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We encourage you to perform a real-time search of NLEBeta
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1

Photothermal Response in Dual-Gated Bilayer Graphene M.-H. Kim,1  

E-Print Network [OSTI]

Photothermal Response in Dual-Gated Bilayer Graphene M.-H. Kim,1 J. Yan,1,2 R. J. Suess,3 T. E photoresponse in gapped bilayer graphene was investigated by optical and transport measurements. A pulse There is growing recognition that graphene has excep- tional potential as a new optoelectronic material, which has

Murphy, Thomas E.

2

Doping efficiency of single and randomly stacked bilayer graphene by iodine adsorption  

SciTech Connect (OSTI)

We report on the efficiency and thermal stability of p-doping by iodine on single and randomly stacked, weakly coupled bilayer polycrystalline graphene, as directly measured by photoelectron emission microscopy. The doping results in work function value increase of 0.4–0.5?eV, with a higher degree of iodine uptake by the bilayer (2%) as compared to the single layer (1%) suggesting iodine intercalation in the bilayer. The chemistry of iodine is identified accordingly as I{sub 3}{sup ?} and I{sub 5}{sup ?} poly iodide anionic complexes with slightly higher concentration of I{sub 5}{sup ?} in bilayer than monolayer graphene, likely attributed to differences in doping mechanisms. Temperature dependent in-situ annealing of the doped films demonstrated that the doping remains efficient up to 200?°C.

Kim, HoKwon; Renault, Olivier; Rouchon, Denis; Mariolle, Denis; Chevalier, Nicolas [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Tyurnina, Anastasia; Simonato, Jean-Pierre; Dijon, Jean [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LITEN, Minatec Campus, F-38054 Grenoble (France)

2014-07-07T23:59:59.000Z

3

High-Performance Integrated Dual-Gate AlGaN/GaN Enhancement-Mode Transistor  

E-Print Network [OSTI]

In this letter, we present a new AlGaN/GaN enhancement-mode (E-mode) transistor based on a dual-gate structure. The dual gate allows the transistor to combine an E-mode behavior with low on-resistance and very high breakdown ...

Lu, Bin

4

Optical Determination of Gate--Tunable Bandgap in Bilayer Graphene  

SciTech Connect (OSTI)

The electronic bandgap is an intrinsic property of semiconductors and insulators that largely determines their transport and optical properties. As such, it has a central role in modern device physics and technology and governs the operation of semiconductor devices such as p-n junctions, transistors, photodiodes and lasers. A tunable bandgap would be highly desirable because it would allow great flexibility in design and optimization of such devices, in particular if it could be tuned by applying a variable external electric field. However, in conventional materials, the bandgap is fixed by their crystalline structure, preventing such bandgap control. Here we demonstrate the realization of a widely tunable electronic bandgap in electrically gated bilayer graphene. Using a dual-gate bilayer graphene field-effect transistor (FET) and infrared microspectroscopy, we demonstrate a gate-controlled, continuously tunable bandgap of up to 250 meV. Our technique avoids uncontrolled chemical doping and provides direct evidence of a widely tunable bandgap -- spanning a spectral range from zero to mid-infrared -- that has eluded previous attempts. Combined with the remarkable electrical transport properties of such systems, this electrostatic bandgap control suggests novel nanoelectronic and nanophotonic device applications based on graphene.

Zhang, Yuanbo; Tang, Tsung-Ta; Girit, Caglar; Hao, Zhao; Martin, Michael C.; Zettl, Alex; Crommie, Michael F.; Shen, Y. Ron; Wang, Feng

2009-08-11T23:59:59.000Z

5

Bilayer Graphene Photon Detector J. Y. Yan, M.-H. Kim, J. A. Elle, A. B. Sushkov, G. S. Jenkins, H. M. Milchberg  

E-Print Network [OSTI]

Bilayer Graphene Photon Detector J. Y. Yan, M.-H. Kim, J. A. Elle, A. B. Sushkov, G. S. Jenkins, H in graphene suggests that "hot electrons" created by incident light can provide the basis for a fast graphene in a "dual-gated" structure. This new "bolometer" has ultralow noise, besting existing detectors

Shapiro, Benjamin

6

A strategy to stabilise the local structure of Ti{sup 4+} and Zn{sup 2+} species against aging in TiO{sub 2}/aluminium-doped ZnO bi-layers for applications in hybrid solar cells  

SciTech Connect (OSTI)

We explore a strategy to counteract aging issues in TiO{sub 2}/aluminium-doped ZnO bi-layers used in hybrid solar cells photo-anodes, mainly related to Zn diffusion in the TiO{sub 2} matrix. Different Ti{sup 4+} and Zn{sup 2+} local structures within the anatase grains and along the film thickness were found as a function of post-deposition annealing treatments in the range between 200?°C and 500?°C by synchrotron radiation extended x-ray absorption fine structure analyses. In particular, in the 500?°C-treated sample, diffusion of zinc species along the TiO{sub 2} grain-boundaries has been observed with aging (3?years). In contrast, a mild thermal budget at 200?°C favours a proper atomic arrangement of the zinc-containing anatase lattice which reduces Zn diffusion, thus guaranteeing a good stability with aging.

Pellegrino, Giovanna; La Magna, Antonino; Bongiorno, Corrado; Smecca, Emanuele; Alberti, Alessandra, E-mail: alessandra.alberti@imm.cnr.it [CNR-IMM Zona Industriale VIII Strada 5, 95121 Catania (Italy); Condorelli, Guglielmo G. [Università degli studi di Catania and INSTM UdR Catania V.le A. Doria 6, Catania (Italy); Mocuta, Cristian [Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP 48, 91192, Gif-sur-Yvette Cedex (France)

2014-08-07T23:59:59.000Z

7

Bilayer Graphene Gets a Bandgap  

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

Bilayer Graphene Gets a Bandgap Bilayer Graphene Gets a Bandgap Print Wednesday, 26 August 2009 00:00 Graphene is the two-dimensional crystalline form of carbon whose extraordinary...

8

Twist Solves Bilayer Graphene Mystery  

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

Twist Solves Bilayer Graphene Mystery Twist Solves Bilayer Graphene Mystery Print Wednesday, 26 March 2014 00:00 Researchers have discovered a unique new twist to the story of...

9

Cyclotron Resonance in Bilayer Graphene  

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

Resonance in Bilayer Graphene PI: Horst Stormer, Department of Physics, Columbia University Supported by NSF (DMR-03-52738 and CHE-0117752), ONR (N000150610138) DOE...

10

Lipid bilayers on nano-templates  

DOE Patents [OSTI]

A lipid bilayer on a nano-template comprising a nanotube or nanowire and a lipid bilayer around the nanotube or nanowire. One embodiment provides a method of fabricating a lipid bilayer on a nano-template comprising the steps of providing a nanotube or nanowire and forming a lipid bilayer around the polymer cushion. One embodiment provides a protein pore in the lipid bilayer. In one embodiment the protein pore is sensitive to specific agents

Noy, Aleksandr (Belmont, CA); Artyukhin, Alexander B. (Menlo Park, CA); Bakajin, Olgica (San Leandro, CA); Stoeve, Pieter (Davis, CA)

2009-08-04T23:59:59.000Z

11

Optical Determination of Gate--Tunable Bandgap in Bilayer Graphene  

E-Print Network [OSTI]

Tunable Bandgap in Bilayer Graphene Yuanbo Zhang* 1 , Tsung-gate-tunable bandgap in graphene bilayers with magnitude asbands. In two- dimensional graphene bilayers this bandgap

Zhang, Yuanbo

2010-01-01T23:59:59.000Z

12

Band Structure Asymmetry of Bilayer Graphene Revealed by Infrared Spectroscopy  

SciTech Connect (OSTI)

We report on infrared spectroscopy of bilayer graphene integrated in gated structures. We observe a significant asymmetry in the optical conductivity upon electrostatic doping of electrons and holes. We show that this finding arises from a marked asymmetry between the valence and conduction bands, which is mainly due to the inequivalence of the two sublattices within the graphene layer and the next-nearest-neighbor interlayer coupling. From the conductivity data, the energy difference of the two sublattices and the interlayer coupling energy are directly determined.

Li, Z.Q.; Henriksen, E.A.; Jiang, Z.; Hao, Zhao; Martin, Michael C.; Kim, P.; Stormer, H.L.; Basov, Dimitri N.

2008-12-10T23:59:59.000Z

13

Transverse electric plasmons in bilayer graphene  

E-Print Network [OSTI]

We predict the existence of transverse electric (TE) plasmons in bilayer graphene. We find that their plasmonic properties are much more pronounced in bilayer than in monolayer graphene, in a sense that they can get more ...

Jablan, Marinko

14

Bilayer Graphene Gets a Bandgap  

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 Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer GrapheneBilayer

15

STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS  

SciTech Connect (OSTI)

A bilayer electrolyte consisting of acceptor-doped ceria (on the fuel/reducing side) and cubic-stabilized bismuth oxide (on the oxidizing side) was developed. The bilayer electrolyte that was developed showed significant improvement in open-circuit potential versus a typical ceria based SOFC. Moreover, the OCP of the bilayer cells increased as the thickness of the bismuth oxide layer increased relative to the ceria layer. Thereby, verifying the bilayer concept. Although, because of the absence of a suitable cathode (a problem we are still working assiduously to solve), we were unable to obtain power density curves, our modeling work predicts a reduction in electrolyte area specific resistance of two orders of magnitude over cubic-stabilized zirconia and projects a maximum power density of 9 W/m{sup 2} at 800 C and 0.09 W/m{sup 2} at 500 C. Towards the development of the bilayer electrolyte other significant strides were made. Among these were, first, the development of a, bismuth oxide based, oxide ion conductor with the highest conductivity (0.56 S/cm at 800 C and 0.043 S/cm at 500 C) known to date. Second, a physical model of the defect transport mechanisms and the driving forces for the ordering phenomena in bismuth oxide and other fluorite systems was developed. Third, a model for point defect transport in oxide mixed ionic-electronic conductors was developed, without the typical assumption of a uniform distribution of ions and including the effect of variable loads on the transport properties of an SOFC (with either a single or bilayer electrolyte).

Eric D. Wachsman; Keith L. Duncan

2002-09-30T23:59:59.000Z

16

Twist Solves Bilayer Graphene Mystery  

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 Ferromagnetism in Layered NbS2TopoPortalBRDFTunableTurbulenceTwist Solves Bilayer

17

Bilayer Graphene Gets a Bandgap  

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 Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as Heat ShieldsBig»Bilayer

18

Bilayer Graphene Gets a Bandgap  

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 Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer Graphene Gets a

19

Bilayer Graphene Gets a Bandgap  

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 Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer Graphene Gets

20

Bilayer Graphene Gets a Bandgap  

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 Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer Graphene

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Bilayer Graphene Gets a Bandgap  

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 Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer

22

"Nanocrystal bilayer for tandem catalysis"  

SciTech Connect (OSTI)

Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

2011-01-24T23:59:59.000Z

23

Surface tension and electroporation of lipid bilayers  

E-Print Network [OSTI]

Electroporation of lipid bilayers is widely used in DNA transfection, gene therapy, and targeted drug delivery and has potential applications in water desalination and filtration. A better, more thorough molecular understanding ...

Cho, Han-Jae Jeremy

2011-01-01T23:59:59.000Z

24

Dynamic Morphologies of Microscale Droplet Interface Bilayers  

SciTech Connect (OSTI)

Droplet interface bilayers (DIBs) are a powerful platform for studying the dynamics of synthetic cellular membranes; however, very little has been done to exploit the unique dynamical features of DIBs. Here, we generate microscale droplet interface bilayers ( DIBs) by bringing together femtoliter-volume water droplets in a microfluidic oil channel, and characterize morphological changes of the DIBs as the droplets shrink due to evaporation. By varying the initial conditions of the system, we identify three distinct classes of dynamic morphology. (1) Buckling and Fission: When forming DIBs using the lipid-out method (lipids in oil phase), lipids in the shrinking monolayers continually pair together and slide into the bilayer to conserve their mass. As the bilayer continues to grow, it becomes confined, buckles, and eventually fissions one or more vesicles. (2) Uniform Shrinking: When using the lipid-in method (lipids in water phase) to form DIBs, lipids uniformly transfer from the monolayers and bilayer into vesicles contained inside the water droplets. (3) Stretching and Unzipping: Finally, when the droplets are pinned to the wall(s) of the microfluidic channel, the droplets become stretched during evaporation, culminating in the unzipping of the bilayer and droplet separation. These findings offer a better understanding of the dynamics of coupled lipid interfaces.

Mruetusatorn, Prachya [ORNL] [ORNL; Boreyko, Jonathan B [ORNL] [ORNL; Sarles, Stephen A [ORNL] [ORNL; Venkatesan, Guru [The University of Tennessee] [The University of Tennessee; Hayes, Douglas G [ORNL] [ORNL; Collier, Pat [ORNL] [ORNL

2014-01-01T23:59:59.000Z

25

Possible mechanism of adhesion in a mica supported phospholipid bilayer  

SciTech Connect (OSTI)

Phospholipid bilayers supported on hydrophilic solids like silica and mica play a substantial role in fundamental studies and technological applications of phospholipid membranes. In both cases the molecular mechanism of adhesion between the bilayer and the support is of primary interest. Since the possibilities of experimental methods in this specific area are rather limited, the methods of computer simulation acquire great importance. In this paper we use the grand canonical Monte Carlo technique and an atomistic force field to simulate the behavior of a mica supported phospholipid bilayer in pure water as a function of the distance between the bilayer and the support. The simulation reveals a possible adhesion mechanism, where the adhesion is due to individual lipid molecules that protrude from the bilayer and form widely spaced links with the support. Simultaneously, the bilayer remains separated from the bilayer by a thin water interlayer which maintains the bilayer fluidity.

Pertsin, Alexander, E-mail: ig3@ix.urz.uni-heidelberg.de [Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg (Germany) [Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg (Germany); Institute of Organo-Element Compounds, Russian Academy of Sciences, Vavilov Str. 28, 117991 Moscow (Russian Federation); Grunze, Michael [Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg (Germany) [Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg (Germany); Institute for Functional Interfaces, Karlsruhe Institute of Technology, Hermann-von- Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2014-05-14T23:59:59.000Z

26

Adsorption on tunable bilayer graphene: A model approach  

SciTech Connect (OSTI)

The problem of the adsorption of atoms on the surface of tunable bilayer graphene is considered within the context of Anderson's model. Analytical expressions for the densities of states of bilayer graphene and an adatom are derived, and the charge exchange between adatoms and bilayer graphene is studied. The charge of adatoms of some elements is estimated. The change induced in the density of states of tunable bilayer graphene by the adsorption of atoms is explored.

Alisultanov, Z. Z., E-mail: zaur0102@gmail.com [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

2013-07-15T23:59:59.000Z

27

hal00276997, Raman spectra of misoriented bilayer graphene  

E-Print Network [OSTI]

hal­00276997, version 1 ­ 5 May 2008 Raman spectra of misoriented bilayer graphene P. Poncharal 1 spectra from single layer graphene with a bilayer in which the two layers are arbitrarily misoriented to the similarity of the electronic structures of single layer graphene and misoriented bilayer graphene. Another

Paris-Sud XI, Université de

28

Bilayer graphene quantum dot defined by topgates  

SciTech Connect (OSTI)

We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK, the conductance underneath the grounded gates is suppressed, which we attribute to nearest neighbour hopping and strain-induced piezoelectric fields. The gate-layout can thus be used to define resistive regions by tuning into the corresponding temperature range. We use this method to define a quantum dot structure in bilayer graphene showing Coulomb blockade oscillations consistent with the gate layout.

Müller, André; Kaestner, Bernd; Hohls, Frank; Weimann, Thomas; Pierz, Klaus; Schumacher, Hans W., E-mail: hans.w.schumacher@ptb.de [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany)

2014-06-21T23:59:59.000Z

29

Brownian Ratchets: Molecular Separations in Lipid Bilayers  

E-Print Network [OSTI]

Brownian Ratchets: Molecular Separations in Lipid Bilayers Supported on Patterned Arrays Alexander van Oudenaarden and Steven G. Boxer* Brownian ratchets use a time-varying asymmetric potential that can be applied to separate diffusing particles or molecules. A new type of Brownian ratchet

Boxer, Steven G.

30

Budding of domains in mixed bilayer membranes  

E-Print Network [OSTI]

We propose a model that accounts for budding behavior of domains in lipid bilayers, where each of the bilayer leaflets has a coupling between its local curvature and local lipid composition. The compositional asymmetry between the two monolayers leads to an overall spontaneous curvature. The membrane free-energy contains three contributions: bending energy, line tension, and a Landau free-energy for a lateral phase separation. Within a mean-field treatment, we obtain various phase diagrams which contain fully-budded, dimpled and flat states. In particular, for some range of membrane parameters, the phase diagrams exhibit a tricritical behavior as well as three-phase coexistence region. The global phase diagrams can be divided into three types and are analyzed in terms of the curvature-composition coupling parameter and domain size.

Jean Wolff; Shigeyuki Komura; David Andelman

2015-01-10T23:59:59.000Z

31

Budding of domains in mixed bilayer membranes  

E-Print Network [OSTI]

We propose a model that accounts for budding behavior of domains in lipid bilayers, where each of the bilayer leaflets has a coupling between its local curvature and local lipid composition. The compositional asymmetry between the two monolayers leads to an overall spontaneous curvature. The membrane free-energy contains three contributions: bending energy, line tension, and a Landau free-energy for a lateral phase separation. Within a mean-field treatment, we obtain various phase diagrams which contain fully-budded, dimpled and flat states. In particular, for some range of membrane parameters, the phase diagrams exhibit a tricritical behavior as well as three-phase coexistence region. The global phase diagrams can be divided into three types and are analyzed in terms of the curvature-composition coupling parameter and domain size.

Jean Wolff; Shigeyuki Komura; David Andelman

2014-10-14T23:59:59.000Z

32

How Bilayer Graphene Got a Bandgap  

ScienceCinema (OSTI)

Graphene is the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But theres a catch: graphene has no bandgap. Now Feng Wang and his colleagues at Berkeley Lab and UC Berkeley have engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 milli-electron volts, which is the energy of infrared radiation.

Feng Wang

2010-01-08T23:59:59.000Z

33

How Bilayer Graphene Got a Bandgap  

ScienceCinema (OSTI)

Graphene is the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But theres a catch: graphene has no bandgap. Now Feng Wang and his colleagues at Berkeley Lab and UC Berkeley have engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 milli-electron volts, which is the energy of infrared radiation.

Wang, Feng

2013-05-29T23:59:59.000Z

34

Tunable fractional quantum Hall phases in bilayer graphene  

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

Coulomb interactions drive the existence of a correlated many-body state. Bilayer graphene represents a particularly interesting material in which to study the fractional...

35

E-Print Network 3.0 - acid bilayers observed Sample Search Results  

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

of Docosahexaenoic Acid-Containing Phospholipid Bilayers as Studied by 2H NMR... of vinyl perdeuterated arachidonic acid chains in bilayers of 1-palmitoyl-2-vinylperdeuterioara...

36

Slip corona surrounding bilayer graphene nanopore Yunwei Maob  

E-Print Network [OSTI]

Slip corona surrounding bilayer graphene nanopore Liang Qi,a Yunwei Maob and Ju Li*abc Received 5th of bilayer graphene (BLG) depend on the stacking order between the two layers. We introduce a new conceptual and low interlayer shear resistance between two adjacent layers of graphene. The continuum model also

Chen, Sow-Hsin

37

Hot Carrier-Assisted Intrinsic Photoresponse in Graphene  

E-Print Network [OSTI]

We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation (of wavelength 850 nanometers) at the p-n interface leads to striking ...

Gabor, Nathaniel M.

38

STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS  

SciTech Connect (OSTI)

Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible CO, HC, or NOx and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at lower temperatures tremendous benefits may be accrued, not the least of which is reduced cost. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research is to develop a stable high conductivity (>0.05 S cm{sup -1} at 550 C) electrolyte for lower temperature SOFCs. This objective is specifically directed toward meeting the lowest (and most difficult) temperature criteria for the 21st Century Fuel Cell Program. Meeting this objective provides a potential for future transportation applications of SOFCs, where their ability to directly use hydrocarbon fuels could permit refueling within the existing transportation infrastructure. In order to meet this objective we are developing a functionally gradient bilayer electrolyte comprised of bismuth oxide on the air side and ceria on the fuel side. Bismuth oxide and doped ceria are among the highest ionic conducting electrolytes and in fact bismuth oxide based electrolytes are the only known solid oxide electrolytes to have an ionic conductivity that meets the program conductivity goal. We have previously demonstrated that this concept works, that a bismuth oxide/ceria bilayer electrolyte provides near theoretical open circuit potential (OCP) and is stable for 1400 h of fuel cell operation under both open circuit and maximum power conditions. More recently, we developed a computer model to determine the defect transport in this bilayer and have found that a bilayer comprised primarily of the more conductive component (bismuth oxide) is stable for 500 C operation. In this first year of the project we are obtaining necessary thermochemical data to complete the computer model as well as initial SOFC results based on thick 1-2 mm single and bilayer ceria/bismuth oxide electrolytes. We will use the computer model to obtain the optimum relative layer thickness as a function of temperature and air/fuel conditions. SOFCs will be fabricated with 1-2 mm single and bilayer electrolytes based on the modeling results, tested for OCP, conductivity, and stability and compared against the predictions. The computer modeling is a continuation of previous work under support from GRI and the student was available at the inception of the contract. However, the experimental effort was delayed until the beginning of the Spring Semester because the contract was started in October, 2 months after the start of our Fall Semester, and after all of the graduate students were committed to other projects. The results from both of these efforts are described in the following two sections: (1) Experimental; and (2) Computer Modeling.

Eric D. Wachsman

2000-10-01T23:59:59.000Z

39

Chiral tunneling in single and bilayer graphene  

E-Print Network [OSTI]

We review chiral (Klein) tunneling in single-layer and bilayer graphene and present its semiclassical theory, including the Berry phase and the Maslov index. Peculiarities of the chiral tunneling are naturally explained in terms of classical phase space. In a one-dimensional geometry we reduced the original Dirac equation, describing the dynamics of charge carriers in the single layer graphene, to an effective Schr\\"odinger equation with a complex potential. This allowed us to study tunneling in details and obtain analytic formulas. Our predictions are compared with numerical results. We have also demonstrated that, for the case of asymmetric n-p-n junction in single layer graphene, there is total transmission for normal incidence only, side resonances are suppressed.

T. Tudorovskiy; K. J. A. Reijnders; M. I. Katsnelson

2011-06-15T23:59:59.000Z

40

Electrostatic and Magnetic Fields in Bilayer Graphene  

E-Print Network [OSTI]

We compute the transmission probability through rectangular potential barriers and p-n junctions in the presence of a magnetic and electric fields in bilayer graphene taking into account the full four bands of the energy spectrum. For energy E higher than the interlayer coupling $\\gamma_1 (E>\\gamma_1)$ two propagation modes are available for transport giving rise to four possible ways for transmission and reflection probabilities. However, when the energy is less then the height of the barrier the Dirac fermions exhibits transmission resonances and only one mode of propagation is available. We study the effect of the interlayer electrostatic potential $\\delta$ and the different geometry parameters of the barrier on the transmission probability.

Ahmed Jellal; Ilham Redouani; Hocine Bahlouli

2014-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Solid-supported phospholipid bilayers: separation matrix for proteomics applications  

E-Print Network [OSTI]

matrix. As a first step towards the purification of proteins, this work showed that streptavidin proteins doubly bound to a bilayer by a biotinylated lipid can be separated from streptavidin proteins which are singly bounded....

Diaz Vazquez, Arnaldo Joel

2009-05-15T23:59:59.000Z

42

Quantum phases of dipolar bosons in bilayer geometry  

E-Print Network [OSTI]

We investigate the quantum phases of hard-core dipolar bosons confined to a square lattice in a bilayer geometry. Using exact theoretical techniques, we discuss the many-body effects resulting from the pairing of particles ...

Safavi-Naini, Arghavan

43

Bilayer Membrane in Confined Geometry: Interlayer Slide and Steric Repulsion  

E-Print Network [OSTI]

We derived free energy functional of a bilayer lipid membrane from the first principles of elasticity theory. The model explicitly includes position-dependent mutual slide of monolayers and bending deformation. Our free energy functional of liquid-crystalline membrane allows for incompressibility of the membrane and vanishing of the in-plane shear modulus and obeys reflectional and rotational symmetries of the flat bilayer. Interlayer slide at the mid-plane of the membrane results in local difference of surface densities of the monolayers. The slide amplitude directly enters free energy via the strain tensor. For small bending deformations the ratio between bending modulus and area compression coefficient, Kb/KA, is proportional to the square of monolayer thickness, h. Using the functional we performed self-consistent calculation of steric potential acting on bilayer between parallel confining walls separated by distance 2d. We found that temperature-dependent curvature at the minimum of confining potential is enhanced four times for a bilayer with slide as compared with a unit bilayer. We also calculate viscous modes of bilayer membrane between confining walls. Pure bending of the membrane is investigated, which is decoupled from area dilation at small amplitudes. Three sources of viscous dissipation are considered: water and membrane viscosities and interlayer drag. Dispersion has two branches. Confinement between the walls modifies the bending mode with respect to membrane in bulk solution. Simultaneously, inter-layer slipping mode, damped by viscous drag, remains unchanged by confinement.

S. V. Baoukina; S. I. Mukhin

2004-03-28T23:59:59.000Z

44

Water permeation through stratum corneum lipid bilayers from atomistic simulations  

E-Print Network [OSTI]

Stratum corneum, the outermost layer of skin, consists of keratin filled rigid non-viable corneocyte cells surrounded by multilayers of lipids. The lipid layer is responsible for the barrier properties of the skin. We calculate the excess chemical potential and diffusivity of water as a function of depth in lipid bilayers with compositions representative of the stratum corneum using atomistic molecular dynamics simulations. The maximum in the excess free energy of water inside the lipid bilayers is found to be twice that of water in phospholipid bilayers at the same temperature. Permeability, which decreases exponentially with the free energy barrier, is reduced by several orders of magnitude as compared to with phospholipid bilayers. The average time it takes for a water molecule to cross the bilayer is calculated by solving the Smoluchowski equation in presence of the free energy barrier. For a bilayer composed of a 2:2:1 molar ratio of ceramide NS 24:0, cholesterol and free fatty acid 24:0 at 300K, we estimate the permeability P=3.7e-9 cm/s and the average crossing time \\tau_{av}=0.69 ms. The permeability is about 30 times smaller than existing experimental results on mammalian skin sections.

Chinmay Das; Peter D. Olmsted; Massimo G. Noro

2009-07-09T23:59:59.000Z

45

Optical Characterization of LipidOptical Characterization of Lipid Bilayers on Gold SurfacesBilayers on Gold Surfaces  

E-Print Network [OSTI]

East Lansing, MI Aaron J. Greiner, Angelines Castro Forero, R. Mark Worden, and Robert Y. Ofoli #12 electrochemical behavior in lipid bilayers · Optically characterize interfaces on semi-transparent gold using

46

Final Technical Report: Grain Boundary Complexions and Transitions in Doped Silicon  

SciTech Connect (OSTI)

This four-year research project has advanced the fundamental knowledge of grain boundary (GB) complexions (i.e., "two-dimensional interfacial phases") and associated GB "phase" transitions in several grounds. First, a bilayer interfacial phase, which had been directly observed by microscopy only in complex ceramic systems in prior studies, has been identified in simpler systems such as Au-doped Si and Bi-doped Ni in this study, where the interpretations of the their formation mechanisms and microscopic images are less equivocal. Second, convincing evidence for the existence of a first-order GB transition from a nominally "clean" GB to a bilayer adsorption interfacial phase has been revealed for Au-doped Si; the confirmation of the first-order nature of interfacial transitions at GBs, which was rare in prior studies, is scientifically significant and technologically important. Third, the bilayer interfacial phase discovered in Bi-doped Ni has been found to be the cause of the mysterious liquid metal embrittlement phenomenon in this system; the exact atomic level mechanism of this phenomenon has puzzled the materials and physics communities for over a century. Finally, significant advancements have been made to establish phenomenological thermodynamic models for GB complexions and transitions. Since GB complexions can control the transport, mechanical and physical properties of a broad range of metallic and ceramic materials, the fundamental knowledge generated by this project can have broad impacts on materials design in general. In this regard, understanding and controlling GB phase behaviors (complexions and transitions) can be an important component for the "Materials Genome" project.

Jian Luo

2012-10-15T23:59:59.000Z

47

Can adding oil control domain formation in binary amphiphile bilayers?  

E-Print Network [OSTI]

Bilayers formed of two species of amphiphile of different chain lengths may segregate into thinner and thicker domains composed predominantly of the respective species. Using a coarse-grained mean-field model, we investigate how mixing oil with the amphiphiles affects the structure and thickness of the bilayer at and on either side of the boundary between two neighbouring domains. In particular, we find that oil molecules whose chain length is close to that of the shorter amphiphiles segregate to the thicker domain. This smooths the surface of the hydrophobic bilayer core on this side of the boundary, reducing its area and curvature and their associated free-energy penalties. The smoothing effect is weaker for oil molecules that are shorter or longer than this optimum value: short molecules spread evenly through the bilayer, while long molecules swell the thicker domain, increasing the surface area and curvature of the bilayer core in the interfacial region. Our results show that adding an appropriate oil could make the formation of domain boundaries more or less favourable, raising the possibility of controlling the domain size distribution.

M. J. Greenall; C. M. Marques

2014-06-12T23:59:59.000Z

48

Direct Detection of Membrane Channels from Gels Using Water-in-Oil Droplet Bilayers  

E-Print Network [OSTI]

Direct Detection of Membrane Channels from Gels Using Water-in-Oil Droplet Bilayers Andrew J. Heron lipid bilayers serve as simplified models of biological membranes and are widely used for the electrical in many situations. Alternative emulsion-based approaches to forming bilayers have also been reported,15

Wallace, Mark

49

hal-00276997,version1-5May2008 Raman spectra of misoriented bilayer graphene  

E-Print Network [OSTI]

hal-00276997,version1-5May2008 Raman spectra of misoriented bilayer graphene P. Poncharal1 , A layer graphene with a bilayer in which the two layers are arbitrarily misoriented. The profiles of the 2 of the electronic structures of single layer graphene and misoriented bilayer graphene. Another new aspect

50

Can a Carbon Nanotube Pierce through a Phospholipid Bilayer?  

E-Print Network [OSTI]

Great efficiency to penetrate into living cells is attributed to carbon nanotubes due to a number of direct and indirect observations of carbon nanotubes inside the cells. However, a direct evidence of physical translocation of nanotubes through phospholipid bilayers and the exact microscopic mechanism of their penetration into cells are still lacking. In order to test one of the inferred translocation mechanisms, namely the spontaneous piercing through the membrane induced only by thermal motion, we calculate the energy cost associated with the insertion of a carbon nanotube into a model phospholipid bilayer using the Single Chain Mean Field theory which is particularly suitable for the accurate measurements of equilibrium free energies. We find that the energy cost of the bilayer rupture is quite high compared to the energy of thermal motion. This conclusion may indirectly support other energy dependent translocation mechanisms such as, for example, endocytosis.

Sergey Pogodin; Vladimir A. Baulin

2010-10-07T23:59:59.000Z

51

Surface tension in bilayer membranes with fixed projected area  

E-Print Network [OSTI]

We study the elastic response of bilayer membranes with fixed projected area to both stretching and shape deformations. A surface tension is associated to each of these deformations. By using model amphiphilic membranes and computer simulations, we are able to observe both the types of deformation, and thus, both the surface tensions, related to each type of deformation, are measured for the same system. These surface tensions are found to assume different values in the same bilayer membrane: in particular they vanish for different values of the projected area. We introduce a simple theory which relates the two quantities and successfully apply it to the data obtained with computer simulations.

Alberto Imparato

2006-04-05T23:59:59.000Z

52

Registered and antiregistered phase separation of mixed amphiphilic bilayers  

E-Print Network [OSTI]

We derive a mean-field free energy for phase separation in coupled bilayer leaflets. Our model accounts for amphiphile-level structure, in particular hydrophobic mismatch, which promotes $\\textit{antiregistration}$ (AR), in competition with the `direct' trans-midplane coupling usually studied, promoting registration (R). For phospholipid parameters equilibrium demixing is typically R, but hydrophobic mismatch favours metastable AR phases, which can cause a bilayer in the `spinodal region' to require nucleation in order to equilibrate. This provides a framework for understanding existing observations, elucidating a subtle, often overlooked competition of couplings, and a key role for phase transition kinetics in determining domain registration/antiregistration.

John J. Williamson; Peter D. Olmsted

2014-08-12T23:59:59.000Z

53

Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth  

SciTech Connect (OSTI)

Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

Batzill M.; Sutter P.; Dahal, A.; Addou, R.

2012-06-11T23:59:59.000Z

54

Electronic band structure of magnetic bilayer graphene superlattices  

SciTech Connect (OSTI)

Electronic band structure of the bilayer graphene superlattices with ?-function magnetic barriers and zero average magnetic flux is studied within the four-band continuum model, using the transfer matrix method. The periodic magnetic potential effects on the zero-energy touching point between the lowest conduction and the highest valence minibands of pristine bilayer graphene are exactly analyzed. Magnetic potential is shown also to generate the finite-energy touching points between higher minibands at the edges of Brillouin zone. The positions of these points and the related dispersions are determined in the case of symmetric potentials.

Pham, C. Huy; Nguyen, T. Thuong [Theoretical and Computational Physics Department, Institute of Physics, VAST, 10 Dao Tan, Ba Dinh Distr., Hanoi 10000 (Viet Nam); SISSA/International School for Advanced Study, Via Bonomea 265, I-34136 Trieste (Italy); Nguyen, V. Lien, E-mail: nvlien@iop.vast.ac.vn [Theoretical and Computational Physics Department, Institute of Physics, VAST, 10 Dao Tan, Ba Dinh Distr., Hanoi 10000 (Viet Nam); Institute for Bio-Medical Physics, 109A Pasteur, 1st Distr., Hochiminh City (Viet Nam)

2014-09-28T23:59:59.000Z

55

The component groups structure of DPPC bilayers obtained by specular neutron reflectometry  

E-Print Network [OSTI]

Specular neutron reflectometry (SNR) was measured on a system of a floating bilayer consisting of 1,2-dipalmitoyl-d62-\\textit{sn}-glycero-3-phosphocholine (d62-diC16:0PC) deposited over a 1,2-dibehenoyl-\\textit{sn}-glycero-3-phosphocholine (diC22:0PC) bilayer at 25 and 55 {\\deg}C. The internal structure of lipid bilayers was described by a one dimensional scattering length density profile (SLDP) model, originally developed for the evaluation of small angle scattering data. The corresponding model reflectivity curves successfully describe the experimental reflectivity curves of a supported bilayer in the gel phase and a system of a floating bilayer in the liquid crystalline phase. The reflectivity data from the supported bilayer were evaluated individually and served further as an input by the data treatment of floating bilayer reflectivity curves. The results yield internal structure of a deposited and floating bilayer on the level of component groups of lipid molecules. The obtained structure of the floating d62-diC16:0PC bilayer displays high resemblance to the bilayer structure in the form of unilamellar vesicles, however, simultaneously it shows rate of fluctuations in comparison to unilamellar vesicle bilayers.

Michal Beli?ka; Yuri Gerelli; Norbert Ku?erka; Giovanna Fragneto

2014-12-16T23:59:59.000Z

56

STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS  

SciTech Connect (OSTI)

Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible hydrocarbons, CO, or NO{sub x} and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at low to intermediate temperatures tremendous benefits may be accrued. At low temperatures, in particular, it becomes feasible to use ferritic steel for interconnects instead of expensive and brittle ceramic materials such as those based on LaCrO{sub 3}. In addition, sealing the fuel cell becomes easier and more reliable; rapid startup is facilitated; thermal stresses (e.g., those caused by thermal expansion mismatches) are reduced; radiative losses ({approx}T{sup 4}) become minimal; electrode sintering becomes negligible and (due to a smaller thermodynamic penalty) the SOFC operating cycle (heating from ambient) would be more efficient. Combined, all these improvements further result in reduced initial and operating costs. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research is to develop a stable high conductivity (> 0.05 S cm{sup -1} at {le} 550 C) electrolyte for lower temperature SOFCs. This objective is specifically directed toward meeting the lowest (and most difficult) temperature criteria for the 21st Century Fuel Cell Program. Meeting this objective provides a potential for future transportation applications of SOFCs, where their ability to directly use hydrocarbon fuels could permit refueling within the existing transportation infrastructure. In order to meet this objective we are developing a functionally gradient bilayer electrolyte comprised of a layer of erbia-stabilized bismuth oxide (ESB) on the oxidizing side and a layer of SDC or GDC on the reducing side, see Fig. 1. Bismuth oxide and doped ceria are among the highest ionic conducting electrolytes and in fact bismuth oxide based electrolytes are the only known solid oxide electrolytes to have an ionic conductivity that meets the program conductivity goal. In this arrangement, the ceria layer protects the bismuth oxide layer from decomposing by shielding it from very low P{sub O{sub 2}}'s and the ESB layer serves to block electronic flux through the electrolyte. This arrangement has two significant advantages over the YSZ/SDC bilayers investigated by others [1, 2]. The first advantage is that SDC is conductive enough to serve as an intermediate temperature SOFC electrolyte. Moreover, ESB is conductive enough to serve as a low temperature electrolyte. Consequently, at worst an SDC/ESB bilayered SOFC should have the conductivity of SDC but with improved efficiency due to the electronic flux barrier provided by ESB. The second advantage is that small (dopant) concentrations of SDC in ESB or ESB in SDC, have been found to have conductivities comparable to the host lattice [3, 4]. Therefore, if solid solutioning occurs at the SDC-ESB interface, it should not be detrimental to the performance of the bilayer. In contrast, solid solutions of SDC and YSZ have been found to be significantly less conductive than SDC or YSZ. Thus, it bears emphasizing that, at this time, only SDC/ESB electrolytes have potential in low temperature SOFC applications.

Eric D. Wachsman; Keith L. Duncan

2002-03-31T23:59:59.000Z

57

Registered and antiregistered phase separation of mixed amphiphilic bilayers  

E-Print Network [OSTI]

We derive a mean-field free energy for the phase behaviour of coupled bilayer leaflets, which is implicated in cellular processes and important to the design of artificial membranes. Our model accounts for amphiphile-level structural features, particularly hydrophobic mismatch, which promotes antiregistration (AR), in competition with the `direct' trans-midplane coupling usually studied, promoting registration (R). We show that the phase diagram of coupled leaflets allows multiple \\textit{metastable} coexistences, then illustrate the kinetic implications with a detailed study of a bilayer of equimolar overall composition. For approximate parameters estimated to apply to phospholipids, equilibrium coexistence is typically registered, but metastable antiregistered phases can be kinetically favoured by hydrophobic mismatch. Thus a bilayer in the spinodal region can require nucleation to equilibrate, in a novel manifestation of Ostwald's `rule of stages'. Our results provide a framework for understanding disparate existing observations, elucidating a subtle competition of couplings, and a key role for phase transition kinetics in bilayer phase behaviour.

John J. Williamson; Peter D. Olmsted

2015-03-12T23:59:59.000Z

58

Topological insulating phases in mono and bilayer graphene  

E-Print Network [OSTI]

We analyze the influence of different quadratic interactions giving rise to time reversal invariant topological insulating phases in mono and bilayer graphene. We make use of the effective action formalism to determine the dependence of the Chern Simons coefficient on the different interactions.

Alberto Cortijo; Adolfo G. Grushin; Maria A. H. Vozmediano

2010-11-20T23:59:59.000Z

59

Molecular friction and epitactic coupling between monolayers in supported bilayers  

E-Print Network [OSTI]

1535 Molecular friction and epitactic coupling between monolayers in supported bilayers R. Merkel un substrat de membrane couplée (Evans et Sackmann, 1988), on détermine la friction moléculaire coefficients de friction entre les couches en fixant la couche mononucléaire proximale sur le substrat par des

Boyer, Edmond

60

Berry phase and pseudospin winding number in bilayer graphene  

E-Print Network [OSTI]

Ever since the novel quantum Hall effect in bilayer graphene was discovered, and explained by a Berry phase of 2? [ K. S. Novoselov et al. Nat. Phys. 2 177 (2006)], it has been widely accepted that the low-energy electronic ...

Marzari, Nicola

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Selective Monosaccharide Transport through Lipid Bilayers Using Boronic Acid Carriers  

E-Print Network [OSTI]

Selective Monosaccharide Transport through Lipid Bilayers Using Boronic Acid Carriers Pamela R-one boronic acids were studied for their ability to transport saccharides in and out of liposomes. The rates transport. The order of transport selectivity was sorbitol > fructose > glucose. The disaccharides maltose

Smith, Bradley D.

62

Josephson inplane and tunneling currents in bilayer quantum Hall system  

SciTech Connect (OSTI)

A Bose-Einstein condensation is formed by composite bosons in the quantum Hall state. A composite boson carries the fundamental charge (–e). We investigate Josephson tunneling of such charges in the bilayer quantum Hall system at the total filling ? = 1. We show the existence of the critical current for the tunneling current to be coherent and dissipationless in tunneling experiments with various geometries.

Ezawa, Z. F. [Nishina Center, RIKEN, Saitama 351-0198 (Japan); Tsitsishvili, G. [Georgia Department of Physics, Tbilisi State University, Tbilisi 0179 (Georgia); Sawada, A. [Research Center for Low Temperature and Materials Sciences, Kyoto University, Kyoto 606-8501 (Japan)

2013-12-04T23:59:59.000Z

63

Quantum theory of bilayer quantum Hall smectics Emiliano Papa,1  

E-Print Network [OSTI]

of charge-density and position along each stripe edge. The soft modes associated with the broken symmetries spontaneous interlayer phase coherence and a sizable charge gap even at relatively large layer separations in very high mobility bilayer systems at dilution refrigerator temperatures as a function of layer

64

Isoelectronic co-doping  

DOE Patents [OSTI]

Isoelectronic co-doping of semiconductor compounds and alloys with deep acceptors and deep donors is used to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, N and Bi, to customize solar cells, thermal voltaic cells, light emitting diodes, photodetectors, and lasers on GaP, InP, GaAs, Ge, and Si substrates. Isoelectronically co-doped Group II-VI compounds and alloys are also included.

Mascarenhas, Angelo

2004-11-09T23:59:59.000Z

65

Hierarchy of fillings for FQHE in monolayer and in bilayer graphene: Explanation of $?=-\\frac{1}{2}$ fractional quantum Hall state in bilayer graphene  

E-Print Network [OSTI]

The commensurability condition is applied to determine the hierarchy of fractional fillings of Landau levels in monolayer and bilayer graphene. The filling rates for FQHE in graphene are found and illustrated in the first three Landau levels. The good agreement with the experimental data is achieved. The presence of even denominator filling fractions in the hierarchy for FQHE in bilayer graphene is explained.

Janusz Jacak; Lucjan Jacak

2015-02-04T23:59:59.000Z

66

Stacking-dependent electronic structure of bilayer silicene  

SciTech Connect (OSTI)

Bilayer silicene (BLS) is a class of material that possibly holds both topological and superconducting properties; however, its structure is not fully understood. By scanning stacking modes and lattice constants using first principles calculations, several meta-stable configurations are identified, including a slightly faulted-AA packing structure, named slide-2AA. Different from the metallic properties of conventional AA and AB stacking forms, band structure of slide-2AA bilayer presents a sizeable indirect energy gap of ?1.16?eV. A metal-semiconductor phase transition along the sliding pathway with a small energy barrier is also observed, indicating its electronic properties can be easily tuned by applying small shear force along the BLS surface plane. Such unique quantitative relationship of structure and electronic properties has profound implications in nanoelectronics and electromechanical devices.

Fu, Huixia; Zhang, Jin; Ding, Zijing; Li, Hui, E-mail: huili8@iphy.ac.cn, E-mail: smeng@iphy.ac.cn; Meng, Sheng, E-mail: huili8@iphy.ac.cn, E-mail: smeng@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-03-31T23:59:59.000Z

67

Band Tunneling through Double Barrier in Bilayer Graphene  

E-Print Network [OSTI]

By taking into account the full four band energy spectrum, we calculate the transmission probability and conductance of electrons across symmetric and asymmetric double potential barrier with a confined interlayer potential difference in bilayer graphene. For energies less than the interlayer coupling \\gamma_{1}, E \\gamma_{1}, we obtain four possible ways for transmission resulting from the two propagating modes. We compute the associated transmission probabilities as well as their contribution to the conductance, study the effect of the double barrier geometry.

Hasan A. Alshehab; Hocine Bahlouli; Abderrahim El Mouhafid; Ahmed Jellal

2014-01-20T23:59:59.000Z

68

Fast Membranes Hemifusion via Dewetting between Lipid Bilayers  

E-Print Network [OSTI]

The behavior of lipid bilayer is important to understand the functionality of cells like the trafficking of ions between cells. Standard procedures to explore the properties of lipid bilayer and hemifused states typically use either supported membranes or vesicles. Both techniques have several shortcoming in terms of bio relevance or accessibility for measurements. In this article the formation of individual free standing hemifused states between model cell membranes is studied using an optimized microfluidic scheme which allows for simultaneous optical and electrophysiological measurements. In a first step, two model membranes are formed at a desired location within a microfluidic device using a variation of the droplet interface bilayer (DiB) technique. In a second step, the two model membranes are brought into contact forming a single hemifused state. For all tested lipids, the hemifused state between free standing membranes form within hundreds of milliseconds, i.e. several orders of magnitude faster than reported in literature. The formation of a hemifused state is observed as a two stage process, whereas the second stage can be explained as a dewetting process in no-slip boundary condition. The formed hemifusion states are long living and a single fusion event can be observed when triggered by an applied electric field as demonstrated for monoolein.

Jose Nabor Vargas; Ralf Seemann; Jean-Baptiste Fleury

2014-09-20T23:59:59.000Z

69

antibacterial copper-nickel bilayers: Topics by E-print Network  

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

A. Haselwandter; Rob Phillips 2011-06-10 5 Transverse electric plasmons in bilayer graphene MIT - DSpace Summary: We predict the existence of transverse electric (TE) plasmons...

70

Hollow structures with bilayer graphene walls Peter J.F. Harris *  

E-Print Network [OSTI]

Hollow structures with bilayer graphene walls Peter J.F. Harris * Centre for Advanced Microscopy, J.J. Thomson Physical Laboratory, University of Reading, Whiteknights, Reading RG6 6AF, UK A R T I C L E I N F A B S T R A C T The formation of three-dimensional shell-like structures with bilayer graphene walls

Harris, Peter J F

71

Hierarchy of fillings for FQHE in monolayer and in bilayer graphene: Explanation of $\  

E-Print Network [OSTI]

The commensurability condition is applied to determine the hierarchy of fractional fillings of Landau levels in monolayer and bilayer graphene. The filling rates for FQHE in graphene are found and illustrated in the first three Landau levels. The good agreement with the experimental data is achieved. The presence of even denominator filling fractions in the hierarchy for FQHE in bilayer graphene is explained.

Jacak, Janusz

2015-01-01T23:59:59.000Z

72

Title: Electron-Hole Asymmetric Integer and Fractional Quantum Hall Effect in Bilayer Graphene  

E-Print Network [OSTI]

Title: Electron-Hole Asymmetric Integer and Fractional Quantum Hall Effect in Bilayer Graphene graphene is predicted to pro- duce novel and tunable FQH ground states. Here we present local electronic compressibility measurements of the FQH effect in the lowest Landau level of bilayer graphene. We observe

Yacoby, Amir

73

Carrier scattering, mobilities, and electrostatic potential in monolayer, bilayer, and trilayer graphene  

E-Print Network [OSTI]

graphene Wenjuan Zhu,* Vasili Perebeinos, Marcus Freitag, and Phaedon Avouris IBM Thomas J. Watson Research mobility in monolayer, bilayer, and trilayer graphene has been systematically studied. We found that as the carrier density increases, the mobility decreases for monolayer graphene, while it increases for bilayer

Perebeinos, Vasili

74

Lipid Bilayer Structure Determined by the Simultaneous Analysis of Neutron and X-Ray Scattering Data  

E-Print Network [OSTI]

Lipid Bilayer Structure Determined by the Simultaneous Analysis of Neutron and X-Ray Scattering) and dipalmitoylphosphatidylcholine (DPPC) bilayers by simultaneously analyzing x-ray and neutron scattering data. The neutron data electron and neutron scattering density profiles. A key result of the analysis is the molecular surface

Nagle, John F.

75

Exchange bias and blocking temperature distribution of Fe-film/CoO-nanoparticle hybrid bilayers  

E-Print Network [OSTI]

relaxation in a Fe-film/CoO-nanoparticle hybrid system Appl. Phys. Lett. 101, 132401 (2012); 10 anisotropy energy per unit volume and V is the grain volume. Therefore, hybrid EB bilayers with the AF layer beExchange bias and blocking temperature distribution of Fe-film/CoO-nanoparticle hybrid bilayers Wei

Krishnan, Kannan M.

76

Production of microporous aluminum oxide electrodes as supports for tethered lipid bilayers of large surface area.  

E-Print Network [OSTI]

1 Production of microporous aluminum oxide electrodes as supports for tethered lipid bilayers.Bourdillon@utc.fr Abstract A composite electrode made by association of gold and porous aluminum oxide has been used aluminum oxide; phospholipid bilayer; two-dimensional electrochemistry; ubiquinone lateral mobility. 1

Paris-Sud XI, Université de

77

Size-dependent ultrafast structural dynamics inside phospholipid vesicle bilayers measured with 2D IR  

E-Print Network [OSTI]

Size-dependent ultrafast structural dynamics inside phospholipid vesicle bilayers measured with 2D 25, 2013) The ultrafast structural dynamics inside the bilayers of dilauroyl- phosphatidylcholine was used as a vibrational probe and provided information on spectral diffusion (structural dynam- ics

Fayer, Michael D.

78

Development of a Microfluidic Device for Synthesis of Lipid Bi-Layer In-Situ  

E-Print Network [OSTI]

and result in unstable bi-layers having a short lifetime. In this investigation a novel microfluidic device and a method for artificial synthesis of lipid bi-layer in-situ are explored. In the proposed method, lipid trapped at an aperture on a Teflon sheet...

Banneyake, Bm U.

2010-01-14T23:59:59.000Z

79

Specific heat of twisted bilayer graphene: Engineering phonons by atomic plane rotations  

SciTech Connect (OSTI)

We have studied the phonon specific heat in single-layer, bilayer, and twisted bilayer graphene. The calculations were performed using the Born-von Karman model of lattice dynamics for intralayer atomic interactions and spherically symmetric interatomic potential for interlayer interactions. We found that at temperature T?bilayer graphene, and n?=?1.3 for the twisted bilayer graphene. The phonon specific heat reveals an intriguing dependence on the twist angle in bilayer graphene, which is particularly pronounced at low temperature. The results suggest a possibility of phonon engineering of thermal properties of layered materials by twisting the atomic planes.

Nika, Denis L. [E. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Department of Physics and Engineering, Moldova State University, Chisinau MD-2009, Republic of Moldova (Moldova, Republic of); Nano-Device Laboratory, Department of Electrical Engineering and Materials Science and Engineering Program, Bourns College of Engineering, University of California—Riverside, Riverside, California, 92521 (United States); Cocemasov, Alexandr I. [E. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Department of Physics and Engineering, Moldova State University, Chisinau MD-2009, Republic of Moldova (Moldova, Republic of); Balandin, Alexander A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory, Department of Electrical Engineering and Materials Science and Engineering Program, Bourns College of Engineering, University of California—Riverside, Riverside, California, 92521 (United States)

2014-07-21T23:59:59.000Z

80

Crystalline silicon growth in nickel/a-silicon bilayer  

SciTech Connect (OSTI)

The effect of substrate temperature on amorphous Silicon crystallization, mediated by metal impurity is reported. Bilayers of Ni(200nm)/Si(400nm) are deposited on fused silica substrate by electron beam evaporator at 200 and 500 Degree-Sign C. Raman mapping shows that, 2 to 5 micron size crystalline silicon clusters are distributed over the entire surface of the sample. X-ray diffraction and X-ray absorption spectroscopy studies demonstrate silicon crystallizes over the metal silicide seeds and grow with the annealing temperature.

Mohiddon, Md Ahamad; Naidu, K. Lakshun [School of Physics, University of Hyderabad, Hyderabad-500046 (India) and Department of Physics, University of Trento, 38123 POVO (Trento) (Italy); Dalba, G. [Department of Physics, University of Trento, 38123 POVO (Trento) (Italy); Rocca, F. [IFN-CNR, Institute for Photonics and Nanotechnologies, Unit FBK-Photonics of Trento, 38123, Trento (Italy); Krishna, M. Ghanashyam [School of Physics, University of Hyderabad, Hyderabad-500046 (India)

2013-02-05T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Interdiffusion at the bilayer polymer interface: Evidence for reptation. [NEUTRONS  

SciTech Connect (OSTI)

Neutron reflection is used to study the interdiffusion in equal molecular weight polystyrene bilayer melts with a spatial resolution of 1nm. Interfacial widths and concentration profiles at the bilayer interface are obtained for annealing times up to and beyond the time (reptation time, {tau}{sub d}) in which the molecule has moved by its own length. For annealing times t < {tau}{sub d}, the reptation model predicts a mean square displacement of monomers whose time evolution is a power law. The detailed profile is expected to exhibit a discontinuity (sharp gradient) of density at the interface between the two polymers. For relatively light weight polymers of M {approx} 233,000, the mean square displacements of monomers is in general agreement with reptation predictions; the discontinuity at the interface is only observed when the molecular weights are large, M {approx} 1,000,000. The discontinuity is present even for low concentrations of the deuterated polymer where isotopic slowing down effects are negligible, thus confirming the sharp gradient as being due to reptation. 19 refs., 5 figs.

Felcher, G.P.; Karim, A. (Argonne National Lab., IL (USA)); Russell, T.P. (IBM Research Div., San Jose, CA (USA). Almaden Research Center)

1990-06-01T23:59:59.000Z

82

Corrugation of Phase-Separated Lipid Bilayers Supported by Nanoporous Silica Xerogel Surfaces  

SciTech Connect (OSTI)

Lipid bilayers supported by substrates with nanometer-scale surface corrugations holds interest in understanding both nanoparticle-membrane interactions and the challenges of constructing models of cell membranes on surfaces with desirable properties, e.g. porosity. Here, we successfully form a two-phase (gel-fluid) lipid bilayer supported by nanoporous silica xerogel. Surface topology, diffusion, and lipid density in comparison to mica-supported lipid bilayers were characterized by AFM, FRAP, FCS, and quantitative fluorescence microscopy, respectively. We found that the two-phase lipid bilayer follows the xerogel surface contours. The corrugation imparted on the lipid bilayer results in a lipid density that is twice that on a flat mica surface. In direct agreement with the doubling of actual bilayer area in a projected area, we find that the lateral diffusion coefficient (D) of lipids on xerogel ({approx}1.7 {micro}m{sup 2}/s) is predictably lower than on mica ({approx}4.1 {micro}m{sup 2}/s) by both FRAP and FCS techniques. Furthermore, the gel-phase domains on xerogel compared to mica were larger and less numerous. Overall, our results suggest the presence of a relatively defect-free continuous two-phase bilayer that penetrates approximately midway into the first layer of {approx}50 nm xerogel beads.

Goksu, E I; Nellis, B A; Lin, W; Satcher Jr., J H; Groves, J T; Risbud, S H; Longo, M L

2008-10-30T23:59:59.000Z

83

The Molecular Structure of a Phosphatidylserine Bilayer Determined by Scattering and Molecular Dynamics Simulations  

SciTech Connect (OSTI)

Phosphatidylserine (PS) lipids play essential roles in biological processes, including enzyme activation and apoptosis. We report on the molecular structure and atomic scale interactions of a fluid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS). A scattering density profile model, aided by molecular dynamics (MD) simulations, was developed to jointly refine different contrast small-angle neutron and X-ray scattering data, which yielded a lipid area of 62.7 A2 at 25 C. MD simulations with POPS lipid area constrained at different values were also performed using all-atom and aliphatic united-atom models. The optimal simulated bilayer was obtained using a model-free comparison approach. Examination of the simulated bilayer, which agrees best with the experimental scattering data, reveals a preferential interaction between Na+ ions and the terminal serine and phosphate moieties. Long-range inter-lipid interactions were identified, primarily between the positively charged ammonium, and the negatively charged carboxylic and phosphate oxygens. The area compressibility modulus KA of the POPS bilayer was derived by quantifying lipid area as a function of surface tension from area-constrained MD simulations. It was found that POPS bilayers possess a much larger KA than that of neutral phosphatidylcholine lipid bilayers. We propose that the unique molecular features of POPS bilayers may play an important role in certain physiological functions.

Pan, Jianjun [University of South Florida, Tampa (USF)] [University of South Florida, Tampa (USF); Cheng, Xiaolin [ORNL] [ORNL; Monticelli, Luca [Institut National de la Santé et de la Recherche Médicale (INSERM) and INTS, France] [Institut National de la Santé et de la Recherche Médicale (INSERM) and INTS, France; Heberle, Frederick A [ORNL] [ORNL; Kucerka, Norbert [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,] [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,; Tieleman, D. Peter [University of Calgary, ALberta, Canada] [University of Calgary, ALberta, Canada; Katsaras, John [ORNL] [ORNL

2014-01-01T23:59:59.000Z

84

Passivating overcoat bilayer for multilayer reflective coatings for extreme ultraviolet lithography  

DOE Patents [OSTI]

A passivating overcoat bilayer is used for multilayer reflective coatings for extreme ultraviolet (EUV) or soft x-ray applications to prevent oxidation and corrosion of the multilayer coating, thereby improving the EUV optical performance. The overcoat bilayer comprises a layer of silicon or beryllium underneath at least one top layer of an elemental or a compound material that resists oxidation and corrosion. Materials for the top layer include carbon, palladium, carbides, borides, nitrides, and oxides. The thicknesses of the two layers that make up the overcoat bilayer are optimized to produce the highest reflectance at the wavelength range of operation. Protective overcoat systems comprising three or more layers are also possible.

Montcalm, Claude (Livermore, CA); Stearns, Daniel G. (Los Altos, CA); Vernon, Stephen P. (Pleasanton, CA)

1999-01-01T23:59:59.000Z

85

Ag and Au atoms intercalated in bilayer heterostructures of transition metal dichalcogenides and graphene  

SciTech Connect (OSTI)

The diffusive motion of metal nanoparticles Au and Ag on monolayer and between bilayer heterostructures of transition metal dichalcogenides and graphene are investigated in the framework of density functional theory. We found that the minimum energy barriers for diffusion and the possibility of cluster formation depend strongly on both the type of nanoparticle and the type of monolayers and bilayers. Moreover, the tendency to form clusters of Ag and Au can be tuned by creating various bilayers. Tunability of the diffusion characteristics of adatoms in van der Waals heterostructures holds promise for controllable growth of nanostructures.

Iyikanat, F., E-mail: fadiliyikanat@iyte.edu.tr; Senger, R. T. [Department of Physics, Izmir Institute of Technology, 35430 Izmir (Turkey); Sahin, H., E-mail: hasan.sahin@uantwerpen.be; Peeters, F. M. [Department of Physics, University of Antwerp, 2610 Antwerp (Belgium)

2014-09-01T23:59:59.000Z

86

Axially Tapered And Bilayer Microchannels For Evaporative Cooling Devices  

DOE Patents [OSTI]

The invention consists of an evaporative cooling device comprising one or more microchannels whose cross section is axially reduced to control the maximum capillary pressure differential between liquid and vapor phases. In one embodiment, the evaporation channels have a rectangular cross section that is reduced in width along a flow path. In another embodiment, channels of fixed width are patterned with an array of microfabricated post-like features such that the feature size and spacing are gradually reduced along the flow path. Other embodiments incorporate bilayer channels consisting of an upper cover plate having a pattern of slots or holes of axially decreasing size and a lower fluid flow layer having channel widths substantially greater than the characteristic microscale dimensions of the patterned cover plate. The small dimensions of the cover plate holes afford large capillary pressure differentials while the larger dimensions of the lower region reduce viscous flow resistance.

Nilson, Robert (Cardiff, CA); Griffiths, Stewart (Livermore, CA)

2005-10-04T23:59:59.000Z

87

Realization of free-standing silicene using bilayer graphene  

SciTech Connect (OSTI)

The available synthesized silicene-like structures have been only realized on metallic substrates which are very different from the standalone buckled silicene, e.g., the Dirac cone of silicene is destroyed due to lattice distortion and the interaction with the substrate. Using graphene bilayer as a scaffold, a route is proposed to synthesize silicene with electronic properties decoupled from the substrate. The buckled hexagonal arrangement of silicene between the graphene layers is found to be very similar to the theoretically predicted standalone buckled silicene which is only very weakly van der Waals coupled to the graphene layers with a graphite-like interlayer distance of 3.42?Å and without any lattice distortion. We found that these stacked layers are stable well above room temperature.

Neek-Amal, M. [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium) [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Department of Physics, Shahid Rajaee Teacher Training University, Lavizan, Tehran 16785-136 (Iran, Islamic Republic of); Sadeghi, A. [Department of Physics, Basel University, Klingelbergestrasse 82, CH-4056 Basel (Switzerland)] [Department of Physics, Basel University, Klingelbergestrasse 82, CH-4056 Basel (Switzerland); Berdiyorov, G. R.; Peeters, F. M. [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)] [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)

2013-12-23T23:59:59.000Z

88

Independent Manipulation of Electric and Thermal Fields with Bilayer Structure  

E-Print Network [OSTI]

Recently, increasing attention has been focused on the employment of transformation and metamaterial for manipulation of various physical fields, which requires complicated configuration and usually limits in single field. Here, for the first time, we propose and experimentally demonstrated bilayer structure to achieve simultaneously independent manipulation of multi-physics field (dc electric fields and thermal) by directly solving the dc electric/ thermal field equations. This structure is composed of two layers: the outer layer is made of isotropic and homogeneous material, while the inner layer is fan-shape layer. Since it is not based on TO, it can be readily experimentally fabricated with naturally occurring materials. Experimentally, we has designed, fabricated and characterized two structures simultaneously behaving as dc electric cloak/ thermal concentrator and dc electric concentrator/ thermal cloak, respectively. The simulation results agree well with the experiment ones, thus confirming the feasib...

Lan, Chuwen; Wu, Lingling; Li, Bo; Zhou, Ji

2015-01-01T23:59:59.000Z

89

Correlation effects in (111) bilayers of perovskite transition-metal oxides  

SciTech Connect (OSTI)

We investigate the correlation-induced Mott, magnetic, and topological phase transitions in artificial (111) bilayers of perovskite transition-metal oxides LaAuO3 and SrIrO3 for which the previous density-functional theory calculations predicted topological insulating states. Using the dynamical-mean-field theory with realistic band structures and Coulomb interactions, LaAuO3 bilayer is shown to be far away from a Mott insulating regime, and a topological-insulating state is robust. On the other hand, SrIrO3 bilayer is on the verge of an orbital-selective topological Mott transition and turns to a trivial insulator by an antiferromagnetic ordering. Oxide bilayers thus provide a novel class of topological materials for which the interplay between the spin-orbit coupling and electron-electron interactions is a fundamental ingredient.

Okamoto, Satoshi [ORNL] [ORNL; Zhu, Wenguang [University of Science and Technology of China] [University of Science and Technology of China; Nomura, Yusuke [University of Tokyo, Japan] [University of Tokyo, Japan; Arita, R. [University of Tokyo, Japan] [University of Tokyo, Japan; Xiao, Di [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU); Nagaosa, Naoto [University of Tokyo, Japan] [University of Tokyo, Japan

2014-01-01T23:59:59.000Z

90

Unraveling the interlayer-related phonon self-energy renormalization in bilayer graphene  

E-Print Network [OSTI]

In this letter, we present a step towards understanding the bilayer graphene (2LG) interlayer (IL)-related phonon combination modes and overtones as well as their phonon self-energy renormalizations by using both gate-modulated ...

Araujo, Paulo Antonio Trinidade

91

Bilayer graphene growth by low pressure chemical vapor deposition on copper foil  

E-Print Network [OSTI]

Successfully integrating graphene in standard processes for applications in electronics relies on the synthesis of high-quality films. In this work we study Low Pressure Chemical Vapor Deposition (LPCVD) growth of bilayer ...

Fang, Wenjing, S.M. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

92

Zone folding effect in Raman G-band intensity of twisted bilayer graphene  

E-Print Network [OSTI]

The G-band Raman intensity is calculated for twisted bilayer graphene as a function of laser excitation energy based on the extended tight binding method. Here we explicitly consider the electron-photon and electron-phonon ...

Dresselhaus, Mildred

93

Effects of Carbon Nanotubes in Barrier Epithelial Cells via Effects on Lipid Bilayers Shanta Lewis1  

E-Print Network [OSTI]

Effects of Carbon Nanotubes in Barrier Epithelial Cells via Effects on Lipid Bilayers Shanta Lewis1 Physiology, IU School of Medicine Carbon nanotubes (CNTs) are one of many nanoparticles (NP) which are being

Zhou, Yaoqi

94

Infrared Spectroscopic Characterization of Lipid-Alkylsiloxane Hybrid Bilayer Membranes at Oxide  

E-Print Network [OSTI]

Infrared Spectroscopic Characterization of Lipid-Alkylsiloxane Hybrid Bilayer Membranes at Oxide and Gm1/OTS/SiO2/Si, were characterized using a combined application of infrared spectroscopy, null

Parikh, Atul N.

95

Buckling analysis of singly curved shallow bi-layered arch under concentrated loading  

E-Print Network [OSTI]

viable alternative to conventional sandwich materials in applications where the functional requirements can be met without the second face sheet of the sandwich. For structural applications bi-layered materials are required to have oil canning...

Sonawane, Mahesh

2009-05-15T23:59:59.000Z

96

Enhanced sensitivity of a microfabricated resonator using a graphene-polystyrene bilayer membrane  

SciTech Connect (OSTI)

A graphene layer was synthesized using chemical vapor deposition methods and a polystyrene solution was spin-cast onto the graphene film. The graphene-polystyrene bilayer membrane was attached between the two tines of a microfabricated quartz tuning fork (QTF). The modulus of the graphene-polystyrene bilayer was measured to be twice that of a pristine polystyrene membrane. Exposure of the membrane-coated QTF to ethanol vapor decreased the resonance frequency of the microresonator. The bilayer membrane-coated QTF produced a frequency change that was three times the change obtained using a polystyrene membrane-coated QTF, with a lower degree of degradation in the Q factor. The limit of detection of the bilayer membrane-coated QTF to ethanol vapor was determined to be 20?ppm.

Yun, Minhyuk; Lee, Eunho; Cho, Kilwon; Jeon, Sangmin, E-mail: jeons@postech.ac.kr [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang (Korea, Republic of)

2014-08-18T23:59:59.000Z

97

Debonding in bi-layer material systems under moisture effect : a multiscale approach  

E-Print Network [OSTI]

Bi-layer material systems are found in various engineering applications ranging from nano-scale components, such as thin films in circuit boards, to macro-scale structures such as adhesive bonding in aerospace and civil ...

Lau, Tak-bun, Denvid

2012-01-01T23:59:59.000Z

98

Nitrogen-doped Graphene and Its Electrochemical Applications...  

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

doped Graphene and Its Electrochemical Applications. Nitrogen-doped Graphene and Its Electrochemical Applications. Abstract: Nitrogen-doped graphene (N-graphene) is obtained by...

99

Nitrogen-Doped Graphene and its Application in Electrochemical...  

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

Doped Graphene and its Application in Electrochemical Biosensing. Nitrogen-Doped Graphene and its Application in Electrochemical Biosensing. Abstract: Chemical doping with foreign...

100

Indium doped zinc oxide nanowire thin films for antireflection and solar absorber coating applications  

SciTech Connect (OSTI)

Indium doped ZnO nanowire thin films were prepared by thermal oxidation of Zn-In metal bilayer films at 500°C. The ZnO:In nanowires are 20-100 nm in diameter and several tens of microns long. X-ray diffraction patterns confirm the formation of oxide and indicate that the films are polycrystalline, both in the as deposited and annealed states. The transmission which is <2% for the as deposited Zn-In films increases to >90% for the ZnO:In nanowire films. Significantly, the reflectance for the as deposited films is < 10% in the region between 200 to 1500 nm and < 2% for the nanowire films. Thus, the as deposited films can be used solar absorber coatings while the nanowire films are useful for antireflection applications. The growth of nanowires by this technique is attractive since it does not involve very high temperatures and the use of catalysts.

Shaik, Ummar Pasha [ACRHEM, University of Hyderabad, Hyderabad-500046 (India); Krishna, M. Ghanashyam, E-mail: mgksp@uohyd.ac.in [ACRHEM and School of Physics, University of Hyderabad, Hyderabad-500046 (India)

2014-04-24T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Optical Properties and Potential Applications of Doped Semiconductor...  

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

Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Abstract:...

102

General model of phospholipid bilayers in fluid phase within the single chain mean field theory  

SciTech Connect (OSTI)

Coarse-grained model for saturated phospholipids: 1,2-didecanoyl-sn-glycero-3-phosphocholine (DCPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and unsaturated phospholipids: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2- dioleoyl-sn-glycero-3-phosphocholine (DOPC) is introduced within the single chain mean field theory. A single set of parameters adjusted for DMPC bilayers gives an adequate description of equilibrium and mechanical properties of a range of saturated lipid molecules that differ only in length of their hydrophobic tails and unsaturated (POPC, DOPC) phospholipids which have double bonds in the tails. A double bond is modeled with a fixed angle of 120°, while the rest of the parameters are kept the same as saturated lipids. The thickness of the bilayer and its hydrophobic core, the compressibility, and the equilibrium area per lipid correspond to experimentally measured values for each lipid, changing linearly with the length of the tail. The model for unsaturated phospholipids also fetches main thermodynamical properties of the bilayers. This model is used for an accurate estimation of the free energies of the compressed or stretched bilayers in stacks or multilayers and gives reasonable estimates for free energies. The proposed model may further be used for studies of mixtures of lipids, small molecule inclusions, interactions of bilayers with embedded proteins.

Guo, Yachong; Baulin, Vladimir A. [Departament d’Enginyeria Química, Universitat Rovira i Virgili, Av. dels Paisos Catalans 26, 43007 Tarragona (Spain)] [Departament d’Enginyeria Química, Universitat Rovira i Virgili, Av. dels Paisos Catalans 26, 43007 Tarragona (Spain); Pogodin, Sergey [Institute of Chemical Research of Catalonia, ICIQ, Av. Paisos Catalans 16, 43007 Tarragona (Spain)] [Institute of Chemical Research of Catalonia, ICIQ, Av. Paisos Catalans 16, 43007 Tarragona (Spain)

2014-05-07T23:59:59.000Z

103

Nanoporous microbead supported bilayers: stability, physical characterization, and incorporation of functional transmembrane proteins.  

SciTech Connect (OSTI)

The introduction of functional transmembrane proteins into supported bilayer-based biomimetic systems presents a significant challenge for biophysics. Among the various methods for producing supported bilayers, liposomal fusion offers a versatile method for the introduction of membrane proteins into supported bilayers on a variety of substrates. In this study, the properties of protein containing unilamellar phosphocholine lipid bilayers on nanoporous silica microspheres are investigated. The effects of the silica substrate, pore structure, and the substrate curvature on the stability of the membrane and the functionality of the membrane protein are determined. Supported bilayers on porous silica microspheres show a significant increase in surface area on surfaces with structures in excess of 10 nm as well as an overall decrease in stability resulting from increasing pore size and curvature. Comparison of the liposomal and detergent-mediated introduction of purified bacteriorhodopsin (bR) and the human type 3 serotonin receptor (5HT3R) are investigated focusing on the resulting protein function, diffusion, orientation, and incorporation efficiency. In both cases, functional proteins are observed; however, the reconstitution efficiency and orientation selectivity are significantly enhanced through detergent-mediated protein reconstitution. The results of these experiments provide a basis for bulk ionic and fluorescent dye-based compartmentalization assays as well as single-molecule optical and single-channel electrochemical interrogation of transmembrane proteins in a biomimetic platform.

Davis, Ryan W. (University of New Mexico, Albuquerque, NM); Brozik, James A. (University of New Mexico, Albuquerque, NM); Brozik, Susan Marie; Cox, Jason M. (University of New Mexico, Albuquerque, NM); Lopez, Gabriel P. (University of New Mexico, Albuquerque, NM); Barrick, Todd A. (University of New Mexico, Albuquerque, NM); Flores, Adrean (University of New Mexico, Albuquerque, NM)

2007-03-01T23:59:59.000Z

104

PHYSICAL REVIEW B 85, 205443 (2012) Growth structure and work function of bilayer graphene on Pd(111)  

E-Print Network [OSTI]

PHYSICAL REVIEW B 85, 205443 (2012) Growth structure and work function of bilayer graphene on Pd of bilayer graphene on Pd(111). Low-energy electron diffraction analysis established that the two graphene layer. We propose that the faceted shapes are due to the zigzag-terminated edges bounding graphene

Ciobanu, Cristian

105

Anisotropic Motion and Molecular Dynamics of Cholesterol, Lanosterol, and Ergosterol in Lecithin Bilayers Studied by Quasi-elastic Neutron Scattering  

E-Print Network [OSTI]

Bilayers Studied by Quasi-elastic Neutron Scattering Emil Endress, Helmut Heller,§ He´le`ne CasaltaVised Manuscript ReceiVed June 27, 2002 ABSTRACT: Quasi-elastic neutron scattering (QENS) was employed to study of motion within the bilayer on the molecular dynamics time scale. In a recent quasi-elastic neutron

Brown, Michael F.

106

PHYSICAL REVIEW B 83, 193403 (2011) First-principles study of strain-induced modulation of energy gaps of graphene/BN and BN bilayers  

E-Print Network [OSTI]

gaps of graphene/BN and BN bilayers Xiaoliang Zhong, Yoke Khin Yap, and Ravindra Pandey* Department May 2011) First-principles calculations based on density functional theory are performed on graphene/BN and BN bilayers to investigate the effect of the strain on their energy gaps. For the graphene/BN bilayer

Pandey, Ravi

2011-01-01T23:59:59.000Z

107

BI-LAYER p-n JUNCTION INTERCONNECTIONS FOR COAL BASED SOLID OXIDE FUEL CELLS  

SciTech Connect (OSTI)

In this report, a new approach for lower operating temperature solid oxide fuel cells (SOFCs) interconnections (IC) consisting of a bi-layer structure is proposed and analyzed. The bi-layer structure consists of a p-type layer exposed to cathodic gas (air/oxygen) and an n-type layer exposed to anodic gas (fuel). It is theoretically shown that the interfacial oxygen partial pressure which is an important design variable, is dependent primarily on the oxygen partial pressure gradient across the IC, the low level oxygen conductivities of the two layers and is largely independent of their electronic conductivities and the total current density through the IC material. Experimental difficulties in fabricating bi-layer structures are presently being addressed.

Srikanth Gopalan

2005-01-29T23:59:59.000Z

108

Air-stable droplet interface bilayers on oil-infused surfaces  

SciTech Connect (OSTI)

Droplet interface bilayers (DIBs) are versatile model membranes useful for synthetic biology and biosensing; however, to date they have always been confined to fluid reservoirs. Here, we demonstrate that when two or more water droplets collide on an oil-infused substrate, they exhibit non-coalescence due to the formation of a thin oil film that gets squeezed between the droplets from the bottom-up. We show that when phospholipids are included in the water droplets, a stable droplet interface bilayer forms between the non-coalescing water droplets. As with traditional oil-submerged DIBs, we were able to characterize ion channel transport by incorporating peptides into each droplet. Our findings reveal that droplet interface bilayers can function in air environments, which could potentially enable biosensing of atmospheric particulates.

Boreyko, Jonathan B [ORNL] [ORNL; Polizos, Georgios [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Datskos, Panos G [ORNL] [ORNL; Sarles, Stephen A [ORNL] [ORNL; Collier, Pat [ORNL] [ORNL

2014-01-01T23:59:59.000Z

109

Effects of Sugars on Lipid Bilayers during Dehydration ? SAXS/WAXS Measurements and Quantitative Model  

SciTech Connect (OSTI)

We present an X-ray scattering study of the effects of dehydration on the bilayer and chain-chain repeat spacings of dipalmitoylphosphatidylcholine bilayers in the presence of sugars. The presence of sugars has no effect on the average spacing between the phospholipid chains in either the fluid or gel phase. Using this finding, we establish that for low sugar concentrations only a small amount of sugar exclusion occurs. Under these conditions, the effects of sugars on the membrane transition temperatures can be explained quantitatively by the reduction in hydration repulsion between bilayers due to the presence of the sugars. Specific bonding of sugars to lipid headgroups is not required to explain this effect.

Lenne, Thomas; Garvey, Christopher J.; Koster, Karen L.; Bryant, Gary; (ANSTO); (USD); (RMIT)

2009-04-02T23:59:59.000Z

110

Transfer matrix theory of monolayer graphene/bilayer graphene heterostructure superlattice  

SciTech Connect (OSTI)

We have formulated a transfer matrix method to investigate electronic properties of graphene heterostructure consisting of monolayer graphene and bilayer counterpart. By evaluating transmission, conductance, and band dispersion, we show that, irrespective of the different carrier chiralities in monolayer graphene and bilayer graphene, superlattice consisting of biased bilayer graphene barrier and monolayer graphene well can mimic the electronic properties of conventional semiconductor superlattice, displaying the extended subbands in the quantum tunneling regime and producing anisotropic minigaps for the classically allowed transport. Due to the lateral confinement, the lowest mode has shifted away from the charge neutral point of monolayer graphene component, opening a sizeable gap in concerned structure. Following the gate-field and geometry modulation, all electronic states and gaps between them can be externally engineered in an electric-controllable strategy.

Wang, Yu, E-mail: ywang@semi.ac.cn [Department of Physics, Faculty of Science, Kunming University of Science and Technology, Kunming 650500 (China)

2014-10-28T23:59:59.000Z

111

Boron doping a semiconductor particle  

DOE Patents [OSTI]

A method (10,30) of boron doping a semiconductor particle using boric acid to obtain a p-type doped particle. Either silicon spheres or silicon powder is mixed with a diluted solution of boric acid having a predetermined concentration. The spheres are dried (16), with the boron film then being driven (18) into the sphere. A melt procedure mixes the driven boron uniformly throughout the sphere. In the case of silicon powder, the powder is metered out (38) into piles and melted/fused (40) with an optical furnace. Both processes obtain a p-type doped silicon sphere with desired resistivity. Boric acid is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirements.

Stevens, Gary Don (18912 Ravenglen Ct., Dallas, TX 75287); Reynolds, Jeffrey Scott (703 Horizon, Murphy, TX 75094); Brown, Louanne Kay (2530 Poplar Tr., Garland, TX 75042)

1998-06-09T23:59:59.000Z

112

Vapor deposition of water on graphitic surfaces: Formation of amorphous ice, bilayer ice, ice I, and liquid water  

SciTech Connect (OSTI)

Carbonaceous surfaces are a major source of atmospheric particles and could play an important role in the formation of ice. Here we investigate through molecular simulations the stability, metastability, and molecular pathways of deposition of amorphous ice, bilayer ice, and ice I from water vapor on graphitic and atomless Lennard-Jones surfaces as a function of temperature. We find that bilayer ice is the most stable ice polymorph for small cluster sizes, nevertheless it can grow metastable well above its region of thermodynamic stability. In agreement with experiments, the simulations predict that on increasing temperature the outcome of water deposition is amorphous ice, bilayer ice, ice I, and liquid water. The deposition nucleation of bilayer ice and ice I is preceded by the formation of small liquid clusters, which have two wetting states: bilayer pancake-like (wetting) at small cluster size and droplet-like (non-wetting) at larger cluster size. The wetting state of liquid clusters determines which ice polymorph is nucleated: bilayer ice nucleates from wetting bilayer liquid clusters and ice I from non-wetting liquid clusters. The maximum temperature for nucleation of bilayer ice on flat surfaces, T{sub B}{sup max} is given by the maximum temperature for which liquid water clusters reach the equilibrium melting line of bilayer ice as wetting bilayer clusters. Increasing water-surface attraction stabilizes the pancake-like wetting state of liquid clusters leading to larger T{sub B}{sup max} for the flat non-hydrogen bonding surfaces of this study. The findings of this study should be of relevance for the understanding of ice formation by deposition mode on carbonaceous atmospheric particles, including soot.

Lupi, Laura; Kastelowitz, Noah; Molinero, Valeria, E-mail: Valeria.Molinero@utah.edu [Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850 (United States)

2014-11-14T23:59:59.000Z

113

Metal-doped organic foam  

DOE Patents [OSTI]

Organic foams having a low density and very small cell size and method for producing same in either a metal-loaded or unloaded (nonmetal loaded) form are described. Metal-doped foams are produced by soaking a polymer gel in an aqueous solution of desired metal salt, soaking the gel successively in a solvent series of decreasing polarity to remove water from the gel and replace it with a solvent of lower polarity with each successive solvent in the series being miscible with the solvents on each side and being saturated with the desired metal salt, and removing the last of the solvents from the gel to produce the desired metal-doped foam having desired density cell size, and metal loading. The unloaded or metal-doped foams can be utilized in a variety of applications requiring low density, small cell size foam. For example, rubidium-doped foam made in accordance with the invention has utility in special applications, such as in x-ray lasers.

Rinde, James A. (Livermore, CA)

1982-01-01T23:59:59.000Z

114

Method of doping organic semiconductors  

DOE Patents [OSTI]

A method includes the steps of forming a contiguous semiconducting region and heating the region. The semiconducting region includes polyaromatic molecules. The heating raises the semiconducting region to a temperature above room temperature. The heating is performed in the presence of a dopant gas and the absence of light to form a doped organic semiconducting region.

Kloc, Christian Leo (Constance, DE); Ramirez, Arthur Penn (Summit, NJ); So, Woo-Young (New Providence, NJ)

2012-02-28T23:59:59.000Z

115

Investigation of the effect of bilayer membrane structures and fluctuation amplitudes on SANS/SAXS profile for short membrane wavelength  

SciTech Connect (OSTI)

The effect of bilayer membrane structures and fluctuation amplitudes on small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) profile is investigated based on harmonic motions of the surfactant bilayers with bending as well as thickness fluctuation motions. In this study we consider the case in which the wavelength of the bilayer membrane is shorter than the thickness of the membrane. We find that the thickness of the surfactant bilayer membrane, d{sub m}, affects both q{sub dip} and q{sub peak} of I(q,0) profile, and that the fluctuation amplitude, a, of the membrane changes the peak of I(q,0). A simple formula is derived to estimate the thickness of the bilayer based on the q{sub dip} of the profile obtained from the simulation. The resulting estimates of the thickness of the bilayer with harmonic motion showed accuracy within 1%. Moreover, the bilayer thicknesses estimated from the proposed formula show an excellent agreement with the SANS and SAXS experimental results available in the literatures. We also propose a curve fit model, which describes the relationship between the fluctuation amplitude and the normalized q{sub peak} ratio. The present results show the feasibility of the simple formula to estimate the fluctuation amplitude based on the SANS and SAXS profiles.

Lee, Victor; Hawa, Takumi [School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, Oklahoma 73019 (United States)] [School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, Oklahoma 73019 (United States)

2013-09-28T23:59:59.000Z

116

Evidence for spontaneous interlayer phase coherence in a bilayer quantum Hall exciton condensate  

E-Print Network [OSTI]

double layer 2D electron gas sample. There are several equivalent ways to view the strongly correlatedEvidence for spontaneous interlayer phase coherence in a bilayer quantum Hall exciton condensate J of the excitonic Bose condensate which describes this remarkable quantum Hall state. q 2003 Published by Elsevier

Eisenstein, Jim

117

A Versatile Approach to the Generation of Fluid Supported Lipid Bilayers and Its Applications  

E-Print Network [OSTI]

of transport processes like the conduction of ion channels, the transport of substrate through transmembrane-coating of membrane lipids. Subsequen- tially, transmembrane proteins are incorporated by the fusion of transmembrane proteins in a bilayer and the visualization of the fusion of individual, membrane

118

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

119

Raman spectra of out-of-plane phonons in bilayer graphene  

E-Print Network [OSTI]

The double resonance Raman spectra of the overtone of the out-of-plane tangential optical (oTO) phonon and of combinations of the LO, ZO, and ZA phonons with one another are calculated for bilayer graphene. In the case of ...

Sato, Kentaro

120

Dynamic rupture of polymermetal bilayer plates G.J. McShane a  

E-Print Network [OSTI]

: Bilayers Necking Petalling Underwater blast a b s t r a c t Recent theoretical assessments of metal capacity while the PU1 coating provides no such synergistic effect. The dynamic bulge forming tests blast impulse. Given the ease of apply- ing polyurethane coatings they may provide a practical solution

Fleck, Norman A.

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Direct Visualization of Vesicle-Bilayer Complexes by Atomic Force Microscopy  

E-Print Network [OSTI]

vesicles and bilayers play a central role in cell physiology, enabling secretion, signaling, less is known about the structure and organization of lipids during this process. In addition, the interaction between lipids and proteins is known to be important for fusion. Evidence for this comes from

Kumar, Sanjay

122

NEUTRON SCATTERING SHOWS THAT CYTOCHROME b5 PENETRATES DEEPLY INTO THE LIPID BILAYER  

E-Print Network [OSTI]

NEUTRON SCATTERING SHOWS THAT CYTOCHROME b5 PENETRATES DEEPLY INTO THE LIPID BILAYER E. P. GOGOL to lipid vesicles using neutron small-angle scattering methods. To increase scat- tering contrast between of a highly deuterated phospholipid. Small-angle neutron diffraction patterns were collected in a series of H

123

Magnetization reversal and exchange bias effects in hard/soft ferromagnetic bilayers with orthogonal anisotropies  

E-Print Network [OSTI]

The magnetization reversal processes are discussed for exchange-coupled ferromagnetic hard/soft bilayers made from Co[subscript 0.66]Cr[subscript 0.22]Pt[subscript 0.12] (10 and 20 nm)/Ni (from 0 to 40 nm) films with ...

Ross, Caroline A.

124

Phosphorous doping a semiconductor particle  

DOE Patents [OSTI]

A method (10) of phosphorus doping a semiconductor particle using ammonium phosphate. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried (16, 18), with the phosphorus then being diffused (20) into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement.

Stevens, Gary Don (18912 Ravenglen Ct, Dallas, TX 75287); Reynolds, Jeffrey Scott (703 Horizon, Murphy, TX 75094)

1999-07-20T23:59:59.000Z

125

Mass-related inversion symmetry breaking and phonon self-energy renormalization in isotopically labeled AB-stacked bilayer graphene  

E-Print Network [OSTI]

A mass-related symmetry breaking in isotopically labeled bilayer graphene (2LG) was investigated during in-situ electrochemical charging of AB stacked (AB-2LG) and turbostratic (t-2LG) layers. The overlap of the two ...

Araujo, Paulo Antonio Trinidade

126

Tuning of the spin pumping in yttrium iron garnet/Au bilayer system by fast thermal treatment  

SciTech Connect (OSTI)

In this Letter, we investigated the influence of the fast thermal treatment on the spin pumping in ferromagnetic insulator yttrium iron garnet (YIG)/normal metal Au bilayer system. The YIG/Au bilayer thin films were treated by fast annealing process with different temperatures from 0 to 800?°C. The spin pumping was studied using ferromagnetic resonance. The surface evolution was investigated using a high resolution scanning microscopy and an atomic force microscopy. A strong thermal related spin pumping in YIG/Au bilayer system has been revealed. It was found that the spin pumping process can be enhanced by using fast thermal treatment due to the thermal modifications of the Au surface. The effective spin-mixing conductance of the fast thermal treated YIG/Au bilayer has been obtained.

Jin, Lichuan, E-mail: lichuanj@udel.edu, E-mail: hwzhang@uestc.edu.cn; Zhang, Huaiwu, E-mail: lichuanj@udel.edu, E-mail: hwzhang@uestc.edu.cn; Yang, Qinghui; Tang, Xiaoli; Zhong, Zhiyong [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology, Chengdu 610054 (China); Zhang, Dainan [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Xiao, John Q. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States)

2014-05-07T23:59:59.000Z

127

Indirect heating of Pt by non-equilibrium electrons in Au in a nanoscale Pt/Au bilayer  

E-Print Network [OSTI]

-line equivalent-circuit. For optical exciation of either the Pt or Au side of the bilayer, the majority of energy excitations which are then driven out of thermal equilibrium with the vibrations of the atomic lattice.1

Cahill, David G.

128

Potential commercial application of a bi-layer bone-ligament regeneration scaffold to anterior cruciate ligament replacement  

E-Print Network [OSTI]

A business model was created in order to explore the commercial application of a bi-layer bone-ligament scaffold to the treatment of torn anterior cruciate ligaments (ACL) requiring replacement. The two main keys in producing ...

Li, Jessica C. (Jessica Ching-Yi)

2006-01-01T23:59:59.000Z

129

Lanthanide doped barium phosphorous oxide scintillators  

DOE Patents [OSTI]

The present invention provides for a composition comprising an inorganic scintillator comprising a lanthanide-doped barium phosphorous oxide useful for detecting nuclear material.

Borade, Ramesh B; Bourret-Courchesne, Edith; Denzo, Stephen E

2013-02-26T23:59:59.000Z

130

Lanthanide doped strontium barium mixed halide scintillators  

SciTech Connect (OSTI)

The present invention provides for a composition comprising an inorganic scintillator comprising a lanthanide-doped strontium barium mixed halide useful for detecting nuclear material.

Gundiah, Gautam; Bizarri, Gregory; Hanrahan, Stephen M; Bourret-Courchesne, Edith; Derenzo, Stephen E

2013-07-16T23:59:59.000Z

131

Acid Doped Membranes for High Temperature PEMFC  

Broader source: Energy.gov [DOE]

Presentation on Acid Doped Membranes for High Temperature PEMFC to the High Temperature Membrane Working Group, May 25, 2004 in Philadelphia, PA.

132

Effect of Mn doping on the structural, morphological, optical...  

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

Mn doping on the structural, morphological, optical and magnetic properties of indium tin oxide films. Effect of Mn doping on the structural, morphological, optical and magnetic...

133

Watermelon-like iron nanoparticles: Cr doping effect on magnetism...  

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

Watermelon-like iron nanoparticles: Cr doping effect on magnetism and magnetization interaction reversal. Watermelon-like iron nanoparticles: Cr doping effect on magnetism and...

134

Brillouin light scattering study of spin waves in NiFe/Co exchange spring bilayer films  

SciTech Connect (OSTI)

Spin waves are investigated in Permalloy(Ni{sub 80}Fe{sub 20})/Cobalt(Co) exchange spring bilayer thin films using Brillouin light scattering (BLS) experiment. The magnetic hysteresis loops measured by magneto-optical Kerr effect show a monotonic decrease in coercivity of the bilayer films with increasing Py thickness. BLS study shows two distinct modes, which are modelled as Damon-Eshbach and perpendicular standing wave modes. Linewidths of the frequency peaks are found to increase significantly with decreasing Py layer thickness. Interfacial roughness causes to fluctuate exchange coupling at the nanoscale regimes and the effect is stronger for thinner Py films. A quantitative analysis of the magnon linewidths shows the presence of strong local exchange coupling field which is much larger compared to macroscopic exchange field.

Haldar, Arabinda; Banerjee, Chandrima; Laha, Pinaki; Barman, Anjan, E-mail: abarman@bose.res.in [Thematic Unit of Excellence on Nanodevice Technology, Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata 700098 (India)

2014-04-07T23:59:59.000Z

135

Biaxially aligned buffer layers of cerium oxide, yttria stabilized zirconia, and their bilayers  

SciTech Connect (OSTI)

Biaxially aligned cerium oxide (CeO{sub 2}) and yttria stabilized zirconia (YSZ) films were deposited on Ni-based metal (Hastelloy C276) substrates held at room temperature using ion beam assisted (IBAD) magnetron deposition with the ion beam directed at 55{degree} to the normal of the film plane. In addition, we achieved, room-temperature epitaxial growth of CeO{sub 2} by bias sputtering to form biaxially aligned CeO{sub 2}/YSZ bilayers. The crystalline structure and in-plane orientation of films was investigated by x-ray diffraction techniques. Both the IBAD CeO{sub 2} and YSZ films, and the CeO{sub 2}/YSZ bilayers have a (111) pole in the ion beam direction. {copyright} {ital 1997 American Institute of Physics.}

Gnanarajan, S.; Katsaros, A.; Savvides, N. [CSIRO Telecommunications and Industrial Physics, Lindfield NSW 2070 (Australia)] [CSIRO Telecommunications and Industrial Physics, Lindfield NSW 2070 (Australia)

1997-05-01T23:59:59.000Z

136

Electron dynamics of the buffer layer and bilayer graphene on SiC  

SciTech Connect (OSTI)

Angle- and time-resolved two-photon photoemission (TPPE) was used to investigate electronic states in the buffer layer of 4H-SiC(0001). An image potential state (IPS) series was observed on this strongly surface-bound buffer layer, and dispersion measurements indicated free-electron-like behavior for all states in this series. These results were compared with TPPE taken on bilayer graphene, which also show the existence of a free-electron-like IPS series. Lifetimes for the n?=?2, and n?=?3 states were obtained from time-resolved TPPE; slightly increased lifetimes were observed in the bilayer graphene sample for the n?=?2 the n?=?3 states. Despite the large band gap of graphene at the center of the Brillouin zone, the lifetime results demonstrate that the graphene layers do not behave as a simple tunneling barrier, suggesting that the buffer layer and graphene overlayers play a direct role in the decay of IPS electrons.

Shearer, Alex J.; Caplins, Benjamin W.; Suich, David E.; Harris, Charles B., E-mail: cbharris@berkeley.edu [Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Johns, James E. [Department of Chemistry, University of Minnesota Twin Cities, Minneapolis, Minnesota 55455 (United States); Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

2014-06-09T23:59:59.000Z

137

Bilayer-Spanning DNA Nanopores with Voltage-Switching between Open and Closed State  

E-Print Network [OSTI]

smaller PEGs are assumed to enter the pore. PEG sizing also clarifies that the main ion conducting path runs through the membrane-spanning channel lumen as opposed to any proposed gap between the outer pore wall and the lipid bilayer. At higher voltages... for the development of new DNA nanopores for nanobiotechnology. Building rationally designed nanoscale porous structures that mediate transport across membranes is of general interest in fundamental and applied science.1, 2 Biomimetic engineered nanopores3...

Seifert, Astrid; Göpfrich, Kerstin; Burns, Jonathan R.; Fertig, Niels; Keyser, Ulrich F.; Howorka, Stefan

2014-10-22T23:59:59.000Z

138

Microwave-induced spin currents in ferromagnetic-insulator|normal-metal bilayer system  

SciTech Connect (OSTI)

A microwave technique is employed to simultaneously examine the spin pumping and the spin Seebeck effect processes in a YIG|Pt bilayer system. The experimental results show that for these two processes, the spin current flows in opposite directions. The temporal dynamics of the longitudinal spin Seebeck effect exhibits that the effect depends on the diffusion of bulk thermal-magnons in the thermal gradient in the ferromagnetic-insulator|normal-metal system.

Agrawal, Milan, E-mail: magrawal@physik.uni-kl.de [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany); Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, 67663 Kaiserslautern (Germany); Serga, Alexander A.; Lauer, Viktor; Papaioannou, Evangelos Th.; Hillebrands, Burkard; Vasyuchka, Vitaliy I. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany)

2014-09-01T23:59:59.000Z

139

Dynamic Recompartmentalization of Supported Lipid Bilayers Using Focused Femtosecond Laser Pulses  

E-Print Network [OSTI]

repetition rate of 2.7 kHz at 3 nJ pulse energy for 100 ms produces a dark blurry spot (2 µm fwhm of these applications depend on high peak intensities (>1013 W/cm2) achieved within the focal volume under low-energy Information). The bilayer was maintained wet by sandwiching the sample with a DI water-filled hanging drop

Parikh, Atul N.

140

Quantum Hall Effect In Bilayer Systems And The Noncommutative Plane: A Toy Model Approach  

E-Print Network [OSTI]

We have presented a quantum mechanical toy model for the study of Coulomb interactions in Quantum Hall (QH) system. Inclusion of Coulomb interaction is essential for the study of {\\it{bilayer}} QH system and our model can simulate it, in the compound state, in a perturbative framework. We also show that in the noncommutative plane, the Coulomb interaction is modified at a higher order in the noncommutativity parameter $\\theta$, and only if $\\theta$ varies from layer to layer in the QH system.

B. Basu; Subir Ghosh

2005-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

X-ray small-angle scattering from sputtered CeO{sub 2}/C bilayers  

SciTech Connect (OSTI)

Surface and interface morphology of cerium oxide/carbon bilayers used as thin-film catalysts is studied by grazing-incidence small-angle x-ray scattering, scanning electron microscopy, and atomic-force microscopy, and the dependence of the structural parameters on the thicknesses of the constituting layers is investigated. The applicability of x-ray scattering and its advantages over standard analytical methods are discussed.

Haviar, S.; Dubau, M.; Khalakhan, I.; Vorokhta, M.; Matolinova, I.; Matolin, V. [Department of Surface and Plasma Science, Faculty of Mathematics and Physics Charles University, V Holesovickach 2, 180 00, Prague 8 (Czech Republic); Vales, V.; Endres, J.; Holy, V. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Buljan, M. [Institute Ruder Boskovic, Bijenicka 54, 10000 Zagreb (Croatia); Bernstorff, S. [Sincrotrone ELETTRA, 34149 Basovizza, Trieste (Italy)

2013-01-14T23:59:59.000Z

142

Field Theoretic Study of Bilayer Membrane Fusion III: Membranes with Leaves of Different Composition  

E-Print Network [OSTI]

We extend previous work on homogeneous bilayers to calculate the barriers to fusion of planar bilayers which contain two different amphiphiles, a lamellae-former and a hexagonal former, with different compositions of the twoin each leaf. Self-consistent field theory is employed, and both standard and alternative pathways are explored. We first calculate these barriers as the amount of hexagonal former is increased equally in both leaves to levels appropriate to the plasma membrane of human red blood cells. We follow these barriers as the composition of hexagonal-formers is then increased in the cis layer and decreased in the trans layer, again to an extent comparable to the biological system. We find that, while the fusion pathway exhibits two barriers in both the standard and alternative pathways, in both cases the magnitudes of these barriers are comparable to one another, and small, on the order of 13 kT. As a consequence, one expects that once the bilayers are brought sufficiently close to one another to initiate the process, fusion should occur rapidly.

Jae Youn Lee; Michael Schick

2006-09-20T23:59:59.000Z

143

Interplay between intrinsic and stacking-fault magnetic domains in bi-layered manganites  

SciTech Connect (OSTI)

We present a low temperature X-ray photoemission electron microscopy study of the bi-layered manganite compound La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7} (BL-LSMO) to investigate the influence of stacking faults, which are structurally and magnetically different from the bi-layered host. In BL-LSMO small magnetic moment persists to T* = 300K, well above the Curie temperature of 120K (T{sub C}). Our magnetic images show that 3D stacking faults are responsible for the T* transition. Furthermore, close to the T{sub C}, stacking faults are well coupled to the bi-layered host with latter magnetic domains controlling the spin direction of the stacking faults. Contrary to recent reports, we find that stacking faults do not seed magnetic domains in the host via an exchange spring mechanism and the intrinsic T{sub C} of the BL-LSMO is not lower than 120K.

Hossain, M.A; Burkhardt, Mark H.; Sarkar, S.; Ohldag, H.; Chuang, Y.-D.; Scholl, A.; Young, A.T.; Doran, A.; Dessau, D.S.; Zheng, H.; Mitchell, J.F.; Durr, H.A.; Stohr, J.

2012-09-11T23:59:59.000Z

144

Phase diagram of the CF{sub 4} monolayer and bilayer on graphite  

SciTech Connect (OSTI)

We report an experimental study of physisorbed monolayers and bilayers of CF{sub 4} on graphite using infrared reflection absorption spectroscopy supplemented by ellipsometry. The symmetric C–F stretch mode ?{sub 3} near 1283 cm{sup ?1} in the gas is strongly blue shifted in the film by dynamic dipole coupling. This blue shift provides a very sensitive measure of the inter-molecular spacing in the monolayer and, less directly, in the bilayer. We find that important corrections are necessary to the volumetric coverage scales used in previous heat capacity and x-ray diffraction studies of this system. This requires quantitative and some qualitative changes to the previously proposed phase diagram. We find evidence for a new phase transition in the middle of the hexagonal incommensurate region and construct new phase diagrams in both the variables coverage-temperature and chemical potential-temperature. We determine the compressibility and thermal expansion in the low-pressure hexagonal incommensurate phase and values for the entropy change in several phase transitions. Below about 55 K there is evidence of solution of up to 7% of an impurity, most likely CO, in our monolayer but not the bilayer film.

Thomas, Petros; Hess, George B., E-mail: gbh@virginia.edu [Physics Department, University of Virginia, Charlottesville, Virginia 22904 (United States)

2014-05-21T23:59:59.000Z

145

Doped Carbon Nanotubes for Hydrogen Storage  

E-Print Network [OSTI]

Doped Carbon Nanotubes for Hydrogen Storage U. S. DOE Hydrogen Program Annual Review May, 2003 structure carbon nanotube systems ·Not restricted to physisorption or chemisorption (weak covalent bond structures of doped carbon nanotubes APPROACH Based on C-H bond Dihydrogen bond H H M = + charge = - charge

146

Does water dope carbon nanotubes?  

SciTech Connect (OSTI)

We calculate the long-range perturbation to the electronic charge density of carbon nanotubes (CNTs) as a result of the physisorption of a water molecule. We find that the dominant effect is a charge redistribution in the CNT due to polarisation caused by the dipole moment of the water molecule. The charge redistribution is found to occur over a length-scale greater than 30 Å, highlighting the need for large-scale simulations. By comparing our fully first-principles calculations to ones in which the perturbation due to a water molecule is treated using a classical electrostatic model, we estimate that the charge transfer between CNT and water is negligible (no more than 10{sup ?4}?e per water molecule). We therefore conclude that water does not significantly dope CNTs, a conclusion that is consistent with the poor alignment of the relevant energy levels of the water molecule and CNT. Previous calculations that suggest water n-dopes CNTs are likely due to the misinterpretation of Mulliken charge partitioning in small supercells.

Bell, Robert A.; Payne, Michael C. [Theory of Condensed Matter Group, Cavendish Laboratory, Cambridge (United Kingdom); Mostofi, Arash A. [Department of Materials and Department of Physics, and the Thomas Young Centre for Theory and Simulation of Materials, Imperial College London, London SW7 2AZ (United Kingdom)

2014-10-28T23:59:59.000Z

147

Doping-induced metal-insulator transition in aluminum-doped 4H silicon P. Achatz,1,2,a  

E-Print Network [OSTI]

Doping-induced metal-insulator transition in aluminum-doped 4H silicon carbide P. Achatz,1,2,a J an experimental determination of the doping-induced metal-insulator transition in aluminum-doped 4H silicon concentration lying between 6.4 and 8.7 1020 cm-3 for the metal-insulator transition in these epilayers grown

Paris-Sud XI, Université de

148

Effects of Synthetic Amphiphilic alpha-Helical Peptides on the Electrochemical and Structural Properties of Supported Hybrid Bilayers on Gold  

SciTech Connect (OSTI)

Amphiphilic {alpha}-helices were formed from designed synthetic peptides comprising alanine, phenylalanine, and lysine residues. The insertion of the -helical peptides into hybrid bilayers assembled on gold was studied by a variety of methods to assess the resulting structural characteristics, such as electrical resistance and molecular orientation. Self-assembled monolayers (SAMs) of dodecanethiol (DDT); octadecanethiol (ODT); and 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) were formed on gold substrates with and without incorporated peptide. Supported hybrid bilayers and multilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) were formed on SAMs by the 'paint-freeze' method of bilayer formation. Modeling of electrochemical impedance spectroscopy data using equivalent electrochemical circuits revealed that the addition of peptide decreased dramatically the resistive element of the bilayer films while maintaining the value of the capacitive element, indicating successful incorporation of peptide into a well-formed bilayer. Near-edge X-ray absorption fine structure spectroscopy data provided evidence that the molecules in the SAMs and hybrid multilayers were ordered even in the presence of peptide. The peptide insertion into the SAM was confirmed by observing the {pi}* resonance peak correlating with phenylalanine and a peak in the nitrogen K-edge regime attributable to the peptide bond.

Smith,M.; Tong, J.; Genzer, J.; Fischer, D.; Kilpatrick, P.

2006-01-01T23:59:59.000Z

149

hal-00131838,version1-19Feb2007 Electron states of mono-and bilayer graphene on SiC probed by STM  

E-Print Network [OSTI]

hal-00131838,version1-19Feb2007 Electron states of mono- and bilayer graphene on SiC probed by STM to mono- and bilayer graphene capping a C-rich interface. At low temperature, both terraces show ( 3 × 3 close to the Fermi level. We conclude that the metallic states of the first graphene layer are almost

Paris-Sud XI, Université de

150

Modelling of noble anaesthetic gases and high hydrostatic pressure effects in lipid bilayers  

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

Our objective was to study molecular processes that might be responsible for inert gas narcosis and high-pressure nervous syndrome. The classical molecular dynamics trajectories (200 ns-long) of dioleoylphosphatidylcholine (DOPC) bilayers simulated by the Berger force field were evaluated for water and the atomic distribution of noble gases around DOPC molecules at a pressure range of 1 - 1000 bar and temperature of 310 Kelvin. Xenon and argon have been tested as model gases for general anesthetics, and neon has been investigated for distortions that are potentially responsible for neurological tremor at hyperbaric conditions. The analysis of stacked radial pair distribution functions of DOPC headgroup atoms revealed the explicit solvation potential of gas molecules, which correlates with their dimensions. The orientational dynamics of water molecules at the biomolecular interface should be considered as an influential factor; while excessive solvation effects appearing in the lumen of membrane-embedded ion channels could be a possible cause of inert gas narcosis. All the noble gases tested exhibit similar patterns of the order parameter for both DOPC acyl chains, which is opposite to the patterns found for the order parameter curve at high hydrostatic pressures in intact bilayers. This finding supports the ‘critical volume’ hypothesis of anesthesia pressure reversal. The irregular lipid headgroup-water boundary observed in DOPC bilayers saturated with neon in the pressure range of 1 - 100 bar could be associated with the possible manifestation of neurological tremor at the atomic scale. The non-immobilizer neon also demonstrated the highest momentum impact on the normal component of the DOPC diffusion coefficient representing monolayers undulations rate, which indicates enhanced diffusivity, rather than atom size, as the key factor.

Moskovitz, Yevgeny [Middle Tennessee State University; Yang, Hui [Middle Tennessee State University

2015-01-01T23:59:59.000Z

151

Fast pick up technique for high quality heterostructures of bilayer graphene and hexagonal boron nitride  

SciTech Connect (OSTI)

We present a fast method to fabricate high quality heterostructure devices by picking up crystals of arbitrary sizes. Bilayer graphene is encapsulated with hexagonal boron nitride to demonstrate this approach, showing good electronic quality with mobilities ranging from 17?000 cm{sup 2} V{sup ?1} s{sup ?1} at room temperature to 49?000 cm{sup 2} V{sup ?1} s{sup ?1} at 4.2?K, and entering the quantum Hall regime below 0.5?T. This method provides a strong and useful tool for the fabrication of future high quality layered crystal devices.

Zomer, P. J., E-mail: pj.zomer@gmail.com; Guimarães, M. H. D.; Brant, J. C.; Tombros, N.; Wees, B. J. van [Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Groningen (Netherlands)

2014-07-07T23:59:59.000Z

152

Gates controlled parallel-coupled double quantum dot on both single layer and bilayer graphene  

E-Print Network [OSTI]

Here we report the fabrication and quantum transport measurements of gates controlled parallel-coupled double quantum dot on both bilayer and single layer graphene. It is shown that the interdot coupling strength of the parallel double dots can be effectively tuned from weak to strong regime by both the in-plane plunger gates and back gate. All the relevant energy scales and parameters of the graphene parallel-coupled double dot can be extracted from the honeycomb charge stability diagrams revealed through the transport measurements.

Lin-Jun Wang; Guo-Ping Guo; Da Wei; Gang Cao; Tao Tu; Ming Xiao; Guang-Can Guo; A. M. Chang

2011-04-22T23:59:59.000Z

153

Spin-wave excitation and propagation in microstructured waveguides of yttrium iron garnet/Pt bilayers  

SciTech Connect (OSTI)

We present an experimental study of spin-wave excitation and propagation in microstructured waveguides consisting of a 100?nm thick yttrium iron garnet/platinum (Pt) bilayer. The life time of the spin waves is found to be more than an order of magnitude higher than in comparably sized metallic structures, despite the fact that the Pt capping enhances the Gilbert damping. Utilizing microfocus Brillouin light scattering spectroscopy, we reveal the spin-wave mode structure for different excitation frequencies. An exponential spin-wave amplitude decay length of 31??m is observed which is a significant step towards low damping, insulator based micro-magnonics.

Pirro, P.; Chumak, A. V.; Lägel, B.; Leven, B.; Hillebrands, B. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany)] [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany); Brächer, T. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany) [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany); Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern (Germany); Dubs, C.; Surzhenko, O.; Görnert, P. [Innovent e.V., Prüssingstraße 27B, 07745 Jena (Germany)] [Innovent e.V., Prüssingstraße 27B, 07745 Jena (Germany)

2014-01-06T23:59:59.000Z

154

Monte-Carlo study of the phase transition in the AA-stacked bilayer graphene  

E-Print Network [OSTI]

Tight-binding model of the AA-stacked bilayer graphene with screened electron-electron interactions has been studied using the Hybrid Monte Carlo simulations on the original double-layer hexagonal lattice. Instantaneous screened Coulomb potential is taken into account using Hubbard-Stratonovich transformation. G-type antiferromagnetic ordering has been studied and the phase transition with spontaneous generation of the mass gap has been observed. Dependence of the antiferromagnetic condensate on the on-site electron-electron interaction is examined.

Nikolaev, A A

2014-01-01T23:59:59.000Z

155

Monte-Carlo study of the phase transition in the AA-stacked bilayer graphene  

E-Print Network [OSTI]

Tight-binding model of the AA-stacked bilayer graphene with screened electron-electron interactions has been studied using the Hybrid Monte Carlo simulations on the original double-layer hexagonal lattice. Instantaneous screened Coulomb potential is taken into account using Hubbard-Stratonovich transformation. G-type antiferromagnetic ordering has been studied and the phase transition with spontaneous generation of the mass gap has been observed. Dependence of the antiferromagnetic condensate on the on-site electron-electron interaction is examined.

A. A. Nikolaev; M. V. Ulybyshev

2014-12-04T23:59:59.000Z

156

High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics  

SciTech Connect (OSTI)

High transition temperature superconductor (HTc)/SrTiO{sub 3} (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (? ? 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (?5 × 10{sup ?5} defects/?m{sup 2}). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.

Sirena, M.; Félix, L. Avilés [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina) [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Haberkorn, N. [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)] [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)

2013-07-29T23:59:59.000Z

157

The physics doped Quantum Dimer Models  

E-Print Network [OSTI]

-charge separation ­ Topological defects and holon statistics · Approach based on the Quantum Dimer Model ­ A wide ­ Hole doping: exotic properties of holons #12;3 Collaborators · Arnaud Ralko (Toulouse) · Frédéric Mila superconductor under doping Holon (Q=e, S=0) « spin-charge separation » #12;8 Variational approach of RVB #12

Paris-Sud 11, Université de

158

Distinguishing spin pumping from spin rectification in a Pt/Py bilayer through angle dependent line shape analysis  

SciTech Connect (OSTI)

A pure spin current driven by spin pumping is converted to a DC voltage and detected electrically in a Py/Pt bilayer sample. This DC voltage mixes with a DC voltage produced through spin rectification. The ferromagnetic resonance line shape strongly depends on the microwave magnetic h field distribution. We have systematically studied the line shapes by changing the external magnetic field orientation in plane of a Pt/Py bilayer. A method is demonstrated which allows us to calculate the microwave h field vector distribution, and distinguish spin pumping from spin rectification.

Bai, Lihui; Hyde, P.; Hu, C.-M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg R3T 2N2 (Canada)] [Department of Physics and Astronomy, University of Manitoba, Winnipeg R3T 2N2 (Canada); Feng, Z.; Ding, H. F. [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)] [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

2013-06-17T23:59:59.000Z

159

Electric-field-induced plasmon in AA-stacked bilayer graphene  

SciTech Connect (OSTI)

The collective excitations in AA-stacked bilayer graphene for a perpendicular electric field are investigated analytically within the tight-binding model and the random-phase approximation. Such a field destroys the uniform probability distribution of the four sublattices. This drives a symmetry breaking between the intralayer and interlayer polarization intensities from the intrapair band excitations. A field-induced acoustic plasmon thus emerges in addition to the strongly field-tunable intrinsic acoustic and optical plasmons. At long wavelengths, the three modes show different dispersions and field dependence. The definite physical mechanism of the electrically inducible and tunable mode can be expected to also be present in other AA-stacked few-layer graphenes. -- Highlights: •The analytical derivations are performed by the tight-binding model. •An electric field drives the non-uniformity of the charge distribution. •A symmetry breaking between the intralayer and interlayer polarizations is illustrated. •An extra plasmon emerges besides two intrinsic modes in AA-stacked bilayer graphene. •The mechanism of a field-induced mode is present in AA-stacked few-layer graphenes.

Chuang, Y.C., E-mail: yingchih.chuang@gmail.com; Wu, J.Y., E-mail: yarst5@gmail.com; Lin, M.F., E-mail: mflin@mail.ncku.edu.tw

2013-12-15T23:59:59.000Z

160

Formation and fluidity measurement of supported lipid bilayer on polyvinyl chloride membrane  

SciTech Connect (OSTI)

We prepared an artificial lipid bilayer on a plasticized poly(vinyl chloride) (PVC) membrane on a Si3N4 layer deposited on a Si wafer. We optimized the experimental condition for the fabrication of the PVC membrane, and obtained a PVC membrane with a flat and uniform surface on the scale of several hundreds of micrometer suitable for a substrate for supported lipid bilayers (SLBs). The SLB of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) was formed on the PVC membrane by the vesicle fusion method. The observation with a conventional epi-fluorescence microscope and a confocal laser scanning microscope gave geometrically uniform images of the SLB on the PVC membrane. The fluidity and the mobile fraction of the SLB was evaluated by the fluorescence recovery after photobleaching method, and compared with that on a thermally oxidized SiO{sub 2}/Si substrate. The SLB on the PVC membrane contained immobile fraction ?30%, but the diffusion in the mobile fraction was two times faster than that in the SLB on SiO{sub 2}/Si, which had little immobile fraction.

Kobayashi, Takuji, E-mail: kobayashi-t@int.ee.tut.ac.jp; Kono, Akiteru, E-mail: kobayashi-t@int.ee.tut.ac.jp; Sawada, Kazuaki [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 (Japan); Futagawa, Masato [Department of Electrical and Electronic Information Engineering and Head Office for the Tailor-Made and Baton-Zone Graduate Course, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 (Japan); Tero, Ryugo, E-mail: tero@tut.jp [Electronics-Inspired Interdisciplinary Research Institute and Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 (Japan)

2014-02-20T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Reduced bleaching in organic nanofibers by bilayer polymer/oxide coating  

SciTech Connect (OSTI)

Para-hexaphenylene (p-6P) molecules exhibit a characteristic photoinduced reaction (bleaching) resulting in a decrease in luminescence intensity upon UV light exposure, which could render the technological use of the nanofibers problematic. In order to investigate the photoinduced reaction in nanofibers, optical bleaching experiments have been performed by irradiating both pristine and coated nanofibers with UV light. Oxide coating materials (SiO{sub x} and Al{sub 2}O{sub 3}) were applied onto p-6P nanofibers. These treatments caused a reduction in the bleaching reaction but in addition, the nanofiber luminescence spectrum was significantly altered. It was observed that some polymer coatings [a statistical copolymer of tetrafluoroethylene and 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole, P(TFE-PDD), and poly(methyl methacrylate), PMMA] do not interfere with the luminescence spectrum from the p-6P but are not effective in stopping the bleaching. Bilayer coatings with first a polymer material, which should work as a protection layer to avoid modifications of the p-6P luminescence spectrum, and second an oxide layer used as oxygen blocker were tested and it was found that a particular bilayer polymer/oxide combination results in a significant reduction in bleaching without affecting significantly the emission spectrum from the nanofibers.

Tavares, L.; Kjelstrup-Hansen, J.; Rubahn, H.-G. [NanoSyd, Mads Clausen Institute, University of Southern Denmark, Alsion 2, DK-6400 Soenderborg (Denmark); Sturm, H. [Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin (Germany)

2010-05-15T23:59:59.000Z

162

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

163

Strain and electric field induced electronic properties of two-dimensional hybrid bilayers of transition-metal dichalcogenides  

SciTech Connect (OSTI)

Tunability of the electronic properties of two-dimensional bilayer hetero structures of transition-metal dichalcogenides (i.e., MX{sub 2}-M?X?{sub 2} with (M, M??=?Mo, W; X, X??=?S, Se) is investigated. Application of both strain and electric field is found to modify the band gap and carrier effective mass in the hybrid bilayers considered. The calculated results based on density functional theory suggest that the tensile strain considerably changes the band gap of semiconducting bilayers; it makes the band gap to be indirect, and later initiates the semiconductor-to-metal transition. Application of the external electric fields, on the other hand, shows asymmetric variation in the band gap leading to the closure of the gap at about 0.5–1.0?V/Å. Tuning of the band gap and carrier effective mass in such a controlled manner makes the hybrid bilayers of transition metal dichalcogenides to be promising candidates for application in electronic devices at nanoscale.

Sharma, Munish, E-mail: munishsharmahpu@live.com, E-mail: pk-ahluwalia7@yahoo.com; Kumar, Ashok; Ahluwalia, P. K., E-mail: munishsharmahpu@live.com, E-mail: pk-ahluwalia7@yahoo.com [Department of Physics, Himachal Pradesh University, Shimla 171005 (India); Pandey, Ravindra [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)

2014-08-14T23:59:59.000Z

164

Dye-sensitized solar cells based on a nanoparticle/nanotube bilayer structure and their equivalent circuit analysis  

E-Print Network [OSTI]

Dye-sensitized solar cells based on a nanoparticle/nanotube bilayer structure and their equivalent 2011, Accepted 1st December 2011 DOI: 10.1039/c2nr11617k Dye-sensitized solar cells (DSSCs) were to become an essential component of future global energy production. Dye sensitized solar cells (DSSCs)1

Lin, Zhiqun

165

Elastic free-energy of the edge of an open lipid bilayer based on the interactions of its constituent molecules  

E-Print Network [OSTI]

Lipid-bilayers are the fundamental constituents of the walls of most living cells and lipid vesicles, giving them shape and compartment. The formation and growing of pores in a lipid bilayer have attracted considerable attention from an energetic point of view in recent years. Such pores permit targeted delivery of drugs and genes to the cell, and regulate the concentration of various molecules within the cell. The formation of such pores is caused by various reasons such as changes in cell environment, mechanical stress or thermal fluctuations. Understanding the energy and elastic behaviour of a lipid-bilayer edge is crucial for controlling the formation and growth of such pores. In the present work, the interactions in the molecular level are used to obtain the free energy of the edge of an open lipid bilayer. The resulted free-energy density includes terms associated with flexural and torsional energies of the edge, in addition to a line-tension contribution. The line tension, elastic moduli, and spontaneous normal and geodesic curvatures of the edge are obtained as functions of molecular distribution, molecular dimensions, cutoff distance, and the interaction strength. These parameters are further analyzed by implementing a soft-core interaction potential in the microphysical model. The dependence of the elastic free-energy of the edge to the size of the pore is reinvestigated through an illustrative example, and the results are found to be in agreement with the previous observations.

Meisam Asgari; Aisa Biria

2015-02-17T23:59:59.000Z

166

Structure, Magnetism and Conductivity in Epitaxial Ti-doped ...  

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

Magnetism and Conductivity in Epitaxial Ti-doped -Fe2O3 Hematite: Experiment and density functional theory Structure, Magnetism and Conductivity in Epitaxial Ti-doped -Fe2O3...

167

First Principles Prediction of Nitrogen-doped Carbon Nanotubes...  

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

First Principles Prediction of Nitrogen-doped Carbon Nanotubes as a High-Performance Cathode for Li-S Batteries. First Principles Prediction of Nitrogen-doped Carbon Nanotubes as a...

168

Conductivity of Oriented Samaria-Doped Ceria Thin Films Grown...  

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

Conductivity of Oriented Samaria-Doped Ceria Thin Films Grown by Oxygen-plasma-assisted Molecular Beam Epitaxy. Conductivity of Oriented Samaria-Doped Ceria Thin Films Grown by...

169

Metal-doped organic gels and method thereof  

DOE Patents [OSTI]

Disclosed herein is a sol-gel polymerization process for synthesizing metal-doped organic gels. The process polymerizes metal salts of hydroxylated benzenes or hydroxylated benzene derivatives with alkyl or aryl aldehydes to form metal-doped, wet, organic gels. The gels can then be dried by supercritical solvent extraction to form metal-doped aerogels or by evaporation to form metal-doped xerogels. The aerogels and xerogels can then be pyrolyzed.

Satcher, Jr., Joe H. (Patterson, CA); Baumann, Theodore F. (Tracy, CA)

2007-10-23T23:59:59.000Z

170

Charge neutrality in heavily doped emitters Jesus A. del Alamo  

E-Print Network [OSTI]

of a typical solar-cell emitter, being particularly excellent in the heavily doped regions beneath the surface

del Alamo, Jesús A.

171

Metal-doped organic gels and method thereof  

SciTech Connect (OSTI)

Disclosed herein is a sol-gel polymerization process for synthesizing metal-doped organic gels. The process polymerizes metal salts of hydroxylated benzenes or hydroxylated benzene derivatives with alkyl or aryl aldehydes to form metal-doped, wet, organic gels. The gels can then be dried by supercritical solvent extraction to form metal-doped aerogels or by evaporation to form metal-doped xerogels. The aerogels and xerogels can then be pyrolyzed.

Satcher Jr., Joe H.; Baumann, Theodore F.

2003-09-02T23:59:59.000Z

172

Doped luminescent materials and particle discrimination using same  

DOE Patents [OSTI]

Doped luminescent materials are provided for converting excited triplet states to radiative hybrid states. The doped materials may be used to conduct pulse shape discrimination (PSD) using luminescence generated by harvested excited triplet states. The doped materials may also be used to detect particles using spectral shape discrimination (SSD).

Doty, F. Patrick; Allendorf, Mark D; Feng, Patrick L

2014-10-07T23:59:59.000Z

173

Compact, stable 1 ghz femtosecond er-doped fiber lasers  

E-Print Network [OSTI]

We demonstrate a high-repetition-rate soliton fiber laser that is based on highly-doped anomalously-dispersive erbium-doped fiber. By splicing an 11-mm single mode fiber to the erbium-doped fiber, thermal damage of the ...

Byun, Hyunil

174

RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS  

E-Print Network [OSTI]

RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS PART I: ALLENE Full-length article SHORTENED RUNNING TITLE : METHANE FLAMES DOPED BY ALLENE OR PROPYNE * E investigated: a pure methane flame and two methane flames doped by allene and propyne, respectively. The gases

Paris-Sud XI, Université de

175

RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS  

E-Print Network [OSTI]

RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS PART II: 1,3-BUTADIENE-length article SHORTENED RUNNING TITLE : METHANE FLAMES DOPED BY 1,3-BUTADIENE * E-mail : Pierre of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been

Paris-Sud XI, Université de

176

Novel Approach to Conformal FINFET Extension Doping  

SciTech Connect (OSTI)

This paper presents a novel strategy to achieve conformal FINFET extension doping with low tilt-angle beam-line ion implantation. The process relies on the self-aligned cap layer formation exclusively on top of the FIN to tune doping levels in this particular area by partial dopant trapping. The conformality itself is evaluated for n- and p-type dopants by a novel extraction method applied to FIN resistor test structures. Furthermore, the process was integrated into a full NMOS device flow and compared to a highly tilted and more conformal As implant condition.

Zschaetzsch, G.; Vandervorst, W. [imec Kapeldreef 75, B-3001 Leuven (Belgium); Hoffmann, T. Y.; Horiguchi, N. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, B-3001 Leuven (Belgium); Hautala, J.; Shao, Y. [TEL Epion Inc., 37 Manning Road, Billerica, MA, 01821 (United States)

2011-01-07T23:59:59.000Z

177

Phenomenological model for a novel melt-freeze phase of sliding bilayers  

E-Print Network [OSTI]

Simulations show that sliding bilayers of colloidal particles can exhibit a new phase, the ``melt-freeze'' phase, where the layers stochastically alternate between solidlike and liquidlike states. We introduce a mean field phenomenological model with two order parameters to understand the interplay of two adjacent layers while the system is in this remarkable phase. Predictions from our numerical simulations of a system in the melt-freeze phase include the tendency of two adjacent layers to be in opposite states (solid and liquid) and the difference between the fluctuation of the order parameter in one layer while the other layer is in the same phase compared to the fluctuation while the other layer is in the opposite phase. We expect this behavior to be seen in future simulations and experiments.

Trieu Mai

2006-01-31T23:59:59.000Z

178

Visualization of Domain Formation in the Inner and Outer Leaflets of a Phospholipid Bilayer  

E-Print Network [OSTI]

Abstract. Large vesicles (5-10-~tm in diameter) were formed in the presence of phospholipids fluorescently labeled on the acyl chain and visualized using a fluorescence microscope, charge-coupled-device camera and digital image processor. When such vesicles contained a fluorescent phosphatidic acid (PA) and were exposed to 2 mM CaC12 or 0.5 mM PrCI3, it was possible to visualize PA-enriched domains within the vesicles. Calcium-induced domain formation was reversible in the presence of 4 mM EGTA. Vesicles were formed containing fluorescent PA on either the inner or outer leaflet of the bilayer and the patching and dissolution of patching were studied under conditions where calcium was present on the outside of the vesicle and where calcium was distributed across the

Doris M. Haverstick; Michael Glaser

179

Does fluoride disrupt hydrogen bond network in cationic lipid bilayer? Time-dependent fluorescence shift of Laurdan and molecular dynamics simulations  

SciTech Connect (OSTI)

Time-dependent fluorescence shift (TDFS) of Laurdan embedded in phospholipid bilayers reports on hydration and mobility of the phospholipid acylgroups. Exchange of H{sub 2}O with D{sub 2}O prolongs the lifetime of lipid-water and lipid-water-lipid interactions, which is reflected in a significantly slower TDFS kinetics. Combining TDFS measurements in H{sub 2}O and D{sub 2}O hydrated bilayers with atomistic molecular dynamics (MD) simulations provides a unique tool for characterization of the hydrogen bonding at the acylgroup level of lipid bilayers. In this work, we use this approach to study the influence of fluoride anions on the properties of cationic bilayers composed of trimethylammonium-propane (DOTAP). The results obtained for DOTAP are confronted with those for neutral phosphatidylcholine (DOPC) bilayers. Both in DOTAP and DOPC H{sub 2}O/D{sub 2}O exchange prolongs hydrogen-bonding lifetime and does not disturb bilayer structure. These results are confirmed by MD simulations. TDFS experiments show, however, that for DOTAP this effect is cancelled in the presence of fluoride ions. We interpret these results as evidence that strongly hydrated fluoride is able to steal water molecules that bridge lipid carbonyls. Consequently, when attracted to DOTAP bilayer, fluoride disrupts the local hydrogen-bonding network, and the differences in TDFS kinetics between H{sub 2}O and D{sub 2}O hydrated bilayers are no longer observed. A distinct behavior of fluoride is also evidenced by MD simulations, which show different lipid-ion binding for Cl{sup ?} and F{sup ?}.

Pokorna, Sarka; Jurkiewicz, Piotr; Hof, Martin, E-mail: martin.hof@jh-inst.cas.cz [J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8 (Czech Republic); Vazdar, Mario [Division of Organic Chemistry and Biochemistry, Rudjer Boškovi? Institute, P.O.B. 180, HR-10002 Zagreb (Croatia); Cwiklik, Lukasz [J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8 (Czech Republic); Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic); Jungwirth, Pavel [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic); Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland)

2014-12-14T23:59:59.000Z

180

Self-activating and doped tantalate phosphors.  

SciTech Connect (OSTI)

An ideal red phosphor for blue LEDs is one of the biggest challenges for the solid-state lighting industry. The appropriate phosphor material should have good adsorption and emission properties, good thermal and chemical stability, minimal thermal quenching, high quantum yield, and is preferably inexpensive and easy to fabricate. Tantalates possess many of these criteria, and lithium lanthanum tantalate materials warrant thorough investigation. In this study, we investigated red luminescence of two lithium lanthanum tantalates via three mechanisms: (1) Eu-doping, (2) Mn-doping and (3) self-activation of the tantalum polyhedra. Of these three mechanisms, Mn-doping proved to be the most promising. These materials exhibit two very broad adsorption peaks; one in the UV and one in the blue region of the spectrum; both can be exploited in LED applications. Furthermore, Mn-doping can be accomplished in two ways; ion-exchange and direct solid-state synthesis. One of the two lithium lanthanum tantalate phases investigated proved to be a superior host for Mn-luminescence, suggesting the crystal chemistry of the host lattice is important.

Nyman, May Devan; Rohwer, Lauren Elizabeth Shea

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Photoregulated potassium ion permeation through dihexadecyl phosphate bilayers containing azobenzene and stilbene surfactants  

SciTech Connect (OSTI)

Photoresponsive asymmetrically organized systems based upon small unilamellar dihexadecyl phosphate (DHP) vehicles were constructed by entrapping high concentrations of potassium ion within the vesicular aqueous core and incorporating either an amphiphilic trans-azobenzene-containing phosphate monoester or an amphiphilic trans-stilbene-containing carboxylic acid into its membrane structure. Spectroscopic measurements indicated that the azobenzene derivative was molecularly dispersed in the hydrocarbon phase of the vesicle and that the extent of aggregation of the membrane-localized stilbene derivative was minor. Thermal K{sup +} leak rates from the doped vesicles were very low, with calculated permeability coefficients (P) of {approximately}4 {times} 10{sup {minus}12} cm/s at 40 C for DHP vesicles containing 5.5 mol % of the trans-azobenzene derivative and {approximately}1.5 {times} 10{sup {minus}11} cm/s at 38 C for vesicles containing 5.5 mol % of the trans-stilbene derivative; for comparison, P {approx_equal} 2 {times} 10{sup {minus}12} cm/s for undoped vesicles at 40 C. Photoexcitation of the azobenzene-doped vesicles at 360 nm caused >90% trans {r_arrow} cis photoisomerization over the measured temperature range (25--40 C), with complete reversion to the trans isomer upon photoexcitation at 450 nm. Photoexcitation of deoxygenated suspensions of the stilbene-doped vesicles at 315 nm gave {approximately}80% conversion to the cis isomer in the photostationary state, which was not reversible. At 25 C, K{sup +} leak rates for the isomeric azobenzene-doped vesicles were nearly identical; at 40 C, K{sup +} leakage for the DHP vesicles containing the cis-azobenzene isomer corresponded to P {approx_equal} 2 {times} 10{sup {minus}11} cm/s, 5-fold greater than that of the trans isomer. In trans {r_arrow} cis {r_arrow} trans photocycling experiments, K{sup +} leak rates alternately increased and decreased, indicating that the vesicles remained intact. At 40 C, K{sup +} leakage from the vesicles containing predominantly cis-stilbene was {approximately}2-fold greater than that from vesicles with the corresponding trans isomer. In electrochemical experiments, viologen-mediated reduction of the DHP-bound trans-azobenzene occurred at E < {minus}0.44 V, with hydrazobenzene reoxidation at E {approx_equal} {minus}0.16 V; addition of viologen radicals to aqueous suspensions of the trans-azobenzene-doped DHP vesicles caused immediate decolorization of the dye.

Lei, Y.; Hurst, J.K. [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry] [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry

1999-05-11T23:59:59.000Z

182

Geometry of hydrogen bonds formed by lipid bilayer nitroxide probes : A high frequency pulsed ENDOR/EPR study.  

SciTech Connect (OSTI)

Solvent effects on magnetic parameters of nitroxide spin labels in combination with side-directed spin-labeling EPR methods provide very useful means for elucidating polarity profiles in lipid bilayers and mapping local electrostatic effects in complex biomolecular systems. One major contributor to these solvent effects is the hydrogen bonds that could be formed between the nitroxide moiety and water and/or the available hydroxyl groups. Here, formation of hydrogen bonds between a lipid bilayer spin probe 5-doxyl stearic acid, 5DSA and hydrogen-bond donors has been studied using high-frequency (HF) pulsed ENDOR and EPR. A hydrogen-bonded deuteron was directly detected in HF ENDOR (130 GHz) spectra of 5DSA dissolved in several deuterated alcohols, while the characteristic signal was absent in nonpolar toluene-d{sub 8}. The length of the hydrogen bond, 1.74 {+-} 0.06 {angstrom}, and its geometry were found to be essentially the same for all four alcohols studied, indicating that nearly identical hydrogen bonds have been formed regardless of the solvent dielectric constant. This strengthens a hypothesis that HF EPR spectra are exclusively sensitive to formation of hydrogen bonds and could be used for probing the hydrogen-bond network in complex biomolecular assemblies and lipid bilayers with site-directed spin-labeling methods.

Smirnova, T. I.; Smirnov, A. I.; Pachtchenko, S.; Poluektov, O. G.; Chemistry; North Carolina State Univ.

2007-01-01T23:59:59.000Z

183

Cat-doping: Novel method for phosphorus and boron shallow doping in crystalline silicon at 80?°C  

SciTech Connect (OSTI)

Phosphorus (P) or boron (B) atoms can be doped at temperatures as low as 80 to 350?°C, when crystalline silicon (c-Si) is exposed only for a few minutes to species generated by catalytic cracking reaction of phosphine (PH{sub 3}) or diborane (B{sub 2}H{sub 6}) with heated tungsten (W) catalyzer. This paper is to investigate systematically this novel doping method, “Cat-doping”, in detail. The electrical properties of P or B doped layers are studied by the Van der Pauw method based on the Hall effects measurement. The profiles of P or B atoms in c-Si are observed by secondary ion mass spectrometry mainly from back side of samples to eliminate knock-on effects. It is confirmed that the surface of p-type c-Si is converted to n-type by P Cat-doping at 80?°C, and similarly, that of n-type c-Si is to p-type by B Cat-doping. The doping depth is as shallow as 5?nm or less and the electrically activated doping concentration is 10{sup 18} to 10{sup 19?}cm{sup -3} for both P and B doping. It is also found that the surface potential of c-Si is controlled by the shallow Cat-doping and that the surface recombination velocity of minority carriers in c-Si can be enormously lowered by this potential control.

Matsumura, Hideki; Hayakawa, Taro; Ohta, Tatsunori; Nakashima, Yuki; Miyamoto, Motoharu; Thi, Trinh Cham; Koyama, Koichi; Ohdaira, Keisuke [Japan Advanced Institute of Science and Technology (JAIST), Asahidai, Nomi-shi, Ishikawa-ken 923-1292 (Japan)

2014-09-21T23:59:59.000Z

184

Initial reactions in Ti{endash}Si bilayers: New indications from in situ measurements  

SciTech Connect (OSTI)

The interactions occurring in a Ti{endash}Si bilayer have been investigated by in situ resistance measurements and the reaction products have been analyzed by complementary techniques, such as x-ray diffraction, Auger electron spectroscopy, and MeV {sup 4}He{sup +} Rutherford backscattering. The measurements were performed by heating the samples at a constant rate in the 5{endash}425{degree}C/min range. The samples are 60 nm of titanium sputter deposited on 250 nm of a silicon film deposited by chemical vapor technique; the bilayers were placed on 650 nm of SiO{sub 2}, thermally grown on p-type {l_angle}100{r_angle} silicon wafers. Samples were also prepared by reactively depositing 25 nm of TiN on the Ti film. The TiN cap, deposited without breaking the vacuum, protects the metal films from contaminants, namely oxygen, during handling and heat treatments. It has been shown that, at temperatures around 400{degree}C and before any massive Ti{endash}Si interaction, the resistance increases. This effect, attributed in the literature to the silicon diffusion in the metal film, is due to oxygen, generally contained in the annealing ambient, which diffuses in the Ti film. The Ti{endash}Si reaction produces a decrease in the value of resistance; the first decrease, generally attributed to the formation of a C49{endash}TiSi{sub 2} phase, is due to the growth of an amorphous compound having a graded in-depth composition between Ti{sub 5}Si{sub 3} and TiSi. The activation energy for such formation is 2.8{+-}0.1 eV. At higher temperatures C49{endash}TiSi{sub 2} starts to form, more likely between the silicon and the amorphous layer. The formation of silicide induces a segregation of oxygen in the unreacted Ti film, thus slowing down the growth of silicide. {copyright} 2001 American Institute of Physics.

Cocchi, R.; Giubertoni, D.; Ottaviani, G.; Marangon, T.; Mastracchio, G.; Queirolo, G.; Sabbadini, A.

2001-06-01T23:59:59.000Z

185

Substrate and method for the formation of continuous magnesium diboride and doped magnesium diboride wire  

DOE Patents [OSTI]

A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.

Suplinskas, Raymond J. (Haverhill, MA); Finnemore, Douglas (Ames, IA); Bud'ko, Serquei (Ames, IA); Canfield, Paul (Ames, IA)

2007-11-13T23:59:59.000Z

186

Tungsten-doped thin film materials  

DOE Patents [OSTI]

A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

2003-12-09T23:59:59.000Z

187

Combustion Synthesis of Doped Thermoelectric Oxides  

SciTech Connect (OSTI)

Self-propagating high-temperature synthesis (SHS) was used to prepare silver doped calcium cobaltates (Ca1.24- xAgxCo1.62O3.86, x = 0.03 - 0.12) powders. SHS is a simple and economic process to synthesize ceramic materials with minimum energy requirements. The heat generated by the SHS reaction can sustain the propagation of the reaction front and convert reactants to desired products. The effect of doping level on thermoelectric properties was investigated in this study. Results show the substitution of calcium by silver decreases the thermal conductivity significantly. XRD and surface area measurements show synthesized powders are phase pure and have large specific surface areas.

Selig, Jiri [Lamar University; Lin, Sidney [Lamar University; Lin, Hua-Tay [ORNL; Johnson, D Ray [ORNL

2012-01-01T23:59:59.000Z

188

Influence of Si Co-doping on electrical transport properties of magnesium-doped boron nanoswords  

SciTech Connect (OSTI)

Magnesium-doped boron nanoswords were synthesized via a thermoreduction method. The as-prepared nanoswords are single crystalline and {beta}-rhombohedral ({beta}-rh) phase. Electrical transport measurements show that variable range hopping conductivity increases with temperature, and carrier mobility has a greater influence than carrier concentration. These results are consistent with the three dimensional Mott's model (M. Cutler and N. F. Mott, Phys. Rev. 181, 1336 (1969)) besides a high density of localized states at the Fermi level compared with bulk {beta}-rh boron. Conductivity of Mg-doped boron nanoswords is significantly lower than that of ''pure'' (free of magnesium) boron nanoswords. Electron energy loss spectroscopy studies confirm that the poorer conductivity arises from silicon against magnesium doping.

Tian Yuan; Lu Hongliang; Tian Jifa; Li Chen; Hui Chao; Shi Xuezhao; Huang Yuan; Shen Chengmin; Gao Hongjun [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2012-03-05T23:59:59.000Z

189

Electrical and optical properties of gadolinium doped bismuth ferrite nanoparticles  

SciTech Connect (OSTI)

Multiferroic bismuth ferrite (BFO) and gadolinium (Gd) doped bismuth ferrite had been synthesized by a sol-gel method. Particle size had been estimated by Transmission electron microscopy (TEM) and found to decrease with Gd doping. We studied the temperature and frequency dependence of impedance and electric modulus and calculated the grain and grain boundary resistance and capacitance of the investigated samples. We observed that electrical activation energy increases for all the doped samples. Optical band gap also increases for the doped samples which can be used in photocatalytic application of BFO.

Mukherjee, A., E-mail: soumen.basu@phy.nitdgp.ac.in; Banerjee, M., E-mail: soumen.basu@phy.nitdgp.ac.in; Basu, S., E-mail: soumen.basu@phy.nitdgp.ac.in [Department of Physics, National Institute of Technology, Durgapur-713209 (India); Pal, M. [CSIR-Central Mechanical Engineering Research Institute, Durgapur-713209 (India)

2014-04-24T23:59:59.000Z

190

Boron-doped superlattices and Bragg mirrors in diamond  

SciTech Connect (OSTI)

A periodic modulation of the boron doping level of single crystal diamond multilayers over more than three orders of magnitude during epitaxial growth by microwave plasma-enhanced chemical vapor deposition is shown to yield Bragg mirrors in the visible. The thicknesses and doping level of the individual layers were controlled by in situ spectroscopic ellipsometry, enabling to tune the reflectance peak to the wavelength range of diamond color centers, such as NV{sup 0} or NV{sup ?}. The crystalline quality, periodicity, and sharpness of the doping transitions in these doping superlattices over tens of periods were confirmed by high resolution X-ray diffraction.

Fiori, A. [University of Grenoble Alpes, Inst. NEEL, 38042 Grenoble (France); CNRS, Inst. NEEL, 25 rue des Martyrs, 38042 Grenoble (France); National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Bousquet, J.; Eon, D.; Omnès, F.; Bustarret, E., E-mail: Etienne.bustarret@neel.cnrs.fr [University of Grenoble Alpes, Inst. NEEL, 38042 Grenoble (France); CNRS, Inst. NEEL, 25 rue des Martyrs, 38042 Grenoble (France); Bellet-Amalric, E. [University of Grenoble Alpes, Inst. NEEL, 38042 Grenoble (France); CEA-Grenoble, INAC/SP2M, 17 rue des Martyrs, 38054 Grenoble (France)

2014-08-25T23:59:59.000Z

191

A new class of high ZT doped bulk nanothermoelectrics through...  

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

through impurity doping and nanostructuring ramanath.pdf More Documents & Publications Nano-structures Thermoelectric Materals - Part 1 The Bottom-Up Approach forThermoelectric...

192

Field Theoretic Study of Bilayer Membrane Fusion: II. Mechanism of a Stalk-Hole Complex  

E-Print Network [OSTI]

We use self-consistent field theory to determine structural and energetic properties of intermediates and transition states involved in bilayer membrane fusion. In particular, we extend our original calculations from those of the standard hemifusion mechanism, which was studied in detail in the first paper of this series, to consider a possible alternative to it. This mechanism involves non-axial stalk expansion, in contrast to the axially symmetric evolution postulated in the classical mechanism. Elongation of the initial stalk facilitates the nucleation of holes and leads to destabilization of the fusing membranes via the formation of a stalk-hole complex. We study properties of this complex in detail, and show how transient leakage during fusion, previously predicted and recently observed in experiment, should vary with system architecture and tension. We also show that the barrier to fusion in the alternative mechanism is lower than that of the standard mechanism by a few $k_BT$ over most of the relevant region of system parameters, so that this alternative mechanism is a viable alternative to the standard pathway.

Kirill Katsov; Marcus Mueller; Michael Schick

2005-07-19T23:59:59.000Z

193

Sandwich beam model for free vibration analysis of bilayer graphene nanoribbons with interlayer shear effect  

SciTech Connect (OSTI)

In this study, sandwich beam model (SM) is proposed for free vibration analysis of bilayer graphene nanoribbons (BLGNRs) with interlayer shear effect. This model also takes into account the intralayer (in-plane) stretch of graphene nanoribbons. The molecular dynamics (MD) simulations using the software LAMMPS and Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potential are done to validate the accuracy of the sandwich model results. The MD simulation results include the two first frequencies of cantilever BLGNRs with different lengths and two interlayer shear moduli, i.e., 0.25 and 4.6?GPa. These two interlayer shear moduli, 0.25 and 4.6?GPa, can be obtained by sliding a small flake of graphene on a large graphene substrate when the parameter of E-LJ term in AIREBO potential, epsilon-CC, is set to be 2.84 and 45.44?meV, respectively. The SM results for a wide range of bending rigidity values show that the proposed model, i.e., the SM, predicts much better than the previous beam model in which the intralayer stretch is ignored. In addition, it is observed that the model can properly predict the natural frequencies of BLGNRs for various values of the bending rigidity and the interlayer shear modulus.

Nazemnezhad, Reza, E-mail: rnazemnezhad@iust.ac.ir, E-mail: rnazemnezhad@du.ac.ir [School of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Shokrollahi, Hassan [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Hosseini-Hashemi, Shahrokh [School of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Center of Excellence in Railway Transportation, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)

2014-05-07T23:59:59.000Z

194

Coexistence and competition of nematic and gapped states in bilayer graphene  

E-Print Network [OSTI]

In bilayer graphene, the phase diagram in the plane of a strain-induced bare nematic term, ${\\cal N}_{0}$, and a top-bottom gates voltage imbalance, $U_{0}$, is obtained by solving the gap equation in the random-phase approximation. At nonzero ${\\cal N}_0$ and $U_0$, the phase diagram consists of two hybrid spin-valley symmetry-broken phases with both nontrivial nematic and mass-type order parameters. The corresponding phases are separated by a critical line of first- and second-order phase transitions at small and large values of ${\\cal N}_0$, respectively. The existence of a critical end point, where the line of first-order phase transitions terminates, is predicted. For ${\\cal N}_0=0$, a pure gapped state with a broken spin-valley symmetry is the ground state of the system. As ${\\cal N}_{0}$ increases, the nematic order parameter increases, and the gap weakens in the hybrid state. For $U_{0}=0$, a quantum second-order phase transition from the hybrid state into a pure gapless nematic state occurs when the strain reaches a critical value. A nonzero $U_{0}$ suppresses the critical value of the strain. The relevance of these results to recent experiments is briefly discussed.

E. V. Gorbar; V. P. Gusynin; V. A. Miransky; I. A. Shovkovy

2012-09-24T23:59:59.000Z

195

Asymmetric Electron Transport at Monolayer-Bilayer Heterojunctions of Epitaxial Graphene  

SciTech Connect (OSTI)

The symmetry of the graphene honeycomb lattice is a key element determining many of graphene s unique electronic properties, such as the linear energy-momentum dispersion and the suppressed backscattering 1,2. However, line defects in large-scale epitaxial graphene films, such as grain boundaries, edges, surface steps, and changes in layer thickness, often break the sublatttice symmetry and can impact transport properties of graphene profoundly 3-6. Here we report asymmetric electron transport upon polarity reversal at individual monolayer-bilayer (ML-BL) boundaries in epitaxial graphene on SiC (0001), revealed by scanning tunneling potentiometry. A greater voltage drop is observed when the current flows from BL to ML graphene than in the reverse direction, and the difference remains nearly unchanged with increasing current. This is not a typical nonlinear conductance due to electron transmission through an asymmetric potential. Rather, it indicates the opening of a dynamic energy gap at the Fermi energy due to the Coulomb interaction between the injected nonequilibrium electron density and the pseudospin polarized Friedel oscillation charge density at the boundary. This intriguing heterojunction transport behavior opens a new avenue towards novel quantum functions such as quantum switching.

Li, An-Ping [ORNL] [ORNL; Clark, Kendal W [ORNL] [ORNL; Zhang, Xiaoguang [ORNL] [ORNL; Gu, Gong [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); He, Guowei [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU)

2014-01-01T23:59:59.000Z

196

Quantum radiations from exciton condensate in Electron-Hole Bilayer Systems  

E-Print Network [OSTI]

Superfluid has been realized in Helium-4, Helium-3 and ultra-cold atoms. It has been widely used in making high-precision devices and also in cooling various systems. There have been extensive experimental search for possible exciton superfluid (ESF) in semiconductor electron-hole bilayer (EHBL) systems below liquid Helium temperature. However, exciton superfluid are meta-stable and will eventually decay through emitting photons. Here we study quantum nature of photons emitted from the excitonic superfluid (ESF) phase in the semiconductor EHBL and find that the light emitted from the excitonic superfluid has unique and unusual features not shared by any other atomic or condensed matter systems. We show that the emitted photons along the direction perpendicular to the layer are in a coherent state, those along all tilted directions are in a two modes squeezed state. We determine the two mode squeezing spectra, the angle resolved power spectrum, the line shapes of both the momentum distribution curve (MDC) and the energy distribution curve (EDC). From the two photon correlation functions, we find there are photon bunching, the photo-count statistics is super-Poissonian. We discuss how several important parameters such as the chemical potential, the exciton decay rate, the quasiparticle energy spectrum and the dipole-dipole interaction strength between the excitons in our theory can be extracted from the experimental data and comment on available experimental data on both EDC and MDC.

Jinwu Ye; T. Shi; Longhua Jiang; C. P. Sun

2008-02-07T23:59:59.000Z

197

Soft X-Ray Spectroscopic Study of Dense Strontium-Doped Lanthanum...  

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

Spectroscopic Study of Dense Strontium-Doped Lanthanum Manganite Cathodes for Solid Oxide Fuel Cell Applications. Soft X-Ray Spectroscopic Study of Dense Strontium-Doped Lanthanum...

198

In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous...  

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

Synthesis of Hierarchical Nitrogen-Doped Porous Carbon for High Performance Supercapacitors. In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous Carbon for High...

199

Spectral Control of Emission from Tin Doped Targets for Extreme Ultraviolet Lithography  

E-Print Network [OSTI]

control of emissions from tin doped targets for extremearray (UTA) emission around 13.5 nm from solid density tinand tin doped foam targets. Extreme ultraviolet (EUV)

2006-01-01T23:59:59.000Z

200

Dye-Doped Silica Nanoparticle Labels/Protein Microarray for Detection...  

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

Dye-Doped Silica Nanoparticle LabelsProtein Microarray for Detection of Protein Biomarkers. Dye-Doped Silica Nanoparticle LabelsProtein Microarray for Detection of Protein...

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.


201

Single Ion Implantation and Deterministic Doping  

SciTech Connect (OSTI)

The presence of single atoms, e.g. dopant atoms, in sub-100 nm scale electronic devices can affect the device characteristics, such as the threshold voltage of transistors, or the sub-threshold currents. Fluctuations of the number of dopant atoms thus poses a complication for transistor scaling. In a complementary view, new opportunities emerge when novel functionality can be implemented in devices deterministically doped with single atoms. The grand price of the latter might be a large scale quantum computer, where quantum bits (qubits) are encoded e.g. in the spin states of electrons and nuclei of single dopant atoms in silicon, or in color centers in diamond. Both the possible detrimental effects of dopant fluctuations and single atom device ideas motivate the development of reliable single atom doping techniques which are the subject of this chapter. Single atom doping can be approached with top down and bottom up techniques. Top down refers to the placement of dopant atoms into a more or less structured matrix environment, like a transistor in silicon. Bottom up refers to approaches to introduce single dopant atoms during the growth of the host matrix e.g. by directed self-assembly and scanning probe assisted lithography. Bottom up approaches are discussed in Chapter XYZ. Since the late 1960's, ion implantation has been a widely used technique to introduce dopant atoms into silicon and other materials in order to modify their electronic properties. It works particularly well in silicon since the damage to the crystal lattice that is induced by ion implantation can be repaired by thermal annealing. In addition, the introduced dopant atoms can be incorporated with high efficiency into lattice position in the silicon host crystal which makes them electrically active. This is not the case for e.g. diamond, which makes ion implantation doping to engineer the electrical properties of diamond, especially for n-type doping much harder then for silicon. Ion implantation is usually a highly statistical process, where high fluences of energetic ions, ranging from {approx}10{sup 9} to >10{sup 16} cm{sup -2} are implanted. For single atom device development, control over the absolute number of ions is needed and ions have to be placed with high spatial resolution. In the following sections we will discuss a series of approaches to single ion implantation with regard to single ion impact sensing and control of single ion positioning.

Schenkel, Thomas

2010-06-11T23:59:59.000Z

202

Superlattice doped layers for amorphous silicon photovoltaic cells  

DOE Patents [OSTI]

Superlattice doped layers for amorphous silicon photovoltaic cells comprise a plurality of first and second lattices of amorphous silicon alternatingly formed on one another. Each of the first lattices has a first optical bandgap and each of the second lattices has a second optical bandgap different from the first optical bandgap. A method of fabricating the superlattice doped layers also is disclosed.

Arya, Rajeewa R. (Doylestown, PA)

1988-01-12T23:59:59.000Z

203

Raman Measurements on Electrochemically Doped Single-Walled Carbon Nanotubes  

E-Print Network [OSTI]

Raman Measurements on Electrochemically Doped Single-Walled Carbon Nanotubes P. M. Rafailov, M and studied the Raman response of electro- chemically doped single-walled carbon nanotubes (SWNT) using different salt solutions. The fre- quency shift of the radial breathing mode (RBM) and the high-energy mode

Nabben, Reinhard

204

Impurity Doping Effect in High T c Superconductors  

E-Print Network [OSTI]

Impurity Doping Effect in High T c Superconductors Yong­Jihn Kim and K. J. Chang Department observed that impurity doping and/or ion­beam­induced dam­ age in high T c superconductors cause a metal­ calization effect on superconductivity, we examine the variation of T c with increasing of impurity

205

Controllable N-Doping of Graphene Beidou Guo,,  

E-Print Network [OSTI]

Controllable N-Doping of Graphene Beidou Guo,, Qian Liu, Erdan Chen, Hewei Zhu, Liang Fang in graphene are central to many electronic applications of graphene. Here we report N-doped graphene obtained by NH3 annealing after N+ -ion irradiation of graphene samples. First, the evolution of the graphene

Gong, Jian Ru

206

Femtosecond Laser Ablation of Silicon: Nanoparticles, Doping and Photovoltaics  

E-Print Network [OSTI]

Femtosecond Laser Ablation of Silicon: Nanoparticles, Doping and Photovoltaics A thesis presented Laser Ablation of Silicon: Nanoparticles, Doping and Photovoltaics Eric Mazur Brian R. Tull Abstract irradiated surface layer to the grain boundaries. #12;iv Lastly, we measure the photovoltaic properties

Mazur, Eric

207

RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS  

E-Print Network [OSTI]

RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS PART III: CYCLOPENTENE-length article SHORTENED RUNNING TITLE : METHANE FLAMES DOPED BY CYCLOPENTENE * E-mail : pierre with the studies presented in the parts I and II of this paper, the structure of a laminar rich premixed methane

Paris-Sud XI, Université de

208

Europium-doped yttrium silicate nanophosphors prepared by flame synthesis  

E-Print Network [OSTI]

Europium-doped yttrium silicate nanophosphors prepared by flame synthesis Xiao Qin a,*, Yiguang Ju; accepted 7 November 2006 Available online 22 December 2006 Abstract Europium-doped yttrium silicate (Y2SiO5 properties 1. Introduction Yttrium silicate (Y2SiO5) is an important luminescent host material for various

Bernhard, Stefan

209

Nitrogen doped zinc oxide thin film  

SciTech Connect (OSTI)

To summarize, polycrystalline ZnO thin films were grown by reactive sputtering. Nitrogen was introduced into the films by reactive sputtering in an NO{sub 2} plasma or by N{sup +} implantation. All ZnO films grown show n-type conductivity. In unintentionally doped ZnO films, the n-type conductivities are attributed to Zn{sub i}, a native shallow donor. In NO{sub 2}-grown ZnO films, the n-type conductivity is attributed to (N{sub 2}){sub O}, a shallow double donor. In NO{sub 2}-grown ZnO films, 0.3 atomic % nitrogen was found to exist in the form of N{sub 2}O and N{sub 2}. Upon annealing, N{sub 2}O decomposes into N{sub 2} and O{sub 2}. In furnace-annealed samples N{sub 2} redistributes diffusively and forms gaseous N{sub 2} bubbles in the films. Unintentionally doped ZnO films were grown at different oxygen partial pressures. Zni was found to form even at oxygen-rich condition and led to n-type conductivity. N{sup +} implantation into unintentionally doped ZnO film deteriorates the crystallinity and optical properties and leads to higher electron concentration. The free electrons in the implanted films are attributed to the defects introduced by implantation and formation of (N{sub 2}){sub O} and Zni. Although today there is still no reliable means to produce good quality, stable p-type ZnO material, ZnO remains an attractive material with potential for high performance short wavelength optoelectronic devices. One may argue that gallium nitride was in a similar situation a decade ago. Although we did not obtain any p-type conductivity, we hope our research will provide a valuable reference to the literature.

Li, Sonny X.

2003-12-15T23:59:59.000Z

210

IR permittivities for silicides and doped silicon  

SciTech Connect (OSTI)

The complex permittivity for Pt, Pd, Ni, and Ti-silicide films as well as heavily doped p- and n-type silicon were determined by ellipsometry over the energy range 0.031 eV to 4.0 eV. Fits to the Drude model gave bulk plasma and relaxation frequencies. Rutherford backscattering spectroscopy, X-ray diffraction, scanning electron microscopy, secondary ion mass spectrometry, and four-point probe measurements complemented the optical characterization. Calculations from measured permittivities of waveguide loss and mode confinement suggest that the considered materials are better suited for long-wavelength surface-plasmon-polariton waveguide applications than metal films.

Cleary, J. W.; Peale, R. E.; Smith, C. W.; Ishigami, M. [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Shelton, D. J.; Boreman, G. D. [College of Optics (CREOL), University of Central Florida, Orlando, Florida 32816 (United States); Soref, R.; Drehman, A.; Buchwald, W. R. [Sensors Directorate, Air Force Research Laboratory, Hanscom Air Force Base, Massachusetts 01731 (United States)

2010-04-15T23:59:59.000Z

211

Scintillation of rare earth doped fluoride nanoparticles  

SciTech Connect (OSTI)

The scintillation response of rare earth (RE) doped core/undoped (multi-)shell fluoride nanoparticles was investigated under x-ray and alpha particle irradiation. A significant enhancement of the scintillation response was observed with increasing shells due: (i) to the passivation of surface quenching defects together with the activation of the REs on the surface of the core nanoparticle after the growth of a shell, and (ii) to the increase of the volume of the nanoparticles. These results are expected to reflect a general aspect of the scintillation process in nanoparticles, and to impact radiation sensing technologies that make use of nanoparticles.

Jacobsohn, L. G.; McPherson, C. L.; Sprinkle, K. B.; Ballato, J. [Center for Optical Materials Science and Engineering Technologies (COMSET), and School of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States); Yukihara, E. G. [Physics Department, Oklahoma State University, Stillwater, Oklahoma 74078-3072 (United States); DeVol, T. A. [Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, South Carolina 29634-0905 (United States)

2011-09-12T23:59:59.000Z

212

Quantum electrodynamics with anisotropic scaling: Heisenberg-Euler action and Schwinger pair production in the bilayer graphene  

E-Print Network [OSTI]

We discuss quantum electrodynamics emerging in the vacua with anisotropic scaling. Systems with anisotropic scaling were suggested by Horava in relation to the quantum theory of gravity. In such vacua the space and time are not equivalent, and moreover they obey different scaling laws, called the anisotropic scaling. Such anisotropic scaling takes place for fermions in bilayer graphene, where if one neglects the trigonal warping effects the massless Dirac fermions have quadratic dispersion. This results in the anisotropic quantum electrodynamics, in which electric and magnetic fields obey different scaling laws. Here we discuss the Heisenberg-Euler action and Schwinger pair production in such anisotropic QED

M. I. Katsnelson; G. E. Volovik

2012-03-19T23:59:59.000Z

213

Electron density analysis of the effects of sugars on the structure of lipid bilayers at low hydration - a preliminary study  

SciTech Connect (OSTI)

Small angle X-ray scattering is used to study the effects of sugars on membranes during dehydration. Previous work has shown that the bilayer and chain-chain repeat spacings of DPPC bilayers are relatively unaffected by the presence of sugars. In this work we present a preliminary analysis of the electron density profiles of DPPC in the presence of sugars at low hydration. The difficulties of determining the correct phasing are discussed. Sugars and other small solutes have been shown to have an important role in improving the tolerance of a range of species to desiccation and freezing. In particular it has been shown that sugars can stabilize membranes in the fluid membrane phase during dehydration, and in the fully dehydrated state. Equivalently, at a particular hydration, the presence of sugars lowers the transition temperature between the fluid and gel phases. There are two competing models for explaining the effects of sugars on membrane phase transition temperatures. One, designated the water replacement hypothesis (WRH) states that sugars hydrogen bond to phospholipid headgroups, thus hindering the fluid-gel phase transition. One version of this model suggests that certain sugars (such as trehalose) achieve the measured effects by inserting between the phospholipid head groups. An alternative model explains the observed effects of sugars in terms of the sugars effect on the hydration repulsion that develops between opposing membranes during dehydration. The hydration repulsion leads to a lateral compressive stress in the bilayer which squeezes adjacent lipids more closely together, resulting in a transition to the gel phase. When sugars are present, their osmotic and volumetric effects reduce the hydration repulsion, reduce the compressive stress in the membranes, and therefore tend to maintain the average lateral separation between lipids. This model is called the hydration forces explanation (HFE). We recently showed that neither mono- nor di-saccharides affect the average distance between lipid chains in the bilayer, supporting the predictions of the HFE. In this paper we further investigate the effects of sugars on membrane structure by conducting electron density analysis of recent data. This preliminary analysis sheds additional light onto the effects of sugars on membrane structure.

Lenné, T.; Kent, B.; Koster, K.L.; Garvey, C.J.; Bryant, G. (ANSTO); (USD); (ANU); (RMIT)

2012-02-06T23:59:59.000Z

214

Structural Detuning of Pump Absorption Rate in Doped Fiber for the Enhancement of Power Conversion Efficiency  

E-Print Network [OSTI]

Structural Detuning of Pump Absorption Rate in Doped Fiber for the Enhancement of Power Conversion Doped Fiber Amplifier. With proper adjustments on doping profiles for the reduction of pump absorption rate, it becomes possible to optimize pump evolution map inside the doped fiber to get better power

Park, Namkyoo

215

LASER TRANSFER DOPING USING AMORPHOUS SILICON Rafel Ferr (Correspondence author)1  

E-Print Network [OSTI]

LASER TRANSFER DOPING USING AMORPHOUS SILICON Rafel Ferré (Correspondence author)1 , Ralf Gogolin1@isfh.de ABSTRACT: We demonstrate and characterize "Laser Transfer Doping" (LTD) for producing locally doped regions. For this purpose we use nanosecond pulsed laser for transferring phosphorus doped amorphous silicon from a carrier

216

Color stable manganese-doped phosphors  

DOE Patents [OSTI]

A process for preparing color stable Mn.sup.+4 doped phosphors includes providing a phosphor of formula I; A.sub.x[MF.sub.y]:Mn.sup.+4 I and contacting the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid; A.sub.x[MF.sub.y]; II wherein A is Li, Na, K, Rb, Cs, NR.sub.4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7. In particular embodiments, M is Si, Ge, Sn, Ti, Zr, or a combination thereof. A lighting apparatus capable of emitting white light includes a semiconductor light source; and a phosphor composition radiationally coupled to the light source, and which includes a color stable Mn.sup.+4 doped phosphor.

Lyons, Robert Joseph (Burnt Hills, NY); Setlur, Anant Achyut (Niskayuna, NY); Deshpande, Anirudha Rajendra (Twinsburg, OH); Grigorov, Ljudmil Slavchev (Sofia, BG)

2012-08-28T23:59:59.000Z

217

Transparent conducting oxides: A -doped superlattice approach  

SciTech Connect (OSTI)

Two-dimensional electron gases (2DEGs) at the interface of oxide heterostructures have been the subject of recent experiment and theory, due to the intriguing phenomena that occur in confined electronic states. However, while much has been done to understand the origin of 2DEGs and related phenomena, very little has been explored with regards to the control of conduction pathways and the distribution of charge carriers. Using first principles simulations and experimental thin film synthesis methods, we examine the effect of dimensionality on carrier transport in La delta-doped SrTiO3 (STO) superlattices, as a function of the thickness of the insulating STO spacer. Our computed Fermi surfaces and layer-resolved carrier density proles demonstrate that there is a critical thickness of the STO spacer, below which carrier transport is dominated by three-dimensional conduction of interface charges arising from appreciable overlap of the quantum mechanical wavefunctions between neighboring delta-doped layers. We observe that, experimentally, these superlattices remain highly transparent to visible light. Band structure calculations indicate that this is a result of the appropriately large gap between the O 2p and Ti d states. The tunability of the quantum mechanical wavefunctions and the optical transparency highlight the potential for using oxide heterostructures in novel opto-electronic devices; thus providing a route to the creation of novel transparent conducting oxides.

Cooper, Valentino R [ORNL; Seo, Sung Seok A. [University of Kentucky, Lexington; Lee, Suyoun [ORNL; Kim, Jun Sung [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Choi, Woo Seok [ORNL; Okamoto, Satoshi [ORNL; Lee, Ho Nyung [ORNL

2014-01-01T23:59:59.000Z

218

Tunneling magnetoresistance tuned by a vertical electric field in an AA-stacked graphene bilayer with double magnetic barriers  

SciTech Connect (OSTI)

We investigate the effect of a vertical electric field on the electron tunneling and magnetoresistance in an AA-stacked graphene bilayer modulated by the double magnetic barriers with parallel or antiparallel configuration. The results show that the electronic transmission properties in the system are sensitive to the magnetic-barrier configuration and the bias voltage between the graphene layers. In particular, it is found that for the antiparallel configuration, within the low energy region, the blocking effect is more obvious compared with the case for the parallel configuration, and even there may exist a transmission spectrum gap which can be arbitrarily tuned by the field-induced interlayer bias voltage. We also demonstrate that the significant discrepancy between the conductance for both parallel and antiparallel configurations would result in a giant tunneling magnetoresistance ratio, and further the maximal magnetoresistance ratio can be strongly modified by the interlayer bias voltage. This leads to the possible realization of high-quality magnetic sensors controlled by a vertical electric field in the AA-stacked graphene bilayer.

Wang, Dali, E-mail: wangdali@mail.ahnu.edu.cn [Department of Physics and Center for Nano Science and Technology, Anhui Normal University, Wuhu 241000 (China); National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Jin, Guojun, E-mail: gjin@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)

2013-12-21T23:59:59.000Z

219

Step-edge-induced resistance anisotropy in quasi-free-standing bilayer chemical vapor deposition graphene on SiC  

SciTech Connect (OSTI)

The transport properties of quasi-free-standing (QFS) bilayer graphene on SiC depend on a range of scattering mechanisms. Most of them are isotropic in nature. However, the SiC substrate morphology marked by a distinctive pattern of the terraces gives rise to an anisotropy in graphene's sheet resistance, which may be considered an additional scattering mechanism. At a technological level, the growth-preceding in situ etching of the SiC surface promotes step bunching which results in macro steps ?10?nm in height. In this report, we study the qualitative and quantitative effects of SiC steps edges on the resistance of epitaxial graphene grown by chemical vapor deposition. We experimentally determine the value of step edge resistivity in hydrogen-intercalated QFS-bilayer graphene to be ?190???m for step height h{sub S}?=?10?nm and provide proof that it cannot originate from mechanical deformation of graphene but is likely to arise from lowered carrier concentration in the step area. Our results are confronted with the previously reported values of the step edge resistivity in monolayer graphene over SiC atomic steps. In our analysis, we focus on large-scale, statistical properties to foster the scalable technology of industrial graphene for electronics and sensor applications.

Ciuk, Tymoteusz [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Cakmakyapan, Semih; Ozbay, Ekmel [Department of Electrical and Electronics Engineering, Department of Physics, Nanotechnology Research Center, Bilkent University, 06800 Bilkent, Ankara (Turkey); Caban, Piotr; Grodecki, Kacper; Pasternak, Iwona; Strupinski, Wlodek, E-mail: wlodek.strupinski@itme.edu.pl [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Krajewska, Aleksandra [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw (Poland); Szmidt, Jan [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland)

2014-09-28T23:59:59.000Z

220

P solid-state NMR studies of the dependence of inter-bilayer water dynamics on lipid headgroup structure and membrane peptides  

E-Print Network [OSTI]

2D 1 H­31 P solid-state NMR studies of the dependence of inter-bilayer water dynamics on lipid Revised 29 September 2008 Available online 5 October 2008 Keywords: Water Lipid membranes Solid-state NMR headgroup structure and membrane peptides Tim Doherty, Mei Hong * Department of Chemistry, Iowa State

Hong, Mei

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Interfacing 2D and 3D Topological Insulators: Bi(111) Bilayer on Bi2Te3 Toru Hirahara,1,* Gustav Bihlmayer,2  

E-Print Network [OSTI]

Interfacing 2D and 3D Topological Insulators: Bi(111) Bilayer on Bi2Te3 Toru Hirahara,1,* Gustav Topological insulators, realized in materials with strong spin-orbit interaction, are gaining increasing-dimensional (1D) edge states compared to the 2D surface states of 3D topological insulators, only a few works

Hasegawa, Shuji

222

Time-resolved FTIR spectroscopy for monitoring protein dynamics exemplified by functional studies of Ras protein bound to a lipid bilayer  

E-Print Network [OSTI]

bilayers can be investigated in near physiological con- ditions with the attenuated total reflection (ATR online 22 August 2011 Keywords: Infrared Time-resolved Difference spectroscopy Rapid scan Step scan GTPases GTP Caged-substances Ras Isotopic labeling Band assignment Global fit Attenuated total reflection

Gerwert, Klaus

223

Electron transfer through a lipid-bilayer-membrane-aqueous-solution interface and kinetics of the oxidation of viologen radicals in homogeneous and vesicular systems  

SciTech Connect (OSTI)

The purpose of the present work was to study the influence of the nature of the oxidizing agent on the rate constant of the oxidation of viologen radicals in homogeneous and vesicular systems by water-soluble oxidizing agents. In this work the authors used the following water-soluble viologens: methyl viologen, sulfoethyl viologen, trimethylaminopropyl viologen, and octadecyl viologen, which is soluble only in a lipid bilayer. The rate constant for the oxidation of a viologen radical cation in a lipid bilayer by electron acceptors in the aqueous phase, in contrast to the homogeneous reaction, is lower than the rate constant of the diffusion-controlled reaction. The rate of electron transfer on the interface is determined by the interaction of the reactants with the lipid bilayer. The rate constant for electron transfer from a viologen radical cation near the inner surface of a lipid bilayer to viologen near the outer surface with the formation of a radical which is available for oxidation in the external aqueous phase has been determined and has been found to be independent of the nature of the oxidizing agent.

Shafirovich, V.Ya.; Levin, P.P.; Khannanov, N.K.; Kuz'min, V.A.

1986-10-10T23:59:59.000Z

224

CVD Growth of Mono-and Bi-Layer Graphene from Ethanol Xiao Chen, Pei Zhao, Bo Hou, Shohei Chiashi and Shigeo Maruyama  

E-Print Network [OSTI]

CVD Growth of Mono- and Bi-Layer Graphene from Ethanol Xiao Chen, Pei Zhao, Bo Hou, Shohei Chiashi substrates has been provn effective in the synthesis of graphene. But before application in graphene electronics, the quality of the synthesized graphene needs to be improved. Therefore a reliable method to grow

Maruyama, Shigeo

225

Conformational plasticity of the influenza A M2 transmembrane helix in lipid bilayers under varying pH, drug binding, and membrane thickness  

E-Print Network [OSTI]

Conformational plasticity of the influenza A M2 transmembrane helix in lipid bilayers under varying cues, thus conformational plasticity is important for function. The influenza A M2 protein forms spectroscopy to examine the conformational plasticity of membrane-bound transmembrane domain of M2 (M2TM). 13 C

Hong, Mei

226

Water-Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers Investigated by Solid-State Nuclear Magnetic Resonance Spectroscopy  

E-Print Network [OSTI]

Water-Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers InvestigatedVised Manuscript ReceiVed: February 16, 2010 The interaction of an arginine (Arg) residue with water HETCOR experiments, we unambiguously assigned a water-guanidinium cross-peak that is distinct from

Hong, Mei

227

In-situ high resolution transmission electron microscopy observation of silicon nanocrystal nucleation in a SiO{sub 2} bilayered matrix  

SciTech Connect (OSTI)

Solid-state nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix was observed at temperatures as low as 450?°C. This was achieved by aberration corrected high-resolution transmission electron microscopy (HRTEM) with real-time in-situ heating up to 600?°C. This technique is a valuable characterization tool especially with the recent interest in Si nanostructures for light emitting devices, non-volatile memories, and third-generation photovoltaics which all typically require a heating step in their fabrication. The control of size, shape, and distribution of the Si nanocrystals are critical for these applications. This experimental study involves in-situ observation of the nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix fabricated through radio frequency co-sputtering. The results show that the shapes of Si nanocrystals in amorphous SiO{sub 2} bilayered matrices are irregular and not spherical, in contrast to many claims in the literature. Furthermore, the Si nanocrystals are well confined within their layers by the amorphous SiO{sub 2}. This study demonstrates the potential of in-situ HRTEM as a tool to observe the real time nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix. Furthermore, ideas for improvements on this in-situ heating HRTEM technique are discussed.

Yang, T. C.-J., E-mail: terry.yang@unsw.edu.au; Wu, L.; Lin, Z.; Jia, X.; Puthen-Veettil, B.; Zhang, T.; Conibeer, G.; Perez-Wurfl, I. [School of Photovoltaic and Renewable Engineering, University of New South Wales, Sydney, New South Wales 2052 (Australia); Kauffmann, Y.; Rothschild, A. [Department of Materials Science and Engineering, Technion – Israel Institute of Technology, Technion City, Haifa 32000 (Israel)

2014-08-04T23:59:59.000Z

228

CVD Growth of Mono-and Bi-Layer Graphene from Ethanol Xiao Chen, Pei Zhao, Bo Hou, Erik Einarsson, Shohei Chiashi and Shigeo Maruyama  

E-Print Network [OSTI]

CVD Growth of Mono- and Bi-Layer Graphene from Ethanol Xiao Chen, Pei Zhao, Bo Hou, Erik Einarsson precursors have been employed to synthesize graphene, such as methane [6], ethane [7] and ethanol [8]. Here we report a systematic study on CVD growth of graphene on Cu and Ni substrates from ethanol. Ethanol

Maruyama, Shigeo

229

Self-doped molecular composite battery electrolytes  

DOE Patents [OSTI]

This invention is in solid polymer-based electrolytes for battery applications. It uses molecular composite technology, coupled with unique preparation techniques to render a self-doped, stabilized electrolyte material suitable for inclusion in both primary and secondary batteries. In particular, a salt is incorporated in a nano-composite material formed by the in situ catalyzed condensation of a ceramic precursor in the presence of a solvated polymer material, utilizing a condensation agent comprised of at least one cation amenable to SPE applications. As such, the counterion in the condensation agent used in the formation of the molecular composite is already present as the electrolyte matrix develops. This procedure effectively decouples the cation loading levels required for maximum ionic conductivity from electrolyte physical properties associated with condensation agent loading levels by utilizing the inverse relationship discovered between condensation agent loading and the time domain of the aging step.

Harrup, Mason K.; Wertsching, Alan K.; Stewart, Frederick F.

2003-04-08T23:59:59.000Z

230

Fluorine compounds for doping conductive oxide thin films  

DOE Patents [OSTI]

Methods of forming a conductive fluorine-doped metal oxide layer on a substrate by chemical vapor deposition are described. The methods may include heating the substrate in a processing chamber, and introducing a metal-containing precursor and a fluorine-containing precursor to the processing chamber. The methods may also include adding an oxygen-containing precursor to the processing chamber. The precursors are reacted to deposit the fluorine-doped metal oxide layer on the substrate. Methods may also include forming the conductive fluorine-doped metal oxide layer by plasma-assisted chemical vapor deposition. These methods may include providing the substrate in a processing chamber, and introducing a metal-containing precursor, and a fluorine-containing precursor to the processing chamber. A plasma may be formed that includes species from the metal-containing precursor and the fluorine-containing precursor. The species may react to deposit the fluorine-doped metal oxide layer on the substrate.

Gessert, Tim; Li, Xiaonan; Barnes, Teresa M; Torres, Jr., Robert; Wyse, Carrie L

2013-04-23T23:59:59.000Z

231

atomic nitrogen doping: Topics by E-print Network  

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

Chris Greene 3:30 - 3:50 Nick Brewer, Wisconsin, Left-handed electromagnetic waves in rare-earth doped Kemner, Ken 154 4, 26412665, 2007 Nitrogen retention Physics Websites...

232

Muon spin depolarization in nonmagnetic metals doped with paramagnetic impurities  

SciTech Connect (OSTI)

The diffusion of muons and their magnetic interactions are treated by describing the physics to be learned from experiments which measure muon depolarization in metallic hosts doped with dilute concentrations of magnetic impurities. (GHT)

Heffner, R.H.

1980-01-01T23:59:59.000Z

233

Self-doping effects in epitaxially grown graphene  

E-Print Network [OSTI]

The electronic properties of graphene, Rev. Mod. Phys. (inE?ects in Epitaxially-Grown Graphene D.A. Siegel, 1, 2 S.Y.2009) Abstract Self-doping in graphene has been studied by

Siegel, David A.

2009-01-01T23:59:59.000Z

234

Doped carbon nanostructure field emitter arrays for infrared imaging  

DOE Patents [OSTI]

An infrared imaging device and method for making infrared detector(s) having at least one anode, at least one cathode with a substrate electrically connected to a plurality of doped carbon nanostructures; and bias circuitry for applying an electric field between the anode and the cathode such that when infrared photons are adsorbed by the nanostructures the emitted field current is modulated. The detectors can be doped with cesium to lower the work function.

Korsah, Kofi (Knoxville, TN) [Knoxville, TN; Baylor, Larry R (Farragut, TN) [Farragut, TN; Caughman, John B (Oak Ridge, TN) [Oak Ridge, TN; Kisner, Roger A (Knoxville, TN) [Knoxville, TN; Rack, Philip D (Knoxville, TN) [Knoxville, TN; Ivanov, Ilia N (Knoxville, TN) [Knoxville, TN

2009-10-27T23:59:59.000Z

235

Repulsive van der Waals forces due to hydrogen exposure on bilayer Graphene  

E-Print Network [OSTI]

We consider the effect of atomic hydrogen exposure to a system of two undoped sheets of graphene grown near a silica surface (the first adsorbed to the surface and the second freestanding near the surface). In the absence of atomic hydrogen the van der Waals force between the sheets is attractive at all separations causing the sheets to come closer together. However, with addition of atomic hydrogen between the sheets the long range van der Waals interaction turns repulsive at a critical concentration. The underlying triple layer structure (SiO2 -Atomic Hydrogen Gas -Air) gives rise to a long range repulsion that at large enough separations dominates over the more rapidly decaying attraction between the two-dimensional undoped graphene sheets (and between the outer graphene sheet and SiO2). This may be an avenue to tune the separation between two graphene sheets with the gas concentration. Doping of the graphene layers increases the attractive part of the interaction and hence reduces the net repulsive interaction.

Mathias Boström; Bo E. Sernelius

2012-01-05T23:59:59.000Z

236

3>2>1: Investigation of Single Particle Particle and Many Body Physics in Dual-Gated 1,2,3 Layers of Graphene  

E-Print Network [OSTI]

to the VI profile of Josephson junctions. At the largest B,projects on suspended Josephson junctions and effects ofgraphene-based Josephson junction. Such a system has been

Velasco, Jairo

2012-01-01T23:59:59.000Z

237

Time-resolved X-ray diffraction studies of laser-induced acoustic wave propagation in bilayer metallic thin crystals  

SciTech Connect (OSTI)

Phonon propagation across the interface of a Cu/Ag(111) bilayer and transient lattice disorder, induced by a femtosecond 267?nm pulse, in Ag(111) crystal have been measured by means of time resolved X-ray diffraction. A “blast” force due to thermal stress induced by suddenly heated electrons is formed within two picoseconds after excitation and its “blast wave” propagation through the interface and Ag (111) crystal was monitored by the shift and broadening of the rocking curve, I vs. ?, as a function of time after excitation. Lattice disorder, contraction and expansion as well as thermal strain formation and wave propagation have also been measured. The experimental data and mechanism proposed are supported by theoretical simulations.

Er, Ali Oguz [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, Kentucky 42101 (United States); Tang, Jau, E-mail: jautang@gate.sinica.edu.tw, E-mail: prentzepis@ece.tamu.edu [Research Center for Applied Sciences Academia Sinica, Taipei, Taiwan (China); Chen, Jie [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Rentzepis, Peter M., E-mail: jautang@gate.sinica.edu.tw, E-mail: prentzepis@ece.tamu.edu [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States)

2014-09-07T23:59:59.000Z

238

Excitons in a mirror: Formation of “optical bilayers” using MoS{sub 2} monolayers on gold substrates  

SciTech Connect (OSTI)

We report coupling of excitons in monolayers of molybdenum disulphide to their mirror image in an underlying gold substrate. Excitons at the direct band gap are little affected by the substrate whereas strongly bound C-excitons associated with a van-Hove singularity change drastically. On quartz substrates only one C-exciton is visible (in the blue) but on gold substrates a strong red-shifted extra resonance in the green is seen. Exciton coupling to its image leads to formation of a “mirror biexciton” with enhanced binding energy. Estimates of this energy shift in an emitter-gold system match experiments well. The absorption spectrum of MoS{sub 2} on gold thus resembles a bilayer of MoS{sub 2} which has been created by optical coupling. Additional top-mirrors produce an “optical bulk.”.

Mertens, Jan; Baumberg, Jeremy J., E-mail: jjb12@cam.ac.uk [Nanophotonics Centre, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Shi, Yumeng; Yang, Hui Ying, E-mail: yanghuiying@sutd.edu.sg [Pillar of Engineering Product Development, Singapore University of Technology and Design, Singapore 138682 (Singapore); Molina-Sánchez, Alejandro; Wirtz, Ludger [Physics and Materials Science Research Unit, University of Luxembourg, L-1511 Luxembourg (Luxembourg)

2014-05-12T23:59:59.000Z

239

Tunable electronic structures of p-type Mg doping in AlN nanosheet  

SciTech Connect (OSTI)

The p-type impurity properties are investigated in the Mg-doped AlN nanosheet by means of first-principles calculations. Numerical results show that the transition energy levels reduce monotonously with the increase in Mg doping concentration in the Mg-doped AlN nanosheet systems, and are lower than that of the Mg-doped bulk AlN case for the cases with larger doping concentration. Moreover, Mg substituting Al atom is energy favorably under N-rich growth experimental conditions. These results are new and interesting to further improve p-type doping efficiency in the AlN nanostructures.

Peng, Yuting; Xia, Congxin, E-mail: xiacongxin@htu.edu.cn; Zhang, Heng; Wang, Tianxing; Wei, Shuyi [Department of Physics, Henan Normal University, Xinxiang, Henan 453007 (China); Jia, Yu [School of Physics and Engineering, Zhengzhou University, Zhengzhou 450052 (China)

2014-07-28T23:59:59.000Z

240

Trench process and structure for backside contact solar cells with polysilicon doped regions  

DOE Patents [OSTI]

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

De Ceuster, Denis (Woodside, CA); Cousins, Peter John (Menlo Park, CA); Smith, David D. (Campbell, CA)

2010-12-14T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Trench process and structure for backside contact solar cells with polysilicon doped regions  

DOE Patents [OSTI]

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

De Ceuster, Denis; Cousins, Peter John; Smith, David D

2014-03-18T23:59:59.000Z

242

Trench process and structure for backside contact solar cells with polysilicon doped regions  

DOE Patents [OSTI]

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

De Ceuster, Denis; Cousins, Peter John; Smith, David D

2013-05-28T23:59:59.000Z

243

Nanocrystal bilayer for tandem catalysis Yusuke Yamada1, Chia-Kuang Tsung1,2, Wenyu Huang1,2, Ziyang Huo1, Susan E. Habas1,2,  

E-Print Network [OSTI]

, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst-generation energy conversion and storage technol- ogies1,2 . Although industrial catalysts can be optimized

Yang, Peidong

244

Color stable manganese-doped phosphors  

DOE Patents [OSTI]

A lighting apparatus capable of emitting white light includes a semiconductor light source; and a phosphor material radiationally coupled to the light source. The phosphor material includes a color-stable Mn.sup.+4 doped phosphor prepared by a process including providing a phosphor of formula I; A.sub.x[MF.sub.y]:Mn.sup.+4 I and contacting the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid; A.sub.x[MF.sub.y]; II wherein A is Li, Na, K, Rb, Cs, NR.sub.4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7. In particular embodiments, M is Si, Ge, Sn, Ti, Zr, or a combination thereof.

Lyons, Robert Joseph; Setlur, Anant Achyut; Deshpande, Anirundha Rajendra; Grigorov, Ljudmil Slavchev

2014-04-29T23:59:59.000Z

245

Iron (III) Chloride doping of large-area chemical vapor deposition graphene  

E-Print Network [OSTI]

Chemical doping is an effective method of reducing the sheet resistance of graphene. This thesis aims to develop an effective method of doping large area Chemical Vapor Deposition (CVD) graphene using Iron (III) Chloride ...

Song, Yi, S.M. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

246

Electrical properties of Er-doped In0.53Ga0.47As  

E-Print Network [OSTI]

semiconductors doped with rare- earth elements is of signi?applications. 4 However, rare-earth elements, such as Er,pos- sibility of using rare-earth elements for doping narrow

2011-01-01T23:59:59.000Z

247

Influence of samaria doping on the resistance of ceria thin films...  

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

doping on the resistance of ceria thin films and its implications to the planar oxygen sensing devices. Influence of samaria doping on the resistance of ceria thin films and...

248

Growth of Cr-doped TiO Films in the Rutile and Anatase Structures...  

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

of Cr-doped TiO Films in the Rutile and Anatase Structures by Oxygen Plasma Assisted Molecular Beam Epitaxy . Growth of Cr-doped TiO Films in the Rutile and Anatase Structures by...

249

Ammonia Sensors Based on Doped-Sol-Gel-Tipped Optical Fibers...  

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

Sensors Based on Doped-Sol-Gel-Tipped Optical Fibers for Catalyst System Diagnostics Ammonia Sensors Based on Doped-Sol-Gel-Tipped Optical Fibers for Catalyst System Diagnostics...

250

ccsd-00018793,version3-28Apr2006 Doping quantum dimer models on the square lattice  

E-Print Network [OSTI]

. Evidence for an extended region of a doped VBS phase exhibiting holon pairing but no phase separation

Boyer, Edmond

251

Bulk optical damage thresholds for doped and undoped, crystalline and ceramic yttrium aluminum garnet  

SciTech Connect (OSTI)

We measured the bulk optical damage thresholds of pure and Nd-doped ceramic yttrium aluminum garnet (YAG), and of pure, Nd-doped, Cr-doped, and Yb-doped crystalline YAG. We used 9.9 ns, 1064 nm, single-longitudinal mode, TEM00 pulses, to determine that the breakdown thresholds are deterministic, with multiple-pulse thresholds ranging from 1.1 to 2.2 kJ/cm{sup 2}.

Do, Binh T.; Smith, Arlee V.

2009-06-20T23:59:59.000Z

252

Role of dye structure in photoinduced reorientation of dye-doped liquid crystals  

E-Print Network [OSTI]

-doped nematic liquid crystals has been measured for a homologous set of dyes belonging to the anthraquinone

Marrucci, Lorenzo

253

Chemical Preparation of Pure and Strontium-and/or Magnesium-Doped Lanthanum Gallate Powders  

E-Print Network [OSTI]

Chemical Preparation of Pure and Strontium- and/or Magnesium-Doped Lanthanum Gallate Powders A. Cu) ceramics that have been doped with strontium and/or magnesium are known to have superior oxygen re- cently synthesized strontium- and magnesium-doped LaGaO3 ceramics, using the conventional "solid

Tas, A. Cuneyt

254

Comparison study of biomimetic strontium-doped calcium phosphate coatings by electrochemical deposition and air plasma  

E-Print Network [OSTI]

Comparison study of biomimetic strontium-doped calcium phosphate coatings by electrochemical April 2012 Ã? Springer Science+Business Media, LLC 2012 Abstract In this study, strontium-doped calcium of the strontium-doped calcium phosphate coatings were evaluated using bone cell culture using MC3T3-E1 osteoblast

Meng, Yizhi

255

Passively harmonic mode locked erbium doped fiber soliton laser with carbon nanotubes based  

E-Print Network [OSTI]

Passively harmonic mode locked erbium doped fiber soliton laser with carbon nanotubes based. Tokumoto, H. Kataura, and Y. Achiba, "Sub-200-fs pulsed erbium- doped fiber laser using a carbon nanotube fs erbium-doped fiber laser mode locked with a cellulose polymer film containing single-wall carbon

Turitsyn, Sergei K.

256

Electrochemical studies of moderately boron doped polycrystalline diamond in non-aqueous solvent  

E-Print Network [OSTI]

Electrochemical studies of moderately boron doped polycrystalline diamond in non-aqueous solvent being marketed [83,84]. The first paper on the electrochemistry of boron doped polycrystalline diamond The electrochemistry of boron doped diamond is currently an active field of research. In the majority of studies

Bristol, University of

257

Spatially-Correlated Microstructure and Superconductivity in Polycrystalline Boron-Doped Diamond  

E-Print Network [OSTI]

Spatially-Correlated Microstructure and Superconductivity in Polycrystalline Boron-Doped Diamond F tunneling spectroscopies are performed below 100 mK on nano-crystalline boron-doped diamond films been discovered in heavily doped group IV covalent semicon- ductors [1], in particular diamond [2

258

FIELD EMISSION FROM BORON-DOPING POLYCRYSTALLINE DIAMOND FILMS ON SILICON  

E-Print Network [OSTI]

FIELD EMISSION FROM BORON-DOPING POLYCRYSTALLINE DIAMOND FILMS ON SILICON J. A. N. Gonçalves, G. M material fail. The field emission current from boron-doped polycrystalline diamond films grown by hot Campos, SP, Brazi Abstract This work deals with the study and development of the boron-doped diamond

259

Hafnium-doped tantalum oxide high-k gate dielectric films for future CMOS technology  

E-Print Network [OSTI]

of the doped films were explained by their compositions and bond structures. The Hf-doped TaOx film is a potential high-k gate dielectric for future MOS transistors. A 5 Ã?Â? tantalum nitride (TaNx) interface layer has been inserted between the Hf-doped Ta...

Lu, Jiang

2007-04-25T23:59:59.000Z

260

Active waveguide fabrication in erbium-doped oxyfluoride silicate glass using femtosecond pulses  

E-Print Network [OSTI]

Active waveguide fabrication in erbium-doped oxyfluoride silicate glass using femtosecond pulses R September 2005 By directly writing waveguides inside bulk erbium-doped oxyfluoride silicate glass using-doped oxyfluoride silicate glass using femtosecond pulses.3 These glasses, also fabri- cated by us, have been shown

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

ChemFeeds -The targeted delivery of multicomponent cargos to cancer cells by nanoporous particle-supported lipid bilayers http://www.chemfeeds.com/comments.php?doi=10.1038/nmat2992[4/21/2011 11:45:43 AM  

E-Print Network [OSTI]

-supported lipid bilayers http://www.chemfeeds.com/comments.php?doi=10.1038/nmat2992[4/21/2011 11:45:43 AM] New by nanoporous particle-supported lipid bilayers http://www.chemfeeds.com/comments.php?doi=10.1038/nmat2992 to cancer cells by nanoporous particle-supported lipid bilayers http://www.chemfeeds.com/comments.php?doi=10

Brinker, C. Jeffrey

262

Effects of hydrochloric acid treatment of TiO{sub 2} nanoparticles/nanofibers bilayer film on the photovoltaic properties of dye-sensitized solar cells  

SciTech Connect (OSTI)

Highlights: ? The TiO{sub 2} nanoparticles/TiO{sub 2} nanofibers bilayer film was fabricated for DSSC. ? The effects of HCl treated TiO{sub 2} on the performance of DSSC were investigated. ? The potential methods of improving conversion efficiency are suggested. - Abstract: The TiO{sub 2} nanoparticles/nanofibers bilayer film has been fabricated via spin coating and electrospinning followed by calcination. The TiO{sub 2} bilayer film with thickness of about 6.0 ?m is composed of anatase TiO{sub 2} phase. Dye-sensitized solar cells (DSSC) were assembled by hydrochloric acid (HCl) treated TiO{sub 2} film. The results of the photocurrent action spectra, electrochemical impedance spectroscopy (EIS), and I–V curves showed that each photovoltaic parameter of DSSC increased with the concentration of HCl increasing, and reached a maximum value and afterwards decreased. The maximum incident monochromatic photo-to-electron conversion efficiency (at 350 nm) and maximum overall conversion efficiency (?) of 0.05 M HCl treated TiO{sub 2} based DSSC were enhanced to 48.0% and 4.75%, which were respectively increased by 14% and 6.3% than those of DSSC based on untreated TiO{sub 2} film.

Song, Lixin; Du, Pingfan; Shao, Xiaoli; Cao, Houbao; Hui, Quan [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Xiong, Jie, E-mail: jxiong@zstu.edu.cn [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

2013-03-15T23:59:59.000Z

263

Magnetic properties of Ga doped cobalt ferrite: Compton scattering study  

SciTech Connect (OSTI)

We present the spin momentum density of Ga doped CoFe{sub 2}O{sub 4} at 100 K using magnetic Compton scattering. The measurement has been performed using circularly polarized synchrotron radiations of 182.65 keV at SPring8, Japan. The experimental profile is decomposed into its constituent profile to determine the spin moment at individual sites. Co atom has the maximum contribution (about 58%) in the total spin moment of the doped CoFe{sub 2}O{sub 4}.

Sharma, Arvind, E-mail: arvind.phd.swm@gmail.com; Mund, H. S.; Ahuja, B. L. [Department of Physics, University College of Science, M.L. Sukhadia University, Udaipur-313001 (India); Sahariya, Jagrati [Department of Physics, Manipal University, Jaipur-303007 (India); Itou, M.; Sakurai, Y. [Japan Synchrotron Radiation Research Institute, SPring8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2014-04-24T23:59:59.000Z

264

Controlled Chemical Doping of Semiconductor Nanocrystals Using Redox Buffers  

SciTech Connect (OSTI)

Semiconductor nanocrystal solids are attractive materials for active layers in next-generation optoelectronic devices; however, their efficient implementation has been impeded by the lack of precise control over dopant concentrations. Herein we demonstrate a chemical strategy for the controlled doping of nanocrystal solids under equilibrium conditions. Exposing lead selenide nanocrystal thin films to solutions containing varying proportions of decamethylferrocene and decamethylferrocenium incrementally and reversibly increased the carrier concentration in the solid by 2 orders of magnitude from their native values. This application of redox buffers for controlled doping provides a new method for the precise control of the majority carrier concentration in porous semiconductor thin films.

Engel, Jesse H.; Surendranath, Yogesh; Alivisatos, Paul

2013-07-09T23:59:59.000Z

265

Doping of carbon foams for use in energy storage devices  

DOE Patents [OSTI]

A polymeric foam precursor, wetted with phosphoric acid, is pyrolyzed in an inert atmosphere to produce an open-cell doped carbon foam, which is utilized as a lithium intercalation anode in a secondary, organic electrolyte battery. Tests were conducted in a cell containing an organic electrolyte and using lithium metal counter and reference electrodes, with the anode located there between. Results after charge and discharge cycling, for a total of 6 cycles, indicated a substantial increase in the energy storage capability of the phosphorus doped carbon foam relative to the undoped carbon foam, when used as a rechargeable lithium ion battery. 3 figs.

Mayer, S.T.; Pekala, R.W.; Morrison, R.L.; Kaschmitter, J.L.

1994-10-25T23:59:59.000Z

266

Doping of carbon foams for use in energy storage devices  

DOE Patents [OSTI]

A polymeric foam precursor, wetted with phosphoric acid, is pyrolyzed in an inert atmosphere to produce an open-cell doped carbon foam, which is utilized as a lithium intercalation anode in a secondary, organic electrolyte battery. Tests were conducted in a cell containing an organic electrolyte and using lithium metal counter and reference electrodes, with the anode located therebetween. Results after charge and discharge cycling, for a total of 6 cycles, indicated a substantial increase in the energy storage capability of the phosphorus doped carbon foam relative to the undoped carbon foam, when used as a rechargeable lithium ion battery.

Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Morrison, Robert L. (Modesto, CA); Kaschmitter, James L. (Pleasanton, CA)

1994-01-01T23:59:59.000Z

267

Theory of the spontaneous buckling of doped graphene  

E-Print Network [OSTI]

Graphene is a realization of an esoteric class of materials -- electronic crystalline membranes. We study the interplay between the free electrons and the two-dimensional crystal, and find that it induces a substantial effect on the elastic structure of the membrane. For the hole-doped membrane, in particular, we predict a spontaneous buckling. In addition, attenuation of elastic waves is expected, due to the effect of corrugations on the bulk modulus. These discoveries have a considerable magnitude in graphene, affecting both its mesoscopic structure, and its electrical resistivity, which has an inherent asymmetry between hole- and electron-doped graphene.

Doron Gazit

2009-03-11T23:59:59.000Z

268

Single-poly EEPROM cell with lightly doped MOS capacitors  

DOE Patents [OSTI]

An Electrically Erasable Programmable Read Only Memory (EEPROM) memory cell and a method of operation are disclosed for creating an EEPROM memory cell in a standard CMOS process. A single polysilicon layer is used in combination with lightly doped MOS capacitors. The lightly doped capacitors employed in the EEPROM memory cell can be asymmetrical in design. Asymmetrical capacitors reduce area. Further capacitance variation caused by inversion can also be reduced by using multiple control capacitors. In addition, the use of multiple tunneling capacitors provides the benefit of customized tunneling paths.

Riekels, James E. (New Hope, MN); Lucking, Thomas B. (Maple Grove, MN); Larsen, Bradley J. (Mound, MN); Gardner, Gary R. (Golden Valley, MN)

2008-05-27T23:59:59.000Z

269

Disordered electronic and magnetic systems - transition metal (Mn) and rare earth (Gd) doped amorphous group IV semiconductors (C, Si, Ge)  

E-Print Network [OSTI]

vapor deposition polycrystalline diamond ?lms. Diamonddoped (B- doped) polycrystalline diamond thin ?lms (MR?

Zeng, Li

2007-01-01T23:59:59.000Z

270

Towards an Er-doped Si nanocrystal sensitized waveguide laser the thin line between gain and loss  

E-Print Network [OSTI]

somehow be eliminated from this scheme, the fabrication of low-cost Si based Er doped optical amplifiers1 Towards an Er-doped Si nanocrystal sensitized waveguide laser ­ the thin line between gain-doped Si nanocrystal co-doped SiO2, a composite material that can potentially be fabricated using a VLSI

Polman, Albert

271

Nanosecond molecular relaxations in lipid bilayers studied by high energy resolution neutron scattering and in-situ diffraction  

E-Print Network [OSTI]

We report a high energy-resolution neutron backscattering study to investigate slow motions on nanosecond time scales in highly oriented solid supported phospholipid bilayers of the model system DMPC -d54 (deuterated 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine), hydrated with heavy water. Wave vector resolved quasi-elastic neutron scattering (QENS) is used to determine relaxation times $\\tau$, which can be associated with different molecular components, i.e., the lipid acyl chains and the interstitial water molecules in the different phases of the model membrane system. The inelastic data are complemented both by energy resolved and energy integrated in-situ diffraction. From a combined analysis of the inelastic data in the energy and time domain, the respective character of the relaxation, i.e., the exponent of the exponential decay is also determined. From this analysis we quantify two relaxation processes. We associate the fast relaxation with translational diffusion of lipid and water molecules while the slow process likely stems from collective dynamics.

Maikel C. Rheinstädter; Tilo Seydel; Tim Salditt

2006-07-20T23:59:59.000Z

272

Detection and quantification of inverse spin Hall effect from spin pumping in permalloy/normal metal bilayers.  

SciTech Connect (OSTI)

Spin pumping is a mechanism that generates spin currents from ferromagnetic resonance over macroscopic interfacial areas, thereby enabling sensitive detection of the inverse spin Hall effect that transforms spin into charge currents in nonmagnetic conductors. Here we study the spin-pumping-induced voltages due to the inverse spin Hall effect in permalloy/normal metal bilayers integrated into coplanar waveguides for different normal metals and as a function of angle of the applied magnetic field direction, as well as microwave frequency and power. We find good agreement between experimental data and a theoretical model that includes contributions from anisotropic magnetoresistance and inverse spin Hall effect. The analysis provides consistent results over a wide range of experimental conditions as long as the precise magnetization trajectory is taken into account. The spin Hall angles for Pt, Pd, Au, and Mo were determined with high precision to be 0.013 {+-} 0.002, 0.0064 {+-} 0.001, 0.0035 {+-} 0.0003, and -0.0005 {+-} 0.0001, respectively.

Mosendz, O.; Vlaminck, V.; Pearson, J. E.; Fradin, F. Y.; Bauer, G. E. W.; Bader, S. D.; Hoffmann, A.; Delft Univ. of Technology

2010-12-01T23:59:59.000Z

273

Monte Carlo Study of Strongly-Interacting Degenerate Fermions: a Model for Voltage-Biased Bilayer Graphene  

E-Print Network [OSTI]

We formulate a model of N_f=4 flavors of relativistic fermion in 2+1d in the presence of a chemical potential mu coupled to two flavor doublets with opposite sign, akin to isopsin chemical potential in QCD. This is argued to be an effective theory for low energy electronic excitations in bilayer graphene, in which an applied voltage between the layers ensures equal populations of particles on one layer and holes on the other. The model is then reformulated on a spacetime lattice using staggered fermions, and in the absence of a sign problem, simulated using an orthodox hybrid Monte Carlo algorithm. With the coupling strength chosen to be close to a quantum critical point believed to exist for N_f

Wes Armour; Simon Hands; Costas Strouthos

2013-02-07T23:59:59.000Z

274

ACCURATE EXTRACTION OF DOPING PROFILES FROM ELECTROCHEMICAL CAPACITANCE VOLTAGE MEASUREMENTS  

E-Print Network [OSTI]

. In addition, the corrected ECV data can be precisely reproduced with the process simulation software Ssuprem3 Ohrberg 1, 31860 Emmerthal, Germany 2 Dep. Solar Energy, Inst. Solid-State Physics, Leibniz University-8]. The SIMS method is in comparison to the other methods expensive and provides only the chemical doping

275

Doped tantalum oxide high K dielectric thin films  

E-Print Network [OSTI]

, it was doped with varying amounts of titanium oxide, aluminum oxide and silicon dioxide. The composite oxide films were deposited by reactive radio frequency (RF) cc-sputtering of two targets in a variety of oxygen and argon feed gas mixtures. The targets used...

Donnelly, Joseph Patrick

2000-01-01T23:59:59.000Z

276

Doped Carbon Nanotubes for Hydrogen Storage Ragaiy Zidan  

E-Print Network [OSTI]

hydrogen storage system is expected to be simple to engineer and tremendously safer. Carbon nanotubesDoped Carbon Nanotubes for Hydrogen Storage Ragaiy Zidan Savannah River Technology Center Savannah-capacity hydrogen storage material. The final product should have favorable thermodynamics and kinetics

277

Optimization of the Perimeter Doping of Ultrashallow p+  

E-Print Network [OSTI]

-Violet (UV) radiation. Surface damage can give rise to degradation of various electrical and optical of photodiode is degraded by the damage of the silicon/oxide interface at the diode perimeter region caused. An optimal doping profile is proposed for the added p-region to obtain minimal degradation of electric

Technische Universiteit Delft

278

Method of making metal-doped organic foam products  

DOE Patents [OSTI]

Organic foams having a low density and very small cell size and method for roducing same in either a metal-loaded or unloaded (nonmetal loaded) form are described. Metal-doped foams are produced by soaking a polymer gel in an aqueous solution of desired metal salt, soaking the gel successively in a solvent series of decreasing polarity to remove water from the gel and replace it with a solvent of lower polarity with each successive solvent in the series being miscible with the solvents on each side and being saturated with the desired metal salt, and removing the last of the solvents from the gel to produce the desired metal-doped foam having desired density cell size, and metal loading. The unloaded or metal-doped foams can be utilized in a variety of applications requiring low density, small cell size foam. For example, rubidium-doped foam made in accordance with the invention has utility in special applications, such as in x-ray lasers.

Rinde, James A. (Livermore, CA)

1981-01-01T23:59:59.000Z

279

High phosphorous doped germanium: Dopant diffusion and modeling  

E-Print Network [OSTI]

The in situ n-type doping of Ge thin films epitaxial grown on Si substrates is limited to 1?×?10[superscript 19]?cm[superscript ?3] by the phosphorous out-diffusion during growth at 600?°C. By studying the phosphorous ...

Cai, Yan

280

Ultralow Thermal Conductivity of Isotope-Doped Silicon Nanowires  

E-Print Network [OSTI]

conductivity of SiNWs is about 2 orders of magnitude smaller than that of bulk crystals.18,19 The low thermal conductivity (0.05 W/m K) found in layered materials.22 So it is indispensable to reduce the thermal conUltralow Thermal Conductivity of Isotope-Doped Silicon Nanowires Nuo Yang, Gang Zhang,*, and Baowen

Li, Baowen

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Macro- and microscopic properties of strontium doped indium oxide  

SciTech Connect (OSTI)

Solid state synthesis and physical mechanisms of electrical conductivity variation in polycrystalline, strontium doped indium oxide In{sub 2}O{sub 3}:(SrO){sub x} were investigated for materials with different doping levels at different temperatures (T?=?20–300?°C) and ambient atmosphere content including humidity and low pressure. Gas sensing ability of these compounds as well as the sample resistance appeared to increase by 4 and 8 orders of the magnitude, respectively, with the doping level increase from zero up to x?=?10%. The conductance variation due to doping is explained by two mechanisms: acceptor-like electrical activity of Sr as a point defect and appearance of an additional phase of SrIn{sub 2}O{sub 4}. An unusual property of high level (x?=?10%) doped samples is a possibility of extraordinarily large and fast oxygen exchange with ambient atmosphere at not very high temperatures (100–200?°C). This peculiarity is explained by friable structure of crystallite surface. Friable structure provides relatively fast transition of samples from high to low resistive state at the expense of high conductance of the near surface layer of the grains. Microscopic study of the electro-diffusion process at the surface of oxygen deficient samples allowed estimation of the diffusion coefficient of oxygen vacancies in the friable surface layer at room temperature as 3?×?10{sup ?13}?cm{sup 2}/s, which is by one order of the magnitude smaller than that known for amorphous indium oxide films.

Nikolaenko, Y. M.; Kuzovlev, Y. E.; Medvedev, Y. V.; Mezin, N. I. [Donetsk Institute for Physics and Technology, National Academy of Sciences of Ukraine, 83114 Donetsk (Ukraine); Fasel, C.; Gurlo, A.; Schlicker, L.; Bayer, T. J. M.; Genenko, Y. A. [Institute of Materials Science, Darmstadt University of Technology, 64287 Darmstadt (Germany)

2014-07-28T23:59:59.000Z

282

Concentration efficiency of doping in phosphors: Investigation of the copper-and aluminum-doped zinc sulfide  

E-Print Network [OSTI]

Concentration efficiency of doping in phosphors: Investigation of the copper- and aluminum October 2003 We studied the effect of dopant concentration in ZnS:Cu, Al phosphor. Photoluminescent PL intensity of the chemically etched phosphor particles increased up to 140%, which proved the existence

Grujicic, Mica

283

The effect of interface oxygen content on magnetoelectric effect of epitaxial La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/BaTiO{sub 3} bilayer  

SciTech Connect (OSTI)

The epitaxial La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/BaTiO{sub 3} (LSMO/BTO) bilayer films are grown on (001) oriented LaAlO{sub 3} substrate by pulsed laser deposition technique. The oxygen-rich interface is obtained through in-situ annealing process in oxygen, and the oxygen-deficient interface is obtained without the annealing process. The results show that the ferromagnetic properties of the LSMO film and the magnetoelectric effect (ME) of the bilayer films strongly correlate to the oxygen content at the interface of LSMO/BTO. The saturated magnetization and the ME voltage coefficient of the oxygen-rich bilayer film are higher than that of oxygen-deficient one. It suggests a more effective ME coupling at the LSMO/BTO interface, which are generated through not only the interface strain but also the spin polarized carriers.

Tingxian, Li, E-mail: wxlltx@126.com [College of Physics and Electrical Engineering, Anyang Normal University, Anyang 455002 (China); Kuoshe, Li [National Engineering Research Central for Rare Earth Materials, General Research Institute for Nonferrous Metals, The Grirem Advanced materials Co. Ltd., Beijing 100088 (China)

2014-01-28T23:59:59.000Z

284

Excellent Passivation and Low Reflectivity Al2O3/TiO2 Bilayer Coatings for n-Wafer Silicon Solar Cells: Preprint  

SciTech Connect (OSTI)

A bilayer coating of Al2O3 and TiO2 is used to simultaneously achieve excellent passivation and low reflectivity on p-type silicon. This coating is targeted for achieving high efficiency n-wafer Si solar cells, where both passivation and anti-reflection (AR) are needed at the front-side p-type emitter. It could also be valuable for front-side passivation and AR of rear-emitter and interdigitated back contact p-wafer cells. We achieve high minority carrier lifetimes {approx}1 ms, as well as a nearly 2% decrease in absolute reflectivity, as compared to a standard silicon nitride AR coating.

Lee, B. G.; Skarp, J.; Malinen, V.; Li, S.; Choi, S.; Branz, H. M.

2012-06-01T23:59:59.000Z

285

Polarization doping and the efficiency of III-nitride optoelectronic devices  

SciTech Connect (OSTI)

The intrinsic polarization is generally considered a nuisance in III-nitride devices, but recent studies have shown that it can be used to enhance p- and n-type conductivity and even to replace impurity doping. We show by numerical simulations that polarization-doped light-emitting diode (LED) structures have a significant performance advantage over conventional impurity-doped LED structures. Our results indicate that polarization doping decreases electric fields inside the active region and potential barriers in the depletion region, as well as the magnitude of the quantum-confined Stark effect. The simulations also predict at least an order of magnitude increase in the current density corresponding to the maximum efficiency (i.e., smaller droop) as compared to impurity-doped structures. The obtained high doping concentrations could also enable, e.g., fabrication of III-N resonant tunneling diodes and improved ohmic contacts.

Kivisaari, Pyry; Oksanen, Jani; Tulkki, Jukka [Department of Biomedical Engineering and Computational Science, Aalto University, P.O. Box 12200, FI-00076 Aalto (Finland)] [Department of Biomedical Engineering and Computational Science, Aalto University, P.O. Box 12200, FI-00076 Aalto (Finland)

2013-11-18T23:59:59.000Z

286

Control of work function of graphene by plasma assisted nitrogen doping  

SciTech Connect (OSTI)

Nitrogen doping is expected to provide several intriguing properties to graphene. Nitrogen plasma treatment to defect-free and defective highly oriented pyrolytic graphite (HOPG) samples causes doping of nitrogen atom into the graphene layer. Nitrogen atoms are initially doped at a graphitic site (inside the graphene) for the defect-free HOPG, while doping to a pyridinic or a pyrrolic site (edge of the graphene) is dominant for the defective HOPG. The work function of graphene correlates strongly with the site and amount of doped nitrogen. Nitrogen atoms doped at a graphitic site lower the work function, while nitrogen atoms at a pyridinic or a pyrrolic site increase the work function. Control of plasma treatment time and the amount of initial defect could change the work function of graphite from 4.3?eV to 5.4?eV, which would open a way to tailor the nature of graphene for various industrial applications.

Akada, Keishi; Terasawa, Tomo-o; Imamura, Gaku; Obata, Seiji; Saiki, Koichiro, E-mail: saiki@k.u-tokyo.ac.jp [Department of Complexity Science and Engineering, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561 (Japan)

2014-03-31T23:59:59.000Z

287

Electrochemical hydrogen termination of boron-doped diamond  

SciTech Connect (OSTI)

Boron-doped diamond is a promising transducer material for numerous devices which are designed for contact with electrolytes. For optimized electron transfer the surface of diamond needs to be hydrogen terminated. Up to now H-termination of diamond is done by plasma chemical vapor deposition techniques. In this paper, we show that boron-doped diamond can be H-terminated electrochemically by applying negative voltages in acidic solutions. Electrochemical H-termination generates a clean surface with virtually no carbon-oxygen bonds (x-ray photoelectron spectroscopy), a reduced electron affinity (scanning electron microscopy), a highly hydrophobic surface (water contact angle), and a fast electron exchange with Fe(CN){sub 6}{sup -3/-4} (cyclic voltammetry).

Hoffmann, Rene; Kriele, Armin; Obloh, Harald; Hees, Jakob; Wolfer, Marco; Smirnov, Waldemar; Yang Nianjun; Nebel, Christoph E. [Fraunhofer Institute for Applied Solid State Physics (IAF), Tullastrasse 72, Freiburg 79108 (Germany)

2010-08-02T23:59:59.000Z

288

Doped surfaces in one sun, point-contact solar cells  

SciTech Connect (OSTI)

This letter reports two new types of large-area (>8.5 cm/sup 2/), backside, point-contact solar cells with doped surfaces, designed for use in unconcentrated sunlight. One type was fabricated on an intrinsic substrate with an optimized phosphorus diffusion on the sunward surface. The apertured-area efficiency was independently measured to be 22.3% at 1 sun (0.100 W/cm/sup 2/), 25 /sup 0/C, the highest reported for a silicon solar cell. The other type is constructed on a doped substrate, and has an apertured-area efficiency of 20.9%, the highest reported for a point-contact solar cell with a base in low-level injection. Both cells have record open-circuit voltages above 700 mV.

King, R.R.; Sinton, R.A.; Swanson, R.M.

1989-04-10T23:59:59.000Z

289

Imaging doped silicon test structures using low energy electron microscopy.  

SciTech Connect (OSTI)

This document is the final SAND Report for the LDRD Project 105877 - 'Novel Diagnostic for Advanced Measurements of Semiconductor Devices Exposed to Adverse Environments' - funded through the Nanoscience to Microsystems investment area. Along with the continuous decrease in the feature size of semiconductor device structures comes a growing need for inspection tools with high spatial resolution and high sample throughput. Ideally, such tools should be able to characterize both the surface morphology and local conductivity associated with the structures. The imaging capabilities and wide availability of scanning electron microscopes (SEMs) make them an obvious choice for imaging device structures. Dopant contrast from pn junctions using secondary electrons in the SEM was first reported in 1967 and more recently starting in the mid-1990s. However, the serial acquisition process associated with scanning techniques places limits on the sample throughput. Significantly improved throughput is possible with the use of a parallel imaging scheme such as that found in photoelectron emission microscopy (PEEM) and low energy electron microscopy (LEEM). The application of PEEM and LEEM to device structures relies on contrast mechanisms that distinguish differences in dopant type and concentration. Interestingly, one of the first applications of PEEM was a study of the doping of semiconductors, which showed that the PEEM contrast was very sensitive to the doping level and that dopant concentrations as low as 10{sup 16} cm{sup -3} could be detected. More recent PEEM investigations of Schottky contacts were reported in the late 1990s by Giesen et al., followed by a series of papers in the early 2000s addressing doping contrast in PEEM by Ballarotto and co-workers and Frank and co-workers. In contrast to PEEM, comparatively little has been done to identify contrast mechanisms and assess the capabilities of LEEM for imaging semiconductor device strictures. The one exception is the work of Mankos et al., who evaluated the impact of high-throughput requirements on the LEEM designs and demonstrated new applications of imaging modes with a tilted electron beam. To assess its potential as a semiconductor device imaging tool and to identify contrast mechanisms, we used LEEM to investigate doped Si test structures. In section 2, Imaging Oxide-Covered Doped Si Structures Using LEEM, we show that the LEEM technique is able to provide reasonably high contrast images across lateral pn junctions. The observed contrast is attributed to a work function difference ({Delta}{phi}) between the p- and n-type regions. However, because the doped regions were buried under a thermal oxide ({approx}3.5 nm thick), e-beam charging during imaging prevented quantitative measurements of {Delta}{phi}. As part of this project, we also investigated a series of similar test structures in which the thermal oxide was removed by a chemical etch. With the oxide removed, we obtained intensity-versus-voltage (I-V) curves through the transition from mirror to LEEM mode and determined the relative positions of the vacuum cutoffs for the differently doped regions. Although the details are not discussed in this report, the relative position in voltage of the vacuum cutoffs are a direct measure of the work function difference ({Delta}{phi}) between the p- and n-doped regions.

Nakakura, Craig Yoshimi; Anderson, Meredith Lynn; Kellogg, Gary Lee

2010-01-01T23:59:59.000Z

290

High gain photoconductive semiconductor switch having tailored doping profile zones  

DOE Patents [OSTI]

A photoconductive semiconductor switch with tailored doping profile zones beneath and extending laterally from the electrical contacts to the device. The zones are of sufficient depth and lateral extent to isolate the contacts from damage caused by the high current filaments that are created in the device when it is turned on. The zones may be formed by etching depressions into the substrate, then conducting epitaxial regrowth in the depressions with material of the desired doping profile. They may be formed by surface epitaxy. They may also be formed by deep diffusion processes. The zones act to reduce the energy density at the contacts by suppressing collective impact ionization and formation of filaments near the contact and by reducing current intensity at the contact through enhanced current spreading within the zones.

Baca, Albert G. (Albuquerque, NM); Loubriel, Guillermo M. (Albuquerque, NM); Mar, Alan (Albuquerque, NM); Zutavern, Fred J (Albuquerque, NM); Hjalmarson, Harold P. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM); Zipperian, Thomas E. (Edgewood, NM); O'Malley, Martin W. (Edgewood, NM); Helgeson, Wesley D. (Albuquerque, NM); Denison, Gary J. (Sandia Park, NM); Brown, Darwin J. (Albuquerque, NM); Sullivan, Charles T. (Albuquerque, NM); Hou, Hong Q. (Albuquerque, NM)

2001-01-01T23:59:59.000Z

291

Direct visualization of atomically precise nitrogen-doped graphene nanoribbons  

SciTech Connect (OSTI)

We have fabricated atomically precise nitrogen-doped chevron-type graphene nanoribbons by using the on-surface synthesis technique combined with the nitrogen substitution of the precursors. Scanning tunneling microscopy and spectroscopy indicate that the well-defined nanoribbons tend to align with the neighbors side-by-side with a band gap of 1.02?eV, which is in good agreement with the density functional theory calculation result. The influence of the high precursor coverage on the quality of the nanoribbons is also studied. We find that graphene nanoribbons with sufficient aspect ratios can only be fabricated at sub-monolayer precursor coverage. This work provides a way to construct atomically precise nitrogen-doped graphene nanoribbons.

Zhang, Yi; Zhang, Yanfang; Li, Geng; Lu, Jianchen; Du, Shixuan, E-mail: sxdu@iphy.ac.cn, E-mail: feng@mpip-mainz.mpg.de; Gao, Hong-Jun [Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China); Lin, Xiao [University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100049 (China); Berger, Reinhard; Feng, Xinliang, E-mail: sxdu@iphy.ac.cn, E-mail: feng@mpip-mainz.mpg.de; Müllen, Klaus [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany)

2014-07-14T23:59:59.000Z

292

OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES  

SciTech Connect (OSTI)

This chapter provides an overview of some recent research activities on the study of optical and dynamic properties of semiconductor nanomaterials. The emphasis is on unique aspects of these properties in nanostructures as compared to bulk materials. Linear, including absorption and luminescence, and nonlinear optical as well as dynamic properties of semiconductor nanoparticles are discussed with focus on their dependence on particle size, shape, and surface characteristics. Both doped and undoped semiconductor nanomaterials are highlighted and contrasted to illustrate the use of doping to effectively alter and probe nanomaterial properties. Some emerging applications of optical nanomaterials are discussed towards the end of the chapter, including solar energy conversion, optical sensing of chemicals and biochemicals, solid state lighting, photocatalysis, and photoelectrochemistry.

Grant, C D; Zhang, J Z

2007-09-28T23:59:59.000Z

293

Influence of damping constant on inverse spin hall voltage of La{sub 0.7}Sr{sub 0.3}MnO{sub 3}(x)/platinum bilayers  

SciTech Connect (OSTI)

Pure spin transport via spin pumping in the condition of ferromagnetic resonance can be transformed to charge current in the ferromagnetic/paramagnetic bilayer systems, based on inverse spin Hall effect (ISHE). Here, we explore La{sub 0.7}Sr{sub 0.3}MnO(x)/Pt(5.5?nm) [x?=?10 to 65 nm] bilayers to investigate the influence of damping constant on spin pumping efficiency. The results show that the ISHE voltage depend on the damping constant of magnetic moment, suggesting that the precession energy tansferred to lattice/electron of normal metal is a key parameter to control the magnitude of spin current.

Luo, G. Y. [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Chang, C. R. [Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Lin, J. G., E-mail: jglin@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China)

2014-05-07T23:59:59.000Z

294

INTERACTION OF DEFECTS IN CdTe-CRYSTALS HEAVILY DOPED WITH CHLORINE  

E-Print Network [OSTI]

ClTe) and (VCd 2 ClTe)] form, but larger clusters as well. Thus, the compensation process in Cl doped CdTe, PAGE In order to clarify the mechanism of compensation in semi-insulating crystals of CdTe doped.1051/rphysap:01977001202023500 #12;236 FIG. 1. - Photoluminescence spectra of In and Cl doped CdTe. ND = 10 17

Paris-Sud XI, Université de

295

Synthesis of mesoporous NiO doped TiO{sub 2} submicrosphere via spray hydrolysis  

SciTech Connect (OSTI)

NiO doped TiO{sub 2} submicrosphere have been prepared via spray hydrolysis. The doping concentration has been varied form 2 wt% to 15 wt%. Morphology of the submicrospheres has been investigated using small-angle neutron scattering and scanning electron microscopy. Elemental analysis has been carried out by energy dispersive X-ray analysis which confirms the doping concentrations. The mesopores in submicrospheres possess cylindrical morphology.

Bahadur, J.; Sen, D.; Prakash, J.; Singh, Ripandeep; Paul, B.; Mazumder, S.; Sathiyamoorthy, D. [Solid State Physics Division Bhabha Atomic Research Centre, Mumbai, 400085, India (India); Powder Metallurgy Division Bhabha Atomic Research Centre, Mumbai, 400085 (India); Solid State Physics, Division Bhabha Atomic Research Centre, Mumbai, 400085 (India); Materials Processing Division Bhabha Atomic Research Centre, Mumbai, 400085 (India); Solid State Physics Division Bhabha Atomic Research Centre, Mumbai, 400085 (India); Powder Metallurgy Division Bhabha Atomic Research Centre, Mumbai, 400085 (India)

2012-06-05T23:59:59.000Z

296

Visible light photocatalytic activity in nitrogen-doped TiO{sub 2} nanobelts  

SciTech Connect (OSTI)

We present a comprehensive experimental and theoretical study of the electronic properties and photocatalytic activity of nitrogen-doped anatase TiO{sub 2} nanobelts. UV-visible spectra show enhanced absorption in the visible light range for nitrogen-doped nanobelts compared to the pristine sample. The nitrogen-doped nanobelts exhibit improved photocatalytic activity compared to the pristine sample upon visible light irradiation. Furthermore, the incorporation of nitrogen introduces localized states in the band gap.

De Nyago Tafen; Lewis, James P. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Wang Jin; Wu Nianqiang [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, West Virginia 26506 (United States)

2009-03-02T23:59:59.000Z

297

Fabrication and characterization of modulation-doped-field-effect-transistors with antidot-patterned passivation layers  

E-Print Network [OSTI]

layer with 1 1017 cm 3 Si doping, 50 nm Al0.3Ga0.7As spacer with 1 1018 cm 3 Si doping, 15 nm undoped Al0.3Ga0.7As spacer, 500 nm un- doped GaAs channel layer, 20 periods of 5/5 nm GaAs/ Al. For the demonstration of the internal gate patterning, two types of MODFET's with the same overall gate dimensions

Hwang, Sung Woo

298

Method for measuring the drift mobility in doped semiconductors  

DOE Patents [OSTI]

A method for measuring the drift mobility of majority carriers in semiconductors consists of measuring the current transient in a Schottky-barrier device following the termination of a forward bias pulse. An example is given using an amorphous silicon hydrogenated material doped with 0.2% phosphorous. The method is particularly useful with material in which the dielectric relaxation time is shorter than the carrier transit time. It is particularly useful in material useful in solar cells.

Crandall, Richard S. (Princeton, NJ)

1982-01-01T23:59:59.000Z

299

Method for measuring the drift mobility in doped semiconductors  

DOE Patents [OSTI]

A method for measuring the drift mobility of majority carriers in semiconductors consists of measuring the current transient in a Schottky-barrier device following the termination of a forward bias pulse. An example is given using an amorphous silicon hydrogenated material doped with 0.2% phosphorus. The method is particularly useful with material in which the dielectric relaxation time is shorter than the carrier transit time. It is particularly useful in material useful in solar cells. 10 figs.

Crandall, R.S.

1982-03-09T23:59:59.000Z

300

Kohn anomalies and non-adiabaticity in doped carbon nanotubes  

E-Print Network [OSTI]

The high-frequency Raman-active phonon modes of metallic single-walled carbon nanotubes (SWNTs) are thought to be characterized by Kohn anomalies (KAs), which are expected to be modified by the doping-induced tuning of the Fermi energy level $\\epsilon_F$, obtained through the intercalation of SWNTs with alkali atoms or by the application of a gate potential. We present a Density-Functional Theory (DFT) study of the phonon properties of a (9,9) metallic SWNT as a function of electronic doping. For such study, we use, as in standard DFT calculations of vibrational properties, the Born-Oppenheimer (BO) approximation. We also develop an analytical model capable of reproducing and interpreting our DFT results. Both DFT calculations and this model predict, for increasing doping levels, a series of EPC-induced KAs in the vibrational mode parallel to the tube axis at the $\\mathbf\\Gamma$ point of the Brillouin zone, usually indicated in Raman spectroscopy as the $G^-$ peak. Such KAs would arise each time a new conduction band is populated. However, we show that they are an artifact of the BO approximation. The inclusion of non-adiabatic (NA) effects dramatically affects the results, predicting KAs at $\\mathbf\\Gamma$ only when $\\epsilon_F$ is close to a band crossing $E_{X}$. For each band crossing a double KA occurs for $\\epsilon_F=E_{X}\\pm \\hbar\\omega/2$, where $\\hbar\\omega$ is the phonon energy. In particular, for a 1.2 $nm$ metallic nanotube, we predict a KA to occur in the so-called $G^-$ peak at a doping level of about $N_{el}/C=\\pm 0.0015$ atom ($\\epsilon_F\\approx \\pm 0.1 ~eV$). Furthermore, we predict that the Raman linewidth of the $G^-$ peak significantly decreases for $|\\epsilon_F| \\geq \\hbar\\omega/2$.

Nicolas Caudal; A. Marco Saitta; Michele Lazzeri; Francesco Mauri

2007-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.


301

Self-doped microphase separated block copolymer electrolyte  

DOE Patents [OSTI]

A polymer electrolyte includes a self-doped microphase separated block copolymer including at least one ionically conductive block and at least one second block that is immiscible in the ionically conductive block, an anion immobilized on the polymer electrolyte and a cationic species. The ionically conductive block provides a continuous ionically conductive pathway through the electrolyte. The electrolyte may be used as an electrolyte in an electrochemical cell.

Mayes, Anne M. (Waltham, MA); Sadoway, Donald R. (Waltham, MA); Banerjee, Pallab (Boston, MA); Soo, Philip (Cambridge, MA); Huang, Biying (Cambridge, MA)

2002-01-01T23:59:59.000Z

302

Non-aqueous solution preparation of doped and undoped lixmnyoz  

DOE Patents [OSTI]

A method for generation of phase-pure doped and undoped Li.sub.x Mn.sub.y O.sub.z precursors. The method of this invention uses organic solutions instead of aqueous solutions or nonsolution ball milling of dry powders to produce phase-pure precursors. These precursors can be used as cathodes for lithium-polymer electrolyte batteries. Dopants may be homogeneously incorporated to alter the characteristics of the powder.

Boyle, Timothy J. (5801 Eubank, N.E., Apt. #97, Albuquerque, NM 87111); Voigt, James A. (187 Aaramar La., Corrales, NM 87048)

1997-01-01T23:59:59.000Z

303

Optical Response of Shocked Cerium-Doped Lutetium Oxyorthosilicate  

SciTech Connect (OSTI)

Shock experiments were performed in order to characterize the triboluminescent signature of cerium-doped lutetium oxyorthosilicate (LSO:Ce). This material shows prompt, nano-second timescale light emission when driven by explosive detonation. When properly applied to a surface, it may be used as a shock arrival sensor, and also for imaging the propagation of a shock front. Triboluminescent rise times, spectral content, and spatial resolution measurements are presented.

G. D. Stevens

2003-03-01T23:59:59.000Z

304

Ca2+-Doped CeBr3 Scintillating Materials  

SciTech Connect (OSTI)

Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was used as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were studied using the density functional theory within the generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

Guss, Paul [NSTec; Foster, Michael E. [SNL; Wong, Bryan M. [SNL; Doty, F. Patrick [SNL; Shah, Kanai [RMD; Squillante, Michael R. [RMD; Shirwadkar, Urmila [RMD; Hawrami, Rastgo [RMD; Tower, Josh [RMD; Yuan, Ding [NSTec

2014-01-01T23:59:59.000Z

305

Plasmons in inhomogeneously doped neutral and charged graphene nanodisks  

SciTech Connect (OSTI)

We study plasmons in graphene nanodisks including the effect of inhomogeneity in the distribution of the doping charge. Specifically, we discuss the following two configurations: charged disks containing a fixed amount of additional carriers, which are self-consistently distributed along the surface to produce a uniform DC potential; and neutral disks exposed to a neighboring external point charge. A suitable finite-element method is elaborated to compute the charge density associated with the plasmons in the electrostatic limit. For charged disks, we find dipolar plasmons similar to those of uniformly doped graphene structures, in which the plasmon induced charge piles up near the edges. In contrast, in neutral disks placed near an external point charge, plasmons are strongly localized away from the edges. Surprisingly, a single external electron is enough to trap plasmons. The disks also display axially symmetric dark-plasmons, which can be excited through external illumination by coupling them to a neighboring metallic element. Our results have practical relevance for graphene nanophotonics under inhomogeneous doping conditions.

Silveiro, Iván [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Javier García de Abajo, F., E-mail: javier.garciadeabajo@icfo.es [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys, 23, 08010 Barcelona (Spain)

2014-03-31T23:59:59.000Z

306

Theory of nitrogen doping of carbon nanoribbons: Edge effects  

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

Nitrogen doping of a carbon nanoribbon is profoundly affected by its one-dimensional character, symmetry, and interaction with edge states. Using state-of-the-art ab initio calculations, including hybrid exact-exchange density functional theory, we find that, for N-doped zigzag ribbons, the electronic properties are strongly dependent upon sublattice effects due to the non-equivalence of the two sublattices. For armchair ribbons, N-doping effects are different depending upon the ribbon family: for families 2 and 0, the N-induced levels are in the conduction band, while for family 1 the N levels are in the gap. In zigzag nanoribbons, nitrogen close to the edge is a deep center, while in armchair nanoribbons its behavior is close to an effective-mass-like donor with the ionization energy dependent on the value of the band gap. In chiral nanoribbons, we find strong dependence of the impurity level and formation energy upon the edge position of the dopant, while such site-specificity is not manifested in the magnitude of the magnetization.

Jiang, Jie [North Carolina State Univ., Raleigh, NC (United States) and Yale Univ, New Haven, CT (United States); Turnbull, Joseph [North Carolina State Univ., Raleigh, NC (United States); Lu, Wenchang [North Carolina State Univ., Raleigh, NC (United States) and Oak Ridge National Lab., TN (United States); Boguslawski, Piotr [North Carolina State Univ., Raleigh, NC (United States) and Institute of Physics, Warsaw, and Bydgoszcz (Poland); Bernholc, J. [North Carolina State Univ., Raleigh, NC (United States) and Oak Ridge National Lab., TN (United States)

2012-01-05T23:59:59.000Z

307

Supercontinuum generation and lasing in thulium doped tellurite microstructured fibers  

SciTech Connect (OSTI)

We report supercontinuum (SC) generation in Tm{sup 3+} doped tellurite microstructured fibers (TMFs) pumped by a 1.56??m femtosecond fiber laser. In comparison with SC generation in undoped TMFs, the SC spectral bandwidth and the spectral intensity in the wavelength region of >1.9??m are evidently enlarged in Tm{sup 3+} doped TMFs owing to the contribution of the combination of linear gain of Tm{sup 3+} and the nonlinear optical effects to spectral broadening. Furthermore, a transition from SC generation to 1.887??m lasing (Tm{sup 3+}: {sup 3}F{sub 4}?{sup 3}H{sub 6} transition) is observed in Tm{sup 3+} doped TMFs by varying the pulse width of the pump laser from 0.29 to 3.47 ps, which gives the evidence of the above spectral broadening mechanism. This is the first observation of the transition from SC generation to lasing, to the best of our knowledge.

Jia, Zhi-Xu; Liu, Lai; Yao, Chuan-Fei; Qin, Guan-Shi, E-mail: qings@jlu.edu.cn; Qin, Wei-Ping, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Ohishi, Yasutake [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

2014-02-14T23:59:59.000Z

308

anti-doping agency criteria: Topics by E-print Network  

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

Health Biostatistics Seminars Biology and Medicine Websites Summary: and Statistics, McGill University The statistical setting of decision limits for anti-doping tests...

309

Photoreduction of metal nanostructures on periodically proton exchanged MgO-doped lithium niobate crystals  

SciTech Connect (OSTI)

Local reactivity on periodically proton exchanged lithium niobate (PPE:LN) surfaces is a promising route for the fabrication of regularly spaced nanostructures. Here, using MgO-doped PPE:LN templates, we investigate the influence of the doping on the nanostructure formation as a function of the proton exchange (PE) depth. The deposition is found to occur preferentially along the boundary between MgO-doped LN and the PE region when the PE depth is at least 1.73 ?m, however, for shallower depths, deposition occurs across the entire PE region. The results are found to be consistent with an increased photoconductivity of the MgO-doped LN.

Balobaid, Laila [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)] [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Craig Carville, N.; Collins, Liam; Rodriguez, Brian J. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Manzo, Michele; Gallo, Katia [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)] [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)

2013-10-28T23:59:59.000Z

310

Growth study and photocatalytic properties of Co-doped tungsten oxide mesocrystals  

SciTech Connect (OSTI)

Cobalt-doped tungsten oxide mesocrystals with different morphologies have been successfully generated using a solvothermal method with tungsten hexachloride and cobalt chloride salts as precursors. The resulting mesocrystals were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmet-Teller analysis of nitrogen sorptometer, and UV-vis diffuse reflectance spectroscopy. The photocatalytic properties of the cobalt-doped tungsten oxide mesocrystals were evaluated on the basis of their ability to degrade methyl orange in an aqueous solution under simulated sunlight irradiation. Results showed that the cobalt doping had obvious effect on the morphologies of the final products, and lenticular and blocky cobalt-doped tungsten oxide mesocrystals could be obtained with 1.0 wt.% and 2.0 wt.% cobalt doping, respectively. The cobalt-doped tungsten oxides exhibited superior photocatalytic activities to that of the undoped tungsten oxide. - Graphical abstract: Schematic illustrations of the growth of the bundled nanowires, lenticular mesocrystals, and blocky mesocrystals. Highlights: Black-Right-Pointing-Pointer Co-doped W{sub 18}O{sub 49} mesocrystals were synthesized using a solvothermal method. Black-Right-Pointing-Pointer The Co doping has obvious effect on the morphology of the final mesocrystals. Black-Right-Pointing-Pointer The Co-doped W{sub 18}O{sub 49} exhibited superior photocatalytic activity to the undoped W{sub 18}O{sub 49}.

Sun, Shibin [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China) [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China); College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China); Chang, Xueting, E-mail: xuetingchang@yahoo.cn [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China)] [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China); Li, Zhenjiang [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)

2012-11-15T23:59:59.000Z

311

E-Print Network 3.0 - antimony-doped tin oxide Sample Search...  

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

Summary: the physical and mechanical properties of silver and antimony doped PbTe thermoelectric materials Implications... catalyst based on palladium on zinc oxide...

312

E-Print Network 3.0 - apical oxygen doping Sample Search Results  

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

Collection: Materials Science ; Chemistry 45 Theoretical search for spintronic and electrochromic device materials based on Li-intercalated transition-metal-doped anatase TiO2...

313

Doping optimization of polypyrrole with toluenesulfonic acid using Box-Behnken design  

SciTech Connect (OSTI)

A three-level Box-Behnken design was employed in doping optimization of polypyrrole with toluenesulfonic acid (TSA-doped PPy). The material was synthesized via chemical oxidative polymerization using pyrrole, toluenesulfonic acid (TSA) and ammonium persulfate (APS) as monomer, dopant and oxidant, respectively. The critical factors selected for this study were concentration of dopant, molar ratio between dopant to monomer (pyrrole) and concentration of oxidant. Obtaining adequate doping level of TSA-doped PPy is crucial because it affects the charge carriers for doped PPy and usually be responsible for electronic mobility along polymeric chain. Furthermore, the doping level also affects other properties such as electrical and thermal conductivity. Doping level was calculated using elemental analysis. SEM images shows that the prepared TSA-doped PPy particles are spherical in shape with the diameters of about. The range of nanoparticles size is around 80-100 nm. The statistical analysis based on a Box–Behnken design showed that 0.01 mol of TSA, 1:1 mole ratio TSA to pyrrole and 0.25 M APS were the optimum conditions for sufficient doping level.

Syed Draman, Sarifah Fauziah; Daik, Rusli [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); El-Sheikh, Said M. [Nanostructured Materials and Nanotechnology Division, Central Metallurgical Research and Development Institute,11421 Cairo (Egypt); Latif, Famiza Abdul [Faculty of Applied Sciences, Universiti Teknologi MARA Malaysia 40450 Shah Alam, Selangor (Malaysia)

2013-11-27T23:59:59.000Z

314

E-Print Network 3.0 - amorphous semiconductors doped Sample Search...  

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

properties can be changed... by "doping" the material with either n- type dopants (Phosphorous) or ... Source: Palermo, Sam - Department of Electrical and Computer Engineering,...

315

E-Print Network 3.0 - acid doped ab-pbi Sample Search Results  

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

Wei, Kunlin Wang... wafer followed by acid infiltration. KEYWORDS: Carbon nanotube, solar cell, acid doping, photoelectro... , we report the achievement of high performance...

316

Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers  

DOE Patents [OSTI]

A method for doping semiconductors used for far infrared lasers with non-hydrogenic acceptors having binding energies larger than the energy of the laser photons. Doping of germanium or silicon crystals with beryllium, zinc or copper. A far infrared laser comprising germanium crystals doped with double or triple acceptor dopants permitting the doped laser to be tuned continuously from 1 to 4 terahertz and to operate in continuous mode. A method for operating semiconductor hole population inversion lasers with a closed cycle refrigerator.

Haller, Eugene E. (Berkeley, CA); Brundermann, Erik (Berlin, DE)

2000-01-01T23:59:59.000Z

317

Bismuth-doped optical fibres: A new breakthrough in near-IR lasing media  

SciTech Connect (OSTI)

Recent results demonstrate that bismuth-doped optical fibres have considerable potential as near-IR active lasing media. This paper examines bismuth-doped fibres intended for the fabrication of fibre lasers and optical amplifiers and reviews recent results on the luminescence properties of various types of bismuth-doped fibres and the performance of bismuth-doped fibre lasers and optical amplifiers for the spectral range 1150 - 1550 nm. Problems are discussed that have yet to be solved in order to improve the efficiency of the bismuth lasers and optical amplifiers. (optical fibres, lasers and amplifiers. properties and applications)

Dianov, Evgenii M [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

2012-09-30T23:59:59.000Z

318

SU-8 doped and encapsulated n-type graphene nanomesh with high air stability  

SciTech Connect (OSTI)

N-type doping of graphene with long-term chemical stability in air represents a significant challenge for practical application of graphene electronics. This paper reports a reversible doping method to achieve highly stable n-type graphene nanomeshes, in which the SU-8 photoresist simultaneously serves as an effective electron dopant and an excellent encapsulating layer. The chemically stable n-type characteristics of the SU-8 doped graphene were evaluated in air using their Raman spectra, electrical transport properties, and electronic band structures. The SU-8 doping does minimum damage to the hexagonal carbon lattice of graphene and is completely reversible by removing the uncrosslinked SU-8 resist.

Al-Mumen, Haider [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States) [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Electrical Engineering, University of Babylon, Babylon (Iraq); Dong, Lixin; Li, Wen, E-mail: wenli@egr.msu.edu [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)] [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)

2013-12-02T23:59:59.000Z

319

Electrically actuatable doped polymer flakes and electrically addressable optical devices using suspensions of doped polymer flakes in a fluid host  

DOE Patents [OSTI]

Doped electrically actuatable (electrically addressable or switchable) polymer flakes have enhanced and controllable electric field induced motion by virtue of doping a polymer material that functions as the base flake matrix with either a distribution of insoluble dopant particles or a dopant material that is completely soluble in the base flake matrix. The base flake matrix may be a polymer liquid crystal material, and the dopants generally have higher dielectric permittivity and/or conductivity than the electrically actuatable polymer base flake matrix. The dopant distribution within the base flake matrix may be either homogeneous or non-homogeneous. In the latter case, the non-homogeneous distribution of dopant provides a dielectric permittivity and/or conductivity gradient within the body of the flakes. The dopant can also be a carbon-containing material (either soluble or insoluble in the base flake matrix) that absorbs light so as to reduce the unpolarized scattered light component reflected from the flakes, thereby enhancing the effective intensity of circularly polarized light reflected from the flakes when the flakes are oriented into a light reflecting state. Electro-optic devices contain these doped flakes suspended in a host fluid can be addressed with an applied electric field, thus controlling the orientation of the flakes between a bright reflecting state and a non-reflecting dark state.

Trajkovska-Petkoska, Anka; Jacobs, Stephen D.; Marshall, Kenneth L.; Kosc, Tanya Z.

2010-05-11T23:59:59.000Z

320

Suppression of the spin pumping in Pd/Ni{sub 81}Fe{sub 19} bilayers with nano-oxide layer  

SciTech Connect (OSTI)

We demonstrate that the spin pumping effect can be effectively suppressed with a nano-oxide layer. Spin pumping effect manifests itself by an enhancement of the Gilbert damping parameter in normal metal/ferromagnetic hetero-structures, while many spintronics devices prefer smaller damping parameter. Since the spin pumping effect is directly related with the spin dependent interface conductance, we can modify the spin pumping by altering the interface conductance with the nano-oxide layer. We prepared series of Pd/Ni{sub 81}Fe{sub 19} bilayers with different pausing time between Pd and Ni{sub 81}Fe{sub 19} depositions in order to control the interface conductance. The Gilbert damping parameters are determined from the line-width measurements in the ferromagnetic resonance spectra for each pausing time sample. They are 0.0490, 0.0296, 0.0278, and 0.0251 for 0, 6, 30, and 60 s pausing time, respectively. We find that the damping parameter of Pd/Ni{sub 81}Fe{sub 19} is almost recovered to one of the Cu/Ni{sub 81}Fe{sub 19} bilayer with 60 s pausing time, while the static magnetic properties are not noticeably changed.

Kim, Duck-Ho; Kim, Hong-Hyoun; You, Chun-Yeol [Department of Physics, Inha University, Namgu Incheon 402-751 (Korea, Republic of)

2011-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.


321

Effect of doping on electronic states in B-doped polycrystalline CVD diamond films This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network [OSTI]

Effect of doping on electronic states in B-doped polycrystalline CVD diamond films This article has-doped polycrystalline CVD diamond films O S Elsherif1,4, K D Vernon-Parry1, J H Evans-Freeman2 and P W May3 1 Materials the effect of boron (B) concentration on the electronic states in polycrystalline chemical vapour deposition

Bristol, University of

322

Zirconium-doped tantalum oxide high-k gate dielectric films  

E-Print Network [OSTI]

A new high-k dielectric material, i.e., zirconium-doped tantalum oxide (Zr-doped TaOx), in the form of a sputter-deposited thin film with a thickness range of 5-100 nm, has been studied. Important applications of this new dielectric material include...

Tewg, Jun-Yen

2005-02-17T23:59:59.000Z

323

Joining of highly aluminum-doped lanthanum strontium manganese oxide with tetragonal zirconia by plastic deformation  

E-Print Network [OSTI]

Joining of highly aluminum-doped lanthanum strontium manganese oxide with tetragonal zirconia February 2008; accepted 24 March 2008 Abstract Aluminum-doped lanthanum strontium manganese oxide, La0.77Sr at the interface. © 2008 Elsevier B.V. All rights reserved. Keywords: Lanthanum strontium aluminum manganese oxide

Dutta, Prabir K.

324

Exploting iron doping in zirconia D. Sangalli, A. Lamperti, E. Cianci, R. Ciprian, M. Perego  

E-Print Network [OSTI]

As/GaAs Ohno et al., PRL 68, 2664 (1992)Ohno et al., PRL 68, 2664 (1992) Ohno et al., APL 69 363 (1996)Ohno etPredicted very high Tc for TM doped ZrO2for TM doped ZrO2 Ostanin et al., PRL 98 016011 (2007)Ostanin et al., PRL

Marini, Andrea

325

Improving thermostability of CrO{sub 2} thin films by doping with Sn  

SciTech Connect (OSTI)

Chromium dioxide (CrO{sub 2}) is an ideal material for spin electronic devices since it has almost 100% spin polarization near Fermi level. However, it is thermally unstable and easily decomposes to Cr{sub 2}O{sub 3} even at room temperature. In this study, we try to improve the thermal stability of CrO{sub 2} thin films by doping with Sn whose oxide has the same structure as CrO{sub 2}. High quality epitaxial CrO{sub 2} and Sn-doped CrO{sub 2} films were grown on single crystalline TiO{sub 2} (100) substrates by chemical vapor deposition. Sn{sup 4+} ions were believed to be doped into CrO{sub 2} lattice and take the lattice positions of Cr{sup 4+}. The magnetic measurements show that Sn-doping leads to a decrease of magnetocrystalline anisotropy. The thermal stabilities of the films were evaluated by annealing the films at different temperatures. Sn-doped films can withstand a temperature up to 510?°C, significantly higher than what undoped films can do (lower than 435?°C), which suggests that Sn-doping indeed enhances the thermal stability of CrO{sub 2} films. Our study also indicates that Sn-doping may not change the essential half metallic properties of CrO{sub 2}. Therefore, Sn-doped CrO{sub 2} is expected to be very promising for applications in spintronic devices.

Ding, Yi; Wang, Ziyu; Liu, Shuo; Shi, Jing; Yin, Di, E-mail: dyin@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Yuan, Cheng; Lu, Zhihong, E-mail: zludavid@live.com [School of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081 (China); Xiong, Rui, E-mail: xiongrui@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Wuhan 430062 (China)

2014-09-01T23:59:59.000Z

326

Excitation mechanisms in dye-doped organic light-emitting devices F. Pschenitzkaa)  

E-Print Network [OSTI]

Excitation mechanisms in dye-doped organic light-emitting devices F. Pschenitzkaa) and J. C. Sturmb In an organic light-emitting device with a polymeric matrix concurrently doped with two different dyes, the photoluminescence PL and electroluminescence EL spectra are observed to be very different, with both dyes emitting

327

Enhanced laser performance of cholesteric liquid crystals doped with oligofluorene dye  

E-Print Network [OSTI]

Enhanced laser performance of cholesteric liquid crystals doped with oligofluorene dye Ksenia); published August 19, 2008 We propose a new highly efficient organic dye, oligofluorene, which has great) doped with oligofluorene and a well- studied dye, 4-(dicyanomethylene)-Z-methyl-6-(4-dimethylaminostryl

Boyd, Robert W.

328

High Contrast and Fast Response Polarization-Independent Reflective Display Using a Dye-Doped  

E-Print Network [OSTI]

High Contrast and Fast Response Polarization- Independent Reflective Display Using a Dye-Doped Dual-host reflective display using a dye-doped dual- frequency liquid crystal (DFLC) gel. By combining dye absorption (typically $10:1) of the employed dyes. Increasing This work was supported by Toppoly Optoelectronics (Taiwan

Wu, Shin-Tson

329

Importance of dye host on absorption, propagation losses, and amplified spontaneous emission for dye-doped  

E-Print Network [OSTI]

Importance of dye host on absorption, propagation losses, and amplified spontaneous emission for dye-doped polymer thin films Hélène Goudket, Tran Hong Nhung, Buntha Ea-Kim, Gisèle Roger, and Michael Canva The absorption spectra of dye-doped polymer thin films made from a variety of five dyes and six

Paris-Sud XI, Université de

330

Stable doped hybrid sol-gel materials for solid-state dye laser  

E-Print Network [OSTI]

Stable doped hybrid sol-gel materials for solid-state dye laser Tran H. Nhung, Michael Canva have been obtained with dye-doped hybrid xerogel samples prepared several years ago and stored dye into a hybrid xerogel matrix and obtained good laser performances similar to the rest

Paris-Sud XI, Université de

331

ccsd00002689, Dependence of the superconducting transition temperature on the doping level in  

E-Print Network [OSTI]

reported for heavily boron-doped polycrystalline diamond pre- pared either as bulk [1] or thin #12;lm on the doping level in single crystalline diamond #12;lms E. Bustarret 1 , J. Ka#20;cmar#20;cik 2;3 , C Joseph Fourier, B.P.53, 38041 Grenoble Cedex 9, France (Dated: August 24, 2004) Homoepitaxial diamond

332

Studies of n-type doping and surface modification of CVD diamond for use  

E-Print Network [OSTI]

strategy in chemical vapour deposition (CVD) of polycrystalline diamond films. Lithium nitride (Li3NStudies of n-type doping and surface modification of CVD diamond for use in thermionic applications-type dopants in diamond, the work has examined the use of Li-N codoping as a possible alternative doping

Bristol, University of

333

Field emission properties of phosphorus doped microwave plasma chemical vapor deposition diamond films by ion implantation  

E-Print Network [OSTI]

2002; published 5 February 2003 Phosphorus doped polycrystalline diamond films were grown using ion the electrical char- acteristics of diamond FEAs to lower the operating voltage. Polycrystalline diamond hasField emission properties of phosphorus doped microwave plasma chemical vapor deposition diamond

Lee, Jong Duk

334

Boron Doping of Microcrystalline and Nanocrystalline Diamond Films: Where is the Boron Paul William May1  

E-Print Network [OSTI]

is that polycrystalline boron-doped CVD diamond films possess grain boundaries containing a small-volume fraction of non-diamondBoron Doping of Microcrystalline and Nanocrystalline Diamond Films: Where is the Boron Going? Paul `cauliflower'-type nanocrystalline (c-NCD) CVD diamond films vary as a function of B content. The conductivity

Bristol, University of

335

Spatially-correlated microstructure and superconductivity in polycrystalline Boron-doped diamond  

E-Print Network [OSTI]

Spatially-correlated microstructure and superconductivity in polycrystalline Boron-doped diamond F are performed below 100 mK on polycrystalline Boron-doped diamond films characterized by Transmission Electron and the superconducting proximity effect.8,9 Neverthe- less, recent studies of polycrystalline diamond films10,11 did

Paris-Sud XI, Université de

336

Raman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond  

E-Print Network [OSTI]

superconductivity at temperatures polycrystalline boron-doped CVD diamond filmsRaman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films P.W. May a,*, W.J. Ludlow a , M. Hannaway a , P.J. Heard b , J

Bristol, University of

337

Raman characterization of boron-doped multiwalled carbon nanotubes J. Maultzsch,a)  

E-Print Network [OSTI]

. We interpret this result as an indication that the high-energy mode in carbon nanotubes is defectRaman characterization of boron-doped multiwalled carbon nanotubes J. Maultzsch,a) S. Reich, and C of boron-doped multiwalled carbon nanotubes. The Raman intensities are analyzed as a function

Nabben, Reinhard

338

Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped Emmanuel Rousseau  

E-Print Network [OSTI]

Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped silicon the role of surface plasmons for nanoscale radiative heat transfer between doped silicon surfaces. We derive a new accurate and closed-form expression of the radiative near- field heat transfer. We also

Paris-Sud XI, Université de

339

Tuning carrier type and density in Bi2Se3 by Ca-doping  

E-Print Network [OSTI]

samples. Two x = 0.012 Ca-doped samples have the smallest?p-type? and lower ?n-type? Ca doping have a larger E 0 .This indicates that x = 0.012 Ca is close to the compensate

2010-01-01T23:59:59.000Z

340

Dopant location identification in Nd3+ -doped TiO2 nanoparticles  

E-Print Network [OSTI]

Dopant location identification in Nd3+ -doped TiO2 nanoparticles W. Li Department of Materials. The identification of dopant position and its local environ- ment are essential to explore the effect of doping. X and Technology, Gaithersburg, Maryland 20899, USA C. Ni Department of Materials Science and Engineering

Frenkel, Anatoly

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Electrical properties of Er-doped In0.53Ga0.47As  

E-Print Network [OSTI]

03C117-3 Burke et al. : Electrical properties of Er-doped InElectrical properties of Er-doped In 0.53 Ga 0.47 As PeterBahk and John E. Bowers Electrical and Computer Engineering

Burke, Peter G.; Lu, Hong; Rudawski, Nicholas G.; Gossard, Arthur G.; Bahk, Je-Hyeong; Bowers, John E.

2011-01-01T23:59:59.000Z

342

Irradiation of Dye-Doped Microspheres with a Strongly Focused Laser Beam  

E-Print Network [OSTI]

Irradiation of Dye-Doped Microspheres with a Strongly Focused Laser Beam Results in Alignment upon Optical Trapping Garth J. Simpson, Thorsten Wohland, and Richard N. Zare* Department of Chemistry Received December 12, 2001 ABSTRACT The irradiation of dye-doped polystyrene microspheres with an argon ion

Zare, Richard N.

343

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

344

Hydrogen adsorption on Graphene and Nitrogen Doped Graphene Monolayers: A First Principles Study  

E-Print Network [OSTI]

Hydrogen adsorption on Graphene and Nitrogen Doped Graphene Monolayers: A First Principles Study Abstract This study examines the properties of graphene and nitrogen doped graphene by way of first principles spin-polarized Density Functional Theory calculations. Why graphene is so unique comes from

Petta, Jason

345

VISIBLE AND INFRARED RARE-EARTH ACTIVATED ELECTROLUMINESCENCE FROM ERBIUM DOPED GaN  

E-Print Network [OSTI]

. At the same time novel work is being conducted using rare earth elements as sources of light emission. Results. III-V semiconductors doped with rare-earth elements have also been used10VISIBLE AND INFRARED RARE-EARTH ACTIVATED ELECTROLUMINESCENCE FROM ERBIUM DOPED GaN M. Garter*, R

Steckl, Andrew J.

346

Intersubband absorption in boron-doped multiple Ge quantum dots J. L. Liu,a)  

E-Print Network [OSTI]

Intersubband absorption in boron-doped multiple Ge quantum dots J. L. Liu,a) W. G. Wu, A. Balandin; accepted for publication 3 November 1998 The intersubband absorption in self-assembled boron-doped multiple and undoped Si barriers. The infrared absorption as a function of wavelength is measured by Fourier transform

347

Erbium-doped transparent glass ceramic optical Characterization using mass spectroscopy and molecular dynamics modeling.  

E-Print Network [OSTI]

Erbium-doped transparent glass ceramic optical fibres: Characterization using mass spectroscopy) doped silica-based optical fibres with transparent glass ceramic (TGC) core were fabricated through properties of the erbium ions embedded within the phospho-silicate DNP. These results permit to get more

Boyer, Edmond

348

Europium-Doped TiO2 Hollow Nanoshells: Two-Photon Imaging of Cell Binding  

E-Print Network [OSTI]

Europium-Doped TiO2 Hollow Nanoshells: Two-Photon Imaging of Cell Binding Sergio Sandoval,,,§ Jian Laboratory, § Moores Cancer Center, Department of Chemistry & Biochemistry, Department of Nano method to fabricate luminescent monodisperse 200 nm europium-doped hollow TiO2 nanoshell (NS) particles

Kummel, Andrew C.

349

Generation of high peak power pulse using 2 stage erbium-doped fiber amplifier  

E-Print Network [OSTI]

-doped fiber. For the second stage, two 1480nm pump lasers were used to pump erbium-doped fiber in both forward and backward propagating direction. The signal laser was modulated to produce pulses with high repetition rate high peak power. The first stage...

Lee, Kyung-Woo

2012-06-07T23:59:59.000Z

350

In situ doping control of the surface of high-temperature superconductors  

E-Print Network [OSTI]

LETTERS In situ doping control of the surface of high-temperature superconductors M. A. HOSSAIN1.1038/nphys998 Central to the understanding of high-temperature superconductivity is the evolution of the electronic structure as doping alters the density of charge carriers in the CuO2 planes. Superconductivity

Michelson, David G.

351

Electrical characterisation of defects in polycrystalline B-doped diamond films  

E-Print Network [OSTI]

applied to B-doped thin polycrystalline diamond films deposited on p+ -silicon by hot filament chemical]. Recently valuable information about defects in monocrystalline [3] and polycrystalline [7] diamond filmsElectrical characterisation of defects in polycrystalline B-doped diamond films O. S. Elsherif 1, a

Bristol, University of

352

Stability of Graphene doping with MoO_3 and I_2  

E-Print Network [OSTI]

We dope graphene by evaporation of MoO_3 or by solution-deposition of I_2 and assess the doping stability for its use as transparent electrodes. Electrical measurements show that both dopants increase the graphene sheet conductivity and find that Mo...

D’Arsié, Lorenzo; Esconjauregui, Santiago; Weatherup, Robert; Guo, Yuzheng; Bhardwaj, Sunil; Centeno, Alba; Zurutuza, Amaia; Cepek, Cinzia; Robertson, John

2014-09-08T23:59:59.000Z

353

Author's personal copy Prepration and photoluminescence properties of Ce doped lutetium silicate  

E-Print Network [OSTI]

Author's personal copy Prepration and photoluminescence properties of Ce doped lutetium silicate silicate Cerium Solegel Photoluminescence Lu2SiO5 a b s t r a c t Cerium doped lutetium silicate powders%). The synthesized lutetium silicate powders were investigated by X-ray diffraction (XRD), TG-DTA, SEM

Cao, Guozhong

354

Electrical noise characteristics of a doped silicon microcantilever heater-thermometer  

E-Print Network [OSTI]

Electrical noise characteristics of a doped silicon microcantilever heater-thermometer Elise A with resistive heater-thermometers,10­13 there is a lack of published reports on the electrical noise silicon heater- thermometer cantilevers.12 However, a key difference is that doped silicon heater-thermometers

King, William P.

355

Physical and magnetic properties of highly aluminum doped strontium ferrite nanoparticles prepared by auto-combustion route  

E-Print Network [OSTI]

Physical and magnetic properties of highly aluminum doped strontium ferrite nanoparticles prepared-Hexaferrite Al doped Sr-Ferrite High Coercivity Ferrite a b s t r a c t Highly Al3þ ion doped nanocrystalline Sr microscope show growth of needle shaped ferrites with high aspect ratio at Al3þ ion content exceeding xZ2. Al

Liu, J. Ping

356

Effect of carbazoleoxadiazole excited-state complexes on the efficiency of dye-doped light-emitting diodes  

E-Print Network [OSTI]

Effect of carbazole­oxadiazole excited-state complexes on the efficiency of dye-doped light a profound effect on the external quantum efficiency of dye-doped organic light-emitting diodes employing the matrix to the dye. Single-layer devices doped with either coumarin 47 C47 , coumarin 6 C6 , or nile red

357

Spatially tunable laser emission in dye-doped photonic liquid crystals Yuhua Huang, Ying Zhou, and Shin-Tson Wua  

E-Print Network [OSTI]

Spatially tunable laser emission in dye-doped photonic liquid crystals Yuhua Huang, Ying Zhou laser emission of the dye-doped cholesteric liquid crystal CLC cell using a one-dimensional temperature gradient is demonstrated. The photoexcitation of dye-doped CLC device using a frequency-doubled pulsed Nd

Wu, Shin-Tson

358

Light-induced rotation of dye-doped liquid crystal droplets C. Manzo, D. Paparo, and L. Marrucci*  

E-Print Network [OSTI]

Light-induced rotation of dye-doped liquid crystal droplets C. Manzo, D. Paparo, and L. Marrucci theoretically and experimentally the rotational dynamics of micrometric droplets of dye-doped and pure liquid to be strongly enhanced in light-absorbing dye-doped materials, the question arises whether a similar enhancement

Marrucci, Lorenzo

359

MetalBosonic InsulatorSuperconductor Transition in Boron-Doped Granular Diamond Gufei Zhang,1,* Monika Zeleznik,2  

E-Print Network [OSTI]

. Second, the giant RðTÞ peak is observed in heavily boron-doped polycrystalline diamond thick filmsMetal­Bosonic Insulator­Superconductor Transition in Boron-Doped Granular Diamond Gufei Zhang,1 the onset of superconductivity in heavily boron-doped diamond. This anomalous RðTÞ peak in a 3D system

Bristol, University of

360

Zero State Doped Turbo Equalizer Orhan GAZI, is with Electronics and Communication Engineering Department, Cankaya University, 06530,  

E-Print Network [OSTI]

1 Zero State Doped Turbo Equalizer Orhan GAZI, is with Electronics and Communication Engineering. In this article we propose zero state doped turbo equalizers (ZSDTEs) which can be processed in parallel and have to the sliding window method. Index Terms-- Turbo Codes, Turbo Equalizer, Zero State Doped Turbo Equalizer. I

Yýlmaz, �zgür

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light-emitting Diodes  

E-Print Network [OSTI]

Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light and Technology, Clear Water Bay, Kowloon, Hong Kong, China ABSTRACT Aluminum doped zinc oxide (AZO that MTDATA matches better with AZO than CuPc, which served as hole injection layer. Keywords: Aluminum doped

362

Luminescence and photoinduced absorption in ytterbium-doped optical fibres  

SciTech Connect (OSTI)

Photochemical reactions induced in the glass network of an ytterbium-doped fibre core by IR laser pumping and UV irradiation have been investigated by analysing absorption and luminescence spectra. We have performed comparative studies of the photoinduced absorption and luminescence spectra of fibre preforms differing in core glass composition: Al{sub 2}O{sub 3} : SiO{sub 2}, Al{sub 2}O{sub 3} : Yb{sub 2}O{sub 3} : SiO{sub 2}, and P{sub 2}O{sub 5} : Yb{sub 2}O{sub 3} : SiO{sub 2}. The UV absorption spectra of unirradiated preform core samples show strong bands peaking at 5.1 and 6.5 eV, whose excitation plays a key role in photoinduced colour centre generation in the glass network. 'Direct' UV excitation of the 5.1- and 6.5-eV absorption bands at 244 and 193 nm leads to the reduction of some of the Yb{sup 3+} ions to Yb{sup 2+}. The photodarkening of ytterbium-doped fibres by IR pumping is shown to result from oxygen hole centre generation. A phenomenological model is proposed for the IR-pumping-induced photodarkening of ytterbium-doped fibres. The model predicts that colour centre generation in the core glass network and the associated absorption in the visible range result from a cooperative effect involving simultaneous excitation of a cluster composed of several closely spaced Yb{sup 3+} ions.

Rybaltovsky, A A; Aleshkina, S S; Likhachev, M E; Bubnov, M M; Umnikov, A A; Yashkov, M V; Gur'yanov, Aleksei N; Dianov, Evgenii M

2011-12-31T23:59:59.000Z

363

Spin-dependent electron transport in zinc- and manganese-doped adenine molecules  

SciTech Connect (OSTI)

The spin-dependent electron transport properties of zinc- and manganese-doped adenine molecules connected to zigzag graphene leads are studied in the zero bias regime using the non-equilibrium Green's function method. The conductance of the adenine molecule increased and became spin-dependent when a zinc or manganese atom was doped into the molecules. The effects of a transverse electric field on the spin-polarization of the transmitted electrons were investigated and the spin-polarization was controlled by changing the transverse electric field. Under the presence of a transverse electric field, both the zinc- and manganese-doped adenine molecules acted as spin-filters. The maximum spin-polarization of the manganese-doped adenine molecule was greater than the molecule doped with zinc.

Simchi, Hamidreza, E-mail: simchi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of); Semiconductor Technology Center, Tehran 16844 (Iran, Islamic Republic of); Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir; Mazidabadi, Hossein [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of)

2014-01-28T23:59:59.000Z

364

Atmospheric Oxygen Binding and Hole Doping in Deformed Graphene on a SiO2 Substrate  

E-Print Network [OSTI]

Using micro-Raman spectroscopy and scanning tunneling microscopy, we study the relationship between structural distortion and electrical hole doping of graphene on a silicon dioxide substrate. The observed upshift of the Raman G band represents charge doping and not compressive strain. Two independent factors control the doping: (1) the degree of graphene coupling to the substrate, and (2) exposure to oxygen and moisture. Thermal annealing induces a pronounced structural distortion due to close coupling to SiO2 and activates the ability of diatomic oxygen to accept charge from graphene. Gas flow experiments show that dry oxygen reversibly dopes graphene; doping becomes stronger and more irreversible in the presence of moisture and over long periods of time. We propose that oxygen molecular anions are stabilized by water solvation and electrostatic binding to the silicon dioxide surface.

Sunmin Ryu; Li Liu; Stephane Berciaud; Young-Jun Yu; Haitao Liu; Philip Kim; George W. Flynn; Louis E. Brus

2010-11-13T23:59:59.000Z

365

Fabrication of solar cells with counter doping prevention  

DOE Patents [OSTI]

A solar cell fabrication process includes printing of dopant sources over a polysilicon layer over backside of a solar cell substrate. The dopant sources are cured to diffuse dopants from the dopant sources into the polysilicon layer to form diffusion regions, and to crosslink the dopant sources to make them resistant to a subsequently performed texturing process. To prevent counter doping, dopants from one of the dopant sources are prevented from outgassing and diffusing into the other dopant source. For example, phosphorus from an N-type dopant source is prevented from diffusing to a P-type dopant source comprising boron.

Dennis, Timothy D; Li, Bo; Cousins, Peter John

2013-02-19T23:59:59.000Z

366

Bi-Se doped with Cu, p-type semiconductor  

DOE Patents [OSTI]

A Bi--Se doped with Cu, p-type semiconductor, preferably used as an absorber material in a photovoltaic device. Preferably the semiconductor has at least 20 molar percent Cu. In a preferred embodiment, the semiconductor comprises at least 28 molar percent of Cu. In one embodiment, the semiconductor comprises a molar percentage of Cu and Bi whereby the molar percentage of Cu divided by the molar percentage of Bi is greater than 1.2. In a preferred embodiment, the semiconductor is manufactured as a thin film having a thickness less than 600 nm.

Bhattacharya, Raghu Nath; Phok, Sovannary; Parilla, Philip Anthony

2013-08-20T23:59:59.000Z

367

Unusual dielectric response in cobalt doped reduced graphene oxide  

SciTech Connect (OSTI)

Intensive research on cobalt doped reduced graphene oxide (Co-RGO) to investigate the modification in graphene magnetism and spin polarization due to presence of transition metal atom has been carried out, however, its dielectric spectroscopy, particularly, how capacitance changes with impurity levels in graphene is relatively unexplored. In the present work, dielectric spectroscopy along with magneto-dielectric effect are investigated in Co-RGO. Contrary to other materials, here permittivity increases abruptly with frequency in the low frequency region and continues to increase till 10{sup 7}?Hz. This unusual behavior is explained on the basis of trap induced capacitance created due to impurity levels.

Akhtar, Abu Jahid; Gupta, Abhisek; Kumar Shaw, Bikash; Saha, Shyamal K., E-mail: cnssks@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

2013-12-09T23:59:59.000Z

368

Nitrogen-doped Graphene and Its Electrochemical Applications  

SciTech Connect (OSTI)

Nitrogen-doped graphene (N-graphene) is obtained by exposing graphene to nitrogen plasma. N-graphene exhibits much higher electrocatalytic activity toward oxygen reduction and H2O2 reduction than graphene, and much higher durability and selectivity than the widely-used expensive Pt. The excellent electrochemical performance of N-graphene is attributed to nitrogen functional groups and the specific properties of graphene. This indicates that N-graphene is promising for applications in electrochemical energy devices (fuel cells, metal-air batteries) and biosensors.

Shao, Yuyan; Zhang, Sheng; Engelhard, Mark H.; Li, Guosheng; Shao, Guocheng; Wang, Yong; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

2010-06-04T23:59:59.000Z

369

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 60–100 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

370

Photoresponse of Tb{sup 3+} doped phosphosilicate thin films  

SciTech Connect (OSTI)

Phosphosilicate ceramic was doped with Tb{sup 3+} using sol-gel technique to prepare thin films. The films were prepared by spin coating the phosphosilicate sols on SiO{sub x}/indium-tin-oxide/glass substrates. The photocurrent of the films at 355 nm laser excitation was observed. The photoresponse as a function of applied field and laser energy was linear and showed no sign of saturation. The films exhibited very stable photoresponse under a very high number of laser shots.

Lee, B.L.; Cao, Z. [Clemson Univ., SC (United States). Gilbert C. Robinson Dept. of Ceramic and Materials Engineering] [Clemson Univ., SC (United States). Gilbert C. Robinson Dept. of Ceramic and Materials Engineering; Sisk, W.N.; Hudak, J. [Univ. of North Carolina, Charlotte, NC (United States)] [Univ. of North Carolina, Charlotte, NC (United States); Samuels, W.D.; Exarhos, G.J. [Pacific Northwest National Lab., Richland, WA (United States). Materials and Chemical Science] [Pacific Northwest National Lab., Richland, WA (United States). Materials and Chemical Science

1997-09-01T23:59:59.000Z

371

Nitrogen-doped Graphene and Its Electrochemical Applications. | EMSL  

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

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372

Crystallization and doping of amorphous silicon on low temperature plastic  

DOE Patents [OSTI]

A method or process of crystallizing and doping amorphous silicon (a-Si) on a low-temperature plastic substrate using a short pulsed high energy source in a selected environment, without heat propagation and build-up in the substrate. The pulsed energy processing of the a-Si in a selected environment, such as BF3 and PF5, will form a doped micro-crystalline or poly-crystalline silicon (pc-Si) region or junction point with improved mobilities, lifetimes and drift and diffusion lengths and with reduced resistivity. The advantage of this method or process is that it provides for high energy materials processing on low cost, low temperature, transparent plastic substrates. Using pulsed laser processing a high (>900.degree. C.), localized processing temperature can be achieved in thin films, with little accompanying temperature rise in the substrate, since substrate temperatures do not exceed 180.degree. C. for more than a few microseconds. This method enables use of plastics incapable of withstanding sustained processing temperatures (higher than 180.degree. C.) but which are much lower cost, have high tolerance to ultraviolet light, have high strength and good transparency, compared to higher temperature plastics such as polyimide.

Kaschmitter, James L. (Pleasanton, CA); Truher, Joel B. (Palo Alto, CA); Weiner, Kurt H. (Campbell, CA); Sigmon, Thomas W. (Beaverton, OR)

1994-01-01T23:59:59.000Z

373

Chloride, bromide and iodide scintillators with europium doping  

DOE Patents [OSTI]

A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has been studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.

Zhuravleva, Mariya; Yang, Kan

2014-08-26T23:59:59.000Z

374

Crystallization and doping of amorphous silicon on low temperature plastic  

DOE Patents [OSTI]

A method or process of crystallizing and doping amorphous silicon (a-Si) on a low-temperature plastic substrate using a short pulsed high energy source in a selected environment, without heat propagation and build-up in the substrate is disclosed. The pulsed energy processing of the a-Si in a selected environment, such as BF3 and PF5, will form a doped micro-crystalline or poly-crystalline silicon (pc-Si) region or junction point with improved mobilities, lifetimes and drift and diffusion lengths and with reduced resistivity. The advantage of this method or process is that it provides for high energy materials processing on low cost, low temperature, transparent plastic substrates. Using pulsed laser processing a high (>900 C), localized processing temperature can be achieved in thin films, with little accompanying temperature rise in the substrate, since substrate temperatures do not exceed 180 C for more than a few microseconds. This method enables use of plastics incapable of withstanding sustained processing temperatures (higher than 180 C) but which are much lower cost, have high tolerance to ultraviolet light, have high strength and good transparency, compared to higher temperature plastics such as polyimide. 5 figs.

Kaschmitter, J.L.; Truher, J.B.; Weiner, K.H.; Sigmon, T.W.

1994-09-13T23:59:59.000Z

375

Chromatic instabilities in cesium-doped tungsten bronze nanoparticles  

SciTech Connect (OSTI)

Nanoparticles of alkali-doped tungsten bronzes are an excellent near-infrared shielding material, but exhibit slight chromatic instabilities typically upon applications of strong ultra-violet light or heating in humid environment, which acts detrimentally to long-life commercial applications. Origin of the chromatic instabilities in cesium-doped tungsten bronze has been investigated, and it has been found that the coloration and bleaching processes comprised electronic exchanges which accelerate or depress the polaron excitation and the localized surface plasmon resonance. Coloration on UV illumination is evidenced by electron diffraction as due to the formation of H{sub x}WO{sub 3}, which is considered to take place in the surface Cs-deficient WO{sub 3} region via the double charge injection mechanism. On the other hand, bleaching on heating in air and in humid environment is shown to accompany the extraction of Cs and electrons from Cs{sub 0.33}WO{sub 3} by X-ray photoelectron spectroscopy and X-ray diffraction analysis and is concluded to be an oxidation of Cs{sub 0.33}WO{sub 3} on the particle surface.

Adachi, Kenji, E-mail: kenji-adachi@ni.smm.co.jp; Ota, Yosuke; Tanaka, Hiroyuki; Okada, Mika; Oshimura, Nobumitsu; Tofuku, Atsushi [Ichikawa Research Laboratories, Sumitomo Metal Mining Co., Ltd., Ichikawa 272-8588 (Japan)

2013-11-21T23:59:59.000Z

376

Carbon doping of III-V compound semiconductors  

SciTech Connect (OSTI)

Focus of the study is C acceptor doping of GaAs, since C diffusion coefficient is at least one order of magnitude lower than that of other common p-type dopants in GaAs. C ion implantation results in a concentration of free holes in the valence band < 10% of that of the implanted C atoms for doses > 10{sup 14}/cm{sup 2}. Rutherford backscattering, electrical measurements, Raman spectroscopy, and Fourier transform infrared spectroscopy were amonth the techniques used. Ga co-implantation increased the C activation in two steps: first, the additional radiation damage creates vacant As sites that the implanted C can occupy, and second, it maintains the stoichiometry of the implanted layer, reducing the number of compensating native defects. In InP, the behavior of C was different from that in GaAs. C acts as n-type dopant in the In site; however, its incorporation by implantation was difficult to control; experiments using P co-implants were inconsistent. The lattice position of inactive C in GaAs in implanted and epitaxial layers is discussed; evidence for formation of C precipitates in GaAs and InP was found. Correlation of the results with literature on C doping in III-V semiconductors led to a phenomenological description of C in III-V compounds (particularly GaAs): The behavior of C is controlled by the chemical nature of C and the instrinsic Fermi level stabilization energy of the material.

Moll, A.J.

1994-09-01T23:59:59.000Z

377

Near-infrared free carrier absorption in heavily doped silicon  

SciTech Connect (OSTI)

Free carrier absorption in heavily doped silicon can have a significant impact on devices operating in the infrared. In the near infrared, the free carrier absorption process can compete with band to band absorption processes, thereby reducing the number of available photons to optoelectronic devices such as solar cells. In this work, we fabricate 18 heavily doped regions by phosphorus and boron diffusion into planar polished silicon wafers; the simple sample structure facilitates accurate and precise measurement of the free carrier absorptance. We measure and model reflectance and transmittance dispersion to arrive at a parameterisation for the free carrier absorption coefficient that applies in the wavelength range between 1000 and 1500?nm, and the range of dopant densities between ?10{sup 18} and 3?×?10{sup 20}?cm{sup ?3}. Our measurements indicate that previously published parameterisations underestimate the free carrier absorptance in phosphorus diffusions. On the other hand, published parameterisations are generally consistent with our measurements and model for boron diffusions. Our new model is the first to be assigned uncertainty and is well-suited to routine device analysis.

Baker-Finch, Simeon C., E-mail: simeon.bakerfinch@gmail.com [School of Engineering, Australian National University, Canberra, ACT 0200 (Australia); PV Lighthouse, Coledale, NSW 2515 (Australia); McIntosh, Keith R. [PV Lighthouse, Coledale, NSW 2515 (Australia); Yan, Di; Fong, Kean Chern; Kho, Teng C. [School of Engineering, Australian National University, Canberra, ACT 0200 (Australia)

2014-08-14T23:59:59.000Z

378

Time-domain detection of current controlled magnetization damping in Pt/Ni{sub 81}Fe{sub 19} bilayer and determination of Pt spin Hall angle  

SciTech Connect (OSTI)

The effect of spin torque from the spin Hall effect in Pt/Ni{sub 81}Fe{sub 19} rectangular bilayer film was investigated using time-resolved magneto-optical Kerr microscopy. Current flow through the stack resulted in a linear variation of effective damping up to ±7%, attributed to spin current injection from the Pt into the Ni{sub 81}Fe{sub 19}. The spin Hall angle of Pt was estimated as 0.11?±?0.03. The modulation of the damping depended on the angle between the current and the bias magnetic field. These results demonstrate the importance of optical detection of precessional magnetization dynamics for studying spin transfer torque due to spin Hall effect.

Ganguly, A.; Haldar, A.; Sinha, J.; Barman, A., E-mail: abarman@bose.res.in, E-mail: del.atkinson@durham.ac.uk [Thematic Unit of Excellence on Nanodevice Technology, Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata 700098 (India); Rowan-Robinson, R. M.; Jaiswal, S.; Hindmarch, A. T.; Atkinson, D. A., E-mail: abarman@bose.res.in, E-mail: del.atkinson@durham.ac.uk [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

2014-09-15T23:59:59.000Z

379

High thermal stability and low Gilbert damping constant of CoFeB/MgO bilayer with perpendicular magnetic anisotropy by Al capping and rapid thermal annealing  

SciTech Connect (OSTI)

We demonstrate that the magnetic anisotropy of the CoFeB/MgO bilayer can be manipulated by adding an aluminum capping layer. After rapid thermal annealing, we can achieve large perpendicular magnetic anisotropy of CoFeB with a high thermal stability factor (??=?72) while the Gilbert damping constant can be reduced down to only 0.011 simultaneously. The boron and residual oxygen in the bulk CoFeB layer are properly absorbed by the Al capping layer during annealing, leading to the enhanced exchange stiffness and reduced damping. The interfacial Fe-O bonding can be optimized by tuning annealing temperature and thickness of Al, resulting in enhanced perpendicular anisotropy.

Wang, Ding-Shuo; Lai, Shu-Yu; Lin, Tzu-Ying; Wang, Liang-Wei; Liao, Jung-Wei; Lai, Chih-Huang, E-mail: chlai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Chien, Cheng-Wei; Wang, Yung-Hung [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan (China); Ellsworth, David; Lu, Lei; Wu, Mingzhong [Department of Physics, Colorado State University, Fort Collins, Colorado 80523 (United States)

2014-04-07T23:59:59.000Z

380

Broad spectral response photodetector based on individual tin-doped CdS nanowire  

SciTech Connect (OSTI)

High purity and tin-doped 1D CdS micro/nano-structures were synthesized by a convenient thermal evaporation method. SEM, EDS, XRD and TEM were used to examine the morphology, composition, phase structure and crystallinity of as-prepared samples. Raman spectrum was used to confirm tin doped into CdS effectively. The effect of impurity on the photoresponse properties of photodetectors made from these as-prepared pure and tin-doped CdS micro/nano-structures under excitation of light with different wavelength was investigated. Various photoconductive parameters such as responsivity, external quantum efficiency, response time and stability were analyzed to evaluate the advantage of doped nanowires and the feasibility for photodetector application. Comparison with pure CdS nanobelt, the tin-doped CdS nanowires response to broader spectral range while keep the excellect photoconductive parameters. Both trapped state induced by tin impurity and optical whispering gallery mode microcavity effect in the doped CdS nanowires contribute to the broader spectral response. The micro-photoluminescence was used to confirm the whispering gallery mode effect and deep trapped state in the doped CdS nanowires.

Zhou, Weichang, E-mail: wchangzhou@gmail.com, E-mail: dstang@hunnu.edu.cn; Peng, Yuehua; Yin, Yanling; Zhou, Yong; Zhang, Yong; Tang, Dongsheng, E-mail: wchangzhou@gmail.com, E-mail: dstang@hunnu.edu.cn [Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of Education, College of Physics and Information Science, Hunan Normal University, Changsha 410081 (China)

2014-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.
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to obtain the most current and comprehensive results.


381

Structural, optical and ethanol sensing properties of Cu-doped SnO{sub 2} nanowires  

SciTech Connect (OSTI)

In present work, one-dimensional nanostructure of Cu-doped Tin oxide (SnO{sub 2}) was synthesized by using thermal evaporation method in a tubular furnace under Nitrogen (N{sub 2}) ambience. The growth was carried out at atmospheric pressure. SEM and TEM images reveal the growth of wire-like nanostructures of Cu-doped SnO{sub 2} on Si substrate. The XRD analysis confirms that the synthesized SnO{sub 2} nanowires have tetragonal rutile structure with polycrystalline nature and X-ray diffraction pattern also showed that Cu gets incorporated into the SnO{sub 2} lattice. EDX spectra confirm the doping of Cu into SnO{sub 2} nanowires and atomic fraction of Cu in nanowires is ? 0.5 at%. The Vapor Liquid Solid (VLS) growth mechanism for Cu-doped SnO{sub 2} nanowires was also confirmed by EDX spectra. The optical properties of as grown Cu-doped SnO{sub 2} nanowires were studied by using UV-vis spectra which concludes the band gap of about 3.7 eV. As synthesized single Cu-doped SnO{sub 2} nanowire based gas sensor exhibit relatively good performance to ethanol gas. This sensing behaviour offers a suitable application of the Cu-doped SnO{sub 2} nanowire sensor for detection of ethanol gas.

Johari, Anima, E-mail: animajohari@gmail.com; Sharma, Manish [Center for Applied Research in Electronics (CARE), IIT Delhi, Hauz khas, New Delhi-110016 (India); Johari, Anoopshi [THDC Institute of Hydropower Institute of Engineering and Technology, Tehri-249124 (India); Bhatnagar, M. C. [Physics Department, IIT Delhi, Hauz khas, New Delhi-110016 (India)

2014-04-24T23:59:59.000Z

382

Ge doped GaN with controllable high carrier concentration for plasmonic applications  

SciTech Connect (OSTI)

Controllable Ge doping in GaN is demonstrated for carrier concentrations of up to 2.4?×?10{sup 20} cm{sup ?3}. Low temperature luminescence spectra from the highly doped samples reveal band gap renormalization and band filling (Burstein-Moss shift) in addition to a sharp transition. Infrared ellipsometry spectra demonstrate the existence of electron plasma with an energy around 3500?cm{sup ?1} and a surface plasma with an energy around 2000?cm{sup ?1}. These findings open possibilities for the application of highly doped GaN for plasmonic devices.

Kirste, Ronny; Hoffmann, Marc P.; Sachet, Edward; Bobea, Milena; Bryan, Zachary; Bryan, Isaac; Maria, Jon-Paul; Collazo, Ramón; Sitar, Zlatko [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States)] [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States); Nenstiel, Christian; Hoffmann, Axel [Institut f?r Festkörperphsyik, TU-Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany)] [Institut f?r Festkörperphsyik, TU-Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany)

2013-12-09T23:59:59.000Z

383

Dynamics of iron-acceptor-pair formation in co-doped silicon  

SciTech Connect (OSTI)

The pairing dynamics of interstitial iron and dopants in silicon co-doped with phosphorous and several acceptor types are presented. The classical picture of iron-acceptor pairing dynamics is expanded to include the thermalization of iron between different dopants. The thermalization is quantitatively described using Boltzmann statistics and different iron-acceptor binding energies. The proper understanding of the pairing dynamics of iron in co-doped silicon will provide additional information on the electronic properties of iron-acceptor pairs and may become an analytical method to quantify and differentiate acceptors in co-doped silicon.

Bartel, T.; Gibaja, F.; Graf, O.; Gross, D.; Kaes, M.; Heuer, M.; Kirscht, F. [Calisolar GmbH, Magnusstrasse 11, 12489 Berlin (Germany)] [Calisolar GmbH, Magnusstrasse 11, 12489 Berlin (Germany); Möller, C. [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany) [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany); TU Ilmenau, Institut für Physik, Weimarer Str. 32, 98693 Ilmenau (Germany); Lauer, K. [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany)] [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany)

2013-11-11T23:59:59.000Z

384

Thermophotovoltaic energy conversion system having a heavily doped n-type region  

DOE Patents [OSTI]

A thermophotovoltaic (TPV) energy conversion semiconductor device is provided which incorporates a heavily doped n-type region and which, as a consequence, has improved TPV conversion efficiency. The thermophotovoltaic energy conversion device includes an emitter layer having first and second opposed sides and a base layer in contact with the first side of the emitter layer. A highly doped n-type cap layer is formed on the second side of the emitter layer or, in another embodiment, a heavily doped n-type emitter layer takes the place of the cap layer.

DePoy, David M. (Clifton Park, NY); Charache, Greg W. (Clifton Park, NY); Baldasaro, Paul F. (Clifton Park, NY)

2000-01-01T23:59:59.000Z

385

Structural and magnetic properties of chromium doped zinc ferrite  

SciTech Connect (OSTI)

Zinc chromium ferrites with chemical formula ZnCr{sub x}Fe{sub 2?x}O{sub 4} (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by Sol - Gel technique. The structural as well as magnetic properties of the synthesized samples have been studied and reported here. The structural characterizations of the samples were analyzed by using X – Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The single phase spinel cubic structure of all the prepared samples was tested by XRD and FTIR. The particle size was observed to decrease from 18.636 nm to 6.125 nm by chromium doping and induced a tensile strain in all the zinc chromium mixed ferrites. The magnetic properties of few samples (x = 0.0, 0.4, 1.0) were investigated using Vibrating Sample Magnetometer (VSM)

Sebastian, Rintu Mary; Thankachan, Smitha; Xavier, Sheena; Mohammed, E. M., E-mail: emmohammed2005@gmail.com [Research Department of Physics, Maharaja's College, Ernakulam, Kerala (India); Joseph, Shaji [Department of Physic, St. Albert's College, Ernakulam, Kerala (India)

2014-01-28T23:59:59.000Z

386

Welding and Weldability of Thorium-Doped Iridium Alloys  

SciTech Connect (OSTI)

Ir-0.3%W alloys doped with thorium are currently used as post-impact containment material for radioactive fuel in thermoelectric generators that provide stable electrical power for a variety of outer planetary space exploration missions. Welding and weldability of a series of alloys was investigated using arc and laser welding processes. Some of these alloys are prone to severe hot-cracking during welding. Weldability of these alloys was characterized using Sigmajig weldability test. Hot-cracking is influenced to a great extent by the fusion zone microstructure and composition. Thorium content and welding atmosphere were found to be very critical. The weld cracking behavior in these alloys can be controlled by modifying the fusion zone microstructure. Fusion zone microstructure was found to be controlled by welding process, process parameters, and the weld pool shape.

David, S.A.; Ohriner, E.K.; King, J.F.

2000-03-12T23:59:59.000Z

387

Gain properties of dye-doped polymer thin films  

E-Print Network [OSTI]

The demonstration of an electrically pumped organic laser remains a major issue of organic optoelectronics for several decades. Nowadays, hybrid pumping seems a promising compromise where the organic material is optically pumped by an electrically pumped inorganic device on chip. This technical solution requires therefore an optimization of the organic gain medium under optical pumping. Here, we report a detailed study of gain features of dye-doped polymer thin films, in particular we introduce the gain efficiency $K$, in order to facilitate comparison between material and experimental conditions. First, we measure the bulk gain by the means of a pump-probe setup, and then present in details several factors which modify the actual gain of the layer, namely the confinement factor, the pump polarization, the molecular anisotropy, and the re-absorption. The usual model to evaluate the gain leads to an overestimation by more than one order of magnitude, which stresses the importance to design the devices accordin...

Gozhyk, I; Rabbani, H; Djellali, N; Forget, S; Chenais, S; Ulysse, C; Brosseau, A; Gauvin, S; Zyss, J; Lebental, M

2014-01-01T23:59:59.000Z

388

Pulsed energy synthesis and doping of silicon carbide  

DOE Patents [OSTI]

A method for producing beta silicon carbide thin films by co-depositing thin films of amorphous silicon and carbon onto a substrate is disclosed, whereafter the films are irradiated by exposure to a pulsed energy source (e.g. excimer laser) to cause formation of the beta-SiC compound. Doped beta-SiC may be produced by introducing dopant gases during irradiation. Single layers up to a thickness of 0.5-1 micron have been produced, with thicker layers being produced by multiple processing steps. Since the electron transport properties of beta silicon carbide over a wide temperature range of 27--730 C is better than these properties of alpha silicon carbide, they have wide application, such as in high temperature semiconductors, including HETEROJUNCTION-junction bipolar transistors and power devices, as well as in high bandgap solar arrays, ultra-hard coatings, light emitting diodes, sensors, etc.

Truher, J.B.; Kaschmitter, J.L.; Thompson, J.B.; Sigmon, T.W.

1995-06-20T23:59:59.000Z

389

Pulsed energy synthesis and doping of silicon carbide  

DOE Patents [OSTI]

A method for producing beta silicon carbide thin films by co-depositing thin films of amorphous silicon and carbon onto a substrate, whereafter the films are irradiated by exposure to a pulsed energy source (e.g. excimer laser) to cause formation of the beta-SiC compound. Doped beta-SiC may be produced by introducing dopant gases during irradiation. Single layers up to a thickness of 0.5-1 micron have been produced, with thicker layers being produced by multiple processing steps. Since the electron transport properties of beta silicon carbide over a wide temperature range of 27.degree.-730.degree. C. is better than these properties of alpha silicon carbide, they have wide application, such as in high temperature semiconductors, including hetero-junction bipolar transistors and power devices, as well as in high bandgap solar arrays, ultra-hard coatings, light emitting diodes, sensors, etc.

Truher, Joel B. (San Rafael, CA); Kaschmitter, James L. (Pleasanton, CA); Thompson, Jesse B. (Brentwood, CA); Sigmon, Thomas W. (Beaverton, OR)

1995-01-01T23:59:59.000Z

390

Enhanced superconducting pairing interaction in indium-doped tin telluride  

SciTech Connect (OSTI)

The ferroelectric degenerate semiconductor Sn{sub 1-{delta}}Te exhibits superconductivity with critical temperatures, T{sub c}, of up to 0.3 K for hole densities of order 10{sup 21} cm{sup -3}. When doped on the tin site with greater than x{sub c} = 1.7(3)% indium atoms, however, superconductivity is observed up to 2 K, though the carrier density does not change significantly. We present specific heat data showing that a stronger pairing interaction is present for x > x{sub c} than for x < x{sub c}. By examining the effect of In dopant atoms on both T{sub c} and the temperature of the ferroelectric structural phase transition, T{sub SPT}, we show that phonon modes related to this transition are not responsible for this T{sub c} enhancement, and discuss a plausible candidate based on the unique properties of the indium impurities.

Erickson, A.S.

2010-05-03T23:59:59.000Z

391

Enhanced superconducting pairing interaction in indium-doped tin telluride  

SciTech Connect (OSTI)

The ferroelectric degenerate semiconductor Sn{sub 1-{delta}}Te exhibits superconductivity with critical temperatures, T{sub c}, of up to 0.3 K for hole densities of order 10{sup 21} cm{sup -3}. When doped on the tin site with greater than x{sub c} = 1.7(3)% indium atoms, however, superconductivity is observed up to 2 K, though the carrier density does not change significantly. We present specific heat data showing that a stronger pairing interaction is present for x > x{sub c} than for x < x{sub c}. By examining the effect of In dopant atoms on both T{sub c} and the temperature of the ferroelectric structural phase transition, T{sub SPT}, we show that phonon modes related to this transition are not responsible for this T{sub c} enhancement, and discuss a plausible candidate based on the unique properties of the indium impurities.

Erickson, A.S.; Chu, J.-H.; /Stanford U., Appl. Phys. Dept. /Stanford U., Geballe Lab.; Toney, M.F.; Geballe, T.H.; Fisher, I.R.; /SLAC, SSRL /Stanford U., Appl. Phys. Dept. /Stanford U., Geballe Lab.

2010-02-15T23:59:59.000Z

392

Lattice vibrations of pure and doped GaSe  

SciTech Connect (OSTI)

The Bridgman method is used to grow especially undoped and doped single crystals of GaSe. Composition and impurity content of the grown crystals were determined using X-ray fluorescence (XRF) method. X-ray diffraction, Raman scattering, photoluminescence (PL), and IR transmission measurements were performed at room temperature. The long wavelength lattice vibrations of four modifications of GaSe were described in the framework of modified one-layer linear-chain model which also takes into consideration the interaction of the selenium (Se) atom with the second nearest neighbor gallium (Ga) atom in the same layer. The existence of an eight-layer modification of GaSe is suggested and the vibrational frequencies of this modification are explained in the framework of a lattice dynamical model considered in the present work. Frequencies and the type of vibrations (gap, local, or resonance) for the impurity atoms were calculated and compared with the experimental results.

Allakhverdiev, K. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey) and Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan)]. E-mail: kerim.allahverdi@mam.gov.tr; Baykara, T. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey); Ellialtioglu, S. [Department of Physics, Middle East Technical University, Ankara 06531 (Turkey); Hashimzade, F. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan); Huseinova, D. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan); Kawamura, K. [Institute of Materials Science, University of Tsukuba 305-8573 (Japan); Kaya, A.A. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey); Kulibekov, A.M. [Department of Physics, Mugla University, Mugla 48000 (Turkey); Onari, S. [Institute of Materials Science, University of Tsukuba 305-8573 (Japan)

2006-04-13T23:59:59.000Z

393

Bismuth-doped Mg - Al silicate glasses and fibres  

SciTech Connect (OSTI)

This paper compares the optical properties of bulk bismuth-doped Mg - Al silicate glasses prepared in an iridium crucible to those of optical fibres prepared by the powder-in-tube method and having a core identical in composition to the glasses. The bulk glasses and fibres are shown to be similar in luminescence properties. The optical loss in the fibres in their IR luminescence band is about one order of magnitude lower than that in the crucible-melted glasses. The level of losses in the fibres and their luminescence properties suggest that such fibres can be made to lase near 1.15 {mu}m. (optical fibres, lasers and amplifiers. properties and applications)

Bufetov, Igor' A; Vel'miskin, V V; Galagan, B I; Denker, B I; Sverchkov, S E; Semjonov, S L; Firstov, Sergei V; Shulman, I L; Dianov, Evgenii M

2012-09-30T23:59:59.000Z

394

Scintillation properties of some Ce[sup 3+] and Pr[sup 3+] doped inorganic crystals  

SciTech Connect (OSTI)

The scintillations properties of Ce[sup 3+] and Pr[sup 3+] doped complex fluoride crystals of composition CsGd[sub 2]F[sub 7] and K[sub 2]YF[sub 5] and of Pr[sup 3+] doped Y[sub 3]Al[sub 5]O[sub 12] single crystals were studied by means of x-ray and gamma ray excitation. The Ce[sub 3+] and Pr[sub 3+] doped fluoride crystals show 5d-4f luminescences at wavelengths near 340 nm and 240 nm, respectively. 5d-4f luminescence of Pr[sup 3+] doped Y[sub 3]Al[sub 5]O[sub 12] is observed between 300 and 400 nm. The authors present the absolute light yield in photons/MeV together with results from scintillation decay time experiments.

Dorenbos, P.; Visser, R.; Eijk, C.W.E. van (Delft Univ. of Technology (Netherlands). Dept. of Applied Physics); Khaidukov, N.M. (N.S. Kurnakov Inst. of General and Inorganic Chemistry, Moscow (Russian Federation)); Korzhik, M.V. (Inst. of Nuclear Problems, Minsk (Russian Federation))

1993-08-01T23:59:59.000Z

395

Structural properties of fluorozirconate-based glass ceramics doped with multivalent europium  

SciTech Connect (OSTI)

The structure/property relationships of fluorochlorozirconate glass ceramics as a function of divalent and trivalent europium (Eu) co-doping and thermal processing have been investigated; the influence of doping ratio on the formation of barium chloride (BaCl{sub 2}) nanocrystals therein was elucidated. X-ray absorption near-edge structure spectroscopy shows that the post-thermal annealing changes the Eu valence of the as-poured glass slightly, but during the melting process Eu{sup 3+} is more strongly reduced to Eu{sup 2+}, in particular, when doped as a chloride instead of fluoride compound. The Eu{sup 2+}-to-Eu{sup 3+} doping ratio also plays a significant role in chemical equilibrium in the melt. X-ray diffraction measurements indicate that a higher Eu{sup 2+} fraction leads to a BaCl{sub 2} phase transition from hexagonal to orthorhombic structure at a lower temperature.

Passlick, C. [Centre for Innovation Competence SiLi-nano registered , Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale) (Germany); Mueller, O.; Luetzenkirchen-Hecht, D.; Frahm, R. [Bergische Universitaet Wuppertal, Gaussstrasse 20, 42097 Wuppertal (Germany); Johnson, J. A. [Department of Biomedical Engineering, University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States); Schweizer, S. [Centre for Innovation Competence SiLi-nano registered , Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale) (Germany); Fraunhofer Center for Silicon Photovoltaics CSP, Walter-Huelse-Str. 1, 06120 Halle (Saale) (Germany)

2011-12-01T23:59:59.000Z

396

Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films  

E-Print Network [OSTI]

Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films Principal-property relationships of well- defined epitaxial tungsten trioxide (WO3) films with and without dopants, and thereby

397

Preparation and sintering of silica-doped zirconia by colloidal processing  

SciTech Connect (OSTI)

Silica-doped (SiO{sub 2} = 0--1.0 mass%) zirconia (3 mol% Y{sub 2}O{sub 3}-doped tetragonal ZrO{sub 2}) compacts are prepared from hetero-coagulated and well-dispersed suspensions by colloidal processing. The suspensions are consolidated by a pressure filtration technique. The green density of the compacts consolidated from the well-dispersed suspensions is higher than that from the hetero-coagulated suspensions. The lower density of the latter compacts is improved by a subsequent cold isostatic pressing (CIP) at 400 MPa. The sinterability of the compacts at 1,200 C is greatly affected by the amount of doped silica. The densification and grain growth are hindered by silica doping above 0.3 wt% at 1,200 C. All the compacts are densificated to a relative density of above 99% by sintering at 1,300 C for 2 h.

Uchikoshi, T.; Sakka, Y.; Ozawa, K.; Hiraga, K. [National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)

1997-09-01T23:59:59.000Z

398

JOURNAL OF MATERIALS SCIENCE 36 (2001) 77 86 Synthesis of yttria-doped strontium-zirconium  

E-Print Network [OSTI]

JOURNAL OF MATERIALS SCIENCE 36 (2001) 77­ 86 Synthesis of yttria-doped strontium-zirconium oxide densification, than co-precipitated powders. C 2001 Kluwer Academic Publishers 1. Introduction Strontium

Iglesia, Enrique

399

Chemical Expansion and Frozen-In Oxygen Vacancies in Pr-Doped Ceria  

E-Print Network [OSTI]

Doped CeO2 is a promising candidate for solid oxide fuel cell electrolyte and electrode applications because of its high ionic conductivity and reduction/oxidation behavior at intermediate temperatures. Its electronic and ...

Kuru, Yener

2011-01-01T23:59:59.000Z

400

Negative differential resistance behavior in phosphorus-doped armchair graphene nanoribbon junctions  

SciTech Connect (OSTI)

In this present work, we investigate the electronic transport properties of phosphorus-doped armchair graphene nanoribbon (AGNR) junctions by employing nonequilibrium Green's functions in combination with the density-function theory. Two phosphorus (P) atoms are considered to substitute the central carbon atom with the different width of AGNRs. The results indicate that the electronic transport behaviors are strongly dependent on the width of the P-doped graphene nanoribbons. The current-voltage characteristics of the doped AGNR junctions reveal an interesting negative differential resistance (NDR) and exhibit three distinct family (3 n, 3 n + 1, 3 n + 2) behaviors. These results display that P doping is a very good way to achieve NDR of the graphene nanoribbon devices.

Zhou, Yuhong [School of Optical and Electronic Information, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wenhua College, Huzhong University of Science and Technology, Wuhan City, Hubei Province 430074 (China); Zhang, Daoli, E-mail: zhang-daoli@hust.edu.cn; Zhang, Jianbing; Miao, Xiangshui [School of Optical and Electronic Information, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Ye, Cong [Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062 (China)

2014-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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

Electronic and magnetic properties of Fe and Mn doped two dimensional hexagonal germanium sheets  

SciTech Connect (OSTI)

Using first principles density functional theory calculations, the present paper reports systematic total energy calculations of the electronic properties such as density of states and magnetic moment of pristine and iron and manganese doped two dimensional hexagonal germanium sheets.

Soni, Himadri R., E-mail: himadri.soni@gmail.com; Jha, Prafulla K., E-mail: himadri.soni@gmail.com [Department of Physics, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar-364001 (India)

2014-04-24T23:59:59.000Z

402

Engineering the magnetic properties of the Mn13 cluster by doping  

E-Print Network [OSTI]

With a goal to produce a giant magnetic moment in a Mn13 cluster that will be useful for practical applications, we have considered the structure and magnetic properties of a pure Mn13 cluster and substitutionally doped ...

Datta, Soumendu

403

acid-doped polybenzimidazole membranes: Topics by E-print Network  

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

R. Daik; A. Musa 8 Comparative study of the break in process of post doped and sol-gel high temperature proton exchange membrane fuel cells Energy Storage, Conversion and...

404

E-Print Network 3.0 - aluminum doped zinc Sample Search Results  

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

and Ecology 10 Growth and photoluminescence studies of Zn-doped AlN epilayers N. Nepal, M. L. Nakarmi, H. U. Jang, J. Y. Lin, and H. X. Jianga Summary: Growth and...

405

E-Print Network 3.0 - aluminum-doped zinc oxide Sample Search...  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: aluminum-doped zinc oxide Page: << < 1 2 3 4 5 > >> 1 Introduction Nanodevices are supposed to...

406

Understanding the viability of impurity-band photovoltaics : a case study of S-doped Si  

E-Print Network [OSTI]

This thesis explores the electronic structure, optical properties, and carrier lifetimes in silicon that is doped with sulfur beyond the equilibrium solid solubility limit, with a focus on applications as an absorber layer ...

Sullivan, Joseph Timothy, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

407

High-Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts  

E-Print Network [OSTI]

by using high work function Pd contacts along with degenerate surface doping of the contacts by patterned by the gate electrode.3 For sub-5 nm gate lengths, this corresponds to channel materials with only 1-2 atomic

California at Irvine, University of

408

Accurate potential drop sheet resistance measurements of laser-doped areas in semiconductors  

SciTech Connect (OSTI)

It is investigated how potential drop sheet resistance measurements of areas formed by laser-assisted doping in crystalline Si wafers are affected by typically occurring experimental factors like sample size, inhomogeneities, surface roughness, or coatings. Measurements are obtained with a collinear four point probe setup and a modified transfer length measurement setup to measure sheet resistances of laser-doped lines. Inhomogeneities in doping depth are observed from scanning electron microscope images and electron beam induced current measurements. It is observed that influences from sample size, inhomogeneities, surface roughness, and coatings can be neglected if certain preconditions are met. Guidelines are given on how to obtain accurate potential drop sheet resistance measurements on laser-doped regions.

Heinrich, Martin, E-mail: mh.seris@gmail.com [Solar Energy Research Institute of Singapore, National University of Singapore, Singapore 117574 (Singapore); NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore 117456 (Singapore); Kluska, Sven; Binder, Sebastian [Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, D-79110 Freiburg (Germany); Hameiri, Ziv [The School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, Sydney NSW 2052 (Australia); Hoex, Bram [Solar Energy Research Institute of Singapore, National University of Singapore, Singapore 117574 (Singapore); Aberle, Armin G. [Solar Energy Research Institute of Singapore, National University of Singapore, Singapore 117574 (Singapore); NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore 117456 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117456 (Singapore)

2014-10-07T23:59:59.000Z

409

Silicon-germanium saturable absorbers and erbium-doped waveguides for integrated mode-locked lasers  

E-Print Network [OSTI]

In this thesis, Silicon-Germanium (SiGe) Saturable Bragg Reflectors (SBR) and Erbium-doped waveguide chips are fabricated and characterized as crucial components for integration of a mode-locked laser on a Si-chip. The ...

Byun, Hyunil

2006-01-01T23:59:59.000Z

410

Dielectric and electromechanical properties of barium and zirconium co-doped sodium bismuth titanate  

E-Print Network [OSTI]

Compositional exploration was conducted within the alkaline bismuth titanate system by doping on the A- and B- sites with Ba?² and Zr??, respectively. Results on the phase, dielectric and electromechanical properties of ...

Sheets, Sossity A. (Sossity Amber), 1973-

2000-01-01T23:59:59.000Z

411

Ultra High p-doping Material Research for GaN Based Light Emitters  

SciTech Connect (OSTI)

The main goal of the Project is to investigate doping mechanisms in p-type GaN and AlGaN and controllably fabricate ultra high doped p-GaN materials and epitaxial structures. Highly doped p-type GaN-based materials with low electrical resistivity and abrupt doping profiles are of great importance for efficient light emitters for solid state lighting (SSL) applications. Cost-effective hydride vapor phase epitaxial (HVPE) technology was proposed to investigate and develop p-GaN materials for SSL. High p-type doping is required to improve (i) carrier injection efficiency in light emitting p-n junctions that will result in increasing of light emitting efficiency, (ii) current spreading in light emitting structures that will improve external quantum efficiency, and (iii) parameters of Ohmic contacts to reduce operating voltage and tolerate higher forward currents needed for the high output power operation of light emitters. Highly doped p-type GaN layers and AlGaN/GaN heterostructures with low electrical resistivity will lead to novel device and contact metallization designs for high-power high efficiency GaN-based light emitters. Overall, highly doped p-GaN is a key element to develop light emitting devices for the DOE SSL program. The project was focused on material research for highly doped p-type GaN materials and device structures for applications in high performance light emitters for general illumination P-GaN and p-AlGaN layers and multi-layer structures were grown by HVPE and investigated in terms of surface morphology and structure, doping concentrations and profiles, optical, electrical, and structural properties. Tasks of the project were successfully accomplished. Highly doped GaN materials with p-type conductivity were fabricated. As-grown GaN layers had concentration N{sub a}-N{sub d} as high as 3 x 10{sup 19} cm{sup -3}. Mechanisms of doping were investigated and results of material studies were reported at several International conferences providing better understanding of p-type GaN formation for Solid State Lighting community. Grown p-type GaN layers were used as substrates for blue and green InGaN-based LEDs made by HVPE technology at TDI. These results proved proposed technical approach and facilitate fabrication of highly conductive p-GaN materials by low-cost HVPE technology for solid state lighting applications. TDI has started the commercialization of p-GaN epitaxial materials.

Vladimir Dmitriev

2007-06-30T23:59:59.000Z

412

p-Doping limit and donor compensation in CdTe polycrystalline thin film solar cells  

E-Print Network [OSTI]

p-Doping limit and donor compensation in CdTe polycrystalline thin film solar cells Ken K. Chin n Department of Physics and Apollo CdTe Solar Energy Research Center, NJIT, Newark, NJ 07058, USA a r t i c l e May 2010 Keywords: CdTe p-Doping Hole density Non-shallow Acceptor Activation energy a b s t r a c

413

The Effects and Applications of Erbium Doped Fiber Fabry-Perot Interferometers  

E-Print Network [OSTI]

THE EFFECTS AND APPLICATIONS OF ERBIUM DOPED FIBER FABRY-PEROT INTERFEROMETERS A Thesis by JUSTIN KEITH TAYLOR Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 2009 Major Subject: Electrical Engineering THE EFFECTS AND APPLICATIONS OF ERBIUM DOPED FIBER FABRY-PEROT INTERFEROMETERS A Thesis by JUSTIN KEITH TAYLOR Submitted to the Office of Graduate...

Taylor, Justin K.

2010-07-14T23:59:59.000Z

414

Iron-Doped Carbon Aerogels: Novel Porous Substrates for Direct Growth of Carbon Nanotubes  

SciTech Connect (OSTI)

We present the synthesis and characterization of Fe-doped carbon aerogels (CAs) and demonstrate the ability to grow carbon nanotubes directly on monoliths of these materials to afford novel carbon aerogel-carbon nanotube composites. Preparation of the Fe-doped CAs begins with the sol-gel polymerization of the potassium salt of 2,4-dihydroxybenzoic acid with formaldehyde, affording K{sup +}-doped gels that can then be converted to Fe{sup 2+}- or Fe{sup 3+}-doped gels through an ion exchange process, dried with supercritical CO{sub 2} and subsequently carbonized under an inert atmosphere. Analysis of the Fe-doped CAs by TEM, XRD and XPS revealed that the doped iron species are reduced during carbonization to form metallic iron and iron carbide nanoparticles. The sizes and chemical composition of the reduced Fe species were related to pyrolysis temperature as well as the type of iron salt used in the ion exchange process. Raman spectroscopy and XRD analysis further reveal that, despite the presence of the Fe species, the CA framework is not significantly graphitized during pyrolysis. The Fe-doped CAs were subsequently placed in a thermal CVD reactor and exposed to a mixture of CH{sub 4} (1000 sccm), H{sub 2} (500 sccm), and C{sub 2}H{sub 4} (20 sccm) at temperatures ranging from 600 to 800 C for 10 minutes, resulting in direct growth of carbon nanotubes on the aerogel monoliths. Carbon nanotubes grown by this method appear to be multiwalled ({approx}25 nm in diameter and up to 4 mm long) and grow through a tip-growth mechanism that pushes catalytic iron particles out of the aerogel framework. The highest yield of CNTs were grown on Fe-doped CAs pyrolyzed at 800 C treated at CVD temperatures of 700 C.

Steiner, S A; Baumann, T F; Kong, J; Satcher, J H; Dresselhaus, M S

2007-02-15T23:59:59.000Z

415

Luminescent studies of fluorescent chromophore-doped silica aerogels for flat panel display applications  

SciTech Connect (OSTI)

The remarkable optical and electronic properties of doped and undoped silica aerogels establish their utility as unique, mulitfunctional host materials for fluorescent dyes and other luminescent materials for display and imaging applications. We present results on the photoluminescence, absorption, and photoluminescence excitation spectra of undoped silica aerogels and aerogels doped with Er{sup 3+}, rhodamine 6G (R6G), and fluorescein. 4 refs., 12 figs.

Glauser, S.A.C. [California Univ., Davis, CA (United States). Dept. of Applied Science; Lee, H.W.H. [Lawrence Livermore National Lab., CA (United States)

1997-04-01T23:59:59.000Z

416

Hydrothermal synthesis and characteristics of anions-doped calcium molybdate red powder phosphors  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: • Four anion-doped CaMoO{sub 4}:Eu{sup 3+} red phosphors were prepared by hydrothermal approach. • Some samples exhibit nearly spherical morphology and well-distributed fine particles. • The red luminescence can be obviously enhanced after certain amount of anion doping. • The improved phosphor system is a potential candidate for white LED applications. - Abstract: Applying hydrothermal and subsequent heat-treatment process, CaMoO{sub 4}:Eu{sup 3+} was doped with four anions (SiO{sub 3}{sup 2?}, PO{sub 4}{sup 3?}, SO{sub 4}{sup 2?} and ClO{sub 3}{sup ?}) to prepare fine red powder phosphors. The introduction of small amount of anions into the host had little influence on the structure, which was confirmed by X-ray diffraction patterns. The anion-doped phosphor samples (except SiO{sub 3}{sup 2?}) exhibited nearly spherical morphology, and the particle sizes were in the range of 0.3–0.4 ?m for SO{sub 4}{sup 2?}-doped samples, and 0.8–1.2 ?m for PO{sub 4}{sup 3?} and ClO{sub 3}{sup ?}-doped samples. Excited with 395 nm near-UV light, all samples showed typical Eu{sup 3+} red emission at 615 nm, and PO{sub 4}{sup 3?}, SO{sub 4}{sup 2?} and ClO{sub 3}{sup ?}-doped samples enhanced the red luminescence as compared with the individual CaMoO{sub 4}:Eu{sup 3+} sample. In particular, relative emission intensity for optimum ClO{sub 3}{sup ?}-doped phosphors reached more than 6-fold that of the commercial red phosphor, which is highly desirable for the powder phosphors used in the solid-state lighting industry.

Shi, Shikao, E-mail: ssk02@mails.tsinghua.edu.cn [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024 (China); Zhang, Yan; Liu, Qing [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024 (China); Zhou, Ji [State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China)

2013-10-15T23:59:59.000Z

417

Doping Cu{sub 2}O in Electrolyte Solution: Dopant Incorporation, Atomic Structures and Electrical Properties  

SciTech Connect (OSTI)

We have pursued a number of research activities between April 2010 and April 2011: ? A detailed study on n-type doping in Cu2O by Br; ? An analysis of natural resource limitations to terawatt-scale solar cells; ? Attempt to achieve a 1.4-eV direct band gap in Ni sulfides (NiSx); ? First-principles studies of doping in Cu2O and electronic structures of NiSx.

Tao, Meng; Zhang, Qiming

2013-11-24T23:59:59.000Z

418

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

419

Controlling ferromagnetism of (In,Fe)As semiconductors by electron doping  

SciTech Connect (OSTI)

Based on experimental results, using the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method and Monte Carlo simulation, we study the mechanism of ferromagnetic behavior of (In,Fe)As. We show that with doped Be atoms occupying in interstitial sites, chemical pair interactions between atoms and magnetic exchange interactions between Fe atoms change due to electron concentration. Therefore, by controlling the doping process, magnetic behavior of (In,Fe)As is controlled and ferromagnetism is observed in this semiconductor.

Dang Vu, Nguyen; Fukushima, Tetsuya; Katayama-Yoshida, Hiroshi [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Sato, Kazunori [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2014-02-21T23:59:59.000Z

420

Vibration responses of h-BN sheet to charge doping and external strain  

SciTech Connect (OSTI)

Based on density functional theory and density functional perturbation theory calculations, we systematically investigate the vibration responses of h-BN sheet to charge doping and external strains. It is found that under hole doping, the phonon frequencies of the ZO and TO branches at different wave vector q shift linearly with different slopes. Under electron doping, although the phonon frequencies shift irregularly, the shifting values are different at different phonon wave vectors. Interestingly, we find that external strain can restrain the irregular vibration responses of h-BN sheet to electron doping. The critical factor is revealed to be the relative position of the nearly free electron and boron p{sub z} states of h-BN sheet. Under external strains, the vibration responses of h-BN sheet are also found to be highly dependent on the phonon branches. Different vibration modes at different q points are revealed to be responsible for the vibration responses of h-BN sheet to charge doping and external strain. Our results point out a new way to detect the doping or strain status of h-BN sheet by measuring the vibration frequencies at different wave vector.

Yang, Wei; Yang, Yu; Zheng, Fawei [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)] [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Zhang, Ping, E-mail: zhang-ping@iapcm.ac.cn [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China) [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Beijing Computational Science Research Center, Beijing 100084 (China)

2013-12-07T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.


421

Electronic structure evolution in doping of fullerene (C{sub 60}) by molybdenum trioxide  

SciTech Connect (OSTI)

Molybdenum oxide doping of fullerene has been investigated using ultraviolet photoemission spectroscopy (UPS), X-ray photoemission spectroscopy (XPS), and inverse photoemission spectroscopy (IPES). The lowest unoccupied molecular orbital and the highest occupied molecular orbital (HOMO) can be observed directly with IPES and UPS. It is observed that the Fermi level position in fullerene is modified by molybdenum oxide doping, and the HOMO onset is shifted to less than 0.3?eV below the Fermi level. The energy level shift is found to saturate at doping ratio of 18%. Till this stage, the shift depends on the doping concentration in a semi-logarithmic scale, with a slope substantially higher than that of the traditional semiconductor theory. The XPS results indicate that charge transfer continues beyond the energy level shift saturation till the doping ratio reaches 66% as evidenced by the Mo{sup 5+} component. At higher doping concentration, there is more Mo{sup 6+} component, which indicates the saturation of the charge transfer between MoO{sub x} and C{sub 60}.

Wang, Chenggong [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Gao, Yongli, E-mail: ygao@pas.rochester.edu [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, College of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China)

2014-09-15T23:59:59.000Z

422

Effect of doping on growth and field emission properties of spherical carbon nanotube tip placed over cylindrical surface  

SciTech Connect (OSTI)

Theoretical investigations to study the effect of doping of hetero-atoms on the growth and field emission properties of Carbon Nanotubes (CNTs) tip placed over a cylindrical surface in complex plasma have been carried out. A theoretical model incorporating kinetics of plasma species such as electron, ions, and neutral atoms including doping elements like nitrogen (N) and boron (B) and energy balance of CNTs in a complex plasma has been developed. The effect of doping elements of N and B on the growth of CNTs, namely, the tip radius has been carried out for typical glow discharge plasma parameters. It is found that N and B as doping elements affect the radius of CNTs extensively. We obtain small radii of CNT doped with N and large radius of CNT doped with B. The field emission characteristics from CNTs have therefore been suggested on the basis of results obtained. Some of theoretical results are in compliance with the existing experimental observations.

Santolia, Isha; Tewari, Aarti; Sharma, Suresh C.; Sharma, Rinku [Department of Applied Physics, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi 110 042 (India)

2014-06-15T23:59:59.000Z

423

Fabrication of Chemically Doped, High Upper Critical Field Magnesium Diboride Superconducting Wires  

SciTech Connect (OSTI)

Controlled chemical doping of magnesium diboride (MgB2) has been shown to substantially improve its superconducting properties to the levels required for high field magnets, but the doping is difficult to accomplish through the usual route of solid state reaction and diffusion. Further, superconducting cables of MgB2 are difficult to fabricate because of the friable nature of the material. In this Phase I STTR project, doped and undoped boron fibers were made by chemical vapor deposition (CVD). Several >100m long batches of doped and undoped fiber were made by CVD codeposition of boron plus dopants. Bundles of these fibers infiltrated with liquid magnesium and subsequently converted to MgB2 to form Mg-MgB2 metal matrix composites. In a parallel path, doped boron nano-sized powder was produced by a plasma synthesis technique, reacted with magnesium to produce doped MgB2 superconducting ceramic bodies. The doped powder was also fabricated into superconducting wires several meters long. The doped boron fibers and powders made in this program were fabricated into fiber-metal composites and powder-metal composites by a liquid metal infiltration technique. The kinetics of the reaction between boron fiber and magnesium metal was investigated in fiber-metal composites. It was found that the presence of dopants had significantly slowed the reaction between magnesium and boron. The superconducting properties were measured for MgB2 fibers and MgB2 powders made by liquid metal infiltration. Properties of MgB2 products (Jc, Hc2) from Phase I are among the highest reported to date for MgB2 bulk superconductors. Chemically doped MgB2 superconducting magnets can perform at least as well as NbTi and NbSn3 in high magnetic fields and still offer an improvement over the latter two in terms of operating temperature. These characteristics make doped MgB2 an effective material for high magnetic field applications, such as magnetic confined fusion, and medical MRI devices. Developing fusion as an energy source will dramatically reduce energy costs, global warming, and radioactive waste. Cheaper and more efficient medical MRI devices could lower examination costs, find potential health problems earlier, and thus also benefit society as a whole. Other potential commercial applications for this material are devices for the generation and storage of electrical power, thus lowering the cost of delivered electricity.

Marzik, James, V.

2005-10-13T23:59:59.000Z

424

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

425

The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents  

SciTech Connect (OSTI)

Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs.

Liburdy, R.P.; de Manincor, D.; Fingado, B.

1989-09-01T23:59:59.000Z

426

Selective area growth of Bernal bilayer epitaxial graphene on 4H-SiC (0001) substrate by electron-beam irradiation  

SciTech Connect (OSTI)

We report selective area growth of large area homogeneous Bernal stacked bilayer epitaxial graphene (BLEG) on 4H-SiC (0001) substrate by electron-beam irradiation. Sublimation of Si occurs by energetic electron irradiations on SiC surface via breaking of Si–C bonds in the localized region, which allows the selective growth of graphene. Raman measurements ensure the formation of homogeneous BLEG with weak compressive strain of ?0.08%. The carrier mobility of large area BLEG is ?5100?cm{sup 2}?V{sup ?1}?s{sup ?1} with a sheet carrier density of 2.2?×?10{sup 13}?cm{sup ?2}. Current-voltage measurements reveal that BLEG on 4H-SiC forms a Schottky junction with an operation at mA level. Our study reveals that the barrier height at the Schottky junction is low (?0.58?eV) due to the Fermi-level pinning above the Dirac point.

Dharmaraj, P.; Jeganathan, K., E-mail: kjeganathan@yahoo.com [Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India); Parthiban, S.; Kwon, J. Y. [School of Integrated Technology and Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Gautam, S.; Chae, K. H. [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Asokan, K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

2014-11-03T23:59:59.000Z

427

Effect of carrier doping on the formation and collapse of magnetic polarons in lightly hole-doped La1-xSrxCoO3  

SciTech Connect (OSTI)

We investigate the doping dependence of the nanoscale electronic and magnetic inhomogeneities in the hole-doping range 0.002 < x < 0.1 of cobalt based perovskites, La{sub 1-x}Sr{sub x}CoO{sub 3}. Using single-crystal inelastic neutron scattering and magnetization measurements we show that the lightly doped system exhibits magnetoelectronic phase separation in the form of spin-state polarons. Higher hole doping leads to a decay of spin-state polarons in favor of larger scale magnetic clusters, due to competing ferromagnetic correlations of Co{sup 3+} ions which are formed by neighboring polarons. The present data give evidence for two regimes of magnetoelectronic phase separation in this system: (i) x {approx}< 0.05, dominated by ferromagnetic intrapolaron interactions, and (ii) x {approx}> 0.05, dominated by Co{sup 3+}-Co{sup 3+} intracluster interactions. Our conclusions are in good agreement with a recently proposed model of the phase separation in cobalt perovskites.

Podlesnyak, Andrey A [ORNL; Ehlers, Georg [ORNL; Frontzek, Matthias D [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL); Furrer, Albert [Laboratory for Neutron Scattering ETHZ & PSI; Straessle, Thierry [Laboratory for Neutron Scattering ETHZ & PSI; Pomjakushina, Ekaterina [Paul Scherrer Institut, Villigen, Switzerland; Conder, Kazimierz [Paul Scherrer Institut, Villigen, Switzerland; Demmel, F. [ISIS Facility, Rutherford Appleton Laboratory; Khomskii, D. I. [Universitat zu Koln, Koln, Germany

2011-01-01T23:59:59.000Z

428

DEVELOPMENT OF DOPED NANOPOROUS CARBONS FOR HYDROGEN STORAGE  

SciTech Connect (OSTI)

Hydrogen storage materials based on the hydrogen spillover mechanism onto metal-doped nanoporous carbons are studied, in an effort to develop materials that store appreciable hydrogen at ambient temperatures and moderate pressures. We demonstrate that oxidation of the carbon surface can significantly increase the hydrogen uptake of these materials, primarily at low pressure. Trace water present in the system plays a role in the development of active sites, and may further be used as a strategy to increase uptake. Increased surface density of oxygen groups led to a significant enhancement of hydrogen spillover at pressures less than 100 milibar. At 300K, the hydrogen uptake was up to 1.1 wt. % at 100 mbar and increased to 1.4 wt. % at 20 bar. However, only 0.4 wt% of this was desorbable via a pressure reduction at room temperature, and the high lowpressure hydrogen uptake was found only when trace water was present during pretreatment. Although far from DOE hydrogen storage targets, storage at ambient temperature has significant practical advantages oner cryogenic physical adsorbents. The role of trace water in surface modification has significant implications for reproducibility in the field. High-pressure in situ characterization of ideal carbon surfaces in hydrogen suggests re-hybridization is not likely under conditions of practical interest. Advanced characterization is used to probe carbon-hydrogen-metal interactions in a number of systems and new carbon materials have been developed.

Angela D. Lueking; Qixiu Li; John V. Badding; Dania Fonseca; Humerto Gutierrez; Apurba Sakti; Kofi Adu; Michael Schimmel

2010-03-31T23:59:59.000Z

429

Microwave sintering of pure and doped nanocrystalline alumina compacts  

SciTech Connect (OSTI)

A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz is being used to investigate sintering of pure and doped nanocrystalline alumina. The purpose of these experiments is to determine the effect of additives on the sintering process in the nanocrystalline regime. Using the sol-gel method, high purity Al{sub 2}O{sub 3} nanocrystalline powders were synthesized. These powders were calcined at 700 C and then CIP`ed to 414 MPa, producing 0.4 in. diameter, 0.25 in. high cylindrical compacts. The compacts were heated in the microwave furnace to temperatures between 1,100 C to approximately 1,800 C and were then brought back to room temperature using a triangular heating profile of about 30 minutes duration. A two-color IR pyrometer was used to monitor the surface temperature of the workpiece. The additives tested in this work lowered the temperature needed for densification but this effect was offset by increased grain growth. Initial grain growth from <5 nm to {approximately}50 nm was closely correlated with the {gamma} to {alpha}-alumina phase transition.

Bruce, R.W. [SFA, Inc., Largo, MD (United States); Fliflet, A.W.; Lewis, D. III; Rayne, R.J.; Bender, B.A.; Chow, G.M.; Schoen, P.E. [Naval Research Lab., Washington, DC (United States); Kurihara, L.K. [Georgetown Univ., Washington, DC (United States). Dept. of Biochemistry

1996-12-31T23:59:59.000Z

430

Method of preparing doped oxide catalysts for lean NOx exhaust  

DOE Patents [OSTI]

The lean NOx catalyst includes a substrate, an oxide support material, preferably .gamma.-alumina deposited on the substrate and a metal or metal oxide promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium cerium, and vanadium, and oxides thereof, and any combinations thereof. The .gamma.-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between 80 and 350 m.sup.2 /g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to about 0.2 weight percent. In a preferred embodiment the .gamma.-alumina is prepared by a sol-gel method, with the metal doping of the .gamma.-alumina preferably accomplished using an incipient wetness impregnation technique.

Park, Paul W.

2004-03-09T23:59:59.000Z

431

Study of Radioactive Impurities in Neutron Transmutation Doped Germanium  

E-Print Network [OSTI]

A program to develop low temperature (mK) sensors with neutron transmutation doped Ge for rare event studies with a cryogenic bolometer has been initiated. For this purpose, semiconductor grade Ge wafers are irradiated with thermal neutron flux from Dhruva reactor at BARC, Mumbai. Spectroscopic studies of irradiated samples have revealed that the environment of the capsule used for irradiating the sample leads to significant levels of $^{65}$Zn, $^{110}$Ag and $^{182}$Ta impurities, which can be reduced by chemical etching of approximately $\\sim50 \\mu$m thick surface layer. From measurements of the etched samples in the low background counting setup, activity due to trace impurities of $^{123}$Sb in bulk Ge is estimated to be $\\sim$ 1 Bq/gm after irradiation. These estimates indicate that in order to use the NTD Ge sensors for rare event studies, a cool down period of $\\sim$ 2 years would be necessary to reduce the radioactive background to $\\le$ 1 mBq/gm.

S. Mathimalar; N. Dokania; V. Singh; V. Nanal; R. G. Pillay; A. Shrivastava; K. C. Jagadeesan; S. V. Thakare

2014-11-27T23:59:59.000Z

432

Remarkable Strontium B-Site Occupancy in Ferroelectric Pb(Zr1-xTix)O3 Solid Solutions Doped with Cryolite-Type Strontium Niobate  

E-Print Network [OSTI]

Doped with Cryolite-Type Strontium Niobate” April 26, 2007Doped with Cryolite-Type Strontium Niobate” April 26, 2007and J. P. Loup, “Le Niobate de Strontium Sr 4 Nb 2 O 9 : Une

Feltz, A.; Schmidt-Winkel, P.; Schossman, M.; Booth, C.H.; Albering, J.

2007-01-01T23:59:59.000Z

433

D{sup 0} magnetism in Ca doped narrow carbon nanotubes: First principle chirality effect study  

SciTech Connect (OSTI)

Curvature has always had crucial effects on the physical properties of narrow carbon nanotubes (CNTs) and here spin-polarized density functional calculations were employed to study electronic and magnetic properties of calcium-decorated narrow (5,5) and (9,0)CNTs with close diameters (?7?Å) and different chiralities. Our results showed that chirality had great impact on the electronic structure and magnetization of the doped CNTs. In addition, internally or externally doping of the calcium atoms was studied comparatively and although for the (9,0)CNT the internal doping was the most stable configuration, which involves a novel kind of spin-polarization originated from Ca-4s electrons, but for the (5,5)tube the external doping was the most stable one without any spin-polarization. On the other hand, calcium doping in the center of the (5,5)CNT was an endothermic process and led to the spin-polarization of unoccupied Ca-3d orbitals via direct exchange interaction between adjacent Ca atoms. In the considered systems, the existence of magnetization in the absence of any transition-metal elements was an example of valuable d{sup 0} magnetism title.

Hajiheidari, F.; Khoshnevisan, B., E-mail: b.khosh@kashanu.ac.ir [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Hashemifar, S. J. [Faculty of Physics, Isfahan University of technology, 84156-83111 Isfahan (Iran, Islamic Republic of)

2014-06-21T23:59:59.000Z

434

Formation of Carbon Nanostructures in Cobalt- and Nickel-Doped Carbon Aerogels  

SciTech Connect (OSTI)

We have prepared carbon aerogels (CAs) doped with cobalt or nickel through sol-gel polymerization of formaldehyde with the potassium salt of 2,4-dihydroxybenzoic acid, followed by ion-exchange with M(NO{sub 3}){sub 2} (where M = Co{sup 2+} or Ni{sup 2+}), supercritical drying with liquid CO{sub 2} and carbonization at temperatures between 400 C and 1050 C under an N{sub 2} atmosphere. The nanostructures of these metal-doped carbon aerogels were characterized by elemental analysis, nitrogen adsorption, high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Metallic nickel and cobalt nanoparticles are generated during the carbonization process at about 400 C and 450 C, respectively, forming nanoparticles that are {approx}4 nm in diameter. The sizes and size dispersion of the metal particles increase with increasing carbonization temperatures for both materials. The carbon frameworks of the Ni- and Co-doped aerogels carbonized below 600 C mainly consist of interconnected carbon particles with a size of 15 to 30 nm. When the samples are pyrolyzed at 1050 C, the growth of graphitic nanoribbons with different curvatures is observed in the Ni and Co-doped carbon aerogel materials. The distance of graphite layers in the nanoribbons is about 0.38 nm. These metal-doped CAs retain the overall open cell structure of metal-free CAs, exhibiting high surface areas and pore diameters in the micro and mesoporic region.

Fu, R; Baumann, T F; Cronin, S; Dresselhaus, G; Dresselhaus, M; Satcher, Jr., J H

2004-11-09T23:59:59.000Z

435

Pulsed laser ablation growth and doping of epitaxial compound semiconductor films  

SciTech Connect (OSTI)

Pulsed laser ablation (PLA) has several characteristics that are potentially attractive for the growth and doping of chemically complex compound semiconductors including (1) stoichiometric (congruent) transfer of composition from target to film, (2) the use of reactive gases to control film composition and/or doping via energetic-beam-induced reactions, and (3) low-temperature nonequilibrium phase formation in the laser-generated plasma ``plume.`` However, the electrical properties of compound semiconductors are far more sensitive to low concentrations of defects than are the oxide metals/ceramics for which PLA has been so successful. Only recently have doped epitaxial compound semiconductor films been grown by PLA. Fundamental studies are being carried out to relate film electrical and microstructural properties to the energy distribution of ablated species, to the temporal evolution of the ablation pulse in ambient gases, and to beam assisted surface and/or gas-phase reactions. In this paper the authors describe results of ex situ Hall effect, high-resolution x-ray diffraction, transmission electron microscopy, and Rutherford backscattering measurements that are being used in combination with in situ RHEED and time-resolved ion probe measurements to evaluate PLA for growth of doped epitaxial compound semiconductor films and heterostructures. Examples are presented and results analyzed for doped II-VI, I-III-VI, and column-III nitride materials grown recently in this and other laboratories.

Lowndes, D.H.; Rouleau, C.M.; Geohegan, D.B.; Budai, J.D.; Poker, D.B. [Oak Ridge National Lab., TN (United States). Solid State Div.; Puretzky, A.A. [Inst. of Spectroscopy, Troitsk (Russian Federation); Strauss, M.A.; Pedraza, A.J.; Park, J.W. [Univ. of Tennessee, Knoxville, TN (United States)

1995-12-01T23:59:59.000Z

436

Magnetic properties of transition metal doped AlN nanosheet: First-principle studies  

SciTech Connect (OSTI)

We carry out our first-principles calculations within density functional theory to study the 3d transition metal (TM) doped AlN nanosheets. The calculated results indicate that a stoichiometric AlN nanosheet is graphene-like structure and nonmagnetic. The TM impurities can induce magnetic moments, localized mainly on the 3d TM atoms and neighboring N atoms. Our calculated results of TM-doped nanosheet systems indicate a strong interaction between 3d orbit of TM atom and the 2p orbit of N atoms. In addition, the Mn- and Ni-doped AlN nanosheet with half-metal characters seems to be good candidates for spintronic applications. When substituting two Al atoms, the relative energies of the states between ferromagnetic and antiferromagnetic coupling are investigated sufficiently. The exchange coupling of Co- and Ni-doped AlN nanosheets exhibits a transformation with different distances of two TM atoms and that of Cr-, Mn-, and Fe-doped AlN nanosheets is not changed.

Shi, Changmin; Qin, Hongwei, E-mail: qin-hw@vip.163.com; Zhang, Yongjia; Hu, Jifan; Ju, Lin [School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100 (China)

2014-02-07T23:59:59.000Z

437

Nitrogen doping of chemical vapor deposition grown graphene on 4H-SiC (0001)  

SciTech Connect (OSTI)

We present optical, electrical, and structural properties of nitrogen-doped graphene grown on the Si face of 4H-SiC (0001) by chemical vapor deposition method using propane as the carbon precursor and N{sub 2} as the nitrogen source. The incorporation of nitrogen in the carbon lattice was confirmed by X-ray photoelectron spectroscopy. Angle-resolved photoemission spectroscopy shows carrier behavior characteristic for massless Dirac fermions and confirms the presence of a graphene monolayer in the investigated nitrogen-doped samples. The structural and electronic properties of the material were investigated by Raman spectroscopy. A systematical analysis of the graphene Raman spectra, including D, G, and 2D bands, was performed. In the case of nitrogen-doped samples, an electron concentration on the order of 5–10 × 10{sup 12}?cm{sup ?2} was estimated based upon Raman and Hall effect measurements and no clear dependence of the carrier concentration on nitrogen concentration used during growth was observed. This high electron concentration can be interpreted as both due to the presence of nitrogen in graphitic-like positions of the graphene lattice as well as to the interaction with the substrate. A greater intensity of the Raman D band and increased inhomogeneity, as well as decreased electron mobility, observed for nitrogen-doped samples, indicate the formation of defects and a modification of the growth process induced by nitrogen doping.

Urban, J. M.; Binder, J.; Wysmo?ek, A. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); D?browski, P.; Strupi?ski, W. [Institute of Electronic Materials Technology, ul. Wólczy?ska 133, 01-919 Warsaw (Poland); Kopciuszy?ski, M.; Ja?ochowski, M. [Institute of Physics, Maria Curie-Sk?odowska University, pl. M. Curie-Sk?odowskiej 1, 20-031 Lublin (Poland); Klusek, Z. [Faculty of Physics and Applied Informatics, University of ?ód?, ul. Pomorska 149/153, 90-236 ?ód? (Poland); Baranowski, J. M. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wólczy?ska 133, 01-919 Warsaw (Poland)

2014-06-21T23:59:59.000Z

438

Highmobility inverted selectively doped heterojunctions Hadas Shtrikman, M. Heiblum, K. Seo, D. E. Galbi, and L. Osterling  

E-Print Network [OSTI]

Highmobility inverted selectively doped heterojunctions Hadas Shtrikman, M. Heiblum, K. Seo, D. E in inverted GaAsAlGaAs heterojunctions Appl. Phys. Lett. 52, 1268 (1988); 10.1063/1.99176 High mobility: 132.76.50.6 On: Thu, 10 Apr 2014 16:05:40 #12;High-mobility inverted selectively doped heterojunctions

Heiblum, Mordehai "Moty"

439

H.sub.2O doped WO.sub.3, ultra-fast, high-sensitivity hydrogen sensors  

DOE Patents [OSTI]

An ultra-fast response, high sensitivity structure for optical detection of low concentrations of hydrogen gas, comprising: a substrate; a water-doped WO.sub.3 layer coated on the substrate; and a palladium layer coated on the water-doped WO.sub.3 layer.

Liu, Ping (Denver, CO); Tracy, C. Edwin (Golden, CO); Pitts, J. Roland (Lakewood, CO); Lee, Se-Hee (Lakewood, CO)

2011-03-22T23:59:59.000Z

440

PHYSICAL REVIEW B 84, 205305 (2011) Spin-phonon coupling in single Mn-doped CdTe quantum dot  

E-Print Network [OSTI]

PHYSICAL REVIEW B 84, 205305 (2011) Spin-phonon coupling in single Mn-doped CdTe quantum dot C. L dynamics of a single Mn atom in a laser driven CdTe quantum dot is addressed theoretically. Recent of single Mn-doped CdTe dots, information about the quantum spin state of a single Mn atom is extracted from

Paris-Sud XI, Université de

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441

Effect of the Doping Ion on the Electrical Response of a Free-Standing Polypyrrole Strip Subjected to Different Preloads  

E-Print Network [OSTI]

, a degeneration of the electrical energy vs the external stress was measured, which would seriously limit the useEffect of the Doping Ion on the Electrical Response of a Free-Standing Polypyrrole Strip Subjected they are immersed in aqueous solutions with different doping ions. By plotting the electrical energy associated

Otero, Toribio Fernández

442

Raman and conductivity studies of boron-doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films  

E-Print Network [OSTI]

-like conductivity. A complication is that polycrystalline boron-doped CVD diamond films possess grain boundariesRaman and conductivity studies of boron-doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films P.W. May a,, W.J. Ludlow a , M. Hannaway a , P.J. Heard b , J

Bristol, University of

443

Decorating anode with bamboo-like nitrogen-doped carbon nanotubes for microbial Suqin Ci a,c  

E-Print Network [OSTI]

Decorating anode with bamboo-like nitrogen-doped carbon nanotubes for microbial fuel cells Suqin Ci November 2011 Available online 20 November 2011 Keywords: Carbon nanotubes Nitrogen doping Anode Microbial. Introduction Microbial fuel cells (MFCs) are bio-electrochemical systems that directly convert chemical energy

444

Electron energy-loss spectroscopy of boron-doped layers in amorphous thin film silicon solar cells  

E-Print Network [OSTI]

Electron energy-loss spectroscopy of boron-doped layers in amorphous thin film silicon solar cells. de Bariloche, Argentina 3 ECN Solar Energy, High Tech Campus, Building 5, 5656 AE Eindhoven energy-loss spectroscopy (EELS) is used to study p-doped layers in n-i-p amorphous thin film Si solar

Dunin-Borkowski, Rafal E.

445

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

446

Effect of microstructure, grain size, and rare earth doping on the electrorheological performance of nanosized particle materials  

E-Print Network [OSTI]

and grain sizes were prepared by doping TiO2 or ZrO2 with rare earth (RE) elements, and by changingEffect of microstructure, grain size, and rare earth doping on the electrorheological performance-Hua Zhang,c Shu-Mei Chen,d Rui-Li Huange and Song Gaoa a State Key Laboratory of Rare Earth Materials

Gao, Song

447

Structure and hydrogen dynamics of pure and Ti-doped sodium alanate Jorge iguez,1,2  

E-Print Network [OSTI]

Structure and hydrogen dynamics of pure and Ti-doped sodium alanate Jorge Íñiguez,1,2 T. Yildirim,1, Honolulu, Hawaii 96822, USA (Received 2 June 2004; published 3 August 2004) We have studied the structure, energetics, and dynamics of pure and Ti-doped sodium alanate NaAlH4 , focusing on the possibility

Yildirim, Taner

448

Journal of Electronic Materials, Vol. 19, No, 4, 1990 Carbon Tetrachloride Doped AIxGa_xAS  

E-Print Network [OSTI]

Journal of Electronic Materials, Vol. 19, No, 4, 1990 Carbon Tetrachloride Doped AIx been shown to be a suitable carbon doping source for obtaining p-type GaAs grown by metalorganic chemical vapor deposition (MOCVD) with carbon acceptor concentrations in excess of 1 x 1019cm-3

Cunningham, Brian

449

TOWARDS AN ER-DOPED SI NANOCRYSTAL SENSITIZED WAVEGUIDE LASER THE THIN LINE BETWEEN GAIN AND LOSS  

E-Print Network [OSTI]

and waveguide. If the pump laser could somehow be eliminated from this scheme, the fabrication of low-cost SiTOWARDS AN ER-DOPED SI NANOCRYSTAL SENSITIZED WAVEGUIDE LASER ­ THE THIN LINE BETWEEN GAIN AND LOSS-doped SiO2, a composite material that can potentially be fabricated using a VLSI compatible process

Kik, Pieter

450

Hydrogen-doped cubic diamond and the crystal structure of n-diamond Bin Wen a,b,  

E-Print Network [OSTI]

Hydrogen-doped cubic diamond and the crystal structure of n-diamond Bin Wen a,b, , Roderick Melnik. In particular, hydrogen concen- tration dependent elastic constants and lattice parameters for the H-doped diamond have been analyzed. Our results indicate that when the hydrogen concentration is less than 19 at

Melnik, Roderick

451

Evolution of light-induced anchoring in dye-doped nematics: Experiment and model Previous Abstract | Next Abstract | Issue Table of Contents  

E-Print Network [OSTI]

Evolution of light-induced anchoring in dye-doped nematics: Experiment and model Previous Abstract |GZipped PS View MyArticles Evolution of light-induced anchoring in dye-doped nematics: Experiment was carried out to describe the evolution of light-induced anchoring in dye-doped nematic liquid crystals (LCs

Reznikov, Yuri

452

Structural study of VO {sub x} doped aluminium fluoride and aluminium oxide catalysts  

SciTech Connect (OSTI)

The structural properties of vanadium doped aluminium oxyfluorides and aluminium oxides, prepared by a modified sol-gel synthesis route, were thoroughly investigated. The influence of the preparation technique and the calcination temperature on the coordination of vanadium, aluminium and fluorine was analysed by different spectroscopic methods such as Raman, MAS NMR and ESR spectroscopy. In all samples calcined at low temperatures (350 deg. C), vanadium coexists in two oxidation states V{sup IV} and V{sup V}, with V{sup IV} as dominating species in the vanadium doped aluminium oxyfluorides. In the fluoride containing solids aluminium as well as vanadium are coordinated by fluorine and oxygen. Thermal annealing of 800 deg. C leads to an extensive reorganisation of the original matrices and to the oxidation of V{sup IV} to V{sup V} in both systems. - Graphical abstract: Structure model for VO {sub x} doped aluminium oxide.

Scheurell, Kerstin [Institute of Chemistry, Humboldt University of Berlin, Brook-Taylor-Street 2, Berlin D-12489 (Germany); Scholz, Gudrun [Institute of Chemistry, Humboldt University of Berlin, Brook-Taylor-Street 2, Berlin D-12489 (Germany); Kemnitz, Erhard [Institute of Chemistry, Humboldt University of Berlin, Brook-Taylor-Street 2, Berlin D-12489 (Germany)], E-mail: erhard.kemnitz@chemie.hu-berlin.de

2007-02-15T23:59:59.000Z

453

Origin of enhanced magnetization in rare earth doped multiferroic bismuth ferrite  

SciTech Connect (OSTI)

We report structural and magnetic properties of rare earth doped Bi{sub 0.95}R{sub 0.05} FeO{sub 3} (R?=?Y, Ho, and Er) submicron particles. Rare earth doping enhances the magnetization and the magnetization shows an increasing trend with decreasing dopant ionic radii. In contrast to the x-ray diffraction pattern, we have seen a strong evidence for the presence of rare earth iron garnets R{sub 3}Fe{sub 5}O{sub 12} in magnetization measured as a function of temperature, in selected area electron diffraction, and in Raman measurements. Our results emphasised the role of secondary phases in the magnetic property of rare earth doped BiFeO{sub 3} compounds along with the structural distortion favoring spin canting by increase in Dzyaloshinskii-Moriya exchange energy.

Nayek, C.; Thirmal, Ch.; Murugavel, P., E-mail: muruga@iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai 36 (India); Tamilselvan, A.; Balakumar, S. [National Centre for Nanoscience and Nanotechnology, University of Madras, Chennai 25 (India)

2014-02-21T23:59:59.000Z

454

Pulsed laser deposition of Mn doped CdSe quantum dots for improved solar cell performance  

SciTech Connect (OSTI)

In this work, we demonstrate (1) a facile method to prepare Mn doped CdSe quantum dots (QDs) on Zn{sub 2}SnO{sub 4} photoanodes by pulsed laser deposition and (2) improved device performance of quantum dot sensitized solar cells of the Mn doped QDs (CdSe:Mn) compared to the undoped QDs (CdSe). The band diagram of photoanode Zn{sub 2}SnO{sub 4} and sensitizer CdSe:Mn QD is proposed based on the incident-photon-to-electron conversion efficiency (IPCE) data. Mn-modified band structure leads to absorption at longer wavelengths than the undoped CdSe QDs, which is due to the exchange splitting of the CdSe:Mn conduction band by the Mn dopant. Three-fold increase in the IPCE efficiency has also been observed for the Mn doped samples.

Dai, Qilin; Wang, Wenyong, E-mail: wwang5@uwyo.edu, E-mail: jtang2@uwyo.edu; Tang, Jinke, E-mail: wwang5@uwyo.edu, E-mail: jtang2@uwyo.edu [Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071 (United States); Sabio, Erwin M. [Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071 (United States)

2014-05-05T23:59:59.000Z

455

Growth and nucleation regimes in boron doped silicon by dynamical x-ray diffraction  

SciTech Connect (OSTI)

The oxygen precipitation of highly (17.5 m? cm) and moderately (4.5 ? cm) boron (B) doped silicon (Si) crystals at 780?°C is investigated by following in-situ the evolution of diffraction Pendellösung oscillations. All samples show an initial diffusion-driven growth process which may change over into Ostwald ripening. For the highly doped sample and involving a nucleation step at 450?°C for 30?h, the precipitate density ? is enhanced by a factor of 8 as compared to the moderately doped sample. The influence of a high B concentration on ? is dramatically higher for the samples directly heated to 780?°C, where an enhancement factor of 80 is found. Considering Ostwald ripening as a second growth regime reveals consistent ripening rates and surface energies ? with those found at 900?°C in a previous publication.

Will, J., E-mail: johannes.will@fau.de; Gröschel, A.; Bergmann, C.; Weißer, M.; Magerl, A. [Crystallography and Structural Physics, University of Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany)

2014-09-15T23:59:59.000Z

456

Mg doping of GaN grown by plasma-assisted molecular beam epitaxy under nitrogen-rich conditions  

SciTech Connect (OSTI)

Acceptor doping of GaN with Mg during plasma-assisted molecular beam epitaxy, under N-rich conditions and a relatively high growth temperature of 740 deg. C, was investigated. The p-doping level steadily increases with increasing Mg flux. The highest doping level achieved, determined from Hall measurements, is 2.1x10{sup 18} cm{sup -3}. The corresponding doping efficiency and hole mobility are approx4.9% and 3.7 cm{sup 2}/V s at room temperature. Cross-sectional transmission electron microscopy and photoluminescence measurements confirm good crystalline and optical quality of the Mg-doped layers. An InGaN/GaN quantum dot light emitting diode (lambda{sub peak}=529 nm) with p-GaN contact layers grown under N-rich condition exhibits a low series resistance of 9.8 OMEGA.

Zhang Meng; Bhattacharya, Pallab; Guo Wei; Banerjee, Animesh [Department of Electrical Engineering and Computer Science, Solid-State Electronics Laboratory, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

2010-03-29T23:59:59.000Z

457

Interfacing Superconducting Qubits and Telecom Photons via a Rare-Earth Doped Crystal  

E-Print Network [OSTI]

We propose a scheme to couple short single photon pulses to superconducting qubits. An optical photon is first absorbed into an inhomogeneously broadened rare-earth doped crystal using controlled reversible inhomogeneous broadening. The optical excitation is then mapped into a spin state using a series of $\\pi$-pulses and subsequently transferred to a superconducting qubit via a microwave cavity. To overcome the intrinsic and engineered inhomogeneous broadening of the optical and spin transitions in rare earth doped crystals, we make use of a special transfer protocol using staggered $\\pi$-pulses. We predict total transfer efficiencies on the order of 90%.

Christopher O'Brien; Nikolai Lauk; Susanne Blum; Giovanna Morigi; Michael Fleischhauer

2014-07-25T23:59:59.000Z

458

Hydrogen adsorption and anomalous electronic properties of nitrogen-doped graphene  

SciTech Connect (OSTI)

We investigate hydrogen adsorption effects on stabilities and electronic properties of nitrogen defects in graphene using first-principles electronic-structure calculations within the density-functional theory. We find that the adsorption of hydrogen atoms on the pyridine-type nitrogen defects in graphene becomes energetically favorable, whereas in the case of the substitutional nitrogen defect the hydrogen adsorption becomes unfavorable. We also find that a transition from p-type to n-type doping properties occurs by hydrogen adsorption on the pyridine-type defects, suggesting that even the carrier type is controllable in nitrogen-doped graphene.

Fujimoto, Yoshitaka, E-mail: fujimoto@stat.phys.titech.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro-ku, Tokyo 152-8551 (Japan); Saito, Susumu [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro-ku, Tokyo 152-8551 (Japan); International Research Center for Nanoscience and Quantum Physics, Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro-ku, Tokyo 152-8551 (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan)

2014-04-21T23:59:59.000Z

459

Partially filled intermediate band of Cr-doped GaN films  

SciTech Connect (OSTI)

We investigated the band structure of sputtered Cr-doped GaN (GaCrN) films using optical absorption, photoelectron yield spectroscopy, and charge transport measurements. It was found that an additional energy band is formed in the intrinsic band gap of GaN upon Cr doping, and that charge carriers in the material move in the inserted band. Prototype solar cells showed enhanced short circuit current and open circuit voltage in the n-GaN/GaCrN/p-GaN structure compared to the GaCrN/p-GaN structure, which validates the proposed concept of an intermediate-band solar cell.

Sonoda, S. [Department of Electronics, Kyoto Institute of Technology, Kyoto 606-8585 (Japan)

2012-05-14T23:59:59.000Z

460

Mid infrared optical properties of Ge/Si quantum dots with different doping level  

SciTech Connect (OSTI)

Optical characterization of the Ge/Si quantum dots using equilibrium and photo-induced absorption spectroscopy in the mid-infrared spectral range was performed in this work. Equilibrium absorption spectra were measured in structures with various doping levels for different light polarizations. Photo-induced absorption spectra measured in undoped structure under interband optical excitation of non-equilibrium charge carriers demonstrate the same features as doped sample in equilibrium conditions. Hole energy spectrum was determined from the analysis of experimental data.

Sofronov, A. N.; Firsov, D. A.; Vorobjev, L. E.; Shalygin, V. A.; Panevin, V. Yu.; Vinnichenko, M. Ya. [St. Petersburg State Polytechnic University, Polytechnicheskaya str. 29, St. Petersburg (Russian Federation); Tonkikh, A. A. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Danilov, S. N. [University of Regensburg, Regensburg (Germany)

2013-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.


461

On the structural and impedance characteristics of Li- doped PEO, using n-butyl lithium in hexane as dopant  

SciTech Connect (OSTI)

Nowadays polymer based solid state electrolytes for applications in rechargeable battery systems are highly sought after materials, pursued extensively by various research groups worldwide. Numerous methods are discussed in literature to improve the fundamental properties like electrical conductivity, mechanical stability and interfacial stability of polymer based electrolytes. The application of these electrolytes in Li-ion cells is still in the amateur state, due to low ionic conductivity, low lithium transport number and the processing difficulties. The present work is an attempt to study the effects of Li doping on the structural and transport properties of the polymer electrolyte, poly-ethelene oxide (PEO) (Molecular weight: 200,000). Li doped PEO was obtained by treating PEO with n-Butyllithium in hexane for different doping concentrations. Structural characterization of the samples was done by XRD and FTIR techniques. Impedance measurements were carried out to estimate the ionic conductivity of Li doped PEO samples. It is seen that, the crystallinity of the doped PEO decreases on increasing the doping concentration. XRD and FTIR studies support this observation. It is inferred that, ionic conductivity of the sample is increasing on increasing the doping concentration since less crystallinity permits more ionic transport. Impedance measurements confirm the results quantitatively.

Anand, P. B., E-mail: anandputhirath@gmail.com, E-mail: jayalekshmi@cusat.ac.in; Jayalekshmi, S., E-mail: anandputhirath@gmail.com, E-mail: jayalekshmi@cusat.ac.in [Division for Research in Advanced Materials Department of Physics Cochin University of Science and Technology Cochin 22, Kerala (India)

2014-01-28T23:59:59.000Z

462

Computational investigation of the phase stability and the electronic properties for Gd-doped HfO{sub 2}  

SciTech Connect (OSTI)

Rare earth doping is an important approach to improve the desired properties of high-k gate dielectric oxides. We have carried out a comprehensive theoretical investigation on the phase stability, band gap, formation of oxygen vacancies, and dielectric properties for the Gd-doped HfO{sub 2}. Our calculated results indicate that the tetragonal phase is more stable than the monoclinic phase when the Gd doping concentration is greater than 15.5%, which is in a good agreement with the experimental observations. The dopant's geometric effect is mainly responsible for the phase stability. The Gd doping enlarges the band gap of the material. The dielectric constant for the Gd-doped HfO{sub 2} is in the range of 20–30 that is suitable for high-k dielectric applications. The neutral oxygen vacancy formation energy is 3.2?eV lower in the doped material than in pure HfO{sub 2}. We explain the experimental observation on the decrease of photoluminescence intensities in the Gd-doped HfO{sub 2} according to forming the dopant-oxygen vacancy complexes.

Wang, L. G. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); California Institute of Technology, Pasadena, California 91125 (United States); Xiong, Y.; Xiao, W.; Cheng, L.; Du, J.; Tu, H. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Walle, A. van de [Brown University, Providence, Rhode Island 02912 (United States); California Institute of Technology, Pasadena, California 91125 (United States)

2014-05-19T23:59:59.000Z

463

Crossover between weak localization and weak antilocalization in magnetically doped topological insulator  

E-Print Network [OSTI]

;Topological insulators (TI) are a new class of quantum materials with insulating bulk enclosedCrossover between weak localization and weak antilocalization in magnetically doped topological insulator Minhao Liu1,* , Jinsong Zhang1,* , Cui-Zu Chang1,2,* , Zuocheng Zhang1 , Xiao Feng2 , Kang Li2

Wang, Wei Hua

464

Tunable erbium-doped fiber ring laser using an intra-cavity filter  

E-Print Network [OSTI]

Linear tuning the frequency of an erbium-doped fiber ring laser using both a Fabry-Perot filter and an electro-optic tunable filter has been experimentally demonstrated. The rate of frequency change is determined by monitoring the fringes produced...

Fadel, Hicham Joseph

2004-11-15T23:59:59.000Z

465

Vortex pinning in electron-doped cuprate superconductor La2xCexCuO4  

E-Print Network [OSTI]

-beam epitaxy method. A structural XRD investigation revealed no doping-induced lattice strain. We use a two-coil on the underdoped side and decreases slowly on the overdoped side. The Labusch parameter j, i.e. the spring constant. The magnetic penetration depth was measured using a two-coil mutual inductance technique, as described in Refs

466

Materials Science and Engineering B88 (2002) 7378 Processing and properties of vanadium doped strontium niobate  

E-Print Network [OSTI]

strontium niobate Seana Seraji, Yun Wu, Steven Limmer, Tammy Chou, Caroyln Nguyen, Mike Forbess, G.Z. Cao October 2001 Abstract Strontium niobate was doped with vanadium and the resulting effects a relatively high vapor pressure [5]. Strontium niobate (Sr2Nb2O7) is a very promising candidate

Cao, Guozhong

467

Dielectric properties of MgO-doped compositionally graded multilayer barium strontium titanate films  

E-Print Network [OSTI]

Dielectric properties of MgO-doped compositionally graded multilayer barium strontium titanate shifters and filters operat- ing in the microwave regime.1­4 Ferroelectrics FEs such as barium strontium in monolithic BST films especially with low strontium content, although the addition of MgO causes a reduction

Alpay, S. Pamir

468

Manganese Doping of Magnetic Iron Oxide Nanoparticles: Tailoring Surface Reactivity for a Regenerable Heavy Metal Sorbent  

SciTech Connect (OSTI)

A method for tuning the analyte affinity of magnetic, inorganic nanostructured sorbents for heavy metal contaminants is described. The manganese-doped iron oxide nanoparticle sorbents have a remarkably high affinity compared to the precursor material. Sorbent affinity can be tuned toward an analyte of interest simply by adjustment of the dopant quantity. The results show that following the Mn doping process there is a large increase in affinity and capacity for heavy metals (i.e., Co, Ni, Zn, As, Ag, Cd, Hg, and Tl). Capacity measurements were carried out for the removal of cadmium from river water and showed significantly higher loading than the relevant commercial sorbents tested for comparison. The reduction in Cd concentration from 100 ppb spiked river water to 1 ppb (less than the EPA drinking water limit of 5 ppb for Cd) was achieved following treatment with the Mn-doped iron oxide nanoparticles. The Mn-doped iron oxide nanoparticles were able to load 1 ppm of Cd followed by complete stripping and recovery of the Cd with a mild acid wash. The Cd loading and stripping is shown to be consistent through multiple cycles with no loss of sorbent performance.

Warner, Cynthia L.; Chouyyok, Wilaiwan; Mackie, Katherine E.; Neiner, Doinita; Saraf, Laxmikant; Droubay, Timothy C.; Warner, Marvin G.; Addleman, Raymond S.

2012-02-28T23:59:59.000Z

469

Crystallography of Interfaces and Grain Size Distributions in Sr-Doped LaMnO3  

E-Print Network [OSTI]

Crystallography of Interfaces and Grain Size Distributions in Sr-Doped LaMnO3 Qinyuan Liu,§ Sudip systems are similar. I. Introduction HIGH-TEMPERATURE solid oxide fuel cells (SOFCs) offer highly efficient, clean, direct conversion of chemical to electrical energy.1 SOFC performance is dictated

Rohrer, Gregory S.

470

Improvement of high-frequency characteristics of Z-type hexaferrite by dysprosium doping  

SciTech Connect (OSTI)

Z-type hexaferrite has great potential applications as anti-EMI material for magnetic devices in the GHz region. In this work, Dy-doped Z-type hexaferrites with nominal stoichiometry of Ba{sub 3}Co{sub 2}Dy{sub x}Fe{sub 24-x}O{sub 41} (x 0.0, 0.05, 0.5, 1.0) were prepared by an improved solid-state reaction method. The effects of rare earth oxide (Dy{sub 2}O{sub 3}) addition on the phase composition, microstructure and electromagnetic properties of the ceramics were investigated. Structure and micromorphology characterizations indicate that certain content of Dy doping will cause the emergence of the second phase Dy{sub 3}Fe{sub 5}O{sub 12} at the grain boundaries of the majority phase Z-type hexaferrite, due to which the straightforward result is the grain refinement during the successive sintering process. Permeability spectra measurements show that the initial permeability reaches its maximum of 17 at 300 MHz with x = 0.5, while the cutoff frequency keeps above 800 MHz. The apparent specific anisotropy field H{sub K} of Dy-doped Z-type hexaferrites decreases with x increasing. The relationships among phase composition, grain size, permeability spectra, and anisotropy are theoretically investigated, and according to the analysis, Dy doping effects on its magnetic properties can be well explained and understood.

Mu Chunhong; Liu Yingli; Song Yuanqiang; Wang Liguo; Zhang Huaiwu [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2011-06-15T23:59:59.000Z

471

Self-doped block copolymer electrolytes for solid-state, rechargeable lithium batteries  

E-Print Network [OSTI]

Self-doped block copolymer electrolytes for solid-state, rechargeable lithium batteries Donald R. Introduction The ideal electrolyte material for a solid-state battery would have the ionic conductivity and cathode binder thin-®lm, solid-state, rechargeable lithium batteries of the type Li/ BCE/LiMnO2 have been

Sadoway, Donald Robert

472

Method for Improving Mg Doping During Group-III Nitride MOCVD  

DOE Patents [OSTI]

A method for improving Mg doping of Group III-N materials grown by MOCVD preventing condensation in the gas phase or on reactor surfaces of adducts of magnesocene and ammonia by suitably heating reactor surfaces between the location of mixing of the magnesocene and ammonia reactants and the Group III-nitride surface whereon growth is to occur.

Creighton, J. Randall (Albuquerque, NM); Wang, George T. (Albuquerque, NM)

2008-11-11T23:59:59.000Z

473

Study of the Microstructure of Doped Clathrate and Skutterudite Thermoelectric Materials  

E-Print Network [OSTI]

Study of the Microstructure of Doped Clathrate and Skutterudite Thermoelectric Materials Jihui Yang/problem: Clathrate and Skutterudite are known to be promising thermoelectric materials. The R&D groups at GM and ORNL of dopants. This is probably the key feature to enhancing the thermoelectric properties of this material

Pennycook, Steve

474

Radiation-induced gain degradation in lateral PNP BJTs with lightly and heavily doped emitters  

SciTech Connect (OSTI)

Ionizing radiation may cause failures in ICs due to gain degradation of individual devices. The base current of irradiated bipolar devices increases with total dose, while the collector current remains relatively constant. This results in a decrease in the current gain. Lateral PNP (LPNP) transistors typically exhibit more degradation than vertical PNP devices at the same total dose, and have been blamed as the cause of early IC failures at low dose rates. It is important to understand the differences in total-dose response between devices with heavily- and lightly-doped emitters in order to compare different technologies and evaluate the applicability of proposed low-dose-rate hardness-assurance methods. This paper addresses these differences by comparing two different LPNP devices from the same process: one with a heavily-doped emitter and one with a lightly-doped emitter. Experimental results demonstrate that the lightly-doped devices are more sensitive to ionizing radiation and simulations illustrate that increased recombination on the emitter side of the junction is responsible for the higher sensitivity.

Wu, A. [Univ. of Arizona, Tucson, AZ (United States); Schrimpf, R.D. [Vanderbilt Univ., Nashville, TN (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L. [VTC Inc., Bloomington, MN (United States)

1997-06-01T23:59:59.000Z

475

Dye-doped cholesteric-liquid-crystal room-temperature single-photon source*  

E-Print Network [OSTI]

Dye-doped cholesteric-liquid-crystal room-temperature single-photon source* SVETLANA G. LUKISHOVAy) increase the source efficiency, firstly, by aligning the dye molecules along the direction preferable output photons), secondly, by tuning the 1-D photonic-band-gap microcavity to the dye fluorescence band

Boyd, Robert W.

476

Light-induced Anchoring Evolution in Nematic Phase of Liquid Crystal Doped with Azo-dye  

E-Print Network [OSTI]

Light-induced Anchoring Evolution in Nematic Phase of Liquid Crystal Doped with Azo-dye D of Ukraine, Kyiv, Ukraine We report an experimental study of light-induced anchoring evolution of azo-dye=desorption of dye molecules on=from the boundary polymer aligning layer in the presence of light-induced bulk torque

Reznikov, Yuri

477

Self-orienting liquid crystal doped with polymer-azo-dye complex  

E-Print Network [OSTI]

Self-orienting liquid crystal doped with polymer-azo-dye complex Elena Ouskova,* Jaana Vapaavuori (LC) heterogeneous system that contains hydrogen-bonded polymer-azo-dye complexes at a low-orientation of liquid crystals due to light-induced desorption and adsorption of dye molecules on an aligning surface

Reznikov, Yuri

478

Light-induced rotation of dye-doped liquid crystal droplets  

E-Print Network [OSTI]

We investigate both theoretically and experimentally the rotational dynamics of micrometric droplets of dye-doped and pure liquid crystal induced by circularly and elliptically polarized laser light. The droplets are dispersed in water and trapped in the focus of the laser beam. Since the optical torque acting on the molecular director is known to be strongly enhanced in light-absorbing dye-doped materials, the question arises whether a similar enhancement takes place also for the overall optical torque acting on the whole droplets. We searched for such enhancement by measuring and comparing the rotation speed of dye-doped droplets induced by a laser beam having a wavelength either inside or outside the dye absorption band, and also comparing it with the rotation of pure liquid crystal droplets. No enhancement was found, confirming that photoinduced dye effects are only associated with an internal exchange of angular momentum between orientational and translational degrees of freedom of matter. Our result provides also the first direct experimental proof of the existence of a photoinduced stress tensor in the illuminated dye-doped liquid crystal. Finally, peculiar photoinduced dynamical effects are predicted to occur in droplets in which the molecular director is not rigidly locked to the flow, but so far they could not be observed.

C. Manzo; D. Paparo; L. Marrucci; I. Janossy

2007-12-05T23:59:59.000Z

479

Scintillators based on aromatic dye molecules doped in a sol-gel and N. Solovieva  

E-Print Network [OSTI]

Scintillators based on aromatic dye molecules doped in a sol-gel glass host M. Nikla and N. Fast energy transfer from the glass host to the dye luminescent centers was found. While the overall. In a trial to combine organic dye-based emission centers with an inorganic host, lead

Strathclyde, University of

480

Nitrogen-doped graphene and its electrochemical applications Yuyan Shao,a  

E-Print Network [OSTI]

Nitrogen-doped graphene and its electrochemical applications Yuyan Shao,a Sheng Zhang,a Mark H the widely-used expensive Pt for oxygen reduction. The excellent electrochemical performance of N-graphene is promising for applications in electrochemical energy devices (fuel cells, metal­air batteries

Aksay, Ilhan A.

Note: This page contains sample records for the topic "doping dual-gated bilayer" 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.


481

Negative differential resistance devices by using N-doped graphene nanoribbons  

SciTech Connect (OSTI)

Recently, extensive efforts have been devoted to the investigations of negative differential resistance (NDR) behavior in graphene. Here, by performing fully self-consistent density functional theory calculations combined with non-equilibrium Green's function technique, we investigate the transport properties of three molecules from conjugated molecule, one-dimension alkane chain, and single molecule magnet, which are sandwiched between two N-doped zigzag and armchair graphene nanoribbons (GNRs). We observe robust NDR effect in all examined molecular junctions including benzene, alkane, and planar four-coordinated Fe complex. Through the analyses of the calculated electronic structures and the bias-dependent transmission coefficients, we find that the narrow density of states of N-doped GNRs and the bias-dependent effective coupling between the discrete frontier molecular orbitals and the subbands of N-doped GNRs are responsible for the observed NDR phenomenon. These theoretical findings imply that N-doped GNRs hold great potential for building NDR devices based on various molecules.

Huang, Jing, E-mail: jhuang@ustc.edu.cn, E-mail: liqun@ustc.edu.cn [School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, Anhui 230601 (China) [School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, Anhui 230601 (China); Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang, Weiyi; Li, Qunxiang, E-mail: jhuang@ustc.edu.cn, E-mail: liqun@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yang, Jinlong [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-04-28T23:59:59.000Z

482

The Influence of Doping Levels and Surface Termination on the Electrochemistry of Polycrystalline Diamond  

E-Print Network [OSTI]

of Polycrystalline Diamond Matthew N. Latto, Gustavo Pastor-Moreno, D. Jason Riley* School of Chemistry, University on the redox chemistry of Fe(CN)3À=4À 6 at CVD polycrystalline diamond electrodes is considered diamond metallic electrochemical behavior is always observed, even at boron doping densities as low as 7 Â

Bristol, University of

483

Characterization of B-doped polycrystalline diamond films using thermally stimulated luminescence  

E-Print Network [OSTI]

1 Characterization of B-doped polycrystalline diamond films using thermally stimulated luminescence, boron level in polycrystalline diamond films was identified by TL by an intense glow peak at 226 K polycrystalline diamond films grown by Chemical Vapor Deposition (CVD) have a wide array of potential applications

Paris-Sud XI, Université de

484

Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites  

DOE Patents [OSTI]

A fiber-reinforced silicon--silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon--silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

Corman, Gregory Scot (Ballston Lake, NY); Luthra, Krishan Lal (Schenectady, NY)

1999-01-01T23:59:59.000Z

485

Method of enhanced lithiation of doped silicon carbide via high temperature annealing in an inert atmosphere  

SciTech Connect (OSTI)

A method for enhancing the lithium-ion capacity of a doped silicon carbide is disclosed. The method utilizes heat treating the silicon carbide in an inert atmosphere. Also disclosed are anodes for lithium-ion batteries prepared by the method.

Hersam, Mark C.; Lipson, Albert L.; Bandyopadhyay, Sudeshna; Karmel, Hunter J; Bedzyk, Michael J

2014-05-27T23:59:59.000Z

486

Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites  

DOE Patents [OSTI]

A fiber-reinforced silicon-silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon-silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

Corman, Gregory Scot (Ballston Lake, NY); Luthra, Krishan Lal (Schenectady, NY)

2002-01-01T23:59:59.000Z

487

Quenched by ice: Transient grating measurements of vibronic dynamics in bromine-doped ice  

E-Print Network [OSTI]

Quenched by ice: Transient grating measurements of vibronic dynamics in bromine-doped ice I. U April 2006; published online 25 May 2006 In both water and in ice, the absorption spectra of bromine of the trapped molecule in its electronic B 3 0u state in ice. Independent of the initial excitation energy

Apkarian, V. Ara

488

Porous Boron-Doped Diamond/Carbon Nanotube Electrodes H. Zanin,*,  

E-Print Network [OSTI]

with BDD (large potential window, chemical inertness, low background levels), but also they have application in electronics and sensors, such B-doped diamond (BDD) films are increasingly being used and a very low background current, in addition to chemical and physical stability.7 Planar BDD electrodes

Bristol, University of

489

Adsorption structure and doping effect of azidotrimethyltin on graphene , S.N. Yang b  

E-Print Network [OSTI]

Adsorption structure and doping effect of azidotrimethyltin on graphene J. Choi a , S.N. Yang b , K Graphene Chemical functionalization Synchrotron Photoemission spectroscopy a b s t r a c t The adsorption demonstrate the variation of characteristic of graphene induced by the chemical functionalized molecule as we

Kim, Sehun

490

Thermopower, electrical and Hall conductivity of undoped and doped iron disilicide single crystals  

SciTech Connect (OSTI)

The electrical transport properties of {beta}-FeSi{sub 2} single crystals have been investigated in dependence on the purity of the source material and on doping with 3d transition metals. The transport properties included are electrical conductivity, Hall conductivity and thermopower mainly in the temperature range from 4K to 300K. The single crystals have been prepared by chemical transport reaction in a closed system with iodine as transport agent. In undoped single crystals prepared with 5N Fe both electrical conductivity and thermopower depend on the composition within the homogeneity range of {beta}-FeSi{sub 2} which is explained by different intrinsic defects at the Si-rich and Fe-rich phase boundaries. In both undoped and doped single crystals impurity band conduction is observed at low temperatures but above 100K extrinsic behavior determined by shallow impurity states. The thermopower shows between 100K and 200K a significant phonon drag contribution which depends on intrinsic defects and additional doping. The Hall resistivity is considered mainly with respect to an anomalous contribution found in p-type and n-type single crystals and thin films. In addition doped single crystals show at temperatures below about 130K an hysteresis of the Hall voltage. These results make former mobility data uncertain. Comparison will be made between the transport properties of single crystals and polycrystalline material.

Heinrich, A.; Behr, G.; Griessmann, H.; Teichert, S.; Lange, H.

1997-07-01T23:59:59.000Z

491

additives doped-uo2 pellets: Topics by E-print Network  

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

additives doped-uo2 pellets First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Journal of Nuclear...

492

Impact of degenerate n-doping on the optical absorption edge in transparent conducting cadmium oxide  

E-Print Network [OSTI]

n-type or can be heavily doped. Transparent conductive cadmium oxide (CdO) thin films, for instance devices or modern solar cells, material performance is critically important. A combination of high in the conduction bands of CdO can increase the conductivity up to values desired for technological applications

Schleife, André

493

Porous Doped Silicon Nanowires for Lithium Ion Battery Anode with Long Cycle Life  

E-Print Network [OSTI]

in energy storage has stimulated significant interest in lithium ion battery research. The lithium ion battery is one of the most promising systems which is efficient in delivering energy, light in weightPorous Doped Silicon Nanowires for Lithium Ion Battery Anode with Long Cycle Life Mingyuan Ge

Zhou, Chongwu

494

Tuning nucleation density of metal island with charge doping of graphene Wenmei Ming and Feng Liua)  

E-Print Network [OSTI]

increase both Fe-adatom diffusion barrier and Fe inter- adatom repulsion energy occurring at intermediate separation, whereas electron-doping can decrease Fe-adatom diffusion barrier but only slightly modify inter­10 which are strongly related to the bonding involving orbital hybridization and charge transfer between

Simons, Jack

495

Plasma-assisted nitrogen doping of graphene-encapsulated Pt nanocrystals as efficient fuel cell  

E-Print Network [OSTI]

Plasma-assisted nitrogen doping of graphene- encapsulated Pt nanocrystals as efficient fuel cell, their ability to act as a relatively good fuel cell catalyst was confirmed. Furthermore, to further improve with hydrogen and oxygen intermediates to form the nal products,10 explaining their broad use in fuel cell

Tan, Weihong

496

Fermi Level Control of Point Defects During Growth of Mg-Doped GaN  

E-Print Network [OSTI]

, and photodetectors have been developed, but the optical transitions in GaN:Mg are still not well under- stood.2 Mg.1007/s11664-012-2342-9 Ã? 2012 TMS #12;irradiation during growth affected the material, but the nature demonstrate point defect control in Mg-doped GaN, by UV irradiation during growth. First, details

Nabben, Reinhard

497

Chemical Synthesis of Pure and Gd-doped CaZrO3 Powders  

E-Print Network [OSTI]

chemical synthesis techniques: (i) self-propagating combustion synthesis, and (ii) precipitation potential use as a high-temperature thermistor material.8 The electrical response of calcium zirconate (preChemical Synthesis of Pure and Gd-doped CaZrO3 Powders I. Erkin Gonenli a and A. CuÃ? neyt Tas b

Tas, A. Cuneyt

498

Reverse saturation current density imaging of highly doped regions in silicon: A photoluminescence approach  

E-Print Network [OSTI]

´ a , Rolf Brendel a,b a Institute for Solar Energy Research Hamelin (ISFH), Am Ohrberg 1, 31860 Emmerthal Doping (LTD) as well as standard tube furnace phosphorus diffusion. We find a considerably smaller J0 for process optimization. & 2012 Elsevier B.V. All rights reserved. 1. Introduction In silicon solar cells

499

Infrared Charge-Modulation Spectroscopy of Defects in Phosphorus Doped Amorphous Silicon  

E-Print Network [OSTI]

Infrared Charge-Modulation Spectroscopy of Defects in Phosphorus Doped Amorphous Silicon KAI ZHU Solar, Toano, VA 23168 USA ABSTRACT We present infrared charge-modulation absorption spectra have been developing an infrared modulation spectroscopy technique that probes the optical spectra

Schiff, Eric A.

500

Infrared and photoluminescence spectroscopy of p-doped self-assembled Ge dots on Si  

E-Print Network [OSTI]

Infrared and photoluminescence spectroscopy of p-doped self-assembled Ge dots on Si L. P Received 14 June 1999; accepted for publication 17 August 1999 We report infrared photocurrent PC-8 Quantum well infrared photodetector QWIP technol- ogy has matured rapidly in the last several years.1

Rokhinson, Leonid