) images show that after 36 h of milling the particle size of the fabricated powder is nano metric (about 20 nm). Results have shown that this system can surmount some main problems occurred in previous similar WC synthesizing systems. For example carbothermic reduction reactions, which lead to the synthesis of W{sub 2}C instead of WC, would not be activated because in this system reactions take place gradually.

Hoseinpur, Arman, E-mail: arman.hoseinpur@stu-mail.um.ac.ir [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of)] [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of); Vahdati Khaki, Jalil; Marashi, Maryam Sadat [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of)] [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of)

2013-02-15T23:59:59.000Z

400

CHOPPING VERSUS GRINDING AND PELLETING OF HAY : EFFECT ON AVAILABILITY OF TRACE ELEMENTS (Cu, Zn and Mn)  

E-Print Network [OSTI]

CHOPPING VERSUS GRINDING AND PELLETING OF HAY : EFFECT ON AVAILABILITY OF TRACE ELEMENTS (Cu, Zn often receive ground diets that may or may not be pelleted. We intended to examine the effect of transit) chopped into pieces 3 cm long, or ground in a grinder equipped with a 0.6 mm sieve and pelleted in 6 mm

Boyer, Edmond

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Adsorption and Diffusion of Hydrogen in a New Metal-Organic Framework Material: [Zn(bdc)(ted)0.5  

E-Print Network [OSTI]

Adsorption and Diffusion of Hydrogen in a New Metal-Organic Framework Material: [Zn(bdc)(ted)0. Sankar,§ and J. Karl Johnson*,,| Department of Chemical Engineering, UniVersity of Pittsburgh, Pittsburgh: NoVember 29, 2007 We have experimentally measured hydrogen isotherms at 77 and 298 K up to a hydrogen

Li, Jing

402

Development of ZnNiCd coatings by pulse electrodeposition process Prabhu Ganesan, Swaminatha P. Kumaraguru, Branko N. Popov  

E-Print Network [OSTI]

Development of ZnNiCd coatings by pulse electrodeposition process Prabhu Ganesan, Swaminatha P form 22 August 2006 Available online 6 October 2006 Abstract A pulse electrodeposition process. An increase in average current density resulted in a decrease in both nickel and cadmium content in the alloy

Popov, Branko N.

403

Quantifying oxygen diffusion in ZnO nanobelt Jin Liu, Puxian Gao, Wenjie Mai, Changshi Lao, and Zhong L. Wanga  

E-Print Network [OSTI]

Quantifying oxygen diffusion in ZnO nanobelt Jin Liu, Puxian Gao, Wenjie Mai, Changshi Lao A method is presented for quantifying oxygen diffusion behavior in a nanodevice fabricated using individual for several days, oxygen in air diffused into the nanobelt and significantly changed the conductivity

Wang, Zhong L.

404

Trap and recombination centers study in sprayed Cu{sub 2}ZnSnS{sub 4} thin films  

SciTech Connect (OSTI)

In this work, a study of trap and recombination center properties in polycrystalline Cu{sub 2}ZnSnS{sub 4} thin films is carried out in order to understand the poor performance in Cu{sub 2}ZnSnS{sub 4} thin film solar cells. Thermally stimulated current has been studied in Cu{sub 2}ZnSnS{sub 4} deposited by pneumatic spray pyrolysis method using various heating rates, in order to gain information about trap centers and/or deep levels present within the band-gap of this material. A set of temperature-dependent current curves revealed three levels with activation energy of 126??10, 476??25, and 1100??100?meV. The possible nature of the three levels found is presented, in which the first one is likely to be related to Cu{sub Zn} antisites, while second and third to Sn vacancies and Sn{sub Cu} antisites, respectively. The values of frequency factor, capture cross section, and trap concentration have been determined for each center.

Courel, Maykel, E-mail: maykelcourel@gmail.com; Vigil-Galn, O.; Jimnez-Olarte, D. [Escuela Superior de Fsica y Matemticas-Instituto Politcnico Nacional (IPN), C.P. 07738, Mxico DF (Mexico); Espndola-Rodrguez, M. [Escuela Superior de Fsica y Matemticas-Instituto Politcnico Nacional (IPN), C.P. 07738, Mxico DF (Mexico); Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adri de Bess, Barcelona (Spain); Saucedo, E. [Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adri de Bess, Barcelona (Spain)

2014-10-07T23:59:59.000Z

405

Monolithic multichannel ultraviolet detector arrays and continuous phase evolution in MgxZn1xO composition spreads  

E-Print Network [OSTI]

American Institute of Physics. DOI: 10.1063/1.1623923 I. INTRODUCTION ZnO is a wide band gap semiconductor whose potential device applications include UV lasers,1,2 transparent con- ducting films for solar cells simultaneously is central in today's photonics tech- nology. In order to detect signals at discrete wavelengths

Rubloff, Gary W.

406

Synthesis of Mixed Ceramic MgxZn1-xO Nanofibers via Mg2+ Using Sol-Gel Electrospinning  

E-Print Network [OSTI]

acetate (MgAc) and zinc acetate (ZnAc) with poly(vinyl alcohol) (PVA), electrospinning is performed and then as- spun nanofibers are calcined in an air atmosphere at 600 C for 3 h. As-spun and calcined are promising candidates for various usage, from batteries to solar cells and catalysts. Sol-gel electrospinning

Khan, Saad A.

407

drinking water. On the basis of the volume of ZnS precipitated in the biofilm, we estimate  

E-Print Network [OSTI]

drinking water. On the basis of the volume of ZnS precipitated in the biofilm, we estimate, 647 (1964). 6. W. J. Drury, Water Environ. Res. 71, 1244 (1999). 7. U.S. Environmental Protection Agency, Office of Ground Water and Drinking Water, Current Drinking Water Standards (2000). 8

Kurapov, Alexander

408

Mineralogical heterogeneities in the Earth's mantle: Constraints from Mn, Co, Ni and Zn partitioning during partial melting  

E-Print Network [OSTI]

Mineralogical heterogeneities in the Earth's mantle: Constraints from Mn, Co, Ni and Zn online 1 June 2011 Editor: L. Stixrude Keywords: transition metals mineralogical heterogeneities are sensitive to changes in mineralogy or major element composition, and thus, are promising to trace

Lee, Cin-Ty Aeolus

409

PHYSICAL REVIEW B 84, 035313 (2011) Bound excitons in ZnO: Structural defect complexes versus shallow impurity centers  

E-Print Network [OSTI]

activation energy and localization energy of the excitons and cannot be described by an effective mass centers is visualized in contrast to the homogeneous distribution of shallow impurity centers toward the development of a large ZnO based market for light emitting devices. The main requirements

Nabben, Reinhard

2011-01-01T23:59:59.000Z

410

Effects of Temperature on the Relative Toxicities of Cd, Cu, Pb, and Zn to Folsomia candida (Collembola)  

E-Print Network [OSTI]

for cadmium, copper, lead, and zinc were determined for juvenile production of Folsomia candida Willem, 1902-1 ) for cadmium, copper, and zinc were similar at both 20 and 15°C (20°C: Cd, 590; Cu, 700; Zn, 900, 2790; 15°C: Pb, 1570). In aerially contaminated field sites adjacent to primary zinc smelters, zinc

Hopkin, Steve

411

Tuning of deep level emission in highly oriented electrodeposited ZnO nanorods by post growth annealing treatments  

SciTech Connect (OSTI)

Highly dense and c-axis oriented zinc oxide (ZnO) nanorods with hexagonal wurtzite facets were deposited on fluorine doped tin oxide coated glass substrates by a simple and cost-effective electrodeposition method at low bath temperature (80?C). The as-grown samples were then annealed at various temperatures (T{sub A}?=?100500?C) in different environments (e.g., zinc, oxygen, air, and vacuum) to understand their photoluminescence (PL) behavior in the ultra-violet (UV) and the visible regions. The PL results revealed that the as-deposited ZnO nanorods consisted of oxygen vacancy (V{sub O}), zinc interstitial (Zn{sub i}), and oxygen interstitial (O{sub i}) defects and these can be reduced significantly by annealing in different environments at optimal annealing temperatures. However, the intensity of deep level emission increased for T{sub A} greater than the optimized values for the respective environments due to the introduction of various defect centers. For example, for T{sub A}???450?C in the oxygen and air environments, the density of O{sub i} defects increased, whereas, the green emission associated with V{sub O} is dominant in the vacuum annealed (T{sub A}?=?500?C) ZnO nanorods. The UV peak red shifted after the post-growth annealing treatments in all the environments and the vacuum annealed sample exhibited highest UV peak intensity. The observations from the PL data are supported by the micro-Raman spectroscopy. The present study gives new insight into the origin of different defects that exist in the electrodeposited ZnO nanorods and how these defects can be precisely controlled in order to get the desired emissions for the opto-electronic applications.

Simimol, A. [Nanomaterials Research Laboratory, Surface Engineering Division CSIR-National Aerospace Laboratories, Post Bag No. 1779, Bangalore 560017 (India); Department of Physics, National Institute of Technology, Calicut 673601 (India); Manikandanath, N. T.; Chowdhury, Prasanta; Barshilia, Harish C., E-mail: harish@nal.res.in [Nanomaterials Research Laboratory, Surface Engineering Division CSIR-National Aerospace Laboratories, Post Bag No. 1779, Bangalore 560017 (India); Anappara, Aji A. [Department of Physics, National Institute of Technology, Calicut 673601 (India)

2014-08-21T23:59:59.000Z

412

Co-assembly of Zn(SPh){sub 2} and organic linkers into helical and zig-zag polymer chains  

SciTech Connect (OSTI)

Two novel one-dimensional coordination polymers, single helicate [Zn(SPh){sub 2}(TPyTA)(EG)]{sub n} (EG=ethylene glycol) (1) and zig-zag structure [Zn(SPh){sub 2}(BPyVB)]{sub n} (2), were synthesized under solvothermal conditions at 150 Degree-Sign C or room temperature by the co-assembly of Zn(SPh){sub 2} and organic linkers such as 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPyTA) and 1,3-bis(trans-4-pyridylvinyl)benzene (BPyVB). X-ray crystallography study reveals that both polymers 1 and 2 crystallize in space group P2{sub 1}/c of the monoclinic system. The solid-state UV-vis absorption spectra show that 1 and 2 have maxium absorption onsets at 400 nm and 420 nm, respectively. TGA analysis indicates that 1 and 2 are stable up to 110 Degree-Sign C and 210 Degree-Sign C. - Graphical abstract: Two novel one-dimensional coordination polymers, single helicate [Zn(SPh){sub 2}(TPyTA)(EG)]{sub n} (1) and zig-zag structure [Zn(SPh){sub 2}(BPyVB)]{sub n} (2), were synthesized. Solid-state UV-vis absorptions show that 1 and 2 have maxium absorption onsets at 400 nm and 420 nm, respectively. TGA analysis indicates that 1 and 2 are stable up to 110 Degree-Sign C and 210 Degree-Sign C. Highlights: Black-Right-Pointing-Pointer Two novel one-dimensional coordination polymers have been synthesized. Black-Right-Pointing-Pointer TPyTA results in helical structures in 1 while BPyVB leads to zig-zag chains in 2. Black-Right-Pointing-Pointer Solid-state UV-vis absorption spectra and TGA analysis of the title polymers were studied.

Liu Yi; Yu Lingmin; Loo, Say Chye Joachim [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Blair, Richard G. [Chemistry and Forensic Science, University of Central Florida, Department of Chemistry, 4000 Central Florida Blvd. P.O. Box 162366, Orlando, FL 32816-2366 (United States); Zhang Qichun, E-mail: qczhang@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2012-07-15T23:59:59.000Z

413

The use of novel biodegradable, optically active and nanostructured poly(amide-ester-imide) as a polymer matrix for preparation of modified ZnO based bionanocomposites  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer A novel biodegradable and nanostructured PAEI based on two amino acids, was synthesized. Black-Right-Pointing-Pointer ZnO nanoparticles were modified via two different silane coupling agents. Black-Right-Pointing-Pointer PAEI/modified ZnO BNCs were synthesized through ultrasound irradiation. Black-Right-Pointing-Pointer ZnO particles were dispersed homogeneously in PAEI matrix on nanoscale. Black-Right-Pointing-Pointer The effect of ZnO nanoparticles on the properties of synthesized polymer was examined. -- Abstract: A novel biodegradable and nanostructured poly(amide-ester-imide) (PAEI) based on two different amino acids, was synthesized via direct polycondensation of biodegradable N,N Prime -bis[2-(methyl-3-(4-hydroxyphenyl)propanoate)]isophthaldiamide and N,N Prime -(pyromellitoyl)-bis-L-phenylalanine diacid. The resulting polymer was characterized by FT-IR, {sup 1}H NMR, specific rotation, elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analysis. The synthesized polymer showed good thermal stability with nano and sphere structure. Then PAEI/ZnO bionanocomposites (BNCs) were fabricated via interaction of pure PAEI and ZnO nanoparticles. The surface of ZnO was modified with two different silane coupling agents. PAEI/ZnO BNCs were studied and characterized by FT-IR, XRD, UV/vis, FE-SEM and TEM. The TEM and FE-SEM results indicated that the nanoparticles were dispersed homogeneously in PAEI matrix on nanoscale. Furthermore the effect of ZnO nanoparticle on the thermal stability of the polymer was investigated with TGA and DSC technique.

Abdolmaleki, Amir, E-mail: abdolmaleki@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of) [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Mallakpour, Shadpour, E-mail: mallak@cc.iut.ac.ir [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of) [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Borandeh, Sedigheh [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of)] [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of)

2012-05-15T23:59:59.000Z

414

Factors affecting initial permeability of Co-substituted Ni-Zn-Cu ferrites  

SciTech Connect (OSTI)

Iron deficient compositions of (Ni{sub 0.2}Cu{sub 0.2}Zn{sub 0.6}){sub 1.02{minus}x}Co{sub x}Fe{sub 1.98}O{sub 4} (0 {le} x {le} 0.05) were prepared to investigate their initial permeability dependence on cobalt contents. Extrinsic factors such as grain size and sintered density change little in samples sintered at 900 C, so their effects on permeability can be neglected. Intrinsic factors such as saturation magnetization, magnetocrystalline anisotropy (K{sub 1}) and magnetoelastic anisotropy (K{sub {sigma}}) can not account for the variation of initial permeability with Co content. Measurement of thermoelectric power shows that the concentration of cation vacancies increases with Co content. Therefore, the local induced anisotropy increases by the ordering of Co ions cia increased cation vacancy concentration. This increase in induced anisotropy results in the decrease of initial permeability.

Byun, T.Y.; Byeon, S.C.; Hong, K.S.; Kim, C.K.

1999-09-01T23:59:59.000Z

415

Effect of ultrasonic treatment on tensile properties of PLA/LNR/NiZn ferrite nanocomposite  

SciTech Connect (OSTI)

The influence of sonication treatment time on the morphological and mechanical properties of LNR/PLA composite impregnated with different filler loadings of NiZn ferrite nanoparticles was investigated. The nanocomposite was prepared using melt blending method with assistance of ultrasonic treatment of 0, 1 and 2 hrs. Structural characterization of the nanocomposites was examined using scanning electron microscopy (SEM) with their elemental composition being confirmed by energy dispersive X-ray spectroscopy (EDX). The tensile properties of LNR/PLA composite treated with different ultrasonication times have improved with increasing magnetic nanofiller signature in the nanocomposite. Further, the optimum sonication time of 1 hr was found to produce nanocomposite with maximum tensile properties.

Shahdan, Dalila; Ahmad, Sahrim Hj.; Flaifel, Moayad Husein [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2013-11-27T23:59:59.000Z

416

Role of sonic energy on growth morphology and optical properties of ZnO:S nanostructures  

SciTech Connect (OSTI)

ZnO nanopowders doped with sulphur were prepared by sonochemical method. The input power of ultrasound was varied as 40%, 50% and 60% of the maximum power (375 W) in both continuous and pulsed mode. XRD results show the average size of the nanoparticles is the least for those prepared with 50% input power as well as the micro-strain. FESEM studies showed the formation of nanorods clubbed together to form flower like structure for these samples. In rest of the cases, no definite morphology was obtained. High resolution transmission electron microscopy (HRTEM) reveals the formation of nanorods oriented along c-axis for those samples prepared with 50% input power. No cavitation at 40% and excessive dissolution at 60% may lead to this type of morphology. Absorption studies showed high absorbance for sulphur doped samples but this was highest for the samples prepared with 60% input power.

Panda, Nihar Ranjan, E-mail: niharphysics@yahoo.co.in; Nayak, Pratibindhya [School of Physics, Sambalpur University, Jyoti Vihar, Burla-768019, Odisha (India); Acharya, Bhabani Shankar [C.V. Raman College of Engineering, Bhubaneswar-752054, Odisha (India)

2014-04-24T23:59:59.000Z

417

Enhanced stimulated emission in ZnO thin films using microdisk top-down structuring  

SciTech Connect (OSTI)

Microdisks were fabricated in zinc oxide (ZnO) thin films using a top-down approach combining electron beam lithography and reactive ion etching. These microdisk structured thin films exhibit a stimulated surface emission between 3 and 7 times higher than that from a reference film depending on the excitation power density. Emission peak narrowing, reduction in lasing threshold and blue-shifting of the emission wavelength were observed along with enhancement in the emitted intensity. Results indicate that this enhancement is due to an increase in the internal quantum efficiency combined with an amplification of the stimulated emission. An analysis in terms of waveguiding is presented in order to explain these effects. These results demonstrate that very significant gains in emission can be obtained through conventional microstructuration without the need for more onerous top-down nanostructuration techniques.

Nomenyo, K.; Kostcheev, S.; Lrondel, G. [Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, CNRS UMR 6281, Universit de Technologie de Troyes, 12 rue Marie Curie, CS 42060, 10004 Troyes Cedex (France); Gadallah, A.-S. [Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, CNRS UMR 6281, Universit de Technologie de Troyes, 12 rue Marie Curie, CS 42060, 10004 Troyes Cedex (France); Department of Laser Sciences and Interactions, National Institute of Laser Enhanced Sciences, Cairo University, Giza (Egypt); Rogers, D. J. [Nanovation, 8, route de Chevreuse, 78117 Chteaufort (France)

2014-05-05T23:59:59.000Z

418

Crucial role of implanted atoms on dynamic defect annealing in ZnO  

SciTech Connect (OSTI)

Processes of defect formation in radiation hard semiconductors exhibiting efficient dynamic annealing are different from those in amorphizible ones, and the latter are generally more well-studied. In the present work, we investigate structural disorder in wurtzite ZnO, which is a radiation hard material, implanted with different ions at room temperature and 15?K. The sample analysis was undertaken by Rutherford backscattering/channeling spectrometry performed in-situ without changing the sample temperature. The fluence dependence of bulk disorder exhibits the so-called IV-stage evolution, where the high fluence regime is characterized by both a strong influence on the damage build-up by the ion type and a reverse temperature effect. A straightforward methodology is demonstrated to differentiate between the contributions of pure ballistic and ion-defect reaction processes in the damage formation.

Azarov, A. Yu.; Kuznetsov, A. Yu.; Svensson, B. G. [Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Wendler, E. [Friedrich-Schiller-Universitt Jena, Institut fr Festkrperphysik, Max-Wien-Platz 1, 07743 Jena (Germany)

2014-02-03T23:59:59.000Z

419

Co-Evaporated Cu2ZnSnSe4 Films and Devices  

SciTech Connect (OSTI)

The use of vacuum co-evaporation to produce Cu2ZnSnSe4 photovoltaic devices with 9.15% total-area efficiency is described. These new results suggest that the early success of the atmospheric techniques for kesterite photovoltaics may be related to the ease with which one can control film composition and volatile phases, rather than a fundamental benefit of atmospheric conditions for film properties. The co-evaporation growth recipe is documented, as is the motivation for various features of the recipe. Characteristics of the resulting kesterite films and devices are shown in scanning electron micrographs, including photoluminescence, current-voltage, and quantum efficiency. Current-voltage curves demonstrate low series resistance without the light-dark cross-over seen in many devices in the literature. Band gap indicated by quantum efficiency and photoluminescence is roughly consistent with that expected from first principles calculation.

Repins, I.; Beall, C.; Vora, N.; DeHart, C.; Kuciauskas, D.; Dippo, P.; To, B.; Mann, J.; Hsu, W. C.; Goodrich, A.; Noufi, R.

2012-06-01T23:59:59.000Z

420

A process for the chemical preparation of high-field ZnO varistors  

DOE Patents [OSTI]

Chemical preparation techniques involving co-precipitation of metals are used to provide microstructural characteristics necessary in order to produce ZnO varistors and their precursors for high field applications. The varistors produced have homogeneous and/or uniform dopant distributions and a submicron average grain size with a narrow size distribution. Precursor powders are prepared via chemical precipitation techniques and varistors made by sintering uniaxially and/or isostatically pressed pellets. Using these methods, varistors were made which were suitable for high-power applications, having values of breakdown field, E/sub B/, in the 10 to 100 kV/cm range, ..cap alpha.. > 30 and densities in the range of 65 to 99% of theoretical, depending on both composition and sintering temperature.

Brooks, R.A.; Dosch, R.G.; Tuttle, B.A.

1986-02-19T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Generation and recombination rates at ZnTe:O intermediate band states  

SciTech Connect (OSTI)

Carrier generation and recombination processes of ZnTeO thin films are studied by time-resolved photoluminescence, where carrier lifetimes at oxygen states and the conduction band are inferred to be >1??s and <100?ps, respectively. The radiative recombination coefficient for optical transitions from oxygen states to the valence band is extracted to be 1.210{sup ?10}?cm{sup 3}?sec{sup ?1} based on the excitation dependence of decay time constants. Rate equation analysis further suggests an increase in electron lifetime at the conduction band as oxygen states occupation is critical in achieving high conversion efficiency for solar cells based on multiphoton processes in these materials.

Wang, Weiming; Lin, Albert S.; Phillips, Jamie D.; Metzger, Wyatt K.

2009-01-01T23:59:59.000Z

422

Polariton lasing in a ZnO microwire above 450?K  

SciTech Connect (OSTI)

Exciton-polariton lasing in a one-dimensional ZnO microcavity is demonstrated at high temperature of 455?K. The massive occupation of the polariton ground state above a distinct pump power threshold is clearly demonstrated by using the angular resolved spectroscopy under non-resonant excitation. The temperature dependence of the polariton lasing threshold is well interpreted by two competing mechanisms, i.e., the thermodynamic and kinetic mechanisms. Michelson interference measurements are performed to investigate the temporal and spatial coherence of polariton laser, with the coherence time and coherence length being ?{sub c}?0.97?ps and r{sub c}?0.72?m at 440?K and 400?K, respectively.

Xu, Dan; Xie, Wei; Liu, Wenhui; Wang, Jian; Zhang, Long; Wang, Yinglei; Zhang, Saifeng; Sun, Liaoxin; Shen, Xuechu; Chen, Zhanghai, E-mail: zhanghai@fudan.edu.cn [State Key Laboratory of Surface Physics, Department of Physics and Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (China)

2014-02-24T23:59:59.000Z

423

Hydrogen passivation of electron trap in amorphous In-Ga-Zn-O thin-film transistors  

SciTech Connect (OSTI)

We report an experimental evidence that some hydrogens passivate electron traps in an amorphous oxide semiconductor, a-In-Ga-Zn-O (a-IGZO). The a-IGZO thin-film transistors (TFTs) annealed at 300?C exhibit good operation characteristics; while those annealed at ?400?C show deteriorated ones. Thermal desorption spectra (TDS) of H{sub 2}O indicate that this threshold annealing temperature corresponds to depletion of H{sub 2}O desorption from the a-IGZO layer. Hydrogen re-doping by wet oxygen annealing recovers the good TFT characteristic. The hydrogens responsible for this passivation have specific binding energies corresponding to the desorption temperatures of 300430?C. A plausible structural model is suggested.

Hanyu, Yuichiro, E-mail: y-hanyu@lucid.msl.titech.ac.jp; Domen, Kay [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan)] [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Nomura, Kenji [Frontier Research Center, Tokyo Institute of Technology, Yokohama (Japan)] [Frontier Research Center, Tokyo Institute of Technology, Yokohama (Japan); Hiramatsu, Hidenori; Kamiya, Toshio [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan) [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama (Japan); Kumomi, Hideya [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama (Japan)] [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama (Japan); Hosono, Hideo [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan) [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Frontier Research Center, Tokyo Institute of Technology, Yokohama (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama (Japan)

2013-11-11T23:59:59.000Z

424

HRTEM and XPS study of nanoparticle formation in Zn{sup +} ion implanted Si  

SciTech Connect (OSTI)

The results of investigations of nanoparticles (NPs) formation in a near surface layer of Si substrate after {sup 64}Zn{sup +} ion implantation and thermal annealing are presented. The implantation energy and dose were correspondently E=100keV and D?=?210{sup 16} cm{sup ?2}. Than the samples were subsequently isochronously subjected to furnace annealing during 1h in neutral atmosphere at 400C and in oxygen atmosphere at 600, 700 and 800C. The visualization of near surface layer was carried out by transmission electron microscopy with addition of electron diffraction. The energy dispersive spectroscopy was used for value of impurity concentration. The charge state of implanted zinc, silicon matrix atom and oxygen and were carried out by X-ray photoelectron spectroscopy and Auger electron spectroscopy.

Privezentsev, Vladimir V. [Institute of Physics and Technology of the RAS, Nakhimovskiy prosp.34, 117218 Moscow (Russian Federation); Tabachkova, Natalya Yu. [National University of Science and Technology ''MISiS'', Leninskiy prosp. 4, 119049 Moscow (Russian Federation); Lebedinskii, Yurii Yu. [National Research Nuclear University ''MIPhI'', Kashirskoe sh. 31, 115409 Moscow (Russian Federation)

2014-02-21T23:59:59.000Z

425

Measurement of the $^{58}$Ni($?$,$?$)$^{62}$Zn reaction and its astrophysical impact  

E-Print Network [OSTI]

Cross section measurements of the $^{58}$Ni($\\alpha$,$\\gamma$)$^{62}$Zn reaction were performed in the energy range $E_{\\alpha}=5.5-9.5$ MeV at the Nuclear Science Laboratory of the University of Notre Dame, using the NSCL Summing NaI(Tl) detector and the $\\gamma$-summing technique. The measurements are compared to predictions in the statistical Hauser-Feshbach model of nuclear reactions using the SMARAGD code. It is found that the energy dependence of the cross section is reproduced well but the absolute value is overestimated by the prediction. This can be remedied by rescaling the $\\alpha$ width by a factor of 0.45. Stellar reactivities were calculated with the rescaled $\\alpha$ width and their impact on nucleosynthesis in type Ia supernovae has been studied. It is found that the resulting abundances change by up to 5\\% when using the new reactivities.

S. J. Quinn; A. Spyrou; E. Bravo; T. Rauscher; A. Simon; A. Battaglia; M. Bowers; B. Bucher; C. Casarella; M. Couder; P. A. DeYoung; A. C. Dombos; J. Grres; A. Kontos; Q. Li; A. Long; M. Moran; N. Paul; J. Pereira; D. Robertson; K. Smith; M. K. Smith; E. Stech; R. Talwar; W. P. Tan; M. Wiescher

2014-05-23T23:59:59.000Z

426

Effect of implanted species on thermal evolution of ion-induced defects in ZnO  

SciTech Connect (OSTI)

Implanted atoms can affect the evolution of ion-induced defects in radiation hard materials exhibiting a high dynamic annealing and these processes are poorly understood. Here, we study the thermal evolution of structural defects in wurtzite ZnO samples implanted at room temperature with a wide range of ion species (from {sup 11}B to {sup 209}Bi) to ion doses up to 2??10{sup 16}?cm{sup ?2}. The structural disorder was characterized by a combination of Rutherford backscattering spectrometry, nuclear reaction analysis, and transmission electron microscopy, while secondary ion mass spectrometry was used to monitor the behavior of both the implanted elements and residual impurities, such as Li. The results show that the damage formation and its thermal evolution strongly depend on the ion species. In particular, for F implanted samples, a strong out-diffusion of the implanted ions results in an efficient crystal recovery already at 600?C, while co-implantation with B (via BF{sub 2}) ions suppresses both the F out-diffusion and the lattice recovery at such low temperatures. The damage produced by heavy ions (such as Cd, Au, and Bi) exhibits a two-stage annealing behavior where efficient removal of point defects and small defect clusters occurs at temperatures ?500?C, while the second stage is characterized by a gradual and partial annealing of extended defects. These defects can persist even after treatment at 900?C. In contrast, the defects produced by light and medium mass ions (O, B, and Zn) exhibit a more gradual annealing with increasing temperature without distinct stages. In addition, effects of the implanted species may lead to a nontrivial defect evolution during the annealing, with N, Ag, and Er as prime examples. In general, the obtained results are interpreted in terms of formation of different dopant-defect complexes and their thermal stability.

Azarov, A. Yu.; Rauwel, P.; Kuznetsov, A. Yu.; Svensson, B. G. [Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo (Norway); Halln, A. [Royal Institute of Technology, KTH-ICT, Electrum 229, SE-164 40, Kista, Stockholm (Sweden); Du, X. L. [Institute of Physics, The Chinese Academy of Sciences, Beijing 100190 (China)

2014-02-21T23:59:59.000Z

427

Polarimetric performance of a Laue lens gamma-ray CdZnTe focal plane prototype  

SciTech Connect (OSTI)

A gamma-ray telescope mission concept [gamma ray imager (GRI)] based on Laue focusing techniques has been proposed in reply to the European Space Agency call for mission ideas within the framework of the next decade planning (Cosmic Vision 2015-2025). In order to optimize the design of a focal plane for this satellite mission, a CdZnTe detector prototype has been tested at the European Synchrotron Radiation Facility under an {approx}100% polarized gamma-ray beam. The spectroscopic, imaging, and timing performances were studied and in particular its potential as a polarimeter was evaluated. Polarization has been recognized as being a very important observational parameter in high energy astrophysics (>100 keV) and therefore this capability has been specifically included as part of the GRI mission proposal. The prototype detector tested was a 5 mm thick CdZnTe array with an 11x11 active pixel matrix (pixel area of 2.5x2.5 mm{sup 2}). The detector was irradiated by a monochromatic linearly polarized beam with a spot diameter of about 0.5 mm over the energy range between 150 and 750 keV. Polarimetric Q factors of 0.35 and double event relative detection efficiency of 20% were obtained. Further measurements were performed with a copper Laue monochromator crystal placed between the beam and the detector prototype. In this configuration we have demonstrated that a polarized beam does not change its polarization level and direction after undergoing a small angle (<1 deg.) Laue diffraction inside a crystal.

Curado da Silva, R. M. [Departmento de Fisica, Universidade de Coimbra, P-3000 Coimbra (Portugal); Center for Space Radiations, Univesite Catholique de Louvain (Belgium); Caroli, E.; Stephen, J. B.; Schiavone, F.; Donati, A.; Ventura, G. [Istituto di Astrofisica Spaziale e Fisica Cosmica-Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Pisa, A.; Auricchio, N.; Frontera, F. [Dipartimento di Fisica, Universita di Ferrara, Ferrara (Italy); Del Sordo, S. [Istituto di Astrofisica Spaziale e Fisica Cosmica-Palermo, Via Ugo La Malfa 153, 90146 Palermo (Italy); Honkimaeki, V. [European Synchrotron Radiation Facility, Grenoble (France); Trindade, A. M. F. [Departmento de Fisica, Universidade de Coimbra, P-3000 Coimbra (Portugal)

2008-10-15T23:59:59.000Z

428

Amorphous Zn?GeO? Nanoparticles as Anodes with High Reversible Capacity and Long Cycling Life for Li-ion Batteries  

SciTech Connect (OSTI)

Amorphous and crystalline Zn?GeO? nanoparticles were prepared and characterized as anode materials for Li-ion batteries. A higher reversible specific capacity of 1250 mAh/g after 500 cycles and excellent rate capability were obtained for amorphous Zn?GeO? nanoparticles, compared to that of crystalline Zn?GeO? nanoparticles. Small particle size, amorphous phase and incorporation of zinc and oxygen contribute synergetically to the improved performance by effectively mitigating the huge volume variations during lithiation and delithiation process.

Yi, Ran; Feng, Jinkui; Lv, Dongping; Gordin, Mikhail; Chen, Shuru; Choi, Daiwon; Wang, Donghai

2013-07-30T23:59:59.000Z

429

Taheri-Saramad x-ray detector (TSXD): A novel high spatial resolution x-ray imager based on ZnO nano scintillator wires in polycarbonate membrane  

SciTech Connect (OSTI)

A novel x-ray imager based on ZnO nanowires is designed and fabricated. The proposed architecture is based on scintillation properties of ZnO nanostructures in a polycarbonate track-etched membrane. Because of higher refractive index of ZnO nanowire compared to the membrane, the nanowire acts as an optical fiber that prevents the generated optical photons to spread inside the detector. This effect improves the spatial resolution of the imager. The detection quantum efficiency and spatial resolution of the fabricated imager are 11% and <6.8 ?m, respectively.

Taheri, A., E-mail: at1361@aut.ac.ir; Saramad, S.; Ghalenoei, S.; Setayeshi, S. [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)] [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)

2014-01-15T23:59:59.000Z

430

Crystal structure and magnetic properties and Zn substitution effects on the spin-chain compound Sr{sub 3}Co{sub 2}O{sub 6}  

SciTech Connect (OSTI)

The effects of substituting Co on the spin-chain compound Sr{sub 3}Co{sub 2}O{sub 6} with Zn were investigated by synchrotron X-ray diffraction, magnetic susceptibility, isothermal magnetization, and specific heat measurements. To the best of our knowledge, this is the first report to describe the successful substitution of Co in Sr{sub 3}Co{sub 2}O{sub 6} with Zn. The substitution was carried out by a method involving high pressures and temperatures to obtain Sr{sub 3}CoZnO{sub 6}, which crystalized into a K{sub 4}CdCl{sub 6}-derived rhombohedral structure with a space group of R-3c, similar to the host compound. With the Zn substitution, the Ising-type magnetic anisotropy of the host compound remarkably reduced; the newly formed Sr{sub 3}CoZnO{sub 6} became magnetically isotropic with Heisenberg-type characteristics. This could probably be ascribed to the establishment of a different interaction pathway, Co{sup 4+}(S=1/2)OZn{sup 2+}(S=0)OCo{sup 4+}(S=1/2). Details of the magnetic properties of Zn substituted Sr{sub 3}Co{sub 2}O{sub 6} were reported. - Graphical abstract: Crystal structure of the spin-chain compound Sr{sub 3}CoZnO{sub 6} synthesized at 6 GPa. Zn atoms preferably occupy the trigonal prism sites rather than the octahedral sites. As a result, the compound is much magnetically isotropic. Highlights: Effects of substituting Co with Zn on spin-chain magnetism of Sr{sub 3}Co{sub 2}O{sub 6} were studied. High-pressure synthesis resulted in a solid solution of Sr{sub 3}CoZnO{sub 6}. Sr{sub 3}CoZnO{sub 6} showed more isotropic magnetism than the host Sr{sub 3}Co{sub 2}O{sub 6}.

Wang, Xia [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Guo, Yanfeng, E-mail: Yangfeng.Guo@physics.ox.ac.uk [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Sun, Ying [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [Materials Processing Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba Ibaraki 305-0047 (Japan); Matsushita, Yoshitaka [Materials Analysis Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba Ibaraki 305-0047 (Japan); Yamaura, Kazunari, E-mail: yamaura.kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan)

2013-08-15T23:59:59.000Z

431

Room-temperature photomagnetism in the spinel ferrite (Mn,Zn,Fe)3O4 as seen via soft x-ray magnetic circular dichroism  

E-Print Network [OSTI]

photomagnetism in the spinel ferrite (Mn,Zn,Fe)3O4 as seendoped garnets 1 , doped spinel ferrites 2 , doped perovskiteIn the doped garnets and ferrites, the microscopic origin of

Bettinger, J.S.

2010-01-01T23:59:59.000Z

432

Final results of an experiment to search for 2beta processes in zinc and tungsten with the help of radiopure ZnWO4 crystal scintillators  

E-Print Network [OSTI]

A search for the double beta decay of zinc and tungsten isotopes has been performed with the help of radiopure ZnWO4 crystal scintillators (0.1-0.7 kg) at the Gran Sasso National Laboratories of the INFN. The total exposure of the low background measurements is 0.529 kg yr. New improved half-life limits on the double beta decay modes of 64Zn, 70Zn, 180W, and 186W have been established at the level of 10^{18}-10^{21} yr. In particular, limits on double electron capture and electron capture with positron emission in 64Zn have been set: T_{1/2}(2\

P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; S. d'Angelo; A. Incicchitti; V. V. Kobychev; D. V. Poda; V. I. Tretyak

2011-10-18T23:59:59.000Z

433

Fabrication of the ZnO thin films using wet-chemical etching processes on application for organic light emitting diode (OLED) devices  

E-Print Network [OSTI]

- sively used in solar cells, touch panels, heat mirrors, organic electro- luminescence devices (OLED- chemical etching behaviors of ZnO films were also investigated using various chemicals. In order

Hong, Byungyou

434

Optical Properties of Zn(O,S) Thin Films Deposited by RF Sputtering, Atomic Layer Deposition, and Chemical Bath Deposition: Preprint  

SciTech Connect (OSTI)

Zn(O,S) thin films 27 - 100 nm thick were deposited on glass or Cu(InxGa1-x)Se2/Molybdenum/glass with RF sputtering, atomic layer deposition, and chemical bath deposition.

Li, J.; Glynn, S.; Christensen, S.; Mann, J.; To, B.; Ramanathan, K.; Noufi, R.; Furtak, T. E.; Levi, D.

2012-06-01T23:59:59.000Z

435

Bicolor Mn-doped CuInS{sub 2}/ZnS core/shell nanocrystals for white light-emitting diode with high color rendering index  

SciTech Connect (OSTI)

We synthesized bicolor Mn-doped CuInS{sub 2} (CIS)/ZnS core/shell nanocrystals (NCs), in which Mn{sup 2+} ions and the CIS core were separated with a ZnS layer, and both Mn{sup 2+} ions and CIS cores could emit simultaneously. Transmission electron microscopy and powder X-ray diffraction measurements indicated the epitaxial growth of ZnS shell on the CuInS{sub 2} core, and electron paramagnetic resonance spectrum indicated that Mn{sup 2+} ions were on the lattice points of ZnS shell. By integrating these bicolor NCs with commercial InGaN-based blue-emitting diodes, tricolor white light-emitting diodes with color rendering index of 83 were obtained.

Huang, Bo; Dai, Qian; Zhang, Huichao; Liao, Chen; Cui, Yiping; Zhang, Jiayu, E-mail: jyzhang@seu.edu.cn [Advanced Photonic Center, Southeast University, Nanjing 210096 (China); Zhuo, Ningze; Jiang, Qingsong; Shi, Fenghua; Wang, Haibo [Research Institute of Electric Light Source Materials, Nanjing University of Technology, Nanjing 210015 (China)

2014-09-07T23:59:59.000Z

436

Determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer quantum dots via spectral analysis of optical signature of the Aharanov-Bohm excitons  

SciTech Connect (OSTI)

For submonolayer quantum dot (QD) based photonic devices, size and density of QDs are critical parameters, the probing of which requires indirect methods. We report the determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer QDs, based on spectral analysis of the optical signature of Aharanov-Bohm (AB) excitons, complemented by photoluminescence studies, secondary-ion mass spectroscopy, and numerical calculations. Numerical calculations are employed to determine the AB transition magnetic field as a function of the type-II QD radius. The study of four samples grown with different tellurium fluxes shows that the lateral size of QDs increases by just 50%, even though tellurium concentration increases 25-fold. Detailed spectral analysis of the emission of the AB exciton shows that the QD radii take on only certain values due to vertical correlation and the stacked nature of the QDs.

Ji, Haojie; Dhomkar, Siddharth; Roy, Bidisha; Kuskovsky, Igor L. [Department of Physics, Queens College of CUNY, Queens, New York 11367 (United States); The Graduate Center of CUNY, New York, New York 10016 (United States); Shuvayev, Vladimir [Department of Physics, Queens College of CUNY, Queens, New York 11367 (United States); Deligiannakis, Vasilios; Tamargo, Maria C. [The Graduate Center of CUNY, New York, New York 10016 (United States); Department of Chemistry, City College of CUNY, New York, New York 10031 (United States); Ludwig, Jonathan [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States); Smirnov, Dmitry [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Wang, Alice [Evans Analytical Group, Sunnyvale, California 94086 (United States)

2014-10-28T23:59:59.000Z

437

Formation and characterization of microstructure of as-cast Mg6Gd4YxZn0.5Zr (x = 0.3, 0.5 and 0.7 wt.%) alloys  

SciTech Connect (OSTI)

Mg6Gd4YxZn0.5Zr (x = 0.3, 0.5 and 0.7 wt.%) alloys were prepared via conventional ingot metallurgy (I/M) in this study. The as-cast microstructures of these alloys were established by X-ray diffraction (XRD) analyses, optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM) observations. Lamellar stacking order (SF) and 14H-type long period stacking order (LPSO) structure within ?-Mg matrix are formed in the three as-cast alloys. The eutectic secondary phase is (Mg,Zn){sub 24}(Gd,Y){sub 5} for the alloy containing 0.3 wt.% Zn, while, it is (Mg,Zn){sub 3}(Gd,Y) for the alloys containing 0.5 wt.% Zn and 0.7 wt.% Zn. Moreover, X phase-(Mg,Zn){sub 12}(Gd,Y) is formed in the latter two as-cast alloys. - Highlights: LPSO structure has first been found in as-cast Mg6Gd4YxZn0.5Zr. X-phase exists in as-cast Mg6Gd4Y0.3(0.5)Zn0.5Zr. Zn content results in different ?-phase in the studied alloys.

Wu, Y.J. [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Xu, C. [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240 (China); Zheng, F.Y. [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Peng, L.M., E-mail: plm616@sjtu.edu.cn [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Y.; Ding, W.J. [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)

2013-05-15T23:59:59.000Z

438

Recombination luminescence and trap levels in undoped and Al-doped ZnO thin films on quartz and GaSe (0 0 0 1) substrates  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer ZnO films on GaSe create electron trapping states and PL recombination levels. Black-Right-Pointing-Pointer Zn and Al diffusion in GaSe produces low-energy widening of its PL emission. Black-Right-Pointing-Pointer ZnO:Al films on GaSe lamellas are suitable for gas-discharge lamp applications. -- Abstract: Photoluminescence spectra of ZnO and ZnO:Al (1.00, 2.00 and 5.00 at.%) films on GaSe (0 0 0 1) lamellas and amorphous quartz substrates, obtained by annealing, at 700 K, of undoped and Al-doped metal films, are investigated. For all samples, the nonequilibrium charge carriers recombine by radiative band-to-band transitions with energy of 3.27 eV, via recombination levels created by the monoionized oxygen atoms, forming the impurity band laying in the region 2.00 - 2.70 eV. Al doping induces an additional recombination level at 1.13 eV above the top of the valence band of ZnO films on GaSe substrates. As a result of thermal diffusion of Zn and Al into the GaSe interface layer from ZnO:Al/GaSe heterojunction, electron trap levels located at 0.22 eV and 0.26 eV below the conduction band edge of GaSe, as well as a deep recombination level, responsible for the luminescent emission in the region 1.10 - 1.40 eV, are created.

Evtodiev, I. [Moldova State University, 60 A. Mateevici Str., Chisinau, MD 2009, Republic of Moldova (Moldova, Republic of)] [Moldova State University, 60 A. Mateevici Str., Chisinau, MD 2009, Republic of Moldova (Moldova, Republic of); Caraman, I. [Vasile Alecsandri University of Bacau, 157 Calea Marasesti, RO 600115 Bacau (Romania)] [Vasile Alecsandri University of Bacau, 157 Calea Marasesti, RO 600115 Bacau (Romania); Leontie, L., E-mail: lleontie@uaic.ro [Alexandru Ioan Cuza University of Iasi, Bd. Carol I, Nr. 11, RO 700506 Iasi (Romania); Rusu, D.-I. [Vasile Alecsandri University of Bacau, 157 Calea Marasesti, RO 600115 Bacau (Romania)] [Vasile Alecsandri University of Bacau, 157 Calea Marasesti, RO 600115 Bacau (Romania); Dafinei, A. [Faculty of Physics, University of Bucharest, Platforma Magurele, Str. Fizicienilor nr. 1, CP Mg - 11, Bucharest-Magurele, RO 76900 (Romania)] [Faculty of Physics, University of Bucharest, Platforma Magurele, Str. Fizicienilor nr. 1, CP Mg - 11, Bucharest-Magurele, RO 76900 (Romania); Nedeff, V.; Lazar, G. [Vasile Alecsandri University of Bacau, 157 Calea Marasesti, RO 600115 Bacau (Romania)] [Vasile Alecsandri University of Bacau, 157 Calea Marasesti, RO 600115 Bacau (Romania)

2012-03-15T23:59:59.000Z

439

Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells  

E-Print Network [OSTI]

1 Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells, Setagaya-ku, Tokyo 157-8572, Japan (Received ) KEYWORDS: ZnS buffer, Cu(In,Ga)Se2, thin-film solar cells alternative to CdS in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency

Sites, James R.

440

Schottky barrier source-gated ZnO thin film transistors by low temperature atomic layer deposition  

SciTech Connect (OSTI)

We have fabricated ZnO source-gated thin film transistors (SGTFTs) with a buried TiW source Schottky barrier and a top gate contact. The ZnO active channel and thin high-? HfO{sub 2} dielectric utilized are both grown by atomic layer deposition at temperatures less than 130?C, and their material and electronic properties are characterized. These SGTFTs demonstrate enhancement-mode operation with a threshold voltage of 0.91?V, electron mobility of 3.9 cm{sup 2} V{sup ?1} s{sup ?1}, and low subthreshold swing of 192?mV/decade. The devices also exhibit a unique combination of high breakdown voltages (>20?V) with low output conductances.

Ma, Alex M.; Gupta, Manisha; Shoute, Gem; Tsui, Ying Y.; Barlage, Douglas W., E-mail: barlage@ualberta.ca [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Afshar, Amir; Cadien, Kenneth C. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)] [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)

2013-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Near-resonant second-order nonlinear susceptibility in c-axis oriented ZnO nanorods  

SciTech Connect (OSTI)

Near-resonant second-harmonic generation (SHG) in c-axis oriented ZnO nanorods is studied under the femtosecond laser with wavelength from 780?nm to 810?nm. A highly efficient SHG is obtained, which is attributed to the d{sub 131} component of the second-order nonlinear susceptibility. The largest d{sub 131} value is estimated to be 10.2?pm/V at the pumping wavelength of 800?nm, which indicates a large SHG response of the c-axis oriented ZnO nanorods in the near-resonant region. Theoretical calculation based on finite-difference time-domain simulation suggests a four-fold local-field enhancement of the SHG.

Liu, Weiwei; Wang, Kai; Long, Hua; Wang, Bing, E-mail: wangbing@hust.edu.cn; Lu, Peixiang, E-mail: lupeixiang@hust.edu.cn [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Chu, Sheng [School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

2014-08-18T23:59:59.000Z

442

Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis  

SciTech Connect (OSTI)

Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental evidence from bulk-, surface-sensitive and imaging methods collected on real high-performance catalytic systems in combination with DFT calculations. We show that the active site consists of Cu steps peppered with Zn atoms, all stabilized by a series of well defined bulk defects and surface species that need jointly to be present for the system to work.

Behrens, Malte

2012-03-28T23:59:59.000Z

443

Tailoring the coercivity in ferromagnetic ZnO thin films by 3d and 4f elements codoping  

SciTech Connect (OSTI)

Cluster free, Co (3d) and Eu (4f) doped ZnO thin films were prepared using ion implantation technique accompanied by post annealing treatments. Compared with the mono-doped ZnO thin films, the samples codoped with Co and Eu exhibit a stronger magnetization with a giant coercivity of 1200?Oe at ambient temperature. This was further verified through x-ray magnetic circular dichroism analysis, revealing the exchange interaction between the Co 3d electrons and the localized carriers induced by Eu{sup 3+} ions codoping. The insight gained with modulating coercivity in magnetic oxides opens up an avenue for applications requiring non-volatility in spintronic devices.

Lee, J. J.; Xing, G. Z., E-mail: guozhong.xing@unsw.edu.au; Yi, J. B.; Li, S. [School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales 2052 (Australia)] [School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales 2052 (Australia); Chen, T. [Department of Physics, The Chinese University of Hong Kong, Shatin (Hong Kong)] [Department of Physics, The Chinese University of Hong Kong, Shatin (Hong Kong); Ionescu, M. [Australian Nuclear Science and Technology Organization, Sydney, New South Wales 2234 (Australia)] [Australian Nuclear Science and Technology Organization, Sydney, New South Wales 2234 (Australia)

2014-01-06T23:59:59.000Z

444

Fusion Cross Section in the {sup 4,6}He+{sup 64}Zn Collisions Around the Coulomb Barrier  

SciTech Connect (OSTI)

New fusion data for the {sup 4}He+{sup 64}Zn system at sub-barrier energies are measured to cover the same energy region of previous measurements for {sup 6}He+{sup 64}Zn. Aim of the experiment was to compare the fusion excitation functions for the two system to investigate on the effects of the {sup 6}He neutron-halo structure on the fusion reaction mechanism at energies around the Coulomb barrier. The fusion cross section was measured by using an activation technique. Comparing the two systems, we observe an enhancement of the fusion cross section in the reaction induced by {sup 6}He, at and below the Coulomb barrier.

Fisichella, M. [Dipartimento di Fisica, Universita di Messina, Messina (Italy); INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy); Di Pietro, A.; Figuera, P.; Marchetta, C. [INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy); Lattuada, M.; Musumarra, A.; Pellegriti, M. G.; Scuderi, V.; Strano, E.; Torresi, D. [INFN-Laboratori Nazionali del Sud and sezione di Catania, Catania (Italy); Dipartimento di Fisica ed Astronomia, Universita di Catania, Catania (Italy); Milin, M. [Department of Physics Faculty of Science University of Zagreb, Zagreb (Croatia); Skukan, N.; Zadro, M. [Ruder Boskovic Institute, Zagreb (Croatia)

2011-10-28T23:59:59.000Z

445

Indication of Te segregation in laser-irradiated ZnTe observed by in situ coherent-phonon spectroscopy  

SciTech Connect (OSTI)

We irradiate a ZnTe single crystal with 10-fs laser pulses at a repetition rate of 80?MHz and investigate its resulting gradual modification by means of coherent-phonon spectroscopy. We observe the emergence of a phonon mode at about 3.6?THz whose amplitude and lifetime grow monotonously with irradiation time. The speed of this process depends sensitively on the pump-pulse duration. Our observations strongly indicate that the emerging phonon mode arises from a Te phase induced by multiphoton absorption of incident laser pulses. A potential application of our findings is laser-machining of microstructures in the bulk of a ZnTe crystal, a highly relevant electrooptic material.

Shimada, Toru [Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Hirosaki University, 1 Bunkyo-cho, Hirosaki, Aomori 036-8152 (Japan); Kamaraju, N., E-mail: nkamaraju@lanl.gov [Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Los Alamos National Laboratory, Center for Integrated Nanotechnologies, Los Alamos, New Mexico 87545 (United States); Frischkorn, Christian [Department of Physics, Free University of Berlin, Arnimallee 14, 14195 Berlin (Germany); Wolf, Martin; Kampfrath, Tobias [Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany)

2014-09-15T23:59:59.000Z

446

Structure and red shift of optical band gap in CdOZnO nanocomposite synthesized by the sol gel method  

SciTech Connect (OSTI)

The structure and the optical band gap of CdOZnO nanocomposites were studied. Characterization using X-ray diffraction (XRD), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS) analysis confirms that CdO phase is present in the nanocomposites. TEM analysis confirms the formation of spheroidal nanoparticles and nanorods. The particle size was calculated from DebeySherrer?s formula and corroborated by TEM images. FTIR spectroscopy shows residual organic materials (aromatic/Olefinic carbon) from nanocomposites surface. CdO content was modified in the nanocomposites in function of polyvinylalcohol (PVA) added. The optical band gap is found to be red shift from 3.21 eV to 3.11 eV with the increase of CdO content. Photoluminescence (PL) measurements reveal the existence of defects in the synthesized CdOZnO nanocomposites. - Graphical abstract: Optical properties of ZnO, CdO and ZnO/CdO nanoparticles. Display Omitted - Highlights: TEM analysis confirms the presence of spherical nanoparticles and nanorods. The CdO phase is present in the nanocomposites. The band gap of the CdOZnO nanocomposites is slightly red shift with CdO content. PL emission of CdOZnO nanocomposite are associated to structural defects.

Mosquera, Edgar, E-mail: edemova@ing.uchile.cl [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Fsicas y Matemticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile); Pozo, Ignacio del, E-mail: ignacio.dpf@gmail.com [Facultad de Ciencias Naturales, Matemticas y del Medio Ambiente, Universidad Tecnolgica Metropolitana, Av. Jos Pedro Alessandri 1242, Santiago (Chile); Morel, Mauricio, E-mail: mmorel@ing.uchile.cl [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Fsicas y Matemticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile)

2013-10-15T23:59:59.000Z

447

Structural, compositional, and photoluminescence characterization of thermal chemical vapor deposition-grown Zn{sub 3}N{sub 2} microtips  

SciTech Connect (OSTI)

The catalytic growth of Zn{sub 3}N{sub 2} using guided-stream thermal chemical vapor deposition has been investigated within the parameter range of acicular growth to obtain uniform microtips with a high crystalline quality. The cubic anti-bixbyite crystal structure of Zn{sub 3}N{sub 2} microtips and its related phonon mode are revealed by X-ray diffraction and Raman spectroscopy, respectively. The surface morphologies of pure and surface-oxidized Zn{sub 3}N{sub 2} microtips are depicted by scanning electron microscopy and show the crack formation on the surface-oxidized Zn{sub 3}N{sub 2} microtips. The spatial element distribution map confirms the VLS growth mechanism for Zn{sub 3}N{sub 2} microtips and reveals the depth profile of zinc, nitrogen, oxygen, and nickel elements. Photoluminescence (PL) spectra of Zn{sub 3}N{sub 2} microtips show a sharp infrared band-to-band emission peak at 1.34?eV with a full width at half maximum of ?100?meV and a very broad oxygen-related defect band emission peak centered at ?0.85?eV.

Wei, Pai-Chun, E-mail: pcwei68@gmail.com, E-mail: tsengcm@phys.sinica.edu.tw; Chang, Chung-Chieh; Hsu, Chia-Hao [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Tong, Shih-Chang; Shen, Ji-Lin [Department of Physics, Chung Yuan Christian University, Chung-Li 32023, Taiwan (China); Tseng, Chuan-Ming, E-mail: pcwei68@gmail.com, E-mail: tsengcm@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Institute of Materials Science and Engineering, National Central University, Tao-Yuan 32001, Taiwan (China)

2014-10-14T23:59:59.000Z

448

Interface structure and anisotropic strain relaxation of nonpolar wurtzite (1120) and (1010) orientations: ZnO epilayers grown on sapphire  

SciTech Connect (OSTI)

The interface properties between nonpolar ZnO and sapphire have been studied using high resolution transmission electron microscopy. Two nonpolar orientations are investigated: a- and m-orientations corresponding to [1120] and [1010] crystallographic directions. After the definition of the epitaxial relationships and the resulting initial lattice mismatch, we show that nonpolar ZnO can be grown on sapphire with perfectly flat interfaces. Geometrical misfit dislocations are observed at the interface ZnO/sapphire and their density gives the residual strain in the layer. A strong anisotropy in the strain relaxation is found along the two perpendicular in-plane directions. This anisotropy may be explained in terms of initial anisotropic mismatch yielding different relaxation processes. A domain matching epitaxy is observed in m- and a-oriented layers for mismatches larger than 9% while a lattice matching epitaxy, in which the relaxation is driven by nucleation and glide of dislocations, is observed in a-oriented ZnO along the [0001] in-plane direction. In order to explain the observed relaxation the activated slip systems are calculated for both nonpolar orientations as a function of the in-plane stress due to the anisotropic mismatch. There is a major difference from the polar orientations. Low energy prismatic slip systems can be effective for plastic relaxation in the nonpolar orientations because they are no longer parallel to the growth direction, which is the case of c-oriented layers, nor to the applied stress. Our results can be directly extended to other nonpolar wurtzite structures such as III-nitrides.

Chauveau, J.-M. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France); Physics Department, University of Nice Sophia Antipolis, Parc Valrose, F-06102 Nice Cedex 2 (France); Vennegues, P.; Lauegt, M.; Deparis, C.; Zuniga-Perez, J.; Morhain, C. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, Centre National de la Recherche Scientifique (CRHEA-CNRS), Rue B. Gregory, F-06560 Valbonne Sophia Antipolis (France)

2008-10-01T23:59:59.000Z

449

Structural and magnetic properties of NiZn-ferrite thin films prepared by radio frequency magnetron sputtering  

SciTech Connect (OSTI)

Polycrystalline NiZn-ferrite thin films were deposited on Si(100) substrate by rf magnetron sputtering, using targets with a nominal composition of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}. The effects of substrate condition, sputtering pressure, and postannealing on the structure and magnetic properties of thin films have been investigated. Our results show that the preferred orientation of the NiZn spinel film changed from (311) to (400) with increasing the Ar pressure from 0.8 to 1.6 Pa, meanwhile, the grain size also increased. Atomic force microscopy analysis indicates that perfect surface morphology of the film can be obtained at a relatively lower sputtering pressure of 1.0 Pa. The relative percentage of residual oxygen increases significantly on a condition of lower sputtering pressure, and plays an important role in film structure due to the strong molecular adsorption tendency of oxygen on the film surface during the deposition process. A thin film with a typical thickness of 1 {mu}m, a saturation magnetization of 150 emu/cm{sup 3}, and a coercivity of 8.8 kA/m has been obtained after annealing at 800 deg. C, which has the potential application in magnetic integrated circuits.

Liu Yingli; Li Yuanxun; Zhang Huaiwu; Chen Daming; Mu Chunhong [State Key Laboratory of Electronic Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2011-04-01T23:59:59.000Z

450

Magnetic resonance investigation of Zn{sub 1?x}Fe{sub x}O properties influenced by annealing atmosphere  

SciTech Connect (OSTI)

ZnO is an attractive system for a wide variety of practical applications, being a chemically stable oxide semiconductor. It has been shown that Fe doping produces ferromagnetic semiconductor at room temperature. This material, therefore, has the potential for use in spintronic devices such as spin transistors, spin light emitting diodes, very high density nonvolatile semiconductor memory and optical emitters. It is believed that oxygen vacancies and substitutional incorporation are important to produce ferromagnetism in semiconductor oxide doped with transition metal ions. The present paper reports detailed electron paramagnetic resonance investigations (EPR) of the samples in order to investigate how annealing atmosphere (Air and Argon) influenced the magnetic behavior of the samples. X-band electron paramagnetic resonance (EPR) studies of Fe{sup 3+} ions in Zn{sub 1?x}Fe{sub x}O powders with x = 1%, 3% is reported. These samples are interesting to investigate as Fe doping produce ferromagnetism in ZnO, making a promising ferromagnetic semiconductor at room temperature.

Raita, O.; Popa, A.; Toloman, D.; Stan, M.; Giurgiu, L. M. [National Institute for Research and Development of Isotopic and Molecular Technologies Donath 65-103, 400293, Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies Donath 65-103, 400293, Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

451

Luminescence and electrical properties of solution-processed ZnO thin films by adding fluorides and annealing atmosphere  

SciTech Connect (OSTI)

Highlights: {yields} Systematic study of the fluorides doped solution-processed ZnO thin films via the luminescence and electrical behaviors. {yields} Defect-related visible emission bands are affected by annealing ambient and fluoride addition. {yields} Adding lithium fluoride followed by annealing in oxygen ambient leads to a controlled defect density with proper TFT performance. -- Abstract: To develop an efficient channel layer for thin film transistors (TFTs), understanding the defect-related luminescence and electrical property is crucial for solution-processed ZnO thin films. Film growth with the fluorides addition, especially using LiF, followed by the oxygen ambient post-annealing leads to decreased defect-related emission as well as enhanced switching property. The saturation mobility and current on/off ratio are 0.31 cm{sup 2} V{sup -1} s{sup -1} and 1.04 x 10{sup 3}. Consequently, we can visualize an optimized process condition and characterization method for solution-processed TFT based on the fluorine-doped ZnO film channel layer by considering the overall emission behavior.

Choi, Sungho, E-mail: shochoi@krict.re.kr [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of); Park, Byung-Yoon [Chemical and Electronic Materials Division, LG Electronics, Hyangjeong-dong, Heungdeok-gu, Cheongju (Korea, Republic of)] [Chemical and Electronic Materials Division, LG Electronics, Hyangjeong-dong, Heungdeok-gu, Cheongju (Korea, Republic of); Jung, Ha-Kyun [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of)

2011-06-15T23:59:59.000Z

452

ZnO:Al Doping Level and Hydrogen Growth Ambient Effects on CIGS Solar Cell Performance: Preprint  

SciTech Connect (OSTI)

Cu(In,Ga)Se2 (CIGS) photovoltaic (PV) cells require a highly conducting and transparent electrode for optimum device performance. ZnO:Al films grown from targets containing 2.0 wt.% Al2O3 are commonly used for this purpose. Maximum carrier mobilities of these films grown at room temperature are ~20-25 cm2V-1s-1. Therefore, relatively high carrier concentrations are required to achieve the desired conductivity, which leads to free carrier absorption in the near infrared (IR). Lightly doped films (0.05 - 0.2 wt.% Al2O3), which show less IR absorption, reach mobility values greater than 50 cm2V-1s-1 when deposited in H2 partial pressure. We incorporate these lightly doped ZnO:Al layers into CIGS PV cells produced at the National Renewable Energy Laboratory (NREL). Preliminary results show quantum efficiency values of these cells rival those of a past world-record cell produced at NREL that used 2.0 wt.% Al-doped ZnO films. The highest cell efficiency obtained in this trial was 18.1%.

Duenow, J. N.; Gessert, T. A.; Wood, D. M.; Egaas, B.; Noufi, R.; Coutts,T. J.

2008-05-01T23:59:59.000Z

453

Photo-modulated thin film transistor based on dynamic charge transfer within quantum-dots-InGaZnO interface  

SciTech Connect (OSTI)

The temporal development of next-generation photo-induced transistor across semiconductor quantum dots and Zn-related oxide thin film is reported in this paper. Through the dynamic charge transfer in the interface between these two key components, the responsibility of photocurrent can be amplified for scales of times (?10{sup 4}?A/W 450?nm) by the electron injection from excited quantum dots to InGaZnO thin film. And this photo-transistor has a broader waveband (from ultraviolet to visible light) optical sensitivity compared with other Zn-related oxide photoelectric device. Moreover, persistent photoconductivity effect can be diminished in visible waveband which lead to a significant improvement in the device's relaxation time from visible illuminated to dark state due to the ultrafast quenching of quantum dots. With other inherent properties such as integrated circuit compatible, low off-state current and high external quantum efficiency resolution, it has a great potential in the photoelectric device application, such as photodetector, phototransistor, and sensor array.

Liu, Xiang [Electronic Science and Engineering School, Southeast University, Nanjing (China); National Center for Nanoscience and Technology, Beijing (China); Yang, Xiaoxia; Liu, Mingju [National Center for Nanoscience and Technology, Beijing (China); Tao, Zhi; Wei, Lei, E-mail: lw@seu.edu.cn; Li, Chi, E-mail: lichi@seu.edu.cn; Zhang, Xiaobing; Wang, Baoping [Electronic Science and Engineering School, Southeast University, Nanjing (China); Dai, Qing, E-mail: daiq@nanoctr.cn [National Center for Nanoscience and Technology, Beijing (China); London Center for Nanotechnology, University College London, London WC1H 0AH (United Kingdom); Nathan, Arokia [Electronic Science and Engineering School, Southeast University, Nanjing (China); London Center for Nanotechnology, University College London, London WC1H 0AH (United Kingdom)

2014-03-17T23:59:59.000Z

454

Investigation of combinatorial coevaporated thin film Cu{sub 2}ZnSnS{sub 4}. I. Temperature effect, crystalline phases, morphology, and photoluminescence  

SciTech Connect (OSTI)

Cu{sub 2}ZnSnS{sub 4} is a promising low-cost, nontoxic, earth-abundant absorber material for thin-film solar cell applications. In this study, combinatorial coevaporation was used to synthesize individual thin-film samples spanning a wide range of compositions at low (325?C) and high (475?C) temperatures. Film composition, grain morphology, crystalline-phase and photo-excitation information have been characterized by x-ray fluorescence, scanning electron microscopy, x-ray diffraction, Raman spectroscopy, and photoluminescence imaging and mapping. Highly textured columnar grain morphology is observed for film compositions along the ZnS-Cu{sub 2}ZnSnS{sub 4}-Cu{sub 2}SnS{sub 3} tie line in the quasi-ternary Cu{sub 2}S-ZnS-SnS{sub 2} phase system, and this effect is attributed to structural similarity between the Cu{sub 2}ZnSnS{sub 4}, Cu{sub 2}SnS{sub 3}, and ZnS crystalline phases. At 475?C growth temperature, Sn-S phases cannot condense because of their high vapor pressures. As a result, regions that received excess Sn flux during growth produced compositions falling along the ZnS-Cu{sub 2}ZnSnS{sub 4}-Cu{sub 2}SnS{sub 3} tie line. Room-temperature photoluminescence imaging reveals a strong correlation for these samples between film composition and photoluminescence intensity, where film regions with Cu/Sn ratios greater than ?2 show strong photoluminescence intensity, in comparison with much weaker photoluminescence in regions that received excess Sn flux during growth or subsequent processing. The observed photoluminescence quenching in regions that received excess Sn flux is attributed to the effects of Sn-related native point defects in Cu{sub 2}ZnSnS{sub 4} on non-radiative recombination processes. Implications for processing and performance of Cu{sub 2}ZnSnS{sub 4} solar cells are discussed.

Du, Hui; Yan, Fei; Young, Matthew; To, Bobby; Jiang, Chun-Sheng; Dippo, Pat; Kuciauskas, Darius; Teeter, Glenn, E-mail: glenn.teeter@nrel.gov [National Renewable Energy Laboratory, 15013 Denver West Parkway, MS3218, Golden, Colorado 80401 (United States); Chi, Zhenhuan [Renishaw Incorporated, 5277 Trillium Blvd., Hoffman Estates, Illinois 60192 (United States); Lund, Elizabeth A.; Hancock, Chris; Hlaing OO, Win Maw; Scarpulla, Mike A. [Departments of Chemical Engineering, Electrical and Computer Engineering, and Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)

2014-05-07T23:59:59.000Z

455

Electromagnetic properties of NiZn ferrite nanoparticles and their polymer composites  

SciTech Connect (OSTI)

The magnetic properties of polycrystalline NiZn ferrite nanoparticles synthesized using a polyol-reduction and coprecipitation reaction methods have been investigated. The effects on magnetization of synthesis approach, chemical composition, processing conditions, and on the size of nanoparticles on magnetization have been investigated. The measured room-temperature magnetization for the as-prepared magnetic nanoparticles (MNP) synthesized via polyol-reduction and coprecipitation is 69?Am{sup 2}?kg{sup ?1} and 14?Am{sup 2}?kg{sup ?1}, respectively. X-ray diffraction measurements confirm spinel structure of the particles with an estimated grain size of ?80?nm obtained from the polyol-reduction and 28?nm obtained from these coprecipitation techniques. Upon calcination under atmospheric conditions at different temperatures between 800?C and 1000?C, the magnetization, M, of the coprecipitated MNP increases to 76?Am{sup 2}?kg{sup ?1} with an estimated grain size of 90?nm. The MNP-polymer nanocomposites made from the synthesized MNP in various loading fraction and high density polyethylene exhibit interesting electromagnetic properties. The measured permeability and permittivity of the magnetic nanoparticle-polymer nanocomposites increases with the loading fractions of the magnetic nanoparticles, suggesting control for impedance matching for antenna applications.

Parsons, P. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Maryland 21005 (United States); Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Duncan, K. [U.S. Army, Communications-Electronics Research, Development and Engineering Center, Space and Terrestrial Communications Directorate, Aberdeen Proving Ground, Maryland 21005 (United States); Giri, A. K. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Maryland 21005 (United States); Bowhead Science and Technology, LLC, Belcamp, Maryland 21017 (United States); Xiao, J. Q. [Department of Physics and Astronomy, Universit