National Library of Energy BETA

Sample records for zn cd hg

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

    SciTech Connect (OSTI)

    Schwarz, Michael; Wendorff, Marco; Roehr, Caroline

    2012-12-15

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

  2. Blue electroluminescence from ZnO based heterojunction diodes with CdZnO active layers

    E-Print Network [OSTI]

    Yang, Zheng

    with CdO.3­5 This makes ZnO based light sources emitting light from ultraviolet region to green band were used as p-type layer. Our group has demonstrated stable Sb doped p-type ZnO grown on Si substrate8 and several ZnO hetero- and homojunction devices using Sb doped ZnO as p-type layer.9­11 Dominant UV emissions

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

    SciTech Connect (OSTI)

    Hernández-Calderón, I.; Salcedo-Reyes, J. C.

    2014-05-15

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

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

    SciTech Connect (OSTI)

    Williams, B. L.; Phillips, L.; Major, J. D.; Durose, K.; Taylor, A. A.; Mendis, B. G.; Bowen, L.

    2014-02-03

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

  5. Experimental study of 113Cd beta decay using CdZnTe detectors

    E-Print Network [OSTI]

    C. Goessling; M. Junker; H. Kiel; D. Muenstermann; S. Oehl; K. Zuber

    2005-08-12

    A search for the 4-fold forbidden beta decay of \\iso{Cd}{113} has been performed with CdZnTe semiconductors. With 0.86 kg $\\cdot$ days of statistics a half-life for the decay of $T_{1/2} = (8.2 \\pm 0.2 (stat.) ^{+0.2}_{-1.0} (sys.)) \\cdot 10^{15}$yrs has been obtained. This is in good agreement with published values. A comparison of the spectral shape with the one given on the Table of Isotopes Web-page shows a severe deviation.

  6. Purification of CdZnTe by Electromigration

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

    Kim, K.; Kim, Sangsu; Hong, Jinki; Lee, Jinseo; Hong, Taekwon; Bolotnikov, A. E.; Camarda, G. S.; James, R. B.

    2015-04-14

    Electro-migration of ionized/electrically active impurities in CdZnTe (CZT) was successfully demonstrated at elevated temperature with an electric field of 20 V/mm. Copper, which exists in positively charged states, electro-migrated at a speed of 15 lm/h in an electric field of 20 V/mm. A notable variation in impurity concentration along the growth direction with the segregation tendency of the impurities was observed in an electro-migrated CZT boule. Notably, both Ga and Fe, which exist in positively charged states, exhibited the opposite distribution to that of their segregation tendency in Cd(Zn)Te. Furthermore, a CZT detector fabricated from the middle portion of themore »electromigrated CZT boule showed an improved mobility-lifetime product of 0.91 10-2 cm2 /V, compared to that of 1.4 10-3 cm2 /V, observed in an as-grown (non-electro-migrated) CZT detector. The optimum radiation detector material would have minimum concentration of deep traps required for compensation.« less

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

    E-Print Network [OSTI]

    Osswald, Sebastian

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

  8. RETENTION OF Cd, Cu, Pb AND Zn BY WOOD ASH, LIME AND FUME DUST

    E-Print Network [OSTI]

    Ma, Lena

    RETENTION OF Cd, Cu, Pb AND Zn BY WOOD ASH, LIME AND FUME DUST TAIT CHIRENJE1 , LENA Q. MA2 and ecosystem health. This study investigated the effectiveness of wood ash in immobilizing the heavy metals Pb, Cd, Cu and Zn from aqueous solutions. The effects of initial metal concentrations, solution pH, ash

  9. Development of ZnNiCd coatings by pulse electrodeposition process Prabhu Ganesan, Swaminatha P. Kumaraguru, Branko N. Popov

    E-Print Network [OSTI]

    Popov, Branko N.

    Development of Zn­Ni­Cd coatings by pulse electrodeposition process Prabhu Ganesan, Swaminatha P indicated that Zn­Ni­Cd alloys exhibit superior barrier properties when compared to Cd or Zn­Ni coatings of corrosion resistant coating in aerospace, electrical, and fastener industries due to its excel- lent

  10. CdSe self-assembled quantum dots with ZnCdMgSe barriers emitting throughout the visible spectrum

    SciTech Connect (OSTI)

    Perez-Paz, M. Noemi; Zhou Xuecong; Munoz, Martin; Lu Hong; Sohel, Mohammad; Tamargo, Maria C.; Jean-Mary, Fleumingue; Akins, Daniel L.

    2004-12-27

    Self-assembled quantum dots of CdSe with ZnCdMgSe barriers have been grown by molecular beam epitaxy on InP substrates. The optical and microstructural properties were investigated using photoluminescence (PL) and atomic force microscopy (AFM) measurements. Control and reproducibility of the quantum dot (QD) size leading to light emission throughout the entire visible spectrum range has been obtained by varying the CdSe deposition time. Longer CdSe deposition times result in a redshift of the PL peaks as a consequence of an increase of QD size. AFM studies demonstrate the presence of QDs in uncapped structures. A comparison of this QD system with CdSe/ZnSe shows that not only the strain but also the chemical properties of the system play an important role in QD formation.

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

    E-Print Network [OSTI]

    Coe-Sullivan, Seth (Seth Alexander)

    2002-01-01

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

  12. Simulation, Modeling, and Crystal Growth of Cd0.9Zn0.1Te for...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Simulation, Modeling, and Crystal Growth of Cd0.9Zn0.1Te for Nuclear Spectrometers Citation Details In-Document Search Title: Simulation, Modeling, and Crystal...

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

    E-Print Network [OSTI]

    Chin, B.L.

    2013-01-01

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

  14. Defect study in molecular beam epitaxy-grown HgCdTe films with activated and unactivated arsenic

    SciTech Connect (OSTI)

    Izhnin, I. I.; Dvoretsky, S. A.; Mikhailov, N. N.; Varavin, V. S.; Mynbaev, K. D.; Fitsych, O. I.; Pociask-Bialy, M.; Sheregii, E.; Voitsekhovskii, A. V.

    2014-04-28

    A defect study was performed on molecular beam epitaxy-grown HgCdTe films in situ doped with arsenic. Doping was performed from either effusion cell or cracker cell, and studied were both as-grown samples and samples subjected to arsenic activation annealing. Electrical properties of the films were investigated with the use of ion milling as a means of “stirring” defects in the material. As a result of the study, it was confirmed that the most efficient incorporation of electrically active arsenic occurs at the cracking zone temperature of 700?°C. Interaction between arsenic and tellurium during the growth was observed and is discussed in the paper.

  15. Highly efficient nonradiative energy transfer using charged CdSe/ZnS nanocrystals for light-harvesting in solution

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    % in solution. CdTe and CdSe/ZnS dots of different sizes have further been studied for energy trans- fer in filmHighly efficient nonradiative energy transfer using charged CdSe/ZnS nanocrystals for light-harvesting in solution Evren Mutlugün,a Sedat Nizamolu, and Hilmi Volkan Demirb Department of Physics; Department

  16. Luminescence of CdSe/ZnS quantum dots infiltrated into an opal matrix

    SciTech Connect (OSTI)

    Gruzintsev, A. N. Emelchenko, G. A.; Masalov, V. M.; Yakimov, E. E.; Barthou, C.; Maitre, A.

    2009-02-15

    The effect of the photonic band gap in the photonic crystal, the synthesized SiO{sub 2} opal with embedded CdSe/ZnS quantum dots, on its luminescence in the visible spectral region is studied. It is shown that the position of the photonic band gap in the luminescence and reflectance spectra for the infiltrated opal depends on the diameter of the constituent nanospheres and on the angle of recording the signal. The optimal conditions for embedding the CdSe/ZnS quantum dots from the solution into the opal matrix are determined. It is found that, for the opal-CdSe/ZnS nanocomposites, the emission intensity decreases and the luminescence decay time increases in the spatial directions, in which the spectral positions of the photonic band gap and the luminescence peak of the quantum dots coincide.

  17. Effects of Cu Diffusion from ZnTe:Cu/Ti Contacts on Carrier Lifetime of CdS/CdTe Thin Film Solar Cells: Preprint

    SciTech Connect (OSTI)

    Gessert, T. A.; Metzger, W. K.; Asher, S. E.; Young, M. R.; Johnston, S.; Dhere, R. G.; Duda, A.

    2008-05-01

    We study the performance of CdS/CdTe thin film PV devices processed with a ZnTe:Cu/Ti contact to investigate how carrier lifetime in the CdTe layer is affected by Cu diffusion from the contact.

  18. Correlation Between Bands Structure and Magneto-Transport Properties in n-type HgTe/CdTe Superlattice with Relatively Thin CdTe Barrier

    SciTech Connect (OSTI)

    Braigue, M.; Nafidi, A.; Chaib, H.; Tirbiyine, A.; Hemine, J.; Idbaha, A.; Boulkassim, A.; El Gouti, T.; Massaq, M. [Laboratory of Condensed Matter Physics and Nanomaterials for Renewable Energy, Department of Physics, Faculty of Sciences, BP 8106 Hay Dakhla (Morocco); University Ibn Zohr, 80000 Agadir (Morocco); Talwar, Devki N. [Physics Department, Indiana University of Pennsylvania, 975 Oakland Avenue, Indiana, PA 15705 (United States); SrinivasaVinod, M. [Mechanical Engineering Department, RV College of Engineering, Bangalore - 560 059 (India)

    2011-12-26

    Theoretical calculations of the electronic properties of n-type HgTe/CdTe superlattices (SLs) in the envelope function formalism have provided a reasonable agreement with the experimental data on the magneto-transport behavior. Numerical results of the band energies E(d{sub 2}), E(k{sub z}) and E(k{sub p}) in the direction of growth and in plane of the SLs predict that the system retains semiconductor characteristics for d{sub 1}/d{sub 2} = 2.69 and d{sub 2}<10 nm. For d{sub 2} = 3.2 nm the calculated effective band gap (E{sub g}({Gamma},4.2 K) = 48 meV) suggests that the material sample is a two-dimensional modulated nanostructure and a potential candidate to be used for the far infrared detection applications.

  19. Characterization of a large CdZnTe coplanar quad-grid semiconductor detector

    E-Print Network [OSTI]

    The COBRA collaboration; Joachim Ebert; Claus Gößling; Daniel Gehre; Caren Hagner; Nadine Heidrich; Rainer Klingenberg; Kevin Kröninger; Christian Nitsch; Christian Oldorf; Thomas Quante; Silke Rajek; Henning Rebber; Katja Rohatsch; Jan Tebrügge; Robert Temminghoff; Robert Theinert; Jan Timm; Björn Wonsak; Stefan Zatschler; Kai Zuber

    2015-09-08

    The COBRA collaboration aims to search for neutrinoless double beta-decay of $^{116}$Cd. A demonstrator setup with 64 CdZnTe semiconductor detectors, each with a volume of 1cm$^3$, is currently being operated at the LNGS underground laboratory in Italy. This paper reports on the characterization of a large (2 $\\times$ 2 $\\times$ 1.5)cm$^3$ CdZnTe detector with a new coplanar-grid design for applications in $\\gamma$-ray spectroscopy and low-background operation. Several studies of electric properties as well as of the spectrometric performance, like energy response and resolution, are conducted. Furthermore, measurements including investigating the operational stability and a possibility to identify multiple-scattered photons are presented.

  20. sup 3 P Hg, Cd, and Zn photosensitized chemistry of vinyl halides in krypton matrix

    SciTech Connect (OSTI)

    Cartland, H.E.; Pimentel, G.C. )

    1990-01-25

    The reaction of group IIB metals in the {sup 3}P state with vinyl fluoride, chloride, and bromide is studied in krypton matrix. The primary process in all cases is hydrogen halide elimination to form a hydrogen halide/acetylene hydrogen-bonded complex. Insertion of metal atoms into C-Cl and C-Br bonds, but not into C-H and C-F bonds, is also observed. The insertion photochemistry can be explained by a mechanism which requires that the process occur on a triplet surface with the vinyl halide in the planar ground-state conformation.

  1. Cyan electroluminescence from n-ZnO/i-CdZnO/p-Si heterojunction diodes Lin Li, Zheng Yang and Jianlin Liu

    E-Print Network [OSTI]

    Yang, Zheng

    .8 eV by alloying with CdO [3-6]. This property makes ZnO based light sources emitting light from for 5 min under vacuum, then a 350 nm Ga-doped ZnO layer was deposited at 500 °C as n-type layer. Room used for contacts of both Ga-doped ZnO and p-type Si. The contacts were subjected to rapid thermal

  2. The effects of deep level traps on the electrical properties of semi-insulating CdZnTe

    SciTech Connect (OSTI)

    Zha, Gangqiang; Yang, Jian; Xu, Lingyan; Feng, Tao; Wang, Ning; Jie, Wanqi

    2014-01-28

    Deep level traps have considerable effects on the electrical properties and radiation detection performance of high resistivity CdZnTe. A deep-trap model for high resistivity CdZnTe was proposed in this paper. The high resistivity mechanism and the electrical properties were analyzed based on this model. High resistivity CdZnTe with high trap ionization energy E{sub t} can withstand high bias voltages. The leakage current is dependent on both the deep traps and the shallow impurities. The performance of a CdZnTe radiation detector will deteriorate at low temperatures, and the way in which sub-bandgap light excitation could improve the low temperature performance can be explained using the deep trap model.

  3. Weak antilocalization effect in LPE-grown p-Hg0.8Cd0.2Te thin film and the evidence of Te-precipitation

    E-Print Network [OSTI]

    R. Yang; L. M. Wei; G. L. Yu

    2010-06-07

    The weak antilocalization effect is observed in a p-type Hg0.8Cd0.2Te thin film with thickness ~10 micrometers. Based on the analysis of composition, carrier species and excellent fitting of data with a model concerning weak antilocalization effect in Te crystal, the most plausible explanation is that the observed weak antilocalization effect is caused by Te-precipitation.

  4. New acceptor centers of the background impurities in p-CdZnTe

    SciTech Connect (OSTI)

    Plyatsko, S. V. Rashkovetskyi, L. V.

    2013-07-15

    Low-temperature photoluminescence data are used to study the redistribution of the background impurities and host components of p-CdZnTe single crystals with a resistivity of 1-50 {Omega} cm upon their interaction with infrared laser radiation. The effect of widening of the band gap and the formation of new acceptor centers in response to laser-stimulated changes in the system of intrinsic defects are established. The activation energy of the new acceptor centers is determined.

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

    SciTech Connect (OSTI)

    Valverde-Chávez, D. A.; Sutara, F.; Hernández-Calderón, I.

    2014-05-15

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

  6. Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers

    SciTech Connect (OSTI)

    Shen, A.; Lu, H.; Charles, W.; Yokomizo, I.; Tamargo, M. C.; Franz, K. J.; Gmachl, C.; Zhang, S. K.; Zhou, X.; Alfano, R. R.; Liu, H. C.

    2007-02-12

    The authors report the observation of intersubband absorption in multilayers of CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dots. The samples were grown by molecular beam epitaxy on InP substrates. For samples with the CdSe dot layers doped with Cl and with the deposited CdSe equivalent layer thickness between 5.2 and 6.9 ML, peak absorption between 2.5 and 3.5 {mu}m was observed. These materials are promising for intersubband devices operating in the mid- and near-infrared ranges.

  7. Impact of annealing on the chemical structure and morphology of the thin-film CdTe/ZnO interface

    SciTech Connect (OSTI)

    Horsley, K. Hanks, D. A.; Weir, M. G.; Beal, R. J.; Wilks, R. G.; Blum, M.; Häming, M.; Hofmann, T.; Weinhardt, L.; and others

    2014-07-14

    To enable an understanding and optimization of the optoelectronic behavior of CdTe-ZnO nanocomposites, the morphological and chemical properties of annealed CdTe/ZnO interface structures were studied. For that purpose, CdTe layers of varying thickness (4–24?nm) were sputter-deposited on 100?nm-thick ZnO films on surface-oxidized Si(100) substrates. The morphological and chemical effects of annealing at 525?°C were investigated using X-ray Photoelectron Spectroscopy (XPS), X-ray-excited Auger electron spectroscopy, energy dispersive X-ray spectroscopy, scanning electron microscopy, and atomic force microscopy. We find a decrease of the Cd and Te surface concentration after annealing, parallel to an increase in Zn and O signals. While the as-deposited film surfaces show small grains (100?nm diameter) of CdTe on the ZnO surface, annealing induces a significant growth of these grains and separation into islands (with diameters as large as 1??m). The compositional change at the surface is more pronounced for Cd than for Te, as evidenced using component peak fitting of the Cd and Te 3d XPS peaks. The modified Auger parameters of Cd and Te are also calculated to further elucidate the local chemical environment before and after annealing. Together, these results suggest the formation of tellurium and cadmium oxide species at the CdTe/ZnO interface upon annealing, which can create a barrier for charge carrier transport, and might allow for a deliberate modification of interface properties with suitably chosen thermal treatment parameters.

  8. Effects of sub-bandgap illumination on electrical properties and detector performances of CdZnTe:In

    SciTech Connect (OSTI)

    Xu, Lingyan; Jie, Wanqi, E-mail: jwq@nwpu.edu.cn; Zha, Gangqiang, E-mail: zha-gq@hotmail.com; Feng, Tao; Wang, Ning; Xi, Shouzhi; Fu, Xu; Zhang, Wenlong; Xu, Yadong; Wang, Tao [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072 (China)

    2014-06-09

    The effects of sub-bandgap illumination on electrical properties of CdZnTe:In crystals and spectroscopic performances of the fabricated detectors were discussed. The excitation process of charge carriers through thermal and optical transitions at the deep trap could be described by the modified Shockley-Read-Hall model. The ionization probability of the deep donor shows an increase under illumination, which should be responsible for the variation of electrical properties within CdZnTe bulk materials with infrared (IR) irradiation. By applying Ohm's law, diffusion model and interfacial layer-thermionic-diffusion theory, we obtain the decrease of bulk resistivity and the increase of space charge density in the illuminated crystals. Moreover, the illumination induced ionization will further contribute to improving carrier transport property and charge collection efficiency. Consequently, the application of IR irradiation in the standard working environment is of great significance to improve the spectroscopic characteristics of CdZnTe radiation detectors.

  9. Reduction of surface leakage current by surface passivation of CdZn Te and other materials using hyperthermal oxygen atoms

    DOE Patents [OSTI]

    Hoffbauer, Mark A. (Los Alamos, NM); Prettyman, Thomas H. (Los Alamos, NM)

    2001-01-01

    Reduction of surface leakage current by surface passivation of Cd.sub.1-x Zn.sub.x Te and other materials using hyperthermal oxygen atoms. Surface effects are important in the performance of CdZnTe room-temperature radiation detectors used as spectrometers since the dark current is often dominated by surface leakage. A process using high-kinetic-energy, neutral oxygen atoms (.about.3 eV) to treat the surface of CdZnTe detectors at or near ambient temperatures is described. Improvements in detector performance include significantly reduced leakage current which results in lower detector noise and greater energy resolution for radiation measurements of gamma- and X-rays, thereby increasing the accuracy and sensitivity of measurements of radionuclides having complex gamma-ray spectra, including special nuclear materials.

  10. HAND-HELD GAMMA-RAY SPECTROMETER BASED ON HIGH-EFFICIENCY FRISCH-RING CdZnTe DETECTORS.

    SciTech Connect (OSTI)

    CUI,Y.

    2007-05-01

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution, el% FWHM at 662 keV, and good efficiency for detecting gamma rays. This technique facilitates the application of CdZnTe materials for high efficiency gamma-ray detection. A hand-held gamma-ray spectrometer based on Frisch-ring detectors is being designed at Brookhaven National Laboratory. It employs an 8x8 CdZnTe detector array to achieve a high volume of 19.2 cm3, so that detection efficiency is significantly improved. By using the front-end ASICs developed at BNL, this spectrometer has a small profile and high energy resolution. The spectrometer includes signal processing circuit, digitization and storage circuit, high-voltage module, and USB interface. In this paper, we introduce the details of the system structure and report our test results with it.

  11. Structure and red shift of optical band gap in CdO–ZnO nanocomposite synthesized by the sol gel method

    SciTech Connect (OSTI)

    Mosquera, Edgar, E-mail: edemova@ing.uchile.cl [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile); Pozo, Ignacio del, E-mail: ignacio.dpf@gmail.com [Facultad de Ciencias Naturales, Matemáticas y del Medio Ambiente, Universidad Tecnológica Metropolitana, Av. José Pedro Alessandri 1242, Santiago (Chile); Morel, Mauricio, E-mail: mmorel@ing.uchile.cl [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile)

    2013-10-15

    The structure and the optical band gap of CdO–ZnO nanocomposites were studied. Characterization using X-ray diffraction (XRD), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS) analysis confirms that CdO phase is present in the nanocomposites. TEM analysis confirms the formation of spheroidal nanoparticles and nanorods. The particle size was calculated from Debey–Sherrer?s formula and corroborated by TEM images. FTIR spectroscopy shows residual organic materials (aromatic/Olefinic carbon) from nanocomposites surface. CdO content was modified in the nanocomposites in function of polyvinylalcohol (PVA) added. The optical band gap is found to be red shift from 3.21 eV to 3.11 eV with the increase of CdO content. Photoluminescence (PL) measurements reveal the existence of defects in the synthesized CdO–ZnO nanocomposites. - Graphical abstract: Optical properties of ZnO, CdO and ZnO/CdO nanoparticles. Display Omitted - Highlights: • TEM analysis confirms the presence of spherical nanoparticles and nanorods. • The CdO phase is present in the nanocomposites. • The band gap of the CdO–ZnO nanocomposites is slightly red shift with CdO content. • PL emission of CdO–ZnO nanocomposite are associated to structural defects.

  12. Measuring charge trap occupation and energy level in CdSe/ZnS quantum dots using a scanning tunneling microscope

    E-Print Network [OSTI]

    Hummon, M. R.

    We use a scanning tunneling microscope to probe single-electron charging phenomena in individual CdSe/ZnS (core/shell) quantum dots (QDs) at room temperature. The QDs are deposited on top of a bare Au thin film and form a ...

  13. Linking heavy metal bioavailability (Cd, Cu, Zn and Pb) in Scots pine needles to soil properties in reclaimed mine areas

    E-Print Network [OSTI]

    Silver, Whendee

    Linking heavy metal bioavailability (Cd, Cu, Zn and Pb) in Scots pine needles to soil properties elements bioavailability and biological (dehydrogenase activity) and physico-chemical properties of mine areas affected by hard coal, sand, lignite and sulphur mining, there is no risk of trace element

  14. Photoluminescence Enhancement in CdSe/ZnS–DNA linked–Au Nanoparticle Heterodimers Probed by Single Molecule Spectroscopy

    SciTech Connect (OSTI)

    Cotlet, M.; Maye, M.M.; Gang, O.

    2010-07-26

    Photoluminescence enhancement of up to 20 fold is demonstrated at the single molecule level for heterodimers composed of a core/shell CdSe/ZnS semiconductive quantum dot and a gold nanoparticle of 60 nm size separated by a 32 nm-long dsDNA linker when employing optical excitation at wavelengths near the surface plasmon resonance of the gold nanoparticle.

  15. Biologically programmed synthesis of core-shell CdSe/ZnS nanocrystalsw Shailendra Singh,ab

    E-Print Network [OSTI]

    Chen, Wilfred

    not only directs the nucleation of inorganic materials, but also controls the crystal structure and sizeBiologically programmed synthesis of core-shell CdSe/ZnS nanocrystalsw Shailendra Singh report of core-shell semiconductor nanocrystal synthesis using a peptide template. Type II

  16. InAs(ZnCdS) Quantum Dots Optimized for Biological Imaging in the Near-Infrared

    E-Print Network [OSTI]

    Allen, Peter M.

    We present the synthesis of InAs quantum dots (QDs) with a ZnCdS shell with bright and stable emission in the near-infrared (NIR, 700?900 nm) region for biological imaging applications. We demonstrate how NIR QDs can image ...

  17. Fermi level stabilization and band edge energies in Cd{sub x}Zn{sub 1?x}O alloys

    SciTech Connect (OSTI)

    Detert, Douglas M.; Tom, Kyle B.; Dubon, Oscar D. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Battaglia, Corsin; Javey, Ali [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Denlinger, Jonathan D. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lim, Sunnie H. N. [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Anders, André [Accelerator and Fusion Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Yu, Kin M.; Walukiewicz, Wladek [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-06-21

    We have measured the band edge energies of Cd{sub x}Zn{sub 1?x}O thin films as a function of composition by three independent techniques: we determine the Fermi level stabilization energy by pinning the Fermi level with ion irradiation, measure the binding energy of valence band states and core levels by X-ray photoelectron spectroscopy, and probe shifts in the conduction band and valence band density of states using soft X-ray absorption and emission spectroscopy, respectively. The three techniques find consensus in explaining the origin of compositional trends in the optical-bandgap narrowing upon Cd incorporation in wurtzite ZnO and widening upon Zn incorporation in rocksalt CdO. The conduction band minimum is found to be stationary for both wurtzite and rocksalt alloys, and a significant upward rise of the valence band maximum accounts for the majority of these observed bandgap changes. Given these band alignments, alloy disorder scattering is found to play a negligible role in decreasing the electron mobility for all alloys. These band alignment details, combined with the unique optical and electrical properties of the two phase regimes, make CdZnO alloys attractive candidates for photoelectrochemical water splitting applications.

  18. Photo-instability of CdSe/ZnS quantum dots in poly(methylmethacrylate) film

    SciTech Connect (OSTI)

    Zhang, Hongyi; Liu, Yu; Ye, Xiaoling; Chen, Yonghai

    2013-12-28

    The photo-instability of CdSe/ZnS quantum dots (QDs) has been studied under varied conditions. We discussed the main features of the evolution of photoluminescence (PL) intensity and energy at different laser powers, which showed critical dependences on the environment. The PL red shift in a vacuum showed strong temperature dependence, from which we concluded that the thermal activation energy for trapping states of the charge carriers was about 14.7 meV. Furthermore, the PL spectra showed asymmetric evolution during the laser irradiation, for which two possible explanations were discussed. Those results provided a comprehensive picture for the photo-instability of the colloidal QDs under different conditions.

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

    DOE Patents [OSTI]

    Gessert, T.A.

    1999-06-01

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

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

    DOE Patents [OSTI]

    Gessert, Timothy A. (Conifer, CO)

    1999-01-01

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

  1. Electrical and photovoltaic properties of CdTe/ZnTe n-i-p junctions grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Zielony, E., E-mail: eunika.zielony@pwr.edu.pl; P?aczek-Popko, E.; Racino, A.; Gumienny, Z. [Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Olender, K.; Wosi?ski, T.; Karczewski, G.; Chusnutdinow, S. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2014-06-28

    Preliminary studies have been performed on photoelectrical properties of CdTe/ZnTe n-i-p junctions grown using the molecular beam epitaxy technique. Photovoltaic properties of the cells have been investigated by the measurements of current-voltage (I-V) characteristics under 1-sun illumination. I-V characteristics yield efficiencies of the cells varying from 3.4% to 4.9%. The low efficiency can be due to the presence of electrically active defects. In order to study the origin of defects in CdTe/ZnTe photovoltaic junctions, space charge techniques (C-V and deep level transient spectroscopy (DLTS)) have been applied. From the C-V measurements, a doping profile was calculated confirming charge accumulation in the i-CdTe layer. The results of the DLTS studies revealed the presence of four traps within a temperature range from 77–420?K. Three of them with activation energies equal to 0.22 eV, 0.45?eV, and 0.78?eV have been ascribed to the hole traps present in the i-CdTe material and their possible origin has been discussed. The fourth, high-temperature DLTS peak observed at ?350?K has been attributed to extended defects as its amplitude and temperature position depends on the value of the filling pulse width. It is assumed that the defects related to the trap are either located in the i-CdTe layer or at the i-CdTe/ZnTe interface. However, it was found that the trap exhibits twofold nature: it behaves as a majority or as a minority trap, depending on the filling pulse height, which is a characteristic feature of recombination centers. This trap is presumably responsible for the low efficiency of the cells.

  2. Investigation of the Effect of I-ZnO Window Layer on the Device Performance of the Cd-Free CIGS Based Solar Cells: Preprint

    SciTech Connect (OSTI)

    Hasoon, F. S.; Al-Thani, H. A.; Li, X.; Kanevce, A.; Perkins, C.; Asher, S.

    2008-05-01

    This paper focuses on preparing Cd-free, CIGS-based solar cells with intrinsic high resistivity ZnO (I-ZnO) films deposited by metal-organic chemical vapor deposition (MOCVD) technique at different deposition substrate temperature and I-ZnO film thickness, and the effect of the prior treatment of CIGS films by ammonium hydroxide (NH4OH) diluted solution on the device performance.

  3. Selective Zn2+ sensing using a modified bipyridine complex

    SciTech Connect (OSTI)

    Akula, Mahesh; El-Khoury, Patrick Z.; Nag, Amit; Bhattacharya, Anupam

    2014-06-01

    A novel fluorescent Zn2+ sensor, 4-(pyridin-2-yl)-3H-pyrrolo[2, 3-c]quinoline (PPQ), has been designed, synthesized and characterized by various spectroscopic and analytical techniques. PPQ exhibits superior detection of Zn2+ in the presence of various cations tested, including Cd2+ and Hg2+, via wavelength shifted fluorescence intensity enhancement. The emission wavelength at 500 nm, ensures probable noninterference from cellular components while performing biological applications.

  4. FLEXIBLE CdTe SOLAR CELLS BY A LOW TEMPERATURE PROCESS ON ITO/ZnO COATED A. Salavei, I. Rimmaudo, F. Piccinelli1

    E-Print Network [OSTI]

    Romeo, Alessandro

    FLEXIBLE CdTe SOLAR CELLS BY A LOW TEMPERATURE PROCESS ON ITO/ZnO COATED POLYMERS A. Salavei, I will be discussed. Keywords: Flexible Substrate, CdTe, ITO, Laser Processing, Thin Film Solar Cell 1 INTRODUCTION Thin film solar cells deposited on a flexible substrate are easier to integrate in buildings; they also

  5. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors

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

    Egarievwe, Stephen U.; Yang, Ge; Egarievwe, Alexander; Okwechime, Ifechukwude O.; Gray, Justin; Hales, Zaveon M.; Hossain, Anwar; Camarda, Guiseppe S.; Bolotnikov, Aleksey E.; James, Ralph B.

    2015-02-11

    Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and cadmium manganese telluride (CdMnTe or CMT) crystals often have Te inclusions that limit their performances as X-ray- and gamma-ray-detectors. We present here the results of post-growth thermal annealing aimed at reducing and eliminating Te inclusions in them. In a 2D analysis, we observed that the sizes of the Te inclusions declined to 92% during a 60-h annealing of CZT at 510 °C under Cd vapor. Further, tellurium inclusions were eliminated completely in CMT samples annealed at 570 °C in Cd vapor for 26 h, whilst their electrical resistivity fell by an ordermore »of 102. During the temperature-gradient annealing of CMT at 730 °C and an 18 °C/cm temperature gradient for 18 h in a vacuum of 10-5 mbar, we observed the diffusion of Te from the sample, causing a reduction in size of the Te inclusions. For CZT samples annealed at 700 °C in a 10 °C/cm temperature gradient, we observed the migration of Te inclusions from a low-temperature region to a high one at 0.022 ?m/s. During the temperature-gradient annealing of CZT in a vacuum of 10-5 mbar at 570 °C and 30 °C/cm for 18 h, some Te inclusions moved toward the high-temperature side of the wafer, while other inclusions of the same size, i.e., 10 µm in diameter, remained in the same position. These results show that the migration, diffusion, and reaction of Te with Cd in the matrix of CZT- and CMT-wafers are complex phenomena that depend on certain conditions.« less

  6. Study of asymmetries of Cd(Zn)Te devices investigated using photo-induced current transient spectroscopy, Rutherford backscattering, surface photo-voltage spectroscopy, and gamma ray spectroscopies

    SciTech Connect (OSTI)

    Crocco, J.; Bensalah, H.; Zheng, Q.; Dieguez, E.; Corregidor, V.; Avles, E.; Castaldini, A.; Fraboni, B.; Cavalcoli, D.; Cavallini, A.; Vela, O.

    2012-10-01

    Despite these recent advancements in preparing the surface of Cd(Zn)Te devices for detector applications, large asymmetries in the electronic properties of planar Cd(Zn)Te detectors are common. Furthermore, for the development of patterned electrode geometries, selection of each electrode surface is crucial for minimizing dark current in the device. This investigation presented here has been carried out with three objectives. Each objective is oriented towards establishing reliable methods for the selection of the anode and cathode surfaces independent of the crystallographic orientation. The objectives of this study are (i) investigate how the asymmetry in I-V characteristics of Cd(Zn)Te devices may be associated with the TeO2 interfacial layer using Rutherford backscattering to study the structure at the Au-Cd(Zn)Te interface, (ii) develop an understanding of how the concentration of the active traps in Cd(Zn)Te varies with the external bias, and (iii) propose non-destructive methods for selection of the anode and cathode which are independent of crystallographic orientation. The spectroscopic methods employed in this investigation include Rutherford backscattering spectroscopy, photo-induced current transient spectroscopy, and surface photo-voltage spectroscopy, as well as gamma ray spectroscopy to demonstrate the influence on detector properties.

  7. Pulse-shape discrimination of surface events in CdZnTe detectors for the COBRA experiment

    E-Print Network [OSTI]

    Matthew Fritts; Jan Tebrügge; Jürgen Durst; Joachim Ebert; Claus Gößling; Thomas Göpfert; Daniel Gehre; Caren Hagner; Nadine Heidrich; Michael Homann; Tobias Köttig; Till Neddermann; Christian Oldorf; Thomas Quante; Silke Rajek; Oscar Reinecke; Oliver Schulz; Jan Timm; Björn Wonsak; Kai Zuber

    2014-01-23

    Events near the cathode and anode surfaces of a coplanar grid CdZnTe detector are identifiable by means of the interaction depth information encoded in the signal amplitudes. However, the amplitudes cannot be used to identify events near the lateral surfaces. In this paper a method is described to identify lateral surface events by means of their pulse shapes. Such identification allows for discrimination of surface alpha particle interactions from more penetrating forms of radiation, which is particularly important for rare event searches. The effectiveness of the presented technique in suppressing backgrounds due to alpha contamination in the search for neutrinoless double beta decay with the COBRA experiment is demonstrated.

  8. Influence of the thickness of a crystal on the electrical characteristics of Cd(Zn)Te detectors

    SciTech Connect (OSTI)

    Sklyarchuk, V.; Fochuk, p.; Rarenko, I.; Zakharuk, Z.; Sklyarchuk, O. F.; Bolotnikov, A. E.; James, R. B.

    2015-08-01

    We studied the electrical characteristics of Cd(Zn)Te detectors with rectifying contacts and varying thicknesses, and established that their geometrical dimensions affect the measured electrical properties. We found that the maximum value of the operating-bias voltage and the electric field in the detector for acceptable values of the dark current can be achieved when the crystal has an optimum thickness. This finding is due to the combined effect of generation-recombination in the space-charge region and space-charge limited currents (SCLC).

  9. Voltage-induced electroluminescence characteristics of hybrid light-emitting diodes with CdSe/Cd/ZnS core-shell nanoparticles embedded in a conducting polymer on plastic substrates

    SciTech Connect (OSTI)

    Kwak, Kiyeol; Cho, Kyoungah, E-mail: chochem@korea.ac.kr, E-mail: sangsig@korea.ac.kr; Kim, Sangsig, E-mail: chochem@korea.ac.kr, E-mail: sangsig@korea.ac.kr [Department of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)] [Department of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2014-03-10

    We investigate the electroluminescence (EL) characteristics of a hybrid light-emitting diode (HyLED) with an emissive layer comprised of CdSe/Cd/ZnS core-shell nanoparticles (NPs) embedded in poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) on a plastic substrate. The EL characteristics change dramatically with increasing of the biased voltage. At low voltages, recombination of electrons and holes occurs only in the PFO film because of poor charge transfer in the PFO-CdSe/Cd/ZnS NPs composite film, while the color of the light-emitting from the HyLED changes from blue to red as the biased voltage increases from 7.5 to 17.5?V. We examine and discuss the mechanism of this color tunability.

  10. TiO2 Nanotubes with a ZnO Thin Energy Barrier for Improved Current Efficiency of CdSe Quantum-Dot-Sensitized Solar Cells

    SciTech Connect (OSTI)

    Lee, W.; Kang, S. H.; Kim, J. Y.; Kolekar, G. B.; Sung, Y. E.; Han, S. H.

    2009-01-01

    This paper reports the formation of a thin ZnO energy barrier between a CdSe quantum dot (Q dots) sensitizer and TiO{sub 2} nanotubes (TONTs) for improved current efficiency of Q dot-sensitized solar cells. The formation of a ZnO barrier between TONTs and the Q dot sensitizer increased the short-circuit current under illumination and also reduced the dark current in a dark environment. The power conversion efficiency of Q dot-sensitized TONT solar cells increased by 25.9% in the presence of the ZnO thin layer due to improved charge-collecting efficiency and reduced recombination.

  11. CD

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits &Bradbury Science Museum6 Shares1-0005-000CD .... -- en .. CD :II

  12. Comparison of Pb, Zn, Cd, As, Cr, Mo and Sb Adsorption onto Natural Surface Coatings in a Stream Draining Natural As

    E-Print Network [OSTI]

    Comparison of Pb, Zn, Cd, As, Cr, Mo and Sb Adsorption onto Natural Surface Coatings in a Stream Science+Business Media New York 2014 Abstract Natural surface coatings (biofilms) were col- lected elements Á Distribution coefficient Á Biogenic Mn oxide Natural surface coatings are ubiquitous

  13. Use of high-granularity position sensing to correct response non-uniformities of CdZnTe detectors

    SciTech Connect (OSTI)

    Bolotnikov, A. E. Camarda, G. S.; Cui, Y.; De Geronimo, G.; Fried, J.; Hossain, A.; Mahler, G.; Maritato, M.; Marshall, M.; Roy, U.; Vernon, E.; Yang, G.; James, R. B.; Lee, K.; Petryk, M.

    2014-06-30

    CdZnTe (CZT) is a promising medium for room-temperature gamma-ray detectors. However, the low production yield of acceptable quality crystals hampers the use of CZT detectors for gamma-ray spectroscopy. Significant efforts have been directed towards improving quality of CZT crystals to make them generally available for radiation detectors. Another way to address this problem is to implement detector designs that would allow for more accurate and predictable correction of the charge loss associated with crystal defects. In this work, we demonstrate that high-granularity position-sensitive detectors can significantly improve the performance of CZT detectors fabricated from CZT crystals with wider acceptance boundaries, leading to an increase of their availability and expected decrease in cost.

  14. An effect of the networks of the subgrain boundaries on spectral responses of thick CdZnTe detectors

    SciTech Connect (OSTI)

    Bolotnikov, A.; Butcher, J.; Camarda, G.; Cui, Y.; Egarievwe, S.; Fochuk, P.; Gul,R.; Hamade, M.; Hossain, A.; Kim, K.; Kopach,O.; Petryk, M.; Raghothamachar, B.; Yang, G.; and James, R.B.

    2011-08-12

    CdZnTe (CZT) crystals used for nuclear-radiation detectors often contain high concentrations of subgrain boundaries and networks of poligonized dislocations that can significantly degrade the performance of semiconductor devices. These defects exist in all commercial CZT materials, regardless of their growth techniques and their vendor. We describe our new results from examining such detectors using IR transmission microscopy and white X-ray beam diffraction topography. We emphasize the roles on the devices performances of networks of subgrain boundaries with low dislocation densities, such as poligonized dislocations and mosaic structures. Specifically, we evaluated their effects on the gamma-ray responses of thick, >10 mm, CZT detectors. Our findings set the lower limit on the energy resolution of CZT detectors containing dense networks of subgrain boundaries, and walls of dislocations.

  15. Real-structure effects: Band gaps of Mg_xZn_{1-x}O, Cd_xZn_{1-x}O, and n-type ZnO from ab-initio calculations

    SciTech Connect (OSTI)

    Schleife, A; Bechstedt, F

    2012-02-15

    Many-body perturbation theory is applied to compute the quasiparticle electronic structures and the optical-absorption spectra (including excitonic effects) for several transparent conducting oxides. We discuss HSE+G{sub 0}W{sub 0} results for band structures, fundamental band gaps, and effective electron masses of MgO, ZnO, CdO, SnO{sub 2}, SnO, In{sub 2}O{sub 3}, and SiO{sub 2}. The Bethe-Salpeter equation is solved to account for excitonic effects in the calculation of the frequency-dependent absorption coefficients. We show that the HSE+G{sub 0}W{sub 0} approach and the solution of the Bethe-Salpeter equation are very well-suited to describe the electronic structure and the optical properties of various transparent conducting oxides in good agreement with experiment.

  16. MgSe/ZnSe/CdSe coupled quantum wells grown on InP substrate with intersubband absorption covering 1.55??m

    SciTech Connect (OSTI)

    Chen, Guopeng; Shen, Aidong; De Jesus, Joel; Tamargo, Maria C.

    2014-12-08

    The authors report the observation of intersubband (ISB) transitions in the optical communication wavelength region in MgSe/ZnSe/CdSe coupled quantum wells (QWs). The coupled QWs were grown on InP substrates by molecular beam epitaxy. By inserting ZnSe layers to compensate the strain, samples with high structural quality were obtained, as indicated by well resolved satellite peaks in high-resolution x-ray diffraction. The observed ISB transition energies agree well with the calculated values.

  17. In situ capping for size control of monochalcogenides (ZnS, CdS, and SnS) nanocrystals produced by anaerobic metal-reducing bacteria

    SciTech Connect (OSTI)

    Jang, Gyoung Gug; Jacobs, Christopher B; Ivanov, Ilia N; Joshi, Pooran C; Meyer III, Harry M; Kidder, Michelle; Armstrong, Beth L; Datskos, Panos G; Graham, David E; Moon, Ji Won

    2015-01-01

    Metal monochalcogenide quantum dot nanocrystals of ZnS, CdS and SnS were prepared by anaerobic, metal-reducing bacteria using in situ capping by oleic acid or oleylamine. The capping agent preferentially adsorbs on the surface of the nanocrystal, suppressing the growth process in the early stages, thus leading to production of nanocrystals with a diameter of less than 5 nm.

  18. Structural, elastic, electronic and phonon properties of SnX{sub 2}O{sub 4} (X=Mg, Zn, Cd) spinel from density functional theory

    SciTech Connect (OSTI)

    U?ur, Gökay; Candan, Abdullah

    2014-10-06

    First-principle calculations of structural, electronic, elastic and phonon properties of SnMg{sub 2}O{sub 4}, SnZn{sub 2}O{sub 4} and SnCd{sub 2}O{sub 4} compounds are presented, using the pseudo-potential plane waves approach based on density functional theory (DFT) within the generalized gradient approximation (GGA). The computed ground state structural parameters, i.e. lattice constants, internal free parameter and bulk modulus are in good agreement with the available theoretical results. Our calculated elastic constants are indicative of stability of SnX{sub 2}O{sub 4} (X=Mg, Zn, Cd) compounds in the spinel structure. The partial density of states (PDOS) of these compounds is in good agreement with the earlier ab-initio calculations. The phonon dispersion relations were calculated using the direct method. Phonon dispersion results indicate that SnZn{sub 2}O{sub 4} is dynamically stable, while SnMg{sub 2}O{sub 4} and SnCd{sub 2}O{sub 4} are unstable.

  19. CdSe/ZnS quantum dots based electrochemical immunoassay for the detection of phosphorylated bovine serum albumin

    SciTech Connect (OSTI)

    Pinwattana, Kulwadee; Wang, Jun; Lin, Chiann Tso; Wu, Hong; Du, Dan; Lin, Yuehe; Chailapakul, Orawon

    2010-11-15

    A CdSe/ZnS quantum dot (QD) based electrochemical immunoassay of phosphorylated bovine serum albumin as a protein biomarker is presented. The QDs were used as labels and were conjugated with the secondary anti-phosphoserine antibody in a heterogeneous sandwich immunoassay. First, the primary BSA antibody was immobilized on polystyrene microwells, followed by the addition of BSA-OP. After that, the QD-labeled anti-phosphoserine antibody was added into microwells for immunorecognition. Finally, the bound QD was dissolved in an acid-dissolution step and was detected by electrochemical stripping analysis. The measured current responses were proportional to the concentration of BSA-OP. Under optimal conditions, the voltammetric response was linear over the range of 0.5 - 500 ng mL-1 of BSA-OP, with a detection limit of 0.5 ng mL-1 at a deposition potential of -1.2 V for 120 s. It also shows good reproducibility with a relative standard deviation of 8.6% of six times determination of 25 ng mL-1 of BSA-OP. This QD-based electrochemical immunoassay offers great promise for simple and cost-effective analysis of protein biomarkers.

  20. Preparation of water soluble L-arginine capped CdSe/ZnS QDs and their interaction with synthetic DNA: Picosecond-resolved FRET study

    SciTech Connect (OSTI)

    Giri, Anupam; Goswami, Nirmal; Lemmens, Peter; Pal, Samir Kumar

    2012-08-15

    Graphical abstract: Förster resonance energy transfer (FRET) studies on the interaction of water soluble arginine-capped CdSe/ZnS QDs with ethidium bromide (EB) labeled synthetic dodecamer DNA. Highlights: ? We have solubilized CdSe/ZnS QD in water replacing their TOPO ligand by L-arginine. ? We have studied arginine@QD–DNA interaction using FRET technique. ? Arginine@QDs act as energy donor and ethidium bromide-DNA acts as energy acceptor. ? We have applied a kinetic model to understand the kinetics of energy transfer. ? Circular dichroism studies revealed negligible perturbation in the DNA B-form in the arg@QD-DNA complex. -- Abstract: We have exchanged TOPO (trioctylphosphine oxide) ligand of CdSe/ZnS core/shell quantum dots (QDs) with an amino acid L-arginine (Arg) at the toluene/water interface and eventually rendered the QDs from toluene to aqueous phase. We have studied the interaction of the water soluble Arg-capped QDs (energy donor) with ethidium (EB) labeled synthetic dodecamer DNA (energy acceptor) using picoseconds resolved Förster resonance energy transfer (FRET) technique. Furthermore, we have applied a model developed by M. Tachiya to understand the kinetics of energy transfer and the distribution of acceptor (EB-DNA) molecules around the donor QDs. Circular dichroism (CD) studies revealed a negligible perturbation in the native B-form structure of the DNA upon interaction with Arg-capped QDs. The melting and the rehybridization pathways of the DNA attached to the QDs have been monitored by the CD which reveals hydrogen bonding is the associative mechanism for interaction between Arg-capped QDs and DNA.

  1. Effect of annealing on the kinetic properties and band parameters of Hg{sub 1?x?y}Cd{sub x}Eu{sub y}Se semiconductor crystals

    SciTech Connect (OSTI)

    Kovalyuk, T. T. Maistruk, E. V.; Maryanchuk, P. D.

    2014-12-15

    The results of studies of the kinetic properties of Hg{sub 1?x?y}Cd{sub x}Eu{sub y}Se semiconductor crystals in the ranges of temperatures T = 77–300 K and magnetic fields H = 0.5–5 kOe before and after heat treatment of the samples in Se vapors are reported. It is established that annealing of the samples in Se vapors induces a decrease in the electron concentration. From the concentration dependence of the electron effective mass at the Fermi level, the band gap, the matrix element of interband interaction, and the electron effective mass at the bottom of the conduction band are determined.

  2. Acceptor and donor production in Hg b1 s[subscript -x]Cd[subscript x]Te by neutron transmutation doping 

    E-Print Network [OSTI]

    Seager, Kevin Douglas

    1985-01-01

    ACCEPTOR AND DONOR PRODUCTION IN Hgi ?Cd?Te BY NEUTRON TRANSMUTATION DOPING A Thesis by KEVIN DOUGLAS SEAGFR Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1985 Majon Subject: Nuclear Fngineer ing ACCEPTOR AND DONOR PRODUCTION IN Hgl-xCdxTe BY NEUTRON TRANSMUTATION DOPING A Thesis by KEVIN DOUGLAS SEAGER Approved as to style and content by: Ron R. Hart (Chairman of Committee...

  3. COMPARISON OF TRAP STATES BETWEEN CIGSS/CdS/ZnO AND Cd PE CIGSS/ZnO CELLS P.K. Johnson, A.O. Pudov, J.R. Sites

    E-Print Network [OSTI]

    Sites, James R.

    (CIGS) thin films were treated in Cd solutions (Cd PE treatment) yielded solar cells with efficiencies surface can produce a cell comparable to the best CdS/CIGS cells. We extend this work to include CIGSS Defects - 3 1. INTRODUCTION Polycrystalline CIGS thin film photovoltaic cells are known for their high

  4. Near-Infrared Photoluminescence Enhancement in Ge/CdS and Ge/ZnS Core/Shell Nanocrystals: Utilizing IV/II-VI Semiconductor Epitaxy

    SciTech Connect (OSTI)

    Guo, Yijun [Ames Laboratory; Rowland, Clare E [Argonne National Laboratory; Schaller, Richard D [Argonne National Laboratory; Vela, Javier [Ames Laboratory

    2014-08-26

    Ge nanocrystals have a large Bohr radius and a small, size-tunable band gap that may engender direct character via strain or doping. Colloidal Ge nanocrystals are particularly interesting in the development of near-infrared materials for applications in bioimaging, telecommunications and energy conversion. Epitaxial growth of a passivating shell is a common strategy employed in the synthesis of highly luminescent II–VI, III–V and IV–VI semiconductor quantum dots. Here, we use relatively unexplored IV/II–VI epitaxy as a way to enhance the photoluminescence and improve the optical stability of colloidal Ge nanocrystals. Selected on the basis of their relatively small lattice mismatch compared with crystalline Ge, we explore the growth of epitaxial CdS and ZnS shells using the successive ion layer adsorption and reaction method. Powder X-ray diffraction and electron microscopy techniques, including energy dispersive X-ray spectroscopy and selected area electron diffraction, clearly show the controllable growth of as many as 20 epitaxial monolayers of CdS atop Ge cores. In contrast, Ge etching and/or replacement by ZnS result in relatively small Ge/ZnS nanocrystals. The presence of an epitaxial II–VI shell greatly enhances the near-infrared photoluminescence and improves the photoluminescence stability of Ge. Ge/II–VI nanocrystals are reproducibly 1–3 orders of magnitude brighter than the brightest Ge cores. Ge/4.9CdS core/shells show the highest photoluminescence quantum yield and longest radiative recombination lifetime. Thiol ligand exchange easily results in near-infrared active, water-soluble Ge/II–VI nanocrystals. We expect this synthetic IV/II–VI epitaxial approach will lead to further studies into the optoelectronic behavior and practical applications of Si and Ge-based nanomaterials.

  5. Zinc concentration effect on structural, optical and electrical properties of Cd{sub 1?x}Zn{sub x}Se thin films

    SciTech Connect (OSTI)

    Akaltun, Yunus; Y?ld?r?m, M. Ali; Ate?, Aytunç; Y?ld?r?m, Muhammet

    2012-11-15

    Highlights: ? Cd{sub 1?x}Zn{sub x}Se thin films were deposited using SILAR method. ? The electron effective mass, refractive index, dielectric constant values were calculated by using the energy bandgap values as a function of the zinc concentration (x). ? The resistivity and activation energy changed as a function of the zinc concentration (x). -- Abstract: Cd{sub 1?x}Zn{sub x}Se thin films with different compositions (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were deposited on glass substrates using successive ionic layer adsorption and reaction (SILAR) method at room temperature and ambient pressure. The zinc concentration (x) effect on the structural, morphological, optical and electrical properties of Cd{sub 1?x}Zn{sub x}Se thin films were investigated. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies showed that all the films exhibited polycrystalline nature and were covered well on glass substrates. The energy dispersive X-ray (EDAX) analysis confirmed nearly stoichiometric deposition of the films. The energy bandgap values were changed from 1.99 to 2.82 eV depending on the zinc concentration. Bowing parameter was calculated as 0.08 eV. The electron effective mass (m{sub e}*/m{sub o}), refractive index (n), optical static and high frequency dielectric constants (?{sub o}, ?{sub ?}) values were calculated by using the energy bandgap values as a function of the zinc concentration. The resistivity values of the films changed between 10{sup 5} and 10{sup 7} ? cm with increasing zinc concentration at room temperature.

  6. Charge trapping and de-trapping in isolated CdSe/ZnS nanocrystals under an external electric field: Indirect evidence for a permanent dipole moment

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

    Zang, Huidong; Cristea, Mihail; Shen, Xuan; Liu, Mingzhao; Camino, Fernando; Cotlet, Mircea

    2015-08-05

    Single nanoparticle studies of charge trapping and de-trapping in core/shell CdSe/ZnS nanocrystals incorporated into an insulating matrix and subjected to an external electric field demonstrate the ability to reversibly modulate the exciton dynamics and photoluminescence blinking while providing indirect evidence for the existence of a permanent ground state dipole moment in such nanocrystals. A model assuming the presence of energetically deep charge traps physically aligned along the direction of the permanent dipole is proposed in order to explain the dynamics of nanocrystal blinking in the presence of a permanent dipole moment.

  7. Fluorescent CdSe/ZnS nanocrystal-peptide conjugates for long-term, nontoxic imaging and nuclear targeting in living cells

    SciTech Connect (OSTI)

    Chen, Fanqing; Gerion, Daniele

    2004-06-14

    One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. However, most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells ha s not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the transfection of the complex into living cells. By a novel adaptation of commonly used cell transfection techniques for qdots, we were able to introduce and retain the NLS-qdots conjugate in living cells for up to a week without detectable negative cellular effects. Moreover, we can visualize the movement of the CdSe/ZnS nanocrystal-peptide conjugates from cytoplasm to the nucleus, and the accumulation of the complex in the cell nucleus, over a long observation time period. This report opens the door for using qdots to visualize long-term biological events that happen in the cell nucleus, and provides a new nontoxic, long-term imaging platform for cell nuclear processes.

  8. Quantum-dot light-emitting diodes utilizing CdSe/ZnS nanocrystals embedded in TiO{sub 2} thin film

    SciTech Connect (OSTI)

    Kang, Seung-Hee; Kumar, Ch. Kiran; Kim, Eui-Tae; Lee, Zonghoon; Kim, Kyung-Hyun; Huh, Chul

    2008-11-10

    Quantum-dot (QD) light-emitting diodes (LEDs) are demonstrated on Si wafers by embedding core-shell CdSe/ZnS nanocrystals in TiO{sub 2} thin films via plasma-enhanced metallorganic chemical vapor deposition. The n-TiO{sub 2}/QDs/p-Si LED devices show typical p-n diode current-voltage and efficient electroluminescence characteristics, which are critically affected by the removal of QD surface ligands. The TiO{sub 2}/QDs/Si system we presented can offer promising Si-based optoelectronic and electronic device applications utilizing numerous nanocrystals synthesized by colloidal solution chemistry.

  9. Persisting impact of historical mining activity to metal (Pb, Zn, Cd, Tl, Hg) and metalloid (As, Sb) enrichment in sediments of the Gardon River,

    E-Print Network [OSTI]

    Cattin, Rodolphe

    in 1976 attributed to a tailings dam failure, and (iii) current levels in 2002 and 2011 similar to those

  10. Photophysics of (CdSe)ZnS Colloidal Quantum Dots in an Aqueous Environment Stabilized with Amino Acids and Genetically-Modified Proteins

    SciTech Connect (OSTI)

    Ai, X.; Xu, Q.; Jones, M.; Song, Q.; Ding, S.-Y.; Ellingson, R. J.; Himmel, M.; Rumbles, G.

    2007-01-01

    Using a combination of two amino acids, histidine and N-acetyl-cysteine, to replace the original organic capping groups of (CdSe)ZnS quantum dots, water-soluble and highly luminescent (CdSe)ZnS quantum dots have been successfully prepared at pH 8. Characterization by steady-state and time-resolved photoluminescence spectroscopy, and transient absorption spectroscopy, demonstrate that the electronic properties of these quantum dots exceed those of the original as-synthesized samples dissolved in a more-conventional organic solvent. Furthermore, these amino acid-stabilized quantum dots have been assembled onto a cellulose substrate via cellulose binding proteins that specifically bind to cellulose and was genetically engineered to harbor dual hexahistidine tags at the N- and C-termini to confer binding with the zinc(II) on the quantum dot surface. The spectroscopic measurements show that the protein-bound quantum dots continue to retain their desirable electronic properties when bound on the substrate. Meanwhile, the specific and very selective binding properties of the proteins have remained effective. (1)Select optimal greenhouse gas (GHG) and petroleum reduction strategies for each fleet location, (2)Meet or exceed Federal fleet GHG and petroleum reduction requirements outlined in the Guidance, (3)Acquire vehicles to support these strategies while minimizing fleet size and vehicle miles traveled (VMT), (4)Refine strategies based on agency performance.

  11. Fluorescence resonance energy transfer measured by spatial photon migration in CdSe-ZnS quantum dots colloidal systems as a function of concentration

    SciTech Connect (OSTI)

    Azevedo, G.; Monte, A. F. G.; Reis, A. F.; Messias, D. N.

    2014-11-17

    The study of the spatial photon migration as a function of the concentration brings into attention the problem of the energy transfer in quantum dot embedded systems. By measuring the photon propagation and its spatial dependence, it is possible to understand the whole dynamics in a quantum dot system, and also improve their concentration dependence to maximize energy propagation due to radiative and non-radiative processes. In this work, a confocal microscope was adapted to scan the spatial distribution of photoluminescence from CdSe-ZnS core-shell quantum dots in colloidal solutions. The energy migration between the quantum dots was monitored by the direct measurement of the photon diffusion length, according to the diffusion theory. We observed that the photon migration length decreases by increasing the quantum dot concentration, this kind of behavior has been regarded as a signature of Förster resonance energy transfer in the system.

  12. Native Defects in CdO and CdCuO Alloys

    E-Print Network [OSTI]

    Speaks, Derrick Tyson

    2011-01-01

    Even  when  CdO  has  not  been  doped  with  donor  atoms, atoms  to  a  CdO  matrix with higher pre?doped mobility curve for doped ZnO as  well  as  for  CdO.     Both  have 

  13. Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach

    SciTech Connect (OSTI)

    Schmidt, Th.; Roventa, E.; Clausen, T.; Flege, J. I.; Alexe, G.; Rosenauer, A.; Hommel, D.; Falta, J.; Bernstorff, S.; Kuebel, C.

    2005-11-15

    The vertical and lateral ordering of stacked CdSe quantum dot layers embedded in ZnS{sub x}Se{sub 1-x} has been investigated by means of grazing incidence small angle x-ray scattering and transmission electron microscopy. Different growth parameters have been varied in order to elucidate the mechanisms leading to quantum dot correlation. From the results obtained for different numbers of quantum dot layers, we conclude on a self-organized process which leads to increasing ordering for progressive stacking. The dependence on the spacer layer thickness indicates that strain induced by lattice mismatch drives the ordering process, which starts to break down for too thick spacer layers in a thickness range from 45 to 80 A. Typical quantum dot distances in a range from about 110 to 160 A have been found. A pronounced anisotropy of the quantum dot correlation has been observed, with the strongest ordering along the [110] direction. Since an increased ordering is found with increasing growth temperature, the formation of stacking faults as an additional mechanism for quantum dot alignment can be ruled out.

  14. Drift time variations in CdZnTe detectors measured with alpha-particles: Their correlation with the detector’s responses

    SciTech Connect (OSTI)

    Bolotnikov A. E.; Butcher, J.; Hamade, M.; Petryk, M.; Bolotnikov, A.; Camarda, G.; Cui, Y.; Hossain, A.; Kim, K.; Yang, G.; and James, R.

    2012-05-14

    Homogeneity of properties related to material crystallinity is a critical parameter for achieving high-performance CdZnTe (CZT) radiation detectors. Unfortunately, this requirement is not always satisfied in today's commercial CZT material due to high concentrations of extended defects, in particular subgrain boundaries, which are believed to be part of the causes hampering the energy resolution and efficiency of CZT detectors. In the past, the effects of subgrain boundaries have been studied in Si, Ge and other semiconductors. It was demonstrated that subgrain boundaries tend to accumulate secondary phases and impurities causing inhomogeneous distributions of trapping centers. It was also demonstrated that subgrain boundaries result in local perturbations of the electric field, which affect the carrier transport and other properties of semiconductor devices. The subgrain boundaries in CZT material likely behave in a similar way, which makes them responsible for variations in the electron drift time and carrier trapping in CZT detectors. In this work, we employed the transient current technique to measure variations in the electron drift time and related the variations to the device performances and subgrain boundaries, whose presence in the crystals were confirmed with white beam X-ray diffraction topography and infrared transmission microscopy.

  15. Temperature- and frequency-dependent dielectric properties of organic–inorganic hybrid compound: (C{sub 6}H{sub 9}N{sub 2}){sub 2}(Hg{sub 0.75}Cd{sub 0.25})Cl{sub 4}

    SciTech Connect (OSTI)

    Elwej, R. Hamdi, M.; Hannachi, N.; Hlel, F.

    2015-02-15

    Highlights: • We have synthesized a new hybrid compound of composition (C6H9N2)2(Hg0.75Cd0.25)Cl4. • The Ac conductivity of the title material was studied as a function of frequency and temperature. • The dielectric data have been analyzed in modulus formalism using KWW. - Abstract: The bis-2-amino-4-picolinium tetrachloromercurate-cadmate compound (C{sub 6}H{sub 9}N{sub 2}){sub 2}(Hg{sub 0.75}Cd{sub 0.25})Cl{sub 4} was prepared by hydrothermal method and characterized by X-ray diffraction (XRD) technique. The electrical properties of the compound were studied using impedance spectroscopy in the frequency and temperature range of 200 Hz–5 MHz and 308–403 K, respectively. The equivalent circuit is modeled by a combination of a parallel Rp//CPE circuit to explain the impedance results. The dielectric data were analyzed using complex electrical modulus M* at various temperatures. The activation energy responsible for the relaxation calculated from the modulus spectra is found to be almost the same as the value obtained from the temperature variation of dc conductivity. The electrical modulus and its scaling behavior are also investigated.

  16. Growth of HgTe Quantum Wells for IR to THz Detectors S. DVORETSKY,1,3

    E-Print Network [OSTI]

    Ganichev, Sergey

    on this research, high-quality (013)-grown HgTe QW structures can be used for all-electric detection of radiation. Detection was demon- strated for various low-power continuous-wave (CW) lasers and high-power THz pulsed laser systems. Key words: Growth, HgTe, HgCdTe, quantum wells (QWs), ellipsometric parameters, MBE, far

  17. Bright three-band white light generated from CdSe/ZnSe quantum dot-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode with high color rendering index

    SciTech Connect (OSTI)

    Jang, Ho Seong; Kwon, Byoung-Hwa; Jeon, Duk Young [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yang, Heesun [Department of Materials Science and Engineering, Hongik University, 72-1, Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of)

    2009-10-19

    In this study, bright three-band white light was generated from the CdSe/ZnSe quantum dot (QD)-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode (WLED). The CdSe/ZnSe core/shell structure was confirmed by energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The CdSe/ZnSe QDs showed high quantum efficiency (79%) and contributed to the high luminous efficiency ({eta}{sub L}) of the fabricated WLED. The WLED showed bright natural white with excellent color rendering property ({eta}{sub L}=26.8 lm/W, color temperature=6140 K, and color rendering index=85) and high stability against the increase in forward bias currents from 20 to 70 mA.

  18. Five new Zn(II) and Cd(II) coordination polymers constructed by 3,5-bis-oxyacetate-benzoic acid: Syntheses, crystal structures, network topologies and luminescent properties

    SciTech Connect (OSTI)

    Jiang Xianrong; Yuan Hongyan; Feng Yunlong

    2012-07-15

    Five Zn(II) and Cd(II) coordination polymers, [Zn{sub 2}(BOABA)(bpp)(OH)]{center_dot}0.5H{sub 2}O (1), [Cd{sub 3}(BOABA){sub 2}(bpp){sub 2}(H{sub 2}O){sub 6}]{center_dot}2H{sub 2}O (2), [Cd{sub 3}(BOABA){sub 2}(2,2 Prime -bipy){sub 3}(H{sub 2}O){sub 4}]{center_dot}5.5H{sub 2}O (3), [CdNa(BOABA)(H{sub 2}O)]{sub 2}{center_dot}H{sub 2}O (4) and [Cd{sub 2}(BOABA)(bimb)Cl(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O (5) (H{sub 3}BOABA=3,5-bis-oxyacetate-benzoic acid, bpp=1,3-bi(4-pyridyl)propane, 2,2 Prime -bipy=2,2 Prime -bipyridine, bimb=1,4-bis(imidazol-1 Prime -yl)butane), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. 1 is an uninodal 4-connected 2D square grid network based on binuclear zinc clusters. 2 is 2D wavelike layer structure and further linked by hydrogen bonds into the final 3D (5,6,6)-connected topology network. 3 is 3-connected 2D topology network and the 2,2 Prime -bipy ligands decorate in two different types. 4 is a (4,8)-connected 2D topology network with heterocaryotic {l_brace}Cd{sub 2}Na{sub 2}{r_brace} clusters and BOABA{sup 3-} ligands. 5 can be rationalized as a (3,10)-connected 3D topology network with tetranuclear {l_brace}Cd{sub 4}Cl{sub 2}{r_brace} clusters and BOABA{sup 3-} ligands. Meanwhile, photoluminescence studies revealed that these five coordination polymers display strong fluorescent emission bands in the solid state at room temperature. - Graphical abstract: Five new d{sup 10} metal(II) coordination polymers based on H{sub 3}BOABA ligand were obtained and characterized. They display different topological structures and luminescent properties. Highlights: Black-Right-Pointing-Pointer Five d{sup 10} metal(II) polymers based on 3,5-bis-oxyacetate-benzoic acid were obtained. Black-Right-Pointing-Pointer The polymers were structurally characterized by single-crystal X-ray diffraction. Black-Right-Pointing-Pointer Polymers 1-5 display different topological structures. Black-Right-Pointing-Pointer They show strong fluorescent emission bands in the solid state.

  19. Experimental investigation of exciton-LO-phonon couplings in CdSe/ZnS core/shell nanorods Holger Lange,1,* Mikhail Artemyev,2

    E-Print Network [OSTI]

    Nabben, Reinhard

    in the field of optoelectronics. CdSe nanorods have interest- ing properties, which lead to possible trioctylphosphine selenide in trioctylphos- phine oxide in the presence of hexadecylphosphonic acid as a surface- lected nanorod samples in a second step in a hexadecilamine/ trioctylphosphine oxide reaction mixture

  20. Influence of irradiation with {gamma}-ray photons on the photoluminescence of Cd{sub 0.9}Zn{sub 0.1}Te crystals preliminarily subjected to the intense radiation of a neodymium laser

    SciTech Connect (OSTI)

    Glinchuk, K. D.; Medvid', A. P.; Mychko, A. M.; Naseka, Yu. M.; Prokhorovich, A. V.; Strilchuk, O. M.

    2013-04-15

    The effect of the preliminary treatment of Cd{sub 0.9}Zn{sub 0.1}Te crystals with high-power pulses of neodymium laser radiation (the power density is {<=}1.8 MW/cm{sup 2}, at a wavelength of 532 nm) on the low-temperature (5 K) photoluminescence induced by {gamma}-ray radiation (the dose was {Phi}{sub {gamma}} = 5 kGy) is studied. The luminescence bands are related to radiation-stimulated donor-acceptor pairs, which include shallow neutral donors and neutral cadmium vacancies stimulated by {gamma}-ray irradiation, the transition of free electrons to neutral cadmium vacancies formed by radiation, and the annihilation of excitons bound to the above vacancies. It is shown that, in the crystals preliminarily treated with laser radiation, the intensity of the {gamma}-ray-stimulated luminescence bands is significantly lower than in crystals not subjected to laser radiation. This fact is accounted for by a decrease in the concentration of cadmium vacancies generated by the {gamma}-ray radiation as a result of their annihilation during the course of their interaction with laser-stimulated defects, in particular, as a consequence of their recombination at laser-stimulated interstitial cadmium atoms.

  1. Synchrotron X-ray 2D and 3D Elemental Imaging of CdSe/ZnS Quantum dot Nanoparticles in Daphnia Magna

    SciTech Connect (OSTI)

    Jackson, B.; Pace, H; Lanzirotti, A; Smith, R; Ranville, J

    2009-01-01

    The potential toxicity of nanoparticles to aquatic organisms is of interest given that increased commercialization will inevitably lead to some instances of inadvertent environmental exposures. Cadmium selenide quantum dots (QDs) capped with zinc sulfide are used in the semiconductor industry and in cellular imaging. Their small size (<10 nm) suggests that they may be readily assimilated by exposed organisms. We exposed Daphnia magna to both red and green QDs and used synchrotron X-ray fluorescence to study the distribution of Zn and Se in the organism over a time period of 36 h. The QDs appeared to be confined to the gut, and there was no evidence of further assimilation into the organism. Zinc and Se fluorescence signals were highly correlated, suggesting that the QDs had not dissolved to any extent. There was no apparent difference between red or green QDs, i.e., there was no effect of QD size. 3D tomography confirmed that the QDs were exclusively in the gut area of the organism. It is possible that the QDs aggregated and were therefore too large to cross the gut wall.

  2. Hg System Assembly and Testing Status

    E-Print Network [OSTI]

    McDonald, Kirk

    ;4VRVS Meeting 8 Nov 2006 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Hydraulic Hose Issue #12;2VRVS Meeting 8 Nov 2006 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Hg Drain & Spill Meeting 8 Nov 2006 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Local Hg Vapor Filters · Hg

  3. Mathematical Model Analysis for Hg Flow

    E-Print Network [OSTI]

    McDonald, Kirk

    Mathematical Model Analysis for Hg Flow Yan Zhan SUNYSB April 20th, 2010 #12;Outline · Introduction ­ Mechanism of Jet Breakup & Atomization ­ Dynamic Problems in Hg Target Flow · Mathematical Model for Hg Flow ­ Parameters ­ Incompressible Flow (No MHD) ­ Incompressible Flow (MHD) ­ Proton Beam Energy Conversion

  4. IDS120j WITHOUT RESISTIVE MAGNETS MODIFYING Hg MODULE ( NEW SH#1 REGION + Hg POOL LENGTH)

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120j WITHOUT RESISTIVE MAGNETS MODIFYING Hg MODULE ( NEW SH#1 REGION + Hg POOL LENGTH) Nicholas CRYO#1 WAS DECIDED DURING THE LAST MEETING AND AN EXTENSION OF THE Hg POOL UPSTREAM UP TO ~ - 100 cm FROM SIMULATIONS WITH MODIFIED Hg POOL AND SH#1 REGION

  5. CD Templates

    Broader source: Energy.gov [DOE]

    EERE has developed templates for CD labels and CD packages. These can be used for all EERE products. Both templates are available as EPS files, which can be downloaded and edited in a graphics package like Adobe Illustrator.

  6. High Power Hg Target Conceptual Design Review

    E-Print Network [OSTI]

    McDonald, Kirk

    OF ENERGY Conceptual Design Review 7-8 Feb 05 Pump Issues · Pump adds heat to Hg - Pump delivers nominal 51 to pump heating only · Max available pump output pressure is 750 psi (50 bar) - Estimated piping system Review 7-8 Feb 05 Pump Energy Balance Pump Heat Direct to Tunnel Heat Input to Hg Flow Losses Energy

  7. Electroluminescence of ZnO-based semiconductor heterostructures

    SciTech Connect (OSTI)

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

    2011-01-31

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

  8. Electrodeposition of Zn based nanostructure thin films for photovoltaic applications

    SciTech Connect (OSTI)

    Al-Bat’hi, S. A. M.

    2015-03-30

    We present here a systematic study on the synthesis thin films of various ZnO, CdO, Zn{sub x}Cd{sub 1-x} (O) and ZnTe nanostructures by electrodeposition technique with ZnCl{sub 2,} CdCl{sub 2} and ZnSO{sub 4} solution as starting reactant. Several reaction parameters were examined to develop an optimal procedure for controlling the size, shape, and surface morphology of the nanostructure. The results showed that the morphology of the products can be carefully controlled through adjusting the concentration of the electrolyte. The products present well shaped Nanorods arrays at specific concentration and temperature. UV-VIS spectroscopy and X-ray diffraction results show that the product presents good crystallinity. A possible formation process has been proposed.

  9. Influence of external electric field on piezotronic effect in ZnO nanowires

    E-Print Network [OSTI]

    Wang, Zhong L.

    Wurtzite and zinc blende structured materials, such as ZnO, ZnS, GaN, CdS, and CdSe, have significant], piezopotential gated transistors [5, 6], LEDs [7], solar cells [8], photodetectors [9], and temperature sensors

  10. ZnCuInS/ZnSe/ZnS Quantum Dot-Based Downconversion Light-Emitting Diodes and Their Thermal Effect

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

    Liu, Wenyan; Zhang, Yu; Ruan, Cheng; Wang, Dan; Zhang, Tieqiang; Feng, Yi; Gao, Wenzhu; Yin, Jingzhi; Wang, Yiding; Riley, Alexis P.; et al

    2015-01-01

    The quantum dot-based light-emitting diodes (QD-LEDs) were fabricated using blue GaN chips and red-, yellow-, and green-emitting ZnCuInS/ZnSe/ZnS QDs. The power efficiencies were measured as 14.0?lm/W for red, 47.1?lm/W for yellow, and 62.4?lm/W for green LEDs at 2.6?V. The temperature effect of ZnCuInS/ZnSe/ZnS QDs on these LEDs was investigated using CIE chromaticity coordinates, spectral wavelength, full width at half maximum (FWHM), and power efficiency (PE). The thermal quenching induced by the increased surface temperature of the device was confirmed to be one of the important factors to decrease power efficiencies while the CIE chromaticity coordinates changed little due to themore »low emission temperature coefficients of 0.022, 0.050, and 0.068?nm/°C for red-, yellow-, and green-emitting ZnCuInS/ZnSe/ZnS QDs. These indicate that ZnCuInS/ZnSe/ZnS QDs are more suitable for downconversion LEDs compared to CdSe QDs.« less

  11. The role of plants in the Hg biogeochemical cycle

    E-Print Network [OSTI]

    Nowak, Robert S.

    Biogeochemical Cycle Hg0RGM Hgp Sources Natural: · Soils G th l A ti Z Anthropogenic: · Coal fired power plants W Cycle Hg0RGM Hgp Factors that control Hg release from soils ­ Light TemperatureTemperature Precipitation ­ Anthropogenic emission sources and secondary formation by id ti f H 0oxidation of Hg0 · Particulate mercury (Hgp

  12. Photooxidation of Hg(0) in Artificial and Natural Waters

    E-Print Network [OSTI]

    Morel, François M. M.

    artificial and natural waters irradiated with a UV-B lamp. No change in Hg speciation was observed in dark waters could represent a net balance between Hg(II) photoreduction and Hg(0) photooxidation oxidized in the dark (7, 8). But it is not known iftheseresultsobtainedwithliquiddropsofHg(0)arerelevant

  13. Magnetic fields of HgMn stars

    E-Print Network [OSTI]

    Hubrig, S; Ilyin, I; Korhonen, H; Schoeller, M; Savanov, I; Arlt, R; Castelli, F; Curto, G Lo; Briquet, M; Dall, T H

    2012-01-01

    The frequent presence of weak magnetic fields on the surface of spotted late-B stars with HgMn peculiarity in binary systems has been controversial during the two last decades. We re-analyse available spectropolarimetric material by applying the moment technique on spectral lines of inhomogeneously distributed elements separately. Furthermore, we present new determinations of the mean longitudinal magnetic field for the HgMn star HD65949 and the hotter analog of HgMn stars, the PGa star HD19400, using FORS2 installed at the VLT. We also give new measurements of the eclipsing system AR Aur with a primary star of HgMn peculiarity which were obtained with the SOFIN spectropolarimeter installed at the Nordic Optical Telescope. We downloaded from the ESO archive the publically available HARPS spectra for eight HgMn stars and one normal and one superficially normal B-type star obtained in 2010. The application of the moment technique to the HARPS and SOFIN spectra allowed us to study the presence of the longitudina...

  14. Hg System Status V.B. Graves

    E-Print Network [OSTI]

    McDonald, Kirk

    LABORATORY U. S. DEPARTMENT OF ENERGY HPU Setup · Hydraulic fluid fill and drain process developed using Friday Meeting4 Aug 2006 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Syringe Pump at ORNL · Hydraulic power unit (HPU) and syringe cylinders delivered to ORNL July 21 - Hg cylinder discharge piping

  15. Hg System Assembly and Testing Status

    E-Print Network [OSTI]

    McDonald, Kirk

    U. S. DEPARTMENT OF ENERGY Hydraulic Hose Issue Corrected · Replaced flex hoses with rigid tubing #12;2VRVS Meeting 22 Nov 2006 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Hg System baseplate #12;3VRVS Meeting 22 Nov 2006 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Basic

  16. Safety Issues for Hg irradiation Experiment siting -

    E-Print Network [OSTI]

    McDonald, Kirk

    1 SC/RP Safety Issues for Hg irradiation Experiment siting - Activation of air and components water retention Activation of air by 40 pulses of 2E13 p corresponds to approx. 1 yr of operation in EHN1. Lack of beam dump leads to unnecessary activation of components and aggravates air activation #12

  17. High Efficiency Single Crystal CdTe Solar Cells: November 19, 2009 - January 31, 2011

    SciTech Connect (OSTI)

    Carmody, M.; Gilmore, A.

    2011-05-01

    The goal of the program was to develop single crystal CdTe-based top cells grown on Si solar cells as a platform for the subsequent manufacture of high efficiency tandem cells for CPV applications. The keys to both the single junction and the tandem junction cell architectures are the ability to grow high quality single-crystal CdTe and CdZnTe layers on p-type Si substrates, to dope the CdTe and CdZnTe controllably, both n and p-type, and to make low resistance ohmic front and back contacts. EPIR demonstrated the consistent MBE growth of CdTe/Si and CdZnTe/Si having high crystalline quality despite very large lattice mismatches; epitaxial CdTe/Si and CdZnTe/Si consistently showed state-of-the-art electron mobilities and good hole mobilities; bulk minority carrier recombination lifetimes of unintentionally p-doped CdTe and CdZnTe grown by MBE on Si were demonstrated to be consistently of order 100 ns or longer; desired n- and p-doping levels were achieved; solar cell series specific resistances <10 ?-cm2 were achieved; A single-junction solar cell having a state-of-the-art value of Voc and a unverified 16.4% efficiency was fabricated from CdZnTe having a 1.80 eV bandgap, ideal for the top junction in a tandem cell with a Si bottom junction.

  18. Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal...

    Open Energy Info (EERE)

    Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Areas Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Hg Anomalies In...

  19. Surfaceplasmon-coupled photoluminescence from CdS nanoparticles with Au films

    E-Print Network [OSTI]

    Park, Byungwoo

    , such as light emitting diodes (LEDs), sensor technology, solar cells, and nanophosphors [1­8]. Surface plasmon nano- particle arrays, the fluorescence of CdSe/ZnS core/shell quantum dots was enhanced by 30- and 50

  20. IDS120j WITHOUT RESISTIVE MAGNETS MODIFYING Hg MODULE ( UPDATED )

    E-Print Network [OSTI]

    McDonald, Kirk

    Hg POOL. *********************************************************** >SIMULATIONS CODE: mars1512 OVERVIEW (LEFT), POOL REGION DETAILS (RIGHT). [20 cm GAPS] SH#1 SH#1 SH#1A SH#2 SH#1A Hg POOL SH#4 SH#3 Hg POOL SH#1 2 cm THICK STST OUTER TUBE CRYO#1 CRYO#4CRYO#3 CRYO#2 2 cm THICK STST BEAM PIPE BEAM PIPE

  1. Atom-probe tomographic study of interfaces of Cu{sub 2}ZnSnS{sub 4} photovoltaic cells

    SciTech Connect (OSTI)

    Tajima, S. Asahi, R.; Itoh, T.; Hasegawa, M.; Ohishi, K.; Isheim, D.; Seidman, D. N.

    2014-09-01

    The heterophase interfaces between the CdS buffer layer and the Cu{sub 2}ZnSnS{sub 4} (CZTS) absorption layers are one of the main factors affecting photovoltaic performance of CZTS cells. We have studied the compositional distributions at heterophase interfaces in CZTS cells using three-dimensional atom-probe tomography. The results demonstrate: (a) diffusion of Cd into the CZTS layer; (b) segregation of Zn at the CdS/CZTS interface; and (c) a change of oxygen and hydrogen concentrations in the CdS layer depending on the heat treatment. Annealing at 573?K after deposition of CdS improves the photovoltaic properties of CZTS cells probably because of the formation of a heterophase epitaxial junction at the CdS/CZTS interface. Conversely, segregation of Zn at the CdS/CZTS interface after annealing at a higher temperature deteriorates the photovoltaic properties.

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

    E-Print Network [OSTI]

    Sites, James R.

    ZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY 1 M.A. Contreras, 2 T. Nakada, 2 M analysis between this type of solar cell and the slightly more efficient ZnO/CdS/Cu(In,Ga)Se2/Mo solar cell for conversion efficiency above 20% in thin-film polycrystalline solar cells. It quantifies the gains in current

  3. Atmospheric mercury (Hg) in the Adirondacks: Concentrations and sources

    SciTech Connect (OSTI)

    Hyun-Deok Choi; Thomas M. Holsen; Philip K. Hopke

    2008-08-15

    Hourly averaged gaseous elemental Hg (GEM) concentrations and hourly integrated reactive gaseous Hg (RGM), and particulate Hg (HgP) concentrations in the ambient air were measured at Huntington Forest in the Adirondacks, New York from June 2006 to May 2007. The average concentrations of GEM, RGM, and HgP were 1.4 {+-} 0.4 ng m{sup -3}, 1.8 {+-} 2.2 pg m{sup -3}, and 3.2 {+-} 3.7 pg m{sup -3}, respectively. RGM represents <3.5% of total atmospheric Hg or total gaseous Hg (TGM: GEM + RGM) and HgP represents <3.0% of the total atmospheric Hg. The highest mean concentrations of GEM, RGM, and HgP were measured during winter and summer whereas the lowest mean concentrations were measured during spring and fall. Significant diurnal patterns were apparent in warm seasons for all species whereas diurnal patterns were weak in cold seasons. RGM was better correlated with ozone concentration and temperature in both warm than the other species. Potential source contribution function (PSCF) analysis was applied to identify possible Hg sources. This method identified areas in Pennsylvania, West Virginia, Ohio, Kentucky, Texas, Indiana, and Missouri, which coincided well with sources reported in a 2002 U.S. mercury emissions inventory. 51 refs., 7 figs., 1 tab.

  4. Improve the open-circuit voltage of ZnO solar cells with inserting ZnS layers by two ways

    SciTech Connect (OSTI)

    Sun, Yunfei; Yang, Jinghai; Yang, Lili; Cao, Jian; Gao, Ming; Zhang, Zhiqiang; Wang, Zhe; Song, Hang

    2013-04-15

    ZnS NPs layers were deposited on ZnO NRs by two different ways. One is spin coating; the other is successive ionic layer adsorption and reaction (SILAR) method. The ZnO NRs/ZnS NPs composites were verified by X-ray diffraction, X-ray photoelectron spectroscopy, and UV–visible spectrophotometer; their morphologies and thicknesses were examined by scanning electron microscopic and transmission electron microscopic images. The CdS quantum dot sensitized solar cells (QDSSCs) were constructed using ZnO NRs/ZnS NPs composites as photoanode and their photovoltaic characteristic was studied by J–V curves. The results indicated that the way of SILAR is more beneficial for retarding the back transfer of electrons to CdS and electrolyte than spin coating method. The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method. When ZnS NPs layer was deposited for 10 times on ZnO NRs, the conversion efficiency of QDSSC shows ?3.3 folds increments of as-synthesized ZnO solar cell. - Graphical abstract: When ZnO nanorods were deposited by ZnS for 10 times, the conversion efficiency of QDSSC shows ?3.3 folds increments of as-synthesized ZnO solar cell. Highlights: ? ZnS layers were deposited with two different ways. ? The way of SILAR is more beneficial for retarding the back transfer of electrons. ? The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method.

  5. Process of [sup 196]Hg enrichment

    DOE Patents [OSTI]

    Grossman, M.W.; Mellor, C.E.

    1993-04-27

    A simple rate equation model shows that by increasing the length of the photochemical reactor and/or by increasing the photon intensity in said reactor, the feedstock utilization of [sup 196]Hg will be increased. Two preferred embodiments of the present invention are described, namely (1) long reactors using long photochemical lamps and vapor filters; and (2) quartz reactors with external UV reflecting films. These embodiments have each been constructed and operated, demonstrating the enhanced utilization process dictated by the mathematical model (also provided).

  6. Process of .sup.196 Hg enrichment

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA); Mellor, Charles E. (Salem, MA)

    1993-01-01

    A simple rate equation model shows that by increasing the length of the photochemical reactor and/or by increasing the photon intensity in said reactor, the feedstock utilization of .sup.196 Hg will be increased. Two preferred embodiments of the present invention are described, namely (1) long reactors using long photochemical lamps and vapor filters; and (2) quartz reactors with external UV reflecting films. These embodiments have each been constructed and operated, demonstrating the enhanced utilization process dictated by the mathematical model (also provided).

  7. Evaluation of HgI[sub 2] detectors for lead detection in paint

    SciTech Connect (OSTI)

    Wang, Y.J.; Iwanczyk, J.S.; Graham, W.R. )

    1993-08-01

    The authors conducted a laboratory study of HgI[sub 2] spectrometers used for in-situ determination of lead on painted surfaces. [sup 109]Cd and [sup 57]Co isotopes have been used to excite lead characteristic x-rays from samples. The energy resolution of HgI[sub 2] detectors in the energy region corresponding to lead K x-rays has been measured. An energy resolution of 880 eV (FWHM) for the 60 keV line from an [sup 241]Am source has been obtained. Measurements using thin film standards ranging from 0.5 mg Pb/cm[sup 2] to 2 mg Pb/cm[sup 2] have been conducted. Detection limits, accuracy and precision of the measurements have been estimated. Based upon a comparison of the results that the authors have obtained with the performance of existing detector technology, the HgI[sub 2] detectors seem to be the best solution for handheld XRF lead analyzers.

  8. Author's personal copy Surface-plasmon-enhanced photoluminescence of CdS nanoparticles with

    E-Print Network [OSTI]

    Park, Byungwoo

    in solar cells, nanophotonics, nanophosphors, etc. [1­9]. Surface-plasmon resonance induced fluorescence increase in CdSe/ZnS core/shell quantum dots using highly-ordered gold nanopatterns [11], and Kanemitsu's group examined the mechanisms of the photoluminescence enhancement and quenching of single CdSe

  9. IDS120j WITHOUT RESISTIVE MAGNETS MODIFYING Hg MODULE

    E-Print Network [OSTI]

    McDonald, Kirk

    OVERVIEW (LEFT), POOL REGION DETAILS (RIGHT). [20 cm GAPS] SH#1 SH#1 SH#1A SH#2 SH#1A Hg POOL SH#4 SH#3 Hg POOL SH#1 2 cm THICK STST OUTER TUBE CRYO#1 CRYO#4CRYO#3 CRYO#2 2 cm THICK STST BEAM PIPE BEAM PIPE EXTENDS HALF WAY UPSTREAM TO THE POOL SH#1 10 cm THICK STST RIGHT FLANGE Hg POOL STARTS ~ 85 cm

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

    E-Print Network [OSTI]

    Cao, Guozhong

    Hierarchically Structured ZnO Nanorods-Nanosheets for Improved Quantum-Dot-Sensitized Solar Cells NR-NS photoelectrode for constructing CdS/ CdSe quantum-dot-sensitized solar cells (QDSCs). This hierarchical structure had two advantages in improving the power conversion efficiency (PCE) of the solar cells

  11. U01HG004279 (D.M.M.), U01HG004261 (E.L.), U01HG004274 (S.H.), and U41HG004269 (L.S.). Awards

    E-Print Network [OSTI]

    .T.N.), the Indiana Genomics Initiative (T.C.K.), H. Smith and the NIDDK genomics core laboratory (B.O.), NIH R01HG

  12. Modeling of electron energy spectra and mobilities in semi-metallic Hg1-xCdxTe quantum wells

    E-Print Network [OSTI]

    Melezhik, E O; Sizov, F F

    2015-01-01

    Electron mobility, energy spectra and intrinsic carrier concentrations in the n-type Hg0.32Cd0.68Te / Hg1-xCdxTe / Hg0.32Cd0.68Te quantum well (QW) in semi-metallic state are numerically modeled. Energy spectra and wave functions were calculated in the framework of the 8-band k-p Hamiltonian. In our model, electron scattering on longitudinal optical phonons, charged impurities, and holes has been taken into account, and the mobility has been calculated by an iterative solution of the Boltzmann transport equation. Our results show that the increase of the electron concentration in the well enhances the screening of the 2D electron gas, decreases the hole concentration, and can ultimately lead to a high electron mobility at liquid nitrogen temperatures. The increase of the electron concentration in the QW could be achieved in situ by delta-doping of barriers or by applying the top-gate potential. Our modeling has shown that for low molar composition x the concentration of holes in the well is high in a wide ran...

  13. CERN Hg Jet System V.B. Graves

    E-Print Network [OSTI]

    McDonald, Kirk

    Delivery System Pump Motor Centrifugal Pump Hg Jet Containment Sump Tank Secondary Containment Target Pump Issues · Pump adds heat to Hg - Pump delivers nominal 51 bhp at 23% efficiency (60 bhp max (30kw) · With an assumed Vol=12liter, T=2.4°F/sec (1.3°C/sec) due to pump heating only · Heat

  14. Growth of superconducting Hg-1212 very-thin films

    E-Print Network [OSTI]

    Wu, Judy; Xie, Y. Y.; Kang, B. W.; Gapud, A. A.; Aytug, T.; Fang, L.

    1999-06-01

    High quality epitaxial HgBa2CaCu2O6+delta (Hg- High 1212) films with thickness less than 100 nm have been successfully synthesized using cation-exchange process. The films show the superconducting transition up to similar to 118 K which is close...

  15. MERIT Hg System Review V.B. Graves

    E-Print Network [OSTI]

    McDonald, Kirk

    in rough vacuum · Full-beam interaction length is 30-cm · Beam line is 120cm above the tunnel floor · Up between the Hg and the tunnel environment · Hydraulic pump will be in adjacent tunnel, personnel in remote/vapor containment - Ports for instruments, Hg fill/drain, hydraulics · Optical diagnostic components - Passive

  16. Elucidate the mechanism(s) of Hg uptake in methylating bacteria and effects on Hg methylation in nature.

    E-Print Network [OSTI]

    Post, Wilfred M.

    Objective · Elucidate the mechanism(s) of Hg uptake in methylating bacteria and effects on Hg, suggesting a possible detoxification mechanism for the formation and export of methylmercury. 1 BER Overview A New Mechanism of Mercury Uptake and Methylation in Anaerobic Bacteria Contact: Jeffra Schaefer

  17. 2 Toxicity and Sources of Pb, Cd, Hg, Cr, As, and Radionuclides

    E-Print Network [OSTI]

    Volesky, Bohumil

    ........................................................................................... 35 2.3.1 Acid Mine Drainage ................................................................................................ 35 2.3.1.1 Chemistry of Acid Mine Water

  18. Large-Area (over 50 cm 50 cm) Freestanding Films of Colloidal InP/ ZnS Quantum Dots

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Large-Area (over 50 cm × 50 cm) Freestanding Films of Colloidal InP/ ZnS Quantum Dots Evren of flexible, freestanding films of InP/ZnS quantum dots (QDs) using fatty acid ligands across very large areas avoiding the need for ligand exchange. When pumped by a blue LED, these Cd-free QD films allow for high

  19. Ab initio description of heterostructural alloys: Thermodynamic and structural properties of MgxZn1-xO and CdxZn1-xO

    E-Print Network [OSTI]

    Schleife, André

    received 4 May 2010; published 17 June 2010 Pseudobinary heterostructural alloys of ZnO with MgO or CdO-coordinated rocksalt rs structure e.g., MgO and CdO under ambient conditions.14,15 Isovalent and isostructural alloys in its own right.1­4 When doped with Al, it plays a role as a transparent conduct- ing oxide in solar

  20. Purification of HgI.sub.2 for nuclear detector fabrication

    DOE Patents [OSTI]

    Schieber, Michael M. (Goleta, CA)

    1978-01-01

    A process for purification of mercuric iodide (HgI.sub.2) to be used as a source material for the growth of detector quality crystals. The high purity HgI.sub.2 raw material is produced by a combination of three stages: synthesis of HgI.sub.2 from Hg and I.sub.2, repeated sublimation, and zone refining.

  1. Spectroscopic variability and magnetic fields of HgMn stars

    E-Print Network [OSTI]

    Hubrig, S; Ilyin, I; Korhonen, H; Savanov, I S; Dall, T; Schoeller, M; Cowley, C R; Briquet, M; Arlt, R

    2011-01-01

    The discovery of exotic abundances, chemical inhomogeneities, and weak magnetic fields on the surface of late B-type primaries in spectroscopic binaries has important implications not only for our understanding of the formation mechanisms of stars with Hg and Mn peculiarities themselves, but also for the general understanding of B-type star formation in binary systems. The origin of the abundance anomalies observed in late B-type stars with HgMn peculiarity is still poorly understood. The connection between HgMn peculiarity and membership in binary and multiple systems is supported by our observations during the last decade. The important result achieved in our studies of a large sample of HgMn stars is the finding that most HgMn stars exhibit spectral variability of various chemical elements, proving that the presence of an inhomogeneous distribution on the surface of these stars is a rather common characteristic and not a rare phenomenon. Further, in the studied systems, we found that all components are che...

  2. Optical properties of ZnO/ZnS and ZnO/ZnTe heterostructures forphotovoltaic applications

    SciTech Connect (OSTI)

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

    2007-05-01

    Although ZnO and ZnS are abundant, stable, environmentallybenign, their band gap energies (3.44 eV, 3.72 eV) are too large foroptimal photovoltaic efficiency. By using band-corrected pseudopotentialdensity-functional theory calculations, we study how the band gap,opticalabsorption, and carrier localization canbe controlled by formingquantum-well like and nanowire-based heterostructures ofZnO/ZnS andZnO/ZnTe. In the case of ZnO/ZnS core/shell nanowires, which can besynthesized using existing methods, we obtain a band gap of 2.07 eV,which corresponds to a Shockley-Quiesser efficiency limitof 23 percent.Based on these nanowire results, we propose that ZnO/ZnScore/shellnanowires can be used as photovoltaic devices with organic polymersemiconductors as p-channel contacts.

  3. Active transport, substrate specificity, and methylation of Hg(II) in anaerobic bacteria

    SciTech Connect (OSTI)

    Schasfer, Jeffra [Princeton University; Rocks, Sara [Princeton University; Zheng, Wang [ORNL; Liang, Liyuan [ORNL; Gu, Baohua [ORNL; Morel, Francois M [ORNL

    2011-01-01

    The formation of methylmercury (MeHg), which is biomagnified in aquatic food chains and poses a risk to human health, is effected by some iron- and sulfate-reducing bacteria (FeRB and SRB) in anaerobic environments. However, very little is known regarding the mechanism of uptake of inorganic Hg by these organisms, in part because of the inherent difficulty in measuring the intracellular Hg concentration. By using the FeRB Geobacter sulfurreducens and the SRB Desulfovibrio desulfuricans ND132 as model organisms, we demonstrate that Hg(II) uptake occurs by active transport. We also establish that Hg(II) uptake by G. sulfurreducens is highly dependent on the characteristics of the thiols that bind Hg(II) in the external medium, with some thiols promoting uptake and methylation and others inhibiting both. The Hg(II) uptake system of D. desulfuricans has a higher affinity than that of G. sulfurreducens and promotes Hg methylation in the presence of stronger complexing thiols. We observed a tight coupling between Hg methylation and MeHg export from the cell, suggesting that these two processes may serve to avoid the build up and toxicity of cellular Hg. Our results bring up the question of whether cellular Hg uptake is specific for Hg(II) or accidental, occurring via some essential metal importer. Our data also point at Hg(II) complexation by thiols as an important factor controlling Hg methylation in anaerobic environments.

  4. HgMn Stars as apparent X-ray emitters

    E-Print Network [OSTI]

    Hubrig, S; Mathys, G

    1998-01-01

    In the ROSAT all-sky survey 11 HgMn stars were detected as soft X-ray emitters (Berghoefer, Schmitt & Cassinelli 1996). Prior to ROSAT, X-ray observations with the Einstein Observatory had suggested that stars in the spectral range B5-A7 are devoid of X-ray emission. Since there is no X-ray emitting mechanism available for these stars (also not for HgMn stars), the usual argument in the case of an X-ray detected star of this spectral type is the existence of an unseen low-mass companion which is responsible for the X-ray emission. The purpose of the present work is to use all available data for our sample of X-ray detected HgMn stars and conclude on the nature of possible companions.

  5. MG DOPING AND ALLOYING IN ZN3P2 HETEROJUNCTION SOLAR CELLS Gregory M. Kimball, Nathan S. Lewis, Harry A. Atwater

    E-Print Network [OSTI]

    Kimball, Gregory

    . In this manuscript, the electronic and material properties of Mg impurities in Zn3P2 are studied by the Hall effect phosphide (Zn3P2) is a promising and earth-abundant alternative to traditional materials (e.g. CdTe, CIGS, a have therefore been constructed from Schottky contacts, p-n semiconductor heterojunctions [4

  6. Experimental study of 199Hg spin anti-relaxation coatings

    E-Print Network [OSTI]

    Z. Chowdhuri; M. Fertl; M. Horras; K. Kirch; J. Krempel; B. Lauss; A. Mtchedlishvili; D. Rebreyend; S. Roccia; P. Schmidt-Wellenburg; G. Zsigmond

    2013-09-04

    We report on a comparison of spin relaxation rates in a $^{199}$Hg magnetometer using different wall coatings. A compact mercury magnetometer was built for this purpose. Glass cells coated with fluorinated materials show longer spin coherence times than if coated with their hydrogenated homologues. The longest spin relaxation time of the mercury vapor was measured with a fluorinated paraffin wall coating.

  7. The new Hg-rich barium indium mercurides BaIn{sub x}Hg{sub 7?x} (x=3.1) and BaIn{sub x}Hg{sub 11?x} (x=0–2.8)

    SciTech Connect (OSTI)

    Wendorff, Marco; Schwarz, Michael; Röhr, Caroline

    2013-07-15

    The title compounds BaIn{sub x}Hg{sub 7?x} (x=3.1(1)) and BaIn{sub x}Hg{sub 11?x} (x=0–2.8) were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures have been determined using single crystal X-ray data. BaIn{sub x}Hg{sub 7?x} (x=3.1(1)) crystallizes in a new structure type (orthorhombic, oC16, space group Cmmm: a=512.02(1), b=1227.68(3), c=668.61(2) pm, Z=2, R1=0.0311). In the structure, the atoms of the three crystallographically different mixed In/Hg positions form planar nets of four-, six- and eight-membered rings. These nets are shifted against each other such that the four-membered rings form empty distorted cubes. The cubes are connected via common edges, corners and folded ladders, which are also found in BaIn{sub 2}/BaHg{sub 2} (KHg{sub 2} structure type) and BaIn (?-NaHg type). The Ba atoms are centered in the eight-membered rings and exhibit an overall coordination number of 20. The [BaM{sub 20}] polyhedra and twice as many distorted [M{sub 8}] cubes tesselate the space. BaIn{sub 2.8}Hg{sub 8.2} (cubic, cP36, space group Pm3{sup ¯}m, a=961.83(1) pm, Z=3, R1=0.0243) is the border compound of the phase width BaIn{sub x}Hg{sub 11?x} of the rare BaHg{sub 11} structure type. In the structure, ideal [M{sub 8}] cubes (at the corners of the unit cell) and BaM{sub 20} polyhedra (at the edges of the unit cell) represent the building blocks comparable to the other new In mercuride. In accordance with the increased In/Hg content, additional M-pure regions appear: the center of the unit cell contains a huge [Hg(1)M(2){sub 12}M(3,4){sub 32}] polyhedron, a Hg-centered cuboctahedron of In/Hg atoms surrounded by a capped cantellated cube of 32 additional M atoms. For both structure types, the bonding situation and the ‘coloring’, i.e. the In/Hg distribution of the polyanionic network, are discussed considering the different sizes of the atoms and the charge distribution (Bader AIM charges), which have been calculated within the framework of FP-LAPW density functional theory. - Graphical abstract: BaIn{sub 2.6}Hg{sub 4.4}: distorted cubes [(In/Hg){sub 8}] (green, like in BaHg{sub 11}), folded ladders (violet, like in BaIn, BaHg{sub 2} and BaIn{sub 2}) and Ba coordination polyhedra [Ba(In/Hg){sub 20}] (blue, like in BaHg{sub 11}). - Highlights: • The Hg-rich In-mercuride BaIn{sub 3.1}Hg{sub 3.9} crystallizes with a singular structure type. • The phase width of the BaHg{sub 11} structure in BaIn{sub x}Hg{sub 11-x} ends at x=2.8. • The relations of both compounds with other alkaline-earth mercurides are outlined. • The Hg/In coloring of the polyanion is discussed considering the structure features. • Bonding aspects are explored using band structure calculations.

  8. IDS120hm GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING WITHOUT/WITH

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120hm GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING WITHOUT: (m IS FOR) modified Hg pool vessel IN IDS120h. # WITHOUT AND WITH Hg IN THE POOL SIMULATIONS Hg POOL VESSEL AND SHIFTED Be WIDOW FROM 600 cm (0.6 cm THICK) TO 300 cm (1 cm THICK). MODIFIED Hg

  9. Saving work to a CD-R using the Optical CD Drive (CD Burner) The new Workstations in the Knowledge Common are equipped with CD Burners

    E-Print Network [OSTI]

    Machel, Hans

    Saving work to a CD-R using the Optical CD Drive (CD Burner) The new Workstations in the Knowledge Common are equipped with CD Burners and when you insert a CD (whether CD-R or CD-RW) into the drive

  10. Narrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence

    E-Print Network [OSTI]

    Russell, Kasey

    of the optical gap and Burstein-Moss shift in CdO thin films: A consequence of extended misuse of 2-versusNarrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence-like opto-electronic properties Appl. Phys. Lett. 99, 141917 (2011) Oxygen enhanced ferromagnetism in Cr-doped

  11. nTOF11 Hg System Design Tony Gabriel, Phil Spampinato

    E-Print Network [OSTI]

    McDonald, Kirk

    delivery system size reduction - Target cart design optimization - Magnet base support #12;6 OAK RIDGE of Hg system using jackbolts · Hg system fixed to top plate, final position locked using nut/bolt #12

  12. High Compositional Homogeneity of CdTexSe1-x Crystals Grown by the Bridgman Method

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

    Roy, U. N.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Hossain, A.; Lee, K.; Lee, W.; Tappero, R.; Yang, G.; Gul, R.; et al

    2015-02-03

    We obtained high-quality CdTexSe1-x (CdTeSe) crystals from ingots grown by the vertical Bridgman technique. The compositional uniformity of the ingots was evaluated by X-ray fluorescence at BNL’s National Synchrotron Light Source X27A beam line. The resulting compositional homogeneity was highly uniform throughout the ingot, and the effective segregation coefficient of Se was ~1.0. This uniformity offers potential opportunity to enhance the yield of the materials for both infrared substrate and radiation-detector applications, so greatly lowering the cost of production and also offering us the prospect to grow large-diameter ingots for use as large-area substrates and for producing higher efficiency gamma-raymore »detectors. The concentration of secondary phases was found to be much lower, by eight- to ten fold compared to that of conventional CdxZn1-xTe (CdZnTe or CZT).« less

  13. Swiss Federal Laboratories for Materials Science and Technology Advances in Thin Film PV: CIGS & CdTe

    E-Print Network [OSTI]

    Canet, Léonie

    and Photovoltaics Thin film solar cells based on compound semiconductor absorbers: CIGS and CdTe High efficiency: http://www.nrel.gov/ncpv/images/efficiency_chart.jpg 20.4% flexible CIGS solar cell record by Empa #12 solar cells 1µm Substrate Mo CIGS Buffer ZnO/ZnO:Al 15 20 25 30 100 300 500 700 900 Cu [at%] t

  14. IDS120j WITHOUT RESISTIVE MAGNETS INTRODUCING A DOUBLE WALL Hg POOL VESSSELAND Be WINDOW.

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120j WITHOUT RESISTIVE MAGNETS INTRODUCING A DOUBLE WALL Hg POOL VESSSELAND Be WINDOW. SC#4 STUDIES FOR 20 cm GAPS SIZE FOR STST IN THE PLACE OF RESISTIVE MAGNETS AND REST OF VOLUME IN Hg POOL SHIELDING IN THE PLACE OF RESISTIVE MAGNETS AND IN THE REST OF VOLUME IN THE Hg POOL VESSEL

  15. Anthropogenic and Natural Emissions of Mercury (Hg) in the northeastern United Jeffrey MacAdam Sigler

    E-Print Network [OSTI]

    Lee, Xuhui

    Abstract Anthropogenic and Natural Emissions of Mercury (Hg) in the northeastern United States impact may depend on the emission rate. Anthropogenic Hg emissions in the United States are poorly characterized. Natural Hg emissions are poorly understood worldwide, due to lack of data or measurement systems

  16. A Free Jet Hg Target Operating in a High Magnetic Field Intersecting

    E-Print Network [OSTI]

    McDonald, Kirk

    , 2005) Sect. A-A Hg Supply Tube Nozzle Solenoid Bore A A Fiber Optic Bundle Hydraulic Fluid Lines Vacuum · Hydraulically-actuated piston pump delivers Hg to the nozzle · Hg cylinder 25-cm (10-inch) bore, 38-cm (15-inch

  17. Synthesis and growth of HgI{sub 2} nanocrystals in a glass matrix: Heat treatment

    SciTech Connect (OSTI)

    Condeles, J. F. E-mail: ricssilva@yahoo.com.br; Silva, R. S. E-mail: ricssilva@yahoo.com.br; Silva, A. C. A.; Dantas, N. O.

    2014-08-14

    Mercury iodide (HgI{sub 2}) nanocrystals (NCs) were successfully grown in a barium phosphate glass matrix synthesized by fusion. Growth control of HgI{sub 2} NCs was investigated by Atomic Force Microscopy (AFM), Optical Absorption (OA), Fluorescence (FL), and X-ray diffraction (XRD). AFM images reveal the formation of HgI{sub 2} nanocrystals in host glass matrix. HgI{sub 2} NCs growth was evidenced by an OA and FL band red-shift with increasing annealing time. XRD measurements revealed the ? crystalline phase of the HgI{sub 2} nanocrystals.

  18. SrAgZn and EuAgZn with KHg{sub 2}-type structure—Structure, magnetic properties, and {sup 151}Eu Mössbauer spectroscopy

    SciTech Connect (OSTI)

    Gerke, Birgit; Rodewald, Ute Ch.; Niehaus, Oliver; Pöttgen, Rainer

    2013-07-15

    Samples of SrAgZn and EuAgZn were synthesized by reaction of the elements in sealed tantalum crucibles. Both structures were refined on the basis of single crystal X-ray diffractometer data: KHg{sub 2}-type, Imma, a=476.7(1), b=780.9(2), c=810.1(2) pm, R{sub 1}/wR{sub 2}=0.0189/0.0119, 381 F² values for SrAg{sub 1.12}Zn{sub 0.88} and a=474.43(9), b=760.8(2), c=799.0(2) pm, R{sub 1}/wR{sub 2}=0.0226/0.0483, 370 F² values for EuAg{sub 1.17}Zn{sub 0.83} with 13 variables per refinement. Silver and zinc are randomly distributed on the Hg position and build up three-dimensional networks. EuAgZn shows ferromagnetic ordering at 29(1) K. In the temperature range from 75 to 300 K the sample shows Curie–Weiss behaviour with ?{sub eff}=7.87(1) ?{sub B}/Eu atom and ?{sub P}=37.1(1) K, indicating divalent europium. {sup 151}Eu Mössbauer spectroscopic measurements confirmed the divalent state with an isomer shift of ?9.31 mm/s at 78 K. Temperature dependent {sup 151}Eu data show first magnetic hyperfine field splitting at 25 K and a saturated magnetization of 17 T at 5.2 K. The temperature dependence can be described by an S=7/2 Brillouin function. - Graphical abstract: The near neighbor coordination of the strontium and europium atoms in SrAg{sub 1.12}Zn{sub 0.88}, EuAg{sub 1.17}Zn{sub 0.83}, and EuAuZn. - Highlights: • Synthesis of new intermetallic zinc compounds SrAgZn and EuAgZn. • Ferromagnetic ordering of EuAgZn at 29 K. • Magnetic hyperfine field splitting in the {sup 151}Eu Mössbauer spectrum.

  19. SSC v s . Hg at 0 -150,000 c fs SSC vs. Hg at 150,000 -370,000 cfs

    E-Print Network [OSTI]

    SSC v s . Hg at 0 - 150,000 c fs SSC vs. Hg at 150,000 - 370,000 cfs 0 20 40 60 80 0 20 40 60 80 0 (cfs) (Figure 1 ). The Bypass serves as flood protection for the City of Sacramento and conveys

  20. Changes in Zn speciation during soil formation from Zn-rich Olivier Jacquat a

    E-Print Network [OSTI]

    -containing calcite (at site Dornach), Zn-containing goethite (Gurnigel) and Zn-containing goethite and sphalerite contained substantial amounts of Zn-containing goethite ($50%) stemming from the parent rock, smaller in recalcitrant extraction steps, confirming that Zn-HIV, Zn-containing kaolinite and Zn-containing goethite

  1. Apparatus for growing HgI.sub.2 crystals

    DOE Patents [OSTI]

    Schieber, Michael M. (Jerusalem, IL); Beinglass, Israel (Jerusalem, IL); Dishon, Giora (Jerusalem, IL)

    1978-01-01

    A method and horizontal furnace for vapor phase growth of HgI.sub.2 crystals which utilizes controlled axial and radial airflow to maintain the desired temperature gradients. The ampoule containing the source material is rotated while axial and radial air tubes are moved in opposite directions during crystal growth to maintain a desired distance and associated temperature gradient with respect to the growing crystal, whereby the crystal interface can advance in all directions, i.e., radial and axial according to the crystallographic structure of the crystal. Crystals grown by this method are particularly applicable for use as room-temperature nuclear radiation detectors.

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

    E-Print Network [OSTI]

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

    2008-01-01

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

  3. Electronegativity calculation of bulk modulus and band gap of ternary ZnO-based alloys

    SciTech Connect (OSTI)

    Li, Keyan; Kang, Congying [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)] [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Xue, Dongfeng, E-mail: dongfeng@ciac.jl.cn [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China) [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-10-15

    In this work, the bulk moduli and band gaps of M{sub x}Zn{sub 1?x}O (M = Be, Mg, Ca, Cd) alloys in the whole composition range were quantitatively calculated by using the electronegativity-related models for bulk modulus and band gap, respectively. We found that the change trends of bulk modulus and band gap with an increase of M concentration x are same for Be{sub x}Zn{sub 1?x}O and Cd{sub x}Zn{sub 1?x}O, while the change trends are reverse for Mg{sub x}Zn{sub 1?x}O and Ca{sub x}Zn{sub 1?x}O. It was revealed that the bulk modulus is related to the valence electron density of atoms whereas the band gap is strongly influenced by the detailed chemical bonding behaviors of constituent atoms. The current work provides us a useful guide to compositionally design advanced alloy materials with both good mechanical and optoelectronic properties.

  4. SYNTHESIS AND SURFACE CHEMISTRY OF ZN3P2 Gregory M. Kimball, Nathan S. Lewis, Harry A. Atwater

    E-Print Network [OSTI]

    Kimball, Gregory

    alternative to traditional materials (e.g. CIGS, CdTe, a-Si) for thin film photovoltaics. Open circuit voltage in Zn3P2 cells has been limited by Fermi-level pinning due to surfaces states and heterojunction promise for solar energy conversion but has not been investigated as thoroughly as other thin film

  5. DISTORTIONS TO CURRENT-VOLTAGE CURVES OF CIGS CELLS WITH SPUTTERED Zn(O,S) BUFFER LAYERS

    E-Print Network [OSTI]

    Sites, James R.

    alternative to CdS for (CIGS) thin-film solar cells' buffer layer. It has a higher band gap and thus allows to current- voltage (J-V) curves of sputtered-Zn(O,S)/CIGS solar cells. A straightforward photodiode model partner in the CIGS team, and Russell for showing me the solar cells characterization, and John, Jen

  6. CD Label and Package Templates

    Broader source: Energy.gov [DOE]

    The Office of Energy Efficiency and Renewable Energy (EERE) has developed templates for CD labels and CD packages. These can be used for all EERE products. Both templates are available as EPS files, which can be downloaded and edited in a graphics package like Adobe Illustrator.

  7. Influence of CdTe thickness on structural and electrical properties of CdTe/CdS solar cells

    E-Print Network [OSTI]

    Romeo, Alessandro

    Influence of CdTe thickness on structural and electrical properties of CdTe/CdS solar cells A a b s t r a c ta r t i c l e i n f o Available online xxxx Keywords: Solar cells CdCl2 CdTe Thin absorbers Due to its high scalability and low production cost, CdTe solar cells have shown a very strong

  8. Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    1 Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells, Setagaya-ku, Tokyo 157-8572, Japan (Received ) KEYWORDS: ZnS buffer, Cu(In,Ga)Se2, thin-film solar cells alternative to CdS in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency

  9. Isoscalar multipole strength in Cd-110 and Cd-116 

    E-Print Network [OSTI]

    Lui, YW; Youngblood, David H.; Tokimoto, Y.; Clark, HL; John, B.

    2004-01-01

    multipole strength in 110Cd and 116Cd Y.-W. Lui, D. H. Youngblood, Y. Tokimoto, H. L. Clark, and B. John* Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA (Received 6 October 2003; published 24 March 2004) The giant resonance.... The statistical errors are smaller than the data points. LUI, YOUNGBLOOD, TOKIMOTO, CLARK, AND JOHN PHYSICAL REVIEW C 69, 034611 (2004) 034611-2 FIG. 3. Strength distributions obtained for 110Cd are shown by the histograms. Error bars represent the uncertainty...

  10. Author's personal copy Wading bird guano contributes to Hg accumulation in tree island soils

    E-Print Network [OSTI]

    Ma, Lena

    . The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those Everglades typically consists of head, middle and tail re- gions (Mason and Valk, 2002). The head is the most

  11. Nested reactor chamber and operation for Hg-196 isotope separation process

    DOE Patents [OSTI]

    Grossman, M.W.

    1991-10-08

    The present invention is directed to an apparatus for use in [sup 196]Hg separation and its method of operation. Specifically, the present invention is directed to a nested reactor chamber useful for [sup 196]Hg isotope separation reactions avoiding the photon starved condition commonly encountered in coaxial reactor systems. 6 figures.

  12. IDS120j WITHOUT RESISTIVE MAGNETS MODIFYING Hg MODULE ( NEW SH#1 REGION )

    E-Print Network [OSTI]

    McDonald, Kirk

    CRYO#1 WAS DECIDED DURING 11 / 15 / 2012 TARGET MEETING AND AN EXTENSION OF THE Hg POOL UPSTREAM UP cm. # RESULTS FROM SIMULATIONS WITH MODIFIED Hg POOL AND SH#1 REGION ( SC#1+2, SC#4 SEGMENTATION;IDS120j: GENERAL OVERVIEW (LEFT), POOL REGION DETAILS (RIGHT). [20 cm GAPS] SH#1 SH#1 SH#1A SH#2 SH#1A

  13. Disentangling the nuclear shape coexistence in even-even Hg isotopes using the interacting boson model

    E-Print Network [OSTI]

    J. E. García-Ramos; K. Heyde

    2014-10-10

    We intend to provide a consistent description of the even-even Hg isotopes, 172-200Hg, using the interacting boson model including configuration mixing. We pay special attention to the description of the shape of the nuclei and to its connection with the shape coexistence phenomenon.

  14. INELASTIC NEUTRON SCATTERING SELECTION RULES OF 03B1 HgI2 M. SIESKIND

    E-Print Network [OSTI]

    Boyer, Edmond

    899 INELASTIC NEUTRON SCATTERING SELECTION RULES OF 03B1 HgI2 M. SIESKIND Laboratoire de The inelastic neutron scattering selection rules of 03B1 HgI2 in the directions 0394, 03A3 and 039B are derived Abstracts 63.20D Introduction. - Inelastic neutron scattering is a powerful technique for the determination

  15. Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell interfaces and implications for improving performance

    E-Print Network [OSTI]

    Goddard III, William A.

    Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell (2014) Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell ZnO sputtering on the performance of Cu(In,Ga)Se2 thin film solar cells Appl. Phys. Lett. 105, 083906

  16. Blue and green electroluminescence from CdSe nanocrystal quantum-dot-quantum-wells

    SciTech Connect (OSTI)

    Lu, Y. F.; Cao, X. A.

    2014-11-17

    CdS/CdSe/ZnS quantum dot quantum well (QDQW) nanocrystals were synthesized using the successive ion layer adsorption and reaction technique, and their optical properties were tuned by bandgap and strain engineering. 3-monolayer (ML) CdSe QWs emitted blue photoluminescence at 467?nm with a spectral full-width-at-half-maximum of ?30?nm. With a 3 ML ZnS cladding layer, which also acts as a passivating and strain-compensating layer, the QDQWs acquired a ?35% quantum yield of the QW emission. Blue and green electroluminescence (EL) was obtained from QDQW light-emitting devices with 3–4.5 ML CdSe QWs. It was found that as the peak blueshifted, the overall EL was increasingly dominated by defect state emission due to poor hole injection into the QDQWs. The weak EL was also attributed to strong field-induced charge separation resulting from the unique QDQW geometry, weakening the oscillator strength of optical transitions.

  17. Simulation of Electric Field in Semi Insulating Au/CdTe/Au Detector under Flux

    SciTech Connect (OSTI)

    Franc, J.; James, R.; Grill, R.; Kubat, J.; Belas, E.; Hoschl, P.; Moravec, P.; Praus, P.

    2009-08-02

    We report our simulations on the profile of the electric field in semi insulating CdTe and CdZnTe with Au contacts under radiation flux. The type of the space charge and electric field distribution in the Au/CdTe/Au structure is at high fluxes result of a combined influence of charge formed due to band bending at the electrodes and from photo generated carriers, which are trapped at deep levels. Simultaneous solution of drift-diffusion and Poisson equations is used for the calculation. We show, that the space charge originating from trapped photo-carriers starts to dominate at fluxes 10{sup 15}-10{sup 16}cm{sup -2}s{sup -1}, when the influence of contacts starts to be negligible.

  18. Saving work to a CD-RW using the Optical CD Drive (CD Burner) Saving files to a Rewritable CD (or CD-RW) is very similar to the process described

    E-Print Network [OSTI]

    Machel, Hans

    Saving work to a CD-RW using the Optical CD Drive (CD Burner) Saving files to a Rewritable CD (or CD-RW) is very similar to the process described above for saving files to a Recordable CD (or CD to accept files again, so drag-and-drop the files that are on the desktop that you wish to save and when you

  19. Photochemistry of HgBr2 in methanol investigated using time-resolved X-ray liquidography

    E-Print Network [OSTI]

    Ihee, Hyotcherl

    , the photodissociation of HgX2 in the gas phase has been the subject of many spectroscopic and theoretical studies-body dissociation of HgI2 - HgI + I along reaction coordinates consisting of two vibrational modes.16,17 Moreover with the potential applications in blue-green laser system.22,23 Photodissociation of HgX2 induces the formation

  20. IDS120j: NO RESISTIVE MAGNETS / NEW Hg MODULE AZIMUTHAL DEPOSITED POWER STUDIES FOR SC#10-SC#12

    E-Print Network [OSTI]

    McDonald, Kirk

    SECTIONS WITH DETAILS OF Hg POOL MODULE FROM VAN GRAVE'S PRESENTATION ( 8 / 9 / 2012 ). THE DESIGN REQUIRES A 2.5 cm ! GAP BETWEEN SH#1 INNER VESSEL AND Hg POOL MODULE OUTER VESSEL. AN EVEN LARGER SPACE APPEARS TO BE BETWEEN INNER AND OUTER VESSEL OF THE Hg POOL MODULE FOR THE FLOW OF He GAS FOR COOLING THE POOL

  1. IDS120j WITHOUT RESISTIVE MAGNETS: NEW Hg MODULE mars1510: OFF VS. ON LAQGSM MODE SIMULATIONS

    E-Print Network [OSTI]

    McDonald, Kirk

    5E4 EVENTS ] #12;3 IDS120j: yz CROSS SECTIONS WITH DETAILS OF Hg POOL MODULE FROM VAN GRAVE'S PRESENTATION ( 8 / 9 / 2012 ). THE DESIGN REQUIRES A 2.5 cm ! GAP BETWEEN SH#1 INNER VESSEL AND Hg POOL MODULE OUTER VESSEL. AN EVEN LARGER SPACE APPEARS TO BE BETWEEN INNER AND OUTER VESSEL OF THE Hg POOL MODULE

  2. IDS120h GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING (P12 'POINT') WITH

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120h GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING (P12 'POINT POWER DISTRIBUTION. Nicholas Souchlas, PBL (1/24/2012) 1 #12;IDS120hm: (m IS FOR) modified Hg pool 'POINT'). >GAUSSIAN PROFILE: x = y = 0.12 cm. 2 #12;3 IDS120hm GEOMETRY = IDS120h WITH MODIFIED Hg POOL

  3. Development of Substrate Structure CdTe Photovoltaic Devices with Performance Exceeding 10%: Preprint

    SciTech Connect (OSTI)

    Dhere, R. G.; Duenow, J. N.; DeHart, C. M.; Li, J. V.; Kuciauskas, D.; Gessert, T. A.

    2012-08-01

    Most work on CdTe-based solar cells has focused on devices with a superstrate structure. This focus is due to the early success of the superstrate structure in producing high-efficiency cells, problems of suitable ohmic contacts for lightly doped CdTe, and the simplicity of the structure for manufacturing. The development of the CdCl2 heat treatment boosted CdTe technology and perpetuated the use of the superstrate structure. However, despite the beneficial attributes of the superstrate structure, devices with a substrate structure are attractive both commercially and scientifically. The substrate structure eliminates the need for transparent superstrates and thus allows the use of flexible metal and possibly plastic substrates. From a scientific perspective, it allows better control in forming the junction and direct access to the junction for detailed analysis. Research on such devices has been limited. The efficiency of these devices has been limited to around 8% due to low open-circuit voltage (Voc) and fill factor. In this paper, we present our recent device development efforts at NREL on substrate-structure CdTe devices. We have found that processing parameters required to fabricate high-efficiency substrate CdTe PV devices differ from those necessary for traditional superstrate CdTe devices. We have worked on a variety of contact materials including Cu-doped ZnTe and CuxTe. We will present a comparative analysis of the performance of these contacts. In addition, we have studied the influence of fabrication parameters on junction properties. We will present an overview of our development work, which has led to CdTe devices with Voc values of more than 860 mV and NREL-confirmed efficiencies approaching 11%.

  4. A CD19/Fc fusion protein for detection of anti-CD19 chimeric antigen receptors.

    E-Print Network [OSTI]

    De Oliveira, Satiro N; Wang, Jiexin; Ryan, Christine; Morrison, Sherie L; Kohn, Donald B; Hollis, Roger P

    2013-01-01

    Oliveira et al. : A CD19/Fc fusion protein for detection ofof the CD19-IgG 1 Fc fusion was performed under denatur- ingOpen Access A CD19/Fc fusion protein for detection of anti-

  5. A CD19/Fc fusion protein for detection of anti-CD19 chimeric antigen receptors

    E-Print Network [OSTI]

    De Oliveira, Satiro N; Wang, Jiexin; Ryan, Christine; Morrison, Sherie L; Kohn, Donald B; Hollis, Roger P

    2013-01-01

    Oliveira et al. : A CD19/Fc fusion protein for detection ofof the CD19-IgG 1 Fc fusion was performed under denatur- ingOpen Access A CD19/Fc fusion protein for detection of anti-

  6. Enhancement of photoluminescence in ZnS/ZnO quantum dots interfacial heterostructures

    SciTech Connect (OSTI)

    Rajalakshmi, M.; Sohila, S.; Ramesh, R.; Bhalerao, G.M.

    2012-09-15

    Highlights: ? ZnS/ZnO quantum dots (QDs) were synthesized by controlled oxidation of ZnS nanoparticles. ? Interfacial heterostructure formation of ZnS/ZnO QDs is seen in HRTEM. ? Enormous enhancement of UV emission (?10 times) in ZnS/ZnO QDs heterostructure is observed. ? Phonon confinement effect is seen in the Raman spectrum. -- Abstract: ZnS/ZnO quantum dots (QDs) were synthesized by controlled oxidation of ZnS nanoparticles. HRTEM image showed small nanocrystals of size 4 nm and the magnified image of single quantum dot shows interfacial heterostructure formation. The optical absorption spectrum shows a blue shift of 0.19 and 0.23 eV for ZnO and ZnS QDs, respectively. This is due to the confinement of charge carries within the nanostructures. Enormous enhancement in UV emission (10 times) is reported which is attributed to interfacial heterostructure formation. Raman spectrum shows phonons of wurtzite ZnS and ZnO. Phonon confinement effect is seen in the Raman spectrum wherein LO phonon peaks of ZnS and ZnO are shifted towards lower wavenumber side and are broadened.

  7. Toward ZnO Light Emitting Diode

    E-Print Network [OSTI]

    Liu, Jianlin

    2008-01-01

    applications such as light emitting diodes (LEDs) and laser009 "Toward ZnO Light Emitting Diode" Jianlin Liu July 2008Title: “Toward ZnO Light Emitting Diode” Sponsor: UC Energy

  8. Shape coexistence in {sup 180}Hg studied through the {beta} decay of {sup 180}Tl

    SciTech Connect (OSTI)

    Elseviers, J.; Bree, N.; Diriken, J.; Huyse, M.; Ivanov, O.; Van den Bergh, P.; Van Duppen, P.; Andreyev, A. N.; Antalic, S.; Barzakh, A.; Fedorov, D.; Cocolios, T. E.; Seliverstov, M.; Comas, V. F.; Heredia, J. A.; Fedosseyev, V. N.; Marsh, B. A.; Franchoo, S.; Page, R. D.

    2011-09-15

    The {beta}{sup +}/EC decay of {sup 180}Tl and excited states in the daughter nucleus {sup 180}Hg have been investigated at the CERN On-Line Isotope Mass Separator (ISOLDE) facility. Many new low-lying energy levels were observed in {sup 180}Hg, of which the most significant are the 0{sub 2}{sup +} at 419.6 keV and the 2{sub 2}{sup +} at 601.3 keV. The former is the bandhead of an excited band in {sup 180}Hg assumed originally to be of prolate nature. From the {beta} feeding to the different states in {sup 180}Hg, the ground-state spin of {sup 180}Tl was deduced to be (4{sup -},5{sup -}).

  9. Results of Hg speciation testing on tanks 30, 32, and 37 surface samples

    SciTech Connect (OSTI)

    Bannochie, C. J.

    2015-11-11

    The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team.

  10. Patterned three-color ZnCdSeZnCdMgSe quantum-well structures for integrated full-color and white light emitters

    E-Print Network [OSTI]

    . This result demonstrates the feasibility of fabricating integrated full-color light emitting diode and laser American Institute of Physics. S0003-6951 00 04149-8 Light emitting diodes LEDs and laser diodes LDs having

  11. A CD19/Fc fusion protein for detection of anti-CD19 chimeric antigen receptors.

    E-Print Network [OSTI]

    De Oliveira, Satiro N; Wang, Jiexin; Ryan, Christine; Morrison, Sherie L; Kohn, Donald B; Hollis, Roger P

    2013-01-01

    blocking experiments were performed using anti-human CD19series of experiments. The exons 2 and 4 of the human CD19

  12. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for

    Office of Scientific and Technical Information (OSTI)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech ConnectSpeeding accessusers'

  13. Quantification and Modeling of Tripartite CD2-, CD58FC Chimera (Alefacept)-, and CD16-mediated Cell Adhesion*

    E-Print Network [OSTI]

    Vale, Ronald D.

    Adhesion* Received for publication,July 9, 2007, and in revised form, September 21, 2007 Published, JBC with human IgG1 Fc. Alefacept mediates adhesion by bridging CD2 on T cells to activating Fc receptors killing by NK cells and adhesion between CD2- and CD16-expressing cells at an optimum concentration of 100

  14. Preparation of new morphological ZnO and Ce-doped ZnO

    SciTech Connect (OSTI)

    Chelouche, A.; Djouadi, D.; Aksas, A. [Laboratoire de Génie de l'Environnement, Université A. Mira de Béjaia, Route de Targua Ouzemmour Béjaia (Algeria)

    2013-12-16

    ZnO micro-tori and cerium doped hexangulars ZnO have been prepared by the sol-gel method under methanol hypercritical conditions of temperature and pressure. X-ray diffraction (XRD) measurement has revealed the high crystalline quality and the nanometric size of the samples. Scanning electron microscopy (SEM) has shown that the ZnO powder has a torus-like shape while that of ZnO:Ce has a hexangular-like shape, either standing free or inserted into the cores of ZnO tori. Transmission electron microscopy (TEM) has revealed that the ZnO particles have sizes between 25 and 30 nm while Ce-doped ZnO grains have diameters ranging from 75 nm to 100 nm. Photoluminescence spectra at room temperature of the samples have revealed that the introduction of cerium in ZnO reduces the emission intensity lines, particularly the ZnO red and green ones.

  15. Photodeposition of Pt on Colloidal CdS and CdSe/CdS Semiconductor Nanostructures

    SciTech Connect (OSTI)

    Dukovic, Gordana; Merkle, Maxwell G.; Nelson, James H.; Hughes, Steven M.; Alivisatos, A. Paul

    2008-08-06

    Semiconductor photocatalysis has been identified as a promising avenue for the conversion of solar energy into environmentally friendly fuels, most notably by the production of hydrogen from water.[1-5] Nanometer-scale materials in particular have attracted considerable scientific attention as the building blocks for light-harvesting applications.[6,7] Their desirable attributes include tunability of the optical properties with size, amenability to relatively inexpensive low-temperature processing, and a high degree of synthetic sophistication leading to increasingly complex and multi-functional architectures. For photocatalysis in particular, the high surface-to-volume ratios in nanoscale materials should lead to an increased availability of carriers for redox reactions on the nanoparticle surface. Recombination of photoexcited carriers directly competes with photocatalytic activity.[3] Charge separation is often achieved with multi-component heterostructures. An early example is the case of TiO2 powders functionalized with Pt and RuO2 particles, where photoexcited electrons are transferred to Pt (the reduction site) and holes to RuO2 (the oxidation site).[8] More recently, many colloidally synthesized nanometer-scale metal-semiconductor heterostructures have been reported.[7,9,10] A majority of these structures are made by thermal methods.[7,10] We have chosen to study photochemical formation of metal-semiconductor heterostructures. The detailed understanding of the mechanisms involved in photodeposition of metals on nanometer-scale semiconductors is necessary to enable a high degree of synthetic control. At the same time, because the results of metal deposition can be directly observed by electron microscopy, it can be used to understand how factors such as nanocrystal composition, shape, carrier dynamics, and surface chemistry influence the photochemical properties of semiconductor nanocrystals. In this communication, we report on the photodeposition of Pt on colloidal CdS and CdSe/CdS core/shell nanocrystals. Among the II-VI semiconductors, CdS is of particular interest because it has the correct band alignment for water photolysis[2] and has been demonstrated to be photocatalytically active.[11-16] We have found that the photoexcitation of CdS and CdSe/CdS in the presence of an organometallic Pt precursor leads to deposition of Pt nanoparticles on the semiconductor surface. Stark differences are observed in the Pt nanoparticle location on the two substrates, and the photodeposition can be completely inhibited by the modification of the semiconductor surface. Our results suggest that tuning of the semiconductor band structure, spatial organization and surface chemistry should be crucial in the design of photocatalytic nanostructures.

  16. In-beam conversion-electron spectroscopy of {sup 180}Hg

    SciTech Connect (OSTI)

    Page, R. D.; Wiseman, D. R.; Butler, P. A.; Herzberg, R.-D.; Jones, G. D.; Joss, D. T.; Keenan, A.; Rainovski, G. I.; Andreyev, A. N.; Grahn, T.; Greenlees, P. T.; Jones, P. M.; Julin, R.; Juutinen, S.; Kankaanpaeae, H.; Kettunen, H.; Kuusiniemi, P.; Leino, M.; Muikku, M.; Nieminen, P.

    2011-09-15

    Excited states in {sup 180}Hg were populated using the {sup 147}Sm({sup 36}Ar,3n){sup 180}Hg reaction and studied by in-beam conversion-electron spectroscopy. Conversion electrons emitted at the target position were measured using the Silicon Array for Conversion Electron Detection (SACRED) spectrometer and tagged through the characteristic {alpha} decays of {sup 180}Hg detected in a position-sensitive silicon strip detector located at the focal plane of the gas-filled recoil separator Recoil Ion Transport Unit (RITU). Electron conversion of transitions previously assigned to {sup 180}Hg through in-beam {gamma}-ray spectroscopy studies was identified up to the 10{sup +}{yields}8{sup +} transition and the intensities of the conversion-electron transitions were found to be consistent with the previous multipolarity assignments. Evidence was also found for two highly converted transitions in {sup 180}Hg: a 167 keV transition is interpreted as the transition from the newly identified 2{sub 2}{sup +} state at 601 keV to the 2{sub 1}{sup +} state at 434 keV, while a 420 keV transition is assigned as the E0 decay from the 0{sup +} bandhead of the prolate-deformed configuration to the weakly deformed ground state.

  17. Cytotoxicity of InP/ZnS quantum dots related to reactive oxygen species generation.

    SciTech Connect (OSTI)

    Chibli, H.; Carlini, L.; Park, S.; Dimitrijevic, N. M.; Nadeau, J. L.

    2011-01-01

    Indium phosphide (InP) quantum dots (QDs) have emerged as a presumably less hazardous alternative to cadmium-based particles, but their cytotoxicity has not been well examined. Although their constituent elements are of very low toxicity to cells in culture, they nonetheless exhibit phototoxicity related to generation of reactive oxygen species by excited electrons and/or holes interacting with water and molecular oxygen. Using spin-trap electron paramagnetic resonance (EPR) spectroscopy and reporter assays, we find a considerable amount of superoxide and a small amount of hydroxyl radical formed under visible illumination of biocompatible InP QDs with a single ZnS shell, comparable to what is seen with CdTe. A double thickness shell reduces the reactive oxygen species concentration approximately two-fold. Survival assays in five cell lines correspondingly indicate a distinct reduction in toxicity with the double-shell InP QDs. Toxicity varies significantly across cell lines according to the efficiency of uptake, being overall significantly less than what is seen with CdTe or CdSe/ZnS. This indicates that InP QDs are a useful alternative to cadmium-containing QDs, while remaining capable of electron-transfer processes that may be undesirable or which may be exploited for photosensitization applications.

  18. IDS120j WITHOUT RESISTIVE MAGNETS: NEW Hg MODULE MARS1510 ( DESKTOP ) vs. MARS1512 ( PRINCETON CLUSTER )

    E-Print Network [OSTI]

    McDonald, Kirk

    500,000 / 5,000,000 2 #12;3 IDS120j: yz CROSS SECTIONS WITH DETAILS OF Hg POOL MODULE FROM VAN GRAVE'S PRESENTATION ( 8 / 9 / 2012 ). THE DESIGN REQUIRES A 2.5 cm ! GAP BETWEEN SH#1 INNER VESSEL AND Hg POOL MODULE OUTER VESSEL. AN EVEN LARGER SPACE APPEARS TO BE BETWEEN INNER AND OUTER VESSEL OF THE Hg POOL MODULE

  19. IDS120j WITHOUT RESISTIVE MAGNETS: NEW Hg MODULE mars1510 ( DESKTOP ) vs. mars1512 ( PRINCETON CLUSTER )

    E-Print Network [OSTI]

    McDonald, Kirk

    500,000 / 5,000,000 20,000,000 2 #12;3 IDS120j: yz CROSS SECTIONS WITH DETAILS OF Hg POOL MODULE FROM VESSEL AND Hg POOL MODULE OUTER VESSEL. AN EVEN LARGER SPACE APPEARS TO BE BETWEEN INNER AND OUTER VESSEL OF THE Hg POOL MODULE FOR THE FLOW OF He GAS FOR COOLING THE POOL. THE RADIUS OF THE UPPER HALF SEMICIRCULAR

  20. IDS120h GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING (P12 'POINT')

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120h GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING (P12 'POINT (12/27/2011) 1 #12;IDS120hm: (m IS FOR) modified Hg pool vessel IN IDS120h. # 5E5 SIMULATIONS AND SHIFTED Be WIDOW FROM 600 cm (0.6 cm THICK) TO 300 cm (1 cm THICK). MODIFIED Hg POOL EXTENTS FROM 86 cm

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

    SciTech Connect (OSTI)

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

    2014-02-03

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

  2. HIGH EFFICIENCY CdTe/CdS THIN FILM SOLAR CELLS WITH A NOVEL BACK-CONTACT Nicola Romeoa

    E-Print Network [OSTI]

    Romeo, Alessandro

    HIGH EFFICIENCY CdTe/CdS THIN FILM SOLAR CELLS WITH A NOVEL BACK-CONTACT Nicola Romeoa , Alessio in the fabrication of high efficiency CdTe/CdS thin film solar cells. Usually, it is done first by etching the CdTe/CdS structure causing shunt paths by segregating into the grain boundaries or lowering the cell efficiency

  3. Synthesis and structural characterization of ZnTe/ZnSe core/shell tunable quantum dots

    E-Print Network [OSTI]

    Guan, Juan

    2008-01-01

    Colloidal semiconductor nanocrystals or quantum dots have attracted much attention recently with their unique optical properties. Here we present a novel approach to synthesize ZnTe/ZnSe core/shell tunable quantum dots. ...

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

    DOE Patents [OSTI]

    Bhattacharya, Raghu N. (Littleton, CO)

    2009-11-03

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

  5. Local coordination of Zn in hydroxy-interlayered minerals and implications for Zn retention in soils

    E-Print Network [OSTI]

    in soils Olivier Jacquat, Andreas Voegelin *, Ruben Kretzschmar Institute of Biogeochemistry and Pollutant-interlayered minerals (HIM) for Zn retention in contaminated soils. Published and newly collected extended X. In a second part, we determined the spe- ciation of Zn in eight contaminated soils (251­1039 mg/kg Zn

  6. CD

    Gasoline and Diesel Fuel Update (EIA)

    and 1983 levels. The mean floorspace per building for all commercial buildings in the United States was 14,000 square feet, while the median was 5,000 square feet. This...

  7. CD

    Gasoline and Diesel Fuel Update (EIA)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979Coal4 Arizona - NaturalYear1 U.S.End-Use Equipmentm 3 (D

  8. SmartHG: Energy Demand Aware Open Services for Smart Grid Intelligent Automation

    E-Print Network [OSTI]

    Tronci, Enrico

    : to minimise energy usage and cost for each home, and to support the Distribution Network Operator (DNO) in optimising operation of the Electric Distribution Network (EDN). SmartHG goals are achieved solar panels)], for each time slot (say each hour) the DNO price policy defines an interval of energy

  9. IDS120h POWER DEPOSITION AND Hg POOL STUDIES Nicholas Souchlas (7/26/2011)

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120h POWER DEPOSITION AND Hg POOL STUDIES Nicholas Souchlas (7/26/2011) 1 #12;Power deposition;ENERGY DEPOSITED IN SC SOLENOIDS (SC#), SHIELDING (SH#). P12 OPTIMIZED POINT, POOL WALL CASES x=+/-6W DECREASE IN DP (BLUE AREA) SH#4~ SMALL INCREASE IN DP (YELLOW AREA) RS, BP~ SAME DP #12;HIGHLIGHTS : Power

  10. Application of tree rings [dendrochemistry] for detecting historical trends in air Hg concentrations across multiple

    E-Print Network [OSTI]

    Weisberg, Peter J.

    ). Additional sources include cement production, oil and ore processing, mining (lead, zinc, pig iron, steel to millennia) at time steps of B5 years. Keywords Pinus Á National Park Á Proxy for air pollution Á Mining, artisanal mining and coal combus- tion are considered the two major sources of Hg emissions (UNEP 2013

  11. Recycling of CdTe photovoltaic waste

    DOE Patents [OSTI]

    Goozner, Robert E. (Charlotte, NC); Long, Mark O. (Charlotte, NC); Drinkard, Jr., William F. (Charlotte, NC)

    1999-01-01

    A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate and electrolyzing the leachate to separate Cd from Te, wherein the Te is deposits onto a cathode while the Cd remains in solution.

  12. Gate-Defined Wires in HgTe Quantum Wells: From Majorana Fermions to Spintronics Johannes Reuther and Jason Alicea

    E-Print Network [OSTI]

    Yacoby, Amir

    Gate-Defined Wires in HgTe Quantum Wells: From Majorana Fermions to Spintronics Johannes Reuther and various spintronics applications based on gate-defined wires in HgTe quantum wells. Because of the Dirac­15] architectures, while not usually viewed from a spintronics lens, similarly rely crucially on spin manipulation

  13. WPN 10-3: Procurement Toolkit CD

    Office of Energy Efficiency and Renewable Energy (EERE)

    To issue the Procurement Toolkit CD to all Grantees, to share with their local agencies, for use in the Weatherization Assistance Program.

  14. Resonant nonradiative energy transfer in CdSe/ZnS core/shell nanocrystal solids enhances

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    to recycle trapped excitons into nanocrystals using nonradiative energy transfer. We present the time of nanocrystals and conjugated polymers," New J. Phys. 9, 362 (2007). #97387 - $15.00 USD Received 12 Jun 2008

  15. Lateral redistribution of excitons in CdSeZnSe quantum dots M. Strassburg,a)

    E-Print Network [OSTI]

    Nabben, Reinhard

    of quantum dot QD structures strongly depends on the growth conditions and the material system. Pronounced- neously QD ensemble we chose a system with well-known optical and structural properties.13­15 A single formed in a Stranski­Krastanow-like mode pro- vide for 3D confinement, i.e., QD states. Despite

  16. CdO-CdS nano-composites as improved photo-catalysts for the generation of hydrogen from water

    SciTech Connect (OSTI)

    Kahane, Shital V.; Mahamuni, Shailaja; Sasikala, R.; Sudarsan, V.

    2014-04-24

    CdO-CdS nanocomposites were prepared by polyol method followed by heating at 300°C. XRD study confirmed the atomic scale mixing of CdO and CdS nanoparticles, leading to the formation of CdSO{sub 3} phase at the interfacial region between CdO and CdS. The enhancement in photo-catalytic activity for hydrogen generation from water is observed in case of CdO-CdS nanocomposites compared to individual CdS and CdO nanoparticles. Based on XRD, steady state and time resolved luminescence studies and surface area measurements, it is determined that, the fine mixing of CdS and CdO, higher surface area of the composite sample and increase in lifetime of the charge carriers are responsible for the observed increase in hydrogen yield from water when composite sample was used as the photo-catalyst compared to individual components.

  17. Luminal Bacteria Recruit CD103+ Dendritic Cells

    E-Print Network [OSTI]

    Immunity Article Luminal Bacteria Recruit CD103+ Dendritic Cells into the Intestinal Epithelium@weizmann.ac.il http://dx.doi.org/10.1016/j.immuni.2013.01.009 SUMMARY CD103+ dendritic cells (DCs) carry bacteria from bacteria or presenting bacterial antigens in mesen- tery lymph nodes. We used 2-photon microscopy in live

  18. CuIn1-xGaxS2 thin film solar cells with ZnxCd1-xS as heterojunction partner Bhaskar Kumar

    E-Print Network [OSTI]

    Sites, James R.

    CuIn1-xGaxS2 thin film solar cells with ZnxCd1-xS as heterojunction partner Bhaskar Kumar 1 , Parag 80523 ABSTRACT Copper indium gallium sulfide, CuIn1-xGaxS2 (CIGS2) solar cells prepared with chemical/heterojunction partner/ ZnO/Cr/Ag contact fingers solar cells of area ~0.44 cm 2 were fabricated at FSEC

  19. Fluorescent Sensors for Zn2+ Based on a Fluorescein Platform

    E-Print Network [OSTI]

    Tsien, Roger Y.

    Versity of California at San Diego, La Jolla, California 92093-0647 ReceiVed January 5, 2001 Abstract: Two new homologous Zn2+ transport proteins (ZnT-1, ZnT-2, and ZnT-3)11-13 and by metallothio- neins (MTs),14 properties § Massachusetts Institute of Technology. Department of Pharmacology, University of California

  20. Unique Challenges Accompany Thick-Shell CdSe/nCdS (n > 10) Nanocrystal Synthesis

    SciTech Connect (OSTI)

    Guo, Y; Marchuk, K; Abraham, R; Sampat, S; Abraham, R.; Fang, N; Malko, AV; Vela, J

    2011-12-23

    Thick-shell CdSe/nCdS (n {ge} 10) nanocrystals were recently reported that show remarkably suppressed fluorescence intermittency or 'blinking' at the single-particle level as well as slow rates of Auger decay. Unfortunately, whereas CdSe/nCdS nanocrystal synthesis is well-developed up to n {le} 6 CdS monolayers (MLs), reproducible syntheses for n {ge} 10 MLs are less understood. Known procedures sometimes result in homogeneous CdS nucleation instead of heterogeneous, epitaxial CdS nucleation on CdSe, leading to broad and multimodal particle size distributions. Critically, obtained core/shell sizes are often below those desired. This article describes synthetic conditions specific to thick-shell growth (n {ge} 10 and n {ge} 20 MLs) on both small (sub2 nm) and large (>4.5 nm) CdSe cores. We find added secondary amine and low concentration of CdSe cores and molecular precursors give desired core/shell sizes. Amine-induced, partial etching of CdSe cores results in apparent shell-thicknesses slightly beyond those desired, especially for very-thick shells (n {ge} 20 MLs). Thermal ripening and fast precursor injection lead to undesired homogeneous CdS nucleation and incomplete shell growth. Core/shells derived from small CdSe (1.9 nm) have longer PL lifetimes and more pronounced blinking at single-particle level compared with those derived from large CdSe (4.7 nm). We expect our new synthetic approach will lead to a larger throughput of these materials, increasing their availability for fundamental studies and applications.

  1. CdTe devices and method of manufacturing same

    DOE Patents [OSTI]

    Gessert, Timothy A.; Noufi, Rommel; Dhere, Ramesh G.; Albin, David S.; Barnes, Teresa; Burst, James; Duenow, Joel N.; Reese, Matthew

    2015-09-29

    A method of producing polycrystalline CdTe materials and devices that incorporate the polycrystalline CdTe materials are provided. In particular, a method of producing polycrystalline p-doped CdTe thin films for use in CdTe solar cells in which the CdTe thin films possess enhanced acceptor densities and minority carrier lifetimes, resulting in enhanced efficiency of the solar cells containing the CdTe material are provided.

  2. The impact of oxygen incorporation during intrinsic ZnO sputtering on the performance of Cu(In,Ga)Se{sub 2} thin film solar cells

    SciTech Connect (OSTI)

    Lee, Kkotnim; Ok, Eun-A; Park, Jong-Keuk; Kim, Won Mok; Baik, Young-Joon; Jeong, Jeung-hyun; Kim, Donghwan

    2014-08-25

    We investigated the impact of incorporating 2% oxygen during intrinsic ZnO sputtering on the efficiency of Cu(In,Ga)Se{sub 2} solar cells. The added oxygen not only reduced the optical absorption loss of the Al-doped ZnO overlaying layer but also improved the electronic properties of the underlying CdS/Cu(In,Ga)Se{sub 2} by increasing carrier density, lowering defect level, and increasing diffusion length, eventually enhancing J{sub SC}, V{sub OC}, and fill factor. It was found that the Na doping concentration was significantly increased around the CdS/Cu(In,Ga)Se{sub 2} junction due to the plasma-activated oxygen. The improved electronic properties are better explained by the increased Na concentration than simply the oxygen-related defect passivation.

  3. Axi-symmetrical flow reactor for [sup 196]Hg photochemical enrichment

    DOE Patents [OSTI]

    Grossman, M.W.

    1991-04-30

    The present invention is directed to an improved photochemical reactor useful for the isotopic enrichment of a predetermined isotope of mercury, especially, [sup 196]Hg. Specifically, two axi-symmetrical flow reactors were constructed according to the teachings of the present invention. These reactors improve the mixing of the reactants during the photochemical enrichment process, affording higher yields of the desired [sup 196]Hg product. Measurements of the variation of yield (Y) and enrichment factor (E) along the flow axis of these reactors indicates very substantial improvement in process uniformity compared to previously used photochemical reactor systems. In one preferred embodiment of the present invention, the photoreactor system was built such that the reactor chamber was removable from the system without disturbing the location of either the photochemical lamp or the filter employed therewith. 10 figures.

  4. Three very young HgMn stars in the Orion OB1 Association

    E-Print Network [OSTI]

    Vincent M. Woolf; David L. Lambert

    1999-05-18

    We report the detection of three mercury-manganese stars in the Orion OB1 association. HD 37886 and BD-0 984 are in the approximately 1.7 million year old Orion OB1b. HD 37492 is in the approximately 4.6 million year old Orion OB1c. Orion OB1b is now the youngest cluster with known HgMn star members. This places an observational upper limit on the time scale needed to produce the chemical peculiarities seen in mercury-manganese stars, which should help in the search for the cause or causes of the peculiar abundances in HgMn and other chemically peculiar upper main sequence stars.

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

    E-Print Network [OSTI]

    McCluskey, Matthew

    Optical transitions and multiphonon Raman scattering of Cu doped ZnO and MgZnO ceramics Jesse Huso doped ZnO and MgZnO ceramics were created via a process of cold pressing and annealing, and their optical properties and phonon dynamics were studied. It was found that the ceramics exhibit infrared

  6. Automated product recovery in a HG-196 photochemical isotope separation process

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA); Speer, Richard (Reading, MA)

    1992-01-01

    A method of removing deposited product from a photochemical reactor used in the enrichment of .sup.196 Hg has been developed and shown to be effective for rapid re-cycling of the reactor system. Unlike previous methods relatively low temperatures are used in a gas and vapor phase process of removal. Importantly, the recovery process is understood in a quantitative manner so that scaling design to larger capacity systems can be easily carried out.

  7. Automated product recovery in a Hg-196 photochemical isotope separation process

    DOE Patents [OSTI]

    Grossman, M.W.; Speer, R.

    1992-07-21

    A method of removing deposited product from a photochemical reactor used in the enrichment of [sup 196]Hg has been developed and shown to be effective for rapid re-cycling of the reactor system. Unlike previous methods relatively low temperatures are used in a gas and vapor phase process of removal. Importantly, the recovery process is understood in a quantitative manner so that scaling design to larger capacity systems can be easily carried out. 2 figs.

  8. Homogeneous and Heterogeneous Reaction and Transformation of Hg and Trace Metals in Combustion Systems

    SciTech Connect (OSTI)

    J. Helble; Clara Smith; David Miller

    2009-08-31

    The overall goal of this project was to produce a working dynamic model to predict the transformation and partitioning of trace metals resulting from combustion of a broad range of fuels. The information provided from this model will be instrumental in efforts to identify fuels and conditions that can be varied to reduce metal emissions. Through the course of this project, it was determined that mercury (Hg) and arsenic (As) would be the focus of the experimental investigation. Experiments were therefore conducted to examine homogeneous and heterogeneous mercury oxidation pathways, and to assess potential interactions between arsenic and calcium. As described in this report, results indicated that the role of SO{sub 2} on Hg oxidation was complex and depended upon overall gas phase chemistry, that iron oxide (hematite) particles contributed directly to heterogeneous Hg oxidation, and that As-Ca interactions occurred through both gas-solid and within-char reaction pathways. Modeling based on this study indicated that, depending upon coal type and fly ash particle size, vaporization-condensation, vaporization-surface reaction, and As-CaO in-char reaction all play a role in arsenic transformations under combustion conditions.

  9. Local Charge Neutrality Condition, Fermi Level, and Carrier Compensation of CdTe Polycrystalline Thin Film in CdS/CdTe Solar Cells

    E-Print Network [OSTI]

    Thin Film in CdS/CdTe Solar Cells Ken K. Chin1 and Su-Huai Wei 2 1 Department of Physics and Apollo Cd vacancies VCd (o/-) and VCd (-/2-) in CdTe thin film), the general formulation of charge neutrality-level and multi-configuration intrinsic/impurity defect states for understanding the performance of CdTe thin film

  10. Recycling of CdTe photovoltaic waste

    DOE Patents [OSTI]

    Goozner, Robert E. (Charlotte, NC); Long, Mark O. (Charlotte, NC); Drinkard, Jr., William F. (Charlotte, NC)

    1999-04-27

    A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the metals in dilute nitric acid, leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate, adding a calcium containing base to the leachate to precipitate Cd and Te, separating the precipitated Cd and Te from the leachate, and recovering the calcium-containing base.

  11. Recycling of CdTe photovoltaic waste

    DOE Patents [OSTI]

    Goozner, R.E.; Long, M.O.; Drinkard, W.F. Jr.

    1999-04-27

    A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the metals in dilute nitric acid, leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate, adding a calcium containing base to the leachate to precipitate Cd and Te, separating the precipitated Cd and Te from the leachate, and recovering the calcium-containing base. 3 figs.

  12. Junction Evolution During Fabrication of CdS/CdTe Thin-film PV Solar Cells (Presentation)

    SciTech Connect (OSTI)

    Gessert, T. A.

    2010-09-01

    Discussion of the formation of CdTe thin-film PV junctions and optimization of CdTe thin-film PV solar cells.

  13. Crystal structure and magnetic properties and Zn substitution effects on the spin-chain compound Sr{sub 3}Co{sub 2}O{sub 6}

    SciTech Connect (OSTI)

    Wang, Xia [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Guo, Yanfeng, E-mail: Yangfeng.Guo@physics.ox.ac.uk [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Sun, Ying [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [Materials Processing Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba Ibaraki 305-0047 (Japan); Matsushita, Yoshitaka [Materials Analysis Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba Ibaraki 305-0047 (Japan); Yamaura, Kazunari, E-mail: yamaura.kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan)

    2013-08-15

    The effects of substituting Co on the spin-chain compound Sr{sub 3}Co{sub 2}O{sub 6} with Zn were investigated by synchrotron X-ray diffraction, magnetic susceptibility, isothermal magnetization, and specific heat measurements. To the best of our knowledge, this is the first report to describe the successful substitution of Co in Sr{sub 3}Co{sub 2}O{sub 6} with Zn. The substitution was carried out by a method involving high pressures and temperatures to obtain Sr{sub 3}CoZnO{sub 6}, which crystalized into a K{sub 4}CdCl{sub 6}-derived rhombohedral structure with a space group of R-3c, similar to the host compound. With the Zn substitution, the Ising-type magnetic anisotropy of the host compound remarkably reduced; the newly formed Sr{sub 3}CoZnO{sub 6} became magnetically isotropic with Heisenberg-type characteristics. This could probably be ascribed to the establishment of a different interaction pathway, –Co{sup 4+}(S=1/2)–O–Zn{sup 2+}(S=0)–O–Co{sup 4+}(S=1/2)–. Details of the magnetic properties of Zn substituted Sr{sub 3}Co{sub 2}O{sub 6} were reported. - Graphical abstract: Crystal structure of the spin-chain compound Sr{sub 3}CoZnO{sub 6} synthesized at 6 GPa. Zn atoms preferably occupy the trigonal prism sites rather than the octahedral sites. As a result, the compound is much magnetically isotropic. Highlights: • Effects of substituting Co with Zn on spin-chain magnetism of Sr{sub 3}Co{sub 2}O{sub 6} were studied. • High-pressure synthesis resulted in a solid solution of Sr{sub 3}CoZnO{sub 6}. • Sr{sub 3}CoZnO{sub 6} showed more isotropic magnetism than the host Sr{sub 3}Co{sub 2}O{sub 6}.

  14. Measurements of Dynamic Characteristics of Hg Jet Stream 11/16/2005 by HeeJin Park, SUNY Stony Brook

    E-Print Network [OSTI]

    McDonald, Kirk

    Measurements of Dynamic Characteristics of Hg Jet Stream 11/16/2005 by HeeJin Park, SUNY Stony Brook Purpose : To measure velocity and distortion of jet stream and verify the hydro-dynamic phenomenon

  15. High-pressure dissociation of silver mercury iodide, Ag{sub 2}HgI{sub 4}

    SciTech Connect (OSTI)

    Parfitt, D.C. [Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom); Hull, S. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (United Kingdom)]. E-mail: s.hull@rl.ac.uk; Keen, D.A. [Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (United Kingdom); Crichton, W. [ESRF, 6 Rue Jules Horowitz, BP 220, 38043 Grenoble CEDEX 9 (France)

    2004-10-01

    High-pressure X-ray diffraction has been used to probe the behavior of the superionic conductor silver mercury iodide (Ag{sub 2}HgI{sub 4}) at pressures up to 5GPa and at temperatures from 295 to 370K. Significant changes in the diffraction spectra, indicative of structural transitions, are observed around 0.7 and 1.3GPa across the range of temperatures studied. The change at 0.7GPa is shown to correspond to the dissociation of silver mercury iodide into silver iodide and mercury iodide, i.e., Ag{sub 2}HgI{sub 4}->2AgI+HgI{sub 2}. The second transition, at 1.3GPa, is due to a structural phase transition within HgI{sub 2}. Rietveld analysis of the diffraction data is used to confirm and refine all the known crystal structures.

  16. Total and organic Hg concentrations in cephalopods from the North Eastern Atlantic waters: influence of geographical origin and feeding

    E-Print Network [OSTI]

    Boyer, Edmond

    %). With the exception of oceanic squids, the digestive gland globally displayed higher T-Hg concentrations than its toxicity as a result of its enhanced penetration through lipid membranes (Boudou et al. 1983

  17. Biokinetics of Hg and Pb accumulation in the encapsulated egg of the1 common cuttlefish Sepia officinalis: radiotracer experiments2

    E-Print Network [OSTI]

    Boyer, Edmond

    with the32 eggshell indicating that the latter acted as an efficient shield against metal penetration. From the Ocean (Cossa et al., 2002). Hg and Pb are also discharged in coastal waters due to the50 contaminated

  18. Trace metal contamination of waters, sediments, and organisms of the Swan Lake area of Galveston Bay 

    E-Print Network [OSTI]

    Park, Junesoo

    1995-01-01

    , mussel, snail, crab, fish, shrimp, and spartina) in the area. Sediments and organisms were analyzed for total Ag, Al, As, Cd, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, and Zn. Water samples were analyzed for Cd, Cu, Fe, Mn, and Sn. The variabilities and geographic...

  19. Ultrasensitive detection of Hg{sup 2+} using oligonucleotide-functionalized AlGaN/GaN high electron mobility transistor

    SciTech Connect (OSTI)

    Cheng, Junjie; Li, Jiadong; Miao, Bin; Wu, Dongmin; Wang, Jine; Pei, Renjun; Wu, Zhengyan

    2014-08-25

    An oligonucleotide-functionalized ion sensitive AlGaN/GaN high electron mobility transistor (HEMT) was fabricated to detect trace amounts of Hg{sup 2+}. The advantages of ion sensitive AlGaN/GaN HEMT and highly specific binding interaction between Hg{sup 2+} and thymines were combined. The current response of this Hg{sup 2+} ultrasensitive transistor was characterized. The current increased due to the accumulation of Hg{sup 2+} ions on the surface by the highly specific thymine-Hg{sup 2+}-thymine recognition. The dynamic linear range for Hg{sup 2+} detection has been determined in the concentrations from 10{sup ?14} to 10{sup ?8} M and a detection limit below 10{sup ?14} M level was estimated, which is the best result of AlGaN/GaN HEMT biosensors for Hg{sup 2+} detection till now.

  20. Photodisintegration of the isotope {sup 116}Cd

    SciTech Connect (OSTI)

    Belyshev, S. S.; Ishkhanov, B. S. [Moscow State University (Russian Federation)] [Moscow State University (Russian Federation); Orlin, V. N.; Stopani, K. A.; Khankin, V. V.; Shvedunov, N. V., E-mail: gg.swedn@gmail.com [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2013-08-15

    The results obtained by measuring the yields of photodisintegration of the isotope {sup 116}Cd irradiated with bremsstrahlung photons whose spectrum had an endpoint energy of 55 MeV are presented and compared with the results of theoretical calculations.

  1. C.D. Howe Institute Working Paper

    E-Print Network [OSTI]

    Government's 2006­2007 Greenhouse Gas Policies Mark Jaccard and Nic Rivers Inside... Current policy proposals Management, Simon Fraser University and a Fellow-in-Residence at the C.D. Howe Institute. Nic Rivers

  2. ZnO and MgZnO Nanocrystalline Flexible Films: Optical and Material Properties

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

    Huso, Jesse; Morrison, John L.; Che, Hui; Sundararajan, Jency P.; Yeh, Wei Jiang; McIlroy, David; Williams, Thomas J.; Bergman, Leah

    2011-01-01

    An emerging material for flexible UV applications isMgxZn1?xO which is capable of tunable bandgap and luminescence in the UV range of ~3.4?eV–7.4?eV depending on the compositionx. Studies on the optical and material characteristics of ZnO and Mg0.3Zn0.7O nanocrystalline flexible films are presented. The analysis indicates that the ZnO and Mg0.3Zn0.7O have bandgaps of 3.34?eV and 4.02?eV, respectively. The photoluminescence (PL) of the ZnO film was found to exhibit a structural defect-related emission at ~3.316?eV inherent to the nanocrystalline morphology. The PL of the Mg0.3Zn0.7O film exhibits two broad peaks at 3.38?eV and at 3.95?eV that are discussed in terms ofmore »the solubility limit of the ZnO-MgO alloy system. Additionally, external deformation of the film did not have a significant impact on its properties as indicated by the Raman LO-mode behavior, making these films attractive for UV flexible applications.« less

  3. Homoepitaxy of ZnO and MgZnO Films at 90 °C

    SciTech Connect (OSTI)

    Ehrentraut, Dirk; Goh, Gregory K.L.; Fujii, Katsushi; Ooi, Chin Chun; Quang, Le Hong; Fukuda, Tsuguo; Kano, Masataka; Zhang, Yuantao; Matsuoka, Takashi

    2014-06-01

    The aqueous synthesis of uniform single crystalline homoepitaxial zinc oxide, ZnO, and magnesium zinc oxide, Mg{sub x}Zn{sub 1?x}O, films under very low temperature conditions at T=90 °C and ambient pressure has been explored. A maximum Mg content of 1 mol% was recorded by energy dispersive spectroscopy. The growth on the polar (0 0 0 1) and (0 0 0 1¯) faces resulted in films that are strongly different in their structural and optical quality as evidenced by high-resolution X-ray diffraction, secondary electron microscopy, and photoluminescence. This is a result of the chemistry and temperature of the solution dictating the stability range of growth-governing metastable species. The use of trisodium citrate, Na{sub 3}C{sub 6}H{sub 5}O{sub 7}, yielded coalesced, mirror-like homoepitaxial films whereas adding magnesium nitrate hexahydrate, Mg(NO{sub 3}){sub 2}·6H{sub 2}O, favors the growth of films with pronounced faceting. - Graphical abstract: Homoepitaxial ZnO films grown from aqueous solution below boiling point of water on a ZnO substrate with off-orientation reveal parallel grooves that are characterized by (1 0 1{sup ¯} 1) facets. Adding trisodium citrate yields closed, single-crystalline ZnO films, which can further be functionalized. Alloying with MgO yields MgZnO films with low Mg content only. - Highlights: • A simple method to synthesize uniform single crystalline homoepitaxial ZnO and MgZnO films. • ZnO growth on (0 0 0 1) and (0 0 0 1{sup ¯}) face resulted in films that are strongly different in their structural and optical quality. • Single crystalline MgZnO film was fabricated under mild conditions (90 °C and ambient pressure). • Mg incorporation of nearly 1 mol% was obtained while maintaining single phase wurtzite structure.

  4. Semitransparent ultrathin CdTe solar cells Semitransparent ultrathin CdTe solar cells and durabilityand durability

    E-Print Network [OSTI]

    Rollins, Andrew M.

    Semitransparent ultrathin CdTe solar cells Semitransparent ultrathin CdTe solar cells lines · Thinfilm CIGS--not available in transparent form · Dye sensitized solar thin films· Dye.E. McCandless, W.A. Buchanan. "High throughput processing of CdTe/CdS solar cells with thin absorber

  5. CdTe/CdS solar cells on flexible substrates Xavier Mathew a,*, J. Pantoja Enriquez a

    E-Print Network [OSTI]

    Romeo, Alessandro

    CdTe/CdS solar cells on flexible substrates Xavier Mathew a,*, J. Pantoja Enriquez a , Alessandro of CdTe/CdS solar cells on flexible substrates is reviewed in this article. Photovoltaic structures. The specific power of the solar cells is an important factor in space applications and hence development

  6. Chemical spots and their dynamical evolution on HgMn stars

    E-Print Network [OSTI]

    Korhonen, Heidi; Briquet, Maryline; Gonzalez, Federico; Savanov, Igor

    2010-01-01

    Our recent studies of late B-type stars with HgMn peculiarity revealed for the first time the presence of fast dynamical evolution of chemical spots on their surfaces. These observations suggest a hitherto unknown physical process operating in the stars with radiative outer envelopes. Furthermore, we have also discovered existence of magnetic fields on these stars that have up to now been thought to be non-magnetic. Here we will discuss the dynamical spot evolution on HD 11753 and our new results on magnetic fields on AR Aur.

  7. Quantum Anomalous Hall Effect in Hg_1-yMn_yTe Quantum Wells

    SciTech Connect (OSTI)

    Liu, Chao-Xing; /Tsinghua U., Beijing /Stanford U., Phys. Dept.; Qi, Xiao-Liang; /Stanford U., Phys. Dept.; Dai, Xi; Fang, Zhong; /Beijing, Inst. Phys.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-03-19

    The quantum Hall effect is usually observed when the two-dimensional electron gas is subjected to an external magnetic field, so that their quantum states form Landau levels. In this work we predict that a new phenomenon, the quantum anomalous Hall effect, can be realized in Hg{sub 1-y}Mn{sub y}Te quantum wells, without the external magnetic field and the associated Landau levels. This effect arises purely from the spin polarization of the Mn atoms, and the quantized Hall conductance is predicted for a range of quantum well thickness and the concentration of the Mn atoms. This effect enables dissipationless charge current in spintronics devices.

  8. Quantum Hall effect in HgTe quantum wells at nitrogen temperatures

    SciTech Connect (OSTI)

    Kozlov, D. A. Kvon, Z. D.; Mikhailov, N. N.; Dvoretskii, S. A.; Weishäupl, S.; Krupko, Y.; Portal, J.-C.

    2014-09-29

    We report on the observation of quantized Hall plateaus in a system of two-dimensional Dirac fermions, implemented in a 6.6?nm HgTe quantum well at magnetic fields up to 34?T at nitrogen temperatures. The activation energies determined from the temperature dependence of the longitudinal resistivity are found to be almost equal for the filling factors ? of 1 and 2. This indicates that the large values of the g-factor (about 30–40) remain unchanged at very strong magnetic fields.

  9. Analysis of chemically deposited CdSe and CdS thin films

    E-Print Network [OSTI]

    Osuji, R U

    2002-01-01

    We have successfully deposited quality polycrystalline thin films of CdSe and CdS on Corning 7059 glass slides by the electroless chemical bath technique at room temperature (~27 $^\\circ$C). X-ray analysis confirmed the successful deposition of CdSe and CdS thin films. Our grown CdSe film thickness ranged from 0.10 $\\mu$m. to 0.80 $\\pm$ 0.01 $\\mu$m and the CdS film thickness ranged from 0.10 $\\mu$m to 1.00 $\\pm$ 0.01 $\\mu$m. The scanning electron micrograph of the films reveals uniform film surface. The energy gaps, $E_g$ determined for our CdSe and CdS films have average values of 1.70 $\\pm$ 0.04 eV and 2.15 $\\pm$ 0.04 eV respectively. The films have high absorbance in the 0.35 $\\mu$m - 0.85 $\\mu$m range. These qualities make them suitable for use in thin film solar cell technology.

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

    SciTech Connect (OSTI)

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

    2012-12-19

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

  11. One-volt p-InP/n-CdSe regenerative photoelectrochemical cell

    SciTech Connect (OSTI)

    Ang, P.G.P.; Sammells, A.F.

    1983-08-01

    Features and performance of a two-photoelectrode regenerative photoelectrochemical (PEC) cell that yielded a combined photovoltage of more than one volt are reported. The photoanode was n-CdSe, the photocathode was p-InP, and the electrolyte was aqueous sulfide/polysulfide. Details of the fabrication process are provided, including formation of an ohmic contact by sputter deposited gold and then electroplating the photocathode with Zn, followed by a final sputtered gold layer. Tests under 100 mW/sq cm illumination of the unoptimized regenerative cell produced an open circuit voltage of 1.15 V, a short circuit current of 24 mA/sq cm, a fill factor of 0.40, and an overall efficiency of 5.5 percent.

  12. Fluorescence modulation in single CdSe quantum dots by moderate applied electric fields

    SciTech Connect (OSTI)

    LeBlanc, Sharonda J. [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); McClanahan, Mason R.; Moyer, Tully; Moyer, Patrick J. [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); Jones, Marcus [Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States)

    2014-01-21

    Single molecule time-resolved fluorescence spectroscopy of CdSe/ZnS core-shell quantum dots (QDs) under the influence of moderate applied electric fields reveals distributed emission from states which are neither fully on nor off and pronounced changes in the excited state decay. The data suggest that a 54?kV/cm applied electric field causes small perturbations to the QD surface charge distribution, effectively increasing the surface trapping probability and resulting in the appearance of gray states. We present simultaneous blinking and fluorescence decay results for two sets of QDs, with and without an applied electric field. Further kinetic modeling analysis suggests that a single trapped charged cannot be responsible for a blinking off event.

  13. Development and characterization of PCDTBT:CdSe QDs hybrid solar cell

    SciTech Connect (OSTI)

    Dixit, Shiv Kumar Bhatnagar, Chhavi Kumari, Anita Madhwal, Devinder Bhatnagar, P. K. Mathur, P. C.

    2014-10-15

    Solar cell consisting of low band gap polymer poly[N-900-hepta-decanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10, 30-benzothiadiazole)] (PCDTBT) as donor and cadmium selenide/zinc sulphide (CdSe/ZnS) core shell quantum dots (QDs) as an acceptor has been developed. The absorption measurements show that the absorption coefficient increases in bulk heterojunction (BHJ) structure covering broad absorption spectrum (200nm–700nm). Also, the photoluminescence (PL) of the PCDTBT:QDs film is found to decrease by an order of magnitude showing a significant transfer of electrons to the QDs. With this approach and under broadband white light with an irradiance of 8.19 mW/cm{sup 2}, we have been able to achieve a power conversion efficiency (PCE) of 3.1 % with fill factor 0.42 for our typical solar cell.

  14. Report on International Collaboration Involving the FE Heater and HG-A Tests at Mont Terri

    SciTech Connect (OSTI)

    Houseworth, Jim; Rutqvist, Jonny; Asahina, Daisuke; Chen, Fei; Vilarrasa, Victor; Liu, Hui-Hai; Birkholzer, Jens

    2013-11-06

    Nuclear waste programs outside of the US have focused on different host rock types for geological disposal of high-level radioactive waste. Several countries, including France, Switzerland, Belgium, and Japan are exploring the possibility of waste disposal in shale and other clay-rich rock that fall within the general classification of argillaceous rock. This rock type is also of interest for the US program because the US has extensive sedimentary basins containing large deposits of argillaceous rock. LBNL, as part of the DOE-NE Used Fuel Disposition Campaign, is collaborating on some of the underground research laboratory (URL) activities at the Mont Terri URL near Saint-Ursanne, Switzerland. The Mont Terri project, which began in 1995, has developed a URL at a depth of about 300 m in a stiff clay formation called the Opalinus Clay. Our current collaboration efforts include two test modeling activities for the FE heater test and the HG-A leak-off test. This report documents results concerning our current modeling of these field tests. The overall objectives of these activities include an improved understanding of and advanced relevant modeling capabilities for EDZ evolution in clay repositories and the associated coupled processes, and to develop a technical basis for the maximum allowable temperature for a clay repository. The R&D activities documented in this report are part of the work package of natural system evaluation and tool development that directly supports the following Used Fuel Disposition Campaign (UFDC) objectives: ? Develop a fundamental understanding of disposal-system performance in a range of environments for potential wastes that could arise from future nuclear-fuel-cycle alternatives through theory, simulation, testing, and experimentation. ? Develop a computational modeling capability for the performance of storage and disposal options for a range of fuel-cycle alternatives, evolving from generic models to more robust models of performance assessment. For the purpose of validating modeling capabilities for thermal-hydro-mechanical (THM) processes, we developed a suite of simulation models for the planned full-scale FE Experiment to be conducted in the Mont Terri URL, including a full three-dimensional model that will be used for direct comparison to experimental data once available. We performed for the first time a THM analysis involving the Barcelona Basic Model (BBM) in a full three-dimensional field setting for modeling the geomechanical behavior of the buffer material and its interaction with the argillaceous host rock. We have simulated a well defined benchmark that will be used for codeto- code verification against modeling results from other international modeling teams. The analysis highlights the complex coupled geomechanical behavior in the buffer and its interaction with the surrounding rock and the importance of a well characterized buffer material in terms of THM properties. A new geomechanical fracture-damage model, TOUGH-RBSN, was applied to investigate damage behavior in the ongoing HG-A test at Mont Terri URL. Two model modifications have been implemented so that the Rigid-Body-Spring-Network (RBSN) model can be used for analysis of fracturing around the HG-A microtunnel. These modifications are (1) a methodology to compute fracture generation under compressive stress conditions and (2) a method to represent anisotropic elastic and strength properties. The method for computing fracture generation under compressive load produces results that roughly follow trends expected for homogeneous and layered systems. Anisotropic properties for the bulk rock were represented in the RBSN model using layered heterogeneity and gave bulk material responses in line with expectations. These model improvements were implemented for an initial model of fracture damage at the HG-A test. While the HG-A test model results show some similarities with the test observations, differences between the model results and observations remain.

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

    SciTech Connect (OSTI)

    Jacquat, Olivier; Voegelin, Andreas; Villard, Andre; Marcus, Matthew A.; Kretzschmar, Ruben

    2007-10-15

    Recent studies demonstrated that Zn-phyllosilicate- and Zn-layered double hydroxide-type (Zn-LDH) precipitates may form in contaminated soils. However, the influence of soil properties and Zn content on the quantity and type of precipitate forming has not been studied in detail so far. In this work, we determined the speciation of Zn in six carbonate-rich surface soils (pH 6.2 to 7.5) contaminated by aqueous Zn in the runoff from galvanized power line towers (1322 to 30090 mg/kg Zn). Based on 12 bulk and 23 microfocused extended X-ray absorption fine structure (EXAFS) spectra, the number, type and proportion of Zn species were derived using principal component analysis, target testing, and linear combination fitting. Nearly pure Zn-rich phyllosilicate and Zn-LDH were identified at different locations within a single soil horizon, suggesting that the local availabilities of Al and Si controlled the type of precipitate forming. Hydrozincite was identified on the surfaces of limestone particles that were not in direct contact with the soil clay matrix. With increasing Zn loading of the soils, the percentage of precipitated Zn increased from {approx}20% to {approx}80%, while the precipitate type shifted from Zn-phyllosilicate and/or Zn-LDH at the lowest studied soil Zn contents over predominantly Zn-LDH at intermediate loadings to hydrozincite in extremely contaminated soils. These trends were in agreement with the solubility of Zn in equilibrium with these phases. Sequential extractions showed that large fractions of soil Zn ({approx}30% to {approx}80%) as well as of synthetic Zn-kerolite, Zn-LDH, and hydrozincite spiked into uncontaminated soil were readily extracted by 1 M NH{sub 4}NO{sub 3} followed by 1 M NH{sub 4}-acetate at pH 6.0. Even though the formation of Zn precipitates allows for the retention of Zn in excess to the adsorption capacity of calcareous soils, the long-term immobilization potential of these precipitates is limited.

  16. 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 substitution of Cd CuCd 0=À #12; #12; play critical roles in p-doping of CdTe in CdS/CdTe thin film solar cells in Fig. 1. As for the CdTe polycrystalline thin film in a CdS/CdTe solar cell, it is still being debated

  17. IDS120h GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING (P11/P12 'POINTS') (CONT.)

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120h GEOMETRY WITH MODIFIED Hg POOL VESSEL SIMULATIONS FOR 60% W + 40% He SHIELDING (P11/P12hm: (m IS FOR) modified Hg pool vessel IN IDS120h. # 1E5 AND 5E5 SIMULATIONS COMPARISON = y = 0.12 cm. 2 #12;3 IDS120hm GEOMETRY = IDS120h WITH MODIFIED Hg POOL VESSEL AND SHIFTED Be WIDOW

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

    E-Print Network [OSTI]

    Lee, Kwang Jik

    2006-10-30

    After hydrolyzing zinc acetate in methanol solution, spherical ZnO nanoparticles in the size range from about 2.5 to 5 nm were synthesized by maintaining a ZnO concentration of 0.02M. Compared to ZnO nanoparticles prepared via other methods...

  19. Optical emission spectroscopy of metal-halide lamps: Radially resolved atomic state distribution functions of Dy and Hg

    SciTech Connect (OSTI)

    Nimalasuriya, T.; Flikweert, A.J.; Stoffels, W.W.; Haverlag, M.; Mullen, J.J.A.M. van der; Pupat, N.B.M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Ecole Nationale Superieure de Chimie de Paris, 11 Rue Pierre et Marie Curie, 75005 Paris (France)

    2006-03-01

    Absolute line intensity measurements are performed on a metal-halide lamp. Several transitions of atomic and ionic Dy and atomic Hg are measured at different radial positions from which we obtain absolute atomic and ionic Dy intensity profiles. From these profiles we construct the radially resolved atomic state distribution function (ASDF) of the atomic and ionic Dy and the atomic Hg. From these ASDFs several quantities are determined as functions of radial position, such as the (excitation) temperature, the ion ratio Hg{sup +}/Dy{sup +}, the electron density, the ground state, and the total density of Dy atoms and ions. Moreover, these ASDFs give us insight about the departure from equilibrium. The measurements show a hollow density profile for the atoms and the ionization of atoms in the center. In the outer parts of the lamp molecules dominate.

  20. H.G. Okuno and M. Ali (Eds.): IEA/AIE 2007, LNAI 4570, pp. 444453, 2007. Springer-Verlag Berlin Heidelberg 2007

    E-Print Network [OSTI]

    Cho, Sung-Bae

    H.G. Okuno and M. Ali (Eds.): IEA/AIE 2007, LNAI 4570, pp. 444­453, 2007. © Springer-Verlag Berlin

  1. H.G. Okuno and M. Ali (Eds.): IEA/AIE 2007, LNAI 4570, pp. 621632, 2007. Springer-Verlag Berlin Heidelberg 2007

    E-Print Network [OSTI]

    Bosse, Tibor

    H.G. Okuno and M. Ali (Eds.): IEA/AIE 2007, LNAI 4570, pp. 621­632, 2007. © Springer-Verlag Berlin

  2. H.G. Okuno and M. Ali (Eds.): IEA/AIE 2007, LNAI 4570, pp. 796805, 2007. Springer-Verlag Berlin Heidelberg 2007

    E-Print Network [OSTI]

    Cho, Sung-Bae

    H.G. Okuno and M. Ali (Eds.): IEA/AIE 2007, LNAI 4570, pp. 796­805, 2007. © Springer-Verlag Berlin

  3. Preparation, structural and optical characterization of ZnO, ZnO: Al nanopowder

    SciTech Connect (OSTI)

    Mohan, R. Raj [Department of ECE, Gojan School of Business and Technology, Chennai (India); Rajendran, K. [Department of Electronics, Government Arts College for Women, Ramanathapuram, TN (India); Sambath, K. [Department of ECS, Sri Krishna Arts and Science College, Coimbatore, TN (India)

    2014-01-28

    In this paper, ZnO and ZnO:Al nanopowders have been synthesized by low cost hydrothermal method. Zinc nitrate, hexamethylenetetramine (HMT) and aluminium nitrate are used as precursors for ZnO and AZO with different molar ratios. The structural and optical characterization of doped and un-doped ZnO powders have been investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDAX), photoluminescence (PL) and ultra violet visible (UV-Vis) absorption studies. The SEM results show that the hydrothermal synthesis can be used to obtain nanoparticles with different morphology. It is observed that the grain size of the AZO nanoparticles increased with increasing of Al concentration. The PL measurement of AZO shows that broad range of green emission around 550nm with high intensity. The green emission resulted mainly because of intrinsic defects.

  4. Emission and Excitation Spectra of ZnO:Ga and ZnO:Ga,N Ceramics

    E-Print Network [OSTI]

    P. A. Rodnyi; I. V. Khodyuk; E. I. Gorokhova; S. B. Mikhrin; P. Dorenbos

    2010-09-07

    The spectral characteristics of ZnO:Ga and ZnO:Ga,N ceramics prepared by uniaxial hot pressing have been investigated. At room temperature, the edge (exciton) band at 3.12 eV dominates in the luminescence spectra of ZnO:Ga, while a wide luminescence band at 2.37 eV, which is likely to be due to zinc vacancies, is observed in the spectra of ZnO:Ga,N. Upon heating, the edge band maximum shifts to lower energies and the bandwidth increases. The extrapolated position of the edge-band maximum at zero temperature, Em(0) = 3.367 +/- 0.005 eV, is in agreement with the data for thin zinc oxide films. The luminescence excitation spectra in the range from 3 to 6.5 eV are reported and the mechanism of energy transfer to excitons and luminescence centers is considered.

  5. Twinning effect on photoluminescence spectra of ZnSe nanowires

    SciTech Connect (OSTI)

    Xu, Jing; Wang, Chunrui Wu, Binhe; Xu, Xiaofeng; Chen, Xiaoshuang; Oh, Hongseok; Baek, Hyeonjun; Yi, Gyu-Chul

    2014-11-07

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

  6. Optical Properties of ZnO-Alloyed Nanocrystalline Films

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

    Che, Hui; Huso, Jesse; Morrison, John L.; Thapa, Dinesh; Huso, Michelle; Yeh, Wei Jiang; Tarun, M. C.; McCluskey, M. D.; Bergman, Leah

    2012-01-01

    ZnO is emerging as one of the materials of choice for UV applications. It has a deep excitonic energy level and a direct bandgap of ~3.4?eV. Alloying ZnO with certain atomic constituents adds new optical and electronic functionalities to ZnO. This paper presents research onMgxZn1?xOandZnS1?xOxnanocrystalline flexible films, which enable tunable optical properties in the deep-UV and in the visible range. The ZnO andMg0.3Zn0.7Ofilms were found to have bandgaps at 3.35 and 4.02?eV, respectively. The photoluminescence of theMg0.3Zn0.7Oexhibited a bandedge emission at 3.95?eV, and at lower energy 3.38?eV due to the limited solubility inherent to these alloys.ZnS0.76O0.24andZnS0.16O0.84were found tomore »have bandgaps at 3.21 and 2.65?eV, respectively. The effect of nitrogen doping onZnS0.16O0.84is discussed in terms of the highly lattice mismatched nature of these alloys and the resulting valence-band modification.« less

  7. Novel Scintillation Material - ZnO Transparent Ceramics

    E-Print Network [OSTI]

    Rodnyi, P A; Gorokhova, E I; Kozlovskii, S S; Khanin, V M; Khodyuk, I V

    2011-01-01

    ZnO-based scintillation ceramics for application in HENPA LENPA analyzers have been investigated. The following ceramic samples have been prepared: undoped ones (ZnO), an excess of zinc in stoichiometry (ZnO:Zn), doped with gallium (ZnO:Ga) and lithium (ZnO:Li). Optical transmission, x-ray excited emission, scintillation decay and pulse height spectra were measured and analyzed. Ceramics have reasonable transparency in visible range (up to 60% for 0.4 mm thickness) and energy resolution (14.9% at 662 keV Cs137 gamma excitation). Undoped ZnO shows slow (1.6 {\\mu}s) luminescence with maximum at 2.37 eV and light yield about 57% of CsI:Tl. ZnO:Ga ceramics show relatively low light yield with ultra fast decay time (1 ns). Lithium doped ceramics ZnO:Li have better decay time than undoped ZnO with fair light yield. ZnO:Li ceramics show good characteristics under alpha-particle excitation and can be applied for the neutral particle analyzers.

  8. Novel Scintillation Material - ZnO Transparent Ceramics

    E-Print Network [OSTI]

    P. A. Rodnyi; K. A. Chernenko; E. I. Gorokhova; S. S. Kozlovskii; V. M. Khanin; I. V. Khodyuk

    2011-11-09

    ZnO-based scintillation ceramics for application in HENPA LENPA analyzers have been investigated. The following ceramic samples have been prepared: undoped ones (ZnO), an excess of zinc in stoichiometry (ZnO:Zn), doped with gallium (ZnO:Ga) and lithium (ZnO:Li). Optical transmission, x-ray excited emission, scintillation decay and pulse height spectra were measured and analyzed. Ceramics have reasonable transparency in visible range (up to 60% for 0.4 mm thickness) and energy resolution (14.9% at 662 keV Cs137 gamma excitation). Undoped ZnO shows slow (1.6 {\\mu}s) luminescence with maximum at 2.37 eV and light yield about 57% of CsI:Tl. ZnO:Ga ceramics show relatively low light yield with ultra fast decay time (1 ns). Lithium doped ceramics ZnO:Li have better decay time than undoped ZnO with fair light yield. ZnO:Li ceramics show good characteristics under alpha-particle excitation and can be applied for the neutral particle analyzers.

  9. Abundance analysis of SB2 binary stars with HgMn primaries

    E-Print Network [OSTI]

    T. Ryabchikova

    1998-05-06

    We present a short review of the abundances in the atmospheres of SB2 systems with Mercury-Manganese (HgMn) primaries. Up to now a careful study has been made for both components of 8 out of 17 known SB2 binaries with orbital periods shorter than 100 days and mass ratio ranging from 1.08 to 2.2. For all eight systems we observe a lower Mn abundance in the secondary's atmospheres than in the primary's. Significant difference in the abundances is also found for some peculiar elements such as Ga, Xe, Pt. All secondary stars with effective temperatures less than 10000 K show abundance characteristics typical of the metallic-line stars.

  10. Advanced Combustion Modeling with STAR-CD using Transient Flemelet...

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

    Modeling with STAR-CD using Transient Flemelet Models: TIF and TPV Advanced Combustion Modeling with STAR-CD using Transient Flemelet Models: TIF and TPV Presentation given at the...

  11. Metal-Semiconductor Zn-ZnO Core-Shell Nanobelts and Nanotubes Xiang Yang Kong,, Yong Ding, and Zhong Lin Wang*,

    E-Print Network [OSTI]

    Wang, Zhong L.

    with silica,10 tape structured nanobelts of SnO2 and TiO2,11 core-shell structured Si-Ge nanowires,12 and ZnMetal-Semiconductor Zn-ZnO Core-Shell Nanobelts and Nanotubes Xiang Yang Kong,, Yong Ding-semiconductor Zn-ZnO core-shell nanobelts and nanotubes have been synthesized. The core is a belt-shaped Zn single

  12. High Efficiency CdTe/CdS Thin Film Solar Cells Prepared by Treating CdTe Films with a Freon Gas in Substitution of CdCl2

    E-Print Network [OSTI]

    Romeo, Alessandro

    High Efficiency CdTe/CdS Thin Film Solar Cells Prepared by Treating CdTe Films with a Freon Gas a sufficient conversion efficiency to be considered for an industrial application. The fabrication process observed. Solar cell efficiency obtained with this treatment, close to 16%, is comparable if not larger

  13. Impact of air-exposure on the chemical and electronic structure ofZnO:Zn3N2 thin films

    SciTech Connect (OSTI)

    Bar, M.; Ahn, K.-S.; Shet, S.; Yan, Y.; Weinhardt, L.; Fuchs, O.; Blum, M.; Pookpanratana, S.; George, K.; Yang, W.; Denlinger, J.D.; Al-Jassim, M.; Heske, C.

    2008-09-08

    The chemical and electronic surface structure of ZnO:Zn3N2 ("ZnO:N") thin films with different N contents was investigated by soft x-ray emission spectroscopy. Upon exposure to ambient air (in contrast to storage in vacuum), the chemical and electronic surface structure of the ZnO:N films changes substantially. In particular, we find that the Zn3N2/(Zn3N2+ZnO) ratio decreases with exposure time and that this change depends on the initial N content. We suggest a degradation mechanism based on the reaction of the Zn3N2 content with atmospheric humidity.

  14. Irradiation damage studies of high power accelerator materials N. Simos a,1,*, H.G. Kirk a

    E-Print Network [OSTI]

    McDonald, Kirk

    and composites. These new high-perfor- mance materials, which appear to possess the right combination to proton beams to assess the survivability potential of these new alloys and composite materials. WhileIrradiation damage studies of high power accelerator materials N. Simos a,1,*, H.G. Kirk a , P

  15. Pinning lattice: Effect of rhenium doping on the microstructural evolution from Tl-2212 to Hg-1212 films during cation exchange

    E-Print Network [OSTI]

    Wu, Judy; Zhao, H.

    2004-08-15

    them. HgBa2CaCu2O6 films obtained from these Re-doped Tl-2212 precursor films have much improved microstructures with the pore dimension reduced by an order of magnitude. (C) 2004 American Institute of Physics....

  16. Double-Sided CdS and CdSe Quantum Dot Co-Sensitized ZnO Nanowire Arrays for

    E-Print Network [OSTI]

    Li, Yat

    for photoelectrochemical (PEC) hydrogen generation. The double-sided design represents a simple analogue of tandem cell generation and can be possibly applied to other applications such as nanostructured tandem photovoltaic cells the absorption of solar light.15,16 However, rational synthesis of the multijunction nanostructures

  17. I-III-VI.sub.2 based solar cell utilizing the structure CuInGaSe.sub.2 CdZnS/ZnO

    DOE Patents [OSTI]

    Chen, Wen S. (Seattle, WA); Stewart, John M. (Seattle, WA)

    1992-01-07

    A thin film I-III-VI.sub.2 based solar cell having a first layer of copper indium gallium selenide, a second layer of cadmium zinc sulfide, a double layer of zinc oxide, and a metallization structure comprised of a layer of nickel covered by a layer of aluminum. An optional antireflective coating may be placed on said metallization structure. The cadmium zinc sulfide layer is deposited by means of an aqueous solution growth deposition process and may actually consist of two layers: a low zinc content layer and a high zinc content layer. Photovoltaic efficiencies of 12.5% at Air Mass 1.5 illumination conditions and 10.4% under AMO illumination can be achieved.

  18. Spin noise spectroscopy of ZnO

    SciTech Connect (OSTI)

    Horn, H.; Berski, F.; Hübner, J.; Oestreich, M.; Balocchi, A.; Marie, X.; Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A.

    2013-12-04

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

  19. Double beta decays of {sup 106}Cd

    SciTech Connect (OSTI)

    Suhonen, Jouni [Department of Physics, P.O. Box 35 (YFL), FI-40014 University of Jyvaeskylae (Finland)

    2011-12-16

    The two-neutrino (2{nu}2{beta}) and neutrinoless (0{nu}2{beta}) double beta decays of {sup 106}Cd are studied for the transitions to the ground state 0{sub gs}{sup +} and 0{sup +} and 2{sup +} excited states in {sup 106}Pd by using realistic many-body wave functions calculated in the framework of the quasiparticle random-phase approximation. Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. All the possible channels, {beta}{sup +}{beta}{sup +}, {beta}{sup +}EC, and ECEC, are discussed for both the 2{nu}2{beta} and 0{nu}2{beta} decays. The associated half-lives are computed and particular attention is devoted to the study of the detectability of the resonant neutrinoless double electron capture (R0{nu}ECEC) process in {sup 106}Cd. The calculations of the present article constitute the thus far most complete and up-to-date investigation of the double-beta-decay properties of {sup 106}Cd.

  20. Empirical correlations between the arrhenius' parameters of impurities' diffusion coefficients in CdTe crystals

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

    Shcherbak, L.; Kopach, O.; Fochuk, P.; James, R. B.; Bolotnikov, A. E.

    2015-01-21

    Understanding of self- and dopant-diffusion in semiconductor devices is essential to our being able to assure the formation of well-defined doped regions. In this paper, we compare obtained in the literature up to date the Arrhenius’ parameters (D=D0exp(–?Ea/kT)) of point-defect diffusion coefficients and the I-VII groups impurities in CdTe crystals and films. We found that in the diffusion process there was a linear dependence between the pre-exponential factor, D0, and the activation energy, ?Ea, of different species: This was evident in the self-diffusivity and isovalent impurity Hg diffusivity as well as for the dominant IIIA and IVA groups impurities andmore »Chlorine, except for the fast diffusing elements (e.g., Cu and Ag), chalcogens O, S, and Se, halogens I and Br as well as the transit impurities Mn, Co, Fe. As a result, reasons of the lack of correspondence of the data to compensative dependence are discussed.« less

  1. Copper migration in CdTe heterojunction solar cells

    SciTech Connect (OSTI)

    Chou, H.C.; Rohatgi, A.; Jokerst, N.M.; Thomas, E.W.; Kamra, S.

    1996-07-01

    CdTe solar cells were fabricated by depositing a Au/Cu contact with Cu thickness in the range of 50 to 150A on polycrystalline CdTe/CdS/SnO{sub 2} glass structures. The increase in Cu thickness improves ohmic contact and reduces series resistance (R{sub s}), but the excess Cu tends to diffuse into CdTe and lower shunt resistance (R{sub sh}) and cell performance. Light I-V and secondary ion mass spectroscopy (SIMS) measurements were performed to understand the correlations between the Cu contact thickness, the extent of Cu incorporation in the CdTe cells, and its impact on the cell performance. The CdTe/CdS/SnO{sub 2} glass, CdTe/CdS/GaAs, and CdTe/GaAs structures were prepared in an attempt to achieve CdTe films with different degrees of crystallinity and grain size. A large grain polycrystalline CdTe thin film solar cell was obtained for the first time by selective etching the GaAs substrate coupled with the film transfer onto a glass substrate. SIMS measurement showed that poor crystallinity and smaller grain size of the CdTe film promotes Cu diffusion and decreases the cell performance. Therefore, grain boundaries are the main conduits for Cu migration and larger CdTe grain size or alternate method of contact formation can mitigate the adverse effect of Cu and improve the cell performance. 15 refs., 1 fig.,6 tabs.

  2. Optical, luminescence, and scintillation properties of ZnO and ZnO:Ga ceramics

    E-Print Network [OSTI]

    E. I. Gorokhova; G. V. Anan'eva; V. A. Demidenko; P. A. Rodny; I. V. Khodyuk; E. D. Bourret-Courchesne

    2010-09-07

    Uniaxial hot pressing has been used to obtain ceramics based on zinc oxide, and their optical, x-ray-structure, luminescence, and scintillation characteristics have been studied. It is shown that, by changing the concentration of the dopant (Ga) and the codopant (N), it is possible to change the intensities of the edge band (397.5 nm) and the intraband luminescence (510 nm) of the ZnO luminescence, as well as their ratio. Undoped ZnO ceramic has good transparency in the visible region and fairly high luminous yield: 9050 photons per MeV. Ceramic ZnO:Ga possesses intense edge luminescence with a falloff time of about 1 ns.

  3. Evolution of quasiparticle states with and without a Zn impurity...

    Office of Scientific and Technical Information (OSTI)

    Evolution of quasiparticle states with and without a Zn impurity in doped 122 iron pnictides Citation Details In-Document Search Title: Evolution of quasiparticle states with and...

  4. Controllable Template Synthesis of Superconducting Zn Nanowires with

    E-Print Network [OSTI]

    June 9, 2005 ABSTRACT A systematic study was conducted on the fabrication, structural characterization by electrodepositing Zn into commercially available polycarbonate (PC) or anodic aluminum oxide (AAO) membranes

  5. Characterization of cancer stem cell properties of CD24 and CD26-positive human malignant mesothelioma cells

    SciTech Connect (OSTI)

    Yamazaki, Hiroto; Naito, Motohiko; Ghani, Farhana Ishrat [Division of Clinical Immunology, Institute of Medical Science, University of Tokyo, Tokyo (Japan)] [Division of Clinical Immunology, Institute of Medical Science, University of Tokyo, Tokyo (Japan); Dang, Nam H. [Division of Hematology/Oncology, University of Florida Shands Cancer Center, Gainesville, FL 32610 (United States)] [Division of Hematology/Oncology, University of Florida Shands Cancer Center, Gainesville, FL 32610 (United States); Iwata, Satoshi [Division of Clinical Immunology, Institute of Medical Science, University of Tokyo, Tokyo (Japan)] [Division of Clinical Immunology, Institute of Medical Science, University of Tokyo, Tokyo (Japan); Morimoto, Chikao, E-mail: morimoto@ims.u-tokyo.ac.jp [Division of Clinical Immunology, Institute of Medical Science, University of Tokyo, Tokyo (Japan)] [Division of Clinical Immunology, Institute of Medical Science, University of Tokyo, Tokyo (Japan)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer We focused on CD24 and CD26 for further analysis of CSC properties in MM. Black-Right-Pointing-Pointer Their expressions were correlated with chemoresistance, cell growth, and invasion. Black-Right-Pointing-Pointer Their expressions were also correlated with several cancer related genes. Black-Right-Pointing-Pointer The expression of each marker was correlated with different CSC property in Meso1. Black-Right-Pointing-Pointer Phosphorylation of ERK by EGF was regulated by expression of CD26, but not CD24. -- Abstract: Malignant mesothelioma (MM) is an asbestos-related malignancy characterized by rapid growth and poor prognosis. In our previous study, we have demonstrated that several cancer stem cell (CSC) markers correlated with CSC properties in MM cells. Among these markers, we focused on two: CD24, the common CSC marker, and CD26, the additional CSC marker. We further analyzed the CSC properties of CD24 and CD26-positve MM cells. We established RNAi-knockdown cells and found that these markers were significantly correlated with chemoresistance, proliferation, and invasion potentials in vitro. Interestingly, while Meso-1 cells expressed both CD24 and CD26, the presence of each of these two markers was correlated with different CSC property. In addition, downstream signaling of these markers was explored by microarray analysis, which revealed that their expressions were correlated with several cancer-related genes. Furthermore, phosphorylation of ERK by EGF stimulation was significantly affected by the expression of CD26, but not CD24. These results suggest that CD24 and CD26 differentially regulate the CSC potentials of MM and could be promising targets for CSC-oriented therapy.

  6. Evidence of significant down-conversion in a Si-based solar cell using CuInS{sub 2}/ZnS core shell quantum dots

    SciTech Connect (OSTI)

    Gardelis, Spiros Nassiopoulou, Androula G.

    2014-05-05

    We report on the increase of up to 37.5% in conversion efficiency of a Si-based solar cell after deposition of light-emitting Cd-free, CuInS{sub 2}/ZnS core shell quantum dots on the active area of the cell due to the combined effect of down-conversion and the anti- reflecting property of the dots. We clearly distinguished the effect of down-conversion from anti-reflection and estimated an enhancement of up to 10.5% in the conversion efficiency due to down-conversion.

  7. Microstructural evolutions in converting epitaxial Tl2Ba2CaCu2Ox thin films to epitaxial HgBa2CaCu2O6+delta thin films

    E-Print Network [OSTI]

    Wu, Judy; Siegal, M. P.; Xie, Y. Y.; Aytug, T.; Fang, L.

    2003-02-01

    Superconducting HgBa2CaCu2O6+delta (Hg-1212) thin films were obtained from Tl2Ba2CaCu2Ox (Tl-2212) precursor films using a cation-exchange process. In this process, Tl cations on the precursor lattice were thermally excited and then replaced with Hg...

  8. Trap Activation Energy and Transport Parameters of HgI$_2$ Crystals for Bubble-Plasma Diagnostics

    E-Print Network [OSTI]

    M. B. Miller; V. F. Kushniruk; A. V. Sermyagin

    2003-01-13

    In recent data on neutron induced acoustic cavitation in deuterium--containing liquids obtained by neutron measurements it was shown that very high temperatures could arise in some special cases. To study temperature of so--called bubble plasma it is desirable to have micro--detectors of X-rays, which can be prepared on the basis of room--temperature semiconductor detectors, in particular on mercuric iodide ($\\alpha$--HgI$_2$) crystals. Having in view this aim, the properties of gel--grown ($\\alpha$--HgI$_2$) crystals was studied by means of isothermal currents, and trap parameters was estimated. Results are promising for special aim of preparing X-ray detectors with moderate energy resolution needed in bubble--plasma diagnostic, though improving of crystal growing technology is necessary. {\\it PACS:} 29.40.Wk; 52.70.La {\\it Keywords:} X-ray and gamma--ray measurements; semiconductor detectors; mercuric iodide; plasma diagnostics; cavitation

  9. CD-2: Orogenic Belt | Open Energy Information

    Open Energy Info (EERE)

    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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank, Maine:Kansas: Energy Resources Jump to:Energy Inc -6CCC Federal2CD-2:

  10. cd ordering | netl.doe.gov

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLos AlamosSimulation Initiative ccsi.jpg The Carbon CaptureCD-DVD

  11. Cs6Ge8Zn: A Zintl Phase with Isolated Heteroatomic Clusters of Ge8Zn

    E-Print Network [OSTI]

    a single phase of Cs6Ge8Zn.8 The plate-like crystals of the compound are brittle, black, and with coal-like luster. Single-crystal studies unveiled a new type of cluster formation, a dimer of corner different types. The clusters of type A have only a horizontal mirror plane (Cm) while the clusters of type

  12. Dynamical evolution of titanium, strontium, and yttrium spots on the surface of the HgMn star HD 11753

    E-Print Network [OSTI]

    Briquet, M; Gonzalez, J F; Hubrig, S; Hackman, T

    2010-01-01

    Aims. We gathered about 100 high-resolution spectra of three typical HgMn (mercury-manganese) stars, HD 11753, HD 53244, and HD 221507, to search for slowly pulsating B-like pulsations and surface inhomogeneous distribution of various chemical elements. Methods. Classical frequency analysis methods were used to detect line profile variability and to determine the variation period. Doppler imaging reconstruction was performed to obtain abundance maps of chemical elements on the stellar surface. Results. For HD 11753, which is the star with the most pronounced variability, distinct spectral line profile changes were detected for Ti, Sr, Y, Zr, and Hg, whereas for HD 53244 and HD 221507 the most variable line profiles belong to the elements Hg and Y, respectively. We derived rotation periods for all three stars from the variations of radial velocities and equivalent widths of spectral lines belonging to inhomogeneously distributed elements: P_rot (HD 11753)=9.54 d, P_rot (HD 53244)=6.16 d, and P_rot (HD 221507)=...

  13. Results of Hg speciation testing on tanks 30, 32, and 37 depth samples

    SciTech Connect (OSTI)

    Bannochie, C. J.

    2015-11-30

    The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The twelfth shipment of samples was designated to include 3H evaporator system Tank 30, 32, and 37 depth samples. The Tank 30 depth sample (HTF-30-15-70) was taken at 190 inches from the tank bottom and the Tank 32 depth sample (HTF-32-15-68) was taken at 89 inches from the tank bottom and both were shipped to SRNL on June 29, 2015 in an 80 mL stainless steel dip bottles. The Tank 37 surface sample (HTF-37-15-94) was taken around 253.4 inches from the tank bottom and shipped to SRNL on July 21, 2015 in an 80 mL stainless steel dip bottle. All samples were placed in the SRNL Shielded Cells and left unopened until intermediate dilutions were made on July 24, 2015 using 1.00 mL of sample diluted to 100.00 mL with deionized H2O. A 30 mL Teflon® bottle was rinsed twice with the diluted tank sample and then filled leaving as little headspace as possible. It was immediately removed from the Shielded Cells and transferred to refrigerated storage where it remained at 4 °C until final dilutions were made on October 20. A second portion of the cells diluted tank sample was poured into a shielded polyethylene bottle and transferred to Analytical Development for radiochemical analysis data needed for Hazardous Material Transportation calculations.

  14. Bulk Acoustic Resonator Based on Piezoelectric ZnO Belts

    E-Print Network [OSTI]

    Wang, Zhong L.

    Bulk Acoustic Resonator Based on Piezoelectric ZnO Belts Brent A. Buchine, William L. Hughes, F, a bulk acoustic resonator based on ZnO belts is demonstrated. This device shows a great deal of promise-like geometry, making them ideal candidates as SMR, FBAR, and beam resonators.13 However, handling belts can

  15. Critical Decision 4 (CD-4) Approval Template | Department of...

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

    More Documents & Publications Example BCP Template Critical Decision 2 (CD-2) Approval Template SOW and Key Performance Parameters (KPP) Handbook Final Version 9-30-2014...

  16. STAR-CD es-aftertreatment | Department of Energy

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

    with STAR-CD using Transient Flemelet Models: TIF and TPV Development of Artificial Ash Accelerated Accumulation Test Diesel Particulate Filters: Market Introducution in...

  17. SIXTH QUARTERLY REPORT OF RESEARCH ON CuxS - (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS

    E-Print Network [OSTI]

    Chin, B.L.

    2011-01-01

    for use in experimental photovoltaic cells. Hall mobilityvacuum method for photovoltaic cell fabrication" However,

  18. OPTIMIZATION OF VIRTUAL FRISCH-GRID CdZnTe DETECTOR DESIGNS FOR IMAGING AND SPECTROSCOPY OF GAMMA RAYS.

    SciTech Connect (OSTI)

    BOLOTNIKOV,A.E.; ABDUL-JABBAR, N.M.; BABALOLA, S.; CAMARDA, G.S.; CUI, Y.; HOSSAIN, A.; JACKSON, E.; JACKSON, H.; JAMES, J.R.; LURYI, A.L.; JAMES, R.B.

    2007-08-21

    In the past, various virtual Frisch-grid designs have been proposed for cadmium zinc telluride (CZT) and other compound semiconductor detectors. These include three-terminal, semi-spherical, CAPture, Frisch-ring, capacitive Frisch-grid and pixel devices (along with their modifications). Among them, the Frisch-grid design employing a non-contacting ring extended over the entire side surfaces of parallelepiped-shaped CZT crystals is the most promising. The defect-free parallelepiped-shaped crystals with typical dimensions of 5x5{approx}12 mm3 are easy to produce and can be arranged into large arrays used for imaging and gamma-ray spectroscopy. In this paper, we report on further advances of the virtual Frisch-grid detector design for the parallelepiped-shaped CZT crystals. Both the experimental testing and modeling results are described.

  19. Characterization of electrospray ion-beam-deposited CdSe/ZnS quantum dot thin films from a colloidal solution

    SciTech Connect (OSTI)

    Tani, Yuki; Kobayashi, Satoshi; Kawazoe, Hiroshi

    2008-07-15

    Colloidal semiconductor quantum dot (QD) nanocrystals can be deposited in the form of inorganic thin films using the ion beam direct deposition method. To simultaneously preserve the nanocrystal configuration and remove the organics derived from the ligand and solvent, the authors used an electrospray technique and an ion beam technique. These techniques provided a soft-ionization process to obtain nanocrystalline ions and a collision process to attain a nonequilibrium state of the deposits, respectively. Because of the nature of the soft-ionization process, the electrospray phenomenon resulted in various forms of QD ions that depended on the preparation of the colloidal solution source and spraying conditions. The authors concentrated on finding operational conditions of the system that deposited thin films with reduced organics concentrations by examining the correlation between fast Fourier transform infrared absorption spectroscopy and photoluminescence intensity. The morphology of the deposited films was observed using an atomic force microscope.

  20. Slow crossover in YbXCu4 ,,XAg, Cd, In, Mg, Tl, Zn... intermediate-valence compounds J. M. Lawrence

    E-Print Network [OSTI]

    Lawrence, Jon

    of specific heat (T) C(T)/T, and 4f occupation number nf(T) for the intermediate-valence compounds YbXCu4 (X-Fermi-liquid behavior is neither expected nor observed and the scaling behavior that is ob- served does not reflect of as dispersive or bandlike behavior of the 4f electrons or alternatively as correlations between the 4f electrons

  1. Modification of solid state CdZnTe (CZT) radiation detectors with high sensitivity or high resolution operation

    DOE Patents [OSTI]

    Washington, II, Aaron L; Duff, Martine C; Teague, Lucile C; Burger, Arnold; Groza, Michael

    2014-11-11

    An apparatus and process is provided to illustrate the manipulation of the internal electric field of CZT using multiple wavelength light illumination on the crystal surface at RT. The control of the internal electric field is shown through the polarization in the IR transmission image under illumination as a result of the Pockels effect.

  2. Energy Transfer Dynamics and Dopant Luminescence in Mn-Doped CdS/ZnS Core/Shell Nanocrystals 

    E-Print Network [OSTI]

    Chen, Hsiang-Yun

    2012-11-13

    , and magnetic properties that are potentially useful in light emitting devices, biological imaging, and spintronics.1-8 These properties originate from the exciton-dopant electronic coupling that is stronger than in the bulk due to the confinement...

  3. Simulation, Modeling, and Crystal Growth of Cd0.9Zn0.1Te for Nuclear

    Office of Scientific and Technical Information (OSTI)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System in the CERN SPS (Conference) | SciTechCouplinginvs.

  4. The Pro-Antioxidant Role of Zinc Supplementation in Cadmium-Treated Choroid Plexus 

    E-Print Network [OSTI]

    Francis Stuart, Samantha D.

    2014-05-06

    at both 24 h and 14 d. In another study, Lemna minor (common duckweed) was treated with Cd without or with Zn4. Zinc supplementation decreased lipid and protein oxidation and decreased catalase and peroxidase activities. Omata et al. demonstrated... in higher order animals. Similar to Zn and Hg, Cd is not a “true” transition metal; it does not have partially filled d and f electron shells as transition metals have. Cadmium is found naturally in the earth’s crust, is a minor component of Zn ores...

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

    SciTech Connect (OSTI)

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

    2012-08-15

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

  6. Stimulated electroluminescence emission from n-ZnO/p-GaAs:Zn heterojunctions fabricated by electro-deposition

    SciTech Connect (OSTI)

    Köç, P.; Tekmen, S.; Baltakesmez, A.; Tüzemen, S.; Meral, K.; Onganer, Y.

    2013-12-15

    In this study, n-ZnO thin films were electrochemically deposited on p-GaAs:Zn substrates. The XRD results of ZnO thin films deposited on p-GaAs:Zn substrates at potentials varied from ?0.9 V to ?1.2 V show a strong c-axis (002) orientation and homogeneity. The current-voltage characteristics exhibit rectification, proving a low turn-on voltage and an ideality factor of 4.71. The n-ZnO/p-GaAs heterostructures show blue-white electroluminescence (EL) emission, which is composed of broad emission bands. In addition to these broad peaks, stimulated emission also appear on the top of the spectra due to the multiple reflections from the mirror like surfaces of ZnO-ZnO and ZnO-GaAs interfaces. Besides, three broad photoluminescence (PL) emission peaks have also been observed peaking at respectively around 3.36 eV, 3.28 eV and 3.07 eV generally attributed to the near bandedge emission, the residual donor level and deep level emission due to the localized defects, respectively.

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

    E-Print Network [OSTI]

    Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application on glass substrates by ultrasonic spray pyrolysis, a simple, environmental-friendly and inexpensive method­12]. Compared to other deposition techniques, spray pyrolysis offers several advantages like non-vacuum use

  8. Mechanism of Cation Exchange Process for Epitaxy of Superconducting HgBa2CaCu2O6 Films and Passive Microwave Devices

    E-Print Network [OSTI]

    Zhao, Hua

    2007-12-17

    and the rf JIP3 derived from the IP3 against reduced temperature suggests that the magnetic vortex depinning in HTS materials dominates the microwave nonlinearity at elevated temperatures. These encouraging results have marked Hg-1212 out as a promising...

  9. STM Study of Copper Growth on ZnO(0001)-Zn and ZnO(0001bar)-O Surfaces Lynn Vogel Koplitz, Olga Dulub, and Ulrike Diebold*,

    E-Print Network [OSTI]

    Diebold, Ulrike

    -4 the production of hydro- gen by steam reforming5,6 or decomposition of methanol,7 and the water-gas shift reaction for CO removal from reformed fuels to enable their use in fuel cells.8,9 Similar catalysts have of the interaction of the Cu with ZnO substrate, and the exact role of the ZnO in the catalytic activity of Cu

  10. ZnO/Cu(InGa)Se.sub.2 solar cells prepared by vapor phase Zn doping

    DOE Patents [OSTI]

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

    2007-02-20

    A process for making a thin film ZnO/Cu(InGa)Se.sub.2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se.sub.2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se.sub.2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se.sub.2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se.sub.2.

  11. 1 Managed by UT-Battelle for the U.S. Department of Energy NF/IDS Hg Vessel Layout 30 Jun 09

    E-Print Network [OSTI]

    McDonald, Kirk

    1 Managed by UT-Battelle for the U.S. Department of Energy NF/IDS Hg Vessel Layout 30 Jun 09;3 Managed by UT-Battelle for the U.S. Department of Energy NF/IDS Hg Vessel Layout 30 Jun 09 Cross Section to flow out the front of the cryostat #12;4 Managed by UT-Battelle for the U.S. Department of Energy NF

  12. Metal pollution of river Msimbazi, Tanzania

    SciTech Connect (OSTI)

    Ak'habuhaya, J.; Lodenius, M. )

    1988-01-01

    The Misimbazi River in Dar es Salaam is polluted with industrial, urban and agricultural waste waters. A preliminary investigation on the extent of metal pollution (Hg, Cr, Cu, Zn, Fe, Ni, Cd, Mn, Al) was made from samples of sediments and biological indicators. The metal concentrations were in general low, but some of our results indicated industrial pollution.

  13. Supplementary Document CdSe quantum dot synthesis

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    dots is given as follows. Cadmium oxide, CdO (Acros Org.); oleic acid, OA (JT Baker); 1-octadecene, ODE. The cadmium stock solution has been prepared by mixing CdO, OA and ODE. The mixture is evacuated by raising-type (boron-doped) with a resistivity of 0.1-1 ·cm. The nanopillar diameter is defined by the nanosphere

  14. Enhanced Performance of CdS/CdSe Quantum Dot Cosensitized Solar Cells via Homogeneous Distribution of Quantum Dots in TiO2

    E-Print Network [OSTI]

    Cao, Guozhong

    , simply increasing film thickness did not make significant contribution to improving solar cell efficiencyEnhanced Performance of CdS/CdSe Quantum Dot Cosensitized Solar Cells via Homogeneous Distribution cosensitized solar cells. The CdS and CdSe quantum dots were prepared on TiO2 mesoporous film through

  15. QUANTIFICATION OF LOSSES IN THIN-FILM CdS/CdTe SOLAR CELLS S.H. Demtsu and J.R. Sites

    E-Print Network [OSTI]

    Sites, James R.

    QUANTIFICATION OF LOSSES IN THIN-FILM CdS/CdTe SOLAR CELLS S.H. Demtsu and J.R. Sites Department of Physics, Colorado State University, Fort Collins, CO 80523, USA ABSTRACT Quantification of solar cell Thin-film CdS/CdTe devices have been studied extensively, but some basic underlying properties

  16. Air-gap gating of MgZnO/ZnO heterostructures

    SciTech Connect (OSTI)

    Tambo, T.; Falson, J. Kozuka, Y.; Maryenko, D.; Tsukazaki, A.; Kawasaki, M.

    2014-08-28

    The adaptation of “air-gap” dielectric based field-effect transistor technology to controlling the MgZnO/ZnO heterointerface confined two-dimensional electron system (2DES) is reported. We find it possible to tune the charge density of the 2DES via a gate electrode spatially separated from the heterostructure surface by a distance of 5??m. Under static gating, the observation of the quantum Hall effect suggests that the charge carrier density remains homogeneous, with the 2DES in the 3?mm square sample the sole conductor. The availability of this technology enables the exploration of the charge carrier density degree of freedom in the pristine sample limit.

  17. Strain-dependent photoluminescence behavior in three geometries of CdSe/CdS nanocrystals

    SciTech Connect (OSTI)

    Choi, Charina L; Koski, Kristie J; Sivasankar, Sanjeevi; Alivisatos, A Paul

    2009-05-26

    In recent years, a new generation of quantum confined colloidal semiconductor structures has emerged, with more complex shapes than simple quantum dots1, 2. These include nanorods3 and tetrapods4. Beyond shape, it is also now possible to spatially vary the electron and hole potentials within these nanoparticles by varying the composition. Examples of these new structures include seeded dots, rods, and tetrapods, which contain a CdSe core embedded within a CdS shell5, 6. These structures may have many uses beyond those envisioned for simple quantum dots, which are frequently employed in luminescent applications7. This paper is concerned with changes in the optoelectronic properties of tetrapods when the arms are bent. We demonstrate that seeded tetrapods can serve as an optical strain gauge, capable of measuring forces on the order of nanonewtons. We anticipate that a nanocrystal strain gauge with optical readout will be useful for applications ranging from sensitive optomechanical devices to biological force investigations.

  18. Electrical resistivity of Au-ZnO nanocomposite films

    SciTech Connect (OSTI)

    Argibay, N.; Goeke, R. S.; Dugger, M. T.; Rodriguez, M. A.; Michael, J. R.; Prasad, S. V. [Materials Science and Engineering Center, Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)

    2013-04-14

    The electrical resistivity of electron beam codeposited gold and zinc oxide (Au-ZnO) films was investigated over the full composition range. The electrical resistivity was shown to increase monotonically with increasing ZnO content, with three characteristic regimes of behavior associated primarily with (1) grain boundary electron scattering due to grain refinement at ZnO volume fractions below 0.3, (2) percolation theory for ZnO volume fractions at and above the percolation threshold (f{sub c} = 0.85), and (3) a transition region between these where it was proposed that resistivity was influenced by the formation of Au-Zn complexes due to an oxygen deficiency in the deposited ZnO. The electrical resistivity of the composite films remained below 100 {mu}{Omega} cm for ZnO volume fractions below 0.5. A model combining the general effective media equation and Mayadas-Shatzkes grain boundary electron scattering model was shown to generally describe the composition dependence of electrical resistivity for the investigated oxide dispersion hardened metal-matrix composite thin films.

  19. Radioactive contamination of ZnWO4 crystal scintillators

    E-Print Network [OSTI]

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

    2010-09-05

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

  20. Native defects in MBE-grown CdTe

    SciTech Connect (OSTI)

    Olender, Karolina; Wosinski, Tadeusz; Makosa, Andrzej; Tkaczyk, Zbigniew; Kolkovsky, Valery; Karczewski, Grzegorz

    2013-12-04

    Deep-level traps in both n- and p-type CdTe layers, grown by molecular-beam epitaxy on GaAs substrates, have been investigated by means of deep-level transient spectroscopy (DLTS). Four of the traps revealed in the DLTS spectra, which displayed exponential kinetics for capture of charge carriers into the trap states, have been assigned to native point defects: Cd interstitial, Cd vacancy, Te antisite defect and a complex formed of the Te antisite and Cd vacancy. Three further traps, displaying logarithmic capture kinetics, have been ascribed to electron states of treading dislocations generated at the mismatched interface with the substrate and propagated through the CdTe layer.

  1. The effects of fabrication temperature on current-voltage characteristics and energy efficiencies of quantum dot sensitized ZnOH-GO hybrid solar cells

    SciTech Connect (OSTI)

    Islam, S. M. Z.; Gayen, Taposh; Tint, Naing; Alfano, Robert; Shi, Lingyan; Seredych, Mykola; Bandosz, Teresa J.

    2014-11-07

    The effects of fabrication temperature are investigated on the performance of CdSe quantum dot (QD)-sensitized hybrid solar cells of the composite material of zinc (hydr)oxide (ZnOH-GO)with 2?wt.?% graphite oxide. The current-voltage (I-V) and photo-current measurements show that higher fabrication temperatures yield greater photovoltaic power conversion efficiencies that essentially indicate more efficient solar cells. Two Photon Fluorescence images show the effects of temperature on the internal morphologies of the solar devices based on such materials. The CdSe-QD sensitized ZnOH-GO hybrid solar cells fabricated at 450?°C showing conversion of ?10.60% under a tungsten lamp (12.1 mW/cm{sup 2}) are reported here, while using potassium iodide as an electrolyte. The output photocurrent, I (?A) with input power, P (mW/cm{sup 2}) is found to be superlinear, showing a relation of I?=?P{sup n}, where n?=?1.4.

  2. Dopant-induced band filling and bandgap renormalization in CdO:In films

    E-Print Network [OSTI]

    Zhu, Yuankun

    2014-01-01

    measurements on boron-doped CdO thin films J. Mater. Sci.electrical properties of In-doped CdO thin films fabricatedthe optical bandgap in doped CdO since the conduction band

  3. Primary cutaneous CD30+ large-cell lymphoma presenting as a scrotal plaque

    E-Print Network [OSTI]

    Modi, Sapna; Yang, Deborah J; Sule, Norman; Rosen, Ted

    2009-01-01

    studies have shown that CD30 negative LCLs have a worseprognosis than CD30+ LCLs [ 4 , 8 ] and should be treatedfrom some primary cutaneous CD30+ LCLs, making the clinical

  4. The CD36, CLA-1(CD36L1), and LIMPII (CD36L2) gene family: Cellular distribution, chromosomal location, and genetic evolution

    SciTech Connect (OSTI)

    Calvo, D.; Vega, M.A.; Dopazo, J.

    1995-01-01

    CD36, CLA-1, and LIMPII are single polypeptide membrane glycoproteins, and the genes encoding them constitute a recently described gene family. In the present paper, a cDNA encoding the human lysosomal membrane protein LIMPII was used to determine its expression pattern in cells of various lineages. Like CLA-1, and in contrast with the restricted expression of CD36, the expression of LIMPII is widespread. Mapping of the human LIMPII and CLA-1 genes (gene symbols CD36L2 and CD36L1, respectively) to specific chromosomes revealed that CLA-1, LIMPII, and CD36 do not form a gene cluster, but are found dispersed on chromosomes 12, 4, and 7, respectively. These data, together with the phylogenetic analysis carried out for the members of this family, indicate that the LIMPII, CIA-1, and CD36 genes diverged early in evolution from an ancestor gene, possibly before the divergence between the arthropods and the vertebrates. 48 refs., 5 figs.

  5. Fate of Cd during Microbial Fe(III) Mineral Reduction by a Novel and Cd-Tolerant Geobacter Species

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    , potentially altering the dynamics of Cd uptake into food or phyto-remediating plants. INTRODUCTION The heavy atmospheric deposition and fertilization.7-9 Cd binds to clays, carbonates, organic matter, and Fe oxides via ternary complexes with organic matter.14 Several studies have investigated sorption mechanisms

  6. COMPARISON OF CSS-CdTe AND PVD-CdTe WITH DIFFERENT ACTIVATION PROCESSES , G. Khrypunov2,4

    E-Print Network [OSTI]

    Romeo, Alessandro

    Energy Systems and Technology), Department of Electronic and Electrical Engineering, Loughborough) system at lower substrate temperatures (typically 300°C) has also provided solar cells with efficienciesCOMPARISON OF CSS-CdTe AND PVD-CdTe WITH DIFFERENT ACTIVATION PROCESSES A. Romeo1 , G. Khrypunov2

  7. Electrodeposition of zinc on glassy carbon from ZnCl/sub 2/ and ZnBr/sub 2/ electrolytes

    SciTech Connect (OSTI)

    McBreen, J.; Gannon, E.

    1983-08-01

    The initial stages of the electrocrystallization of zinc from 3M ZnCl/sub 2/ and 3M ZnBr/sub 2/ on glassy carbon has been investigated using cyclic voltametry, the potential step method, and scanning electron microscopy. Particular care was taken to ensure electrolyte purity and to eliminate resistance effects in the measurements. The nucleation overvoltage in 3M ZnCl/sub 2/ was about 17 and about 12 mV in 3M ZnBr/sub 2/. In 3M ZnCl/sub 2/, the current transients from the potential step measurements could be fitted to a simple model that assumes instantaneous nucleation followed by growth of three dimensional centers under kinetic control. A similar mechanism is operative for 3M ZnBr/sub 2/ at low overvoltages. At higher overvoltages, the current transient is governed by mixed kinetic and diffusion control and cannot be fitted to a simple model. The lower nucleation overvoltage and the faster kinetics in 3M ZnBr/sub 2/ is correlated with the lower stability constants for the zinc bromide complexes. Erroneous results are obtained when resistance effects are not accounted for.

  8. Nuclear structure ''southeast'' of {sup 208}Pb: Isomeric states in {sup 208}Hg and {sup 209}Tl

    SciTech Connect (OSTI)

    Al-Dahan, N. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, University of Kerbala, Kerbala (Iraq); Podolyak, Zs.; Regan, P. H.; Alkhomashi, N.; Deo, A. Y.; Farrelly, G.; Steer, S. J.; Cullen, I. J.; Gelletly, W.; Swan, T.; Thomas, J. S.; Walker, P. M. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Gorska, M.; Grawe, H.; Gerl, J.; Pietri, S. B.; Wollersheim, H. J.; Boutachkov, P.; Domingo-Pardo, C.; Farinon, F. [GSI, D-64291 Darmstadt (Germany)] (and others)

    2009-12-15

    The nuclear structure of neutron-rich N>126 nuclei has been investigated following their production via relativistic projectile fragmentation of a E/A=1 GeV {sup 238}U beam. Metastable states in the N=128 isotones {sup 208}Hg and {sup 209}Tl have been identified. Delayed {gamma}-ray transitions are interpreted as arising from the decay of I{sup {pi}}=(8{sup +}) and (17/2{sup +}) isomers, respectively. The data allow for the so far most comprehensive verification of the shell-model approach in the region determined by magic numbers Z<82 and N>126.

  9. Hot exciton transport in ZnSe quantum wells

    E-Print Network [OSTI]

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

    2002-02-01

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

  10. DIRECT EVIDENCE OF MG-ZN-P ALLOY FORMATION IN MG/ZN3P2 SOLAR CELLS Gregory M. Kimball

    E-Print Network [OSTI]

    Kimball, Gregory

    Te, CIGS, a-Si) for thin film photovoltaics. The record solar energy conversion efficiency for Zn3P2 cellsDIRECT EVIDENCE OF MG-ZN-P ALLOY FORMATION IN MG/ZN3P2 SOLAR CELLS Gregory M. Kimball 1 , Nathan S indicate that high efficiency should be realizable by optimization of Mg treatment in Mg/Zn3P2 solar cells

  11. Process Development for High Voc CdTe Solar Cells

    SciTech Connect (OSTI)

    Ferekides, C. S.; Morel, D. L.

    2011-05-01

    This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

  12. 'Giant' multishell CdSe nanocrystal quantum dots with supporessed blinking: novel fluorescent probes for real-time detection of single-molecule events

    SciTech Connect (OSTI)

    Hollingsworth, Jennifer A; Vela, Javier; Htoon, Han; Klimov, Victor I; Casson, Amy R; Chen, Yongfen

    2009-01-01

    We reported for the first time that key nanocrystal quantum dot (NQD) optical properties-quantum yield, photobleaching and blinking-can be rendered independent ofNQD surface chemistry and environment by growth of a very thick, defect-free inorganic shell. Here, we show the precise shell-thickness dependence of these effects. We demonstrate that 'giant-shell' NQDs can be largely non-blinking for observation times as long as 54 minutes and lhat on-time fractions are independent of experimental time-resolution from 1-200 ms. These effects are primarily demonstrated on (CdSe)CdS (core)shell NQDs, but we also show that alloyed shells comprising Cd.Znl.'S and terminated with a non-cytotoxic ZnS layer exhibit similar properties. The mechanism for suppressed blinking and dramatically enhanced stability is attributed to both effective isolation of the NQD core excitonic wavefunction from the NQD surface, as well as a quasi-Type II electronic structure. The unusual electronic structure provides for effective spatial separation of the electron and hole into the shell and core, respectively, and, thereby, for reduced efficiencies in non-radiative Auger recombination.

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

    E-Print Network [OSTI]

    Iglesia, Enrique

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

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

    SciTech Connect (OSTI)

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

    2013-10-15

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

  15. Optical Properties of CdSe Nanoparticle Assemblies

    SciTech Connect (OSTI)

    Huser, T; Gerion, D; Zaitseva, N; Krol, D M; Leon, F R

    2003-11-24

    We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.

  16. Nanoparticulate PdZn as a Novel Catalyst for ZnO Nanowire Growth

    E-Print Network [OSTI]

    2010-03-14

    at 500?C (see below). The prepared grids were dip coated with a methanol suspension of PdZn colloid (molar metal ratio 50:50) with a total metal concentration of 0.490 mg/ml. As a control sample, a silicon wafer was coated with particles under the same... at temperatures ranging from 560 to 820?C. An Ar/O2 mixture was used as the carrier gas. Subsequent analyses were carried out by both HRSEM and HRTEM along with EDS and SAED. An overview of the parameter combinations investigated is shown in Table 1. Selected...

  17. The effect of irradiation with electrons on the electrical parameters of Hg{sub 3}In{sub 2}Te{sub 6}

    SciTech Connect (OSTI)

    Grushka, O. G., E-mail: semicon-dpt@chnu.edu.ua [Fedkovich Chernovtsy National University (Ukraine); Maslyuk, V. T. [Ukrainian Academy of Sciences, Institute of Electron Physics (Ukraine); Chupyra, S. M.; Mysliuk, O. M.; Bilichuk, S. V.; Zabolotskiy, I. I. [Fedkovich Chernovtsy National University (Ukraine)

    2012-03-15

    The results of studying the electrical properties of Hg{sub 3}In{sub 2}Te{sub 6} crystals irradiated with electrons with the energy E{sub e} = 18 MeV and the dose D = 4 Multiplication-Sign 10{sup 16} cm{sup -2} are reported. It is shown that, irrespective of the charge-carrier concentration in the initial material, the Hg{sub 3}In{sub 2}Te{sub 6} samples acquire the charge-carrier concentration (1.6-1.8) Multiplication-Sign 10{sup 13} cm{sup -3} after irradiation. The phenomenon of Fermi level pinning in an irradiated material is discussed. The initial charge-carrier concentration, which remains virtually unchanged after irradiation and which ensures the high radiation resistance of Hg{sub 3}In{sub 2}Te{sub 6} crystals, corresponds to a compensated material, similar to an intrinsic semiconductor at T > 260 K.

  18. Advances in Brief CD40 Is Expressed on Ovarian Cancer Cells and Can Be Utilized

    E-Print Network [OSTI]

    Hemminki, Akseli

    Advances in Brief CD40 Is Expressed on Ovarian Cancer Cells and Can Be Utilized for Targeting: According to our studies, all of the examined ovarian cancer cell lines are expressing CD40. In addition, m for CD40. Conclusions: These results suggest that CD40 is present in ovarian cancer cells and can be used

  19. A review of trace element emissions from the combustion of refuse-derived fuel with coal

    SciTech Connect (OSTI)

    Norton, G.A. )

    1992-05-01

    The effects of cocombusting refuse-derived fuel (RDF) with coal on stack emissions of trace elements in the ash stream were reviewed. The large number of variables and uncertainties involved precluded drawing definitive conclusions regarding many of the trace elements. However, it is evident that cocombustion resulted in increased emissions of Cd, Cu, Hg, Pb, and Zn. Emissions of As and Ni tended to decrease when RDF was fired with coal. Modeling studies indicated that ambient levels of trace elements during cocombustion should be within acceptable limits. However, periodic monitoring of Cd, Hg, and Pb may be warranted in some instances.

  20. Activation of tolerogenic dendritic cells in the tumor draining lymph CD8+ T cells engineered to express CD40 ligand

    E-Print Network [OSTI]

    Higham, Eileen M.

    Tolerogenic dendritic cells in the tumor microenvironment can inhibit the generation and maintenance of robust antitumor T cell responses. In this study, we investigated the effects of local delivery of CD40L by tumor-reactive ...

  1. Synthesis, characterization and optical properties of hybrid PVA–ZnO nanocomposite: A composition dependent study

    SciTech Connect (OSTI)

    Hemalatha, K.S. [Department of Physics, Bangalore University, Bangalore 560 056, Karnataka (India); Department of Physics, Maharani's Science College for Women, Palace Road, Bangalore 560 001, Karnataka (India); Rukmani, K., E-mail: rukmani9909@yahoo.co.in [Department of Physics, Bangalore University, Bangalore 560 056, Karnataka (India); Suriyamurthy, N. [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Nagabhushana, B.M. [Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, Karnataka (India)

    2014-03-01

    Graphical abstract: - Highlights: • ZnO nanoparticles were prepared by solution combustion method. • PVA–ZnO nanocomposites were synthesized by solution casting method. • Doped and undoped films were characterized using different techniques. • Red shift in optical band gap was observed in Nanocomposite films with respect to nano ZnO. • Photoluminescence intensity was found to be optimum for PVA–10 mol% ZnO nanocomposite film. - Abstract: Nanocomposites of poly vinyl alcohol (PVA) and ZnO have been synthesized using the solution casting technique for different concentrations of nano ZnO powder prepared by low temperature solution combustion method. The formation of polymer nanocomposite and changes in the structural and micro structural properties of the materials were investigated by X-ray diffraction, Energy dispersive X ray spectroscopy and optical microscopy techniques (FTIR and UV–Visible). The surface morphology of PVA–ZnO nanocomposite films were elucidated using Scanning Electron Microscopy. The optical absorption spectrum of nano ZnO shows blue shift in the optical band gap energy with respect to characteristic bulk ZnO at room temperature, whereas PVA–ZnO hybrid films show red shift with respect to nano ZnO. The photoluminescence studies show that the intensity of the blue emission (470 nm) varies with change in concentration of ZnO with an optimum intensity observed at 10 mol% of ZnO.

  2. Identification and decay of the 0.48 ms 13/2{sup +} isomer in {sup 181}Hg

    SciTech Connect (OSTI)

    Andreyev, A. N.; Antalic, S.; Saro, S.; Ackermann, D.; Comas, V. F.; Heinz, S.; Heredia, J. A.; Hessberger, F. P.; Khuyagbaatar, J.; Kojouharov, I.; Kindler, B.; Lommel, B.; Mann, R.; Cocolios, T. E.; Elseviers, J.; Huyse, M.; Duppen, P. Van; Venhart, M.; Franchoo, S.; Hofmann, S.

    2009-10-15

    A new isomer with a half-life of 0.48(2) ms was identified in the nuclide {sup 181}Hg, which was produced in the complete fusion reaction {sup 40}Ca+{sup 144}Sm{yields}{sup 184}Pb* at the velocity filter SHIP (GSI, Darmstadt). The isomeric state was tentatively assigned a spin-parity of 13/2{sup +}. We propose that this isomer de-excites by a yet unobserved low-energy, strongly converted {gamma}-ray transition, followed by a newly identified cascade composed of a 90.3 keV M1 and a 71.4 keV E2 {gamma}-ray transition.

  3. Measurement of a false electric dipole moment signal from $^{199}$Hg atoms exposed to an inhomogeneous magnetic field

    E-Print Network [OSTI]

    S. Afach; C. A. Baker; G. Ban; G. Bison; K. Bodek; Z. Chowdhuri; M. Daum; M. Fertl; B. Franke; P. Geltenbort; K. Green; M. G. D. van der Grinten; Z. Grujic; P. G. Harris; W. Heil; V. Hélaine; R. Henneck; M. Horras; P. Iaydjiev; S. N. Ivanov; M. Kasprzak; Y. Kermaïdic; K. Kirch; P. Knowles; H. -C. Koch; S. Komposch; A. Kozela; J. Krempel; B. Lauss; T. Lefort; Y. Lemière; A. Mtchedlishvili; O. Naviliat-Cuncic; J. M. Pendlebury; F. M. Piegsa; G. Pignol; P. N. Prashant; G. Quéméner; D. Rebreyend; D. Ries; S. Roccia; P. Schmidt-Wellenburg; N. Severijns; A. Weis; E. Wursten; G. Wyszynski; J. Zejma; J. Zenner; G. Zsigmond

    2015-08-03

    We report on the measurement of a Larmor frequency shift proportional to the electric-field strength for $^{199}{\\rm Hg}$ atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the inevitable magnetic field gradients and the motional magnetic field. The proportionality to electric-field strength makes it apparently similar to an electric dipole moment (EDM) signal, although unlike an EDM this effect is P- and T-conserving. We have used a neutron magnetic resonance EDM spectrometer, featuring a mercury co-magnetometer and an array of external cesium magnetometers, to measure the shift as a function of the applied magnetic field gradient. Our results are in good agreement with theoretical expectations.

  4. Diffusion of Cd vacancy and interstitials of Cd, Cu, Ag, Au and Mo in CdTe: A first principles investigation

    E-Print Network [OSTI]

    Khare, Sanjay V.

    Te) based thin film technology has emerged as a leader in the growing market of thin film solar cell module as an absorber material in thin film solar cells. The relatively high chemical stability of CdTe compared; Structural properties; Energetic properties 1. Introduction Recent advancements in thin film technology have

  5. Phase instability and defect induced evolution of optical properties in Cd rich-CdS nanoparticles

    SciTech Connect (OSTI)

    Chandran, Anoop; George, K. C., E-mail: drkcgeorge@gmail.com [Department of Physics, S B College, Changanassery, Kerala 686101 (India)

    2014-04-28

    Although semiconductor nanostructures exhibit improved physical properties, their structural instability is be a problem for technological applications. This paper reports a temperature-induced low energy phase transformation that occurs in CdS nanoparticles which is ascribed to thermally generated stacking-faults. The phase transformation is found to change the nature of lattice strain in the samples. The formation of this defect-induced lattice strain and its influence on the physical properties of the samples are investigated. The modified optical absorption and emission properties of the samples are thoroughly studied. Using resonance Raman spectroscopy, the evolution of electron-phonon (e-p) coupling strength with structural changes is studied. An explanation to the contradictory nature of e-p coupling strength observed in the nano-regime is given.

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

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

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

  7. Tuning of defects in ZnO nanorod arrays used in bulk heterojunction solar cells

    E-Print Network [OSTI]

    Iza, Diana C; Muñoz-Rojas, David; Jia, Quanxi; Swartzentruber, Brian; MacManus-Driscoll, Judith L

    2012-11-27

    Abstract With particular focus on bulk heterojunction solar cells incorporating ZnO nanorods, we study how different annealing environments (air or Zn environment) and temperatures impact on the photoluminescence response. Our work gives new insight...

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

    E-Print Network [OSTI]

    Wong, Brian Alexander

    2009-01-01

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

  9. One-step electrochemical synthesis of a graphene–ZnO hybrid for improved photocatalytic activity

    SciTech Connect (OSTI)

    Wei, Ang; Xiong, Li; Sun, Li; Liu, Yanjun; Li, Weiwei; Lai, Wenyong; Liu, Xiangmei; Wang, Lianhui; Huang, Wei; Dong, Xiaochen

    2013-08-01

    Graphical abstract: - Highlights: • Graphene–ZnO hybrid was synthesized by one-step electrochemical deposition. • Graphene–ZnO hybrid presents a special structure and wide UV–vis absorption spectra. • Graphene–ZnO hybrid exhibits an exceptionally higher photocatalytic activity for the degradation of dye methylene blue. - Abstract: A graphene–ZnO (G-ZnO) hybrid was synthesized by one-step electrochemical deposition. During the formation of ZnO nanostructure by cathodic electrochemical deposition, the graphene oxide was electrochemically reduced to graphene simultaneously. Scanning electron microscope images, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectra, and UV–vis absorption spectra indicate the resulting G-ZnO hybrid presents a special structure and wide UV–vis absorption spectra. More importantly, it exhibits an exceptionally higher photocatalytic activity for the degradation of dye methylene blue than that of pure ZnO nanostructure under both ultraviolet and sunlight irradiation.

  10. A Reinterpretation of the Mechanism of the Simplest Reaction at an -Hybridized Carbon Atom: H + CD4 f CD3 + HD

    E-Print Network [OSTI]

    Zare, Richard N.

    ,11 we measure the center of mass differential cross-section (DCS) of the CD3()0) products for Ecoll + CD4 f CD3 + HD Jon P. Camden, Hans A. Bechtel, Davida J. Ankeny Brown, Marion R. Martin, Richard N, but the small reaction cross-section has made state-to- state resolved dynamics experiments difficult, and few

  11. Nitrogen is a deep acceptor in ZnO

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

    Tarun, M. C.; Iqbal, M. Zafar; McCluskey, M. D.

    2011-04-14

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

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

    E-Print Network [OSTI]

    Boyer, Edmond

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

  13. Effect of ZnO seed layer on the morphology and optical properties of ZnO nanorods grown on GaN buffer layers

    SciTech Connect (OSTI)

    Nandi, R. Mohan, S. Major, S. S.; Srinivasa, R. S.

    2014-04-24

    ZnO nanorods were grown by chemical bath deposition on sputtered, polycrystalline GaN buffer layers with and without ZnO seed layer. Scanning electron microscopy and X-ray diffraction show that the ZnO nanorods on GaN buffer layers are not vertically well aligned. Photoluminescence spectrum of ZnO nanorods grown on GaN buffer layer, however exhibits a much stronger near-band-edge emission and negligible defect emission, compared to the nanorods grown on ZnO buffer layer. These features are attributed to gallium incorporation at the ZnO-GaN interface. The introduction of a thin (25 nm) ZnO seed layer on GaN buffer layer significantly improves the morphology and vertical alignment of ZnO-NRs without sacrificing the high optical quality of ZnO nanorods on GaN buffer layer. The presence of a thick (200 nm) ZnO seed layer completely masks the effect of the underlying GaN buffer layer on the morphology and optical properties of nanorods.

  14. SNS Target Test Facility: Prototype Hg Operations and Remote Handling Tests P. T. Spampinato, T. W. Burgess, J. B. Chesser, V. B. Graves, and S.L. Schrock

    E-Print Network [OSTI]

    McDonald, Kirk

    SNS Target Test Facility: Prototype Hg Operations and Remote Handling Tests P. T. Spampinato, T. W Neutron Source, Target Test Facility is a full-scale replica of the mercury-target flow loop prototypic target, and numerous pressure sensors. Outside of the loop enclosure, tests were done on a new

  15. Results of Hg speciation testing on 3Q15 tank 50, salt solution feed tank (SSFT), and solvent hold tank (SHT) materials

    SciTech Connect (OSTI)

    Bannochie, C.

    2015-08-13

    The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The results are documented in this report.

  16. Structure of graphene oxide dispersed with ZnO nanoparticles

    SciTech Connect (OSTI)

    Yadav, Rishikesh Pandey, Devendra K.; Khare, P. S.

    2014-10-15

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

  17. Room-temperature larger-scale highly ordered nanorod imprints of ZnO film

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    ordered nanorod-patterned ZnO films directly integrated on III-nitride light-emitting diodes (LEDs nm in height continuous ZnO wetting layer, the light output power of the resulting integrated ZnO-nanorod-film/semi-transparent metal/GaN/InGaN LED shows a two-fold enhancement (100% light extraction efficiency improvement

  18. Hydrogen-related defects in bulk ZnO Matthew D. McCluskey,1

    E-Print Network [OSTI]

    McCluskey, Matthew

    Hydrogen-related defects in bulk ZnO Matthew D. McCluskey,1 Slade J. Jokela,1 and Marianne C. Tarun. This paper reviews recent work on hydrogen donors and nitrogen-hydrogen complexes in ZnO. INTRODUCTION Zinc be understood. One such defect is hydrogen, a common impurity in ZnO. We have studied hydrogen donors using

  19. Precipitation and mechanical properties of supersaturated Al-Zn-Mg alloys processed by severe plastic deformation

    E-Print Network [OSTI]

    Gubicza, Jenõ

    Precipitation and mechanical properties of supersaturated Al-Zn-Mg alloys processed by severe density, precipitation. Abstract. Supersaturated Al-4.8Zn-1.2Mg-0.14Zr and Al-5.7Zn-1.9Mg-0.35Cu (wt distribution and the characteristic parameters of the dislocation structure of both Al matrix and precipitates

  20. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells. Final subcontract report, 1 July 1988--31 December 1991

    SciTech Connect (OSTI)

    Chu, T.L.

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  1. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells

    SciTech Connect (OSTI)

    Chu, T.L. )

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  2. CD-3: Crystalline Rock - Basement | Open Energy Information

    Open Energy Info (EERE)

    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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank, Maine:Kansas: Energy Resources Jump to:Energy Inc -6CCC Federal2CD-2:CD-3:

  3. Growth, steady-state, and time-resolved photoluminescence study of CdTe/MgCdTe double heterostructures on InSb substrates using molecular beam epitaxy

    SciTech Connect (OSTI)

    DiNezza, Michael J.; Liu, Shi; Kirk, Alexander P.; Zhang, Yong-Hang [Center for Photonics Innovation, Arizona State University, Tempe, Arizona 85287 (United States) [Center for Photonics Innovation, Arizona State University, Tempe, Arizona 85287 (United States); School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Zhao, Xin-Hao [Center for Photonics Innovation, Arizona State University, Tempe, Arizona 85287 (United States) [Center for Photonics Innovation, Arizona State University, Tempe, Arizona 85287 (United States); School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)

    2013-11-04

    CdTe/MgCdTe double heterostructures (DHs) are grown on InSb substrates using molecular beam epitaxy and reveal strong photoluminescence with over double the intensity of a GaAs/AlGaAs DH with an identical layer structure design grown on GaAs. Time-resolved photoluminescence of the CdTe/MgCdTe DH gives a Shockley-Read-Hall recombination lifetime of 86 ns, which is more than one order of magnitude longer than that of typical polycrystalline CdTe films. These findings indicate that monocrystalline CdTe/MgCdTe DHs effectively reduce surface recombination, have limited nonradiative interface recombination, and are promising for solar cells that could reach power conversion efficiencies similar to that of GaAs.

  4. The 106Cd(alpha,alpha)106Cd elastic scattering in a wide energy range for gamma-process studies

    E-Print Network [OSTI]

    A. Ornelas; G. G. Kiss; P. Mohr; D. Galaviz; Zs. Fülöp; Gy. Gyürky; Z. Máté; T. Rauscher; E. Somorjai; K. Sonnabend; A. Zilges

    2015-04-29

    Alpha elastic scattering angular distributions of the 106Cd(alpha,alpha)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the alpha + nucleus optical potential parameter sets. Furthermore, the new high precision angular distributions, together with the data available from the literature were used to study the energy dependence of the locally optimized {\\alpha}+nucleus optical potential in a wide energy region ranging from E_Lab = 27.0 MeV down to 16.1 MeV. The potentials under study are a basic prerequisite for the prediction of alpha-induced reaction cross sections and thus, for the calculation of stellar reaction rates used for the astrophysical gamma process. Therefore, statistical model predictions using as input the optical potentials discussed in the present work are compared to the available 106Cd + alpha cross section data.

  5. Defect Chemistry Study of Nitrogen Doped ZnO Thin Films

    SciTech Connect (OSTI)

    Miami University: Dr. Lei L. Kerr Wright State University: Dr. David C. Look and Dr. Zhaoqiang Fang

    2009-11-29

    Our team has investigated the defect chemistry of ZnO:N and developed a thermal evaporation (vapor-phase) method to synthesis p-type ZnO:N. Enhanced p-type conductivity of nitrogen doped ZnO via nano/micro structured rods and Zn-rich Co-doping process were studied. Also, an extended X-Ray absorption fine structure study of p-type nitrogen doped ZnO was conducted. Also reported are Hall-effect, photoluminescence, and DLTS studies.

  6. The Nature of Zn Precipitates Formed in the Presence of

    E-Print Network [OSTI]

    Sparks, Donald L.

    D D O N A L D L . S P A R K S Department of Plant and Soil Sciences, University of Delaware, NewarkThe Nature of Zn Precipitates Formed in the Presence of Pyrophyllite R O B E R T G . F O R D * A N

  7. ZnO Nanotube Based Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

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

  8. Seven-year performance of eucalyptus speczes zn

    E-Print Network [OSTI]

    Seven-year performance of eucalyptus speczes zn Napa County Dean R. Donaldson o John W. LeBlanc o RichardB. Standiford SherriGallagher LI CharlesJ. Jourdain o George E. Miller Eucalyptus was promoted to sour on the purported "miracle tree" when it became evident that eucalyptus grown in California

  9. Strain-Dependent Photoluminescence Behavior of CdSe/CdS Nanocrystals with Spherical, Linear, and Branched Topologies

    SciTech Connect (OSTI)

    Choi, Charina L.; Koski, Kristie J.; Sivasankar, Sanjeevi; Alivisatos, A. Paul

    2009-08-13

    The photoluminescence of CdSe/CdS core/shell quantum dots, nanorods, and tetrapods is investigated as a function of applied hydrostatic and non-hydrostatic pressure. The optoelectronic properties of all three nanocrystal morphologies are affected by strain. Furthermore, it is demonstrated that the unique morphology of a tetrapod is highly sensitive to non-isotropic stress environments. Seeded tetrapods can thereby serve as an optical strain gauge, capable of measuring forces on the order of nanonewtons. We anticipate that a nanocrystal strain gauge with optical readout will be useful for applications ranging from sensitive optomechanical devices to investigations of biomechanical processes.

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

    E-Print Network [OSTI]

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

    2015-01-01

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

  11. INFORMATICA CdL in Scienze e Tecniche Psicologiche

    E-Print Network [OSTI]

    Sproston, Jeremy

    INFORMATICA CdL in Scienze e Tecniche Psicologiche Introduzione Il corso di Informatica (Di cosa parliamo?) 1 Il docente · Jeremy Sproston · Ufficio presso il Dipartimento di Informatica, via Pessinetto. Carmagnola, F. Cena, Introduzione all'informatica (4 ed), UTET libreria, Torino, 2010 · Altre letture utile

  12. C.D. Howe Institute Taxing Emissions, Not Income

    E-Print Network [OSTI]

    C.D. Howe Institute COMMENTARY Taxing Emissions, Not Income: How to Moderate the Regional Impact... If policymakers wish to reduce Canadian greenhouse gas emissions, they can do so using a suite of policy tools dioxide and other GHG emissions. However, policymakers have yet to take such action because of concerns

  13. Original article Short-term in situ immobilization of Cd

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    addition, the extractabil- ity in calcium nitrate (0.1 M) and the plant availability of soil-Cd and -Ni/Elsevier, Paris.) sewage sludge / cadmium / nickel / immobilization / soil-plant transfer Résumé - Immobilisation pre- miers cm d'un sol pollué par des métaux. Un an après leurs apports, des extractions au nitrate de

  14. Microfluidics for biological analysis: Triumphs and hurdles of CD platforms

    E-Print Network [OSTI]

    Giri, Ranjit K.

    Microfluidics for biological analysis: Triumphs and hurdles of CD platforms JONATHAN SIEGRIST1 , R on microfluidic technologies has become extensive, particularly in regards to the develop- ment of sample. Centrifugal microfluidic platforms based on the compact-disc format are discussed, along with the advantages

  15. The UNEP project CD4CDM Guidebook to

    E-Print Network [OSTI]

    months, with more than 1,700 projects in the pipeline by March 2007. However, CDM project development numerous CDM project concepts never materialise. This has been the case especially for Africa and for otherThe UNEP project CD4CDM Guidebook to Financing CDM Projects #12;Guidebook to Financing CDM Projects

  16. Population of low-seniority isomeric states of {sup 206}Hg by two-proton knockout reactions at relativistic energies

    SciTech Connect (OSTI)

    Simpson, E. C.; Tostevin, J. A.; Podolyak, Zs.; Regan, P. H.; Steer, S. J. [Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2009-12-15

    We consider calculations of direct two-proton removal reactions from a relativistic-energy {sup 208}Pb beam incident on a {sup 9}Be target, leading to the population of two-proton-hole isomeric configurations in {sup 206}Hg. The calculated 5{sup -} and 10{sup +} isomeric state population ratios of 18.8% and 4.7%, respectively, are in fair agreement with the values deduced experimentally (21.9{sub -2.9}{sup +1.2}% and 3.1{sub -1.2}{sup +1.0}%); however, the high density of final states in this case complicates the prediction of isomeric ratios for those states fed by unobserved prompt {gamma}-ray cascades. We also consider and quantify the effects of selection of events, according to the longitudinal momenta of the reaction residues, on the measured isomeric ratios for high-spin final states and, hence, of the potential to exploit such sensitivity to gain further insight into the reaction mechanism.

  17. Results of Hg speciation testing on MCU strip effluent hold tank (SEHT) and decontaminated salt solution hold tank (DSSHT) materials

    SciTech Connect (OSTI)

    Bannochie, C. J.

    2015-09-17

    The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team.i,ii The tenth shipment of samples was designated to include Modular Caustic Side Solvent Extraction Unit (MCU) Strip Effluent Hold Tank (SEHT) and MCU Decontaminated Salt Solution Hold Tank (DSSHT) materials from processing Salt Batch 7b. The MCU SEHT (MCU-15-722) and DSSHT (MCU-15-709) samples were pulled on June 15, 2015. All MCU samples were received at SRNL on June 16, 2015. The DSSHT sample was moved the same day to refrigeration, while the SEHT sample was placed in the Shielded Cells. On July 9, 2015 it was opened and an aliquot diluted 1:100 with Eurofins deionized water and a portion of the diluted sample transferred to a Teflon® bottle prior to moving it to refrigeration that same day. All samples were kept in the dark and refrigerated until final dilutions were prepared for shipment to Eurofins.

  18. Origin of high Zn contents in Jurassic limestone of the Jura mountain range and the Burgundy: evidence from Zn speciation

    E-Print Network [OSTI]

    Introduction Jurassic limestone of the Jura mountain range (JMR) and the Burgundy bear anomalously high zincOrigin of high Zn contents in Jurassic limestone of the Jura mountain range and the Burgundy in Jurassic limestone of the Jura mountain range (JMR) and the Burgundy (B), we investigated four loca- tions

  19. Hybrid density functional calculations of the defect properties of ZnO:Rh and ZnO:Ir

    E-Print Network [OSTI]

    Muñoz Ramo, David; Bristowe, Paul D.

    2014-03-31

    gap region and near the conduction band minimum, with a d-d splitting larger than 2 eV, which helps maintain transparency in the material. Addition of a hole to the simulation cell of both spinels and doped ZnO leads to charge localization...

  20. Fabrication and Physics of CdTe Devices by Sputtering: Final Report, 1 March 2005 - 30 November 2008

    SciTech Connect (OSTI)

    Compaan, A.; Collins, R.; Karpov, V.; Giolando, D.

    2009-04-01

    Work to understand CdS/CdTe solar cell device physics; increase magnetron sputtering rate (while keeping high device quality); reduce thickness of CdTe layers (while keeping voltage and fill factor).

  1. Theoretical study of syngas hydrogenation to methanol on the polar Zn-terminated ZnO(0001) surface

    SciTech Connect (OSTI)

    Zhao, Ya-Fan; Rousseau, Roger J.; Li, Jun; Mei, Donghai

    2012-08-02

    Methanol synthesis from syngas (CO/CO2/H2) hydrogenation on the perfect Zn–terminated polar ZnO(0001) surface have been investigated using periodic density functional theory calculations. Our results show that direct CO2 hydrogenation to methanol on the perfect ZnO(0001) surface is unlikely because in the presence of surface atomic H and O the highly stable formate (HCOO) and carbonate (CO3) readily produced from CO2 with low barriers 0.11 and 0.09 eV will eventually accumulate and block the active sites of the ZnO(0001) surface. In contrast, methanol synthesis from CO hydrogenation is thermodynamically and kinetically feasible on the perfect ZnO(0001) surface. CO can be consecutively hydrogenated into formyl (HCO), formaldehyde (H2CO), methoxy (H3CO) intermediates, leading to the final formation of methanol (H3COH). The reaction route via hydroxymethyl (H2COH) intermediate, a previously proposed species on the defected O–terminated ZnO( ) surface, is kinetically inhibited on the perfect ZnO(0001) surface. The rate-determining step in the consecutive CO hydrogenation route is the hydrogenation of H3CO to H3COH. We also note that this last hydrogenation step is pronouncedly facilitated in the presence of water by lowering the activation barrier from 1.02 to 0.55 eV. This work was supported by the U.S. Department of Energy Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences, and performed at EMSL, a national scientific user facility sponsored by the Department of Energy’s Office of Biological and Environmental Research located at Pacific Northwest National Laboratory (PNNL). Computational resources were provided at EMSL and the National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory. J. Li and Y.-F. Zhao were also financially supported by the National Natural Science Foundation of China (Nos. 20933003 and 91026003) and the National Basic Research Program of China (No. 2011CB932400). Y.-F. Zhao acknowledges the fellowship from PNNL.

  2. Pressure-induced Phase Transition in Thiol-capped CdTe Nanoparticles

    SciTech Connect (OSTI)

    Wu, F; Zaug, J; Young, C; Zhang, J Z

    2006-11-29

    Phase transitions for CdTe nanoparticles (NPs) under high pressure up to 37.0 GPa have been studied using fluorescence measurements. The phase transition from cinnarbar to rocksalt phase has been observed in CdTe NPs solution at 5.8 GPa, which is much higher than the phase transition pressure of bulk CdTe (3.8 GPa) and that of CdTe NPs in solid form (0.8 GPa). CdTe NPs solution therefore shows elevated phase transition pressure and enhanced stability against pressure compared with bulk CdTe and CdTe NPs in solid forms. The enhanced stability of CdTe NPs solution has been attributed to possible shape change in the phase transition and/or inhomogeneous strains in nanoparticle solutions.

  3. Cathepsin S regulates class II MHC processing in human CD4+ HLA-DR+ T cells

    E-Print Network [OSTI]

    Ploegh, Hidde

    Although it has long been known that human CD4+ T cells can express functional class II MHC molecules, the role of lysosomal proteases in the T cell class II MHC processing and presentation pathway is unknown. Using CD4+ ...

  4. Super-Poissonian Statistics of Photon Emission from Single CdSe...

    Office of Scientific and Technical Information (OSTI)

    Super-Poissonian Statistics of Photon Emission from Single CdSe-CdS Core-Shell Nanocrystals Coupled to Metal Nanostructures Citation Details In-Document Search Title:...

  5. THE ROLE OF ADAPTOR PROTEIN GADS IN CD8+ T CELL-MEDIATED IMMUNITY

    E-Print Network [OSTI]

    Zhang, Elizabeth Yan

    2011-12-31

    CD8+ T cells are the branch of the adaptive immune system responsible for recognizing and killing tumor cells or cells infected with intracellular pathogens, such as Listeria monocytogenes (LM). However, when CD8+ T cells target our own tissues...

  6. Nanoscale Imaging of Photocurrent 2 and Efficiency in CdTe Solar...

    Office of Scientific and Technical Information (OSTI)

    Nanoscale Imaging of Photocurrent 2 and Efficiency in CdTe Solar Cells. Citation Details In-Document Search Title: Nanoscale Imaging of Photocurrent 2 and Efficiency in CdTe Solar...

  7. CdTe Thin Film Solar Cells and Modules Tutorial; NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    Albin, David S.

    2015-06-13

    This is a tutorial presented at the 42nd IEEE Photovoltaics Specialists Conference to cover the introduction, background, and updates on CdTe cell and module technology, including CdTe cell and module structure and fabrication.

  8. Geochemical associations and availability of cadmium (Cd) in a paddy field system, Northwestern Thailand 

    E-Print Network [OSTI]

    Kosolsaksakul, Peerapat

    2014-11-27

    The Mae Tao watershed, northwestern Thailand, has become contaminated with cadmium (Cd) from the zinc mining activities area in the nearby Thanon-Thongchai mountains. Consumption of Cd-contaminated rice has led to ...

  9. Full multiple scattering analysis of XANES at the Cd L3 and O K edges in CdO films combined with a soft-x-ray emission investigation

    E-Print Network [OSTI]

    Demchenko, I. N.

    2012-01-01

    band ?VB? features for doped CdO material. Since this shiftceram- ics samples of CdO doped by Y and In were probed

  10. Enhanced ripening behavior of Mg-doped CdSe quantum dots

    E-Print Network [OSTI]

    Kim, Tae-Geun

    In this study, CdO and Mg acetate were added into a mixture of paraffin oil and oleic acid (45:5) by 5 and 1 mEnhanced ripening behavior of Mg-doped CdSe quantum dots Yun-Mo Sung,a) Woo-Chul Kwak, and Woong November 2007; accepted 24 March 2008) Pure CdSe and Mg-doped CdSe nanocrystal quantum dots were

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

    SciTech Connect (OSTI)

    Proffen, Thomas E; Kim, Yiung- Il; Cadars, Sylvian; Shayib, Ramzy; Feigerle, Charles S; Chmelka, Bradley F; Seshadri, Ram

    2008-01-01

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

  12. Energy relaxation in CdSe nanocrystals: the effects of morphology and film preparation

    E-Print Network [OSTI]

    Ruan, Xiulin

    solar cells. harvesting light energy with CdSe nanocrystals molecularly linked to mesoscopic TiO2 filmsEnergy relaxation in CdSe nanocrystals: the effects of morphology and film preparation Bryan T time-resolved absorption spectroscopy is used to investigate exciton dynamics in CdSe nanocrystal films

  13. USING CORIOLIS FORCE TO FACILITATE MOLECULAR TRANSPORTATION AND FLUID MIXING IN CD MICROFLUIDICS

    E-Print Network [OSTI]

    Kassegne, Samuel Kinde

    e. USING CORIOLIS FORCE TO FACILITATE MOLECULAR TRANSPORTATION AND FLUID MIXING IN CD MICROFLUIDICS Coriolis Force to Facilitate Molecular Transportation and Fluid Mixing in CD Microfluidics Platform and Fluid mixing in compact disk (CD) microfluidic platform where centrifugal force is used as the driving

  14. DISSERTATION ELECTRON-REFLECTOR STRATEGY FOR CdTe THIN-FILM SOLAR CELLS

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION ELECTRON-REFLECTOR STRATEGY FOR CdTe THIN-FILM SOLAR CELLS Submitted by Kuo-Jui Hsiao ELECTRON- REFLECTOR STRATEGY FOR CdTe THIN-FILM SOLAR CELLS BE ACCEPTED AS FULFILLING IN PART REQUIREMENTS-FILM SOLAR CELLS The CdTe thin-film solar cell has a large absorption coefficient and high theoretical

  15. Solar Energy Materials & Solar Cells 91 (2007) 13881391 Bifacial configurations for CdTe solar cells

    E-Print Network [OSTI]

    Romeo, Alessandro

    2007-01-01

    Solar Energy Materials & Solar Cells 91 (2007) 1388­1391 Bifacial configurations for CdTe solar We present a different back contact for CdTe solar cell by the application of only a transparent that acts as a free-Cu stable back contact and at the same time allows to realize bifacial CdTe solar cells

  16. Cross-Sectional Conductive Atomic Force Microscopy of CdTe/CdS Solar Cells: Effects of Etching and Back-Contact Processes; Preprint

    SciTech Connect (OSTI)

    Moutinho, H. R.; Dhere, R. G.; Jiang, C.-S.; Gessert, T. A.; Duda, A. M.; Young, M.; Metzger, W. K.; Li, X.; Al-Jassim, M. M.

    2006-05-01

    We investigated the effects of the etching processes using bromine and nitric-phosphoric acid solutions, as well as of Cu, in the bulk electrical conductivity of CdTe/CdS solar cells using conductive atomic force microscopy (C-AFM). Although the etching process can create a conductive layer on the surface of the CdTe, the layer is very shallow. In contrast, the addition of a thin layer of Cu to the surface creates a conductive layer inside the CdTe that is not uniform in depth, is concentrated at grains boundaries, and may short circuit the device if the CdTe is too thin. The etching process facilitates the Cu diffusion and results in thicker conductive layers. The existence of this inhomogeneous conductive layer directly affects the current transport and is probably the reason for needing thick CdTe in these devices.

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

    SciTech Connect (OSTI)

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

    2013-05-30

    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.

  18. Relationship between textural properties, fly ash carbons, and Hg capture in fly ashes derived from the combustion of anthracitic pulverized feed blends

    SciTech Connect (OSTI)

    Isabel Surez-Ruiz; Jose B. Parra

    2007-08-15

    In this work, the textural properties of a series of whole anthracitic-derived fly ashes sampled in eight hoppers from the electrostatic precipitators and their sized fractions (from {gt}150 to {lt}25 {mu}m) are investigated. Data from N{sub 2} adsorption isotherms at 77 K, helium density, and mercury porosimetry have contributed to establish a relationship between the Brunauer-Emmett-Teller (BET) surface areas, VTOT, porosity, carbon content (the type of fly ash carbons), and Hg retention in these fly ashes. The unburned carbons in these ashes are macroporous materials, and they are different from the carbons in fly ashes from classes C and F (the latter derived from the combustion of bituminous coals) and show different textural properties. These ashes represent the end member of the fly ash classes C and F with respect to certain textural properties. Although the BET surface area and VTOT values for the studied samples are the lowest reported, they increase with the increase in carbon content, anisotropic carbon content, and particle size of the ashes. Thus, a positive relationship between all these parameters and Hg capture by the coarser ash fractions was found. The finest fraction of carbons ({lt}25 {mu}m) represented an exception. Although it makes a significant contribution to the total carbon of the whole fly ashes and shows relatively higher surface areas and VTOT values, its Hg concentration was found to be the lowest. This suggests that the type of unburned carbons in the finest fraction and/or other adsorption mechanisms may play a role in Hg concentration. Because the textural properties of anisotropic carbons depend on their subtype and on their origin, the need for its differentiation has been evidenced. 54 refs., 8 figs., 3 tabs.

  19. ZnO:Sb/ZnO:Ga Light Emitting Diode on c-Plane Sapphire by Molecular Beam Epitaxy Zheng Yang, Sheng Chu, Winnie V. Chen1

    E-Print Network [OSTI]

    Yang, Zheng

    ZnO:Sb/ZnO:Ga Light Emitting Diode on c-Plane Sapphire by Molecular Beam Epitaxy Zheng Yang, Sheng substrates using plasma-assisted molecular-beam epitaxy. Mesa geometry light emitting diodes (LEDs) were demonstrated in recent years, such as photodetectors,8,9) light-emitting diodes (LEDs),10­13) and random lasing

  20. Atomic Layer Deposition of ZnO on Multi-walled Carbon Nanotubes and Its Use for Synthesis of CNT–ZnO Heterostructures

    E-Print Network [OSTI]

    2010-08-07

    Abstract In this article, direct coating of ZnO on PECVD-grown multi-walled carbon nanotubes (MWCNTs) is achieved using atomic layer deposition (ALD). Transmission electron microscopy investigation shows that the deposited ZnO shell is continuous...

  1. Stellar (n,{gamma}) cross sections of p-process isotopes. II. {sup 168}Yb, {sup 180}W, {sup 184}Os, {sup 190}Pt, and {sup 196}Hg

    SciTech Connect (OSTI)

    Marganiec, J.; Dillmann, I.; Pardo, C. Domingo; Kaeppeler, F.; Walter, S.

    2010-09-15

    The neutron-capture cross sections of {sup 168}Yb, {sup 180}W, {sup 184}Os, {sup 190}Pt, and {sup 196}Hg have been measured by means of the activation technique. The samples were irradiated in a quasistellar neutron spectrum of kT=25 keV, which was produced at the Karlsruhe 3.7-MV Van de Graaff accelerator via the {sup 7}Li(p,n){sup 7}Be reaction. Systematic uncertainties were investigated in repeated activations with different samples and by variation of the experimental parameters, that is, irradiation times, neutron fluxes, and {gamma}-ray counting conditions. The measured data were converted into Maxwellian-averaged cross sections at kT=30 keV, yielding 1214{+-}61, 624{+-}54, 590{+-}43, 511{+-}46, and 201{+-}11 mb for {sup 168}Yb, {sup 180}W, {sup 184}Os, {sup 190}Pt, and {sup 196}Hg, respectively. The present results either represent first experimental data ({sup 168}Yb, {sup 184}Os, and {sup 196}Hg) or could be determined with significantly reduced uncertainties ({sup 180}W and {sup 190}Pt). These measurements are part of a systematic study of stellar (n,{gamma}) cross sections of the stable p isotopes.

  2. Manufacturing Process Optimization to Improve Stability, Yield and Efficiency of CdS/CdTe PV Devices: Final Report, December 2004 - January 2009

    SciTech Connect (OSTI)

    Sampath, W. S.; Enzenroth, A.; Barth, K.

    2009-03-01

    The research by Colorado State University advances the understanding of device stability, efficiency, and process yield for CdTe PV devices.

  3. Hazardous waste site characterization (on cd-rom). Data file

    SciTech Connect (OSTI)

    1996-07-01

    Site characterization is one facet of hazardous waste site investigations. Environmental scientists and engineers within and outside the regulated community are becoming overwhelmed by the increasing number of guidance manuals, directives, documents and software products relating to the characterization of hazardous waste sites. People in the private sector, academia, and government are looking for convenient, definitive sources for this information. This CD-ROM combines into a single source a collection of useful references. The CD-ROM contains over 3,200 pages of EPA`s RCRA and Superfund Directives and Manuals that may be searched by key words or printed. It also contains a compilation of EPA-developed computer programs and documents to aid environmental professionals in the characterization of hazardous waste sites.

  4. High Spin Spectroscopy and Shape Evolution in 105Cd

    E-Print Network [OSTI]

    M. Kumar Raju; D. Negi; S. Muralithar; R. P. Singh; J. A. Sheikh; G. H. Bhat; R. Kumar; Indu Bala; T. Trivedi; A. Dhal; K. Rani; R. Gurjar; D. Singh; R. Palit; B. S. Naidu; S. Saha; J. Sethi; R. Donthi; S. Jadhav

    2015-01-30

    High spin states in 105Cd were studied using 16O beam on 92Mo reaction at an incident beam energy of 75 MeV. The level scheme of 105Cd has been observed up to an excitation energy of 10.8 MeV with the addition of 30 new gamma transitions to the previous work. Spin and parity for most of the reported levels are assigned from the DCO ratios and linear polarization measurements. The microscopic origin of the investigated band structures is discussed in the context of triaxial projected shell model. The energies of observed positive and negative parity bands agree with the predictions of the TPSM by considering triaxial deformation for the observed excited band structures. The shape evolution with increasing angular momentum is explained in the framework of Cranked Shell Model and the Total Routhian Surface calculations.

  5. Metal contacts on ZnSe and GaN

    SciTech Connect (OSTI)

    Duxstad, K J [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering

    1997-05-01

    Recently, considerable interest has been focused on the development of blue light emitting materials and devices. The focus has been on GaN and ZnSe, direct band gap semiconductors with bands gaps of 3.4 and 2.6 eV, respectively. To have efficient, reliable devices it is necessary to have thermally and electrically stable Ohmic contacts. This requires knowledge of the metal-semiconductor reaction behavior. To date few studies have investigated this behavior. Much information has accumulated over the years on the behavior of metals on Si and GaAs. This thesis provides new knowledge for the more ionic wide band gap semiconductors. The initial reaction temperatures, first phases formed, and phase stability of Pt, Pd, and Ni on both semiconductors were investigated. The reactions of these metals on ZnSe and GaN are discussed in detail and correlated with predicted behavior. In addition, comparisons are made between these highly ionic semiconductors and Si and GaAs. The trends observed here should also be applicable to other II-VI and III-Nitride semiconductor systems, while the information on phase formation and stability should be useful in the development of contacts for ZnSe and GaN devices.

  6. Impact of strain on electronic defects in (Mg,Zn)O thin films

    SciTech Connect (OSTI)

    Schmidt, Florian Müller, Stefan; Wenckstern, Holger von; Benndorf, Gabriele; Pickenhain, Rainer; Grundmann, Marius

    2014-09-14

    We have investigated the impact of strain on the incorporation and the properties of extended and point defects in (Mg,Zn)O thin films by means of photoluminescence, X-ray diffraction, deep-level transient spectroscopy (DLTS), and deep-level optical spectroscopy. The recombination line Y?, previously detected in ZnO thin films grown on an Al-doped ZnO buffer layer and attributed to tensile strain, was exclusively found in (Mg,Zn)O samples being under tensile strain and is absent in relaxed or compressively strained thin films. Furthermore a structural defect E3´ can be detected via DLTS measurements and is only incorporated in tensile strained samples. Finally it is shown that the omnipresent deep-level E3 in ZnO can only be optically recharged in relaxed ZnO samples.

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

    E-Print Network [OSTI]

    Yang, Zheng

    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

  8. Magnetism in undoped ZnS studied from density functional theory

    SciTech Connect (OSTI)

    Xiao, Wen-Zhi E-mail: llwang@hun.edu.cn; Rong, Qing-Yan; Xiao, Gang; Wang, Ling-ling E-mail: llwang@hun.edu.cn; Meng, Bo

    2014-06-07

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

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

    E-Print Network [OSTI]

    Cao, Guozhong

    NW and TiO2 nanotube arrays.6­9 However, the PCE of such DSC remained low, for example, ZnO NW DSC, typically TiO2 and ZnO network with dye molecules adsorbed onto the sur- face forming a monolayer. Dye into the conduction band of TiO2 or ZnO and transported to charge collector. In order to achieve high power conversion

  10. Hot-pressed ceramic Cr2+ :ZnSe gain-switched

    E-Print Network [OSTI]

    Mirov, Sergey B.

    Hot-pressed ceramic Cr2+ :ZnSe gain-switched laser A. Gallian, V. V. Fedorov, and S. B. Mirov: The technology of hot-pressed Cr2+ :ZnSe ceramic preparation is reported. Comparative gain-switched lasing of hot­pressed ceramic and CVD grown Cr2+ :ZnSe samples with slope efficiencies up to 10 % and output energies up to 2 m

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

    SciTech Connect (OSTI)

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

    2014-04-24

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

  12. Nonlinear optical characterization of ZnS thin film synthesized by chemical spray pyrolysis method

    SciTech Connect (OSTI)

    G, Sreeja V; Anila, E. I., E-mail: anilaei@gmail.com; R, Reshmi, E-mail: anilaei@gmail.com; John, Manu Punnan, E-mail: anilaei@gmail.com [Optolectronic and Nanomaterials Research Laboratory, Department of Physics, Union Christian College, Aluva-683 102, Kerala (India); V, Sabitha P; Radhakrishnan, P. [International School of Photonics, CUSAT, Cochin-22 (India)

    2014-10-15

    ZnS thin film was prepared by Chemical Spray Pyrolysis (CSP) method. The sample was characterized by X-ray diffraction method and Z scan technique. XRD pattern showed that ZnS thin film has hexagonal structure with an average size of about 5.6nm. The nonlinear optical properties of ZnS thin film was studied by open aperture Z-Scan technique using Q-switched Nd-Yag Laser at 532nm. The Z-scan plot showed that the investigated ZnS thin film has saturable absorption behavior. The nonlinear absorption coefficient and saturation intensity were also estimated.

  13. Metallic filament formation by aligned oxygen vacancies in ZnO-based resistive switches

    SciTech Connect (OSTI)

    Gu, Tingkun

    2014-05-28

    The electronic structure of ZnO with defects of oxygen vacancies were investigated by using first-principles methods. Some structure models were constructed in order to investigate the effects of the distribution of oxygen vacancies on the electronic properties of ZnO. By analyzing the calculated results, we found that only the aligned oxygen vacancies can form the conducting channel in ZnO, and the transformation of the oxygen vacancy from charged state to neutral state is consistent with the energetics rule of the forming aligned oxygen vacancies. As for the heterojunction of Pt/ZnO/Pt, the oxygen vacancies near the interface of Pt/ZnO depress the local Schottky barrier effectively, and the aligned oxygen vacancies in ZnO form a conducting filament connecting two Pt electrodes. The metallic filament formation in Pt/ZnO/Pt resistive switching cells should be closely related to the carrier injection from Pt electrode into ZnO and the arrangement of oxygen vacancies in ZnO slab.

  14. Green synthesis of graphene nanosheets/ZnO composites and electrochemical properties

    SciTech Connect (OSTI)

    Wang Jun; Gao Zan; Li Zhanshuang; Wang Bin; Yan Yanxia; Liu Qi; Mann, Tom; Zhang Milin; Jiang Zhaohua

    2011-06-15

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

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

    E-Print Network [OSTI]

    Lin, Wei

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

  16. Optimization of chemical bath deposited CdS thin films using nitrilotriacetic acid as a complexing agent

    E-Print Network [OSTI]

    Chow, Lee

    thin film solar cells based on CdTe or CIGS [1,2]. CdS has also been used in other applications. The highest efficiencies reported for both CdTe and CIGS solar cells were obtained when chemical bath is known to greatly enhance the performance of CdS windows used in the above mentioned solar cells

  17. Design and Investigation of Micro-Patterned Injection-Moulded Polymer Substrates for Use in CD-based Microfluidics

    E-Print Network [OSTI]

    Borissova, Daniela

    -based Microfluidics for Cell Manipulation ICOMM/4M 2010 No. 63 D. Trifonov1 , K. Kostadinov2 , M. Al-Wahab3 , V. Kotev MOULDING AND CD - BASED MICROFLUIDIC DEVICES Micro- and nanostructures can be replicated on polymer- devices like CD microfluidic platform for Bio-MEMS applications, Lab-on-a-CD, CD centrifugal mi

  18. Free bound and bound bound profiles in excitation spectra of the transition in CdNg (Ng = noble gas) complexes

    E-Print Network [OSTI]

    Free bound and bound bound profiles in excitation spectra of the B3 1 X1 0+ transition in CdNg (Ng, the characterization was improved. Morse functions for CdNg (Ng = noble gas) (also Lennard-Jones (12-6) for Cd groups to investigate CdNg (Ng = noble gas) complexes [1,2], and to spectroscopically characterize both

  19. Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells

    E-Print Network [OSTI]

    Cao, Guozhong

    Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells Ru Zhou-sensitized solar cell (QDSC) application. The photoanode films were composed of submicrometer-sized beads consisting of packed TiO2 nanocrystallites. A power conversion efficiency up to 4.05% has been achieved

  20. Synthesis and characterization of ZnO and Ni doped ZnO nanorods by thermal decomposition method for spintronics application

    SciTech Connect (OSTI)

    Saravanan, R.; Santhi, Kalavathy; Sivakumar, N.; Narayanan, V.; Stephen, A.

    2012-05-15

    Zinc oxide nanorods and diluted magnetic semiconducting Ni doped ZnO nanorods were prepared by thermal decomposition method. This method is simple and cost effective. The decomposition temperature of acetate and formation of oxide were determined by TGA before the actual synthesis process. The X-ray diffraction result indicates the single phase hexagonal structure of zinc oxide. The transmission electron microscopy and scanning electron microscopy images show rod like structure of ZnO and Ni doped ZnO samples with the diameter {approx} 35 nm and the length in few micrometers. The surface analysis was performed using X-ray photoelectron spectroscopic studies. The Ni doped ZnO exhibits room temperature ferromagnetism. This diluted magnetic semiconducting Ni doped ZnO nanorods finds its application in spintronics. - Highlights: Black-Right-Pointing-Pointer The method used is very simple and cost effective compared to all other methods for the preparation DMS materials. Black-Right-Pointing-Pointer ZnO and Ni doped ZnO nanorods Black-Right-Pointing-Pointer Ferromagnetism at room temperature.

  1. Multi-Pollutant Emissions Control: Pilot Plant Study of Technologies for Reducing Hg, SO3, NOx and CO2 Emissions

    SciTech Connect (OSTI)

    Michael L. Fenger; Richard A. Winschel

    2005-08-31

    A slipstream pilot plant was built and operated to investigate technology to adsorb mercury (Hg) onto the existing particulate (i.e., fly ash) by cooling flue gas to 200-240 F with a Ljungstrom-type air heater or with water spray. The mercury on the fly ash was then captured in an electrostatic precipitator (ESP). An alkaline material, magnesium hydroxide (Mg(OH){sub 2}), is injected into flue gas upstream of the air heater to control sulfur trioxide (SO{sub 3}), which prevents acid condensation and corrosion of the air heater and ductwork. The slipstream was taken from a bituminous coal-fired power plant. During this contract, Plant Design and Construction (Task 1), Start Up and Maintenance (Task 2), Baseline Testing (Task 3), Sorbent Testing (Task 4), Parametric Testing (Task 5), Humidification Tests (Task 6), Long-Term Testing (Task 7), and a Corrosion Study (Task 8) were completed. The Mercury Stability Study (Task 9), ESP Report (Task 11), Air Heater Report (Task 12) and Final Report (Task 14) were completed. These aspects of the project, as well as progress on Public Outreach (Task 15), are discussed in detail in this final report. Over 90% mercury removal was demonstrated by cooling the flue gas to 200-210 F at the ESP inlet; baseline conditions with 290 F flue gas gave about 26% removal. Mercury removal is sensitive to flue gas temperature and carbon content of fly ash. At 200-210 F, both elemental and oxidized mercury were effectively captured at the ESP. Mg(OH){sub 2} injection proved effective for removal of SO{sub 3} and eliminated rapid fouling of the air heater. The pilot ESP performed satisfactorily at low temperature conditions. Mercury volatility and leaching tests did not show any stability problems. No significant corrosion was detected at the air heater or on corrosion coupons at the ESP. The results justify larger-scale testing/demonstration of the technology. These conclusions are presented and discussed in two presentations given in July and September of 2005 and are included in Appendices E and F.

  2. Structural Stability and Defect Energetics of ZnO from Diffusion Quantum Monte Carlo

    SciTech Connect (OSTI)

    Santana Palacio, Juan A [ORNL; Krogel, Jaron T [ORNL; Kim, Jeongnim [ORNL; Kent, Paul R [ORNL; Reboredo, Fernando A [ORNL

    2015-01-01

    We have applied the many-body ab-initio diffusion quantum Monte Carlo (DMC) method to study Zn and ZnO crystals under pressure, and the energetics of the oxygen vacancy, zinc interstitial and hydrogen impurities in ZnO. We show that DMC is an accurate and practical method that can be used to characterize multiple properties of materials that are challenging for density functional theory approximations. DMC agrees with experimental measurements to within 0.3 eV, including the band-gap of ZnO, the ionization potential of O and Zn, and the atomization energy of O2, ZnO dimer, and wurtzite ZnO. DMC predicts the oxygen vacancy as a deep donor with a formation energy of 5.0(2) eV under O-rich conditions and thermodynamic transition levels located between 1.8 and 2.5 eV from the valence band maximum. Our DMC results indicate that the concentration of zinc interstitial and hydrogen impurities in ZnO should be low under n-type, and Zn- and H-rich conditions because these defects have formation energies above 1.4 eV under these conditions. Comparison of DMC and hybrid functionals shows that these DFT approximations can be parameterized to yield a general correct qualitative description of ZnO. However, the formation energy of defects in ZnO evaluated with DMC and hybrid functionals can differ by more than 0.5 eV.

  3. DOE CD-4 Review of the MINERvA Project

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of raregovAboutRecoveryplanningCoalSocialFrameworksNOWRegisterDOE CD-1/2/3a3b4

  4. Wind Energy Resource Atlas of Armenia (CD-ROM)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking WithTelecentricNCubicthe FOIA?Resource Atlas of Armenia (CD-ROM)

  5. Method of controlling the mercury vapor pressure in a photo-chemical lamp or vapor filter used for Hg[sup 196] enrichment

    DOE Patents [OSTI]

    Grossman, M.W.

    1993-02-16

    The present invention is directed to a method of eliminating the cold spot zones presently used on Hg[sup 196] isotope separation lamps and filters by the use of a mercury amalgams, preferably mercury - indium amalgams. The use of an amalgam affords optimization of the mercury density in the lamp and filter of a mercury enrichment reactor, particularly multilamp enrichment reactors. Moreover, the use of an amalgam in such lamps and/or filters affords the ability to control the spectral line width of radiation emitted from lamps, a requirement for mercury enrichment.

  6. Method of controlling the mercury vapor pressure in a photo-chemical lamp or vapor filter used for Hg.sup.196 enrichment

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA)

    1993-01-01

    The present invention is directed to a method of eliminating the cold spot zones presently used on Hg.sup.196 isotope separation lamps and filters by the use of a mercury amalgams, preferably mercury - indium amalgams. The use of an amalgam affords optimization of the mercury density in the lamp and filter of a mercury enrichment reactor, particularly multilamp enrichment reactors. Moreover, the use of an amalgam in such lamps and/or filters affords the ability to control the spectral line width of radiation emitted from lamps, a requirement for mercury enrichment.

  7. Band-gap tailoring of ZnO by means of heavy Al doping

    SciTech Connect (OSTI)

    Sernelius, B.E.; Berggren, K.; Jin, Z.; Hamberg, I.; Granqvist, C.G.

    1988-06-15

    Films of ZnO:Al were produced by weakly reactive dual-target magnetron sputtering. Optical band gaps, evaluated from spectrophotometric data, were widened in proportion to the Al doping. The widening could be quantitatively reconciled with an effective-mass model for n-doped semiconductors, provided the polar character of ZnO was accounted for.

  8. Magnetic and structural properties of Zn doped MnV{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Shahi, Prashant; Shukla, K. K.; Singh, Rahul; Chatterjee, Sandip; Das, A.; Ghosh, A. K.; Nigam, A. K.

    2014-04-24

    The magnetization, Neutron diffraction and X-ray diffraction of Zn doped MnV{sub 2}O{sub 4} as a function of temperature have been measured. It has been observed, with increase of Zn the non-linear orientation of Mn spins with the V spins will decrease which effectively decrease the structural transition temperature more rapidly than Curie Temperature.

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

    E-Print Network [OSTI]

    Zheng, Yufeng

    Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China c metallic glass with different compositions (Mg66Zn30Ca4 and Mg70Zn25Ca5) have been prepared for this study and their feasibility as biodegradable metallic materials have been eval- uated by the microstructural, surface analysis

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

    E-Print Network [OSTI]

    Goddard III, William A.

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

  11. Manganese-doped ZnO nanobelts for spintronics C. Ronning,a)

    E-Print Network [OSTI]

    Wang, Zhong L.

    Manganese-doped ZnO nanobelts for spintronics C. Ronning,a) P. X. Gao, Y. Ding, and Z. L. Wangb and luminescence. The produced high-quality ZnO:Mn nanobelts are potentially useful for spintronics. © 2004 of the promising materials for spintronics (spin electronics), a proposed technology that uses the electron spin

  12. ZnO Spintronics and Nanowire Devices S.J. PEARTON,1,4

    E-Print Network [OSTI]

    Hebard, Arthur F.

    ZnO Spintronics and Nanowire Devices S.J. PEARTON,1,4 D.P. NORTON,1 Y.W. HEO,1 L.C. TIEN,1 M, University of Florida. 4.--E-mail: spear@mse. ufl.edu ZnO is a very promising material for spintronics

  13. Hierarchical Ag/ZnO micro/nanostructure: Green synthesis and enhanced photocatalytic performance

    SciTech Connect (OSTI)

    Gao, Shuyan; Jia, Xiaoxia; Yang, Shuxia; Li, Zhengdao; Jiang, Kai

    2011-04-15

    Ag/ZnO metal-semiconductor nanocomposites with hierarchical micro/nanostructure have been prepared by the hydrothermal synthesis in the presence of bovine serum albumin (BSA). The results suggest that this biomolecule-assisted hydrothermal method is an efficient route for the fabrication of Ag/ZnO nanocomposites by using BSA both a shape controller and a reducing agent of Ag{sup +} ions. Moreover, Ag nanoparticles on the ZnO act as electron sinks, improving the separation of photogenerated electrons and holes, increasing the surface hydroxyl contents of ZnO, facilitating trapping the photoinduced electrons and holes to form more active hydroxyl radicals, and thus, enhancing the photocatalytic efficiency of ZnO. This is a good example for the organic combination of green chemistry and functional materials. -- Graphical Abstract: A green strategy is report to construct Ag/ZnO metal-semiconductor nanocomposites with hierarchical micro/nanostructure and enhanced photocatalytic activity. Display Omitted Research highlights: > Hierarchical micro/nanostructured Ag/ZnO nanocomposites have been prepared via a green route. > Ag nanoparticles improve the separation of photogenerated electrons and holes. > This facilitates trapping the photoinduced electrons and holes to form more hydroxyl radicals. Therefore, it enhances the photocatalytic efficiency of ZnO.

  14. Optical and Excitonic Properties of Crystalline ZnS Nanowires: Toward Efficient Ultraviolet

    E-Print Network [OSTI]

    Xiong, Qihua

    semiconductor, has been most widely used for phosphor host,5 optical coating, and solar cells.6 Due to the wide luminescence. Despite their advantageous band gap, bulk or thin film ZnS materials have not been able, such as ZnS epilayers fabricated on GaAs by MBE8 and NWs grown by PLV15 or MBE.20 Although those reports

  15. Optical and electronic properties of highly stable and textured hydrogenated ZnO:Al thin films

    SciTech Connect (OSTI)

    Hwang, Younghun, E-mail: younghh@ulsan.ac.kr [Basic Science Research Institute, University of Ulsan, Ulsan 680-749 (Korea, Republic of)] [Basic Science Research Institute, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Kim, Hyungmin [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of)] [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Um, Youngho, E-mail: yhum@ulsan.ac.kr [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of)] [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Park, Hyoyeol [Semiconductor Applications, Ulsan College, Ulsan 680-749 (Korea, Republic of)] [Semiconductor Applications, Ulsan College, Ulsan 680-749 (Korea, Republic of)

    2012-09-15

    Highlights: ? We investigate the impact of hydrogen treatment at high temperature of ZnO:Al film. ? Electrical properties of the ZnO:Al films improved due to hydrogen annealing. ? Optical properties of the ZnO:Al films enhanced due to hydrogen annealing. ? ZnO:Al film properties strongly depend on the hydrogen treatment temperature. -- Abstract: We have experimentally investigated the effects of hydrogen-annealing on the structural, electrical, and optical properties of Al-doped ZnO (ZnO:Al) thin films prepared by RF magnetron sputtering at room temperature. From the X-ray diffraction observations, the orientation of ZnO:Al films was found to be a c-axis in the hexagonal structure. We found that intentionally incorporated hydrogen plays an important role in n-type conduction as a donor, improving free carrier concentration and electrical stability. We simultaneously obtained improved optical transmission and enhanced absorption edge of the ZnO:Al film due to hydrogen-annealing. Our experimental data suggest the hydrogen-annealing process as an important role in the enhancement of electrical and optical properties, which is promising as a back reflector material for thin-film solar cells.

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

    E-Print Network [OSTI]

    Verbree, Cheryl

    2012-10-19

    breeders in Mali are working to increase sorghum grain Fe and Zn concentrations. The objective of this study was to investigate soil and mold influences that affect Fe and Zn uptake and accumulation in sorghum grain. In southern Mali, soils from...

  17. Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2

    E-Print Network [OSTI]

    Kimball, Gregory

    .6 However, even the basic materials parameters of Zn3P2, such as the energy gap, remainPhotoluminescence-based measurements of the energy gap and diffusion length of Zn3P2 Gregory M and Beckman Institute, California Institute of Technology, Pasadena, California 91125, USA Received 29 June

  18. Formation of single crystalline ZnO nanotubes without catalysts and templates

    E-Print Network [OSTI]

    Geohegan, David B.

    nanotubes. GaN,1 silica,2 ZnO,3,4 and TiO2 Ref. 5 nanotubes have been synthesized by using multistep#12;Formation of single crystalline ZnO nanotubes without catalysts and templates Samuel L. Mensah January 2007; published online 13 March 2007 Oxide and nitride nanotubes have gained attention

  19. ZnO/LSMO Nanocomposites for Energy Harvesting Robert Kinner1$

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    , and underutilized from other sources. Since green vegetation and plants utilize carbon dioxide to store sun's energy ZnO/LSMO Nanocomposites for Energy Harvesting Robert Kinner1$ , Abdul-Majeed Azad1 , G (LSMO) with zinc oxide (ZnO) are candidate materials for energy harvesting by virtue of their magnetic

  20. Precipitation microstructure of ultrafine-grained Al-Zn-Mg alloys processed by severe plastic deformation

    E-Print Network [OSTI]

    Gubicza, Jenõ

    Precipitation microstructure of ultrafine-grained Al-Zn-Mg alloys processed by severe plastic analysis, supersaturated AlZnMg alloys, dislocation density, precipitation. Abstract. Supersaturated Al-4 of the dislocation structure of both Al matrix and precipitates were determined by X-ray diffraction line profile

  1. Phosphorus Doped Zn1-xMgxO Nanowire J. I. Hong,

    E-Print Network [OSTI]

    Wang, Zhong L.

    output measurements, X-ray photoelectron spectroscopy, and the transport property between the NWs and a n in high-efficiency all-ZnO NWs based LED, high-output ZnO nanogenerator, and other optical or electrical,2 biosciences,3 and energy sciences.4 Nanowire light emitting diodes (LEDs), for example, have

  2. Dielectric properties of Bi2(Zn1/3Nb2/3)2O7 electroceramics and thin lms

    E-Print Network [OSTI]

    Ku?el, Petr

    Dielectric properties of Bi2(Zn1/3Nb2/3)2O7 electroceramics and thin ®lms Hsiu-Fung Cheng a, *, Yi 2000 Abstract Dielectric response of Bi2(Zn1/3Nb2/3)2O7, BiZN, ceramic materials and thin ®lms were at optimized sintering temperature (1050 C, 4 h). Crystalline BiZN thin ®lms, can be easily obtained when

  3. PUBLISHED ONLINE: 27 SEPTEMBER 2009 | DOI: 10.1038/NMAT2542 MgZnCa glasses without clinically observable

    E-Print Network [OSTI]

    Giger, Christine

    by a model based on the calculated Pourbaix diagram of Zn in simulated body fluid. We document animal studies

  4. Temperature dependence of the elastic constants of solid and liquid Cd0.96Zn0.04Te obtained by laser ultrasound

    E-Print Network [OSTI]

    Wadley, Haydn

    infrared focal plane array IRFPA sensors.1­3 As the size of imaging detectors continues to increase, a need a complete evaluation of the temperature dependent single crystal elastic stiffness constants C11 , C12 , C44 for the solid and the adiabatic bulk modulus (KS) for the liquid. In addition, evaluation of the thermoelastic

  5. The Antimony-Based Type I Clathrate compounds Cs8Cd18Sb28 and Cs8Zn18Sb28**

    SciTech Connect (OSTI)

    Liu, Yi; Wu, Li-Ming; Li, Long-Hua; Du, Shao-Wu; Corbett, John D.; Chen, Ling

    2009-06-17

    The title compounds lie in a new region of phase space for such a structure, and have stoichiometries in accord with a classical Zintl phase formulation. The small semiconductor gaps indicated by DFT calculations are also supported by their diamagnetic susceptibilities.

  6. Photoluminescence spectral study of single CdSe/ZnS Colloidal Nanocrystals in Poly(methyl methacrylate) and Quantum Dots molecules

    E-Print Network [OSTI]

    Shen, Yaoming

    2008-01-01

    E a and E b are thermal activation energies. ActivationE a ex- hibits the thermal activation energy of carriersthermal quenching, the curves tend to form a straight line at high temperature. Activation

  7. PHYSICAL REVIEW B 91, 245202 (2015) Improved predictions of the physical properties of Zn-and Cd-based wide band-gap

    E-Print Network [OSTI]

    Curtarolo, Stefano

    2015-01-01

    Department of Physics, Central Michigan University, Mt. Pleasant, Michigan 48859, USA 2 Center for Materials scrutiny for their potential applications in spintronics, optoelectronics, and photovoltaics [1

  8. Photoluminescence spectral study of single CdSe/ZnS Colloidal Nanocrystals in Poly(methyl methacrylate) and Quantum Dots molecules

    E-Print Network [OSTI]

    Shen, Yaoming

    2008-01-01

    in self- assembled inp quantum dots in gainp. Phys. Rev. B,in self-assembled inp quantum dots. Phys. Rev. Lett. , 86(also been observed in InP quantum dots in a Ga x In 1?x P

  9. Polymer-ZnO nanocomposites foils and thin films for UV protection

    SciTech Connect (OSTI)

    Shanshool, Haider Mohammed; Yahaya, Muhammad; Abdullah, Ibtisam Yahya [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, University Putra Malaysia, 43400 UPM, Serdang (Malaysia)

    2014-09-03

    The damage of UV radiation on human eye and skin is extensively studied. In the present work, the nanocomposites foils and thin films have been prepared by using casting method and spin coating, respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with Polymethyl methacrylate (PMMA) and Polyvinylidene fluoride (PVDF) as polymer matrix. Different contents of ZnO nanoparticles were used as filler in the nanocomposites. UV-Vis spectra showed very low transmittance in UV region that decreases with increase content of ZnO. PVDF/ZnO samples showed the lowest transmittance. The rough surface of PVDF was observed from SEM image. While a homogeneous dispersion of ZnO nanoparticles in PMMA were indicated by FESEM images.

  10. Emission Properties from ZnO Quantum Dots Dispersed in SiO{sub 2} Matrix

    SciTech Connect (OSTI)

    Panigrahi, Shrabani; Basak, Durga

    2011-07-15

    Dispersion of ZnO quantum dots in SiO{sub 2} matrix has been achieved in two techniques based on StOeber method to form ZnO QDs-SiO{sub 2} nanocomposites. Sample A is formed with random dispersion by adding tetraethyl orthosilicate (TEOS) to an ethanolic solution of ZnO nanoparticles and sample B is formed with a chain-like ordered dispersion by adding ZnO nanoparticles to an already hydrolyzed ethanolic TEOS solution. The photoluminescence spectra of the as-grown nanocomposites show strong emission in the ultraviolet region. When annealed at higher temperature, depending on the sample type, these show strong red or white emission. Interestingly, when the excitation is removed, the orderly dispersed ZnO QDs-SiO{sub 2} composite shows a very bright blue fluorescence visible by naked eyes for few seconds indicating their promise for display applications.

  11. Atomic layer deposition of zinc sulfide with Zn(TMHD){sub 2}

    SciTech Connect (OSTI)

    Short, Andrew; Jewell, Leila; Doshay, Sage; Church, Carena; Keiber, Trevor; Bridges, Frank; Carter, Sue; Alers, Glenn

    2013-01-15

    The atomic layer deposition (ALD) of ZnS films with Zn(TMHD){sub 2} and in situ generated H{sub 2}S as precursors was investigated, over a temperature range of 150-375 Degree-Sign C. ALD behavior was confirmed by investigation of growth behavior and saturation curves. The properties of the films were studied with atomic force microscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy, ultraviolet-visible-infrared spectroscopy, and extended x-ray absorption fine structure. The results demonstrate a film that can penetrate a porous matrix, with a local Zn structure of bulk ZnS, and a band gap between 3.5 and 3.6 eV. The ZnS film was used as a buffer layer in nanostructured PbS quantum dot solar cell devices.

  12. Controlled etching of hexagonal ZnO architectures in an alcohol thermal process

    SciTech Connect (OSTI)

    Wu, Junshu [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)] [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China); Xue, Dongfeng, E-mail: dfxue@chem.dlut.edu.cn [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)] [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)

    2010-03-15

    An alcohol thermal technique was applied to the controlled growth of hexagonal ZnO architectures via selective chemical etching. ZnO microdisks were produced first under mild alcohol thermal conditions in presence of formamide. Due to a higher surface energy/atomic density of Zn{sup 2+} {l_brace}0 0 0 1{r_brace} than that of the other faces, hexagonal ZnO microring was obtained by selectively etching positive polar surface of disk-like precursor with a high density of planar defects at the center. The selective etching of ZnO is related to its crystallographic characteristics of surface polarity and chemical activities, which opens a new opportunity for the shape-controlled synthesis of wurtzite-structured materials.

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

    SciTech Connect (OSTI)

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

    2006-10-02

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

  14. Defect-free ZnO nanorods for low temperature hydrogen sensor applications

    SciTech Connect (OSTI)

    Ranwa, Sapana; Kumar, Mahesh; Kulriya, Pawan K.; Sahu, Vikas Kumar; Kukreja, L. M.

    2014-11-24

    Uniformly distributed and defect-free vertically aligned ZnO nanorods (NRs) with high aspect ratio are deposited on Si by sputtering technique. X-ray diffraction along with transmission electron microscopy studies confirmed the single crystalline wurtzite structure of ZnO. Absence of wide band emission in photoluminescence spectra showed defect-free growth of ZnO NRs which was further conformed by diamagnetic behavior of the NRs. H{sub 2} sensing mechanism based on the change in physical dimension of channel is proposed to explain the fast response (?21.6?s) and recovery times (?27?s) of ZnO NRs/Si/ZnO NRs sensors. Proposed H{sub 2} sensor operates at low temperature (?70?°C) unlike the existing high temperature (>150?°C) sensors.

  15. Speciation of Zn in Blast Furnace Sludge from Former Sedimentation Ponds Using Synchrotron Xray Diffraction, Fluorescence, and

    E-Print Network [OSTI]

    in the octahedral sheets of phyllosilicates, (2) Zn sulfide minerals (ZnS, sphalerite, or wurtzite), (3) Zn in a KZn-ferrocyanide of the BFS. Similarly, the abundance of the KZn-ferrocyanide phase was closely correlated with the total CN

  16. Iron-based soft magnetic composites with MnZn ferrite nanoparticles coating obtained by solgel method

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Iron-based soft magnetic composites with Mn­Zn ferrite nanoparticles coating obtained by sol nanoparticles to coat iron powder. The nanocrystalline iron powders, with an average particle diameter of 20 nm­Zn ferrites. Mn­Zn ferrite uniformly coated the surface of the powder particles, resulting in a reduced

  17. Mechanical and electronic-structure properties of compressed CdSe tetrapod nanocrystals

    E-Print Network [OSTI]

    Schrier, Joshua; Lee, Byounghak; Wang, Lin-Wang

    2008-01-01

    Mechanical and electronic-structure properties of compressed94720 USA The coupling of mechanical and optical propertiestheoretical examination of the mechanical properties of CdSe

  18. A CD45 Polymorphism Associated with Multiple Sclerosis Disrupts an Exonic Splicing Silencer*

    E-Print Network [OSTI]

    Sharp, Kim

    A CD45 Polymorphism Associated with Multiple Sclerosis Disrupts an Exonic Splicing Silencer multiple sclerosis. In this study we investigated the mechanism by which the polymor- phism enhances

  19. Semiconductor quantum dots enhanced graphene/CdTe heterostructure solar cells by photo-induced doping

    E-Print Network [OSTI]

    Li, Xiaoqiang; Wang, Peng; Xu, Zhijuan; Zhong, Huikai; Wu, Zhiqian; Lin, Shisheng

    2015-01-01

    Photo-induced doping is employed into graphene based solar cell through designing of a novel type of solar cell based on graphene/CdTe Schottky heterostructure. By coating a layer of ultrathin CdSe quantum dots onto graphene/CdTe heterostructure, the performance of the graphene/CdTe solar cell is improved by about 50%. Photo-induced doping is mainly accounted for this enhancement, as evidenced by resistance, photoluminescence and quantum efficiency measurements. This work demonstrates a general and feasible way of designing novel type of solar cells based on two dimensional materials/semiconductor heterostructures.

  20. Characterization and Analysis of CIGS and CdTE Solar Cells: December 2004 - July 2008

    SciTech Connect (OSTI)

    Sites, J. R.

    2009-01-01

    The work reported here embodies a device-physics approach based on careful measurement and interpretation of data from CIGS and CdTe solar cells.

  1. White luminescence from CdS nanocrystals under the blue light excitation

    SciTech Connect (OSTI)

    Li, Bo; Zhang, Xiaosong Li, Lan; Li, Mengzhen; Xu, Jianping; Hong, Yuan

    2014-06-01

    Trap-rich CdS nanocrystals were synthesized by employing CdSt{sub 2} and sulfur as precursors via thermal decomposition. Furthermore, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), absorption and photoluminescence (PL) spectra were used to characterize structure, morphology and luminescence properties of CdS nanocrystals (NCs). CdS NCs have a broad emission across 500–700 nm under the excitation of blue light with 460 nm, consequently, white light can be produced by mixing broad emission from CdS NCs excited by blue light, with the remaining blue light. In addition, the broad emission generation is closely and inseparably related to surface defects. Moreover, LaMer model was used to explain the phenomenon that the intensity of the trap emission gradually decreases as the reaction time increases in contrast with that of the band-edge emission. - Graphical abstract: Trap-rich CdS nanocrystals were synthesized. Furthermore, white light is produced by mixing broad emission across 500–700 nm from CdS NCs excited by blue light, in combination with the remaining blue light. - Highlights: • Trap-rich CdS nanocrystals were synthesized. • CdS NCs have a broad emission across 500–700 nm under the excitation of blue light. • White light can be produced by mixing broad emission with the remaining blue light.

  2. Advanced CdTe Photovoltaic Technology: September 2007 - March 2009

    SciTech Connect (OSTI)

    Barth, K.

    2011-05-01

    During the last eighteen months, Abound Solar (formerly AVA Solar) has enjoyed significant success under the SAI program. During this time, a fully automated manufacturing line has been developed, fabricated and commissioned in Longmont, Colorado. The facility is fully integrated, converting glass and semiconductor materials into complete modules beneath its roof. At capacity, a glass panel will enter the factory every 10 seconds and emerge as a completed module two hours later. This facility is currently undergoing trials in preparation for large volume production of 120 x 60 cm thin film CdTe modules. Preceding the development of the large volume manufacturing capability, Abound Solar demonstrated long duration processing with excellent materials utilization for the manufacture of high efficiency 42 cm square modules. Abound Solar prototype modules have been measured with over 9% aperture area efficiency by NREL. Abound Solar demonstrated the ability to produce modules at industry leading low costs to NREL representatives. Costing models show manufacturing costs below $1/Watt and capital equipment costs below $1.50 per watt of annual manufacturing capacity. Under this SAI program, Abound Solar supported a significant research and development program at Colorado State University. The CSU team continues to make progress on device and materials analysis. Modeling for increased device performance and the effects of processing conditions on properties of CdTe PV were investigated.

  3. High-throughput manufacturing of thin-film CdS/CdTe photovoltaic modules. Annual subcontract report, 16 September 1996--15 January 1998

    SciTech Connect (OSTI)

    Sandwisch, D.W. [Solar Cells, Inc., Toledo, OH (United States)

    1998-08-01

    Cadmium telluride (CdTe) is recognized as one of the leading materials for low-cost photovoltaic modules. Solar Cells, Inc., has developed this technology and is scaling its pilot production capabilities to a multi-megawatt level. The Photovoltaic Manufacturing Technology (PVMaT) subcontract supports these efforts. Activities during the third phase of the program concentrated on process development, equipment design and testing, quality assurance, ES and H programs, and large-scale next-generation coating-system prototype development. These efforts broadly addressed the issues of the manufacturing process for producing thin-film, monolithic CdS/CdTe photovoltaic modules.

  4. CYP2E1-dependent and leptin-mediated hepatic CD57 expression on CD8 + T cells aid progression of environment-linked nonalcoholic steatohepatitis

    SciTech Connect (OSTI)

    Seth, Ratanesh Kumar; Das, Suvarthi; Kumar, Ashutosh; Chanda, Anindya; Kadiiska, Maria B.; Michelotti, Gregory; Manautou, Jose; Diehl, Anna Mae; Chatterjee, Saurabh

    2014-01-01

    Environmental toxins induce a novel CYP2E1/leptin signaling axis in liver. This in turn activates a poorly characterized innate immune response that contributes to nonalcoholic steatohepatitis (NASH) progression. To identify the relevant subsets of T-lymphocytes in CYP2E1-dependent, environment-linked NASH, we utilized a model of diet induced obese (DIO) mice that are chronically exposed to bromodichloromethane. Mice deficient in CYP2E1, leptin (ob/ob mice), or both T and B cells (Pfp/Rag2 double knockout (KO) mice) were used to delineate the role of each of these factors in metabolic oxidative stress-induced T cell activation. Results revealed that elevated levels of lipid peroxidation, tyrosyl radical formation, mitochondrial tyrosine nitration and hepatic leptin as a consequence of metabolic oxidative stress caused increased levels of hepatic CD57, a marker of peripheral blood lymphocytes including NKT cells. CD8 + CD57 + cytotoxic T cells but not CD4 + CD57 + cells were significantly decreased in mice lacking CYP2E1 and leptin. There was a significant increase in the levels of T cell cytokines IL-2, IL-1?, and IFN-? in bromodichloromethane exposed DIO mice but not in mice that lacked CYP2E1, leptin or T and B cells. Apoptosis as evidenced by TUNEL assay and levels of cleaved caspase-3 was significantly lower in leptin and Pfp/Rag2 KO mice and highly correlated with protection from NASH. The results described above suggest that higher levels of oxidative stress-induced leptin mediated CD8 + CD57 + T cells play an important role in the development of NASH. It also provides a novel insight of immune dysregulation and may be a key biomarker in NASH. - Highlights: • Metabolic oxidative stress caused increased levels of hepatic CD57 expression. • CD8+ CD57+ cytotoxic T cells were decreased in mice lacking CYP2E1 and leptin. • There was a significant increase in T cell cytokines in toxin-treated mice. • Apoptosis was significantly lower in leptin and Pfp/Rag2 KO mice. • Leptin mediated CD8+CD57+ T cells play an important role in NASH.

  5. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

    SciTech Connect (OSTI)

    Nick Degenstein; Minish Shah; Doughlas Louie

    2012-05-01

    The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

  6. Plasmonic excitations in ZnO/Ag/ZnO multilayer systems: Insight into interface and bulk electronic properties

    SciTech Connect (OSTI)

    Philipp, Martin; Knupfer, Martin; Buechner, Bernd; Gerardin, Hadia

    2011-03-15

    Electron energy-loss spectroscopy experiments in transmission were carried out on silver-based multi-layer systems, consisting of a silver layer of various thicknesses (8, 10 and 50 nm) sandwiched between two Al-doped ZnO layers. The films were produced by magnetron sputtering using potassium bromide single crystals as substrates. The electronic structure of these systems was probed and analyzed with respect to their plasmonic excitations, which can be basically split up into excitations of the electrons in the bulk silver and excitations at the ZnO:Al/Ag interface. A detailed examination of the momentum dependence of the plasmon peaks revealed a positive dispersion for both, the volume and the interface plasmon, where only for the first one a quadratic behavior (as expected for a free electron gas) could be observed. Furthermore, the peak width was analyzed and set into relation to electrical conductivity measurements by calculating the plasmon lifetime and the electron scattering rate. Here, a good agreement between these different methods was obtained.

  7. First principles investigations on the electronic structure of anchor groups on ZnO nanowires and surfaces

    SciTech Connect (OSTI)

    Dominguez, A.; Lorke, M.; Rosa, A. L.; Frauenheim, Th. [BCCMS, Universität Bremen, Am Fallturm 1, 28359 Bremen (Germany); Schoenhalz, A. L.; Dalpian, G. M. [CCNH, Universidade Federal do ABC, Av. dos Estados 5001, Santo André (Brazil); Rocha, A. R. [IFT, Universidade Estadual Paulista, R. Dr. Bento Teobaldo Ferraz, 271, São Paulo (Brazil)

    2014-05-28

    We report on density functional theory investigations of the electronic properties of monofunctional ligands adsorbed on ZnO-(1010) surfaces and ZnO nanowires using semi-local and hybrid exchange-correlation functionals. We consider three anchor groups, namely thiol, amino, and carboxyl groups. Our results indicate that neither the carboxyl nor the amino group modify the transport and conductivity properties of ZnO. In contrast, the modification of the ZnO surface and nanostructure with thiol leads to insertion of molecular states in the band gap, thus suggesting that functionalization with this moiety may customize the optical properties of ZnO nanomaterials.

  8. Low temperature atomic layer deposited ZnO photo thin film transistors

    SciTech Connect (OSTI)

    Oruc, Feyza B.; Aygun, Levent E.; Donmez, Inci; Biyikli, Necmi; Okyay, Ali K.; Yu, Hyun Yong

    2015-01-01

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

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

    SciTech Connect (OSTI)

    Davidson, Stephen; Sun, Junming; Wang, Yong

    2013-12-02

    A series of ZnO promoted Co/CeO2 catalysts were synthesized and characterized using XRD, TEM, H2-TPR, CO chemisorption, O2-TPO, IR-Py, and CO2-TPD. The effects of ZnO on the catalytic performances of Co/CeO2 were studied in ethanol steam reforming. It was found that the addition of ZnO facilitated the oxidation of Co0 via enhanced oxygen mobility of the CeO2 support which decreased the activity of Co/CeO2 in C–C bond cleavage of ethanol. 3 wt% ZnO promoted Co/CeO2 exhibited minimum CO and CH4 selectivity and maximum CO2 selectivity. This resulted from the combined effects of the following factors with increasing ZnO loading: (1) enhanced oxygen mobility of CeO2 facilitated the oxidation of CHx and CO to form CO2; (2) increased ZnO coverage on CeO2 surface reduced the interaction between CHx/CO and Co/CeO2; and (3) suppressed CO adsorption on Co0 reduced CO oxidation rate to form CO2. In addition, the addition of ZnO also modified the surface acidity and basicity of CeO2, which consequently affected the C2–C4 product distributions.

  10. Photoelectrochemical Stability and Alteration Products of n-Type Single-Crystal ZnO Photoanodes

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

    Paulauskas, I. E.; Jellison, G. E.; Boatner, L. A.; Brown, G. M.

    2011-01-01

    The photoelectrochemical stability and surface-alteration characteristics of doped and undoped n-type ZnO single-crystal photoanode electrodes were investigated. The single-crystal ZnO photoanode properties were analyzed using current-voltage measurements plus spectral and time-dependent quantum-yield methods. These measurements revealed a distinct anodic peak and an accompanying cathodic surface degradation process at negative potentials. The features of this peak depended on time and the NaOH concentration in the electrolyte, but were independent of the presence of electrode illumination. Current measurements performed at the peak indicate that charging and discharging effects are apparently taking place at the semiconductor/electrolyte interface. This result is consistent with themore »significant reactive degradation that takes place on the ZnO single crystal photoanode surface and that ultimately leads to the reduction of the ZnO surface to Zn metal. The resulting Zn-metal reaction products create unusual, dendrite-like, surface alteration structural features that were analyzed using x-ray diffraction, energy-dispersive analysis, and scanning electron microscopy. ZnO doping methods were found to be effective in increasing the n-type character of the crystals. Higher doping levels result in smaller depletion widths and lower quantum yields, since the minority carrier diffusion lengths are very short in these materials.« less

  11. PERFORMANCE OF CdSe TETRAPODS-GOLD AS NANOSTRUCTURE ELECTROCHEMICAL MATERIALS IN PHOTOVOLTAIC CELLS

    E-Print Network [OSTI]

    Natelson, Douglas

    PERFORMANCE OF CdSe TETRAPODS-GOLD AS NANOSTRUCTURE ELECTROCHEMICAL MATERIALS IN PHOTOVOLTAIC CELLS antenna arrays are assembled by coating on CdSe tetrapod templates; the rectifying barrier is formed and reduce the costs associated with conventional solar cells, including multi-bandgap materials [5

  12. Ultrafast Spectroscopy of CdSe Nanocrystals: Morphological and Environmental Effects on Nonradiative and Nonadiabatic Relaxation

    E-Print Network [OSTI]

    Xu, Xianfan

    Ultrafast Spectroscopy of CdSe Nanocrystals: Morphological and Environmental Effects of various morpholo- gies has been demonstrated in CdSe, such as quantum dots (QDs),3 quantum rods (QRs),4 devices and technologies have come to fruition, for example, nanocrystal solar cells (NCSC),7 lasers,8

  13. Duel of the fates: the role of transcriptional circuits and noise in CD4+ cells

    E-Print Network [OSTI]

    Babu, M. Madan

    Duel of the fates: the role of transcriptional circuits and noise in CD4+ cells Daniel Hebenstreit1 , Andrew Deonarine1 , M Madan Babu and Sarah A Teichmann CD4+ T cells play key roles in orchestrating adaptive immune responses, and are a popular model for mammalian cell differentiation. While immune

  14. The transcriptome of human CD34 hematopoietic stem-progenitor cells

    E-Print Network [OSTI]

    cells, including the de novo-generated 3 ESTs and the existing sequences of full-length cDNAs, ESTsThe transcriptome of human CD34 hematopoietic stem-progenitor cells Yeong C. Kima,1 , Qingfa Wua,1 for understanding the genetic basis of hematopoiesis. We analyzed gene expression in human CD34 hematopoietic cells

  15. Photovoltaic cells fabricated by electrophoretic deposition of CdSe nanocrystals

    E-Print Network [OSTI]

    Smith, Nathanael J.

    Photovoltaic cells fabricated by electrophoretic deposition of CdSe nanocrystals Nathanael J. Smith Electrophoretic deposition was used to deposit CdSe nanocrystals on TiO2 for use in photovoltaic cells formed. A solar cell constructed using electrophoretic deposition exhibited a photovoltaic response from

  16. Performance predictions for monolithic, thin-film CdTe/Ge tandem solar cells

    E-Print Network [OSTI]

    Pulfrey, David L.

    Performance predictions for monolithic, thin-film CdTe/Ge tandem solar cells D.L. Pulfrey*, J. Dell): pulfrey@ece.ubc.ca ABSTRACT Cadmium telluride thin-film solar cells are now commercially available be attainable. 1. INTRODUCTION Thin film solar cells based on polycrystalline CdTe have been investigated

  17. Solar Energy Materials & Solar Cells 91 (2007) 13881391 Bifacial configurations for CdTe solar cells

    E-Print Network [OSTI]

    Romeo, Alessandro

    2007-01-01

    Solar Energy Materials & Solar Cells 91 (2007) 1388­1391 Bifacial configurations for CdTe solar Verona, Italy e Department of Electronic and Electrical Engineering, Centre for Renewable Energy Systems We present a different back contact for CdTe solar cell by the application of only a transparent

  18. NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE

    E-Print Network [OSTI]

    Sites, James R.

    NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE M. Gloeckler, A important complications that are often found in experimental CIGS and CdTe solar cells. 1. INTRODUCTION Numerical modeling of polycrystalline thin-film solar cells is an important strategy to test the viability

  19. The role of Erk MAPK pathway in CD4 T cell proliferation and differentiation

    E-Print Network [OSTI]

    Chang, Chiung-Fang

    2011-01-01

    B. (2010). Key role of ERK pathway signaling in lupus.and Hedrick, S.M. The role of Erk MAPK pathway in CD4 T cellTHE DISSERTATION The role of Erk MAPK pathway in CD4 T cell

  20. DISSERTATION Role of the Cu-O Defect in CdTe Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION Role of the Cu-O Defect in CdTe Solar Cells Submitted by Caroline R. Corwine OF THE CU-O DEFECT COMPLEX IN CDTE SOLAR CELLS Thin-film CdTe is one of the leading materials used in photovoltaic (PV) solar cells. One way to improve device performance and stability is through understanding how

  1. THROUGH-THE-GLASS SPECTROSCOPIC ELLIPSOMETRY OF CdTe SOLAR CELLS

    E-Print Network [OSTI]

    Rockett, Angus

    THROUGH-THE-GLASS SPECTROSCOPIC ELLIPSOMETRY OF CdTe SOLAR CELLS Jie Chen 1 , Jian Li 1 , Courtney of the optical structure of CdTe solar cells on transparent conducting oxide (TCO) coated glass superstrates. SE components from the coated glass before solar cell fabrication. A step-by-step fitting procedure identifies

  2. 1. INTRODUCTION Polycrystalline CdTe thin films solar cells have shown long

    E-Print Network [OSTI]

    Romeo, Alessandro

    to the solar panel that can be adapted to any kind of shape and is easy to deploy in space. We have developed ~12% efficiency (AM1.5) CdTe solar cells on glass substrates with a vacuum deposition process [3 in the "superstrate" or "substrate" configuration (see figure 1). High efficiency CdTe solar cells are generally grown

  3. A decrease of circulating CD4? T cells in Attwater's prairie chickens infected with reticuloendotheliosis virus 

    E-Print Network [OSTI]

    Ferro, Pamela Joyce Bloomer

    2001-01-01

    of this project was to develop a method to monitor CD4? and CD8? T cells in prairie chickens and to determine if there was an alteration in the number of circulating T cells associated with REV infection in prairie chickens. A panel of anti-chicken monoclonal...

  4. Synthesis, characterization and performance of Cd1xInxTe compound for solar cell applications

    E-Print Network [OSTI]

    Chow, Lee

    devices, solar energy converters, Videocon devices, sensors, medi- cal imaging and nanodevices [1­11]. CdSynthesis, characterization and performance of Cd1ÀxInxTe compound for solar cell applications Atef), Tebbin, P.O. Box 87 Helwan, Cairo 11412, Egypt b Department of Physics, University of Central Florida

  5. Oxygen Incorporation During Fabrication of Substrate CdTe Photovoltaic Devices: Preprint

    SciTech Connect (OSTI)

    Duenow, J. N.; Dhere, R. G.; Kuciauskas, D.; Li, J. V.; Pankow, J. W.; DeHart, C. M.; Gessert, T. A.

    2012-06-01

    Recently, CdTe photovoltaic (PV) devices fabricated in the nonstandard substrate configuration have attracted increasing interest because of their potential compatibility with flexible substrates such as metal foils and polymer films. This compatibility could lead to the suitability of CdTe for roll-to-roll processing and building-integrated PV. Currently, however, the efficiencies of substrate CdTe devices reported in the literature are significantly lower ({approx}6%-8%) than those of high-performance superstrate devices ({approx}17%) because of significantly lower open-circuit voltage (Voc) and fill factor (FF). In our recent device development efforts, we have found that processing parameters required to fabricate high-efficiency substrate CdTe PV devices differ from those necessary for traditional superstrate CdTe devices. Here, we investigate how oxygen incorporation in the CdTe deposition, CdCl2 heat treatment, CdS deposition, and post-deposition heat treatment affect device characteristics through their effects on the junction. By adjusting whether oxygen is incorporated during these processing steps, we have achieved Voc values greater than 860 mV and efficiencies greater than 10%.

  6. Ion-beam treatment to prepare surfaces of p-CdTe films

    DOE Patents [OSTI]

    Gessert, Timothy A. (Conifer, CO)

    2001-01-01

    A method of making a low-resistance electrical contact between a p-CdTe layer and outer contact layers by ion beam processing comprising: a) placing a CdS/CdTe device into a chamber and evacuating the chamber; b) orienting the p-CdTe side of the CdS/CdTe layer so that it faces apparatus capable of generating Ar atoms and ions of preferred energy and directionality; c) introducing Ar and igniting the area of apparatus capable of generating Ar atoms and ions of preferred energy and directionality in a manner so that during ion exposure, the source-to-substrate distance is maintained such that it is less than the mean-free path or diffusion length of the Ar atoms and ions at the vacuum pressure; d) allowing exposure of the p-CdTe side of the device to said ion beam for a period less than about 5 minutes; and e) imparting movement to the substrate to control the real uniformity of the ion-beam exposure on the p-CdTe side of the device.

  7. Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells , Ana Kanevce2

    E-Print Network [OSTI]

    Sites, James R.

    Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells Tao Song1 , Ana Kanevce2Te solar cell performance is limited by recombination at the grain boundaries, low carrier density (p is not strongly affected until b exceeds 0.4 eV. Index Terms -- device modeling, solar cells, epitaxial CdTe. I

  8. Fluorescence quenching of CdSe quantum dots on graphene

    SciTech Connect (OSTI)

    Guo, Xi Tao; Hua Ni, Zhen, E-mail: zhni@seu.edu.cn; Yan Nan, Hai; Hui Wang, Wen [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China)] [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China); Yan Liao, Chun [Physics Department, National Photoelectric Technology and Functional Materials and Application of Science and Technology International Cooperation Base, Northwest University, Xi'an 710069 (China)] [Physics Department, National Photoelectric Technology and Functional Materials and Application of Science and Technology International Cooperation Base, Northwest University, Xi'an 710069 (China); Zhang, Yan; Wei Zhao, Wei [Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China)] [Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China)

    2013-11-11

    We studied systematically the fluorescence quenching of CdSe quantum dots (QDs) on graphene and its multilayers, as well as graphene oxide (GO) and reduced graphene oxide (rGO). Raman intensity of QDs was used as a quantitatively measurement of its concentration in order to achieve a reliable quenching factor (QF). It was found that the QF of graphene (?13.1) and its multilayers is much larger than rGO (?4.4), while GO (?1.5) has the lowest quenching efficiency, which suggests that the graphitic structure is an important factor for quenching the fluorescence of QDs. It was also revealed that the QF of graphene is not strongly dependent on its thicknesses.

  9. Growth of CdTe thin films on graphene by close-spaced sublimation method

    SciTech Connect (OSTI)

    Jung, Younghun; Yang, Gwangseok; Kim, Jihyun, E-mail: hyunhyun7@korea.ac.kr [Department of Chemical and Biological Engineering, Korea University, Seoul 136-701 (Korea, Republic of)] [Department of Chemical and Biological Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Chun, Seungju; Kim, Donghwan [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of)] [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2013-12-02

    CdTe thin films grown on bi-layer graphene were demonstrated by using the close-spaced sublimation method, where CdTe was selectively grown on the graphene. The density of the CdTe domains was increased with increasing the number of the defective sites in the graphene, which was controlled by the duration of UV exposure. The CdTe growth rate on the bi-layer graphene electrodes was 400?nm/min with a bandgap energy of 1.45–1.49?eV. Scanning electron microscopy, micro-Raman spectroscopy, micro-photoluminescence, and X-ray diffraction technique were used to confirm the high quality of the CdTe thin films grown on the graphene electrodes.

  10. Surface Plasmon Excitation via Au Nanoparticles in CdSe Semiconductor

    SciTech Connect (OSTI)

    Pradhan, A. K.; Konda, R. B.; Mundle, R.; Mustafa, H.; Bamiduro, O.; Roy, U. N.; Cui, Y.; Burger, A.

    2008-10-23

    We present experimental evidence for the large Raman and photoluminescence enhancement in CdSe semiconductor films grown on Si and glass substrates due to excitation of surface plasmon resonances in proximate gold metal nanoparticles deposited on the surface of CdSe film. Heterojunction diodes containing n-CdSe on p-Si semiconductor were fabricated and the surface of the diodes was in situ coated with Au nanoparticles using the ultra-high vacuum pulsed-laser deposition technique. A significant enhancement of the photocurrent was obtained in CdSe/p-Si containing Au nanoparticles on the surface compared to CdSe/p-Si due to the enhanced photo-absorption within the semiconductor by the phenomenon of surface plasmon resonance. These observations suggest a variety of approaches for improving the performance of devices such as photodetectors, photovoltaic, and related devices, including biosensors.

  11. Charge transfer and mobility enhancement at CdO/SnTe heterointerfaces

    SciTech Connect (OSTI)

    Nishitani, Junichi; Yu, Kin Man; Walukiewicz, Wladek

    2014-09-29

    We report a study of the effects of charge transfer on electrical properties of CdO/SnTe heterostructures. A series of structures with variable SnTe thicknesses were deposited by RF magnetron sputtering. Because of an extreme type III band offset with the valence band edge of SnTe located at 1.5?eV above the conduction band edge of CdO, a large charge transfer is expected at the interface of the CdO/SnTe heterostructure. The electrical properties of the heterostructures are analyzed using a multilayer charge transport model. The analysis indicates a large 4-fold enhancement of the CdO electron mobility at the interface with SnTe. The mobility enhancement is attributed to reduction of the charge center scattering through neutralization of the donor-like defects responsible for the Fermi level pinning at the CdO/SnTe interface.

  12. H2S removal with ZnO during fuel processing for PEM fuel cell applications

    SciTech Connect (OSTI)

    Li, Liyu; King, David L.

    2006-09-15

    The possibility of using ZnO as a H2S absorbent to protect catalysts in the gasoline and diesel fuel processor for PEM fuel cell applications was studied. It is possible to use commercial ZnO absorbent as a guard bed to protect the PROX catalyst and PEM fuel cell. However, it is not feasible to use ZnO to protect high and low temperature WGS catalysts, most likely due to COS formation via reactions CO + H2S = COS + H2 and CO2 + H2S = COS + H2O.

  13. Phosphorescence quenching by mechanical stimulus in CaZnOS:Cu

    SciTech Connect (OSTI)

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

    2014-07-07

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

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

    SciTech Connect (OSTI)

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

    2015-01-01

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

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

    SciTech Connect (OSTI)

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

    2014-01-28

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

  16. Structural studies and band gap tuning of Cr doped ZnO nanoparticles

    SciTech Connect (OSTI)

    Srinet, Gunjan Kumar, Ravindra Sajal, Vivek

    2014-04-24

    Structural and optical properties of Cr doped ZnO nanoparticles prepared by the thermal decomposition method are presented. X-ray diffraction studies confirmed the substitution of Cr on Zn sites without changing the wurtzite structure of ZnO. Modified form of W-H equations was used to calculate various physical parameters and their variation with Cr doping is discussed. Significant red shift was observed in band gap, i.e., a band gap tuning is achieved by Cr doping which could eventually be useful for optoelectronic applications.

  17. Inverse spin Hall effect induced by spin pumping into semiconducting ZnO

    SciTech Connect (OSTI)

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

    2014-02-03

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

  18. X-ray absorption studies of mixed salt polymer electrolytes: ZnBr{sub 2}/CaBr{sub 2}-PEO, ZnBr{sub 2}/LiBr-PEO, and ZnBr{sub 2}/RbBr-PEO complexes

    SciTech Connect (OSTI)

    McBreen, J.; Yang, X.Q.; Lee, H.S.; Okamoto, Y.

    1995-02-01

    Polyethylene oxide (PEO)-salt systems are an important new class of electrolytes that are being considered for many uses. X-ray absorption (XAS) studies of ZnBr{sub 2}-PEO complexes, at the Zn K edge, at temperatures between 25 and 120 C, indicate that additions of bromide salts of Li, Rb, or Ca result in the formation of ZnBr{sub 4}{sup {minus} 2} complexes with a Zn-Br bond length of 2.42 {angstrom}. XAS, at the Rb K edge, in mixed RbBr/ZnBr{sub 2}-PEO complexes with an excess of ZnBr{sub 2}, shows that the ZnBr{sub 2} causes the RbBr to dissolve in the polymer. The Rb{sup +} ions are weakly complexed with the PEO with an Rb-O bond distance of 2.93 {angstrom}.

  19. The structural, electrical, and optical properties of hydrogenated chromium-doped CdO films

    SciTech Connect (OSTI)

    Dakhel, A.A.; Hamad, H.

    2013-12-15

    Cadmium oxide thin films doped with different amounts of chromium and annealed in hydrogen atmosphere have been grown on glass substrates by means of physical vapour deposition (PVD) method. The structural, electrical, and optical properties of the prepared Cr-doped CdO (CdO:Cr–H) films were systematically studied. The structural investigations show that the incorporated Cr ions mainly occupied locations in interstitial positions of CdO lattice. The bandgap engineer by Cr incorporation and hydrogenation were studied. The variations of the electrical parameters of CdO:Cr–H films with Cr incorporation and hydrogenation were investigated. It was established that among the investigated samples, the largest mobility and conductivity were measured with 1.5%:Cr–H film. Therefore, hydrogenated CdO:Cr films can be effectively used in different applications of near infrared-transparent-conducting-oxide (NIR-TCO). - Graphical abstract: Optoelectronic properties of synthesised chromium-doped CdO thin films. It was established that the largest mobility (53.4 cm{sup 2}/V.s) and conductivity (2136.8 S/cm) were measured in 1.5%:Cr–H doped CdO film. Therefore, such films can be effectively used in near infrared-transparent-conducting-oxide (NIR-TCO). - Highlights: • The properties of CdO films annealed in H{sub 2} gas were systematically studied. • Cr{sup 3+} ions most likely occupied interstitial locations in CdO lattice and as donors. • Improvement of conductivity parameters with Cr doping and H annealing. • Bandgap narrowing observed with Cd-doping.

  20. The role of Id2 and Id3 in memory CD8? T cells differentiation and natural killer T cell homeostasis

    E-Print Network [OSTI]

    Yang, Cliff Yang

    2012-01-01

    of NK1.1 + TCR? + or CD1d tetramer + NKT cells for indicatedof ?GalCer-loaded CD1d tetramer + NKT cells for indicated?GalCer-loaded CD1d tetramer, then examined for expression

  1. 1 Age-dependent regulation of skeletal muscle mitochondria by the thrombospondin-1 2 receptor CD47

    E-Print Network [OSTI]

    Frazier, William A.

    -null mice 35displayed enhanced treadmill endurance relative to WTs and CD47-null gastrocnemius had twitch pattern in 39gastrocnemius. Both CD47 and TSP1 null mice are leaner than WTs, use less oxygen

  2. A genome-wide regulatory network identifies key transcription factors for memory CD8[superscript +] T-cell development

    E-Print Network [OSTI]

    Hu, Guangan

    Memory CD8[superscript +] T-cell development is defined by the expression of a specific set of memory signature genes. Despite recent progress, many components of the transcriptional control of memory CD8[superscript +] ...

  3. A novel CD93 polymorphism in non-obese diabetic (NOD) and NZB/W F1 mice is linked to a CD4+ iNKT cell deficient state

    E-Print Network [OSTI]

    2010-01-01

    found B6 CD93 ?/? and B6. NOD Idd13 mice to be susceptibleCD4 + NKT cells. Keywords NOD mice . Idd13 . NZB/W F1 mice .Abbreviations BM TR MZ iNKT cell NOD DN CD4SP Idd alpha-

  4. A novel CD93 polymorphism in non-obese diabetic (NOD) and NZB/W F1 mice is linked to a CD4+ iNKT cell deficient state

    E-Print Network [OSTI]

    2010-01-01

    PE conjugated CD1d tetramer loaded with PBS-57 (Alpha-was prepared by the NIH Tetramer Facility. A total of 1–2 ×CD3 lo , PBS57-loaded CD1d Tetramer+) in the liver of B6 (n=

  5. Chemical composition and some trace element contents in coals and coal ash from Tamnava-Zapadno Polje Coal Field, Serbia

    SciTech Connect (OSTI)

    Vukasinovic-Pesic, V.; Rajakovic, L.J. [University of Montenegro, Podgorica (Montenegro)

    2009-07-01

    The chemical compositions and trace element contents (Zn, Cu, Co, Cr, Ni, Pb, Cd, As, B, Hg, Sr, Se, Be, Ba, Mn, Th, V, U) in coal and coal ash samples from Tamnava-Zapadno Polje coal field in Serbia were studied. The coal from this field belongs to lignite. This high volatility coal has high moisture and low S contents, moderate ash yield, and high calorific value. The coal ash is abundant in alumosilicates. Many trace elements such as Ni > Cd > Cr > B > As > Cu > Co > Pb > V > Zn > Mn in the coal and Ni > Cr > As > B > Cu > Co = Pb > V > Zn > Mn in the coal ash are enriched in comparison with Clarke concentrations.

  6. PROJECT PROFILE: Defining the Defect Chemistry and Structural Properties Required for 24%-Efficient CdTe Devices

    Broader source: Energy.gov [DOE]

    While crystalline silicon accounted for two thirds of the photovoltaic (PV) market in 2014, cadmium telluride (CdTe) PV modules are becoming increasingly competitive with continued improvements in efficiency and reduction in price. This project will enable 24% efficient CdTe cells by improving the defect chemistry and structural properties of polycrystalline cadmium telluride (CdTe) necessary to overcome photovoltage barriers, the main hurdle to higher efficiency of commercial CdTe PV.

  7. Sympathetic cooling of trapped Cd B. B. Blinov,* L. Deslauriers, P. Lee, M. J. Madsen, R. Miller, and C. Monroe

    E-Print Network [OSTI]

    Monroe, Christopher

    Sympathetic cooling of trapped Cd¿ isotopes B. B. Blinov,* L. Deslauriers, P. Lee, M. J. Madsen, R 48109-1120 Received 6 December 2001; published 10 April 2002 We sympathetically cool a trapped 112 Cd ion by directly Doppler cooling a 114 Cd ion in the same trap. This is the first demonstration

  8. Instructions on How to Request Publications NIST Weights and Measures Page 1 of 4 CD9001 August 2014

    E-Print Network [OSTI]

    Instructions on How to Request Publications NIST Weights and Measures Page 1 of 4 CD9001 ­ August://tsapps.nist.gov/WMD/default.aspx #12;Instructions on How to Request Publications NIST Weights and Measures Page 2 of 4 CD9001 ­ August. #12;Instructions on How to Request Publications NIST Weights and Measures Page 3 of 4 CD9001 ­ August

  9. High Efficiency Thin Film CdTe and a-Si Based Solar Cells Annual Technical Report for the Period

    E-Print Network [OSTI]

    Deng, Xunming

    High Efficiency Thin Film CdTe and a-Si Based Solar Cells Annual Technical Report for the Period This report covers the second year of this subcontract for research on high efficiency CdTe-based thin-film solar cells and on high efficiency a-Si-based thin-film solar cells. The effort on CdTe- based materials

  10. Cell-intrinsic Transforming Growth Factor-[beta] signaling mediates virus-specific CD8? T cell deletion and lymphocytic choriomeningitis virus persistence in vivo

    E-Print Network [OSTI]

    Tinoco, Roberto

    2010-01-01

    Persistent numbers of tetramer+ CD8(+) T cells, but loss ofepitopes were monitored by tetramer staining throughout theof peripheral blood tetramer-positive CD8 + T cells were

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

    SciTech Connect (OSTI)

    Grinblat, Gustavo; Comedi, David; Bern, Francis; Barzola-Quiquia, José; Esquinazi, Pablo; Tirado, Mónica

    2014-03-10

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

  12. Development of ZnO Based Light Emitting Diodes and Laser Diodes

    E-Print Network [OSTI]

    Kong, Jieying

    2012-01-01

    E. Fred Schubert, Light-Emitting Diodes, New York (2006) [8]ZnO homojunction light emitting diode 3. 1. Motivation ofAlGaAs red light-emitting diodes, in: G.B. Stringfellow, M.

  13. Multianalyte biosensor based on pH-sensitive ZnO electrolyte–insulator–semiconductor structures

    SciTech Connect (OSTI)

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

    2014-05-14

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

  14. ZnO nanowires on glass via chemical routes: A prospective photocatalyst for indoors applications

    E-Print Network [OSTI]

    O:Al Seed layer Photocatalysis Stearic acid A B S T R A C T Versatile ZnO nanowires with controlled applications. ã 2014 Elsevier Ltd. All rights reserved. Introduction Heterogeneous photocatalysis is attracting

  15. Imaging and characterization of piezoelectric potential in a single bent ZnO microwire

    SciTech Connect (OSTI)

    Wang, Chiang-Lun; Chen, Jhih-Wei; Chen, Yi-Chun; Wu, Chung-Lin, E-mail: clwuphys@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Tsai, Shu-Ju [Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 70101, Taiwan (China); Shiu, Hong-Wei; Chang, Lo-Yueh; Chen, Chia-Hao [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China); Lin, Kai-Hsiang; Hsu, Hsu-Cheng [Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2014-09-22

    We achieved direct visualization of the piezoelectric potentials in a single bent ZnO microwire (MW) using focused synchrotron radiation (soft x-ray) scanning photoelectron spectro-microscopy. Using radial-line scan across the bent section of ZnO MW, the characteristic core-level shifts were directly related to the spatial distribution of piezoelectric potentials perpendicular to the ZnO polar direction. Using piezoelectric modeling in ZnO, we delineated the band structure distortion and carrier concentration change from tensile to compressed sides by combining the spatial resolved cathodoluminescence characteristics in an individual microwire. This spectro-microscopic technique allows imaging and identification of the electric-mechanical couplings in piezoelectric micro-/nano-wire systems.

  16. Nitrogen-Doped ZnO Nanowire Arrays for Photoelectrochemical Water Splitting

    E-Print Network [OSTI]

    Li, Yat

    . ZnO is a direct bandgap semiconductor with similar bandgap and band edge positions as TiO2 nanosheets,15 nanotubes,16 and nanorods,17,18 as they offer advantages over their bulk counterparts

  17. Synthesis of ZnO decorated graphene nanocomposite for enhanced photocatalytic properties

    SciTech Connect (OSTI)

    Gayathri, S.; Jayabal, P.; Kottaisamy, M.; Ramakrishnan, V.

    2014-05-07

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

  18. Single-valley quantum Hall ferromagnet in a dilute MgxZn1-xO/ZnO strongly correlated two-dimensional electron system

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

    Kozuka, Y.; Tsukazaki, A.; Maryenko, D.; Falson, J.; Bell, C.; Kim, M.; Hikita, Y.; Hwang, H. Y.; Kawasaki, M.

    2012-02-03

    We investigate the spin susceptibility (g*m*) of dilute two-dimensional (2D) electrons confined at the MgxZn1-xO/ZnO heterointerface. Magnetotransport measurements show a four-fold enhancement of g*m*, dominated by the increase in the Landé g-factor. The g-factor enhancement leads to a ferromagnetic instability of the electron gas as evidenced by sharp resistance spikes. At high magnetic field, the large g*m* leads to full spin polarization, where we found sudden increase in resistance around the filling factors of half-integer, accompanied by complete disappearance of fractional quantum Hall (QH) states. Along with its large effective mass and the high electron mobility, our result indicates thatmore »the ZnO 2D system is ideal for investigating the effect of electron correlations in the QH regime.« less

  19. Zn speciation in a soil contaminated by the deposition of a dredged sediment by synchrotron X-ray techniques

    SciTech Connect (OSTI)

    Isaure, Marie-Pierre; Manceau, Alain; Laboudigue, Agnes; Tamura, Nobumichi; Marcus, Matthew A.

    2003-09-01

    The nature and proportion of Zn species present in an agricultural soil overlaid by a dredged contaminated sediment have been untangled by the novel combination of three non-invasive synchrotron-based x-ray techniques: x-ray microfluorescence ({mu}SXRF), microdiffraction ({mu}XRD), and absorption spectroscopy (EXAFS). One primary (franklinite) and two secondary (phyllomanganate and phyllosilicate) Zn-containing minerals were identified in the initial soil, and another primary (ZnS) and a new secondary (Fe-(oxyhydr)oxide) Zn species in the covered soil. The quantitative analysis of EXAFS spectra recorded on bulk samples indicated that ZnS and Zn-Fe (oxyhydr)oxides amounted to 71+-10 percent and 27+-10 percent, respectively, and the other Zn species to less than 10 percent. The two new Zn species found in the covered soil result from the gravitational migration of ZnS particles initially present in the sediment, and from their further oxidative dissolution and fixation of leached Zn on F e (oxyhydr) oxides.

  20. Determination of reactive oxygen species from ZnO micro-nano structures with shape-dependent photocatalytic activity

    SciTech Connect (OSTI)

    He, Weiwei; Zhao, Hongxiao; Jia, Huimin; Yin, Jun-Jie; Zheng, Zhi

    2014-05-01

    Graphical abstract: ZnO micro/nano structures with shape dependent photocatalytic activity were prepared by hydrothermal reaction. The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were identified precisely by electron spin resonance spectroscopy. The type of reactive oxygen species was determined by band gap structure of ZnO. - Highlights: • ZnO micro/nano structures with different morphologies were prepared by solvothermal reaction. • Multi-pod like ZnO structures exhibited superior photocatalytic activity. • The generations of hydroxyl radical, superoxide and singlet oxygen from irradiated ZnO were characterized precisely by electron spin resonance spectroscopy. • The type of reactive oxygen species was determined by band gap structure of ZnO. - Abstract: ZnO micro/nano structures with different morphologies have been prepared by the changing solvents used during their synthesis by solvothermal reaction. Three typical shapes of ZnO structures including hexagonal, bell bottom like and multi-pod formed and were characterized by scanning electron microscopy and X-ray diffraction. Multi pod like ZnO structures exhibited the highest photocatalytic activity toward degradation of methyl orange. Using electron spin resonance spectroscopy coupled with spin trapping techniques, we demonstrate an effective way to identify precisely the generation of hydroxyl radicals, superoxide and singlet oxygen from the irradiated ZnO multi pod structures. The type of reactive oxygen species formed was predictable from the band gap structure of ZnO. These results indicate that the shape of micro-nano structures significantly affects the photocatalytic activity of ZnO, and demonstrate the value of electron spin resonance spectroscopy for characterizing the type of reactive oxygen species formed during photoexcitation of semiconductors.