Sample records for gallium diselenide cigs

  1. Electrical Bias as an Alternate Method for Reproducible Measurement of Copper Indium Gallium Diselenide (CIGS) Photovoltaic Modules: Preprint

    SciTech Connect (OSTI)

    Deline, C.; Stokes, A.; Silverman, T. J.; Rummel, S.; Jordan, D.; Kurtz, S.

    2012-08-01T23:59:59.000Z

    Light-to-dark metastable changes in thin-film photovoltaic (PV) modules can introduce uncertainty when measuring module performance on indoor flash testing equipment. This study describes a method to stabilize module performance through forward-bias current injection rather than light exposure. Measurements of five pairs of thin-film copper indium gallium diselenide (CIGS) PV modules indicate that forward-bias exposure maintained the PV modules at a stable condition (within 1%) while the unbiased modules degraded in performance by up to 12%. It was additionally found that modules exposed to forward bias exhibited stable performance within about 3% of their long-term outdoor exposed performance. This carrier-injection method provides a way to reduce uncertainty arising from fast transients in thin-film module performance between the time a module is removed from light exposure and when it is measured indoors, effectively simulating continuous light exposure by injecting minority carriers that behave much as photocarriers do. This investigation also provides insight into the initial light-induced transients of thin-film modules upon outdoor deployment.

  2. Preparation Of Copper Indium Gallium Diselenide Films For Solar Cells

    DOE Patents [OSTI]

    Bhattacharya, Raghu N. (Littleton, CO); Contreras, Miguel A. (Golden, CO); Keane, James (Lakewood, CO); Tennant, Andrew L. (Denver, CO), Tuttle, John R. (Denver, CO); Ramanathan, Kannan (Lakewood, CO); Noufi, Rommel (Golden, CO)

    1998-08-08T23:59:59.000Z

    High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

  3. Long-Term Performance Data and Analysis of CIS/CIGS Modules Deployed Outdoors

    SciTech Connect (OSTI)

    del Cueto, J.A.; Rummel, S.; Kroposki, B.; Anderberg, A.

    2008-11-01T23:59:59.000Z

    The long-term performance data of copper indium diselenide (CIS) and gallium-alloyed CIS (CIGS) photovoltaic (PV) modules are investigated to assess the reliability of this technology.

  4. Long-Term Performance Data and Analysis of CIS/CIGS Modules Deployed Outdoors (Presentation)

    SciTech Connect (OSTI)

    del Cueto, J. A.; Kroposki, B.; Rummel, S.; Anderberg, A.

    2008-08-10T23:59:59.000Z

    The long-term performance data of copper indium diselenide (CIS) and gallium-alloyed CIS (CIGS) photovoltaic (PV) modules are investigated to assess the reliability of this technology.

  5. NREL scientists develop robust, high-performance IZO transparent contact for CIGS solar cells.

    E-Print Network [OSTI]

    NREL scientists develop robust, high-performance IZO transparent contact for CIGS solar cells indium gallium diselenide (CIGS) solar cell is zinc oxide (ZnO). The problem is that unprotected Zn is a lifetime-limiting problem that is currently addressed solely through encapsulation. Fundamentally improving

  6. Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

    DOE Patents [OSTI]

    Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

    2014-11-04T23:59:59.000Z

    Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

  7. Sputtered Molybdenum Bilayer Back Contact for Copper Indium Diselenide-Based Polycrystalline Thin-Film Solar Cells

    E-Print Network [OSTI]

    Scofield, John H.

    of the CIS or CIGS solar cell structure (not to scale). In these investigations, however, the metal layers-Film Solar Cells John H. Scofield1, A. Duda, and D. Albin National Renewable Energy Laboratory, 1617 Cole-of-the-art polycrystalline copper indium gallium diselenide solar cells with good results. Thin Solid Films, 260 (1), pp. 26

  8. Preparation of copper-indium-gallium-diselenide precursor films by electrodeposition for fabricating high efficiency solar cells

    DOE Patents [OSTI]

    Bhattacharya, Raghu N. (Littleton, CO); Hasoon, Falah S. (Arvada, CO); Wiesner, Holm (Golden, CO); Keane, James (Lakewood, CO); Noufi, Rommel (Golden, CO); Ramanathan, Kannan (Golden, CO)

    1999-02-16T23:59:59.000Z

    A photovoltaic cell exhibiting an overall conversion efficiency of 13.6% is prepared from a copper-indium-gallium-diselenide precursor thin film. The film is fabricated by first simultaneously electrodepositing copper, indium, gallium, and selenium onto a glass/molybdenum substrate (12/14). The electrodeposition voltage is a high frequency AC voltage superimposed upon a DC voltage to improve the morphology and growth rate of the film. The electrodeposition is followed by physical vapor deposition to adjust the final stoichiometry of the thin film to approximately Cu(In.sub.1-n Ga.sub.x)Se.sub.2, with the ratio of Ga/(In+Ga) being approximately 0.39.

  9. Synthesis, characterization, and exciton dynamics of II-VI semiconducting nanomaterials and ab-initio studies for applications in explosives sensing

    E-Print Network [OSTI]

    Cooper, Jason Kyle

    2013-01-01T23:59:59.000Z

    gallium diselenide (CIGS) solar cells were studied. TheCIGS (copper indium gallium diselenide) thin film solar cells

  10. Commercialization of High Efficiency Low Cost CIGS Technology Based on Electroplating: Final Technical Progress Report, 28 September 2007 - 30 June 2009

    SciTech Connect (OSTI)

    Basol, B.

    2010-08-01T23:59:59.000Z

    This report describes SoloPower's work as a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's Solar Energy Technologies Program. The term of this subcontract with the National Renewable Energy Laboratory was two years. The project focused on SoloPower's electrodeposition-based copper indium gallium (di)selenide (CIGS) technology. Under this subcontract, SoloPower improved the quality of its flexible metal substrates, increased the size of its solar cells from 0.5 cm2 to 120 cm2, increased the small-area cell efficiencies from near 11% to near 14%, demonstrated large-area cells, and developed a module manufacturing process.

  11. Exploration of Novel Reaction Pathway for Formation of Copper Indium Gallium Diselenide: Cooperative Research and Development Final Report, CRADA Number CRD-03-121

    SciTech Connect (OSTI)

    van Hest, M.

    2014-11-01T23:59:59.000Z

    The investigation will explore a potentially low-cost method of forming CIGS for use in solar cells. Investigators from HelioVolt will work in NREL laboratories to modify and apply our tools in fabrication of the CIGS layer. Investigators from NREL will assist in preparing substrates and in compleing solar cells composed of these CIGS layers to evaluate the effectiveness of the HelioVolt processes.

  12. Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report

    SciTech Connect (OSTI)

    Britt, J.; Wiedeman, S.; Albright, S.

    2000-11-09T23:59:59.000Z

    As a technology partner with NREL, Global Solar Energy (GSE) has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) based on copper indium gallium diselenide (CIGS). The distinguishing feature of the GSE manufacturing process is the exclusive use of lightweight, flexible substrates. GSE has developed the technology to fabricate CIGS photovoltaics on both stainless-steel and polymer substrates. CIGS deposited on flexible substrates can be fabricated into either flexible or rigid modules. Low-cost, rigid PV panels for remote power, bulk/utility, telecommunication, and rooftop applications have been produced by affixing the flexible substrate to an inexpensive rigid panel by lamination or adhesive. Stainless-steel-based PV modules are fabricated by a novel interconnect method that avoids the use of wires or foils and soldered connections. In the case of polymer-based PV modules, the continuous roll is not sectioned into individual panels until the module buss and power leads are attached. Roll-to-roll vacuum deposition has several advantages that translate directly to reduced capital costs, greater productivity, improved yield, greater reliability, lower maintenance, and a larger volume of PV material. In combination with roll-to-roll processing, GSE has developed evaporation deposition operations that enable low-cost and high-efficiency CIGS modules. The CIGS deposition process relies heavily on effusion source technology developed at GSE, and solving numerous problems was an integral part of the source development effort. Cell interconnection for thin-film CIGS modules on a polyimide substrate presents a considerable challenge.

  13. Preparation of CIGS-based solar cells using a buffered electrodeposition bath

    DOE Patents [OSTI]

    Bhattacharya, Raghu Nath (Littleton, CO)

    2007-11-20T23:59:59.000Z

    A photovoltaic cell exhibiting an overall conversion efficiency of at least 9.0% is prepared from a copper-indium-gallium-diselenide thin film. The thin film is prepared by simultaneously electroplating copper, indium, gallium, and selenium onto a substrate using a buffered electro-deposition bath. The electrodeposition is followed by adding indium to adjust the final stoichiometry of the thin film.

  14. Copper Indium Gallium Diselenide | Department of Energy

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

    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 DataDepartment of Energy Your Density Isn't Your Destiny: Theof"Wave theJuly 30, 2013Department of Energy CoordinatingPhotovoltaics

  15. Design and Synthesis of Plasmonic Core/Shell Nanorods for Light Trapping in Organic Photo-Voltaics, Non-Linear Optics and Photo-Thermal Tumor Therapy

    E-Print Network [OSTI]

    Jankovic, Vladan

    2013-01-01T23:59:59.000Z

    solar cells, developed in the 1980s and based on amorphous or polycrystalline silicon (Si), copper indium gallium (di)selenide (CIGS), and

  16. 2011 Minerals Yearbook U.S. Department of the Interior

    E-Print Network [OSTI]

    Cs) and optoelectronic devices [laser diodes, light-emitting diodes (lEDs), photodetectors, and solar cells]. Gallium solar energy systems by about 75%, and thereby allow copper-indium-gallium diselenide (CiGS) solar

  17. Diffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells

    E-Print Network [OSTI]

    Rockett, Angus

    conversion efficiency of solar cells made from this material [1]. One of the special qualities of the CIGS improve the solar cell performance. In many of the different CIGS fabrication techniques, an in depthDiffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells O. Lundberga,*, J. Lua , A

  18. Barrier Coatings for Thin Film Solar Cells: Final Subcontract Report, September 1, 2002 -- January 30, 2008

    SciTech Connect (OSTI)

    Olsen, L. C.

    2010-03-01T23:59:59.000Z

    This program has involved investigations of the stability of CdTe and copper-indium-gallium-diselenide (CIGS) solar cells under damp heat conditions and effects of barrier coatings.

  19. Journal of Crystal Growth 310 (2008) 29872994 Reaction kinetics of CuGaSe2 formation from

    E-Print Network [OSTI]

    Anderson, Timothy J.

    2008-01-01T23:59:59.000Z

    of polycrystalline thin-film Cu(InxGa1Àx)Se2 (CIGS) solar cells achieved over the past several decades appears. Copper gallium diselenide; B3. Solar cells 1. Introduction The continuous improvement in the efficiency for the top cell in a CIGS tandem structure [2­4], given its suitable band gap energy (1.68 eV), process

  20. (Data in metric tons unless otherwise noted) Domestic Production and Use: Indium was not recovered from ores in the United States in 2007. Indium-containing

    E-Print Network [OSTI]

    were exported to Canada for processing. Two companies, one in New York and the other in Rhode Island gallium diselenide (CIGS) solar cells require approximately 50 metric tons of indium to produce 1 gigawatt of solar power. Research was underway to develop a low-cost manufacturing process for flexible CIGS solar

  1. Effects of Metastabilities on CIGS Photovoltaic Modules

    Broader source: Energy.gov [DOE]

    This poster describes a SunShot Initiative solar project led by a team from Nexcis Photovoltaic Technology entitled "Effects of Metastabilities on CIGS Photovoltaic Modules." The team studied the driving force of the mechanisms which governs the different observed phases during storage, light exposition and annealing. The aim of this study is to obtain a better understanding of this phenomenon and hence a better evaluation of its impact on solar panel reliability.

  2. Stress Induced Degradation Modes in CIGS Mini-Modules: Preprint

    SciTech Connect (OSTI)

    Kempe, M. D.; Terwilliger, K. M.; Tarrant, D.

    2008-05-01T23:59:59.000Z

    This study demonstrates that the method of encapsulation can affect the long-term stability of CIGS modules, principally through interactions with the ZnO.

  3. CIGS Material and Device Stability: A Processing Perspective (Presentation)

    SciTech Connect (OSTI)

    Ramanathan, K.

    2012-03-01T23:59:59.000Z

    This is a general overview of CIGS material and device fundamentals. In the first part, the basic features of high efficiency CIGS absorbers and devices are described. In the second part, some examples of previous collaboration with Shell Solar CIGSS graded absorbers and devices are shown to illustrate how process information was used to correct deviations and improve the performance and stability.

  4. Method of junction formation for CIGS photovoltaic devices

    DOE Patents [OSTI]

    Delahoy, Alan E. (Rocky Hill, NJ)

    2010-01-26T23:59:59.000Z

    Sulfur is used to improve the performance of CIGS devices prepared by the evaporation of a single source ZIS type compound to form a buffer layer on the CIGS. The sulfur may be evaporated, or contained in the ZIS type material, or both. Vacuum evaporation apparatus of many types useful in the practice of the invention are known in the art. Other methods of delivery, such as sputtering, or application of a thiourea solution, may be substituted for evaporation.

  5. Method of junction formation for CIGS photovoltaic devices

    DOE Patents [OSTI]

    Delahoy, Alan E.

    2006-03-28T23:59:59.000Z

    Sulfur is used to improve the performance of CIGS devices prepared by the evaporation of a single source ZIS type compound to form a buffer layer on the CIGS. The sulfur may be evaporated, or contained in the ZIS type material, or both. Vacuum evaporation apparatus of many types useful in the practice of the invention are known in the art. Other methods of delivery, such as sputtering, or application of a thiourea solution, may be substituted for evaporation.

  6. John Tyler McGoffin 830 Mathews St. jtmcgoffin@gmail.com Fort Collins, CO 80521

    E-Print Network [OSTI]

    Sites, James R.

    and Characterization of Thin Film photovoltaic devices including Current Density Voltage (JV), Quantum Efficiency (QETe) and Copper Indium Gallium diSelenide (CIGS) thin film photovoltaic devices using Close Space Sublimation (CSS approachable and easy to talk to #12;Employment: Founder January 2014 - Present Photovoltaic Imaging Systems

  7. 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1wileyonlinelibrary.com COMMUNICATION

    E-Print Network [OSTI]

    .88% Efficient Tin Sulfide Solar Cells using Congruent Thermal Evaporation Vera Steinmann,* R. Jaramillo, Katy reported PCE for TE SnS solar cells is 1.6%, with a small device area of 0.01 cm2.[10] The cur- rent Sn-per-year (GW/yr) levels,[1] while PV cells based on copper (indium, gallium) (diselenide, disulfide) (CIGS

  8. Effects of Series Resistance and Inductance on Solar Cell Admittance Measurements(a)

    E-Print Network [OSTI]

    Scofield, John H.

    on a variety of 0.43 cm2 area, copper indium gallium diselenide (CIGS) polycrystalline thin film solar cellsEffects of Series Resistance and Inductance on Solar Cell Admittance Measurements(a) John H Energy Materials and Solar Cells on April 17, 1994) Admittance measurements have been performed

  9. When you think of the film industry, what comes to mind? Entertainment. In this issue you will discover how films not only bring us the latest adventures but also are being sculptured at

    E-Print Network [OSTI]

    Demirel, Melik C.

    rooftop market. Solyndra uses a copper-indium-gallium-diselenide (CIGS) absorber layer in its solar cell to create revolutionary optics, semiconductors, medical devices, and solar cells. Spring 2009 In This Issue information, visit: www.jbg3.net Alumni Spotlight Phil Kraus (B.S. '93) is the director of technology at solar-cell

  10. Progress Toward a Stabilization and Preconditioning Protocol for Polycrystalline Thin-Film Photovoltaic Modules

    SciTech Connect (OSTI)

    del Cueto, J. A.; Deline, C. A.; Rummel, S. R.; Anderberg, A.

    2010-08-01T23:59:59.000Z

    Cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS) thin-film photovoltaic (PV) modules can exhibit substantial variation in measured performance depending on prior exposure history. This study examines the metastable performance changes in these PV modules with the goal of establishing standard preconditioning or stabilization exposure procedures to mitigate measured variations prior to current-voltage (IV) measurements.

  11. 2010 Minerals Yearbook U.S. Department of the Interior

    E-Print Network [OSTI]

    in 2010. A number of smaller companies produced specialty indium alloys and other indium products (t) of indium. The company has owned the property since 2005 (Lithic Resources Ltd., 2010). Indium and sputtering takes place. Indium can also be recovered from copper-indium-gallium- diselenide (CIGS) solar

  12. Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics

    E-Print Network [OSTI]

    Eisenberg, DA; Yu, M; Lam, CW; Ogunseitan, OA; Schoenung, JM

    2013-01-01T23:59:59.000Z

    aspects of ?exible CIGS solar cells and modules, Sol. Energycell technologies [2,3]. CIGS solar cells are comprised oflayers are used in CIGS solar cells, as illustrated in Table

  13. Manufacturing-Friendly Advance Seen in CIGS Solar Cell Processing (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-05-01T23:59:59.000Z

    Scientists developed a robust, high-performance amorphous InZnO transparent contact for CIGS solar cells.

  14. CIGS Solar Cell on Flexible Stainless Steel Substrate Fabricated by Sputtering Method: Simulation and Experimental Results

    E-Print Network [OSTI]

    Kanicki, Jerzy

    CIGS Solar Cell on Flexible Stainless Steel Substrate Fabricated by Sputtering Method: Simulation-electronic properties of the Cu(InGa)Se2(CIGS) solar cell fabricated by sputtering method on stainless steel substrate are consistent with each other. 1. Introduction Flexible Cu In Ga Se (CIGS) solar cells are very attractive

  15. Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and

    E-Print Network [OSTI]

    Sites, James R.

    Thesis Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and Explanation our supervision by Markus Gloeckler entitled "Numerical Modeling of CIGS Solar Cells: Definition. A three-layer structure, simulating a Cu(InGa)Se2 (CIGS) heterojunction solar cell, was set up using

  16. DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE Submitted by Pamela K ENTITLED THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE BE ACCEPTED AS FULFILLING IN PART RE OF DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE The relationship between basic solar-cell

  17. Measuring sheet resistance of CIGS solar cell's window layer by spatially resolved electroluminescence imaging

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1/12 Measuring sheet resistance of CIGS solar cell's window layer by spatially resolved model to simulate the behavior of CIGS solar cells based on the spread sheet resistance effect on the determination of the window layer sheet resistance in CIGS solar cells, but our approach could be transferred

  18. Characterization and Analysis of CIGS and CdTE Solar Cells: December 2004 - July 2008

    SciTech Connect (OSTI)

    Sites, J. R.

    2009-01-01T23:59:59.000Z

    The work reported here embodies a device-physics approach based on careful measurement and interpretation of data from CIGS and CdTe solar cells.

  19. Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics

    E-Print Network [OSTI]

    Eisenberg, DA; Yu, M; Lam, CW; Ogunseitan, OA; Schoenung, JM

    2013-01-01T23:59:59.000Z

    3 is the solar panel with the lowest-hazard CIGS solar cellde (CIGS) solar cells (found within solar panels) of greatersolar cell material compositions found within solar panels.

  20. 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

  1. CIG The Role of the Academic Mentor Page 1 Academic Mentoring Program

    E-Print Network [OSTI]

    Kaessmann, Henrik

    CIG ­ The Role of the Academic Mentor Page 1 Academic Mentoring Program The Role of an Academic Mentor The Center for Integrative Genomics (CIG) at the University of Lausanne (UNIL) offers an academic mentoring program to its PhD students. The academic mentoring program is one arm of a two-tier mentoring

  2. TOWARDS CIGS SOLAR CELLS WITH REDUCED FILM THICKNESS: A STUDY OF OPTICAL PROPERTIES AND OF PHOTONIC STRUCTURES FOR LIGHT TRAPPING

    E-Print Network [OSTI]

    TOWARDS CIGS SOLAR CELLS WITH REDUCED FILM THICKNESS: A STUDY OF OPTICAL PROPERTIES AND OF PHOTONIC ABSTRACT: In view of large-scale exploitation of CuIn1-xGaxSe2 (CIGS) solar cells for photovoltaic energy. In this work we perform a full study of optical properties of CIGS solar cells grown by a hybrid sputtering

  3. 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

  4. Explanation of Light/Dark Superposition Failure in CIGS Solar Cells Markus Gloeckler, Caroline R. Jenkins, and James R. Sites

    E-Print Network [OSTI]

    Sites, James R.

    Explanation of Light/Dark Superposition Failure in CIGS Solar Cells Markus Gloeckler, Caroline R ABSTRACT CIGS solar cells in many cases show a failure of light/dark superposition of their current feature in CuIn1-xGaxSe2 (CIGS) solar cells is the lack of superposition between light and dark current

  5. Electrospun Gallium Nitride Nanofibers

    SciTech Connect (OSTI)

    Melendez, Anamaris; Morales, Kristle; Ramos, Idalia [University of Puerto Rico at Humacao, Humacao (Puerto Rico); Campo, Eva [Centre Nacional de Microelectronica, Barcelona (Spain); Santiago, Jorge J. [University of Pennsylvania, Philadelphia (United States)

    2009-04-19T23:59:59.000Z

    The high thermal conductivity and wide bandgap of gallium nitride (GaN) are desirable characteristics in optoelectronics and sensing applications. In comparison to thin films and powders, in the nanofiber morphology the sensitivity of GaN is expected to increase as the exposed area (proportional to the length) increases. In this work we present electrospinning as a novel technique in the fabrication of GaN nanofibers. Electrospinning, invented in the 1930s, is a simple, inexpensive, and rapid technique to produce microscopically long ultrafine fibers. GaN nanofibers are produced using gallium nitrate and dimethyl-acetamide as precursors. After electrospinning, thermal decomposition under an inert atmosphere is used to pyrolyze the polymer. To complete the preparation, the nanofibers are sintered in a tube furnace under a NH{sub 3} flow. Both scanning electron microscopy and profilometry show that the process produces continuous and uniform fibers with diameters ranging from 20 to a few hundred nanometers, and lengths of up to a few centimeters. X-ray diffraction (XRD) analysis shows the development of GaN nanofibers with hexagonal wurtzite structure. Future work includes additional characterization using transmission electron microscopy and XRD to understand the role of precursors and nitridation in nanofiber synthesis, and the use of single nanofibers for the construction of optical and gas sensing devices.

  6. Gallium Safety in the Laboratory

    SciTech Connect (OSTI)

    Cadwallader, L.C.

    2003-05-07T23:59:59.000Z

    A university laboratory experiment for the US Department of Energy magnetic fusion research program required a simulant for liquid lithium. The simulant choices were narrowed to liquid gallium and galinstan (Ga-In-Sn) alloy. Safety information on liquid gallium and galinstan were compiled, and the choice was made to use galinstan. A laboratory safety walkthrough was performed in the fall of 2002 to support the galinstan experiment. The experiment has been operating successfully since early 2002.

  7. Formation of selenide, sulfide or mixed selenide-sulfide films on metal or metal coated substrates

    DOE Patents [OSTI]

    Eser, Erten; Fields, Shannon

    2012-05-01T23:59:59.000Z

    A process and composition for preventing cracking in composite structures comprising a metal coated substrate and a selenide, sulfide or mixed selenide sulfide film. Specifically, cracking is prevented in the coating of molybdenum coated substrates upon which a copper, indium-gallium diselenide (CIGS) film is deposited. Cracking is inhibited by adding a Se passivating amount of oxygen to the Mo and limiting the amount of Se deposited on the Mo coating.

  8. Modeling and simulation of CuIn{sub 1?x}Ga{sub x}Se{sub 2} based thin film solar cell

    SciTech Connect (OSTI)

    Kumari, S., E-mail: sarita.kumari132@gmail.com; Verma, A. S. [Department of Physics, Banasthali University, Rajasthan-304022 (India); Singh, P.; Gautam, R. [Department of Electronics and Communication, Krishna Institute of Engg. and Tech., Ghaziabad-201206 (India)

    2014-04-24T23:59:59.000Z

    In this work, CIGS (Copper Indium Gallium Diselenide) based solar cell structure has been simulated. We have been calculated short circuit current, open circuit voltage and efficiency of the cell. The thickness of the absorption layer is varied from 400 to 3000 nm, keeping the thickness of other layers unchanged. The effect of absorption layer thickness over cell performance has been analyzed and found that the efficiency increases upto 22% until the thickness of the absorption layer reaches around 2000 nm.

  9. Potential effects of gallium on cladding materials

    SciTech Connect (OSTI)

    Wilson, D.F.; Beahm, E.C.; Besmann, T.M.; DeVan, J.H.; DiStefano, J.R.; Gat, U.; Greene, S.R.; Rittenhouse, P.L.; Worley, B.A.

    1997-10-01T23:59:59.000Z

    This paper identifies and examines issues concerning the incorporation of gallium in weapons derived plutonium in light water reactor (LWR) MOX fuels. Particular attention is given to the more likely effects of the gallium on the behavior of the cladding material. The chemistry of weapons grade (WG) MOX, including possible consequences of gallium within plutonium agglomerates, was assessed. Based on the calculated oxidation potentials of MOX fuel, the effect that gallium may have on reactions involving fission products and possible impact on cladding performance were postulated. Gallium transport mechanisms are discussed. With an understanding of oxidation potentials and assumptions of mechanisms for gallium transport, possible effects of gallium on corrosion of cladding were evaluated. Potential and unresolved issues and suggested research and development (R and D) required to provide missing information are presented.

  10. Cost and Reliability Improvement for CIGS-Based PV on Flexible Substrate, Phase II: 26 September 2007 - 25 September 2008

    SciTech Connect (OSTI)

    Wiedeman, S.

    2009-03-01T23:59:59.000Z

    Global Solar's CIGS manufacturing cost has decreased by increased automation, higher materials utilization, and greater capacity with higher rates in all tools.

  11. Analysis of Alternate Methods to Obtain Stabilized Power Performance of CdTe and CIGS PV Modules (Presentation)

    SciTech Connect (OSTI)

    del Cueto, J. A.; Deline, C. A.; Rummel, S.

    2011-02-01T23:59:59.000Z

    This presentation outlines an analysis of alternate methods to obtain stabilized power performance of CdTe and CIGS PV modules.

  12. H I ASYMMETRIES IN THE ISOLATED GALAXY CIG 292

    SciTech Connect (OSTI)

    Portas, Antonio; Scott, Tom C.; Verdes-Montenegro, Lourdes; Sulentic, Jack; Sengupta, Chandreyee [Instituto de Astrofisica de Andalucia (CSIC), Glorieta de AstronomIa s/n, 18008 Granada (Spain); Brinks, Elias; Heesen, Volker [Centre for Astrophysics, University of Hertfordshire, Hatfield, Herts AL10 9AB (United Kingdom); Bosma, Albert; Athanassoula, E. [Laboratoire d'Astrophysique de Marseille (LAM), UMR6110, CNRS/Universite de Provence/CNRS, Technopole de Marseille Etoile, 38 rue Frederic Joliot Curie, 13388 Marseille CEDEX 13 (France); Espada, Daniel [National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Verley, Simon [Departamento de Fisica Teorica y del Cosmos, Facultad de Ciencias, Universidad de Granada (Spain); Yun, Min [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States)

    2011-09-20T23:59:59.000Z

    We present Expanded Very Large Array (EVLA) D-array observations of the 21 cm line of neutral hydrogen (H I) of CIG 292, an isolated SA(s)b galaxy at a distance of {approx}24.3 Mpc. From previous H I single dish observations the galaxy was known to have a mildly asymmetric H I profile (A {sub flux} = 1.23 {+-} 0.3). Our EVLA observations show there is {approx}12% more H I projected south of the optical center (approaching velocities) than in the north (receding velocities), despite the H I extending {approx}16% further to the north than the south. The H I projected within the optical disk must have been perturbed within the H I relaxation time ({approx}10{sup 8} yr) which implies that this cannot have been caused by any of the three nearest companions, as their distance ({approx}0.5 Mpc) is too large. Neither H I-rich companions nor tidal tails were found within our field of view and velocity range covered. Our kinematical data suggest that the inner part harbors an oval distortion whereas the outer regions show signs of a modest warp. The mild asymmetry in the H I global profile thus actually masks stronger asymmetries in the two-dimensional distributions of gas and star-forming regions in this galaxy. Since the galaxy is isolated, this must predominantly be due to processes related to its formation and secular evolution.

  13. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, Michael (Berkeley, CA); Newman, Nathan (Montara, CA); Fu, Tracy (Berkeley, CA); Ross, Jennifer (Pleasanton, CA); Chan, James (Berkeley, CA)

    1997-01-01T23:59:59.000Z

    Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5.times.10.sup.11 /cm.sup.3 and hole mobilities of about 500 cm.sup.2 /V-sec, measured at 250.degree. K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al.

  14. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, M.; Newman, N.; Fu, T.; Ross, J.; Chan, J.

    1997-08-12T23:59:59.000Z

    Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5{times}10{sup 11} /cm{sup 3} and hole mobilities of about 500 cm{sup 2} /V-sec, measured at 250 K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al. 9 figs.

  15. Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

    SciTech Connect (OSTI)

    Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.

    2012-10-01T23:59:59.000Z

    We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.

  16. Local environment and composition of magnesium gallium layered...

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

    environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR Local environment and composition of magnesium gallium...

  17. In-depth analysis of CIGS film for solar cells, structural and optical characterization

    E-Print Network [OSTI]

    Slobodskyy, A; ~Ulyanenkova, T; ~Doyle, S; Powalla, M; ~Baumbach, T; ~Lemmer, U

    2010-01-01T23:59:59.000Z

    Space-resolved X-ray diffraction measurements performed on gradient-etched CuIn$_{1-x}$Ga$_x$Se$_2$ (CIGS) solar cells provide information about stress and texture depth profiles in the absorber layer. An important parameter for CIGS layer growth dynamics, the absorber thickness-dependent stress in the molybdenum back contact is analyzed. Texturing of grains and quality of the polycrystalline absorber layer are correlated with the intentional composition gradients (band gap grading). Band gap gradient is determined by space-resolved photoluminescence measurements and correlated with composition and strain profiles.

  18. Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics

    E-Print Network [OSTI]

    Eisenberg, DA; Yu, M; Lam, CW; Ogunseitan, OA; Schoenung, JM

    2013-01-01T23:59:59.000Z

    Ga)(S,Se) 2 based thin ?lm photovoltaics: present status andcycle of CIGS thin ?lm photovoltaics Daniel A. Eisenberg a ,selenium–sul?de Thin ?lm photovoltaics Life cycle thinking a

  19. Recovery of gallium from aluminum industry residues

    SciTech Connect (OSTI)

    Carvalho, M.S.; Neto, K.C.M.; Nobrega, A.W.; Medeiros, J.A.

    2000-01-01T23:59:59.000Z

    A procedure is proposed to recover gallium from flue dust aluminum residues produced in plants by using solid-phase extraction with a commercial polyether-type polyurethane foam (PUF). Gallium can be separated from high concentrations of aluminum, iron, nickel, titanium, vanadium, copper, zinc, sulfate, fluoride, and chloride by extraction with PUF from 3 M sulfuric acid and 3 M sodium chloride concentration medium with at least a 92% efficiency. Gallium backextraction was fast and quantitative with ethanol solution. In all recovery steps commercial-grade reagents could be used, including tap water. The recovered gallium was precipitated with sodium hydroxide solution, purified by dissolution and precipitation, calcinated, and the final oxide was 98.6% pure.

  20. Developing Market Opportunities for Flexible Rooftop Applications of PV Using Flexible CIGS Technology: Market Considerations

    SciTech Connect (OSTI)

    Sabnani, L.; Skumanich, A.; Ryabova, E.; Noufi, R.

    2011-01-01T23:59:59.000Z

    There has been a recent upsurge in developments for building-integrated phototovoltaics (BiPV) roof top materials based on CIGS. Several new companies have increased their presence and are looking to bring products to market for this application in 2011. For roof-top application, there are significant key requirements beyond just having good conversion efficiency. Other attributes include lightweight, as well as moisture-proof, and fully functionally reliable. The companies bringing these new BIPV/BAPV products need to ensure functionality with a rigorous series of tests, and have an extensive set of 'torture' tests to validate the capability. There is a convergence of form, aesthetics, and physics to ensure that the CIGS BiPV deliver on their promises. This article will cover the developments in this segment of the BiPV market and delve into the specific tests and measurements needed to characterize the products. The potential market sizes are evaluated and the technical considerations developed.

  1. 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 of CIGS (Cu(In,Ga)Se2) based solar cells (20.8% efficiency) makes them promising candidate photovoltaic

  2. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2009. One company in Utah

    E-Print Network [OSTI]

    58 GALLIUM (Data in kilograms of gallium content unless otherwise noted) Domestic Production 98% of domestic gallium consumption. About 67% of the gallium consumed was used in integrated and Use: No domestic primary gallium recovery was reported in 2009. One company in Utah recovered

  3. Au-free Ohmic Contacts to Gallium Nitride and Graphene 

    E-Print Network [OSTI]

    Ravikirthi, Pradhyumna

    2014-08-10T23:59:59.000Z

    This work deals with Au-free contact metallization schemes for gallium nitride (GaN) and graphene semiconductors. Graphene and gallium nitride are promising materials that can potentially be integrated together in the near future for high frequency...

  4. Au-free Ohmic Contacts to Gallium Nitride and Graphene

    E-Print Network [OSTI]

    Ravikirthi, Pradhyumna

    2014-08-10T23:59:59.000Z

    This work deals with Au-free contact metallization schemes for gallium nitride (GaN) and graphene semiconductors. Graphene and gallium nitride are promising materials that can potentially be integrated together in the near future for high frequency...

  5. Effect of Gallium Nitride Template Layer Strain on the Growth...

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

    Gallium Nitride Template Layer Strain on the Growth of InxGa1-xNGaN Multiple Quantum Well Light Emitting Diodes. Effect of Gallium Nitride Template Layer Strain on the Growth of...

  6. Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films

    E-Print Network [OSTI]

    Tao, Jonathan Huai-Tse

    2010-01-01T23:59:59.000Z

    Gallium Nitride Doped With Europium," J. Appl. Phys. , 95Electroluminescence of Europium-doped Gallium Oxide ThinLuminescence Properties of Europium– terbium Double

  7. Thin Film CIGS and CdTe Photovoltaic Technologies: Commercialization, Critical Issues, and Applications; Preprint

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in theTheoreticalEnergy InnovationThin Film CIGS and

  8. ZnMgO by APCVD Enabling High-Performance Mid-bandgap CIGS on Polyimide Modules: October 2009--October 2010

    SciTech Connect (OSTI)

    Woods, L.

    2011-04-01T23:59:59.000Z

    This Pre-Incubator project was designed to increase the 'real world' CIGS based photovoltaic module performance and decrease the Levelized Cost of Energy (LCOE) of systems utilizing those modules compared to our traditional CIGS based photovoltaic modules. This was enabled by a) increasing the CIGS bandgap and b) developing better matched device finishing layers to the mid-bandgap CIGS based photovoltaics; including window and buffer layers (and eventually the TCO). Incremental progress in the novel device performance was demonstrated throughout the program, and ultimately achieved performance results that exceeded the milestones ahead of schedule. Metal-oxide buffer layer devices with mid-bandgap CIGS alloys on polyimide substrates were produced with efficiencies of over 12%. Corresponding mid-bandgap devices with CdS buffers produced over 13% efficient devices. Furthermore, no obvious degradation in the device performance has been observed to date, after proper storage ambient of the different types of unencapsulated devices were identified.

  9. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, John C. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    An all-ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorous co-implantation, in selected III-V semiconductor materials.

  10. Pulmonary gallium-67 uptake in amiodarone pneumonitis

    SciTech Connect (OSTI)

    van Rooij, W.J.; van der Meer, S.C.; van Royen, E.A.; van Zandwijk, N.; Darmanata, J.I.

    1984-02-01T23:59:59.000Z

    Three patients are presented suffering from interstitial pneumonitis caused by amiodarone. Pulmonary Ga-67 uptake occurred in all three. There appeared to be a discrepancy between the scintigraphic and radiographic findings in two patients. Gallium-67 lung scintigraphy may offer an early, sensitive indicator for amiodarone pneumonitis.

  11. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, J.C.; Shul, R.J.

    1999-02-02T23:59:59.000Z

    An ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same are disclosed. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorus co-implantation, in selected III-V semiconductor materials. 19 figs.

  12. 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 and Photovoltaics Swiss Federal Laboratories for Material Science and Technology Key issues in high efficiency CIGSTe Laboratory for Thin Films and Photovoltaics Empa- Swiss Federal Laboratories for Material Science

  13. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2005. One company in Utah

    E-Print Network [OSTI]

    66 GALLIUM (Data in kilograms of gallium content unless otherwise noted) Domestic Production, [(703) 648-7719, dkramer@usgs.gov, fax: (703) 648-7975] #12;67 GALLIUM Consolidation of companies and Use: No domestic primary gallium recovery was reported in 2005. One company in Utah recovered

  14. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1998. Two companies in

    E-Print Network [OSTI]

    66 GALLIUM (Data in kilograms of gallium content, unless otherwise noted) Domestic Production A. Kramer [(703) 648-7719, dkramer@usgs.gov, fax: (703) 648-7722] #12;67 GALLIUM Events, Trends and Use: No domestic primary gallium recovery was reported in 1998. Two companies in Oklahoma and Utah

  15. CIGS P1, P2, P3 Scribing Processes using a Pulse Programmable Industrial Fiber Laser: Preprint

    SciTech Connect (OSTI)

    Rekow, M.; Murison, R.; Panarello, T.; Dunsky, C.; Dinkel, C.; Nikumb, S.; Pern, F. J.; Mansfield, L.

    2010-10-01T23:59:59.000Z

    We describe a novel set of laser processes for the CIGS P1, P2 and P3 scribing steps, the development of which has been enabled by a unique pulse-programmable fiber laser. We find that the unique pulse control properties of this 1064 nm wavelength laser have significant effects on the material removal dynamics of the various film layers in the CIGS material system. In the case of the P2 and P3 processes, the shaped pulses create new laser/material interaction effects that permit the material to be cleanly and precisely removed with zero Heat Affected Zone (HAZ) at the edges of the scribe. The new P2 and P3 processes we describe demonstrate the first use of infrared nanosecond laser pulses that eliminate the HAZ and the consequent localized compositional changes in the CIGS absorber material that result in poor shunt resistance. SEM micrographs and EDX compositional scans are presented. For the P1 scribe, we process the bi-layer molybdenum from the film side as well as through the glass substrate. Microscopic inspection and compositional analysis of the scribe lines are not sufficient to determine electrical and optical performance in working PV modules. Therefore, to demonstrate the applicability of the infrared pulse-programmable laser to all three scribing processes for thin-film CIGS, we fabricate small-size multiple-cell monolithically interconnected mini-modules in partnership with the National Renewable Energy Laboratory (Golden, Colorado). A total of four mini-modules are produced, two utilizing all laser scribing, and two with the P2 and P3 steps mechanically scribed (by a third party) for reference. Mini-module performance data measured at NREL is presented, and we also discuss the commercialization potential of the new single-laser CIGS scribing process. Finally we present a phenomenological model to describe this physics underlying this novel ablation process.

  16. Interactions of zircaloy cladding with gallium -- 1997 status

    SciTech Connect (OSTI)

    Wilson, D.F.; DiStefano, J.R.; King, J.F.; Manneschmidt, E.T.; Strizak, J.P.

    1997-11-01T23:59:59.000Z

    A four phase program has been implemented to evaluate the effect of gallium in mixed oxide (MOX) fuel derived from weapons grade (WG) plutonium on Zircaloy cladding performance. The objective is to demonstrate that low levels of gallium will not compromise the performance of the MOX fuel system in LWR. This graded, four phase experimental program will evaluate the performance of prototypic Zircaloy cladding materials against: (1) liquid gallium (Phase 1), (2) various concentrations of Ga{sub 2}O{sub 3} (Phase 2), (3) centrally heated surrogate fuel pellets with expected levels of gallium (Phase 3), and (4) centrally heated prototypic MOX fuel pellets (Phase 4). This status report describes the results of an initial series of tests for phases 1 and 2. Three types of tests are being performed: (1) corrosion, (2) liquid metal embrittlement (LME), and (3) corrosion mechanical. These tests are designed to determine the corrosion mechanisms, thresholds for temperature and concentration of gallium that may delineate behavioral regimes, and changes in mechanical properties of Zircaloy. Initial results have generally been favorable for the use of WG-MOX fuel. The MOX fuel cladding, Zircaloy, does react with gallium to form intermetallic compounds at {ge} 300 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (in parts per million) of gallium in the MOX fuel. While continued migration of gallium into the initially formed intermetallic compound results in large stresses that can lead to distortion, this is also highly unlikely because of the low mass of gallium or gallium oxide present and expected clad temperatures below 400 C. Furthermore, no evidence for grain boundary penetration by gallium has been observed.

  17. Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate...

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

    semipolar light-emitting diodes (LEDs) on low-defect bulk gallium nitride (GaN) substrates. Peak internal quantum efficiency (IQE) values of greater than 80% are...

  18. Photonuclear Reaction Cross Sections for Gallium Isotopes

    E-Print Network [OSTI]

    Serkan Akkoyun; Tuncay Bayram

    2014-09-08T23:59:59.000Z

    The photon induced reactions which are named as photonuclear reactions have a great importance in many field of nuclear, radiation physics and related fields. Since we have planned to perform photonuclear reaction on gallium target with bremmstrahlung photons from clinical linear accelerator in the future, the cross-sections of neutron (photo-neutron ({\\gamma},xn)) and proton (photo-proton ({\\gamma},xn)) productions after photon activation have been calculated by using TALYS 1.2 computer code in this study. The target nucleus has been considered gallium which has two stable isotopes, 69Ga and 71Ga. According to the results, we have seen that the calculations are in harmony in the limited literature values. Furthermore, the pre-equilibrium and compound process contributions to the total cross-section have been investigated.

  19. Gallium nanoparticles grow where light is

    E-Print Network [OSTI]

    K. F. MacDonald; W. S. Brocklesby; V. I. Emelyanov; V. A. Fedotov; S. Pochon; K. J. Ross; G. Stevens; N. I. Zheludev

    2001-05-15T23:59:59.000Z

    The study of metallic nanoparticles has a long tradition in linear and nonlinear optics [1], with current emphasis on the ultrafast dynamics, size, shape and collective effects in their optical response [2-6]. Nanoparticles also represent the ultimate confined geometry:high surface-to-volume ratios lead to local field enhancements and a range of dramatic modifications of the material's properties and phase diagram [7-9]. Confined gallium has become a subject of special interest as the light-induced structural phase transition recently observed in gallium films [10, 11] has allowed for the demonstration of all-optical switching devices that operate at low laser power [12]. Spontaneous self-assembly has been the main approach to the preparation of nanoparticles (for a review see 13). Here we report that light can dramatically influence the nanoparticle self-assembly process: illumination of a substrate exposed to a beam of gallium atoms results in the formation of nanoparticles with a relatively narrow size distribution. Very low light intensities, below the threshold for thermally-induced evaporation, exert considerable control over nanoparticle formation through non-thermal atomic desorption induced by electronic excitation.

  20. GALLIUM--2001 29.1 By Deborah A. Kramer

    E-Print Network [OSTI]

    the largest application for gallium, with optoelectronic devices [mostly laser diodes and light near the town of McDermitt in Humboldt County, NV. The company began initial drilling in October and announced preliminary results in November. According to the drilling results, gallium concentrations over

  1. Delta-phase manganese gallium on gallium nitride: a magnetically tunable spintronic system

    E-Print Network [OSTI]

    with Mn:Ga ratio between 1:1 to 1.5:1 is grown on wurtzite gallium nitride and scandium nitride substrates. Results suggest that for growth on wurtzite GaN, Ga-polar surface promotes quicker interface formation epitaxially on top of wide band-gap Ga-polar wurtzite GaN(0001), with controllable magnetism by adjusting

  2. Stability of CIGS Solar Cells and Component Materials Evaluated by a Step-Stress Accelerated Degradation Test Method: Preprint

    SciTech Connect (OSTI)

    Pern, F. J.; Noufi, R.

    2012-10-01T23:59:59.000Z

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15oC and then a 15% relative humidity (RH) increment step, beginning from 40oC/40%RH (T/RH = 40/40) to 85oC/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 ?m to 0.50 ?m on the cells. No clear 'stepwise' feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH < 55/55 and some showing large Voc, FF, and efficiency degradation due to increased series Rs (ohm-cm2) at T/RH ? 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and 'capacitor quality' factor (CPE-P), which were related to the cells? p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH ? 70/70. At T/RH = 85/70, substantial blistering of BZO layers on CIGS cell pieces was observed that was not seen on BZO/glass, and a CdS/CIGS sample displayed a small darkening and then flaking feature. Additionally, standard AlNi grid contact was less stable than thin Ni grid contact at T/RH ? 70/70. The edge sealant and moisture-blocking films were effective to block moisture ingress, as evidenced by the good stability of most CIGS solar cells and device components at T/RH = 85/70 for 704 h, and by preservation of the initial blue color on the RH indicator strips. The SSADT experiment is ongoing to be completed at T/RH = 85/85.

  3. Compatibility of ITER candidate structural materials with static gallium

    SciTech Connect (OSTI)

    Luebbers, P.R.; Michaud, W.F.; Chopra, O.K.

    1993-12-01T23:59:59.000Z

    Tests were conducted on the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor, e.g., Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, as well as Armco iron, Nickel 270, and pure chromium. Type 316 stainless steel is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400{degrees}C, corrosion rates are {approx}4.0, 0.5, and 0.03 mm/yr for type 316 SS, Inconel 625, and Nb-5 Mo- 1 Zr alloy, respectively. The pure metals react rapidly with gallium. In contrast to findings in earlier studies, pure iron shows greater corrosion than nickel. The corrosion rates at 400{degrees}C are {ge}88 and 18 mm/yr, respectively, for Armco iron and Nickel 270. The results indicate that at temperatures up to 400{degrees}C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The solubility data for pure metals and oxygen in gallium are reviewed. The physical, chemical, and radioactive properties of gallium are also presented. The supply and availability of gallium, as well as price predictions through the year 2020, are summarized.

  4. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1996. Two companies in

    E-Print Network [OSTI]

    on world production of primary gallium were unavailable because data on the output of the few producers62 GALLIUM (Data in kilograms of gallium content, unless otherwise noted) Domestic Production in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar

  5. Thermoelectric transport properties of polycrystalline titanium diselenide co-intercalated with nickel and titanium using spark plasma sintering

    SciTech Connect (OSTI)

    Holgate, T.C. [Department of Energy Storage and Conversion, Technical University of Denmark, Riso Campus, 4000 Roskilde (Denmark); Zhu, S.; Zhou, M. [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Bangarigadu-Sanasy, S.; Kleinke, H. [Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); He, J. [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Tritt, T.M., E-mail: ttritt@clemson.edu [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)

    2013-01-15T23:59:59.000Z

    Polycrystalline samples of nickel intercalated (0-5%) TiSe{sub 2} were attempted via solid-state reaction in evacuated quartz tubes followed by densification using a spark plasma sintering process. X-ray diffraction data indicated that mixed NiSe{sub 2} and TiSe{sub 2} phases were present after initial synthesis by solid-state reaction, but a pure TiSe{sub 2} phase was present after the spark plasma sintering. While EPMA data reveals the stoichiometry to be near 1:1.8 (Ti:Se) for all samples, comparisons of the measured bulk densities to the theoretical densities suggest that the off stoichiometry is a result of the co-intercalation of both Ni and Ti rather than Se vacancies. Due to the presence of excess Ti (0.085-0.130 per formula) in the van der Waals gap of all the samples, the sensitive electron-hole balance is offset by the additional Ti-3d electrons, leading to an increase in the thermopower (n-type) over pristine, stoichiometric TiSe{sub 2}. The effects of the co-intercalation of both Ni and Ti in TiSe{sub 2} on the structural, thermal, and electrical properties are discussed herein. - Graphical abstract: Co-intercalation of nickel and excess titanium into the van der Waals gap of TiSe{sub 2} via solid state synthesis followed by spark plasma sintering results in a systematic shift in the ratio of hole and electron carrier concentration, which is close to unity for pristine TiSe{sub 2}. This directly affects the electrical transport properties, and as the structural disorder induced by intercalation suppresses the lattice thermal conductivity, co-intercalation is an effective route to enhance the thermoelectric properties of transition metal diselenides. Highlights: Black-Right-Pointing-Pointer Single phase bulk Ni and Ti co-intercalated TiSe{sub 2} samples prepared by spark plasma sintering. Black-Right-Pointing-Pointer Density and X-ray diffraction suggest that the Ni and excess Ti are ordered in the Van der Waals gap. Black-Right-Pointing-Pointer Co-intercalation of Ni and Ti can be used to control electron-hole ratio and structural disorder.

  6. Reversible expansion of gallium-stabilized (delta)-plutonium

    SciTech Connect (OSTI)

    Wolfer, W G; Oudot, B; Baclet, N

    2006-02-27T23:59:59.000Z

    It is shown that the transient expansion of plutonium-gallium alloys observed both in the lattice parameter as well as in the dimension of a sample held at ambient temperature can be explained by assuming incipient precipitation of Pu{sub 3}Ga. However, this ordered {zeta}-phase is also subject to radiation-induced disordering. As a result, the gallium-stabilized {delta}-phase, being metastable at ambient temperature, is driven towards thermodynamic equilibrium by radiation-enhanced diffusion of gallium and at the same time reverted back to its metastable state by radiation-induced disordering. A steady state is reached in which only a modest fraction of the gallium present is arranged in ordered {zeta}-phase regions.

  7. arsenide gallium nitride: Topics by E-print Network

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

    Lundberga,*, J. Lua , A Abstract The diffusion of indium and gallium in polycrystalline thin film Cu(In,Ga)Se2 layers has been with a larger number of vacancies, that facilitates...

  8. PROPERTIES OF Cd and Zn PARTIAL ELECTROLYTE TREATED CIGS SOLAR CELLS K. Ramanathan, F.S. Hasoon, S. Smith, A. Mascarenhas, H. Al-Thani, J. Alleman, H.S. Ullal and J. Keane

    E-Print Network [OSTI]

    Sites, James R.

    PROPERTIES OF Cd and Zn PARTIAL ELECTROLYTE TREATED CIGS SOLAR CELLS K. Ramanathan, F.S. Hasoon, SS/CIGS interface has been treated as a "non- interacting," or abrupt junction. There are a few reports [3 changes such as those mentioned above have not been adequately treated in further analysis of the junction

  9. Inhalation developmental toxicology studies: Gallium arsenide in mice and rats

    SciTech Connect (OSTI)

    Mast, T.J.; Greenspan, B.J.; Dill, J.A.; Stoney, K.H.; Evanoff, J.J.; Rommereim, R.L.

    1990-12-01T23:59:59.000Z

    Gallium arsenide is a crystalline compound used extensively in the semiconductor industry. Workers preparing solar cells and gallium arsenide ingots and wafers are potentially at risk from the inhalation of gallium arsenide dust. The potential for gallium arsenide to cause developmental toxicity was assessed in Sprague- Dawley rats and CD-1 (Swiss) mice exposed to 0, 10, 37, or 75 mg/m{sup 3} gallium arsenide, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and {approx}30 positively mated rats or {approx}24 positively mated mice. Mice were exposed on 4--17 days of gestation (dg), and rats on 4--19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. Gallium and arsenic concentrations were determined in the maternal blood and uterine contents of the rats (3/group) at 7, 14, and 20 dg. 37 refs., 11 figs., 30 tabs.

  10. Examination of Na-Doped Mo Sputtering for CIGS Devices: Cooperative Research and Development Final Report, CRADA Number CRD-10-375

    SciTech Connect (OSTI)

    Repins, I.

    2012-01-01T23:59:59.000Z

    This work has investigated the use of Na doped Mo (MONA) sputtering targets for use in preparing CIGS devices. The Mo:Na material is doped to about 3% Na by weight, implying that a 40 nm layer on top of the standard Mo contact contains sufficient Na to dope a 2.5 ..mu..m CIGS film. The ability to control Na doping independent of both CIGS processing conditions and adhesion is an important gain for industry and research. Manufacturers gain a route to increased manufacturability and performance, while NREL researchers gain a tightened performance distribution of devices and increased process flexibility. Our immediate partner in this work, the Climax Molybdenum Technology Center, gains validation of their product.

  11. 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim5742 www.advmat.de

    E-Print Network [OSTI]

    -generation photo- voltaics, such as copper indium gallium selenide (CIGS)[5,6] and copper zinc tin sulfide (CZTS

  12. Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers

    E-Print Network [OSTI]

    Woodward, R I; Runcorn, T H; Hu, G; Torrisi, F; Kelleher, E J R; Hasan, T

    2015-01-01T23:59:59.000Z

    We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.

  13. Application of ultrasound in solvent extraction of nickel and gallium

    SciTech Connect (OSTI)

    Pesic, B.

    1996-07-01T23:59:59.000Z

    The effects of ultrasound on the rate of solvent extraction of nickel with Lix 65N and Lix 70, and gallium with Kelex 100 were investigated. These solvent extraction systems are noted by their sluggish nature. Low frequency (20 kHz) ultrasound increased the rates of extraction of nickel by factors of four to seven. The ultrasound had no effect on the final chemical equilibrium. Gallium extraction rates were enhanced with the use of ultrasound by as much as a factor of 15. Again, the ultrasound had no effect on extraction equilibrium. For both nickel and gallium, the enhanced rates were attributed to increased interfacial surface area associated with ultrasonically induced cavitation and microdroplet formation. The stability of the microdroplets permitted intermittent application of ultrasound with corresponding decreases in ultrasonic energy requirements. The lowest energy consumption was observed with short (0.25 to 5 s) bursts of high power (41 to 61 W) ultrasonic inputs. The study also provided insight into the factors that affect the complex extraction of gallium from sodium aluminate solutions. The rate controlling step was found to be the dehydration of the gallate ion, Ga(OH)4, and the first complex formation between gallium and Kelex 100. Sodium was found to enhance the extraction rate up to a point, beyond which increased concentration was detrimental. Increasing aluminum concentration was found to slow extraction rates. Modifiers and diluents were shown to markedly affect extraction rates even without ultrasound. Ketone modifiers, particularly 2-undecanone, when used with Kermac 470B or Escaid 200 diluents enhanced extraction rates of gallium to the point that the use of ultrasound provided no additional benefits. The positive effects of ketone modifiers for the solvent extraction of gallium had not been previously reported.

  14. STAR FORMATION IN THE EXTENDED GASEOUS DISK OF THE ISOLATED GALAXY CIG 96

    SciTech Connect (OSTI)

    Espada, D.; Sabater, J.; Verdes-Montenegro, L.; Sulentic, J. [Instituto de Astrofisica de AndalucIa, CSIC, Apdo. 3004, 18080 Granada (Spain); Munoz-Mateos, J. C.; Gil de Paz, A. [Departamento de Astrofisica y CC. de la Atmosfera, Universidad Complutense de Madrid, Avda. de la Complutense, s/n, E-28040 Madrid (Spain); Boissier, S.; Athanassoula, E.; Bosma, A. [Laboratoire d'Astrophysique de Marseille, OAMP, Universite Aix-Marseille and CNRS UMR 6110, 38 rue Frederic Joliot-Curie, 13388 Marseille Cedex 13 (France); Verley, S. [Dept. de Fisica Teorica y del Cosmos, Universidad de Granada, Granada (Spain); Leon, S. [Joint ALMA Observatory/ESO, Av. Alonso de Cordova 3107, Vitacura, Santiago (Chile); Yun, M., E-mail: daniel.espada@nao.ac.jp, E-mail: despada@cfa.harvard.edu [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2011-07-20T23:59:59.000Z

    We study the Kennicutt-Schmidt star formation law and efficiency in the gaseous disk of the isolated galaxy CIG 96 (NGC 864), with special emphasis on its unusually large atomic gas (H I) disk (r{sub Hmathsci}/r{sub 25} = 3.5, r{sub 25} = 1.'85). We present deep Galaxy Evolution Explorer near- and far-UV observations, used as a recent star formation tracer, and we compare them with new, high-resolution (16''or 1.6 kpc) Very Large Array H I observations. The UV and H I maps show good spatial correlation outside the inner 1', where the H I phase dominates over H{sub 2}. Star-forming regions in the extended gaseous disk are mainly located along the enhanced H I emission within two (relatively) symmetric, giant gaseous spiral arm-like features, which emulate an H I pseudo-ring at r {approx_equal} 3'. Inside this structure, two smaller gaseous spiral arms extend from the northeast and southwest of the optical disk and connect to the previously mentioned H I pseudo-ring. Interestingly, we find that the (atomic) Kennicutt-Schmidt power-law index systematically decreases with radius, from N {approx_equal} 3.0 {+-} 0.3 in the inner disk (0.'8-1.'7) to N = 1.6 {+-} 0.5 in the outskirts of the gaseous disk (3.'3-4.'2). Although the star formation efficiency (SFE), the star formation rate per unit of gas, decreases with radius where the H I component dominates as is common in galaxies, we find that there is a break of the correlation at r = 1.5r{sub 25}. At radii 1.5r{sub 25} < r < 3.5r{sub 25}, mostly within the H I pseudo-ring structure, regions exist whose SFE remains nearly constant, SFE {approx_equal} 10{sup -11} yr{sup -1}. We discuss possible mechanisms that might be triggering the star formation in the outskirts of this galaxy, and we suggest that the constant SFE for such large radii (r > 2r{sub 25}) and at such low surface densities might be a common characteristic in extended UV disk galaxies.

  15. Process for forming pure silver ohmic contacts to N- and P-type gallium arsenide materials

    DOE Patents [OSTI]

    Hogan, S.J.

    1983-03-13T23:59:59.000Z

    Disclosed is an improved process for manufacturing gallium arsenide semiconductor devices having as its components a n-type gallium arsenide substrate layer and a p-type gallium arsenide diffused layer. The improved process comprises forming a pure silver ohmic contact to both the diffuse layer and the substrate layer wherein the n-type layer comprises a substantially low doping carrier concentration.

  16. Proc. of the 24th IEEE Photovoltaic Specialists Conference (IEEE, New York, 1995), pp. 164-167. SODIUM DIFFUSION, SELENIZATION, AND MICROSTRUCTURAL EFFECTS

    E-Print Network [OSTI]

    Scofield, John H.

    to our usual solar cell processing stages, including the high-temperature deposition of CIS and CIGS by the "best" polycrystalline thin film copper indium diselenide (CIGS) based small-area solar cells has risen their implications for CIS and CIGS solar cell fabrication. AS-DEPOSITED FILMS Sample Fabrication Films were sputter

  17. Trajectory-Oriented and Fault-Tolerant-Based Intelligent Process Control for Flexible CIGS PV Module Manufacturing; Final Technical Report, 13 May 2002--30 May 2005

    SciTech Connect (OSTI)

    Simpson, L.; Britt, J.; Birkmire, R.; Vincent, T.

    2005-10-01T23:59:59.000Z

    ITN Energy Systems, Inc., and Global Solar Energy, Inc., assisted by NREL's PV Manufacturing R&D program, have continued to advance CIGS production technology by developing trajectory-oriented predictive/control models, fault-tolerance control, control platform development, in-situ sensors, and process improvements. Modeling activities included developing physics-based and empirical models for CIGS and sputter-deposition processing, implementing model-based control, and applying predictive models to the construction of new evaporation sources and for control. Model-based control is enabled by implementing reduced or empirical models into a control platform. Reliability improvement activities include implementing preventive maintenance schedules; detecting failed sensors/equipment and reconfiguring to tinue processing; and systematic development of fault prevention and reconfiguration strategies for the full range of CIGS PV production deposition processes. In-situ sensor development activities have resulted in improved control and indicated the potential for enhanced process status monitoring and control of the deposition processes. Substantial process improvements have been made, including significant improvement in CIGS uniformity, thickness control, efficiency, yield, and throughput. In large measure, these gains have been driven by process optimization, which in turn have been enabled by control and reliability improvements due to this PV Manufacturing R&D program.

  18. Interaction of a Liquid Gallium Jet with ISTTOK Edge Plasmas

    SciTech Connect (OSTI)

    Gomes, R. B.; Fernandes, H.; Silva, C.; Pereira, T.; Figueiredo, J.; Carvalho, B.; Soares, A.; Duarte, P.; Varandas, C. [Associacao EURATOM/IST, Centro de Fusao Nuclear, Av. Rovisco Pais, 1049-001 Lisboa, Porugal (Portugal); Sarakovskis, A.; Lielausis, O.; Klyukin, A.; Platacis, E.; Tale, I. [Association EURATOM/University of Latvia, Institute of Solid State Physics, 8 Kengaraga Str., LV-1063 Riga (Latvia)

    2008-04-07T23:59:59.000Z

    The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages in the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaust from fusion devices. Presently the most promising candidate materials are lithium and gallium. However, lithium has a short liquid state range when compared, for example, with gallium that has essentially better thermal properties and lower vapor pressure. To explore further these properties, ISTTOK tokamak is being used to test the interaction of a free flying, fully formed liquid gallium jet with the plasma. The interacting, 2.3 mm diameter, jet is generated by hydrostatic pressure and has a 2.5 m/s flow velocity. The liquid metal injector has been build to allow the positioning of the jet inside the tokamak chamber, within a 13 mm range. This paper presents the first obtained experimental results concerning the liquid gallium jet-plasma interaction. A stable jet has been obtained, which was not noticeably affected by the magnetic field transients. ISTTOK has been successfully operated with the gallium jet without degradation of the discharge or a significant plasma contamination by liquid metal. This observation is supported by spectroscopic measurements showing that gallium radiation is limited to the region around the jet. Furthermore, the power deposited on the jet has been evaluated at different radial locations and the surface temperature increase estimated.

  19. Pair distribution function study on compression of liquid gallium

    SciTech Connect (OSTI)

    Luo, Shengnian [Los Alamos National Laboratory; Yu, Tony [SUNY-SB; Chen, Jiuhua [SUNY-SB; Ehm, Lars [SUNY-SB; Guo, Quanzhong [SUNY-SB; Parise, John [SUNY-SB

    2008-01-01T23:59:59.000Z

    Integrating a hydrothermal diamond anvil cell (HDAC) and focused high energy x-ray beam from the superconductor wiggler X17 beamline at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL), we have successfully collected high quality total x-ray scattering data of liquid gallium. The experiments were conducted at a pressure range from 0.1GPa up to 2GPa at ambient temperature. For the first time, pair distribution functions (PDF) for liquid gallium at high pressure were derived up to 10 {angstrom}. Liquid gallium structure has been studied by x-ray absorption (Di Cicco & Filipponi, 1993; Wei et al., 2000; Comez et al., 2001), x-ray diffraction studies (Waseda & Suzuki, 1972), and molecular dynamics simulation (Tsay, 1993; Hui et al., 2002). These previous reports have focused on the 1st nearest neighbor structure, which tells us little about the atomic arrangement outside the first shell in non- crystalline materials. This study focuses on the structure of liquid gallium and the atomic structure change due to compression. The PDF results show that the observed atomic distance of the first nearest neighbor at 2.78 {angstrom} (first G(r) peak and its shoulder at the higher Q position) is consistent with previous studies by x-ray absorption (2.76 {angstrom}, Comez et al., 2001). We have also observed that the first nearest neighbor peak position did not change with pressure increasing, while the farther peaks positions in the intermediate distance range decreased with pressure increasing. This leads to a conclusion of the possible existence of 'locally rigid units' in the liquid. With the addition of reverse Monte Carlo modeling, we have observed that the coordination number in the local rigit unit increases with pressure. The bulk modulus of liquid gallium derived from the volume compression curve at ambient temperature (300K) is 12.1(6) GPa.

  20. Self- and zinc diffusion in gallium antimonide

    SciTech Connect (OSTI)

    Nicols, Samuel Piers

    2002-03-26T23:59:59.000Z

    The technological age has in large part been driven by the applications of semiconductors, and most notably by silicon. Our lives have been thoroughly changed by devices using the broad range of semiconductor technology developed over the past forty years. Much of the technological development has its foundation in research carried out on the different semiconductors whose properties can be exploited to make transistors, lasers, and many other devices. While the technological focus has largely been on silicon, many other semiconductor systems have applications in industry and offer formidable academic challenges. Diffusion studies belong to the most basic studies in semiconductors, important from both an application as well as research standpoint. Diffusion processes govern the junctions formed for device applications. As the device dimensions are decreased and the dopant concentrations increased, keeping pace with Moore's Law, a deeper understanding of diffusion is necessary to establish and maintain the sharp dopant profiles engineered for optimal device performance. From an academic viewpoint, diffusion in semiconductors allows for the study of point defects. Very few techniques exist which allow for the extraction of as much information of their properties. This study focuses on diffusion in the semiconductor gallium antimonide (GaSb). As will become clear, this compound semiconductor proves to be a powerful one for investigating both self- and foreign atom diffusion. While the results have direct applications for work on GaSb devices, the results should also be taken in the broader context of III-V semiconductors. Results here can be compared and contrasted to results in systems such as GaAs and even GaN, indicating trends within this common group of semiconductors. The results also have direct importance for ternary and quaternary semiconductor systems used in devices such as high speed InP/GaAsSb/InP double heterojunction bipolar transistors (DHBT) [Dvorak, (2001)]. Many of the findings which will be reported here were previously published in three journal articles. Hartmut Bracht was the lead author on two articles on self-diffusion studies in GaSb [Bracht, (2001), (2000)], while this report's author was the lead author on Zn diffusion results [Nicols, (2001)]. Much of the information contained herein can be found in those articles, but a more detailed treatment is presented here.

  1. (Data in kilograms of gallium content, unless noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1995. Two companies in

    E-Print Network [OSTI]

    : No domestic primary gallium recovery was reported in 1995. Two companies in Oklahoma and Utah recovered devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar cells contract to a consortium of private companies to develop gallium nitride technology. Blue LED's are useful

  2. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2002. Two companies in

    E-Print Network [OSTI]

    and Use: No domestic primary gallium recovery was reported in 2002. Two companies in Oklahoma and Utah diodes, photodetectors, and solar cells. Integrated circuits represented 65% of gallium demand forecasts of market growth, several companies were consolidating, reducing, or eliminating their Ga

  3. E-Print Network 3.0 - arsenide- gallium instrument Sample Search...

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

    Materials Science 5 Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride by metalorganic vapor-phase epitaxy Summary: Formation of etch pits...

  4. Nanosecond dynamics of a gallium mirror's light-induced reflectivity change

    E-Print Network [OSTI]

    V. Albanis; S. Dhanjal; V. I. Emelyanov; V. A. Fedotov; K. F. MacDonald; P. Petropoulos; D. J. Richardson; N. I. Zheludev

    2000-10-05T23:59:59.000Z

    Transient pump-probe optical reflectivity measurements of the nano/microsecond dynamics of a fully reversible, light-induced, surface-assisted metallization of gallium interfaced with silica are reported. The metallization leads to a considerable increase in the interface's reflectivity when solid a-gallium is on the verge of melting. The reflectivity change was found to be a cumulative effect that grows with light intensity and pulse duration. The reflectivity relaxes back to that of alpha-gallium when the excitation is withdrawn in a time that increases critically at gallium's melting point. The effect is attributed to a non-thermal light-induced structural phase transition.

  5. Indium-Gallium Segregation in CuIn$_{x}$Ga$_{1-x}$Se$_2$: An ab initio based Monte Carlo Study

    E-Print Network [OSTI]

    Ludwig, Christian D R; Felser, Claudia; Schilling, Tanja; Windeln, Johannes; Kratzer, Peter

    2010-01-01T23:59:59.000Z

    Thin-film solar cells with CuIn$_x$Ga$_{1-x}$Se$_2$ (CIGS) absorber are still far below their efficiency limit, although lab cells reach already 19.9%. One important aspect is the homogeneity of the alloy. Large-scale simulations combining Monte Carlo and density functional calculations show that two phases coexist in thermal equilibrium below room temperature. Only at higher temperatures, CIGS becomes more and more a homogeneous alloy. A larger degree of inhomogeneity for Ga-rich CIGS persists over a wide temperature range, which may contribute to the low observed efficiency of Ga-rich CIGS solar cells.

  6. FTIR and FT-PL Spectroscopic Analysis of TPV Materials and Devices

    SciTech Connect (OSTI)

    Webb, J. D.; Gedvilas, L. M.; Olson, M. R.; Wu, X.; Duda, A.; Wanlass, M. W.; Jones, K. M.

    1998-10-28T23:59:59.000Z

    Impurities in cadmium sulfide (CdS) films are a concern in the fabrication of copper (indium, gallium) diselenide (CIGS) and cadmium telluride (CdTe) photovoltaic devices. Devices incorporating chemical-bath-deposited (CBD) CdS are comparable in quality to devices incorporating purer CdS films grown using vacuum deposition techniques, despite the higher impurity concentrations typically observed in the CBD CdS films. In this paper, we summarize and review the results of Fourier transform infrared (FTIR), Auger, electron microprobe, and X-ray photoelectron spectroscopic (XPS) analyses of the impurities in CBD CdS films. We show that these impurities differ as a function of substrate type and film deposition conditions. We also show that some of these impurities exist as 102 micron-scale precipitates.

  7. Cost and Reliability Improvement for CIGS-Based PV on Flexible Substrate: May 24, 2006 -- July 31, 2010

    SciTech Connect (OSTI)

    Wiedeman, S.

    2011-05-01T23:59:59.000Z

    Global Solar Energy rapidly advances the cost and performance of commercial thin-film CIGS products using roll-to-roll processing on steel foil substrate in compact, low cost deposition equipment, with in-situ sensors for real-time intelligent process control. Substantial increases in power module efficiency, which now exceed 13%, are evident at GSE factories in two countries with a combined capacity greater than 75 MW. During 2009 the average efficiency of cell strings (3780 cm2) was increased from 7% to over 11%, with champion results exceeding 13% Continued testing of module reliability in rigid product has reaffirmed extended life expectancy for standard glass product, and has qualified additional lower-cost methods and materials. Expected lifetime for PV in flexible packages continues to increase as failure mechanisms are elucidated, and resolved by better methods and materials. Cost reduction has been achieved through better materials utilization, enhanced vendor and material qualification and selection. The largest cost gains have come as a result of higher cell conversion efficiency and yields, higher processing rates, greater automation and improved control in all process steps. These improvements are integral to this thin film PV partnership program, and all realized with the 'Gen2' manufacturing plants, processes and equipment.

  8. Synthesis and microstructure of gallium phosphide nanowires W. S. Shi, Y. F. Zheng, N. Wang,a)

    E-Print Network [OSTI]

    Zheng, Yufeng

    Synthesis and microstructure of gallium phosphide nanowires W. S. Shi, Y. F. Zheng, N. Wang,a) C. S May 2001 Gallium phosphide GaP nanowires of 22 nm in diameter and hundreds micrometers in length were synthesized by laser ablation of a powder mixture of GaP and gallium oxide (Ga2O3 . The morphology

  9. IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 2, APRIL 2012 123 Gallium Arsenide Solar Cell Absorption

    E-Print Network [OSTI]

    Grandidier, Jonathan

    IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 2, APRIL 2012 123 Gallium Arsenide Solar Cell Absorption--Gallium arsenide, nanospheres, photovoltaic systems, whispering gallery modes (WGMs). I. INTRODUCTION THE route as the active layer is thinned [2]. Thin-film photovoltaics offer the possibility to significantly reduce

  10. Two-photon photovoltaic effect in gallium arsenide Jeff Chiles,1

    E-Print Network [OSTI]

    Fathpour, Sasan

    Two-photon photovoltaic effect in gallium arsenide Jichi Ma,1 Jeff Chiles,1 Yagya D. Sharma,2 214669); published September 4, 2014 The two-photon photovoltaic effect is demonstrated in gallium; (230.0250) Optoelectronics; (040.5350) Photovoltaic; (130.4310) Nonlinear. http://dx.doi.org/10.1364/OL

  11. Synthesis and use of (polyfluoroaryl)fluoroanions of aluminum, gallium and indium

    DOE Patents [OSTI]

    Marks, Tobin J. (Evanston, IL); Chen, You-Xian (Midland, MI)

    2000-01-01T23:59:59.000Z

    Salts of (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are described. The (polyfluoroaryl)fluoroanions have the formula [ER'R"R'"F].sup..crclbar. wherein E is aluminum, gallium, or indium, wherein F is fluorine, and wherein R', R", and R'" is each a fluorinated phenyl, fluorinated biphenyl, or fluorinated polycyclic group.

  12. Gallium/aluminum nanocomposite material for nonlinear optics and nonlinear plasmonics

    E-Print Network [OSTI]

    Zheludev, Nikolay

    Gallium/aluminum nanocomposite material for nonlinear optics and nonlinear plasmonics A. V penetration of gallium into an aluminum film. These composite films form mirrorlike interfaces with silica optics and active plasmonics. The material is a polycrystalline aluminum film on a silica sub- strate

  13. EA-1686: Department of Energy Loan Guarantee to SoloPower Inc. for the Electrodeposition-based Copper indium gallium selenide (CIGS) Solar Technology Manufacturing Facility near San Jose, California

    Broader source: Energy.gov [DOE]

    EA cancelled due to a change in project scope; DOE prepared a categorical exclusion determination (8/15/11).

  14. Spectroscopy of vanadium (III) doped gallium lanthanum sulphide chalcogenide glass

    E-Print Network [OSTI]

    Hughes, M; Rutt, H; Hewak, D

    2014-01-01T23:59:59.000Z

    Vanadium doped gallium lanthanum sulphide glass (V:GLS) displays three absorption bands at 580, 730 and 1155 nm identified by photoluminescence excitation measurements. Broad photoluminescence, with a full width half maximum (FWHM) of 500 nm, is observed peaking at 1500 nm when exciting at 514, 808 and 1064 nm. The fluorescence lifetime and quantum efficiency at 300 K were measured to be 33.4 us and 4 % respectively. From the available spectroscopic data we propose the vanadium ions valence to be 3+ and be in tetrahedral coordination The results indicate potential for development of a laser or optical amplifier based on V:GLS.

  15. Fabrication of a gated gallium arsenide heterostructure resonant tunneling diode

    E-Print Network [OSTI]

    Kinard, William Brian

    1989-01-01T23:59:59.000Z

    , . ' 'CONTACT PAD' PLANAR I ZED POLYAM I DE RECTIFYI CONTACT N DBHS Pig. 2. f'utavvay vieiv of a gated gallium arsenide heterostructure resonant tunneling diode 1018 graded from 10 18 io" 10? (lightly doped) units=cm 8 ?graded from 10 to 18...FABRICATION OF A GATED GALLIL". tl ARSEXIDE HETEROSTRL CTL RF. RESONANT TF'XXELI'XG DIODE A Thesis bt ttrILLIAAI BRIA'. s KI'iARD Subnut ted to the Office of Graduate Studies of Texas AE;M Eniverstty tn partial fulfillment of the requirements...

  16. Layer-By-Layer Self-Assembly of CIGS Nanoparticles and Polymers for All-Solution Processable Low-Cost, High-Efficiency Solar Cells

    E-Print Network [OSTI]

    Zhou, Yaoqi

    -Cost, High-Efficiency Solar Cells Tung Ho1 , Robert Vittoe3 , Namratha Kakumanu2 , Sudhir Shrestha2-Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202 Thin film solar cells made from copper indium gallium thereby affecting solar cell efficiency. This research aims to study various polymer materials to replace

  17. Gallium phosphide high-temperature bipolar junction transistor

    SciTech Connect (OSTI)

    Zipperian, T.E.; Dawson, L.R.; Caffin, R.J.

    1981-03-01T23:59:59.000Z

    Preliminary results are reported on the development of a high-temperature (> 350/sup 0/C) gallium phosphide bipolar junction transistor (BJT) for goethermal and other energy applications. This four-layer p/sup +/n/sup -/pp/sup +/ structure was fromed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into the lightly doped base. By appropriate choice of electrodes, the device may also be driven as an n-channel junction field-effect transistor. The gallium phosphide BJT is observed to have a common-emitter current gain peaking in the range of 6 to 10 (for temperatures from 20/sup 0/C to 400/sup 0/C) and a room-temperature, punchthrough-limited, collector-emitter breakdown voltage of approximately -6V. Other parameters of interest include an f/sub/ = 400 KHz (at 20/sup 0/C) and a collector base leakage current = 200 ..mu..A (at 350/sup 0/C).

  18. Gallium nitride microcavities formed by photoenhanced wet oxidation

    SciTech Connect (OSTI)

    Peng, L.-H.; Lu, C.-Y.; Wu, W.-H.; Wang, S.-L. [Department of Electrical Engineering and Institute of Electro-Optical Engineering, National Taiwan University, Taipei, Taiwan (China)

    2005-10-17T23:59:59.000Z

    We report the formation of gallium nitride (GaN) microcavities by manipulating a photoenhanced oxidation rate difference between the polar and nonpolar crystallographic planes of GaN. When immersed in a buffered acetic (CH{sub 3}COOH) electrolyte of pH{approx}6.2 at room temperature, it is shown that the photo-oxidation can proceed at a rate that is one order of magnitude slower on the nonpolar plane of {l_brace}1100{r_brace}{sub GaN} than on the polar plane of {l_brace}0001{r_brace}{sub GaN} due to the reduced surface field action. Gallium nitride microcavities bounded by optically smooth {l_brace}1100{r_brace} and {l_brace}1103{r_brace} facets can thus be preferentially formed on the c-plane sapphire substrate after dissolving the oxide layer. The optical properties of these GaN hexagonal cavities reveal characteristic peaks of whispering gallery modes in resonance with the GaN band edge emission spectrum. A typical cavity Q factor of 10{sup 3} is observed in these GaN microcavities due to a reduced optical scattering loss in the wet chemical reaction process.

  19. Specific interaction of fluoride ions with aluminum and gallium solvates in an ethylene glycol solutions

    SciTech Connect (OSTI)

    Petrosyants, S.P.; Tsabel', E.R.; Buslaev, Yu.A.

    1986-01-01T23:59:59.000Z

    The interaction of aluminum chloride and gallium chloride with KF in ethylene glycol solutions with F:M/sup 3 +/ mole ratios approximately equal to 2 includes a step involving the formation of fluorine-containing species, in which the fluoride ions are held in the outer sphere of ethylene glycol solvates of aluminum and gallium. Complexes based on hexacoordinate solvates predominate in the solutions of aluminum, while in the case of gallium, in contrast to aluminum, the coexistence of tetra- and hexacoordinate complexes is characteristic. The configurational equilibrium in the solutions of gallium is one of the causes of the structurization of the solutions, i.e., polymerization due to the formation of H bonds between the fluoride ions and the coordinated ethylene glycol molecules.

  20. Luminescence dynamics and waveguide applications of europium doped gallium nitride powder

    E-Print Network [OSTI]

    Lipson, Michal

    Luminescence dynamics and waveguide applications of europium doped gallium nitride powder Carl B, bismuth shot, and europium ingot in an ammonia ambient to initially obtain chunks of the desired material

  1. First Results of the Testing of the Liquid Gallium Jet Limiter Concept for ISTTOK

    SciTech Connect (OSTI)

    Gomes, R. B.; Fernandes, H.; Silva, C.; Borba, D.; Carvalho, B.; Varandas, C. [Associacao EURATOM/IST, Centro de FuSao Nuclear, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Lielausis, O.; Klyukin, A.; Platacis, E.; Mikelsons, A.; Platnieks, I. [Association EURATOM/University of Latvia, Institute of Physics, 32 Miera Str., Salaspils, LV-2169 (Latvia)

    2006-12-04T23:59:59.000Z

    The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages to the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaustion from fusion devices. Presently the most promising materials are Lithium and Gallium. ISTTOK, a small size tokamak, will be used to test the behavior of a liquid Gallium jet in the vacuum chamber and its influence on the plasma. This paper presents a description of the conceived setup as well as experimental results. The liquid Gallium jet is generated by hydrostatic pressure and injected in a radial position close to a moveable stainless steel limiter. Both the jet and the limiter positions are variable allowing for a controlled exposure of the liquid Gallium to the edge plasma. The main components of the Gallium loop are a MHD pump, the liquid metal injector and a filtering system. The MHD pump is of the induction type, based on rotating permanent magnets. The injector is build from a stainless steel pipe ended by a shaping nozzle. A setup has been developed to introduce oxide-free Gallium inside the loop's main supply tank. Raw liquid metal is placed inside a chamber heated and degassed under high vacuum while clean Gallium is extracted from the main body of the liquefied metal. Prior to installation on the tokamak, the experimental rig has been implemented using a Pyrex tube as test chamber to investigate the stability of the Gallium jet and its break-up length for several nozzle sizes. Results are presented in this paper. This rig was also useful to assess the behavior of the overall implemented apparatus.

  2. High-Temperature Decomposition of Brønsted Acid Sites in Gallium-Substituted Zeolites

    SciTech Connect (OSTI)

    K Al-majnouni; N Hould; W Lonergan; D Vlachos; R Lobo

    2011-12-31T23:59:59.000Z

    The dehydroxylation of Broensted acid sites (BAS) in Ga-substituted zeolites was investigated at temperatures up to 850 C using X-ray absorption spectroscopy (XAS), Fourier transform infrared spectroscopy (FTIR), and mass spectrometry-temperature programmed desorption (MS-TPD). X-ray absorption near-edge spectroscopy (XANES) revealed that the majority of gallium has tetrahedral coordination even after complete dehydroxylation. The interatomic gallium-oxygen distance and gallium coordination number determined by extended X-ray absorption fine structure (EXAFS) are consistent with gallium in tetrahedral coordination at low T (< 550 C). Upon heating Ga-Beta and Ga-ZSM5 to 850 C, analysis of the EXAFS showed that 70 and 80% of the gallium was still in tetrahedral coordination. The remainder of the gallium was found to be in octahedral coordination. No trigonal Ga atoms were observed. FTIR measurements carried out at similar temperatures show that the intensity of the OH vibration due to BAS has been eliminated. MS-TPD revealed that hydrogen in addition to water evolved from the samples during dehydroxylation. This shows that dehydrogenation in addition to dehydration is a mechanism that contributes to BAS decomposition. Dehydrogenation was further confirmed by exposing the sample to hydrogen to regenerate some of the BAS as monitored by FTIR and MS-TPD.

  3. Study of liquid gallium at high pressure using synchrotron x-ray

    SciTech Connect (OSTI)

    Yu, Tony; Guo Quanzhong; Parise, John [Department of Geosciences, Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100 (United States); Chen Jiuhua [Department of Geosciences, Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100 (United States); Department of Mechanical and Materials Engineering, Center for the Study of Matters at Extreme Conditions, Florida International University, Miami, Florida 33199 (United States); Ehm, Lars [Department of Geosciences, Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100 (United States); National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States); Huang Shu [Department of Mechanical and Materials Engineering, Center for the Study of Matters at Extreme Conditions, Florida International University, Miami, Florida 33199 (United States); Luo Shengnian [Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2012-06-01T23:59:59.000Z

    Liquid gallium has been studied at high pressure up to 2 GPa and ambient temperature in a diamond anvil cell using high energy synchrotron x-ray beam. The total x-ray scattering data of liquid gallium were collected up to Q = 12 A{sup -1} and analyzed using pair distribution functions (PDF). The results indicate that the first nearest neighbor peak and second nearest neighbor (shoulder) peak of PDF in liquid gallium does not change with pressure, whereas the higher order (i.e., third and fourth) nearest neighbor peaks shift towards shorter distance with increasing pressure. Reverse Monte Carlo modeling based on the observed data shows that the coordination number in the liquid gallium increases with pressure from 10.5 at 0.3 GPa to 11.6 at 2 GPa. An atomic arrangement similar to the crystalline phase of Ga(II) with coordination number of 12 is proposed for the locally dense-packed rigid unit in liquid gallium. The volume compression data derived from the structure modeling yield a bulk modulus of 12.1(6) GPa for liquid gallium.

  4. Study of Magnetohydrodynamic Surface Waves on Liquid Gallium

    SciTech Connect (OSTI)

    Hantao Ji; William Fox; David Pace; H.L. Rappaport

    2004-05-13T23:59:59.000Z

    Magnetohydrodynamic (MHD) surface waves on liquid gallium are studied theoretically and experimentally in the small magnetic Reynolds number limit. A linear dispersion relation is derived when a horizontal magnetic field and a horizontal electric current is imposed. No wave damping is found in the shallow liquid limit while waves always damp in the deep liquid limit with a magnetic field parallel to the propagation direction. When the magnetic field is weak, waves are weakly damped and the real part of the dispersion is unaffected, while in the opposite limit waves are strongly damped with shortened wavelengths. In a table-top experiment, planar MHD surface waves on liquid gallium are studied in detail in the regime of weak magnetic field and deep liquid. A non-invasive diagnostic accurately measures surface waves at multiple locations by reflecting an array of lasers off the surface onto a screen, which is recorded by an Intensified-CCD camera. The measured dispersion relation is consistent with the linear theory with a reduced surface tension likely due to surface oxidation. In excellent agreement with linear theory, it is observed that surface waves are damped only when a horizontal magnetic field is imposed parallel to the propagation direction. No damping is observed under a perpendicular magnetic field. The existence of strong wave damping even without magnetic field suggests the importance of the surface oxide layer. Implications to the liquid metal wall concept in fusion reactors, especially on the wave damping and a Rayleigh-Taylor instability when the Lorentz force is used to support liquid metal layer against gravity, are discussed.

  5. By Deborah A. Kramer No primary gallium was produced in the United States in consumption were adjusted to reflect full industry coverage.

    E-Print Network [OSTI]

    that it would reopen its 50-ton-per-year gallium recovery facility in Pinjarra, Western Australia, in 1996

  6. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1997. Two companies in

    E-Print Network [OSTI]

    and Use: No domestic primary gallium recovery was reported in 1997. Two companies in Oklahoma and Utah in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar-than-expected increase in demand. The company planned to operate its refineries in France and Germany using stockpiled

  7. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1999. Two companies in

    E-Print Network [OSTI]

    and Use: No domestic primary gallium recovery was reported in 1999. Two companies in Oklahoma and Utah in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar in July. The additional facility was expected to double the company's refinery capacity to 100

  8. (Polyfluoroaryl) fluoroanions of aluminum, gallium, and indium of enhanced utility, uses thereof, and products based thereon

    DOE Patents [OSTI]

    Marks, Tobin J. (Evanston, IL); Chen, You-Xian (Midland, MI)

    2002-01-01T23:59:59.000Z

    The (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are novel weakly coordinating anions which are highly fluorinated. (Polyfluoroaryl)fluoroanions of one such type contain at least one ring substituent other than fluorine. These (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium have greater solubility in organic solvents, or have a coordinative ability essentially equal to or less than that of the corresponding (polyfluoroaryl)fluoroanion of aluminum, gallium, or indium in which the substituent is replaced by fluorine. Another type of new (polyfluoroaryl)fluoroanion of aluminum, gallium, and indium have 1-3 perfluorinated fused ring groups and 2-0 perfluorophenyl groups. When used as a cocatalyst in the formation of novel catalytic complexes with d- or f-block metal compounds having at least one leaving group such as a methyl group, these anions, because of their weak coordination to the metal center, do not interfere in the ethylene polymerization process, while affecting the propylene process favorably, if highly isotactic polypropylene is desired. Thus, the (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium of this invention are useful in various polymerization processes such as are described.

  9. (Polyfluoroaryl) fluoroanions of aluminum, gallium, and indium of enhanced utility, uses thereof, and products based thereon

    DOE Patents [OSTI]

    Marks, Tobin J. (Evanston, IL); Chen, You-Xian (Midland, MI)

    2001-01-01T23:59:59.000Z

    The (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are novel weakly coordinating anions which are highly fluorinated. (Polyfluoroaryl)fluoroanions of one such type contain at least one ring substituent other than fluorine. These (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium have greater solubility in organic solvents, or have a coordinative ability essentially equal to or less than that of the corresponding (polyfluoroaryl)fluoroanion of aluminum, gallium, or indium in which the substituent is replaced by fluorine. Another type of new (polyfluoroaryl)fluoroanion of aluminum, gallium, and indium have 1-3 perfluorinated fused ring groups and 2-0 perfluorophenyl groups. When used as a cocatalyst in the formation of novel catalytic complexes with d- or f-block metal compounds having at least one leaving group such as a methyl group, these anions, because of their weak coordination to the metal center, do not interfere in the ethylene polymerization process, while affecting the propylene process favorably, if highly isotactic polypropylene is desired. Thus, the (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium of this invention are useful in various polymerization processes such as are described.

  10. The design, construction, and testing of a nuclear fuel rod thermal simulation system to study gallium/Zircaloy interactions

    E-Print Network [OSTI]

    Allison, Christopher Curtis

    1999-01-01T23:59:59.000Z

    The presence of gallium in weapons grade plutonium has raised many questions concerning its use in light water reactor (LWR) fuel rods. The biggest concern is that the gallium will migrate down the thermal gradient in the fuel rod and deposit...

  11. Electron backscatter diffraction of plutonium-gallium alloys

    SciTech Connect (OSTI)

    Boehlert, C. J. (Carl J.); Zocco, T. G. (Thomas G.); Schulze, R. K. (Roland K.); Mitchell, J. N. (Jeremy N.); Pereyra, R. A. (Ramiro A.)

    2002-01-01T23:59:59.000Z

    At Los Alamos National Laboratory a recent experimental technique has been developed to characterize reactive metals, including plutonium arid cerium, using electron backscatter diffraction (EBSD). Microstructural characterization of plutonium and its alloys by EBSD had been previously elusive primarily because of the extreme toxicity and rapid surface oxidation rate associated with plutonium metal. The experimental techniques, which included ion-sputtering the metal surface using a scanning auger microprobe (SAM) followed by vacuum transfer of the sample from the SAM to the scanning electron microscope (SEM), used to obtain electron backscatter diffraction Kikuchi patterns (EBSPs) and orientation maps for plutonium-gallium alloys are described and the initial microstructural observations based on the analysis are discussed. Combining the SEM and EBSD observations, the phase transformation behavior between the {delta} and {var_epsilon} structures was explained. This demonstrated sample preparation and characterization technique is expected to be a powerful means to further understand phase transformation behavior, orientation relationships, and texlure in the complicated plutonium alloy systems.

  12. Crystal chemistry and self-lubricating properties of monochalcogenides gallium selenide and tin selenide

    SciTech Connect (OSTI)

    Erdemir, A.

    1993-02-01T23:59:59.000Z

    This paper describes the fundamentals of the crystal chemistry and self-lubricating mechanisms of two monochalcogenides; tin selenide and gallium selenide. Specifically, it enumerates their inter-atomic array and bond structure in crystalline states, and correlates this fundamental knowledge with their self-lubricating capacity. Friction tests assessing the self-lubricating performance of gallium and tin selenides were carried out on a pin-on-disk machine. Specifically, large crystalline pieces of gallium selenide and tin selenide were cut and cleaved into flat squares and subsequently rubbed against the sapphire balls. In another case, the fine powders (particle size {approx} 50--100 {mu}m) of gallium selenide and tin selenide were manually fed into the sliding interfaces of 440C pins and 440C disks. For the specific test conditions explored, it was found that the friction coefficients of the sapphire/gallium selenide and sapphire/tin selenide pairs were {approx} 0.23 and {approx} 0.35, respectively. The friction coefficients of 440C pin/440C disk test pairs with gallium selenide and tin selenide powders were on the orders of {approx} 0.22 and {approx} 0.38, respectively. For comparison, a number of parallel friction tests were performed with MoS{sub 2} powders and compacts and the results of these tests were also reported. The friction data together with the crystal-chemical knowledge and the electron microscopic evidence supported the conclusion that the lubricity and self-lubricating mechanisms of these solids are closely related to their crystal chemistry and the nature of interlayer bonding.

  13. Results of the Gallium-Clad Phase 3 and Phase 4 tasks (canceled prior to completion)

    SciTech Connect (OSTI)

    Morris, R.N.

    1998-08-01T23:59:59.000Z

    This report summarizes the results of the Gallium-Clad interactions Phase 3 and 4 tasks. Both tasks were to involve examining the out-of-pile stability of residual gallium in short fuel rods with an imposed thermal gradient. The thermal environment was to be created by an electrical heater in the center of the fuel rod and coolant flow on the rod outer cladding. Both tasks were canceled due to difficulties with fuel pellet fabrication, delays in the preparation of the test apparatus, and changes in the Fissile Materials Disposition program budget.

  14. Percolation of gallium dominates the electrical resistance of focused ion beam deposited metals

    SciTech Connect (OSTI)

    Faraby, H. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States); DiBattista, M. [Qualcomm Technologies Incorporated, San Diego, California 92121 (United States); Bandaru, P. R., E-mail: pbandaru@ucsd.edu [Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California 92093 (United States)

    2014-04-28T23:59:59.000Z

    Metal deposition through focused ion beam (FIB) based systems is thought to result in material composed of the primary metal from the metallo-organic precursor in addition to carbon, oxygen, and gallium. We determined, through electrical resistance and chemical composition measurements on a wide range of FIB deposited platinum and tungsten lines, that the gallium ion (Ga{sup +}) concentration in the metal lines plays the dominant role in controlling the electrical resistivity. Effective medium theory, based on McLachlan's formalisms, was used to describe the relationship between the Ga{sup +} concentration and the corresponding resistivity.

  15. In vitro bio-functionality of gallium nitride sensors for radiation biophysics

    SciTech Connect (OSTI)

    Hofstetter, Markus [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)] [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Howgate, John [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany)] [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany); Schmid, Martin [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)] [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Schoell, Sebastian; Sachsenhauser, Matthias [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany)] [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany); Adiguezel, Denis [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)] [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Stutzmann, Martin; Sharp, Ian D. [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany)] [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany); Thalhammer, Stefan, E-mail: stefan.thalhammer@helmholtz-muenchen.de [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)] [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)

    2012-07-27T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Gallium nitride based sensors show promising characteristics to monitor cellular parameters. Black-Right-Pointing-Pointer Cell growth experiments reveal excellent biocompatibiltiy of the host GaN material. Black-Right-Pointing-Pointer We present a biofunctionality assay using ionizing radiation. Black-Right-Pointing-Pointer DNA repair is utilized to evaluate material induced alterations in the cellular behavior. Black-Right-Pointing-Pointer GaN shows no bio-functional influence on the cellular environment. -- Abstract: There is an increasing interest in the integration of hybrid bio-semiconductor systems for the non-invasive evaluation of physiological parameters. High quality gallium nitride and its alloys show promising characteristics to monitor cellular parameters. Nevertheless, such applications not only request appropriate sensing capabilities but also the biocompatibility and especially the biofunctionality of materials. Here we show extensive biocompatibility studies of gallium nitride and, for the first time, a biofunctionality assay using ionizing radiation. Analytical sensor devices are used in medical settings, as well as for cell- and tissue engineering. Within these fields, semiconductor devices have increasingly been applied for online biosensing on a cellular and tissue level. Integration of advanced materials such as gallium nitride into these systems has the potential to increase the range of applicability for a multitude of test devices and greatly enhance sensitivity and functionality. However, for such applications it is necessary to optimize cell-surface interactions and to verify the biocompatibility of the semiconductor. In this work, we present studies of mouse fibroblast cell activity grown on gallium nitride surfaces after applying external noxa. Cell-semiconductor hybrids were irradiated with X-rays at air kerma doses up to 250 mGy and the DNA repair dynamics, cell proliferation, and cell growth dynamics of adherent cells were compared to control samples. The impact of ionizing radiation on DNA, along with the associated cellular repair mechanisms, is well characterized and serves as a reference tool for evaluation of substrate effects. The results indicate that gallium nitride does not require specific surface treatments to ensure biocompatibility and suggest that cell signaling is not affected by micro-environmental alterations arising from gallium nitride-cell interactions. The observation that gallium nitride provides no bio-functional influence on the cellular environment confirms that this material is well suited for future biosensing applications without the need for additional chemical surface modification.

  16. Millimeter wave ferromagnetic resonance in gallium-substituted ?-iron oxide

    SciTech Connect (OSTI)

    Chao, Liu, E-mail: liu.chao@tufts.edu; Afsar, Mohammed N. [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States); Ohkoshi, Shin-ichi [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2014-05-07T23:59:59.000Z

    In millimeter wave frequency range, hexagonal ferrites with high uniaxial anisotropic magnetic fields are used as absorbers. These ferrites include M-type barium ferrite (BaFe{sub 12}O{sub 19}) and strontium ferrite (SrFe{sub 12}O{sub 19}), which have natural ferromagnetic resonant frequency range from 40 GHz to 60?GHz. However, the higher frequency range lacks suitable materials that support the higher frequency ferromagnetic resonance. A new series of gallium-substituted ?-iron oxides (?-Ga{sub x}Fe{sub 2?x}O{sub 3}) are synthesized which have ferromagnetic resonant frequencies appearing over the frequency range 30 GHz–150 GHz. The ?-Ga{sub x}Fe{sub 2?x}O{sub 3} is synthesized by the combination of reverse micelle and sol-gel techniques or the sol-gel method only. The particle sizes are observed to be smaller than 100 nm. In this paper, the free space magneto-optical approach has been employed to study these newly developed ?-Ga{sub x}Fe{sub 2?x}O{sub 3} particles in millimeter waves. This technique enables to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the millimeter wave frequency range from a single set of direct measurements. The transmittance and absorbance spectra of ?-Ga{sub x}Fe{sub 2?x}O{sub 3} are shown in this paper. Strong ferromagnetic resonances at different frequencies determined by the x parameter are found.

  17. Gallium-cladding compatibility testing plan: Phase 3 -- Test plan for centrally heated surrogate rodlet test. Revision 2

    SciTech Connect (OSTI)

    Morris, R.N.; Baldwin, C.A.; Wilson, D.F.

    1998-07-01T23:59:59.000Z

    The Fissile Materials Disposition Program (FMDP) is investigating the use of weapons grade plutonium in mixed oxide (MOX) fuel for light-water reactors (LWR). Commercial MOX fuel has been successfully used in overseas reactors for many years; however, weapons derived fuel may differ from the previous commercial fuels because of small amounts of gallium impurities. A concern presently exists that the gallium may migrate out of the fuel, react with and weaken the clad, and thereby promote loss of fuel pin integrity. Phases 1 and 2 of the gallium task are presently underway to investigate the types of reactions that occur between gallium and clad materials. This is a Level-2 document as defined in the Fissile Materials Disposition Program Light-Water Reactor Mixed-Oxide Fuel Irradiation Test Project Plan. This Plan summarizes the projected Phase 3 Gallium-Cladding compatibility heating test and the follow-on post test examination (PTE). This work will be performed using centrally-heated surrogate pellets, to avoid unnecessary complexities and costs associated with working with plutonium and an irradiation environment. Two sets of rodlets containing pellets prepared by two different methods will be heated. Both sets will have an initial bulk gallium content of approximately 10 ppm. The major emphasis of the PTE task will be to examine the material interactions, particularly indications of gallium transport from the pellets to the clad.

  18. Development and modeling of iron-gallium alloys Rick Allen Kellogg

    E-Print Network [OSTI]

    Flatau, Alison B.

    Development and modeling of iron-gallium alloys by Rick Allen Kellogg A dissertation submitted APPENDIX C: POISSON'S RATIOS OF Fe-Al ALLOYS 154 REFERENCES 155 #12;iv ACKNOWLEDGEMENTS Many people deserve University and the Department of Aerospace Engineering and Engineering Mechanics for providing academic

  19. May 20, 2010 Growing gallium arsenide in thick multilayer stacks could make a big

    E-Print Network [OSTI]

    Rogers, John A.

    of photovoltaics and optoelectronic devices such as near-infrared (NIR) imagers looks set to become significantly material systems such as gallium nitride and indium phosphide (Nature 465 329). "We can generate compound of substrates, including glass and plastic. In photovoltaics, we expect the cost reductions to be significant

  20. Optical, electrical, and solar energy-conversion properties of gallium arsenide nanowire-array

    E-Print Network [OSTI]

    Zhou, Chongwu

    Optical, electrical, and solar energy-conversion properties of gallium arsenide nanowire, and will aid in the design and optimization of nanowire-based systems for solar energy-conversion applications, and the photoelectrochemical energy-conversion properties of GaAs nanowire arrays were evaluated in contact with one

  1. ELECTRON MICROPROBE AND PHOTOLUMINESCENCE ANALYSIS OF EUROPIUM-DOPED GALLIUM NITRIDE LIGHT EMITTERS

    E-Print Network [OSTI]

    Strathclyde, University of

    ELECTRON MICROPROBE AND PHOTOLUMINESCENCE ANALYSIS OF EUROPIUM-DOPED GALLIUM NITRIDE LIGHT EMITTERSN-on-sapphire epilayers implanted with Europium ions, producing characteristic red emission lines between 540 and 680 nm with energies largely independent of the host material. For example, doping with europium, erbium and thulium

  2. Preconceptual design for separation of plutonium and gallium by ion exchange

    SciTech Connect (OSTI)

    DeMuth, S.F.

    1997-09-30T23:59:59.000Z

    The disposition of plutonium from decommissioned nuclear weapons, by incorporation into commercial UO{sub 2}-based nuclear reactor fuel, is a viable means to reduce the potential for theft of excess plutonium. This fuel, which would be a combination of plutonium oxide and uranium oxide, is referred to as a mixed oxide (MOX). Following power generation in commercial reactors with this fuel, the remaining plutonium would become mixed with highly radioactive fission products in a spent fuel assembly. The radioactivity, complex chemical composition, and large size of this spent fuel assembly, would make theft difficult with elaborate chemical processing required for plutonium recovery. In fabricating the MOX fuel, it is important to maintain current commercial fuel purity specifications. While impurities from the weapons plutonium may or may not have a detrimental affect on the fuel fabrication or fuel/cladding performance, certifying the effect as insignificant could be more costly than purification. Two primary concerns have been raised with regard to the gallium impurity: (1) gallium vaporization during fuel sintering may adversely affect the MOX fuel fabrication process, and (2) gallium vaporization during reactor operation may adversely affect the fuel cladding performance. Consequently, processes for the separation of plutonium from gallium are currently being developed and/or designed. In particular, two separation processes are being considered: (1) a developmental, potentially lower cost and lower waste, thermal vaporization process following PuO{sub 2} powder preparation, and (2) an off-the-shelf, potentially higher cost and higher waste, aqueous-based ion exchange (IX) process. While it is planned to use the thermal vaporization process should its development prove successful, IX has been recommended as a backup process. This report presents a preconceptual design with material balances for separation of plutonium from gallium by IX.

  3. Flexible Ultra Moisture Barrier Film for Thin-Film Photovoltaic Applications

    SciTech Connect (OSTI)

    David M. Dean

    2012-10-30T23:59:59.000Z

    Flexible Thin-film photovoltaic (TFPV) is a low cost alternative to incumbent c-Si PV products as it requires less volume of costly semiconductor materials and it can potentially reduce installation cost. Among the TFPV options, copper indium gallium diselenide (CIGS) has the highest efficiency and is believed to be one of the most attractive candidates to achieve PV cost reduction. However, CIGS cells are very moisture sensitive and require module water vapor transmission rate (WVTR) of less than 1x10-4 gram of water per square meter per day (g-H2O/m2/day). Successful development and commercialization of flexible transparent ultra moisture barrier film is the key to enable flexible CIGS TFPV products, and thus enable ultimate PV cost reduction. At DuPont, we have demonstrated at lab scale that we can successfully make polymer-based flexible transparent ultra moisture barrier film by depositing alumina on polymer films using atomic layer deposition (ALD) technology. The layer by layer ALD approach results in uniform and amorphous structure which effectively reduces pinhole density of the inorganic coating on the polymer, and thus allow the fabrication of flexible barrier film with WVTR of 10-5 g-H2O/m2/day. Currently ALD is a time-consuming process suitable only for high-value, relatively small substrates. To successfully commercialize the ALD-on-plastic technology for the PV industry, there is the need to scale up this technology and improve throughput. The goal of this contract work was to build a prototype demonstrating that the ALD technology could be scaled-up for commercial use. Unfortunately, the prototype failed to produce an ultra-barrier film by the close of the project.

  4. Osteomyelitis and infarction in sickle cell hemoglobinopathies: differentiation by combined technetium and gallium scintigraphy

    SciTech Connect (OSTI)

    Amundsen, T.R.; Siegel, M.J.; Siegel, B.A.

    1984-12-01T23:59:59.000Z

    Clinical records and scintigrams were reviewed of 18 patients with sickle cell hemoglobinophaties who had undergone combined technetium and gallium scintigraphy during 22 separate episodes of suspected osseous infection. The combined scintigrams were correctly interpreted as indicating osteomyelitis in four studies. Of 18 studies in patients with infarction, the combined scintigrams were correctly interpreted in 16 and showed either no local accumulation of Ga-67 or less accumulation than that of Tc-99m MDP at symptomatic sites. In the other two studies, the scintigrams were falsely interpreted as indicating osteomyelitis and showed congruent, increased accumulation of both Tc-99, MDP and Ga-67. This pattern must be considered indeterminate. Overall, the results indicate that the combination of technetium and gallium scintigraphy is an effective means to distinguish osteomyelitis from infarction in patients with sickle cell hemoglobinopathies.

  5. Fast neutron scattering on Gallium target at 14.8 MeV

    E-Print Network [OSTI]

    R. Han; R. Wada; Z. Chen; Y. Nie; X. Liu; S. Zhang; P. Ren; B. Jia; G. Tian; F. Luo; W. Lin; J. Liu; F. Shi; M. Huang; X. Ruan; J. Ren; Z. Zhou; H. Huang; J. Bao; K. Zhang; B. Hu

    2014-11-03T23:59:59.000Z

    Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

  6. Distinctive Signature of Indium Gallium Nitride Quantum Dot Lasing in Microdisks Cavities

    E-Print Network [OSTI]

    Woolf, Alexander; Aharanovich, Igor; Zhu, Tongtong; Niu, Nan; Wang, Danqing; Oliver, Rachel A; Hu, Evelyn L

    2014-01-01T23:59:59.000Z

    Low threshold lasers realized within compact, high quality optical cavities enable a variety of nanophotonics applications. Gallium nitride (GaN) materials containing indium gallium nitride (InGaN) quantum dots and quantum wells offer an outstanding platform to study light matter interactions and realize practical devices such as efficient light emitting diodes and nanolasers. Despite progress in the growth and characterization of InGaN quantum dots, their advantages as the gain medium in low threshold lasers have not been clearly demonstrated. This work seeks to better understand the reasons for these limitations by focusing on the simpler, limited-mode microdisk cavities, and by carrying out comparisons of lasing dynamics in those cavities using varying gain media including InGaN quantum wells, fragmented quantum wells, and a combination of fragmented quantum wells with quantum dots. For each gain medium, we utilize the distinctive, high quality (Q~5500) modes of the cavities, and the change in the highest ...

  7. Fast neutron scattering on Gallium target at 14.8 MeV

    E-Print Network [OSTI]

    Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

    2014-01-01T23:59:59.000Z

    Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

  8. Interaction of hydrogen with gallium vacancies in wurtzite GaN

    SciTech Connect (OSTI)

    Wright, A. F.

    2001-08-01T23:59:59.000Z

    First-principles techniques are used to investigate the interaction of hydrogen with gallium vacancies in wurtzite GaN. The calculations reveal that hydrogen can either compensate a vacancy by donating an electron to a vacancy acceptor level, or passivate the vacancy by forming a hydrogen-vacancy complex. A gallium vacancy can bind up to four hydrogen atoms, and hydrogen removal energies are computed as a function of the number of hydrogen atoms. Removal energies are found to depend strongly on Fermi level and complexes containing more than two hydrogen atoms are predicted to be unstable in n-type GaN. Hydrogen vibration frequencies are computed and compared with previously reported infrared absorption measurements for hydrogen-implanted GaN.

  9. Growth of epitaxial iron nitride ultrathin film on zinc-blende gallium nitride

    SciTech Connect (OSTI)

    Pak, J.; Lin, W.; Wang, K.; Chinchore, A.; Shi, M.; Ingram, D. C.; Smith, A. R.; Sun, K.; Lucy, J. M.; Hauser, A. J.; Yang, F. Y. [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701 (United States); Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Physics, The Ohio State University, 191 Woodruff Avenue, Columbus, Ohio 43210 (United States)

    2010-07-15T23:59:59.000Z

    The authors report the growth of iron nitride on zinc-blende gallium nitride using molecular beam epitaxy. First, zinc-blende GaN is grown on a magnesium oxide substrate having (001) orientation; second, an ultrathin layer of FeN is grown on top of the GaN layer. In situ reflection high-energy electron diffraction is used to monitor the surface during growth, and a well-defined epitaxial relationship is observed. Cross-sectional transmission electron microscopy is used to reveal the epitaxial continuity at the gallium nitride-iron nitride interface. Surface morphology of the iron nitride, similar to yet different from that of the GaN substrate, can be described as plateau valley. The FeN chemical stoichiometry is probed using both bulk and surface sensitive methods, and the magnetic properties of the sample are revealed.

  10. Origin of color centers in the flux-grown europium gallium garnet

    SciTech Connect (OSTI)

    Aleksandrovsky, A. S.; Arkhipkin, V. G.; Bezmaternykh, L. N.; Gudim, I. A.; Krylov, A. S. [L. V. Kirensky Institute of Physics, Akademgorodok, Krasnoyarsk 660036, Russia and Siberian Federal University, Krasnoyarsk 660079 (Russian Federation); Vagizov, F. [Department of Physics, Texas A and M University, College Station, Texas 77840 (United States)

    2008-04-15T23:59:59.000Z

    Europium gallium garnet (EuGG) single crystals were grown from fluxes with various contents. Optical absorption spectra of EuGG grown from a flux containing calcium show an additional band in the ultraviolet and blue regions of the spectra as compared to the case of a calcium-free flux. Moessbauer spectra of the samples grown from the fluxes with different additives show no signs of other valence states of the europium ions except for 3+. However, they indicate changes in the crystal field due to the entrance of additive ions. The nature of the additional absorption must be the same as that for calcium-doped gadolinium gallium garnet, i.e., anion vacancies. Moessbauer isotope shifts and quadrupole splitting for EuGG are determined.

  11. Surface reconstructions of cubic gallium nitride ,,001... grown by radio frequency nitrogen plasma molecular beam epitaxy

    E-Print Network [OSTI]

    observed on c-GaN 001 , depending on the growth condi- tions and the substrate. For growth of c-GaN on Ga-rich-grown GaN 001 on MgO 001 substrate. We have deduced that these variant reconstructions are com- posed of Ga; published online 27 October 2006 Cubic GaN has been grown under gallium Ga -rich growth conditions using

  12. Gallium suboxide vapor attack on chromium, cobalt, molybdenum, tungsten and their alloys at 1200 [degrees] C

    SciTech Connect (OSTI)

    Kolman, D. G. (David G.); Taylor, T. N. (Thomas N.); Park, Y. (Youngsoo); Stan, M. (Marius); Butt, D. P. (Darryl P.); Maggiore, C. J. (Carl J.); Tesmer, Joseph R.; Havrilla, G. J. (George J.)

    2004-01-01T23:59:59.000Z

    Our prior work elucidated the failure mechanism of furnace materi als (304 SS, 316 SS, and Hastelloy C-276) exposed to gallium suboxide (Ga{sub 2}O) and/or gallium oxide (Ga{sub 2}O{sub 3}) during plutonium - gallium compound processing. Failure was hypothesized to result from concurrent alloy oxidation/Ga compound reduction followed by Ga uptake. The aim of the current work is to screen candidate replacement materials. Alloys Haynes 25 (49 Co - 20 Cr - 15 W - 10 Ni - 3 Fe - 2 Mn - 0.4 Si, wt%), 52 Mo - 48 Re (wt%), 62 W - 38 Cu (wt%), and commercially pure Cr, Co, Mo, W, and alumina were examined. Preliminary assessments of commercially pure W and Mo - Re suggest that these materials may be suitable for furnace construction. Thermodynamics calculations indicating that materials containing Al, Cr, Mn, Si, and V would be susceptible to oxidation in the presence of Ga{sub 2}O were validated by experimental results. In contrast to that reported previously, an alternate reaction mechanism for Ga uptake, which does not require concurrent alloy oxidation, controls Ga uptake for certain materials. A correlation between Ga solubility and uptake was noted.

  13. Preparation of gallium nitride surfaces for atomic layer deposition of aluminum oxide

    SciTech Connect (OSTI)

    Kerr, A. J. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States); Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States); Chagarov, E.; Kaufman-Osborn, T.; Kummel, A. C., E-mail: akummel@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States); Gu, S.; Wu, J.; Asbeck, P. M. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States); Madisetti, S.; Oktyabrsky, S. [Department of Nanoscale Science and Engineering, University at Albany–State University of New York, Albany, New York 12222 (United States)

    2014-09-14T23:59:59.000Z

    A combined wet and dry cleaning process for GaN(0001) has been investigated with XPS and DFT-MD modeling to determine the molecular-level mechanisms for cleaning and the subsequent nucleation of gate oxide atomic layer deposition (ALD). In situ XPS studies show that for the wet sulfur treatment on GaN(0001), sulfur desorbs at room temperature in vacuum prior to gate oxide deposition. Angle resolved depth profiling XPS post-ALD deposition shows that the a-Al{sub 2}O{sub 3} gate oxide bonds directly to the GaN substrate leaving both the gallium surface atoms and the oxide interfacial atoms with XPS chemical shifts consistent with bulk-like charge. These results are in agreement with DFT calculations that predict the oxide/GaN(0001) interface will have bulk-like charges and a low density of band gap states. This passivation is consistent with the oxide restoring the surface gallium atoms to tetrahedral bonding by eliminating the gallium empty dangling bonds on bulk terminated GaN(0001)

  14. Gallium-67 complexes as radioactive markers to assess gastric and colonic transit

    SciTech Connect (OSTI)

    Bellen, J.C.; Chatterton, B.E.; Penglis, S.; Tsopelas, C. [Royal Adelaide Hospital (Australia)

    1995-03-01T23:59:59.000Z

    Constipation and gastroparesis are gastrointestinal tract disorders that can be assessed by using radioactive markers in conjunction with scintigraphic techniques. Indium-111-DTPA is the radiopharmaceutical of choice for treating colonic transit in constipated patients, but it is an expensive product and its availability has been unreliable. Indium-113m-DTPA was the tracer used in our study to determine the liquid gastric emptying rate in dual-isotope solid-liquid emptying studies, however, cessation of the {sup 113}Sn/{sup 113m}In generator production makes it unavailable. Thus, development of alternative tracers to {sup 111}In-DTPA and {sup 113m}In-DTPA was essential. Gallium-67-citrate and {sup 67}Ga-EDTA were compared to {sup 111}In-DTPA to assess their efficacy for exclusive retention in the GI tract. These markers were orally administered into rats and their three-day cumulative fecal excretion, urine excretion and carcass retention were measured. An in vitro gastric emptying model was used to determine liquid phase partitioning of {sup 113m}In-DTPA, {sup 67}Ga-citrate and {sup 67}Ga-EDTA at 37{degrees}. Gallium-67-citrate was predominantly excreted in the feces (97.2% {+-} 0.2%) after three days, with negligible urine excretion (0.1% {+-} 0.0%) and carcass retention (0.6% {+-} 0.2%). These results are analogous to those obtained for {sup 111}In-DTPA for fecal excretion (96.7% {+-} 2.6%), urine excretion (0.6% {+-} 0.0%) and retention in the carcass (0.2% {+-} 0.0%). Gallium-67-EDTA showed similar partitioning in the liquid phase of the gastric emptying model compared with {sup 113m}In-DTPA. Gallium-67-citrate is an economical and readily available alternative to {sup 111}In-DTPA as a colonic transit radiopharmaceutical. Gallium-67-EDTA is also an alternative to {sup 113m}In-DTPA for assessing liquid-phase emptying in a dual-isotope solid/liquid gastric emptying study. 17 refs., 3 figs., 2 tabs.

  15. (Polyfluoroaryl)fluoroanions of aluminum, gallium, and indium of enhanced utility, uses thereof, and products based thereon

    DOE Patents [OSTI]

    Marks, Tobin J. (Evanston, IL); Chen, You-Xian (Midland, MI)

    2001-01-01T23:59:59.000Z

    The (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are novel weakly coordinating anions which are are highly fluorinated. (Polyfluoroaryl)fluoroanions of one such type contain at least one ring substituent other than fluorine. These (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium have greater solubility in organic solvents, or have a coordinative ability essentially equal to or less than that of the corresponding (polyfluoroaryl)fluoroanion of aluminum, gallium, or indium in which the substituent is replaced by fluorine. Another type of new (polyfluoroaryl)fluoroanion of aluminum, gallium, and indium have 1-3 perfluorinated fused ring groups and 2-0 perfluorophenyl groups. When used as a cocatalyst in the formation of novel catalytic complexes with d- or f-block metal compounds having at least one leaving group such as a methyl group, these anions, because of their weak coordination to the metal center, do not interefere in the ethylene polymerization process, while affecting the the propylene process favorably, if highly isotactic polypropylene is desired. Thus, the (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium of this invention are useful in various polymerization processes such as are described.

  16. Fabrication of optoelectronic microwave linear and ring resonators on a gallium arsenide substrate

    E-Print Network [OSTI]

    Yeh, Chun-Liang

    1993-01-01T23:59:59.000Z

    for the degree of MASTER OF SCIENCE August 1993 Major Subject: Electrical Engineering FABRICATION OF OPTOELECTRONIC MICROWAVE LINEAR AND RING RESONATORS ON A GALLIUM ARSENIDE SUBSTRATE A Thesis by CHUN-LIANG YEH Approved as to style and content by: Mark... and the first modes at 4. 87, 4. 89, 4. 91 GHz have been designed, simulated, and fabricated on a GaAs substrate. A microstrip ring resonator with 3/4 pm coupling gaps and the first mode at 3. 456 GHz also has been fabricated on GaAs. A reliable high yield...

  17. Process development for the fabrication of monolithic optoelectronic resonators on gallium arsenide substrates

    E-Print Network [OSTI]

    Fairchild, Brock Wilson

    1990-01-01T23:59:59.000Z

    with fairly good adhension prop- erties with gallium arsenide and gold. A layer of nickel was deposited on top of the AuGe to reduce the GaAs/AuGe interfacial strain that causes the AuGe to peal during plating. Good adhesion can be formed with GaAs when Au.... 57 LIST OF FIGURES FIGURE Page Typical ring resonator with coupled feed lines. Width/height ratio of photoresist in the gap region. Process steps for the fabrication of resonating structures. (a). Deposition of AuGe and nickel. (b). Spin...

  18. Bulk measurement of copper and sodium content in CuIn(0.7)Ga(0.3)Se(2) (CIGS) solar cells with nanosecond pulse length laser induced breakdown spectroscopy (LIBS)

    E-Print Network [OSTI]

    Kowalczyk, Jeremy M D; DeAngelis, Alexander; Kaneshiro, Jess; Mallory, Stewart A; Chang, Yuancheng; Gaillard, Nicolas

    2013-01-01T23:59:59.000Z

    In this work, we show that laser induced breakdown spectroscopy (LIBS) with a nanosecond pulse laser can be used to measure the copper and sodium content of CuIn(0.7)Ga(0.3)Se(2) (CIGS) thin film solar cells on molybdenum. This method has four significant advantages over methods currently being employed: the method is inexpensive, measurements can be taken in times on the order of one second, without high vacuum, and at distances up to 5 meters or more. The final two points allow for in-line monitoring of device fabrication in laboratory or industrial environments. Specifically, we report a linear relationship between the copper and sodium spectral lines from LIBS and the atomic fraction of copper and sodium measured via secondary ion mass spectroscopy (SIMS), discuss the ablation process of this material with a nanosecond pulse laser compared to shorter pulse duration lasers, and examine the depth resolution of nanosecond pulse LIBS.

  19. Journal of Crystal Growth 294 (2006) 231235 In situ investigation on selenization kinetics of CuIn precursor using

    E-Print Network [OSTI]

    Anderson, Timothy J.

    2006-01-01T23:59:59.000Z

    Keywords: A1. X-ray diffraction; B1. Copper indium diselenide; B3. Solar cells 1. Introduction Chalcopyrite film solar cells. The commonly used techniques for CuInSe2 layer formation are co, reaction mechanisms, and kinetics for the formation of Cu(InxGa1Àx)Se2 (CIGS) and its sub- ternaries (i

  20. Dynamics of formation of photoresponse in a detector structure made of gallium arsenide

    SciTech Connect (OSTI)

    Ayzenshtat, G. I., E-mail: ayzen@mail.tomsknet.ru; Lelekov, M. A.; Tolbanov, O. P. [Tomsk State University (Russian Federation)

    2008-04-15T23:59:59.000Z

    The influence of capture effects on the characteristics of detectors of the ionizing radiation based on semi-insulating gallium arsenide is considered. Generation of nonequilibrium electrons and holes along the entire thickness of the active region was performed under illumination with an infrared light-emitting diode with a wavelength of 0.9 {mu}m. In this case, the situation emerging in the device structure under the effect of X-ray radiation or a high-energy electron beam was simulated. It is shown that the variation in the shape of the output signal with time in this case is caused by variation in the electric field profile due to the capture of holes at deep centers in gallium arsenide. An absolutely different distribution of the electric field emerges in the structure under irradiation of a semitransparent cathode of the structure with a red light-emitting diode, emission of which penetrates into the active region for mere 1 {mu}m. In this case, the transformation of the electric field is caused by the capture of electrons. Under the prolonged effect of such radiation, a space-charge-limited current mode emerges in the device.

  1. Anionic Gallium-Based Metal;#8722;Organic Framework and Its Sorption and Ion-Exchange Properties

    SciTech Connect (OSTI)

    Banerjee, Debasis; Kim, Sun Jin; Wu, Haohan; Xu, Wenqian; Borkowski, Lauren A.; Li, Jing; Parise, John B. (Kwangju); (Rutgers); (SBU)

    2012-04-30T23:59:59.000Z

    A gallium-based metal-organic framework Ga{sub 6}(C{sub 9}H{sub 3}O{sub 6}){sub 8} {center_dot} (C{sub 2}H{sub 8}N){sub 6}(C{sub 3}H{sub 7}NO){sub 3}(H{sub 2}O){sub 26} [1, Ga{sub 6}(1,3,5-BTC){sub 8} {center_dot} 6DMA {center_dot} 3DMF {center_dot} 26H{sub 2}O], GaMOF-1; BTC = benzenetricarboxylate/trimesic acid and DMA = dimethylamine, with space group I{bar 4}3d, a = 19.611(1) {angstrom}, and V = 7953.4(6) {angstrom}{sup 3}, was synthesized using solvothermal techniques and characterized by synchrotron-based X-ray microcrystal diffraction. Compound 1 contains isolated gallium tetrahedra connected by the organic linker (BTC) forming a 3,4-connected anionic porous network. Disordered positively charged ions and solvent molecules are present in the pore, compensating for the negative charge of the framework. These positively charged molecules could be exchanged with alkali-metal ions, as is evident by an ICP-MS study. The H{sub 2} storage capacity of the parent framework is moderate with a H{sub 2} storage capacity of {approx}0.5 wt % at 77 K and 1 atm.

  2. An assessment of the validity of cerium oxide as a surrogate for plutonium oxide gallium removal studies

    SciTech Connect (OSTI)

    Kolman, D.G.; Park, Y.; Stan, M.; Hanrahan, R.J. Jr.; Butt, D.P.

    1999-03-01T23:59:59.000Z

    Methods for purifying plutonium metal have long been established. These methods use acid solutions to dissolve and concentrate the metal. However, these methods can produce significant mixed waste, that is, waste containing both radioactive and chemical hazards. The volume of waste produced from the aqueous purification of thousands of weapons would be expensive to treat and dispose. Therefore, a dry method of purification is highly desirable. Recently, a dry gallium removal research program commenced. Based on initial calculations, it appeared that a particular form of gallium (gallium suboxide, Ga{sub 2}O) could be evaporated from plutonium oxide in the presence of a reducing agent, such as small amounts of hydrogen dry gas within an inert environment. Initial tests using ceria-based material (as a surrogate for PuO{sub 2}) showed that thermally-induced gallium removal (TIGR) from small samples (on the order of one gram) was indeed viable. Because of the expense and difficulty of optimizing TIGR from plutonium dioxide, TIGR optimization tests using ceria have continued. This document details the relationship between the ceria surrogate tests and those conducted using plutonia.

  3. Tripodal aminophenolate ligand complexes of aluminum(III), gallium(III), and indium(III) in water

    SciTech Connect (OSTI)

    Caravan, P.; Orvig, C. [Univ. of British Columbia, Vancouver (Canada)] [Univ. of British Columbia, Vancouver (Canada)

    1997-01-15T23:59:59.000Z

    This article focuses on the development of radiopharmaceuticals using new chelators of gallium and indium. The radionuclide kinetics and demetalation kinetics are of great consideration. This work explored the effects of ligand backbone variations on the selectivity of multidentate aminophenolate ligands among the trivalent metal ions Al(III), Ga(III) and In(III) in water. 54 refs., 16 figs., 3 tabs.

  4. Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride by metalorganic vapor-phase epitaxy

    E-Print Network [OSTI]

    Li, Lian

    Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride to examine the effects of carbon tetrachloride concentration and temperature on the morphology of carbon with increasing carbon tetrachloride concentration. Step bunching and pinning was observed at a IV/III ratio

  5. Simulation assisted design of a gallium phosphide np photovoltaic junction Charles R. Allen, Jong-Hyeok Jeon , Jerry M. Woodall

    E-Print Network [OSTI]

    Woodall, Jerry M.

    University, 1205 W State Street, West Lafayette, IN, USA a r t i c l e i n f o Article history: Received 27 February 2010 Keywords: Gallium phosphide Solar cell Multi-junction CPV Simulation a b s t r a c with measurements of the dark and light response. The light current was measured under an illumination of air mass

  6. Organometallic vapor-phase homoepitaxy of gallium arsenide assisted by a downstream hydrogen afterglow plasma in the growth region

    E-Print Network [OSTI]

    Collins, George J.

    Organometallic vapor-phase homoepitaxy of gallium arsenide assisted by a downstream hydrogen 1991; accepted for publication 3 April 1992) hz situ generated arsenic hydrides are reacted downstream with trimethylgallium (TMGa), both in the presence of and in the absence of a downstream hydrogen afterglow plasma. The

  7. Scanning Tunneling Microscopy and Surface Simulation of Zinc-Blende GaN(001) Intrinsic 4 Reconstruction: Linear Gallium Tetramers?

    E-Print Network [OSTI]

    Reconstruction: Linear Gallium Tetramers? Hamad A. AL-Brithen, Rong Yang, Muhammad B. Haider, Costel Constantin and occupied states, in agreement with surface simulations based on the 4 1 linear tetramer model the existence of linear Ga tetramers. DOI: PACS numbers: 68.35.Bs, 68.37.Ef, 73.20.At Based on both fundamental

  8. Silicon Oxynitride Thin Film Barriers for PV Packaging (Poster)

    SciTech Connect (OSTI)

    del Cueto, J. A.; Glick, S. H.; Terwilliger, K. M.; Jorgensen, G. J.; Pankow, J. W.; Keyes, B. M.; Gedvilas, L. M.; Pern, F. J.

    2006-10-03T23:59:59.000Z

    Dielectric, adhesion-promoting, moisture barriers comprised of silicon oxynitride thin film materials (SiOxNy with various material stoichiometric compositions x,y) were applied to: 1) bare and pre-coated soda-lime silicate glass (coated with transparent conductive oxide SnO2:F and/or aluminum), and polymer substrates (polyethylene terephthalate, PET, or polyethylene napthalate, PEN); plus 2) pre- deposited photovoltaic (PV) cells and mini-modules consisting of amorphous silicon (a-Si) and copper indium gallium diselenide (CIGS) thin-film PV technologies. We used plasma enhanced chemical vapor deposition (PECVD) process with dilute silane, nitrogen, and nitrous oxide/oxygen gas mixtures in a low-power (< or = 10 milliW per cm2) RF discharge at ~ 0.2 Torr pressure, and low substrate temperatures < or = 100(degrees)C, over deposition areas ~ 1000 cm2. Barrier properties of the resulting PV cells and coated-glass packaging structures were studied with subsequent stressing in damp-heat exposure at 85(degrees)C/85% RH. Preliminary results on PV cells and coated glass indicate the palpable benefits of the barriers in mitigating moisture intrusion and degradation of the underlying structures using SiOxNy coatings with thicknesses in the range of 100-200 nm.

  9. In situ analyses on negative ions in the indium-gallium-zinc oxide sputtering process

    SciTech Connect (OSTI)

    Jia, Junjun; Torigoshi, Yoshifumi; Shigesato, Yuzo [Graduate School of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5258 (Japan)

    2013-07-01T23:59:59.000Z

    The origin of negative ions in the dc magnetron sputtering process using a ceramic indium-gallium-zinc oxide target has been investigated by in situ analyses. The observed negative ions are mainly O{sup -} with energies corresponding to the target voltage, which originates from the target and barely from the reactive gas (O{sub 2}). Dissociation of ZnO{sup -}, GaO{sup -}, ZnO{sub 2}{sup -}, and GaO{sub 2}{sup -} radicals also contributes to the total negative ion flux. Furthermore, we find that some sputtering parameters, such as the type of sputtering gas (Ar or Kr), sputtering power, total gas pressure, and magnetic field strength at the target surface, can be used to control the energy distribution of the O{sup -} ion flux.

  10. Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen

    SciTech Connect (OSTI)

    Sallis, S.; Williams, D. S. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States); Butler, K. T.; Walsh, A. [Center for Sustainable Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Quackenbush, N. F. [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Junda, M.; Podraza, N. J. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Fischer, D. A.; Woicik, J. C. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); White, B. E.; Piper, L. F. J., E-mail: lpiper@binghamton.edu [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

    2014-06-09T23:59:59.000Z

    The origin of the deep subgap states in amorphous indium gallium zinc oxide (a-IGZO), whether intrinsic to the amorphous structure or not, has serious implications for the development of p-type transparent amorphous oxide semiconductors. We report that the deep subgap feature in a-IGZO originates from local variations in the oxygen coordination and not from oxygen vacancies. This is shown by the positive correlation between oxygen composition and subgap intensity as observed with X-ray photoelectron spectroscopy. We also demonstrate that the subgap feature is not intrinsic to the amorphous phase because the deep subgap feature can be removed by low-temperature annealing in a reducing environment. Atomistic calculations of a-IGZO reveal that the subgap state originates from certain oxygen environments associated with the disorder. Specifically, the subgap states originate from oxygen environments with a lower coordination number and/or a larger metal-oxygen separation.

  11. Structure and electrical characterization of gallium arsenide nanowires with different V/III ratio growth parameters

    SciTech Connect (OSTI)

    Muhammad, R.; Ahamad, R. [Sustainability Research Alliance, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Ibrahim, Z.; Othaman, Z. [Physic Department, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2014-03-05T23:59:59.000Z

    Gallium arsenide (GaAs) nanowires were grown vertically on GaAs(111)B substrate by gold-assisted using metal-organic chemical vapour deposition. Field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and conductivity atomic force microscopy (CAFM) analysis were carried out to investigate the effects of V/III ratio on structural properties and current-voltage changes in the wires. Results show that GaAs NWs grow preferably in the wurtzite crystal structure than zinc blende crystal structure with increasing V/III ratio. Additionally, CAFM studies have revealed that zincblende nanowires indicate ohmic characteristic compared to oscillation current occurred for wurtzite structures. The GaAs NWs with high quality structures are needed in solar cells technology for trapping energy that directly converts of sunlight into electricity with maximum capacity.

  12. Outdoor Performance of a Thin-Film Gallium-Arsenide Photovoltaic Module

    SciTech Connect (OSTI)

    Silverman, T. J.; Deceglie, M. G.; Marion, B.; Cowley, S.; Kayes, B.; Kurtz, S.

    2013-06-01T23:59:59.000Z

    We deployed a 855 cm2 thin-film, single-junction gallium arsenide (GaAs) photovoltaic (PV) module outdoors. Due to its fundamentally different cell technology compared to silicon (Si), the module responds differently to outdoor conditions. On average during the test, the GaAs module produced more power when its temperature was higher. We show that its maximum-power temperature coefficient, while actually negative, is several times smaller in magnitude than that of a Si module used for comparison. The positive correlation of power with temperature in GaAs is due to temperature-correlated changes in the incident spectrum. We show that a simple correction based on precipitable water vapor (PWV) brings the photocurrent temperature coefficient into agreement with that measured by other methods and predicted by theory. The low operating temperature and small temperature coefficient of GaAs give it an energy production advantage in warm weather.

  13. Analysis of gallium arsenide deposition in a horizontal chemical vapor deposition reactor using massively parallel computations

    SciTech Connect (OSTI)

    Salinger, A.G.; Shadid, J.N.; Hutchinson, S.A. [and others

    1998-01-01T23:59:59.000Z

    A numerical analysis of the deposition of gallium from trimethylgallium (TMG) and arsine in a horizontal CVD reactor with tilted susceptor and a three inch diameter rotating substrate is performed. The three-dimensional model includes complete coupling between fluid mechanics, heat transfer, and species transport, and is solved using an unstructured finite element discretization on a massively parallel computer. The effects of three operating parameters (the disk rotation rate, inlet TMG fraction, and inlet velocity) and two design parameters (the tilt angle of the reactor base and the reactor width) on the growth rate and uniformity are presented. The nonlinear dependence of the growth rate uniformity on the key operating parameters is discussed in detail. Efficient and robust algorithms for massively parallel reacting flow simulations, as incorporated into our analysis code MPSalsa, make detailed analysis of this complicated system feasible.

  14. NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01T23:59:59.000Z

    Researchers at the National Renewable Energy Laboratory (NREL) are finding new ways to manufacture thin-film solar cells made from copper, indium, gallium, and selenium - called CIGS cells - that are different than conventional CIGS solar cells. Their use of high-temperature glass, designed by SCHOTT AG, allows higher fabrication temperatures, opening the door to new CIGS solar cells employing light-absorbing materials with wide 'bandgaps.'

  15. Structural and electronic properties of -In2X3 (X=O, S, Se, Te) using ab initio calculations

    E-Print Network [OSTI]

    Khare, Sanjay V.

    by NREL [1]. CdS is one of the important layers in fabricating CIGS solar cells but poses ecological and environmentally friendly copper­indium­gallium­selenide solar cells and molecules. Here we have studied been investigated. © 2011 Elsevier B.V. All rights reserved. Introduction Cu­In­Ga­S (CIGS) based solar

  16. Investigation on properties of ultrafast switching in a bulk gallium arsenide avalanche semiconductor switch

    SciTech Connect (OSTI)

    Hu, Long, E-mail: hulong-1226@126.com [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China); Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Su, Jiancang; Ding, Zhenjie; Hao, Qingsong; Yuan, Xuelin [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

    2014-03-07T23:59:59.000Z

    Properties of ultrafast switching in a bulk gallium arsenide (GaAs) avalanche semiconductor switch based on semi-insulating wafer, triggered by an optical pulse, were analyzed using physics-based numerical simulations. It has been demonstrated that when a voltage with amplitude of 5.2?kV is applied, after an exciting optical pulse with energy of 1??J arrival, the structure with thickness of 650??m reaches a high conductivity state within 110 ps. Carriers are created due to photons absorption, and electrons and holes drift to anode and cathode terminals, respectively. Static ionizing domains appear both at anode and cathode terminals, and create impact-generated carriers which contribute to the formation of electron-hole plasma along entire channel. When the electric field in plasma region increases above the critical value (?4?kV/cm) at which the electrons drift velocity peaks, a domain comes into being. An increase in carrier concentration due to avalanche multiplication in the domains reduces the domain width and results in the formation of an additional domain as soon as the field outside the domains increases above ?4?kV/cm. The formation and evolution of multiple powerfully avalanching domains observed in the simulations are the physical reasons of ultrafast switching. The switch exhibits delayed breakdown with the characteristics affected by biased electric field, current density, and optical pulse energy. The dependence of threshold energy of the exciting optical pulse on the biased electric field is discussed.

  17. Electronic passivation of silicon surfaces by thin films of atomic layer deposited gallium oxide

    SciTech Connect (OSTI)

    Allen, T. G., E-mail: thomas.allen@anu.edu.au; Cuevas, A. [Research School of Engineering, Australian National University, Canberra 0200 (Australia)

    2014-07-21T23:59:59.000Z

    This paper proposes the application of gallium oxide (Ga{sub 2}O{sub 3}) thin films to crystalline silicon solar cells. Effective passivation of n- and p-type crystalline silicon surfaces has been achieved by the application of very thin Ga{sub 2}O{sub 3} films prepared by atomic layer deposition using trimethylgallium (TMGa) and ozone (O{sub 3}) as the reactants. Surface recombination velocities as low as 6.1?cm/s have been recorded with films less than 4.5?nm thick. A range of deposition parameters has been explored, with growth rates of approximately 0.2?Å/cycle providing optimum passivation. The thermal activation energy for passivation of the Si-Ga{sub 2}O{sub 3} interface has been found to be approximately 0.5?eV. Depassivation of the interface was observed for prolonged annealing at increased temperatures. The activation energy for depassivation was measured to be 1.9?eV.

  18. Gallium ion implantation greatly reduces thermal conductivity and enhances electronic one of ZnO nanowires

    SciTech Connect (OSTI)

    Xia, Minggang, E-mail: xiamg@mail.xjtu.edu.cn [Laboratory of Nanostructure and its Physics Properties, Department of Optical Information Science and Technology, Department of Applied Physics, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 China (China); Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Cheng, Zhaofang; Han, Jinyun; Zhang, Shengli [Laboratory of Nanostructure and its Physics Properties, Department of Optical Information Science and Technology, Department of Applied Physics, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 China (China); Zheng, Minrui [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Sow, Chorng-Haur [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); National University of Singapore Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117542 (Singapore); Thong, John T. L. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Li, Baowen [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); National University of Singapore Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117542 (Singapore); Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China)

    2014-05-15T23:59:59.000Z

    The electrical and thermal conductivities are measured for individual zinc oxide (ZnO) nanowires with and without gallium ion (Ga{sup +}) implantation at room temperature. Our results show that Ga{sup +} implantation enhances electrical conductivity by one order of magnitude from 1.01 × 10{sup 3} ?{sup ?1}m{sup ?1} to 1.46 × 10{sup 4} ?{sup ?1}m{sup ?1} and reduces its thermal conductivity by one order of magnitude from 12.7 Wm{sup ?1}K{sup ?1} to 1.22 Wm{sup ?1}K{sup ?1} for ZnO nanowires of 100 nm in diameter. The measured thermal conductivities are in good agreement with those in theoretical simulation. The increase of electrical conductivity origins in electron donor doping by Ga{sup +} implantation and the decrease of thermal conductivity is due to the longitudinal and transverse acoustic phonons scattering by Ga{sup +} point scattering. For pristine ZnO nanowires, the thermal conductivity decreases only two times when its diameter reduces from 100 nm to 46 nm. Therefore, Ga{sup +}-implantation may be a more effective method than diameter reduction in improving thermoelectric performance.

  19. Crystal structure and electron microprobe analyses of a lanthanum lutetium gallium garnet

    SciTech Connect (OSTI)

    Parise, J.B.; Harlow, R.L.; Shannon, R.D. (Central Research and Development Department, E. I. DuPont De Nemours and Co., Experimental Station, Wilmington, Delaware 19880-0228 (United States)); Kwei, G.H. (LANSCE, MS-H805, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Allik, T.H. (Science Applications International Corporation, 1710 Goodridge Dr., P.O. Box 1303, McLean, Virginia 22102 (United States)); Armstrong, J.T. (Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 (United States))

    1992-09-15T23:59:59.000Z

    Single-crystal electron microprobe analysis of a lanthanum lutetium gallium garnet has resulted in a composition of La{sub 2.37}Nd{sub 0.07}Pb{sub 0.01}Lu{sub 2.54}Cr{sub 0.01} Ga{sub 3.00}O{sub 12}. This composition gives better agreement between observed and calculated total dielectric polarizabilities than previously reported compositions (La{sub 2.26--2.32}Nd{sub 0.04}Lu{sub 2.57--2.63}Ga{sub 3.07}O{sub 12} by x-ray fluorescence and La{sub 2.655}Nd{sub 0.027}Lu{sub 2.656}Ga{sub 2.655}O{sub 12} by inductively coupled plasma analyses), and does not imply the crystal-chemically improbable presence of Lu{sup 3+} in the tetrahedral site. X-ray and neutron crystal-structure analyses have confirmed that little or no Lu resides in this site.

  20. Optical waveguiding properties into porous gallium nitride structures investigated by prism coupling technique

    SciTech Connect (OSTI)

    Alshehri, Bandar; Dogheche, Elhadj, E-mail: elhadj.dogheche@univ-valenciennes.fr [Institute Electronics, Microelectronics and Nanotechnology (IEMN CNRS), University of Valenciennes, Villeneuve d'Ascq (France); Lee, Seung-Min; Kang, Jin-Ho; Ryu, Sang-Wan, E-mail: sangwan@chonnam.ac.kr [Department of Physics, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Gong, Su-Hyun; Cho, Yong-Hoon [Department of Physics and KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of)

    2014-08-04T23:59:59.000Z

    In order to modulate the refractive index and the birefringence of Gallium Nitride (GaN), we have developed a chemical etching method to perform porous structures. The aim of this research is to demonstrate that optical properties of GaN can be tuned by controlling the pores density. GaN films are prepared on sapphire by metal organic chemical vapor deposition and the microstructure is characterized by transmission electron microscopy, and scanning electron microscope analysis. Optical waveguide experiment is demonstrated here to determine the key properties as the ordinary (n{sub 0}) and extraordinary (n{sub e}) refractive indices of etched structures. We report here the dispersion of refractive index for porous GaN and compare it to the bulk material. We observe that the refractive index decreases when the porous density p is increased: results obtained at 0.975??m have shown that the ordinary index n{sub 0} is 2.293 for a bulk layer and n{sub 0} is 2.285 for a pores density of 20%. This value corresponds to GaN layer with a pore size of 30?nm and inter-distance of 100?nm. The control of the refractive index into GaN is therefore fundamental for the design of active and passive optical devices.

  1. Optimal composition of europium gallium oxide thin films for device applications

    SciTech Connect (OSTI)

    Wellenius, P.; Muth, J. F. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Smith, E. R. [Kratos Defense and Security Solutions, Inc., 5030 Bradford Drive, Huntsville, Alabama 35805 (United States); LeBoeuf, S. M. [Valencell, Inc., 920 Main Campus Drive, Raleigh, North Carolina 27615 (United States); Everitt, H. O. [Army Aviation and Missile RD and E Center, Redstone Arsenal, Alabama 35898 (United States) and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2010-05-15T23:59:59.000Z

    Europium gallium oxide (Eu{sub x}Ga{sub 1-x}){sub 2}O{sub 3} thin films were deposited on sapphire substrates by pulsed laser deposition with varying Eu content from x=2.4 to 20 mol %. The optical and physical effects of high europium concentration on these thin films were studied using photoluminescence (PL) spectroscopy, x-ray diffraction (XRD), and Rutherford backscattering spectrometry. PL spectra demonstrate that emission due to the {sup 5}D{sub 0} to {sup 7}F{sub J} transitions in Eu{sup 3+} grows linearly with Eu content up to 10 mol %. Time-resolved PL indicates decay parameters remain similar for films with up to 10 mol % Eu. At 20 mol %, however, PL intensity decreases substantially and PL decay accelerates, indicative of parasitic energy transfer processes. XRD shows films to be polycrystalline and beta-phase for low Eu compositions. Increasing Eu content beyond 5 mol % does not continue to modify the film structure and thus, changes in PL spectra and decay cannot be attributed to structural changes in the host. These data indicate the optimal doping for optoelectronic devices based on (Eu{sub x}Ga{sub 1-x}){sub 2}O{sub 3} thin films is between 5 and 10 mol %.

  2. Shear strain mediated magneto-electric effects in composites of piezoelectric lanthanum gallium silicate or tantalate and ferromagnetic alloys

    SciTech Connect (OSTI)

    Sreenivasulu, G.; Piskulich, E.; Srinivasan, G., E-mail: srinivas@oakland.edu [Physics Department, Oakland University, Rochester, Michigan 48409 (United States); Qu, P.; Qu, Hongwei [Electrical and Computer Engineering, Oakland University, Rochester, Michigan 48309 (United States); Petrov, V. M. [Institute of Electronic Information Systems, Novgorod State University, Veliky Novgorod (Russian Federation); Fetisov, Y. K. [Moscow State Technical University of Radio Engineering, Electronics and Automation, Moscow 19454 (Russian Federation); Nosov, A. P. [Institute of Metal Physics, Ural Division of Russian Academy of Sciences, 18 S. Kovalevskaya St, Ekaterinburg 620990 (Russian Federation)

    2014-07-21T23:59:59.000Z

    Shear strain mediated magneto-electric (ME) coupling is studied in composites of piezoelectric Y-cut lanthanum gallium silicate (LGS) or tantalate (LGT) and ferromagnetic Fe-Co-V alloys. It is shown that extensional strain does not result in ME effects in these layered composites. Under shear strain generated by an ac and dc bias magnetic fields along the length and width of the sample, respectively, strong ME coupling is measured at low-frequencies and at mechanical resonance. A model is discussed for the ME effects. These composites of Y-cut piezoelectrics and ferromagnetic alloys are of importance for shear strain based magnetic field sensors.

  3. A numerical simulation study of gallium-phosphide/silicon heterojunction passivated emitter and rear solar cells

    SciTech Connect (OSTI)

    Wagner, Hannes [Department of Solar Energy, Institute Solid-State Physics, Leibniz University of Hannover, Appelstr. 2, 30167 Hannover (Germany); ARC Photovoltaics Centre of Excellence, University of New South Wales (UNSW), Sydney, NSW 2052 (Australia); Ohrdes, Tobias [Institute for Solar Energy Research Hamelin (ISFH), 31860 Emmerthal (Germany); Dastgheib-Shirazi, Amir [Div. Photovoltaics, Department of Physics, University of Konstanz, 78457 Konstanz (Germany); Puthen-Veettil, Binesh; König, Dirk [ARC Photovoltaics Centre of Excellence, University of New South Wales (UNSW), Sydney, NSW 2052 (Australia); Altermatt, Pietro P. [Department of Solar Energy, Institute Solid-State Physics, Leibniz University of Hannover, Appelstr. 2, 30167 Hannover (Germany)

    2014-01-28T23:59:59.000Z

    The performance of passivated emitter and rear (PERC) solar cells made of p-type Si wafers is often limited by recombination in the phosphorus-doped emitter. To overcome this limitation, a realistic PERC solar cell is simulated, whereby the conventional phosphorus-doped emitter is replaced by a thin, crystalline gallium phosphide (GaP) layer. The resulting GaP/Si PERC cell is compared to Si PERC cells, which have (i) a standard POCl{sub 3} diffused emitter, (ii) a solid-state diffused emitter, or (iii) a high efficiency ion-implanted emitter. The maximum efficiencies for these realistic PERC cells are between 20.5% and 21.2% for the phosphorus-doped emitters (i)–(iii), and up to 21.6% for the GaP emitter. The major advantage of this GaP hetero-emitter is a significantly reduced recombination loss, resulting in a higher V{sub oc}. This is so because the high valence band offset between GaP and Si acts as a nearly ideal minority carrier blocker. This effect is comparable to amorphous Si. However, the GaP layer can be contacted with metal fingers like crystalline Si, so no conductive oxide is necessary. Compared to the conventional PERC structure, the GaP/Si PERC cell requires a lower Si base doping density, which reduces the impact of the boron-oxygen complexes. Despite the lower base doping, fewer rear local contacts are necessary. This is so because the GaP emitter shows reduced recombination, leading to a higher minority electron density in the base and, in turn, to a higher base conductivity.

  4. Real-time x-ray studies of gallium nitride nanodot formation by droplet heteroepitaxy

    SciTech Connect (OSTI)

    Wang Yiyi; Oezcan, Ahmet S.; Sanborn, Christopher; Ludwig, Karl F.; Bhattacharyya, Anirban; Chandrasekaran, Ramya; Moustakas, Theodore D.; Zhou Lin; Smith, David J. [Physics Department, Boston University, Boston, Massachusetts 02215 (United States); Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States); Department of Physics, Arizona State University, Tempe, Arizona 85287, USA and School of Materials, Arizona State University, Tempe, Arizona 85287 (United States)

    2007-10-01T23:59:59.000Z

    Self-organized gallium nitride nanodots have been fabricated using droplet heteroepitaxy on c-plane sapphire by plasma-assisted molecular beam epitaxy at different substrate temperatures and Ga fluxes. Nanoscale Ga droplets were initially formed on the sapphire substrate at high temperatures by Ga deposition from an effusion cell in an ultrahigh vacuum growth chamber. Subsequently, the droplets were converted into GaN nanodots using a nitrogen plasma source. The process was monitored and controlled using real-time grazing-incidence small-angle x-ray scattering. The samples were examined postgrowth by in situ grazing incidence x-ray diffraction and reflection high-energy electron diffraction, which confirmed the epitaxial relationship between the GaN nanodots and the sapphire surface. X-ray diffraction indicated that the wurtzite phase was dominant at higher substrate temperature (710 deg. C), but a mixture of wurtzite and zinc blende phases was present at a substrate temperature of 620 deg. C. Ex situ atomic force microscopy and transmission electron microscopy analyses showed that the dot size distribution was bimodal. A thin GaN continuous layer of {approx} three monolayers thick was observed by transmission electron microscopy on the sample grown at a substrate temperature of 620 deg. C, but no such layer was observed for the substrate temperature of 710 deg. C. This suggests that there is little mobility of Ga atoms in contact with the sapphire substrate at the lower temperature so that they cannot easily diffuse to nearby droplets and instead form a thin layer covering the surface.

  5. Real-Time X-ray Studies of Gallium Nitride Nanodot Formation by Droplet Heteroepitaxy

    SciTech Connect (OSTI)

    Wang,Y.; Ozcan, A.; Sanborn, C.; Ludwig, K.; Bhattacharyya, A.; Chandrasekaran, R.; Moustakas, T.; Zhou, L.; Smith, D.

    2007-01-01T23:59:59.000Z

    Self-organized gallium nitride nanodots have been fabricated using droplet heteroepitaxy on c-plane sapphire by plasma-assisted molecular beam epitaxy at different substrate temperatures and Ga fluxes. Nanoscale Ga droplets were initially formed on the sapphire substrate at high temperatures by Ga deposition from an effusion cell in an ultrahigh vacuum growth chamber. Subsequently, the droplets were converted into GaN nanodots using a nitrogen plasma source. The process was monitored and controlled using real-time grazing-incidence small-angle x-ray scattering. The samples were examined postgrowth by in situ grazing incidence x-ray diffraction and reflection high-energy electron diffraction, which confirmed the epitaxial relationship between the GaN nanodots and the sapphire surface. X-ray diffraction indicated that the wurtzite phase was dominant at higher substrate temperature (710? C), but a mixture of wurtzite and zinc blende phases was present at a substrate temperature of 620? C. Ex situ atomic force microscopy and transmission electron microscopy analyses showed that the dot size distribution was bimodal. A thin GaN continuous layer of ? three monolayers thick was observed by transmission electron microscopy on the sample grown at a substrate temperature of 620? C, but no such layer was observed for the substrate temperature of 710? C. This suggests that there is little mobility of Ga atoms in contact with the sapphire substrate at the lower temperature so that they cannot easily diffuse to nearby droplets and instead form a thin layer covering the surface.

  6. Synthesis of Germanium-Gallium-Tellurium (Ge-Ga-Te) ceramics by ball-milling and sintering Mathieu Hubert, Elena Petracovschi, Xiang-Hua Zhang and Laurent Calvez*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Synthesis of Germanium-Gallium-Tellurium (Ge-Ga-Te) ceramics by ball-milling and sintering Mathieu, France *laurent.calvez@univ-rennes1.fr Tel: (33) 2 23 23 67 13 Fax: (33) 2 23 23 56 11 Abstract, the semiconductor behavior of CdTe is exploited for the production of solar panels [1, 2], the rapid and reversible

  7. The reaction of carbon tetrachloride with gallium arsenide ,,001... L. Li., S, Gan, B.-K. Han, H. Qi, and R. F. Hicksa)

    E-Print Network [OSTI]

    Li, Lian

    The reaction of carbon tetrachloride with gallium arsenide ,,001... L. Li., S, Gan, B.-K. Han, H, California 90095 Received 26 June 1997; accepted for publication 30 December 1997 Carbon tetrachloride of steps during the vapor-phase epitaxial growth of III­V compound semiconductors.3,4 Carbon tetrachloride

  8. Formation of copper-indium-selenide and/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

    DOE Patents [OSTI]

    Curtis, Calvin J. (Lakewood, CO); Miedaner, Alexander (Boulder, CO); Van Hest, Maikel (Lakewood, CO); Ginley, David S. (Evergreen, CO); Nekuda, Jennifer A. (Lakewood, CO)

    2011-11-15T23:59:59.000Z

    Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and/or copper indium gallium selenide films (66) on substrates (52).

  9. Atomic layer structure of manganese atoms on wurtzite gallium nitride Abhijit Chinchore, Kangkang Wang, Wenzhi Lin, Jeongihm Pak, and Arthur R. Smitha

    E-Print Network [OSTI]

    Atomic layer structure of manganese atoms on wurtzite gallium nitride ,,0001¯... Abhijit Chinchore on wurtzite GaN 0001¯ . The surface is monitored using reflection high energy electron diffraction, which to grow with an abrupt interface and well- defined epitaxial orientation on top of wurtzite w -GaN. Re

  10. Measurement of the solar neutrino capture rate with gallium metal, part III

    SciTech Connect (OSTI)

    Elliott, Steven Ray [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keY of 65.4{sup +3.1}{sub 3.0} (stat) {sup +2.6}{sub -2.8} (syst) SNU. The weighted average of the results of all three Ga solar neUlrino experiments, SAGE, Gallex, and GNO, is now 66.1 {+-} 3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced {sup 37}Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior {sup 51}Cr neutrino-source experiments with Ga, is 0.88 {+-} 0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in {sup 71}Ge has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63--67 SNU with an uncertainly of about 5%, in good agreement with experiment. We derive the current value of the pp neutrino flux produced in the Sun to be {phi}{sup {circle_dot}}{sub pp} = (6.1 {+-} 0.8) x 10{sup 10}/(cm{sup 2} s), which agrees well with the flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  11. High-performance amorphous gallium indium zinc oxide thin-film transistors through N{sub 2}O plasma passivation

    SciTech Connect (OSTI)

    Park, Jaechul; Kim, Sangwook; Kim, Changjung; Kim, Sunil; Song, Ihun; Yin, Huaxiang; Kim, Kyoung-Kok; Lee, Sunghoon; Hong, Kiha; Park, Youngsoo [Semiconductor Device Laboratory, Samsung Advanced Institute of Technology, Yongin-Si, Gyeonggi-Do 449-712 (Korea, Republic of); Lee, Jaecheol; Jung, Jaekwan; Lee, Eunha [Analytical Engineering Center, Samsung Advanced Institute of Technology, Yongin-Si, Gyeonggi-Do 449-712 (Korea, Republic of); Kwon, Kee-Won [Department of Semiconductor Systems Engineering, Sungkyunkwan University, Suwon-Si, Gyeonggi-Do 440-746 (Korea, Republic of)

    2008-08-04T23:59:59.000Z

    Amorphous-gallium-indium-zinc-oxide (a-GIZO) thin filmtransistors (TFTs) are fabricated without annealing, using processes and equipment for conventional a-Si:H TFTs. It has been very difficult to obtain sound TFT characteristics, because the a-GIZO active layer becomes conductive after dry etching the Mo source/drain electrode and depositing the a-SiO{sub 2} passivation layer. To prevent such damages, N{sub 2}O plasma is applied to the back surface of the a-GIZO channel layer before a-SiO{sub 2} deposition. N{sub 2}O plasma-treated a-GIZO TFTs exhibit excellent electrical properties: a field effect mobility of 37 cm{sup 2}/V s, a threshold voltage of 0.1 V, a subthreshold swing of 0.25 V/decade, and an I{sub on/off} ratio of 7.

  12. Compact, Interactive Electric Vehicle Charger: Gallium-Nitride Switch Technology for Bi-directional Battery-to-Grid Charger Applications

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    ADEPT Project: HRL Laboratories is using gallium nitride (GaN) semiconductors to create battery chargers for electric vehicles (EVs) that are more compact and efficient than traditional EV chargers. Reducing the size and weight of the battery charger is important because it would help improve the overall performance of the EV. GaN semiconductors process electricity faster than the silicon semiconductors used in most conventional EV battery chargers. These high-speed semiconductors can be paired with lighter-weight electrical circuit components, which helps decrease the overall weight of the EV battery charger. HRL Laboratories is combining the performance advantages of GaN semiconductors with an innovative, interactive battery-to-grid energy distribution design. This design would support 2-way power flow, enabling EV battery chargers to not only draw energy from the power grid, but also store and feed energy back into it.

  13. An experiment to test the viability of a gallium-arsenide cathode in a SRF electron gun

    SciTech Connect (OSTI)

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Wu, Q.; Todd, R.; Wang, E.; Bluem, H.; Holmes, D.; Schultheiss, T.

    2009-05-04T23:59:59.000Z

    Strained gallium arsenide cathodes are used in electron guns for the production of polarized electrons. In order to have a sufficient quantum efficiency lifetime of the cathode the vacuum in the gun must be 10{sup -11} Torr or better, so that the cathode is not destroyed by ion back bombardment or through contamination with residual gases. All successful polarized guns are DC guns, because such vacuum levels can not be obtained in normal conducting RF guns. A superconductive RF gun may provide a sufficient vacuum level due to cryo-pumping of the cavity walls. We report on the progress of our experiment to test such a gun with normal GaAs-Cs crystals.

  14. Low-temperature growth of gallium nitride films by inductively coupled-plasma-enhanced reactive magnetron sputtering

    SciTech Connect (OSTI)

    Ni, Chih-Jui; Chau-Nan Hong, Franklin, E-mail: hong@mail.ncku.edu.tw [Department of Chemical Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2014-05-15T23:59:59.000Z

    Gallium nitride (GaN) films were grown on sapphire substrate by reactive magnetron sputtering. Inductively coupled-plasma (ICP) source was installed between the substrate holder and the sputtering target to increase the plasma density and the degree of ionization of nitrogen gas. Liquid Ga and Ar/N{sub 2} were used as the sputtering target and sputtering gases, respectively. X-ray diffraction measurements confirmed that the authors could grow high quality GaN crystallites at 500?°C. However, the crystalline GaN (0002) peak remained even by lowering the growth temperature down to 300?°C. The N:Ga ratio of the film grown at 500?°C was almost 1:1, and the nitrogen composition became higher toward the 1:1 N:Ga ratio with increasing the growth temperature. The high degree of ionization induced by ICP source was essential to the growth of high crystalline quality GaN films.

  15. integrative www.unil.ch/cig

    E-Print Network [OSTI]

    Kaessmann, Henrik

    on plant growth and development 12 Paul Franken Genetics and energetics of sleep homeostasis and circadian the acquisition of new technologies or the development of new research and educational activities or services

  16. Gas source molecular beam epitaxy of scandium nitride on silicon carbide and gallium nitride surfaces

    SciTech Connect (OSTI)

    King, Sean W., E-mail: sean.king@intel.com; Davis, Robert F. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Nemanich, Robert J. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-11-01T23:59:59.000Z

    Scandium nitride (ScN) is a group IIIB transition metal nitride semiconductor with numerous potential applications in electronic and optoelectronic devices due to close lattice matching with gallium nitride (GaN). However, prior investigations of ScN have focused primarily on heteroepitaxial growth on substrates with a high lattice mismatch of 7%–20%. In this study, the authors have investigated ammonia (NH{sub 3}) gas source molecular beam epitaxy (NH{sub 3}-GSMBE) of ScN on more closely lattice matched silicon carbide (SiC) and GaN surfaces (<3% mismatch). Based on a thermodynamic analysis of the ScN phase stability window, NH{sub 3}-GSMBE conditions of 10{sup ?5}–10{sup ?4} Torr NH{sub 3} and 800–1050?°C where selected for initial investigation. In-situ x-ray photoelectron spectroscopy (XPS) and ex-situ Rutherford backscattering measurements showed all ScN films grown using these conditions were stoichiometric. For ScN growth on 3C-SiC (111)-(?3?×??3)R30° carbon rich surfaces, the observed attenuation of the XPS Si 2p and C 1s substrate core levels with increasing ScN thickness indicated growth initiated in a layer-by-layer fashion. This was consistent with scanning electron microscopy (SEM) images of 100–200?nm thick films that revealed featureless surfaces. In contrast, ScN films grown on 3C-SiC (111)-(3?×?3) and 3C-SiC (100)-(3?×?2) silicon rich surfaces were found to exhibit extremely rough surfaces in SEM. ScN films grown on both 3C-SiC (111)-(?3?×??3)R30° and 2H-GaN (0001)-(1?×?1) epilayer surfaces exhibited hexagonal (1?×?1) low energy electron diffraction patterns indicative of (111) oriented ScN. X-ray diffraction ?-2? rocking curve scans for these same films showed a large full width half maximum of 0.29° (1047?arc sec) consistent with transmission electron microscopy images that revealed the films to be poly-crystalline with columnar grains oriented at ?15° to the [0001] direction of the 6H-SiC (0001) substrate. In-situ reflection electron energy loss spectroscopy measurements determined the band-gap for the NH{sub 3}-GSMBE ScN films to be 1.5?±?0.3 eV, and thermal probe measurements indicated all ScN films to be n-type. The four point probe sheet resistance of the ScN films was observed to increase with decreasing growth temperature and decreased with unintentional oxygen incorporation. Hg probe capacitance–voltage measurements indicated N{sub D}-N{sub A} decreased with decreasing growth temperature from 10{sup 19} to 10{sup 20}/cm{sup 3} for the lowest resistivity films to ?5?×?10{sup 16}/cm{sup 3} for the highest resistivity films. In-situ ultraviolet photoelectron spectroscopy measurements additionally showed the valence band maximum moving from 1.4 to 0.8 eV below the Fermi level with decreasing growth temperature consistent with the increased resistivity and reduction in carrier concentration. These results suggest that additional reductions in ScN carrier concentrations can be achieved via continued optimization of ScN growth conditions and selection of substrate orientation and surface termination.

  17. CO{sub 2} laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements

    SciTech Connect (OSTI)

    Bamford, D. J.; Cummings, E. A.; Panasenko, D. [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States)] [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States); Fenner, D. B.; Hensley, J. M. [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States)] [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States); Boivin, R. L.; Carlstrom, T. N.; Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)] [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

    2013-09-15T23:59:59.000Z

    A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10{sup 17} m{sup ?2} in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.

  18. Photon self-induced spin-to-orbital conversion in a terbium-gallium-garnet crystal at high laser power

    SciTech Connect (OSTI)

    Mosca, S.; De Rosa, R.; Milano, L. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', Complesso Universitario di Monte S. Angelo, 80126 Napoli (Italy); INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, 80126 Napoli (Italy); Canuel, B.; Genin, E. [EGO, European Gravitational Observatory, Via E. Amaldi, 56021 S. Stefano a Macerata, Cascina (Italy); Karimi, E. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', Complesso Universitario di Monte S. Angelo, 80126 Napoli (Italy); Piccirillo, B.; Santamato, E. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', Complesso Universitario di Monte S. Angelo, 80126 Napoli (Italy); CNISM-Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Napoli (Italy); Marrucci, L. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', Complesso Universitario di Monte S. Angelo, 80126 Napoli (Italy); CNR-INFM Coherentia, Complesso Universitario di Monte S. Angelo, 80126 Napoli (Italy)

    2010-10-15T23:59:59.000Z

    In this paper, we present experimental evidence of a third-order nonlinear optical process, self-induced spin-to-orbital conversion (SISTOC) of the photon angular momentum. This effect is the physical mechanism at the origin of the depolarization of very intense laser beams propagating in isotropic materials. The SISTOC process, like self-focusing, is triggered by laser heating leading to a radial temperature gradient in the medium. In this work we tested the occurrence of SISTOC in a terbium-gallium-garnet rod for an impinging laser power of about 100 W. To study the SISTOC process we used different techniques: polarization analysis, interferometry, and tomography of the photon orbital angular momentum. Our results confirm, in particular, that the apparent depolarization of the beam is due to the occurrence of maximal entanglement between the spin and orbital angular momentum of the photons undergoing the SISTOC process. This explanation of the true nature of the depolarization mechanism could be of some help in finding novel methods to reduce or to compensate for this usually unwanted depolarization effect in all cases where very high laser power and good beam quality are required.

  19. Saddle-like deformation in a dielectric elastomer actuator embedded with liquid-phase gallium-indium electrodes

    SciTech Connect (OSTI)

    Wissman, J., E-mail: jwissman@andrew.cmu.edu [Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Finkenauer, L. [Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Deseri, L. [DICAM, Department of Mechanical, Civil and Environmental Engineering, University of Trento, via Mesiano 77 38123 Trento (Italy); TMHRI-Department of Nanomedicine, The Methodist Hospital Research Institute, 6565 Fannin St., MS B-490 Houston, Texas 77030 (United States); Mechanics, Materials and Computing Center, CEE and ME-CIT, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Majidi, C. [Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Robotics Institute and Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

    2014-10-14T23:59:59.000Z

    We introduce a dielectric elastomer actuator (DEA) composed of liquid-phase Gallium-Indium (GaIn) alloy electrodes embedded between layers of poly(dimethylsiloxane) (PDMS) and examine its mechanics using a specialized elastic shell theory. Residual stresses in the dielectric and sealing layers of PDMS cause the DEA to deform into a saddle-like geometry (Gaussian curvature K<0). Applying voltage ? to the liquid metal electrodes induces electrostatic pressure (Maxwell stress) on the dielectric and relieves some of the residual stress. This reduces the longitudinal bending curvature and corresponding angle of deflection ?. Treating the elastomer as an incompressible, isotropic, NeoHookean solid, we develop a theory based on the principle of minimum potential energy to predict the principal curvatures as a function of ?. Based on this theory, we predict a dependency of ? on ? that is in strong agreement with experimental measurements performed on a GaIn-PDMS composite. By accurately modeling electromechanical coupling in a soft-matter DEA, this theory can inform improvements in design and fabrication.

  20. Low-temperature synthesis of gallium nitride thin films using electron cyclotron resonance plasma assisted pulsed laser deposition from a GaAs target

    SciTech Connect (OSTI)

    Sun, J.; Wu, A.M.; Xu, N.; Ying, Z.F.; Shen, X.K.; Dong, Z.B.; Wu, J.D.; Shi, L.Q. [State Key Laboratory for Advanced Photonic Materials and Devices, Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2005-11-15T23:59:59.000Z

    Using reactive pulsed laser deposition assisted by electron cyclotron resonance (ECR) plasma, we have synthesized GaN thin films from a polycrystalline GaAs target at low temperatures. This was achieved by ablating the GaAs target in the reactive environment of a nitrogen plasma generated from ECR microwave discharge in pure nitrogen gas and depositing the films with concurrent bombardment by the low-energy nitrogen plasma stream. High-energy ion backscattering spectroscopy analysis shows that the synthesized films are gallium rich. Characterizations by x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy confirm the presence of GaN bonds in the films. The recorded absorption spectrum also reveals GaN stretching mode characteristic of the hexagonal GaN phase. The synthesized GaN films are transparent in the visible region and have a band gap of 3.38 eV. Optical emission from the plume during film deposition reveals that the plume created by pulsed laser ablation of the GaAs target consists mainly of monoatomic atoms and ions of gallium and arsenic. Mechanisms responsible for the formation of GaN molecules and the growth of GaN films are also discussed.

  1. Rare-earth metal gallium silicides via the gallium self-flux method. Synthesis, crystal structures, and magnetic properties of RE(Ga1–xSix)? (RE=Y, La–Nd, Sm, Gd–Yb, Lu)

    SciTech Connect (OSTI)

    Darone, Gregory M.; Hmiel, Benjamin; Zhang, Jiliang [Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716 (United States); Saha, Shanta; Kirshenbaum, Kevin; Greene, Richard; Paglione, Johnpierre [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Bobev, Svilen, E-mail: bobev@udel.edu [Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716 (United States)

    2013-05-01T23:59:59.000Z

    Fifteen ternary rare-earth metal gallium silicides have been synthesized using molten Ga as a molten flux. They have been structurally characterized by single-crystal and powder X-ray diffraction to form with three different structures—the early to mid-late rare-earth metals RE=La–Nd, Sm, Gd–Ho, Yb and Y form compounds with empirical formulae RE(GaxSi1–x)? (0.38?x?0.63), which crystallize with the tetragonal ?-ThSi? structure type (space group I4?/amd, No. 141; Pearson symbol tI12). The compounds of the late rare-earth crystallize with the orthorhombic ?-GdSi? structure type (space group Imma, No. 74; Pearson symbol oI12), with refined empirical formula REGaxSi2–x–y (RE=Ho, Er, Tm; 0.33?x?0.40, 0.10?y?0.18). LuGa?.?????Si?.????? crystallizes with the orthorhombic YbMn?.??Si?.?? structure type (space group Cmcm, No. 63; Pearson symbol oC24). Structural trends are reviewed and analyzed; the magnetic susceptibilities of the grown single-crystals are presented. - Graphical abstract: This article details the exploration of the RE–Ga–Si ternary system with the aim to systematically investigate the structural “boundaries” between the ?-ThSi? and ?-GdSi?-type structures, and studies of the magnetic properties of the newly synthesized single-crystalline materials. Highlights: • Light rare-earth gallium silicides crystallize in ?-ThSi? structure type. • Heavy rare-earth gallium silicides crystallize in ?-GdSi? structure type. • LuGaSi crystallizes in a defect variant of the YbMn?.??Si?.?? structure type.

  2. Alumina nanoparticle/polymer nanocomposite dielectric for flexible amorphous indium-gallium-zinc oxide thin film transistors on plastic substrate with superior stability

    SciTech Connect (OSTI)

    Lai, Hsin-Cheng [Department of Electrical Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Pei, Zingway, E-mail: zingway@dragon.nchu.edu.tw [Department of Electrical Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 40227, Taiwan (China); Jian, Jyun-Ruri; Tzeng, Bo-Jie [Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2014-07-21T23:59:59.000Z

    In this study, the Al{sub 2}O{sub 3} nanoparticles were incorporated into polymer as a nono-composite dielectric for used in a flexible amorphous Indium-Gallium-Zinc Oxide (a-IGZO) thin-film transistor (TFT) on a polyethylene naphthalate substrate by solution process. The process temperature was well below 100?°C. The a-IGZO TFT exhibit a mobility of 5.13?cm{sup 2}/V s on the flexible substrate. After bending at a radius of 4?mm (strain?=?1.56%) for more than 100 times, the performance of this a-IGZO TFT was nearly unchanged. In addition, the electrical characteristics are less altered after positive gate bias stress at 10?V for 1500?s. Thus, this technology is suitable for use in flexible displays.

  3. Final Technical Report: Hawaii Hydrogen Center for Development and Deployment of Distributed Energy Systems

    SciTech Connect (OSTI)

    Rocheleau, Richard E.

    2008-09-30T23:59:59.000Z

    Hydrogen power park experiments in Hawai‘i produced real-world data on the performance of commercialized electrochemical components and power systems integrating renewable and hydrogen technologies. By analyzing the different losses associated with the various equipment items involved, this work identifies the different improvements necessary to increase the viability of these technologies for commercial deployment. The stand-alone power system installed at Kahua Ranch on the Big Island of Hawaii required the development of the necessary tools to connect, manage and monitor such a system. It also helped the electrolyzer supplier to adapt its unit to the stand-alone power system application. Hydrogen fuel purity assessments conducted at the Hawai‘i Natural Energy Institute (HNEI) fuel cell test facility yielded additional knowledge regarding fuel cell performance degradation due to exposure to several different fuel contaminants. In addition, a novel fitting strategy was developed to permit accurate separation of the degradation of fuel cell performance due to fuel impurities from other losses. A specific standard MEA and a standard flow field were selected for use in future small-scale fuel cell experiments. Renewable hydrogen production research was conducted using photoelectrochemical (PEC) devices, hydrogen production from biomass, and biohydrogen analysis. PEC device activities explored novel configurations of ‘traditional’ photovoltaic materials for application in high-efficiency photoelectrolysis for solar hydrogen production. The model systems investigated involved combinations of copper-indium-gallium-diselenide (CIGS) and hydrogenated amorphous silicon (a-Si:H). A key result of this work was the establishment of a robust “three-stage” fabrication process at HNEI for high-efficiency CIGS thin film solar cells. The other key accomplishment was the development of models, designs and prototypes of novel ‘four-terminal’ devices integrating high-efficiency CIGS and a-Si:H with operating features compatible with high-efficiency photoelectrochemical (PEC) water-splitting. The objective of one activity under the hydrogen production from biomass task was to conduct parametric testing of the Pearson gasifier and to determine the effects of gasifier operating conditions on the gas yields and quality. The hydrogen yield from this gasifier was evaluated in a parametric test series over a range of residence times from 0.8 to 2.2 seconds. H2 concentrations as high as 55% (volume) were measured in the product gas at the longer residence times and this corresponds to a hydrogen yield of 90 kg per tonne of bagasse without gas upgrading. The objective of another activity was to develop hot gas clean-up capabilities for the HNEI gasifier test facility to support hydrogen-from-biomass research. The product gas stream at the outlet of the hot gas filter was characterized for concentrations of permanent gas species and contaminants. Biomass feedstock processing activity included a preliminary investigation into methods for processing sugar cane trash at the Puunene Sugar Factory on the island of Maui, Hawaii. The objective of the investigation was to explore treatment methods that would enable the successful use of cane trash as fuel for the production of hydrogen via gasification. Analyses were completed for the technical and economic feasibility of producing biofuel from photosynthetic marine microbes on a commercial scale. Results included estimates for total costs, energy efficiency, and return on investment. The biohydrogen team undertook a comprehensive review of the field and came to what is considered a realistic conclusion. To summarize, continued research is recommended in the fundamentals of the science related to genetic engineering and specific topics to cover knowledge gaps. In the meantime, the team also advocates continued development of related processes which can be linked to pollution control and other real world applications. The extra revenues hydrogen can provide to these multi-product systems can

  4. COMMUNICATION www.MaterialsViews.com

    E-Print Network [OSTI]

    A, Weinheim (1 of 7) 1301916wileyonlinelibrary.com Improved Cu2O-Based Solar Cells Using Atomic Layer cell materials including copper indium gallium selenide (CIGS).[16] In the past, chemical treatments in enhancements of solar cell performance.[5,7,18] However, even if the surface treatments remove the CuO layer

  5. CX-002541: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Emerging Renewables Industries: Copper, Indium, Gallium, Selenium (CIGS) Linear Source Thermal DepositionCX(s) Applied: B2.2, B5.1Date: 05/19/2010Location(s): St. Paul, MinnesotaOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

  6. Gallium interactions with Zircaloy

    E-Print Network [OSTI]

    West, Michael Keith

    1998-01-01T23:59:59.000Z

    -nitride insulated cylinder wrapped with a tantalum oven wire and provides for evaporation of solid source materials. For an appropriate combination of gas pressure, filament current, and anode voltage, a plasma is formed in the hollow cathode region of the source... of the goniometer motor above 100 'C. In addition, braided copper straps were wrapped around the goniometer motors and connected to the cold plates in the target chamber. Zirc-4 Target Heater Wire Current = 2. 5 A To Current Integrator Inner Cup Bias = -200...

  7. Gallium interactions with Zircaloy 

    E-Print Network [OSTI]

    West, Michael Keith

    1998-01-01T23:59:59.000Z

    with Rutherford backscattering and SIMS techniques. Results indicate that the Zirc-4 is little affected up to a fluency of [] Ga ions/[]. After implantation of [] Ga ions/[], sub-grain features on the order of 2 gm were observed which may be due to intermetallic...

  8. Indium and gallium oxynitrides prepared in the presence of Zn{sup 2+} by ammonolysis of the oxide precursors obtained via the citrate route

    SciTech Connect (OSTI)

    Miyaake, Azumi; Masubuchi, Yuji; Takeda, Takashi [Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan)] [Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan); Kikkawa, Shinichi, E-mail: kikkawa@eng.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan)] [Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan)

    2010-04-15T23:59:59.000Z

    Ammonia nitridation of indium and gallium oxide precursors obtained through a soft solution route led to their oxynitrides [In{sub 0.97}{open_square}{sub 0.03}][N{sub 0.92}O{sub 0.08}] at 660 {sup o}C and [Ga{sub 0.89}{open_square}{sub 0.11}][N{sub 0.66}O{sub 0.34}] at 850 {sup o}C, respectively, where {open_square} refers to a In or Ga vacancy. Cation vacancies in their wurtzite-type lattice were eliminated in similar preparations with the co-presence of Zn{sup 2+} by forming complete solid solutions of (InN){sub 1-x}(ZnO){sub x} and (GaN){sub 1-y}(ZnO){sub y}. The optical absorption edge shape was found to be relatively steep at the solid solution limits of x {approx} 0.23 and y {approx} 0.33 compared to the case without zinc.

  9. Photovoltaic Materials

    SciTech Connect (OSTI)

    Duty, C.; Angelini, J.; Armstrong, B.; Bennett, C.; Evans, B.; Jellison, G. E.; Joshi, P.; List, F.; Paranthaman, P.; Parish, C.; Wereszczak, A.

    2012-10-15T23:59:59.000Z

    The goal of the current project was to help make the US solar industry a world leader in the manufacture of thin film photovoltaics. The overall approach was to leverage ORNL’s unique characterization and processing technologies to gain a better understanding of the fundamental challenges for solar cell processing and apply that knowledge to targeted projects with industry members. ORNL has the capabilities in place and the expertise required to understand how basic material properties including defects, impurities, and grain boundaries affect the solar cell performance. ORNL also has unique processing capabilities to optimize the manufacturing process for fabrication of high efficiency and low cost solar cells. ORNL recently established the Center for Advanced Thin-film Systems (CATS), which contains a suite of optical and electrical characterization equipment specifically focused on solar cell research. Under this project, ORNL made these facilities available to industrial partners who were interested in pursuing collaborative research toward the improvement of their product or manufacturing process. Four specific projects were pursued with industrial partners: Global Solar Energy is a solar industry leader in full scale production manufacturing highly-efficient Copper Indium Gallium diSelenide (CIGS) thin film solar material, cells and products. ORNL worked with GSE to develop a scalable, non-vacuum, solution technique to deposit amorphous or nanocrystalline conducting barrier layers on untextured stainless steel substrates for fabricating high efficiency flexible CIGS PV. Ferro Corporation’s Electronic, Color and Glass Materials (“ECGM”) business unit is currently the world’s largest supplier of metallic contact materials in the crystalline solar cell marketplace. Ferro’s ECGM business unit has been the world's leading supplier of thick film metal pastes to the crystalline silicon PV industry for more than 30 years, and has had operational cells and modules in the field for 25 years. Under this project, Ferro leveraged world leading analytical capabilities at ORNL to characterize the paste-to-silicon interface microstructure and develop high efficiency next generation contact pastes. Ampulse Corporation is developing a revolutionary crystalline-silicon (c-Si) thin-film solar photovoltaic (PV) technology. Utilizing uniquely-textured substrates and buffer materials from the Oak Ridge National Laboratory (ORNL), and breakthroughs in Hot-Wire Chemical Vapor Deposition (HW-CVD) techniques in epitaxial silicon developed at the National Renewable Energy Laboratory (NREL), Ampulse is creating a solar technology that is tunable in silicon thickness, and hence in efficiency and economics, to meet the specific requirements of multiple solar PV applications. This project focused on the development of a high rate deposition process to deposit Si, Ge, and Si1-xGex films as an alternate to hot-wire CVD. Mossey Creek Solar is a start-up company with great expertise in the solar field. The primary interest is to create and preserve jobs in the solar sector by developing high-yield, low-cost, high-efficiency solar cells using MSC-patented and -proprietary technologies. The specific goal of this project was to produce large grain formation in thin, net-shape-thickness mc-Si wafers processed with high-purity silicon powder and ORNL's plasma arc lamp melting without introducing impurities that compromise absorption coefficient and carrier lifetime. As part of this project, ORNL also added specific pieces of equipment to enhance our ability to provide unique insight for the solar industry. These capabilities include a moisture barrier measurement system, a combined physical vapor deposition and sputtering system dedicated to cadmium-containing deposits, adeep level transient spectroscopy system useful for identifying defects, an integrating sphere photoluminescence system, and a high-speed ink jet printing system. These tools were combined with others to study the effect of defects on the performance of crystalline silicon and

  10. Measurement of the solar neutrino capture rate with gallium metal. III. Results for the 2002-2007 data-taking period

    SciTech Connect (OSTI)

    Abdurashitov, J. N.; Gavrin, V. N.; Gorbachev, V. V.; Gurkina, P. P.; Ibragimova, T. V.; Kalikhov, A. V.; Khairnasov, N. G.; Knodel, T. V.; Mirmov, I. N.; Shikhin, A. A.; Veretenkin, E. P.; Yants, V. E.; Zatsepin, G. T.; Bowles, T. J.; Elliott, S. R.; Teasdale, W. A.; Nico, J. S.; Cleveland, B. T.; Wilkerson, J. F. [Institute for Nuclear Research, Russian Academy of Sciences, RU-117312 Moscow (Russian Federation); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); National Institute of Standards and Technology, Stop 8461, Gaithersburg, Maryland 20899 (United States); University of Washington, Seattle, Washington 98195 (United States)

    2009-07-15T23:59:59.000Z

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keV of 65.4{sub -3.0}{sup +3.1} (stat) {sub -2.8}{sup +2.6} (syst) SNU. The weighted average of the results of all three Ga solar neutrino experiments, SAGE, Gallex, and GNO, is now 66.1{+-}3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced {sup 37}Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior {sup 51}Cr neutrino-source experiments with Ga, is 0.87{+-}0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in {sup 71}Ge has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63 SNU to 66 SNU with an uncertainty of about 4%, in good agreement with experiment. We derive the current value of the neutrino flux produced in the Sun by the proton-proton fusion reaction to be {phi}{sub pp}{sup {center_dot}}=(6.0{+-}0.8)x10{sup 10}/(cm{sup 2} s), which agrees well with the pp flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  11. Measurement of the solar neutrino capture rate with gallium metal. III: Results for the 2002--2007 data-taking period

    E-Print Network [OSTI]

    SAGE Collaboration; J. N. Abdurashitov; V. N. Gavrin; V. V. Gorbachev; P. P. Gurkina; T. V. Ibragimova; A. V. Kalikhov; N. G. Khairnasov; T. V. Knodel; I. N. Mirmov; A. A. Shikhin; E. P. Veretenkin; V. E. Yants; G. T. Zatsepin; T. J. Bowles; S. R. Elliott; W. A. Teasdale; J. S. Nico; B. T. Cleveland; J. F. Wilkerson

    2009-08-10T23:59:59.000Z

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in Dec. 1989. Measurements have continued with only a few brief interruptions since that time. We give here the experimental improvements in SAGE since its last published data summary in Dec. 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through Dec. 2007 gives a capture rate of solar neutrinos with energy more than 233 keV of 65.4 (+3.1)(-3.0) (stat) (+2.6)(-2.8) (syst) SNU. The weighted average of the results of all three Ga solar neutrino experiments, SAGE, Gallex, and GNO, is now 66.1 +/- 3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced 37Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior 51Cr neutrino-source experiments with Ga, is 0.87 +/- 0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in 71Ge has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63-66 SNU with an uncertainty of about 4%, in good agreement with experiment. We derive the current value of the neutrino flux produced in the Sun by the proton-proton fusion reaction to be (6.0 +/- 0.8) x 10^(10)/(cm^2 s), which agrees well with the pp flux predicted by the standard solar model. Finally, we show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  12. SOLAR SEMINAR SERIES S P R I N G 2 0 1 3 P H O T O V O L T A I C S E M I N A R S E R I E S

    E-Print Network [OSTI]

    Ginzel, Matthew

    challenge for the success of copper indium gallium selenide (CIGS) photovoltaic cells. Co-evaporation yieldsSOLAR SEMINAR SERIES S P R I N G 2 0 1 3 P H O T O V O L T A I C S E M I N A R S E R I E S BILLY J spanning more than 30 years in the solar industry. He is an expert in the business and science

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

    E-Print Network [OSTI]

    Sites, James R.

    80523 ABSTRACT Copper indium gallium sulfide, CuIn1-xGaxS2 (CIGS2) solar cells prepared with chemicalCuIn1-xGaxS2 thin film solar cells with ZnxCd1-xS as heterojunction partner Bhaskar Kumar 1 , Parag/heterojunction partner/ ZnO/Cr/Ag contact fingers solar cells of area ~0.44 cm 2 were fabricated at FSEC

  14. Sandia National Laboratories: gallium nitride

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

    and Systems Dept.) recently published the article "Band offsets of La2O3 on (0001) GaN grown by reactive molecular-beam epitaxy" in Applied Physics Letters outlining research...

  15. Improvement of bias-stability in amorphous-indium-gallium-zinc-oxide thin-film transistors by using solution-processed Y{sub 2}O{sub 3} passivation

    SciTech Connect (OSTI)

    An, Sungjin; Mativenga, Mallory; Kim, Youngoo; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center, Department of Information Display, Kyung Hee University, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2014-08-04T23:59:59.000Z

    We demonstrate back channel improvement of back-channel-etch amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors by using solution-processed yttrium oxide (Y{sub 2}O{sub 3}) passivation. Two different solvents, which are acetonitrile (35%)?+?ethylene glycol (65%), solvent A and deionized water, solvent B are investigated for the spin-on process of the Y{sub 2}O{sub 3} passivation—performed after patterning source/drain (S/D) Mo electrodes by a conventional HNO{sub 3}-based wet-etch process. Both solvents yield devices with good performance but those passivated by using solvent B exhibit better light and bias stability. Presence of yttrium at the a-IGZO back interface, where it occupies metal vacancy sites, is confirmed by X-ray photoelectron spectroscopy. The passivation effect of yttrium is more significant when solvent A is used because of the existence of more metal vacancies, given that the alcohol (65% ethylene glycol) in solvent A may dissolve the metal oxide (a-IGZO) through the formation of alkoxides and water.

  16. Preparation of cuxinygazsen (X=0-2, Y=0-2, Z=0-2, N=0-3) precursor films by electrodeposition for fabricating high efficiency solar cells

    DOE Patents [OSTI]

    Bhattacharya, Raghu N. (Littleton, CO); Contreras, Miguel A. (Golden, CO); Keane, James (Lakewood, CO); Tennant, Andrew L. (Denver, CO); Tuttle, John R. (Denver, CO); Ramanathan, Kannan (Lakewood, CO); Noufi, Rommel (Golden, CO)

    1998-03-24T23:59:59.000Z

    High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

  17. Direct measurements of band gap grading in polycrystalline CIGS solar cells

    E-Print Network [OSTI]

    Heinrich, M P; Zhang, Y; Kiowski, O; Powalla, M; Lemmer, U; Slobodskyy, A

    2010-01-01T23:59:59.000Z

    We present direct measurements of depth-resolved band gap variations of CuIn(1-x)Ga(x)Se2 thin-film solar cell absorbers. A new measurement technique combining parallel measurements of local thin-film interference and spectral photoluminescence was developed for this purpose. We find sample-dependent correlation parameters between measured band gap depth and composition profiles, and emphasize the importance of direct measurements. These results bring a quantitative insight into the electronic properties of the solar cells and open a new way to analyze parameters that determine the efficiency of solar cells.

  18. Post-Deposition Treatment Boosts CIGS Solar Cell Performance (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-08-01T23:59:59.000Z

    NREL's use of potassium fluoride process improves the open-circuit voltage and conversion efficiency.

  19. Direct measurements of band gap grading in polycrystalline CIGS solar cells

    E-Print Network [OSTI]

    M. P. Heinrich; Z-H. Zhang; Y. Zhang; O. Kiowski; M. Powalla; U. Lemmer; A. Slobodskyy

    2010-09-20T23:59:59.000Z

    We present direct measurements of depth-resolved band gap variations of CuIn(1-x)Ga(x)Se2 thin-film solar cell absorbers. A new measurement technique combining parallel measurements of local thin-film interference and spectral photoluminescence was developed for this purpose. We find sample-dependent correlation parameters between measured band gap depth and composition profiles, and emphasize the importance of direct measurements. These results bring a quantitative insight into the electronic properties of the solar cells and open a new way to analyze parameters that determine the efficiency of solar cells.

  20. CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and Accomplishments

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR57451 Clean Energy Technologies A

  1. NREL: Awards and Honors - Lightweight, Flexible, Thin-Film CIGS PV Modules

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Saleshttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifNREL NREL Refines MethodLightweight, Flexible, Thin-Film

  2. Statistical Methods for Enhanced Metrology in Semiconductor/Photovoltaic Manufacturing

    E-Print Network [OSTI]

    Zeng, Dekong

    2012-01-01T23:59:59.000Z

    VACUUM PROCESSING OF CIGS SOLAR CELLS ON FLEXIBLE POLYMERICcell………………………… Figure 2.5 CIGS based solar cell fabricationcells. Figure 2.5 CIGS based solar cell fabrication flow [

  3. The Effects of Non-Uniform Electronic Properties on Thin Film Photovoltaics

    E-Print Network [OSTI]

    Brown, Gregory Ferguson

    2011-01-01T23:59:59.000Z

    material   systems.   CIGS  solar  cells  grown  at  the  the  depth  of  the  CIGS  solar  cells  improve  carrier  length  in  CIGS  solar  cells  has  no  correlation  with  

  4. Self- and zinc diffusion in gallium antimonide

    E-Print Network [OSTI]

    Nicols, Samuel Piers

    2002-01-01T23:59:59.000Z

    5, 265 (1957). S. Glasstone, K . Laidler, H . Eyring, Thequantity D . Henry Eyring [Glasstone, Eyring (1941)] was the

  5. Superconductive silicon nanowires using gallium beam lithography.

    SciTech Connect (OSTI)

    Henry, Michael David; Jarecki, Robert Leo,

    2014-01-01T23:59:59.000Z

    This work was an early career LDRD investigating the idea of using a focused ion beam (FIB) to implant Ga into silicon to create embedded nanowires and/or fully suspended nanowires. The embedded Ga nanowires demonstrated electrical resistivity of 5 m-cm, conductivity down to 4 K, and acts as an Ohmic silicon contact. The suspended nanowires achieved dimensions down to 20 nm x 30 nm x 10 m with large sensitivity to pressure. These structures then performed well as Pirani gauges. Sputtered niobium was also developed in this research for use as a superconductive coating on the nanowire. Oxidation characteristics of Nb were detailed and a technique to place the Nb under tensile stress resulted in the Nb resisting bulk atmospheric oxidation for up to years.

  6. Electronic properties of gallium nitride nanowires

    E-Print Network [OSTI]

    Yoon, Joonah

    2008-01-01T23:59:59.000Z

    This thesis presents a systematic study of the electrical transport in GaN nanowires. Particularly, the effect of the surrounding dielectric on the conductivity of GaN nanowires is experimentally shown for the first time. ...

  7. Efficient wireless charging with gallium nitride FETs

    E-Print Network [OSTI]

    Yeh, Theresa (Theresa I.)

    2014-01-01T23:59:59.000Z

    Though wireless charging is more convenient than traditional wired charging methods, it is currently less efficient. This not only wastes power but can also result in a longer charging time. Improving the efficiency of ...

  8. Interactions of gallium with zircaloy cladding

    E-Print Network [OSTI]

    Mitchell, Lee Josey

    1999-01-01T23:59:59.000Z

    like to thank Dr. Ron R. Hart, my advisor, for his help and direction through out the project. I would like to acknowledge J. Shipp for his help during the RBS analysis. I would also like to thank Dr. R. Guillemette for his help with the Electron... CHAPTER I INTRODUCTION The accepted options for the disposition of weapons-grade plutonium (WGPu) are immobilization or conversion to a mixed-oxide (MOX) reactor fuel. There are two benefits of conversion, one, the plutonium can't be converted back...

  9. Smooth cubic commensurate oxides on gallium nitride

    SciTech Connect (OSTI)

    Paisley, Elizabeth A.; Gaddy, Benjamin E.; LeBeau, James M.; Shelton, Christopher T.; Losego, Mark D.; Mita, Seiji; Collazo, Ramón; Sitar, Zlatko; Irving, Douglas L.; Maria, Jon-Paul, E-mail: jpmaria@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Biegalski, Michael D.; Christen, Hans M. [Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-02-14T23:59:59.000Z

    Smooth, commensurate alloys of ?111?-oriented Mg{sub 0.52}Ca{sub 0.48}O (MCO) thin films are demonstrated on Ga-polar, c+ [0001]-oriented GaN by surfactant-assisted molecular beam epitaxy and pulsed laser deposition. These are unique examples of coherent cubic oxide|nitride interfaces with structural and morphological perfection. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100× reduction in leakage current density for the surfactant-assisted samples. HAADF-STEM images of the MCO|GaN interface show commensurate alignment of atomic planes with minimal defects due to lattice mismatch. STEM and DFT calculations show that GaN c/2 steps create incoherent boundaries in MCO over layers which manifest as two in-plane rotations and determine consequently the density of structural defects in otherwise coherent MCO. This new understanding of interfacial steps between HCP and FCC crystals identifies the steps needed to create globally defect-free heterostructures.

  10. Development of gallium nitride power transistors

    E-Print Network [OSTI]

    Piedra, Daniel, M. Eng. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    GaN-based high-voltage transistors have outstanding properties for the development of ultra-high efficiency and compact power electronics. This thesis describes a new process technology for the fabrication of GaN power ...

  11. Absorptivity of semiconductors used in the production of solar cell panels

    SciTech Connect (OSTI)

    Kosyachenko, L. A., E-mail: lakos@chv.ukrpack.net; Grushko, E. V.; Mikityuk, T. I. [Chernivtsy National University (Ukraine)

    2012-04-15T23:59:59.000Z

    The dependence of the absorptivity of semiconductors on the thickness of the absorbing layer is studied for crystalline silicon (c-Si), amorphous silicon (a-Si), cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS), and copper gallium diselenide (CuGaSe{sub 2}, CGS). The calculations are performed with consideration for the spectral distribution of AM1.5 standard solar radiation and the absorption coefficients of the materials. It is shown that, in the region of wavelengths {lambda} = {lambda}{sub g} = hc/E{sub g}, almost total absorption of the photons in AM1.5 solar radiation is attained in c-Si at the thickness d = 7-8 mm, in a-Si at d = 30-60 {mu}m, in CdTe at d = 20-30 {mu}m, and in CIS and CGS at d = 3-4 {mu}m. The results differ from previously reported data for these materials (especially for c-Si). In previous publications, the thickness needed for the semiconductor to absorb solar radiation completely was identified with the effective light penetration depth at a certain wavelength in the region of fundamental absorption for the semiconductor.

  12. Three approaches to economical photovoltaics: conformal Cu2S, organic luminescent films, and PbSe nanocrystal superlattices

    E-Print Network [OSTI]

    Carbone, Ian Anthony

    2013-01-01T23:59:59.000Z

    oxygen and water. Conventional CIGS solar cells must also bereal possibility. CIGS solar cells suffer similar parasitic

  13. Metals Production Requirements for Rapid Photovoltaics Deployment

    E-Print Network [OSTI]

    Kavlak, Goksin; Jaffe, Robert L; Trancik, Jessika E

    2015-01-01T23:59:59.000Z

    If global photovoltaics (PV) deployment grows rapidly, the required input materials need to be supplied at an increasing rate. In this paper, we quantify the effect of PV deployment levels on the scale of metals production. For example, we find that if cadmium telluride {copper indium gallium diselenide} PV accounts for more than 3% {10%} of electricity generation by 2030, the required growth rates for the production of indium and tellurium would exceed historically-observed production growth rates for a large set of metals. In contrast, even if crystalline silicon PV supplies all electricity in 2030, the required silicon production growth rate would fall within the historical range. More generally, this paper highlights possible constraints to the rate of scaling up metals production for some PV technologies, and outlines an approach to assessing projected metals growth requirements against an ensemble of past growth rates from across the metals production sector. The framework developed in this paper may be...

  14. NREL photovoltaic subcontract reports: Abstracts and document control information, 1 August 1991--31 July 1992

    SciTech Connect (OSTI)

    Not Available

    1992-08-01T23:59:59.000Z

    This report contains document control information and abstracts for the National Renewable Energy Laboratory (NREL) subcontracted photovoltaic program publications. It also lists source information on additional publications that describe US Department of Energy (DOE) PV research activities. It is not totally exhaustive, so it lists NREL contacts for requesting further information on the DOE and NREL PV programs. This report covers the period from August 1, 1991, through July 31, 1992. The purpose of continuing this type of publication is to help people keep abreast of specific PV interests, while maintaining a balance on the costs to the PV program. The information in this report is organized under PV technology areas: Amorphous silicon research; polycrystalline thin films (including copper indium diselenide, cadmium telluride, and thin-film silicon); crystalline materials and advanced concepts (including silicon, gallium arsenide, and other group III-V materials); and PV manufacturing technology development (which may include manufacturing information for various types of PV materials).

  15. Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics

    E-Print Network [OSTI]

    Eisenberg, DA; Yu, M; Lam, CW; Ogunseitan, OA; Schoenung, JM

    2013-01-01T23:59:59.000Z

    nickel alloy Titanium Polyimide Flexible polymers Notes:hazard substrate material is: polyimide. The only metal backdioxide Molybdenum Polyimide Notes: This is a subset of all

  16. High Efficiency CdTe and CIGS Thin Film Solar Cells: Highlights of the Technologies Challenges (Presentation)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR57451DOE/SC0002390dVandHEATINGDOBEH -0454

  17. Structural Integration of Silicon Solar Cells and Lithium-ion Batteries Using Printed Electronics

    E-Print Network [OSTI]

    Kang, Jin Sung

    2012-01-01T23:59:59.000Z

    better mechanical durability. CIGS solar cell has about 20%5]. However, CIGS solar cells degrade with humidity andSelenide (CIGS)[3] and organic polymer[4] solar cells are

  18. Laser Induced Breakdown Spectroscopy and Applications Toward Thin Film Analysis

    E-Print Network [OSTI]

    Owens, Travis Nathan

    2011-01-01T23:59:59.000Z

    of CIGS solar cells . Conclusions . . . . . . . . . . . . .roll-to-roll printed CIGS solar cell on aluminum substrateDepth profiling of CIGS solar cell using a nanosecond Nd:YAG

  19. Femtosecond laser processing of photovoltaic and transparent materials

    E-Print Network [OSTI]

    Ahn, Sanghoon

    2013-01-01T23:59:59.000Z

    of   'ink   based'   CIGS   solar   cells/modules.    Ink-­?based'   CIGS   solar   cells   on   lightweight  Figure 4-2. Ink-based CIGS solar cell, cross section by

  20. Creating CZTS Thin Films Via Stacked Metallic CVD and Sulfurization

    E-Print Network [OSTI]

    Bielecki, Anthony

    2013-01-01T23:59:59.000Z

    film solar cells. CIGS solar cell efficiencies have beenCIGS, making it a favorable choice for thin-film solar cells.thin film solar cell [3]. However, use of CIGS has a number

  1. Molecular solution processing of metal chalcogenide thin film solar cells

    E-Print Network [OSTI]

    Yang, Wenbing

    2013-01-01T23:59:59.000Z

    3-6,3-7] Chalcopyrite CIGS solar cells, without introducingperformance CISS and CIGS solar cells with efficiencies uptellurium might impede CIGS/CdTe solar cells from reaching

  2. Selective Chemistry of Metal Oxide Atomic Layer Deposition on Si Based Substrate Surfaces

    E-Print Network [OSTI]

    Guo, Lei

    2015-01-01T23:59:59.000Z

    of the solar cells. In CIGS solar cells, the buffer layers,encapsulation of CIGS and OPV solar cells[24, 25], barrierof flexible CIGS and OPV solar cells, robust, transparent

  3. Fully Solution-Processed Copper Chalcopyrite Thin Film Solar Cells: Materials Chemistry, Processing, and Device Physics

    E-Print Network [OSTI]

    Chung, Choong-Heui

    2012-01-01T23:59:59.000Z

    cm 2 ) efficiency CIGS solar cells taken from reference [and 20.3% efficiency CIGS solar cells [6] through the use ofcm 2 ) efficiency CIGS solar cells taken from reference [6].

  4. Morphology Control of Layer-Structured Gallium Selenide Nanowires

    E-Print Network [OSTI]

    Cui, Yi

    for stable photocathodes and battery electrodes. We report the controlled synthesis and characterization cells3 and solid-state batteries.4 Their one-dimensional nanowire (NW) structures may afford better

  5. Electronic Transport Characteristics of Gallium Nitride Nanowire-based Nanocircuits

    E-Print Network [OSTI]

    Ayres, Virginia

    . The measurements indicate a working field effect transistor utilizing a global back gate configuration. Very high and drain contacts were patterned using electron beam lithography, with Ti/Au used for the conducting source and drain material. The backside of the wafer was stripped of silicon dioxide using hydrofluoric acid and Ti

  6. Neutron irradiation effects on metal-gallium nitride contacts

    SciTech Connect (OSTI)

    Katz, Evan J.; Lin, Chung-Han; Zhang, Zhichun [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Qiu, Jie; Cao, Lei [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Mishra, Umesh K. [Departments of Electrical and Computer Engineering and Materials Science and Engineering University of California, Santa Barbara, California 93106 (United States); Brillson, Leonard J., E-mail: brillson.1@osu.edu [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Physics and Center for Materials Research, The Ohio State University, Columbus, Ohio 43210 (United States)

    2014-03-28T23:59:59.000Z

    We have measured the effect of fast and thermal neutrons on GaN Schottky barriers and ohmic contacts using current–voltage and transmission line method electrical techniques, optical, atomic force and scanning electron microscopy morphological techniques, and X-ray photoemission spectroscopy chemical techniques. These studies reveal a 10{sup 15}?n/cm{sup 2} neutron threshold for Schottky barrier ideality factor increases, a 10{sup 15}?n/cm{sup 2} fast plus thermal neutron threshold for ohmic contact sheet and contact resistance increases, and 10{sup 16}?n/cm{sup 2} neutron fluence threshold for major device degradation identified with thermally driven diffusion of Ga and N into the metal contacts and surface phase changes. These results demonstrate the need for protecting metal-GaN contacts in device applications subject to neutron radiation.

  7. Neutron irradiation effects on gallium nitride-based Schottky diodes

    SciTech Connect (OSTI)

    Lin, Chung-Han; Katz, Evan J.; Zhang, Zhichun [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States)] [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States); Qiu, Jie; Cao, Lei [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)] [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Mishra, Umesh K. [Departments of Electrical and Computer Engineering and Materials Science and Engineering, University of California, Santa Barbara, California 93106 (United States)] [Departments of Electrical and Computer Engineering and Materials Science and Engineering, University of California, Santa Barbara, California 93106 (United States); Brillson, Leonard J. [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States) [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States); Department of Physics and Center for Materials Research, The Ohio State University, Columbus, Ohio 43210 (United States)

    2013-10-14T23:59:59.000Z

    Depth-resolved cathodoluminescence spectroscopy (DRCLS), time-resolved surface photovoltage spectroscopy, X-ray photoemission spectroscopy (XPS), and current-voltage measurements together show that fast versus thermal neutrons differ strongly in their electronic and morphological effects on metal-GaN Schottky diodes. Fast and thermal neutrons introduce GaN displacement damage and native point defects, while thermal neutrons also drive metallurgical reactions at metal/GaN interfaces. Defect densities exhibit a threshold neutron fluence below which thermal neutrons preferentially heal versus create new native point defects. Scanning XPS and DRCLS reveal strong fluence- and metal-dependent electronic and chemical changes near the free surface and metal interfaces that impact diode properties.

  8. Superconductivity in gallium-substituted Ba8Si46 clathrates

    E-Print Network [OSTI]

    Li, Yang; Zhang, Ruihong; Liu, Yang; Chen, Ning; Luo, Z. P.; Ma, Xingqiao; Cao, Guohui; Feng, Z. S.; Hu, Chia-Ren; Ross, Joseph H., Jr.

    2007-01-01T23:59:59.000Z

    superconductor, with an onset at T-C approximate to 3.3 K. For x=10 and higher, no superconductivity was observed down to T=1.8 K. This represents a strong suppression of superconductivity with increasing Ga content, compared to Ba8Si46 with T-C approximate to 8...

  9. Production of gallium-66, a positron emitting nuclide for radioimmunotherapy

    SciTech Connect (OSTI)

    Mirzadeh, S. (Oak Ridge National Lab., TN (United States)); Chu, Y.Y. (Brookhaven National Lab., Upton, NY (United States))

    1991-01-01T23:59:59.000Z

    Excitation functions for production of {sup 66}Ga via {alpha}-induced nuclear reactions on enriched {sup 66}Zn and {sup 64}Zn have been measured with E{sub {alpha}}{le}27.3 MeV and E{sub {alpha}}{le}43.7 MeV employing the stack-thin target technique. In addition, the induced activity of {sup 67} Ga in the same sets of targets allowed an evaluation of the excitation functions of the corresponding nuclear reactions.

  10. Production of gallium-66, positron emitting nuclide for radioimmumotherapy

    SciTech Connect (OSTI)

    Mirzadeh, S. (Oak Ridge National Lab., TN (USA)); Chu, Yung Yee (Brookhaven National Lab., Upton, NY (USA))

    1991-01-01T23:59:59.000Z

    Excitation functions for production of {sup 66}Ga via {alpha}-induced nuclear reactions on enriched {sup 66}Zn have been measured with E{sub {alpha}}{le}27.3 MeV and E{sub {alpha}}{le}43.7 MeV employing the stack-thin target technique. In addition, the induced activity of {sup 67}Ga in the same sets of targets allowed an evaluation of the excitation functions of the corresponding nuclear reactions. 17 refs., 2 figs., 2 tabs.

  11. Production of gallium-66, a positron emitting nuclide for radioimmunotherapy

    SciTech Connect (OSTI)

    Mirzadeh, S. [Oak Ridge National Lab., TN (United States); Chu, Y.Y. [Brookhaven National Lab., Upton, NY (United States)

    1991-12-31T23:59:59.000Z

    Excitation functions for production of {sup 66}Ga via {alpha}-induced nuclear reactions on enriched {sup 66}Zn and {sup 64}Zn have been measured with E{sub {alpha}}{le}27.3 MeV and E{sub {alpha}}{le}43.7 MeV employing the stack-thin target technique. In addition, the induced activity of {sup 67} Ga in the same sets of targets allowed an evaluation of the excitation functions of the corresponding nuclear reactions.

  12. Advanced Epi Tools for Gallium Nitride Light Emitting Diode Devices

    SciTech Connect (OSTI)

    Patibandla, Nag; Agrawal, Vivek

    2012-12-01T23:59:59.000Z

    Over the course of this program, Applied Materials, Inc., with generous support from the United States Department of Energy, developed a world-class three chamber III-Nitride epi cluster tool for low-cost, high volume GaN growth for the solid state lighting industry. One of the major achievements of the program was to design, build, and demonstrate the world’s largest wafer capacity HVPE chamber suitable for repeatable high volume III-Nitride template and device manufacturing. Applied Materials’ experience in developing deposition chambers for the silicon chip industry over many decades resulted in many orders of magnitude reductions in the price of transistors. That experience and understanding was used in developing this GaN epi deposition tool. The multi-chamber approach, which continues to be unique in the ability of the each chamber to deposit a section of the full device structure, unlike other cluster tools, allows for extreme flexibility in the manufacturing process. This robust architecture is suitable for not just the LED industry, but GaN power devices as well, both horizontal and vertical designs. The new HVPE technology developed allows GaN to be grown at a rate unheard of with MOCVD, up to 20x the typical MOCVD rates of 3{micro}m per hour, with bulk crystal quality better than the highest-quality commercial GaN films grown by MOCVD at a much cheaper overall cost. This is a unique development as the HVPE process has been known for decades, but never successfully commercially developed for high volume manufacturing. This research shows the potential of the first commercial-grade HVPE chamber, an elusive goal for III-V researchers and those wanting to capitalize on the promise of HVPE. Additionally, in the course of this program, Applied Materials built two MOCVD chambers, in addition to the HVPE chamber, and a robot that moves wafers between them. The MOCVD chambers demonstrated industry-leading wavelength yield for GaN based LED wafers and industry-leading uptime enabled in part by a novel in-situ cleaning process developed in this program.

  13. Superconductivity in gallium-substituted Ba8Si46 clathrates 

    E-Print Network [OSTI]

    Li, Yang; Zhang, Ruihong; Liu, Yang; Chen, Ning; Luo, Z. P.; Ma, Xingqiao; Cao, Guohui; Feng, Z. S.; Hu, Chia-Ren; Ross, Joseph H., Jr.

    2007-01-01T23:59:59.000Z

    superconductor, with an onset at T-C approximate to 3.3 K. For x=10 and higher, no superconductivity was observed down to T=1.8 K. This represents a strong suppression of superconductivity with increasing Ga content, compared to Ba8Si46 with T-C approximate to 8...

  14. Rutherford backscattering analysis of gallium implanted 316 stainless steel 

    E-Print Network [OSTI]

    Ortensi, Javier

    2000-01-01T23:59:59.000Z

    Ion implantation of Ga ions into 316 stainless steel was performed at fluences ranging from 8x10¹? to 10¹? ions/cm². The depth profile of Ga in the steel was analyzed via Rutherford Backscattering and ToFSIMS. The surface effects were...

  15. Strongly localized excitons in gallium nitride C. Wetzel,a)

    E-Print Network [OSTI]

    Wetzel, Christian M.

    report on strong excitonic luminescence in wurtzite GaN at 3.309 and 3.365 eV T 6 K . These lines lie and characterization of excitonic luminescence transitions in wurtzite GaN about 150 meV below the fundamental elec transitions at 3.309 and 3.365 eV. Wurtzite GaN epilayers were grown by a high tempera- ture vapor phase

  16. GALLIUM--1997 29.1 By Deborah A. Kramer

    E-Print Network [OSTI]

    players. They also are used in short-range fiber optic communications systems, satellite communicationsAs is manufactured into optoelectronic devices (LED's, laser diodes, photodetectors, and solar cells) and integrated energy to a coherent light output. Laser diodes, also called semiconductor lasers or injection laser

  17. Monolithic series-connected gallium arsenide converter development

    SciTech Connect (OSTI)

    Spitzer, M.B.; McClelland, R.W.; Dingle, B.D.; Dingle, J.E.; Hill, D.S. (Kopin Corp., Taunton, MA (United States)); Rose, B.H. (Sandia National Labs., Albuquerque, NM (United States))

    1991-01-01T23:59:59.000Z

    We report the development of monolithic GaAs photovoltaic devices intended to convert light generated by a laser or other bright source to electricity. The converters described here can provide higher operating voltage than is possible using a single-junction converter, owing to use of a monolithic circuit that forms a planar series-connected string of single-junction sub-cells. This planar monolithic circuit is arranged to deliver the desired voltage and current during operation at the maximum power point. The paper describes two-, six-, and twelve-junction converters intended for illumination by a laser diode with a wavelength of 0.8 {mu}m. Design and characterization data are presented for optical power in the range of 100 mW to 1 W. The best conversion efficiency exceeds 50%. 9 refs., 4 figs., 2 tabs.

  18. Fabrication of a gated gallium arsenide heterostructure resonant tunneling diode 

    E-Print Network [OSTI]

    Kinard, William Brian

    1989-01-01T23:59:59.000Z

    ) William Brian Kinard, B. S, Texas A&M University Chair of Advisory Committee: Mark H. Weichold The objective of this research was to design and fabricate a device capable of electrically contrulhng current through a vertical resonant tunneling diode.... Addi- tionally, this modulation of current must not aB'ect the normal cperation of the resonant tunneling diode such as shifting resonant bias. Device arrays of various sizes were successfully 1'abricated for the first time utilizing unique...

  19. Rutherford backscattering analysis of gallium implanted 316 stainless steel

    E-Print Network [OSTI]

    Ortensi, Javier

    2000-01-01T23:59:59.000Z

    % was attained at 300 [] and deeper. The possible enhanced diffusion of Ga was observed, but not necessarily through the grain boundaries. Although there was no indication of compound formation, significant pitting was observed at high fluences. Repassivation...

  20. Gallium Nitride Integrated Gas/Temperature Sensors for

    E-Print Network [OSTI]

    precision and accuracy · Field test for reliability and lifetime · 1) Sensor Needs and Requirements://www.ott.doe.gov/pdfs/sensor_needs.pdf #12;4 Approach GaN based devices and circuits are an attractive option for high temperature electronic) and hydrogen (30-70%) 80% Complete 2- Determine confounding effects due to multiple components 80% Complete 3

  1. High Quality, Low Cost Bulk Gallium Nitride Substrates Grown...

    Energy Savers [EERE]

    silicon Widespread adoption of efficient load architectures enabled by GaN-based power electronics and lighting can lead to a 25% reduction in world energy consumption ...

  2. Formation mechanisms of spatially-directed zincblende gallium nitride nanocrystals

    SciTech Connect (OSTI)

    Wood, A. W. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Collino, R. R. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Cardozo, B. L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Naab, F. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Wang, Y. Q. [Materials Science and Technology Division, Los Alamos National Lab, Los Alamos, New Mexico 87545 (United States); Goldman, R. S. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2011-12-15T23:59:59.000Z

    We report on the spatially selective formation of GaN nanocrystals embedded in GaAs. Broad-area N{sup +} implantation followed by rapid thermal annealing leads to the formation of nanocrystals at the depth of maximum ion damage. With additional irradiation using a Ga{sup +} focused ion beam, selective lateral positioning of the nanocrystals within the GaAs matrix is observed in isolated regions of increased vacancy concentration. Following rapid thermal annealing, the formation of zincblende GaN is observed in the regions of highest vacancy concentration. The nucleation of zincblende nanocrystals over the wurtzite phase of bulk GaN is consistent with the predictions of a thermodynamic model for the nanoscale size-dependence of GaN nucleation.

  3. abdominal gallium-67 citrate: Topics by E-print Network

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

    species (bigeye, Thunnus obesus; yellowfin, T. albacares; and skipjack, Katsuwonus pelamis) Environmental Sciences and Ecology Websites Summary: : 26 October 2004 Key words:...

  4. aluminium gallium indium: Topics by E-print Network

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

    on which all indium abundance studies are based, both for the quiet-sun and the sunspot umbra spectrum, employing standard atmosphere models and accounting for hyperfine structure...

  5. aluminum gallium indium: Topics by E-print Network

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

    on which all indium abundance studies are based, both for the quiet-sun and the sunspot umbra spectrum, employing standard atmosphere models and accounting for hyperfine structure...

  6. amorphous indium gallium: Topics by E-print Network

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

    on which all indium abundance studies are based, both for the quiet-sun and the sunspot umbra spectrum, employing standard atmosphere models and accounting for hyperfine structure...

  7. Gallium Arsenide (GaAs) EDWARD D. PALIK

    E-Print Network [OSTI]

    Pulfrey, David L.

    constants of pure (semi-insulating) GaAs are derived from a number of papers including the far-infrared at. [4]; the near-IR work of Pikhtin and Yas'kov [5]; the calorim- etry work of Christensen et al. [6 reflection work of Philipp and Ehrenreich [9]; and the synchrotron transmission work of Cardona et al. [10

  8. Broadband electrooptic modulators based on gallium arsenide materials

    E-Print Network [OSTI]

    Shamir, Orit A

    2012-01-01T23:59:59.000Z

    Optical Arbitrary Waveform Generation (OAWG) combines frequency combs and frequency-by- frequency pulse shapers to synthesize optical waveforms. The OAWG technique has a wide variety of applications, ranging from high ...

  9. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide...

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

    Structural vacancies are a source of numerous interesting structural, electronic, and optical properties, and materials scientists often rely them as an important building...

  10. Self-aligned submicron gate length gallium arsenide MESFET 

    E-Print Network [OSTI]

    Huang, Hsien-Ching

    1987-01-01T23:59:59.000Z

    38 21. Proximity cap annealing . 22. Temperature profile of post implant anneal 46 47 23. 24. 25. 26. 27. 28. 29. 30. "Pits" or holes in GaAs post implant anneal without sacrificial cap Silicon monoxide source (bafile box) used.... 16(b)). The bottom resist layer is then further etched in the oxygen plasma to produce undercutting for the desire gate structure. The amount of undercut is determined by the desired length of the gate and is the width of the remaining resist...

  11. Process for growing epitaxial gallium nitride and composite wafers

    DOE Patents [OSTI]

    Weber, Eicke R.; Subramanya, Sudhir G.; Kim, Yihwan; Kruger, Joachim

    2003-05-13T23:59:59.000Z

    A novel growth procedure to grow epitaxial Group III metal nitride thin films on lattice-mismatched substrates is proposed. Demonstrated are the quality improvement of epitaxial GaN layers using a pure metallic Ga buffer layer on c-plane sapphire substrate. X-ray rocking curve results indicate that the layers had excellent structural properties. The electron Hall mobility increases to an outstandingly high value of .mu.>400 cm.sup.2 /Vs for an electron background concentration of 4.times.10.sup.17 cm.sup.-3.

  12. Growth and structure of sputtered gallium nitride films

    SciTech Connect (OSTI)

    Yadav, Brajesh S.; Major, S. S.; Srinivasa, R. S. [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India)

    2007-10-01T23:59:59.000Z

    GaN films have been deposited by radio frequency sputtering of a GaAs target with pure nitrogen. The growth, composition, and structure of the films deposited on quartz substrates have been studied by x-ray diffraction, transmission electron microscopy, and Raman spectroscopy. Films deposited below 300 deg. C are amorphous and As rich. Above 300 deg. C, polycrystalline, hexagonal GaN is formed, along with As rich amorphous phase, which reduces with increasing substrate temperature. At a substrate temperature of 700 deg. C, GaN films, practically free of amorphous phase, and As (<0.5 at. %) are formed. The preferred orientation depends strongly on the substrate temperature and is controlled by surface diffusion of adatoms during growth stage. Below 500 deg. C, the surface diffusion between planes dominates and results in the (1011) preferred orientation. Above 500 deg. C, the surface diffusion between grains takes over and results in (0002) preferred orientation.

  13. Electrochemical Solution Growth: Gallium Nitride Crystal Growth - Energy

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater Use

  14. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps to Predict4Vacancy announcements Alumni

  15. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps to Predict4Vacancy announcements

  16. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps to Predict4Vacancy announcementsVacancy-Induced

  17. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps to Predict4Vacancy

  18. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps to Predict4VacancyVacancy-Induced Nanoscale Wire

  19. Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate |

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

    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 onYouTube YouTube Note: Since the.pdfBreaking ofOil & Gas »ofMarketing | Department ofEnergy Nuclear

  20. Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening aTurbulenceUtilize Available Resources Print AsVacancy-Induced

  1. High-Quality, Low-Cost Bulk Gallium Nitride Substrates

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

    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 DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEND D e e p p a a r rRancho Cordoba,High-Quality,

  2. Spectroscopic evidence for a surface layer in CuInSe2 : Cu deficiency

    E-Print Network [OSTI]

    Han, Sung-Ho; Hasoon, Falah S.; Hermann, Allen M.; Levi, Dean H.

    2007-01-01T23:59:59.000Z

    labora- tory thin-?lm PX-CIGS solar cells has surpassed 19%.?CIGS? is used as the absorber layer for high ef?ciency photovoltaic solar cells.

  3. Near-surface electronic defects and morphology of CuIn1xGaxSe2 Y. M. Strzhemechnya)

    E-Print Network [OSTI]

    Rockett, Angus

    CIGS is a leading candidate for high-efficiency solar cells, yet the defects and electronic structure to the near-band-edge peak. Polycrystalline CdS/CIGS/Mo/glass and CIGS/Mo/glass solar-cell layers were also to measure the local band and defect properties of epitaxial CIGS films having 002 , 220 / 204 , or 112

  4. Curriculum Vitae 2011Present Ph.D. in Physics, Colorado State University, Fort Collins.

    E-Print Network [OSTI]

    Sites, James R.

    -PACE CIGS program, mainly focus on the device characterization and simulation of CIGS solar cells with Zn of CIGS solar cells with sputtered Zn(O,S) buffer layers (in progress) July 2013 Summer Intern, DOE-V Distortion of CIGS Solar Cells with Sputtered Zn(O,S) Buffer Layers Department of Physics, 1875 Campus

  5. Polycrystalline CuInSe{sub 2} and CdTe solar cells. Annual subcontract report, April 15, 1992--April 14, 1993

    SciTech Connect (OSTI)

    Dhere, N.G. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

    1994-08-01T23:59:59.000Z

    The principal objective of the research project is to develop processes for the fabrication of cadmium-telluride, CdTe, and copper-indium-gallium-diselenide, Cu(In{sub 1{minus}x}Ga{sub x})Se{sub 2}, polycrystalline-thin-film solar cells using techniques that can be scaled-up for economic manufacture on a large scale. The aims are to fabricate CdTe solar cells using Cd and Te layers sputtered from elemental targets; to promote the interdiffusion between Cd/Te layers, CdTe phase formation, and grain growth; to utilize non-toxic selenization so as to avoid the use of extremely toxic H{sub 2}Se in the fabrication of Cu(In{sub l{minus}x}Ga{sub x})Se{sub 2} thin-film solar cells; to optimize selenization parameters; to improve adhesion; to minimize residual stresses; to improve the uniformity, stoichiometry, and morphology of CdTe and Cu(In{sub 1{minus}x}Ga{sub x})Se{sub 2} thin films, and the efficiency of CdTe and Cu(In{sub 1{minus}x}Ga{sub x})Se{sub 2} solar cells.

  6. Photovoltaics: From the laboratory to the marketplace

    SciTech Connect (OSTI)

    Basso, T.S.; Surek, T.; Thornton, J.

    1991-03-01T23:59:59.000Z

    Photovoltaics (PV), the direct conversion of sunlight to electricity, is experiencing significant improvements in technology performance and lowered costs. Fostering these improvements, the SERI Photovoltaic Advanced Research and Development (PV AR D) Project supports research and provides services to the US PV industry. This paper presents the recent advances and future direction of the PV project. Research areas are Fundamental and Supporting Research, Advanced Thin-Film Materials, High-Efficiency Materials, Module Development, and Systems Development. Materials of interest include amorphous silicon, copper indium diselenide, cadmium telluride, crystalline silicon, gallium arsenide and related alloys, transparent conductors, antireflection coatings, substrates, and encapsulants. The PV project inherently provides technology transfer that helps industry shorten the time to bring R D advances to the marketplace. SERI annually performs over 10,000 measurements for the entire PV community, participates in collaborative research, and welcomes visiting scientists. Two specific areas of recently increased national focus are: (1) manufacturing processes for cost-effective PV modules, and (2) systems development for high-value utility applications. The SERI research approach is based on facilitating direct contact between industry, electric utilities, and others interested in PV technology. This approach heavily relies on SERI/industry partnerships. The arrangements vary to address generic and company-specific problems to improve the US industry's competitive position and accelerate greater electric utility deployment of PV systems. 5 refs., 5 figs., 6 tabs.

  7. NREL photovoltaic subcontract reports: Abstracts and document control information, 1 August 1992--31 July 1993

    SciTech Connect (OSTI)

    Not Available

    1993-09-01T23:59:59.000Z

    This report contains document control information and abstracts for the National Renewable Energy Laboratory (NREL) subcontracted photovoltaic (PV) program publications. It also lists source information on additional publications that describe US Department of Energy (DOE) PV research activities. It is not totally exhaustive, so it lists NREL contacts for requesting further information on the DOE and NREL PV programs. This report covers the period from August 1, 1992, through July 31, 1993. This report is published periodically, with the previous one covering the period from August 1, 1991, through July 31, 1992. The purpose of continuing this type of publication is to help keep people abreast of specific PV interests, while maintaining a balance on the costs to the PV program. The information in this report is organized under PV technology areas: Amorphous Silicon Research; Polycrystalline Thin Films (including copper indium diselenide, cadmium telluride, and thin-film silicon); Crystalline Materials and Advanced Concepts (including silicon, gallium arsenide, and other group III-V materials); PV Manufacturing Technology Development (which may include manufacturing information for various types of PV materials).

  8. Post-Deposition Treatment Boosts CIGS Solar Cell Performance (Fact Sheet), NREL Highlights in Research & Development, NREL (National Renewable Energy Laboratory)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeeding accessPeptoidLabPhysicsPits |RegulationsPortableDOENREL's use

  9. Joint Center for Artificial Photosynthesis

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

    Researchers at JCAP have demonstrated that illuminated photoelectrodes made from tungsten diselenide with noble metal catalysts deposited on the surface can produce hydrogen...

  10. Synthesis and Characterization of Earth Abundant and Nontoxic Metal Chalcogenides Produced via Aerosol Spray Pyrolysis for Photovoltaic Applications

    E-Print Network [OSTI]

    Davis, Patrick John

    2013-01-01T23:59:59.000Z

    diselenide, Progress in Photovoltaics, 7, 489-497, 1999. [VII-2, Practical Handbook of Photovoltaics: Fundamentals andthin films for photovoltaics: a review. EPJ Photovolt. 3, [

  11. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2011. One company in Utah

    E-Print Network [OSTI]

    % was used in research and development, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace, consumer goods, industrial equipment, medical equipment

  12. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2001. Two companies in

    E-Print Network [OSTI]

    , specialty alloys, and other applications. Optoelectronic devices were used in areas such as consumer goods, medical equipment, industrial components, telecommunications, and aerospace applications. Integrated

  13. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2000. Two companies in

    E-Print Network [OSTI]

    and development, specialty alloys, and other applications. Optoelectronic devices were used in areas such as consumer goods, medical equipment, industrial components, telecommunications, and aerospace applications

  14. (Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2003. One company in

    E-Print Network [OSTI]

    , specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace

  15. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2006. One company in Utah

    E-Print Network [OSTI]

    , specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace

  16. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2010. One company in Utah

    E-Print Network [OSTI]

    and development, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace, consumer goods, industrial equipment, medical equipment, and telecommunications. ICs were used

  17. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2007. One company in Utah

    E-Print Network [OSTI]

    and development, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace, consumer goods, industrial equipment, medical equipment, and telecommunications. ICs were used

  18. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2004. One company in Utah

    E-Print Network [OSTI]

    % was used in research and development, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace, consumer goods, industrial equipment, medical equipment

  19. (Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2008. One company in Utah

    E-Print Network [OSTI]

    and development, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace, consumer goods, industrial equipment, medical equipment, and telecommunications. ICs were used

  20. Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films

    E-Print Network [OSTI]

    Tao, Jonathan Huai-Tse

    2010-01-01T23:59:59.000Z

    Converted White-Light-Emitting Diodes," Jap. J. Appl.doped III-N Light-Emitting Diodes," Appl. Phys. Lett. , 84 (in Packaging High Power Light Emitting Diode Arrays," Appl.

  1. Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films

    E-Print Network [OSTI]

    Tao, Jonathan Huai-Tse

    2010-01-01T23:59:59.000Z

    High-Color-Rendering LED Lamps Using Oxyfluoride andHigh-pressure mercury lamp LED Luxeon white 5 W LED Cree LRpressure mercury lamps; some Cree LEDs have even comparable

  2. Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films

    E-Print Network [OSTI]

    Tao, Jonathan Huai-Tse

    2010-01-01T23:59:59.000Z

    from GaN:Tb 3+ Powders and Thin Films Deposited by MOVPE andHirata, "Eu 3+ Activated GaN Thin Films Grown on Sapphire byTb 3+ in GaN Powders and Thin Films," ECS Trans. , J. Laski,

  3. Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films

    E-Print Network [OSTI]

    Tao, Jonathan Huai-Tse

    2010-01-01T23:59:59.000Z

    Growth of Single Crystal GaN Substrate using Hydride VaporZnO Nanowire on a p-GaN Substrate," J. Phys. Chem. C , 114Grown on GaN Nanocrystalline Powder Substrate," J. Cryst.

  4. Epitaxial growth of Cu,,In,Ga...Se2 on GaAs,,110... and A. Rockett

    E-Print Network [OSTI]

    Rockett, Angus

    . INTRODUCTION The Cu(In, Ga)Se2 CIGS absorber layer in a recent record-efficiency CIGS solar cell1 has a 220.13 Commercially supplied ``epi-ready'' liquid- encapsulated Czo

  5. Presented at the 13th ICTMC, Oct 14 18, 2002

    E-Print Network [OSTI]

    Sites, James R.

    Abstract Solar cells have been fabricated with partial electrolyte treatments of CuInGaSe2 (CIGS) thin film efficient CIGS solar cells are fabricated in this manner, there are a few problems associated with the Cd by the completion of the solar cells with a ZnO layer. 2. Experimental Techniques CIGS thin films were grown at NREL

  6. In situ investigation of the selenization kinetics of CuGa precursors using time-resolved high-temperature X-ray diffraction

    E-Print Network [OSTI]

    Anderson, Timothy J.

    (CIGS) is a proven absorber material for high efficiency thin film solar cells with reported conversion- solar cell is the tandem cell structure that uses the high efficiency In-rich CIGS device as the bottom cell in a CIGS tandem solar cell structure [2­4]. Recently, a record-efficiency of 10.23% for a surface

  7. Determination of the minority carrier diffusion length in compositionally graded Cu,,In,Ga...Se2 solar cells using electron beam induced

    E-Print Network [OSTI]

    Wu, Junqiao

    .1063/1.3291046 Cu In,Ga Se2 CIGS solar cells have achieved efficien- cies above 19% using a compositionally graded,S 2 films.7­9 However, the best CIGS solar cells have a compo- sitionally graded profile.10 The graded in compositionally graded CIGS solar cells. Energy dependent EBIC measurements were collected in the planar

  8. Effect of Ga content on defect states in CuIn1xGaxSe2 photovoltaic devices

    E-Print Network [OSTI]

    Rockett, Angus

    gaps for single junction solar cells expected to be around 1.4 eV.2 This corresponds to a Ga fraction x gap of CuIn1 xGaxSe2 CIGS . This technique is sensitive to opti- cal absorption in the active layer CIGS. Photovoltaic devices based on thin polycrystalline CIGS absorbers have achieved record lab

  9. Toward microscale Cu,,In,Ga...Se2 solar cells for efficient conversion and optimized material usage: Theoretical evaluation

    E-Print Network [OSTI]

    Boyer, Edmond

    develop a model to predict the performances of microscale Cu In,Ga Se2 CIGS solar cells under concentrated limiting factor for concentration on CIGS solar cells. This model can be used to extract the value associated with the operation of microscale CIGS solar cells are studied. The optimum concentration ratio

  10. 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

  11. This content has been downloaded from IOPscience. Please scroll down to see the full text. Download details

    E-Print Network [OSTI]

    Napp, Nils

    absorbers. In this study, the effects of a graded bandgap profile on the cell performance of a CIGS solar The Japan Society of Applied Physics 1. Introduction Cu(In,Ga)Se2 (CIGS) solar cells have demonstrated a high conversion efficiency of over 20%.1) Also, the CIGS solar cells have many advantages

  12. Int'l PVSEC -121 Technical Digest of the International PVSEC-14, Bangkok, Thailand, 2004

    E-Print Network [OSTI]

    Romeo, Alessandro

    Properties of CIGS solar cells developed with evaporated II-VI buffer layers A. Romeo, R. Gysel, S. Buzzi, D in Voc and FF are measured. 1. Introduction High efficiency CIGS solar cells have been obtained. We present a comparison of the CIGS based solar cells made with CBD, PVD-CdS and PVD-Zn-based buffer

  13. Simulation of Polycrystalline Cu(In,Ga)Se2 Solar Cells in Two Dimensions Markus Gloeckler, Wyatt K. Metzger1

    E-Print Network [OSTI]

    Sites, James R.

    10%­12% [2]. This work uses numerical simulations to predict the changes to CIGS solar-cell an electrostatic potential, which has been reported in the literature for CIGS solar cells [3­5]. A valence that a plausible reason behind highly efficient thin-film CIGS solar cells ( > 17%) is an inherent valence

  14. Gallium surface diffusion on GaAs (001) surfaces measured by crystallization dynamics of Ga droplets

    SciTech Connect (OSTI)

    Bietti, Sergio, E-mail: sergio.bietti@mater.unimib.it; Somaschini, Claudio; Esposito, Luca; Sanguinetti, Stefano [L–NESS and Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 55, I–20125 Milano (Italy); Fedorov, Alexey [L–NESS and CNR–IFN, via Anzani 42, I-22100 Como (Italy)

    2014-09-21T23:59:59.000Z

    We present accurate measurements of Ga cation surface diffusion on GaAs surfaces. The measurement method relies on atomic force microscopy measurement of the morphology of nano–disks that evolve, under group V supply, from nanoscale group III droplets, earlier deposited on the substrate surface. The dependence of the radius of such nano-droplets on crystallization conditions gives direct access to Ga diffusion length. We found an activation energy for Ga on GaAs(001) diffusion E{sub A}=1.31±0.15 eV, a diffusivity prefactor of D{sub 0}?=?0.53(×2.1±1) cm{sup 2} s{sup ?1} that we compare with the values present in literature. The obtained results permit to better understand the fundamental physics governing the motion of group III ad–atoms on III–V crystal surfaces and the fabrication of designable nanostructures.

  15. Fabrication of an optically driven 10 GHz ring resonator on a gallium arsenide substrate

    E-Print Network [OSTI]

    McGregor, Douglas Scott

    1989-01-01T23:59:59.000Z

    /D converters, optical detectors, dc to rf converters, and millimeter-wave or microwave generators. Photoconductors can be easily integrated with microelectronic devices as well as microwave circuits. Recently, an optically excited photoconductive switch... is the barrier height and y, is the electron affinity for the semiconductor. Current flow at a metal-semiconductor barrier is due mainly to majority carriers. The four major current transport methods are thermionic emission over the barrier, quantum...

  16. Synthesis, characterization, and biotemplated assembly of indium nitride and indium gallium nitride nanoparticles

    E-Print Network [OSTI]

    Hsieh, Jennifer Chia-Jen

    2010-01-01T23:59:59.000Z

    A low-temperature, ambient pressure solution synthesis of colloidal InN nanoparticles is presented. This synthesis utilizes a previously dismissed precursor and results in individual, non-aggregated nanoparticles with ...

  17. Non-Destructive Spent Fuel Characterization with Semi-Conducting Gallium Arsinde Neutron Imaging Arrays

    SciTech Connect (OSTI)

    Douglas S. McGregor; Holly K. Gersch; Jeffrey D. Sanders; John C. Lee; Mark D. Hammig; Michael R. Hartman; Yong Hong Yang; Raymond T. Klann; Brian Van Der Elzen; John T. Lindsay; Philip A. Simpson

    2002-01-30T23:59:59.000Z

    High resistivity bulk grown GaAs has been used to produce thermal neutron imaging devices for use in neutron radiography and characterizing burnup in spent fuel. The basic scheme utilizes a portable Sb/Be source for monoenergetic (24 keV) neutron radiation source coupled to an Fe filter with a radiation hard B-coated pixellated GaAs detector array as the primary neutron detector. The coated neutron detectors have been tested for efficiency and radiation hardness in order to determine their fitness for the harsh environments imposed by spent fuel. Theoretical and experimental results are presented, showing detector radiation hardness, expected detection efficiency and the spatial resolution from such a scheme. A variety of advanced neutron detector designs have been explored, with experimental results achieving 13% thermal neutron detection efficiency while projecting the possibility of over 30% thermal neutron detection efficiency.

  18. Radiolabeled porphyrin versus gallium-67 citrate for the detection of human melanoma in athymic mice

    SciTech Connect (OSTI)

    Maric, N.; Chan, S. Ming; Hoffer, P.B.; Duray, P.

    1987-01-01T23:59:59.000Z

    We performed the biodistribution and imaging studies of /sup 111/In and /sup 67/Ga labeled tetra(4-N-methylpyridyl) porphine, (T4NMPYP), and compared it to that of /sup 67/Ga citrate in athymic mice bearing a human melanoma xenograft. The biodistribution results of both /sup 111/In and /sup 67/Ga labeled T4NMPYP (3, 6, 24, and 48 hours) were similar but differed from that of /sup 67/Ga citrate (48 hours). The optimum tumor uptake of both radiolabeled porphyrins was at 6 hours postinjection and was lower than the tumor uptake of /sup 67/Ga citrate at 48 hours postinjection. Kidney was the only organ showing higher uptake of radiolabeled porphyrin compared to that of /sup 67/Ga citrate. The imaging studies performed with /sup 111/In T4NMPYP and /sup 67/Ga citrate correspond to the biodistribution results. Osteomyelitis present in one mouse showed good localization of /sup 111/In T4NMPYP. 15 refs., 3 figs., 5 tabs.

  19. Electrical properties of atomic layer deposited aluminum oxide on gallium nitride

    SciTech Connect (OSTI)

    Esposto, Michele; Krishnamoorthy, Sriram; Nath, Digbijoy N.; Bajaj, Sanyam; Hung, Ting-Hsiang; Rajan, Siddharth

    2011-09-26T23:59:59.000Z

    We report on our investigation of the electrical properties of metal/Al{sub 2}O{sub 3}/GaN metal-insulator-semiconductor capacitors. We determined the conduction band offset and interface charge density of the alumina/GaN interface by analyzing the capacitance-voltage characteristics of atomic layer deposited Al{sub 2}O{sub 3} films on GaN substrates. The conduction band offset at the Al{sub 2}O{sub 3}/GaN interface was calculated to be 2.13 eV, in agreement with theoretical predications. A non-zero field of 0.93 MV/cm in the oxide under flat-band conditions in the GaN was inferred, which we attribute to a fixed net positive charge density of magnitude 4.60 x 10{sup 12 }cm{sup -2} at the Al{sub 2}O{sub 3}/GaN interface. We provide hypotheses to explain the origin of this charge by analyzing the energy band line-up.

  20. Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits

    E-Print Network [OSTI]

    Bickford, Justin Robert

    2008-01-01T23:59:59.000Z

    is limited by the cold-wall chamber design and the porousrepeatability. The cold-wall chamber design also limits the

  1. Commercialization of gallium nitride nanorod arrays on silicon for solid-state lighting

    E-Print Network [OSTI]

    Wee, Qixun

    2008-01-01T23:59:59.000Z

    One important component in energy usage is lighting, which is currently dominated by incandescent and fluorescent lamps. However, due to potentially higher efficiencies and thus higher energy savings, solid-state lighting ...

  2. The equilibrium state of hydrogen in gallium nitride: Theory and experiment

    SciTech Connect (OSTI)

    MYERS JR.,SAMUEL M.; WRIGHT,ALAN F.; PETERSEN,GARY A.; SEAGER,CARLETON H.; WAMPLER,WILLIAM R.; CRAWFORD,MARY H.; HAN,JUNG

    2000-04-17T23:59:59.000Z

    Formation energies and vibrational frequencies for H in wurtzite GaN were calculated from density functional theory and used to predict equilibrium state occupancies and solid solubilities for p-type, intrinsic, and n-type material. The solubility of deuterium (D) was measured at 600--800 C as a function of D{sub 2} pressure and doping and compared with theory. Agreement was obtained by reducing the H formation energies 0.2 eV from ab-initio theoretical values. The predicted stretch-mode frequency for H bound to the Mg acceptor lies 5% above an observed infrared absorption attributed to this complex. It is concluded that currently recognized H states and physical processes account for the equilibrium behavior of H examined in this work.

  3. Diffusion, Uptake and Release of Hydrogen in p-type Gallium Nitride: Theory and Experiment

    SciTech Connect (OSTI)

    MYERS JR.,SAMUEL M.; WRIGHT,ALAN F.; PETERSEN,GARY A.; WAMPLER,WILLIAM R.; SEAGER,CARLETON H.; CRAWFORD,MARY H.; HAN,JUNG

    2000-06-27T23:59:59.000Z

    The diffusion, uptake, and release of H in p-type GaN are modeled employing state energies from density-function theory and compared with measurements of deuterium uptake and release using nuclear-reaction analysis. Good semiquantitative agreement is found when account is taken of a surface permeation barrier.

  4. Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits

    E-Print Network [OSTI]

    Bickford, Justin Robert

    2008-01-01T23:59:59.000Z

    and Applications, edited by T. M. Tritt, ( Kluwer Academic /and Applications, edited by T. M. Tritt, ( Kluwer Academic /and Applications, edited by T. M. Tritt, ( Kluwer Academic /

  5. SAGE: Solar Neutrino Data from SAGE, the Russian-American Gallium Solar Neutrino Experiment

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    SAGE Collaboration

    SAGE is a solar neutrino experiment based on the reaction 71Ga + n goes to 71Ge + e-. The 71Ge atoms are chemically extracted from a 50-metric ton target of Ga metal and concentrated in a sample of germane gas mixed with xenon. The atoms are then individually counted by observing their decay back to 71Ga in a small proportional counter. The distinguishing feature of the experiment is its ability to detect the low-energy neutrinos from proton-proton fusion. These neutrinos, which are made in the primary reaction that provides the Sun's energy, are the major component of the solar neutrino flux and have not been observed in any other way. To shield the experiment from cosmic rays, it is located deep underground in a specially built facility at the Baksan Neutrino Observatory in the northern Caucasus mountains of Russia. Nearly 100 measurements of the solar neutrino flux have been made during 1990-2000, and their combined result is a neutrino capture rate that is well below the prediction of the Standard Solar Model. The significant suppression of the solar neutrino flux that SAGE and other solar neutrino experiments have observed gives a strong indication for the existence of neutrino oscillations. [copied from the SAGE homepage at http://ewi.npl.washington.edu/SAGE/SAGE.html

  6. Synthesis and optical properties of CsC1-doped gallium-sodium-sulfide glasses

    SciTech Connect (OSTI)

    Hehlen, Markus P [Los Alamos National Laboratory; Bennett, Bryan L [Los Alamos National Laboratory; Williams, Darrick J [Los Alamos National Laboratory; Muenchausen, Ross E [Los Alamos National Laboratory; Castro, Alonso [Los Alamos National Laboratory; Tornga, Stephanie C [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    Ga{sub 2}S{sub 3}-Na{sub 2}S (GNS) glasses doped with CsCl were synthesized in open crucibles under inert atmosphere. The evaporative loss of CsCl during glass melting was measured by energy dispersive X-ray spectroscopy and corrected for by biasing the CsCl concentration in the mixture of starting materials to obtain glasses with accurately controlled stoichiometry. Glass transition temperatures, refractive index dispersions, and band edge energies were measured for four GNS:CsCl glasses, and the respective values were found to significantly improve over earlier studies that did not mitigate CsCl evaporative losses. The refractive index dispersion measurements indicate that the Cs{sup +} and Cl{sup -} radii are 16% larger in GNS:CsCl glass than in bulk crystalline CsCl. The band edge energy increases from 2.97 eV in GNS glass to 3.32 eV in GNS glass doped with 20 mol% CsCl as a result of introducing Cl{sup -} ions having a large optical electronegativity. The large bandgap of 3.32 eV and the low (450 cm{sup -1}) phonon energy make GNS:20%CsCl an attractive host material for rare-earth ions with radiative transitions in the near ultra-violet, visible, and near-infrared spectral regions.

  7. The marine geochemistry of dissolved gallium: A comparison with dissolved aluminum

    SciTech Connect (OSTI)

    Orians, K.J.; Bruland, K.W. (Univ. of California, Santa Cruz (USA))

    1988-12-01T23:59:59.000Z

    Dissolved Ga concentrations in the pacific Ocean range from 2 to 30 picomolar: they are low in surface waters (2-12 pM), with a subsurface maximum at 150-300 m (6-17 pM), a mid-depth minimum from 500 to 1,000 m (4-10 pM) and increasing values with depth to a maximum in the bottom waters (12-30 pM). The highest concentrations are in the central gyre, with lower values toward the north and east where productivity and particle scavenging increase. Dissolved Ga concentrations in the surface waters of the northwest Atlantic are nearly an order of magnitude higher than in the central North pacific, with higher values in the Gulf Stream than in the continental slope boundary region. The vertical distributions and horizontal transects indicate three sources of dissolved Ga to the oceans. The surface distribution reflects an eolian source with no net fluvial input to the open ocean; the subsurface maximum (a feature not seen for North Pacific dissolved Al) is attributed to vertical exchange processes; the source for the deep waters of the North Pacific is from a sediment surface remineralization process or a pore water flux. Scavenging removal throughout the water column is evident in the vertical profiles for both dissolved Ga and Al, with intensified removal in the boundary regions where productivity and particle scavenging are at a maximum. Residence times of dissolved Ga in surface waters are nearly an order of magnitude longer than the corresponding values for Al.

  8. Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits

    E-Print Network [OSTI]

    Bickford, Justin Robert

    2008-01-01T23:59:59.000Z

    process: after sample pair wax wetting. .. 311 Figureprocess: after PMGI and wax dissolution and composite1. Picture of an example wax wetting two microscope slide

  9. Tungsten-incorporation induced red-shift in the bandgap of gallium oxide thin films

    SciTech Connect (OSTI)

    Rubio, E. J.; Ramana, C. V. [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)] [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)

    2013-05-13T23:59:59.000Z

    Tungsten (W) incorporated Ga{sub 2}O{sub 3} films were produced by co-sputter deposition. W-concentration was varied by the applied sputtering-power. The structure and optical properties of W-incorporated Ga{sub 2}O{sub 3} films were evaluated using X-ray diffraction, scanning electron microscopy, and spectrophotometric measurements. No secondary phase formation was observed in W-incorporated Ga{sub 2}O{sub 3} films. W-induced effects were significant on the structure and optical properties of Ga{sub 2}O{sub 3} films. The bandgap of Ga{sub 2}O{sub 3} films without W-incorporation was {approx}5 eV. Red-shift in the bandgap was noted with increasing W-concentration indicating the electronic structure changes in W-Ga{sub 2}O{sub 3} films. A functional relationship between W-concentration and optical property is discussed.

  10. Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits

    E-Print Network [OSTI]

    Bickford, Justin Robert

    2008-01-01T23:59:59.000Z

    4240 OUTPUT 708;"B12X" ! turns TEG-1 bubbler off 4250 OUTPUT708;"B8X" ! turns TEG-2,3 bubbler off 4260 OUTPUT 708;"OUTPUT 709;"B11X" ! turns TEG-1 out off OUTPUT 709;"B7X" !

  11. The determination of titanium, germanium and gallium by charged particle activation analysis

    E-Print Network [OSTI]

    Novak, Leo Robert

    1975-01-01T23:59:59.000Z

    . 3 hz 0. 559 3. 008 -13. 540 5. 143 2. 859 -11. 529 9. 0 x 10 5 1. 10 x 10 5 9. 31 x 10 5 1. 35 x 10 5 1. 17 x 10 5 70 69 Ge (p, pn) Ge 74 11 se(p, o) As 76 72 Se(p, an) As -11. 529 ' 0. 545 10. 245 a) dps per NA for 1 minute.... 85 x 10 74 Se(d, nn) As 71 1. 680 Ge(6, 2n) As 72 26. 0 hr . 834 7. 367 2. 86 x 10 746 (0 ) 72A 6. 718 "Ge(d. n) ' As Ge (d, 2n) As 17. 76 d . 596 6. 176 - 5. 570 2. 72 x 10 As(d, dn) As -10. 248 a) dps per VA for 1 minute irradietions, natural...

  12. The Hall mobility measurement of Liquid Phase Epitaxy grown aluminum gallium arsenide

    E-Print Network [OSTI]

    Choi, Young-Shig

    1986-01-01T23:59:59.000Z

    -type AJGaAs mobility as a function of doping concentration with temperature as a, parameter. . 51 CHAPTER I INTRODUCTION AI?Ga& ?As (x is the mole fraction of Al) has been employed to fabricate discrete Light Emitting Diodes (LED) and Laser Diodes... grown l&y 1. PE are the lasers and light, -emitting diodes, 2, 31. 10 One limitation of the LPE technique is the difficulty of growing layers that differ in lattice constant by more than lv/& from the substrate. Lattice mismatch, occuring whenever...

  13. Electrical properties of TiN on gallium nitride grown using different deposition conditions and annealing

    SciTech Connect (OSTI)

    Li, Liuan; Kishi, Akinori; Shiraishi, Takayuki; Jiang, Ying; Wang, Qingpeng; Ao, Jin-Ping, E-mail: jpao@ee.tokushima-u.ac.jp [Institute of Technology and Science, The University of Tokushima, Tokushima 770-8506 (Japan)

    2014-03-15T23:59:59.000Z

    This study evaluates the thermal stability of different refractory metal nitrides used as Schottky electrodes on GaN. The results demonstrate that TiN, MoSiN, and MoN possess good rectification and adhesion strength, with barrier heights of 0.56, 0.54, and 0.36?eV, respectively. After thermal treatment at 850?°C for 1?min, the TiN and MoN electrodes still exhibit rectifying characteristics, while the MoSiN degrades to an ohmic-like contact. For further study, several TiN films are deposited using different N{sub 2}/Ar reactive/inert sputtering gas ratios, thereby varying the nitrogen content present in the sputtering gas. Ohmic-like contact is observed with the pure Ti contact film, and Schottky characteristics are observed with the samples possessing nitrogen in the film. The average Schottky barrier height is about 0.5?eV and remains virtually constant with varying nitrogen deposition content. After examining Raman spectra and x-ray photoelectron spectroscopy results, the increase in the film resistivity after thermal treatment is attributed to oxidation and/or nitridation. Films deposited with a medium (40% and 60%) nitrogen content show the best film quality and thermal stability.

  14. Gallium-68 Bioorthogonal Tetrazine Polymers for the Multistep Labeling of Cancer Biomarkers /

    E-Print Network [OSTI]

    Nichols, Brandon Edward

    2013-01-01T23:59:59.000Z

    68 somatostatin receptor PET/CT: is it time to replace (111)mapping of the prostate using PET/CT fusion imaging and Ga-

  15. Nanoheteroepitaxy of gallium arsenide on strain-compliant silicon-germanium nanowires

    SciTech Connect (OSTI)

    Chin, Hock-Chun; Gong, Xiao; Yeo, Yee-Chia [Department of Electrical and Computer Engineering, National University of Singapore (NUS), Singapore 117576 (Singapore); Ng, Tien Khee; Loke, Wan Khai; Wicaksono, Satrio; Yoon, Soon Fatt [School of Electrical and Electronic Engineering, Nanyang Technological University (NTU), Nanyang Avenue, Singapore 639798 (Singapore); Wong, Choun Pei; Shen, Zexiang [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University (NTU), Singapore 637371 (Singapore)

    2010-07-15T23:59:59.000Z

    Heterogeneous integration of high-quality GaAs on Si-based substrates using a selective migration-enhanced epitaxy (MEE) of GaAs on strain-compliant SiGe nanowires was demonstrated for the first time. The physics of compliance in nanoscale heterostructures was captured and studied using finite-element simulation. It is shown that nanostructures can provide additional substrate compliance for strain relief and therefore contribute to the formation of defect-free GaAs on SiGe. Extensive characterization using scanning electron microscopy and cross-sectional transmission electron microscopy was performed to illustrate the successful growth of GaAs on SiGe nanowire. Raman and Auger electron spectroscopy measurements further confirmed the quality of the GaAs grown and the high growth selectivity of the MEE process.

  16. Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits

    E-Print Network [OSTI]

    Bickford, Justin Robert

    2008-01-01T23:59:59.000Z

    lasers utilizing an InGaP etch-stop layer,” Semiconductor1992). Cirtic acid GaAs from InGaP: D. Arslan, A. Dehé, and1999). Hydrochloric acid InGaP from GaAs: J. R. Lothian, J.

  17. amorphous indium-gallium-zinc oxide: Topics by E-print Network

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

    Summary: alloy of composition correspond- ing to the metallic components of the superconduct- ing oxides respectivement. Abstract. - Previous quenching experiments on 2212...

  18. Radiation-Hardened Gallium Nitride Detector and Arrays for Fusion Diagnostics

    SciTech Connect (OSTI)

    Sun, K. X., and MacNeil, L.

    2011-09-08T23:59:59.000Z

    This poster reports testing to confirm that GaN devices exhibit the extreme radiation hardness needed for use at the NIF, functioning properly after 1x10{sup 12} protons/cm{sup 2} proton irradiation in one year.

  19. X-ray photoelectron spectroscopy of gallium nitride films grown by radical-beam gettering epitaxy

    SciTech Connect (OSTI)

    Rogozin, I. V. [Berdyansk State Pedagogical University (Ukraine)], E-mail: rogozin@bdpu.org; Kotlyarevsky, M. B. [Academy of Management and Information Technology (Ukraine)

    2007-05-15T23:59:59.000Z

    Thin GaN films were grown on GaAs(111) substrates by radical-beam gettering epitaxy. The structural quality of the films was studied by high-resolution x-ray diffraction. The chemical composition of the GaAs surface and GaN film was studied by x-ray photoelectron spectroscopy. It is shown that Ga-N and As-N bonds are formed on the GaAs surface at initial growth stages at low temperatures. The state of the film-substrate interface was studied. It was found that prolonged annealing of GaN films in nitrogen radicals shifts the composition to nitrogen excess.

  20. Fabrication of optoelectronic microwave linear and ring resonators on a gallium arsenide substrate 

    E-Print Network [OSTI]

    Yeh, Chun-Liang

    1993-01-01T23:59:59.000Z

    the frequency ~, = urn' +amoco) have been observed. In the third part of the optical tests, the degenerate parametric amplification of an optical signal RF modulated at the first mode of the resonator with a microwave pumping LO at second mode... for the ring resonator. 77 46 Mixing Test Setup. 79 47 The sum signal IF, for the linear resonator with 10 prn coupling gap. The RF signal is at 4. 875 GHz and the I, O signal is at 4. 750 GHz, where the IF, signal (users = ans + uiqo) is detected at 9. 624...

  1. Gallium Arsenide-Based Readout Electronics Thomas J. Cunningham and Eric R. Fossum

    E-Print Network [OSTI]

    Fossum, Eric R.

    susceptible to radiation and hot carrier damage than are MaS-based structures. This should result in increased;among these has been the construction of optical emitters such as LEDs and lasers, since efficient

  2. Gallium arsenide-based ternary compounds and multi-band-gap solar cell research

    SciTech Connect (OSTI)

    Vernon, S. (Spire Corp., Bedford, MA (United States))

    1993-02-01T23:59:59.000Z

    Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

  3. Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits

    E-Print Network [OSTI]

    Bickford, Justin Robert

    2008-01-01T23:59:59.000Z

    affect the Ni heater photolithography step, but with properstep impulse current is driven through a monolithic heater

  4. High Quality, Low Cost Bulk Gallium Nitride Substrates Grown by the Electrochemical Solution Growth Method

    Broader source: Energy.gov (indexed) [DOE]

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaefer To:Department of EnergySeacrist, Senior Fellow - Emerging Technologies

  5. High-Quality, Low-Cost Bulk Gallium Nitride Substrates | Department of

    Broader source: Energy.gov (indexed) [DOE]

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy ChinaofSchaefer To:Department of EnergySeacrist, SeniorVolume 6 Building

  6. Sandia Energy - BES Web Highlight: Single-mode gallium nitride nanowire

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome ton6Andy

  7. Gallium Safety in the Laboratory INEEL/CON-03-00078

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR57451DOE/SC0002390dV DOE/m/10412 - 6 PROGWM:This

  8. CIBS Solar Cell Development Final Scientific/Technical Report

    SciTech Connect (OSTI)

    Exstrom, Christopher L.; Soukup, Rodney J.; Ianno, Natale J.

    2011-09-28T23:59:59.000Z

    Efforts to fabricate and study a new photovoltaic material, copper indium boron diselenide (CuInxB1-xSe2 or CIBS), were undertaken. Attempts to prepare CIBS using sputtering deposition techniques resulted in segregation of boron from the rest of elements in the material. CIBS nanocrystals were prepared from the reaction of elemental Se with CuCl, InCl3, and boric acid in solution, but the product material quickly decomposed upon heating that was required in attempts to convert the nanocrystals into a thin film. The investigation of the reasons for the lack of CIBS material stability led to new structure-property studies of closely-related photovoltaic systems as well as studies of new solar cell materials and processing methods that could enhance the development of next-generation solar technologies. A detailed compositional study of CuIn1-xAlxSe2 (CIAS, a system closely related to CIBS) revealed a non-linear correlation between crystal lattice size and the Al/(In+Al) ratios with dual-phase formation being observed. A new nanocrystal-to-thin-film processing method was developed for the preparation of CuIn1-xGaxSe2 (CIGS) thin films in which colloidal Se particles are sprayed in contact with CuIn1-xGaxS2 nanoparticles and heated in an argon atmosphere with no other Se source in the system. The process is non-vacuum and does not require toxic gases such as Se vapor or H2Se. Expertise gained from these studies was applied to new research in the preparation of thin-film pyrite FeS2, an attractive earth-abundant candidate material for next-generation photovoltaics. Three methods successfully produced pure pyrite FeS2 films: sulfurization of sputtered Fe films, chemical bath deposition, and sulfurization of Fe2O3 sol-gel precursors. The last method produced pinhole-free films that may be viable for device development. Nickel, platinum, and possibly carbon would appear to serve as good ohmic contact materials. While CdS has a reasonable conduction band energy match to serve as an n-type buffer material in a pyrite FeS2-based solar cell, the less toxic SnS2 is being explored for this purpose.

  9. Flexible, transparent thin film transistors raise hopes for flexible...

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

    the thin-film transistor, fabricated using single-atom-thick layers of graphene and tungsten diselenide, among other materials. The white scale bar shows 5 microns, which is...

  10. IEEE Spectrum: Thin-Film Trick Makes Gallium Arsenide Devices Cheap http://spectrum.ieee.org/semiconductors/materials/thinfilm-trick-makes-gallium-arsenide-devices-cheap[5/22/2010 1:39:13 PM

    E-Print Network [OSTI]

    Rogers, John A.

    to build devices--including solar cells and infrared cameras--using highly efficient but notoriously pricey's energy into electricity, while silicon cells max out at about 20 percent efficiency. The problem Electronics for Smart Grid Technologies &... Available... Reducing Physical Verification Cycle Times Available

  11. Cadmium-free junction fabrication process for CuInSe.sub.2 thin film solar cells

    DOE Patents [OSTI]

    Ramanathan, Kannan V. (Lakewood, CA); Contreras, Miguel A. (Golden, CA); Bhattacharya, Raghu N. (Littleton, CA); Keane, James (Lakewood, CA); Noufi, Rommel (Golden, CA)

    1999-01-01T23:59:59.000Z

    The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface. A second thin film layer of semiconductor material comprising zinc oxide is then applied in two layers. The first layer comprises a thin layer of high resistivity zinc oxide. The second relatively thick layer of zinc oxide is doped to exhibit low resistivity.

  12. Atomic layer deposition of Zn(O,S) thin films with tunable electrical properties by oxygen annealing

    E-Print Network [OSTI]

    CIGS-based solar cells use CdS,1,2 a toxic material, as an n-type buffer layer between the p-type CIGS(O,S) buffer layers in CIGS-based solar cells, much research has also been motivated to replace the expensive) is one of the most reliable materials used in thin-film solar cells, but currently the most efficient

  13. Presented at the 29th IEEE PVSC, May 20 -24, 2002 2P3.15 : Page 1 of 4

    E-Print Network [OSTI]

    Sites, James R.

    CuInxGa1-xSe2/CdS/ZnO (CIGS) solar cells have been shown to be reliable in the field, relatively low the high efficiency CIGS cells. However, brief treatment is also given to the devices fabricated previously OF CIGS(S)/BUFFER LAYERS FORMED BY THE Cd- PARTIAL ELECTROLYTE PROCESS P.K. Johnson 1 , A.O. Pudov 1 , J

  14. The radiation bio-effects of gallum-72 on leukemic cells via a gallium-transferrin complex

    E-Print Network [OSTI]

    Forbes, Christen Douglas

    1999-01-01T23:59:59.000Z

    Improved methods for treatment of leukemia would be advantageous for patients and the medical community. This thesis reports results of a study of the cytotoxicity of radiolabeled transferrin in cultured leukemic cells. K-562 cells, from...

  15. DESIGN AND ANALYSIS OF AN INTEGRATED PULSE MODULATED S-BAND POWER AMPLIFIER IN GALLIUM NITRIDE PROCESS

    SciTech Connect (OSTI)

    STEVE SEDLOCK

    2012-04-04T23:59:59.000Z

    The design of power amplifiers in any semi-conductor process is not a trivia exercise and it is often encountered that the simulated solution is qualitatively different than the results obtained. Phenomena such as oscillation occurring either in-band or out of band and sometimes at subharmonic intervals, continuous spectrum noticed in some frequency bands, often referred to as chaos, and jumps and hysteresis effects can all be encountered and render a design useless. All of these problems might have been identified through a more rigorous approach to stability analysis. Designing for stability is probably the one area of amplifier design that receives the least amount of attention but incurs the most catastrophic of effects if it is not performed properly. Other parameters such as gain, power output, frequency response and even matching may suitable mitigation paths. But the lack of stability in an amplifier has no mitigating path. In addition to of loss of the design completely there are the increased production cycle costs, costs involved with investigating and resolving the problem and the costs involved with schedule slips or delays resulting from it. The Linville or Rollett stability criteria that many microwave engineers follow and rely exclusively on is not sufficient by itself to ensure a stable and robust design. It will be shown that the universal belief that unconditional stability is obtained through an analysis of the scattering matrix S to determine if 1 and |{Delta}{sub S}| < 1 is only part of the procedure and other tools must be used to validate the criteria. The research shown contributes to the state of the art by developing a more thorough stability design technique for designing amplifiers of any class, whether that be current mode or switch mode, than is currently undertaken with the goal of obtaining first pass design success.

  16. Reflectance-difference spectroscopy of mixed arsenic-rich phases of gallium arsenide ,,001... M. J. Begarney,1

    E-Print Network [OSTI]

    Li, Lian

    rough quali- tative agreement with the experimental data. Based on more recent, first, University of California, Los Angeles, California 90095 2 Department of Physics and Laboratory for Surface closely match the RDS data, discrepancies in the energies and mag- nitudes of spectral features remain

  17. The design, construction, and testing of a nuclear fuel rod thermal simulation system to study gallium/Zircaloy interactions 

    E-Print Network [OSTI]

    Allison, Christopher Curtis

    1999-01-01T23:59:59.000Z

    ) fuel rods. The system uses electrically heated simulated fuel rods inside of a large, natural convection heat exchanger that uses lead-bismuth eutectic (LBE) (45 fluid. The simulated rods consist of small diameter...

  18. Thin films of gallium arsenide on low-cost substrates. Final technical report, July 5, 1976-December 5, 1978

    SciTech Connect (OSTI)

    Ruth, R.P.; Dapkus, P.D.; Dupuis, R.D.; Johnson, R.E.; Moudy, L.A.; Yang, J.J.; Yingling, R.D.

    1980-03-01T23:59:59.000Z

    The MO-CVD technique was applied to the growth of thin films of GaAs and GaAl As on inexpensive polycrystalline or amorphous substrate materials (primarily glasses and metals) for use in fabrication of large-area low-cost photovoltaic device structures. Trimethylgallium, arsine, and trimethylaluminum are mixed in appropriate concentrations at room temperature in the gaseous state and pyrolyzed at the substrate, which is heated in a vertical reactor chamber to temperatures of 700 to 750/sup 0/C, to produce the desired film composition and properties. Studies of the properties of grain boundaries in polycrystalline GaAs films by the use of transport measurements as a function of temperature indicated that the grain boundary regions are depleted of majority carriers by a large density of neutral traps at the grain boundary interface, causing a barrier to majority carrier flow in the material. Schottky-barrier solar cells of approx. 3 percent efficiency (simulated AM0 illumination, no AR coating) were demonstrated on thin-film polycrystalline GaAs n/n/sup +/ structures on Mo sheet, Mo film/glass, and graphite substrates. Substantial enhancement of average grain size in polycrystalline MO-CVD GaAs films on Mo sheet was obtained by the addition of HCl to the growth atmosphere during deposition. Extensive investigation of polycrystalline thin-film p-n junctions indicated that the forward voltage of such devices is apparently limited to 0.5 to 0.6V. A laboratory-type deposition apparatus for the formation of TiO/sub 2/ antireflection (AR) coatings by pyrolysis of titanium isopropoxide was assembled and tested. Detailed analyses were made of the materials and labor costs involved in the laboratory-scale fabrication of MO-CVD thin-film GaAs solar cells. Details are presented. (WHK)

  19. The overexpression of NADPH-producing enzymes counters the oxidative stress evoked by gallium, an iron mimetic

    E-Print Network [OSTI]

    Appanna, Vasu

    ), an iron (Fe) mimetic promoted an oxidative environment and elicited an antioxidative response shown to result in unregu- lated ROS production (Huang 2003). For instance, the amyloid b-peptide

  20. Electrical and Optical Properties of Transparent Conducting Homologous Compounds in the IndiumGalliumZinc Oxide System

    E-Print Network [OSTI]

    Poeppelmeier, Kenneth R.

    , smart windows, and solar cells. Tin-doped indium oxide (ITO) is the commercial TCO of choice. ITO thin TRANSPARENT conducting oxides (TCOs) are used in a wide variety of applications, such as flat-panel displays, and lower cost are desired for use in demanding ap- plications such as next-generation flat-panel displays

  1. Velocity distribution function of sputtered gallium atoms during inductively coupled argon plasma treatment of a GaAs surface

    SciTech Connect (OSTI)

    Despiau-Pujo, Emilie; Chabert, Pascal; Ramos, Raphaeel; Cunge, Gilles; Sadeghi, Nader [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau (France); Laboratoire des Technologies de la Microelectronique, CNRS, 38054 Grenoble (France)

    2009-03-15T23:59:59.000Z

    A GaN laser diode at 403.3 nm is used to measure the velocity distribution function (vdf) of Ga atoms sputtered from a radio-frequency biased GaAs substrate in a low pressure inductively coupled plasma (ICP) argon discharge. To investigate both perpendicular (V{sub z} normal to wafer) and longitudinal (V{sub x} parallel to wafer) velocity components, laser induced fluorescence (LIF) measurements are performed in the z direction and atomic absorption spectroscopy (AAS) in the x direction. The longitudinal vdf of Ga sputtered atoms is very close to a Lorentzian function with V{sub x} comprised between 0 and 7500 m s{sup -1}, while the perpendicular velocities V{sub z} can reach 10 000 m s{sup -1}. Experimental results are compared to molecular dynamics (MD) simulations of Ar{sup +} ion sputtering of GaAs under 200 eV bombardment. MD predictions and experiments are in fairly good agreement, which confirms the existence of products sputtered from the surface with kinetic energies larger than 10 eV. In etching processes dominated by physical bombardment, these energetic atoms could alter passivation layers on sidewalls and be responsible for defects observed in nanodevices. The best fit of the Doppler-broadened LIF and AAS profiles with the vdfs predicted by sputtering theory allows one to estimate the surface binding energy of Ga atoms in GaAs, E{sub b}, to be around 3 eV.

  2. The influence of random indium alloy fluctuations in indium gallium nitride quantum wells on the device behavior

    SciTech Connect (OSTI)

    Yang, Tsung-Jui; Wu, Yuh-Renn, E-mail: yrwu@ntu.edu.tw [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Shivaraman, Ravi; Speck, James S. [Department of Materials, University of California, Santa Barbara, California 93106 (United States)

    2014-09-21T23:59:59.000Z

    In this paper, we describe the influence of the intrinsic indium fluctuation in the InGaN quantum wells on the carrier transport, efficiency droop, and emission spectrum in GaN-based light emitting diodes (LEDs). Both real and randomly generated indium fluctuations were used in 3D simulations and compared to quantum wells with a uniform indium distribution. We found that without further hypothesis the simulations of electrical and optical properties in LEDs such as carrier transport, radiative and Auger recombination, and efficiency droop are greatly improved by considering natural nanoscale indium fluctuations.

  3. THSE DE DOCTORAT Spcialit Physique

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -thin GaAs and CIGS solar cells soutenue le 18 Décembre 2013 Composition du jury : M. PELOUARD Jean-Luc LPN

  4. Novel Materials Development for Polycrystalline Thin-Film Solar Cells: Final Subcontract Report, 26 July 2004--15 June 2008

    SciTech Connect (OSTI)

    Keszler, D. A.; Wager, J. F.

    2008-11-01T23:59:59.000Z

    Focus on player interfacial assessment using Schottky barrier and heterojunction theory, and analysis of p-windows for CIGS and CdTe cells.

  5. Synthesis and Characterization of Earth Abundant and Nontoxic Metal Chalcogenides Produced via Aerosol Spray Pyrolysis for Photovoltaic Applications

    E-Print Network [OSTI]

    Davis, Patrick John

    2013-01-01T23:59:59.000Z

    and Characterization of Earth Abundant and Nontoxic Metaland Characterization of Earth Abundant and Nontoxic Metalalternatives to CIGS with all earth abundant and non-toxic

  6. amiga project quantification: Topics by E-print Network

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

    of the isolation of 950 CIG galaxies CERN Preprints Summary: The role of the environment on galaxy evolution is still not fully understood. In order to quantify and...

  7. Synthesis and Characterization of Earth Abundant and Nontoxic Metal Chalcogenides Produced via Aerosol Spray Pyrolysis for Photovoltaic Applications

    E-Print Network [OSTI]

    Davis, Patrick John

    2013-01-01T23:59:59.000Z

    Renewable Energy Laboratory. CIGS PV Technology: Challenges, Opportunities, and Potential.renewable energy has a lot of room for growth, and solar energy has an even greater potential.

  8. additional cu layer: Topics by E-print Network

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

    PX-CIGS used in photovoltaicphotovoltaic solar cells. The ef?ciency of labora- tory thin-?photovoltaic device. Spectroscopic ellipsometry measurements of polycrystalline...

  9. PHYSICAL REVIEW B 90, 115209 (2014) Computational search for direct band gap silicon crystals

    E-Print Network [OSTI]

    Lee, Jooyoung

    2014-01-01T23:59:59.000Z

    of microns thick, while solar cells made from direct band gap materials (such as CdTe, CIGS, or CZTS) can

  10. Microsoft Word - FY 2003 Annual Report Rev10 02_10_04.doc

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

    formulation, which has been under development at Sandia since 1997. Efficient Photovoltaic Solar Cells Becoming Widely Deployed CIGS (Cu(In,Ga)Se 2 ) is a...

  11. On the Mass Eigenstate Composition of the 8B Neutrinos from the Sun

    E-Print Network [OSTI]

    A. Kopylov; V. Petukhov

    2007-04-19T23:59:59.000Z

    The present data of gallium experiments provide indirectly the only experimental limit on the fraction of $\

  12. Occupational Medicine Implications of Engineered Nanoscale Particulate Matter

    E-Print Network [OSTI]

    Kelly, Richard J.

    2008-01-01T23:59:59.000Z

    Titanium Ytterbium Zirconium Animony Boron Carbon Cobalt Erbium Gallium Hafnium Iridium Lead Magnesium Neodymium Nitrogen

  13. Method for the chemical separation of GE-68 from its daughter Ga-68

    DOE Patents [OSTI]

    Fitzsimmons, Jonathan M.; Atcher, Robert W.

    2010-06-01T23:59:59.000Z

    The present invention is directed to a generator apparatus for separating a daughter gallium-68 radioisotope substantially free of impurities from a parent gernanium-68 radioisotope, including a first resin-containing column containing parent gernanium-68 radioisotope and daughter gallium-68 radioisotope, a source of first eluent connected to said first resin-containing column for separating daughter gallium-68 radioisotope from the first resin-containing column, said first eluent including citrate whereby the separated gallium is in the form of gallium citrate, a mixing space connected to said first resin-containing column for admixing a source of hydrochloric acid with said separated gallium citrate whereby gallium citrate is converted to gallium tetrachloride, a second resin-containing column for retention of gallium-68 tetrachloride, and, a source of second eluent connected to said second resin-containing column for eluting the daughter gallium-68 radioisotope from said second resin-containing column.

  14. Lessons from IT Ecosystems Michael Kster

    E-Print Network [OSTI]

    Zachmann, Gabriel

    -Transport-Systems Smart-Energy-Systems etc. Smart Airport as a smaller instance of a Smart City Michael Köster · CIG, TU and interact massively. IT Ecosystem: analogue to biological ecosystems based on the balance between and continuously evolving IT Ecosystems requires deep understanding of this balance. Michael Köster · CIG, TU

  15. 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

  16. RealReal heterojunctionsheterojunctions Schottky barrier current

    E-Print Network [OSTI]

    Pulfrey, David L.

    -EFFICIENCY CDTE AND CIGS THIN-FILM SOLAR CELLS: HIGHLIGHTS AND CHALLENGES. National Renewable Energy Laboratory1 RealReal heterojunctionsheterojunctions LECTURE 9 · Schottky barrier current · CdS/CIGS · Energy is the forward-bias current? #12;33 HeterostructureHeterostructure, thin film, cells: a lower, thin film, cells

  17. Subscriber access provided by UNIV TORONTO Chemistry of Materials is published by the American Chemical Society. 1155

    E-Print Network [OSTI]

    of solar cells, is sought. An attractive alternative is the synthesis of nontoxic CuInS2, CuInSe2, and Cu(InGa)Se2 (CIGS). Polycrystalline CIGS films offer an alternative solar energy conversion material-generation solar cells having >30% AM1.5 power conversion efficiencies can be achieved by stacking semiconductors

  18. Z .Thin Solid Films 372 2000 212 217 Z .Na in selenized Cu In,Ga Se on Na-containing and Na-free2

    E-Print Network [OSTI]

    Rockett, Angus

    of the substrate glass on standard Z . Z .production Cu In Ga Se CIGS -based solar cells fabricated by selenization; Selenides2 1. Introduction Z .Production of large quantities of Cu In Ga Se1yx x 2 Z . Z .CIGS -based solar solar cell performance. Impurities, both U Corresponding author. Tel.: q1-217-333-0417; fax: q1

  19. Crystal and electronic band structure of Cu2ZnSnX4 ,,X=S and Se... photovoltaic absorbers: First-principles insights

    E-Print Network [OSTI]

    Gong, Xingao

    components, and the band gap is usually not optimal for high efficiency CIGS solar cells. Currently, designing and synthesizing novel, high-efficiency, and low cost solar cell absorbers to replace CIGS has.1063/1.3074499 An ideal thin-film solar cell absorber material should have a direct band gap around 1.3­1.5 e

  20. Published on Web Date: January 18, 2011 r 2011 American Chemical Society 212 DOI: 10.1021/jz101565j |J. Phys. Chem. Lett. 2011, 2, 212217

    E-Print Network [OSTI]

    Goddard III, William A.

    compound of the promising CIGS Cu(InxGa1-x)Se2 solar devices, that LDA and GGA obtain gaps of 0.0-0.01 e in these studies was to study the properties of the Cu(InxGa1-x)Se2 (CIGS) class ofsolar cells, pioneered by NREL

  1. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    CIGS, so the addition of the dc layer would not alter the material choice for a solar cell.solar cell, the use of GaAs has recently become feasible due to scalable manufacturing techniques, and compound materials such as CIGS (

  2. Characterization of Damp-Heat Degradation of CuInGaSe2 Solar Cell Components and Devices by (Electrochemical) Impedance Spectroscopy: Preprint

    SciTech Connect (OSTI)

    Pern, F. J. J.; Noufi, R.

    2011-09-01T23:59:59.000Z

    This work evaluated the capability of (electrochemical) impedance spectroscopy (IS, or ECIS as used here) to monitor damp heat (DH) stability of contact materials, CuInGaSe2 (CIGS) solar cell components, and devices. Cell characteristics and its variation of the CIGS devices were also examined by the ECIS.

  3. Effects of gallium doping on properties of a-plane ZnO films on r-plane sapphire substrates by plasma-assisted molecular beam epitaxy

    SciTech Connect (OSTI)

    Han, Seok Kyu; Lee, Hyo Sung; Lim, Dong Seok; Hong, Soon-Ku; Yoon, Nara; Oh, Dong-Cheol; Ahn, Byung Jun; Song, Jung-Hoon; Yao, Takafumi [Department of Advanced Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Graduate School of Green Energy Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Advanced Materials Engineering, Chungnam National University, Daejeon 305-764, Republic of Korea and Graduate School of Green Energy Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Center for Optoelectronic Materials and Devices, Department of Defense Science and Technology, Hoseo University, Cheonan 330-713 (Korea, Republic of); Department of Physics, Kongju National University, Gongju 314-701 (Korea, Republic of); Center for Interdisciplinary Research, Tohoku University, Sendai 980-8587 (Japan)

    2011-05-15T23:59:59.000Z

    The authors report on the structural, optical, and electrical properties of Ga-doped a-plane (1120) ZnO films grown by plasma-assisted molecular beam epitaxy. Ga doping level was controlled by changing the Ga cell temperatures from 350 to 470 deg. C with an interval of 30 deg. C. With up to Ga cell temperatures of 440 deg. C, single crystalline Ga-doped a-plane ZnO films were grown; however, the sample with a Ga cell temperature of 470 deg. C showed polycrystalline features. The typical striated surface morphology normally observed from undoped ZnO films disappeared with Ga doping. ZnO films doped with Ga cell temperatures up to 440 deg. C did not show a significant change in full width at half maximum (FWHM) values of (1120) x-ray rocking curves by doping. The smallest FWHM values were 0.433 deg. ({phi}=90 deg.) and 0.522 deg. ({phi}=0 deg. ) for the sample with a Ga cell temperature of 350 deg. C. The polycrystalline ZnO film with excessive Ga doping at the Ga cell temperature of 470 deg. C showed significantly increased FWHM values. Hall measurements at room temperature (RT) revealed that electron concentration began to be saturated at the Ga cell temperature of 440 deg. C and electron mobility was drastically reduced at the Ga cell temperature of 470 deg. C. The carrier concentration of Ga-doped ZnO films were controlled from 7.2x10{sup 18} to 3.6x10{sup 20} cm{sup -3}. Anisotropic electrical properties (carrier concentration and Hall mobility) were observed in measurements by the van der Pauw method depending on the direction (c- or m-direction) for the undoped sample but not observed for the doped samples. RT photoluminescence (PL) spectra from the Ga-doped single crystalline ZnO films showed dominant near band edge (NBE) emissions with negligibly deep level emission. The NBE intensity in PL spectra increases with Ga doping.

  4. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    photovoltaic devices with a world record efficiency ofhigh efficiencies as compared to traditional photovoltaic

  5. Gallium Lighting, LLC, Accepts Inaugural Position on the Industry Advisory Board of UC-Light Center to Help Bring Wireless Data

    E-Print Network [OSTI]

    -Light Center to Help Bring Wireless Data Communications Capabilities to LED Lights Fayetteville, GA ­ February for their Energy Star rated products and produce some of the most energy efficient, environmentally friendly on the Industry Advisory Board for the Center for Ubiquitous Communication by Light (UC-Light Center) based

  6. Inversion by metalorganic chemical vapor deposition from N- to Ga-polar gallium nitride and its application to multiple quantum well light-emitting diodes

    SciTech Connect (OSTI)

    Hosalli, A. M.; Van Den Broeck, D. M.; Bedair, S. M. [Department of Electrical and Computer Engineering, NCSU, Raleigh, North Carolina 27695 (United States)] [Department of Electrical and Computer Engineering, NCSU, Raleigh, North Carolina 27695 (United States); Bharrat, D.; El-Masry, N. A. [Department of Material Science and Engineering, NCSU, Raleigh, North Carolina 27695 (United States)] [Department of Material Science and Engineering, NCSU, Raleigh, North Carolina 27695 (United States)

    2013-12-02T23:59:59.000Z

    We demonstrate a metalorganic chemical vapor deposition growth approach for inverting N-polar to Ga-polar GaN by using a thin inversion layer grown with high Mg flux. The introduction of this inversion layer allowed us to grow p-GaN films on N-polar GaN thin film. We have studied the dependence of hole concentration, surface morphology, and degree of polarity inversion for the inverted Ga-polar surface on the thickness of the inversion layer. We then use this approach to grow a light emitting diode structure which has the MQW active region grown on the advantageous N-polar surface and the p-layer grown on the inverted Ga-polar surface.

  7. J. Phys.: Condens. Matter 9 (1997) 95179525. Printed in the UK PII: S0953-8984(97)82806-8 An interatomic potential study of the properties of gallium

    E-Print Network [OSTI]

    Pandey, Ravi

    1997-01-01T23:59:59.000Z

    energies of intrinsic point defects reveal that vacancies are the dominant native defects in GaN. Lastly Gale Department of Physics, Michigan Technological University, Houghton, MI 49931, USA Department of Chemistry, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2AY, UK

  8. Preparation of silicon substrates for gallium-arsenide solar cells by electron-beam-pulse processing. Annual technical report, March 15, 1980-March 15, 1981

    SciTech Connect (OSTI)

    Tobin, S.P.

    1981-05-01T23:59:59.000Z

    In the past year a process has been developed for creating high-quality epitaxial layers of germanium on silicon substrates using rapid heating and cooling with a pulsed electron beam. This single-crystal germanium coating is the key to the production of high efficiency GaAs solar cells on low-cost silicon substrates in an economical manner. Thin (less than or equal to 1 ..mu..m) layers of Ge have been deposited on Si wafers by chemical vapor deposition (CVD) in single-crystal form or by vacuum evaporation in amorphous or polycrystalline form. The CVD films have given the best results, with good crystallinity and electrical properties as deposited. A persistent problem with surface roughness in the as-deposited films has been overcome by pulsed electron beam melting of the near-surface region in time periods on the order of a microsecond. The brief molten period smooths the surface features without compromising the crystallinity, electrical properties, or interfacial abruptness of the Ge film. These layers are of a quality suitable for further evaluation by GaAs growth and cell processing in the next phase of the program. Pulsed electron beam processing also serves a vital function for the evaporated Ge films, which are melted by the beam and recrystallized on the Si substrates, epitaxial single crystal Ge layers result from amorphous or polycrystalline starting films. To date results have not been as satisfactory as for CVD films; contamination from several sources has been identified as a problem. Many of these sources have been eliminated, so that a decision on the intrinsic limitations of the evaporated film approach should be made in the near future.

  9. Gallium as a Possible Target Material for a Muon Collider or Neutrino Factory X. Ding, D. Cline, UCLA, Los Angeles, CA 90095, USA

    E-Print Network [OSTI]

    McDonald, Kirk

    .J. Weggel, Particle Beam Lasers, Inc., Northridge, CA 91324, USA V.B. Graves, ORNL, Oak Ridge, TN 37830, USA the peak for nickel), Liquid state at relatively low temperature (melting point = 29.8 C) , Potential plane at z = 50 m. For this analysis we select all pions and muons with 40

  10. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    film photovoltaics [1]. This roughly doubling of efficiencyMJ photovoltaics. MJ solar cells achieve higher efficiencies

  11. Narrow energy band gap gallium arsenide nitride semi-conductors and an ion-cut-synthesis method for producing the same

    DOE Patents [OSTI]

    Weng, Xiaojun; Goldman, Rachel S.

    2006-06-06T23:59:59.000Z

    A method for forming a semi-conductor material is provided that comprises forming a donor substrate constructed of GaAs, providing a receiver substrate, implanting nitrogen into the donor substrate to form an implanted layer comprising GaAs and nitrogen. The implanted layer is bonded to the receiver substrate and annealed to form GaAsN and nitrogen micro-blisters in the implanted layer. The micro-blisters allow the implanted layer to be cleaved from the donor substrate.

  12. Rare-earth transition-metal gallium chalcogenides RE{sub 3}MGaCh{sub 7} (M=Fe, Co, Ni; Ch=S, Se)

    SciTech Connect (OSTI)

    Rudyk, Brent W.; Stoyko, Stanislav S.; Oliynyk, Anton O.; Mar, Arthur, E-mail: arthur.mar@ualberta.ca

    2014-02-15T23:59:59.000Z

    Six series of quaternary rare-earth transition-metal chalcogenides RE{sub 3}MGaCh{sub 7} (M=Fe, Co, Ni; Ch=S, Se), comprising 33 compounds in total, have been prepared by reactions of the elements at 1050 °C (for the sulphides) or 900 °C (for the selenides). They adopt noncentrosymmetric hexagonal structures (ordered Ce{sub 3}Al{sub 1.67}S{sub 7}-type, space group P6{sub 3}, Z=2) with cell parameters in the ranges of a=9.5–10.2 Å and c=6.0–6.1 Å for the sulphides and a=10.0–10.5 Å and c=6.3–6.4 Å for the selenides as refined from powder X-ray diffraction data. Single-crystal structures were determined for five members of the sulphide series RE{sub 3}FeGaS{sub 7} (RE=La, Pr, Tb) and RE{sub 3}CoGaS{sub 7} (RE=La, Tb). The highly anisotropic crystal structures consist of one-dimensional chains of M-centred face-sharing octahedra and stacks of Ga-centred tetrahedra all pointing in the same direction. Magnetic measurements on the sulphides reveal paramagnetic behaviour in some cases and long-range antiferromagnetic behaviour with low Néel temperatures (15 K or lower) in others. Ga L-edge XANES spectra support the presence of highly cationic Ga tetrahedral centres with a tendency towards more covalent Ga–Ch character on proceeding from the sulphides to the selenides. Band structure calculations on La{sub 3}FeGaS{sub 7} indicate that the electronic structure is dominated by Fe 3d-based states near the Fermi level. - Graphical abstract: The series of chalcogenides RE{sub 3}MGaS{sub 7}, which form for a wide range of rare-earth and transition metals (M=Fe, Co, Ni), adopt highly anisotropic structures containing chains of M-centred octahedra and stacks of Ga-centred tetrahedra. Display Omitted - Highlights: • Six series (comprising 33 compounds) of chalcogenides RE{sub 3}MGaCh{sub 7} were prepared. • They adopt noncentrosymmetric hexagonal structures with high anisotropy. • Most compounds are paramagnetic; some show antiferromagnetic ordering. • Ga L-edge XANES confirms presence of cationic Ga species.

  13. A thermalization energy analysis of the threshold voltage shift in amorphous indium gallium zinc oxide thin film transistors under simultaneous negative gate bias and illumination

    E-Print Network [OSTI]

    Flewitt, Andrew J.; Powell, M.J.

    2014-01-01T23:59:59.000Z

    of the display industry as it moves from liquid crystal to organic light emitting diode technology and with requirements for larger areas and higher resolutions. A number of alternative material systems to a-Si:H have emerged, including organic semiconductors...

  14. PHYSICAL REVIEW A 82, 043806 (2010) Photon self-induced spin-to-orbital conversion in a terbium-gallium-garnet crystal

    E-Print Network [OSTI]

    Marrucci, Lorenzo

    `a di Napoli "Federico II", Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy 2 INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy 3 EGO, European Gravitational Observatory, Via E. Amaldi, 56021 S. Stefano a Macerata, Cascina (PI), Italy 4 CNISM

  15. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    III! V Multijunction Solar Cells,” (2003). J. F. Geisz, etEfficiency Multi-Junction Solar Cells A thesis submitted inEfficiency Multi-Junction Solar Cells By David Michael Fong

  16. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    matched materials of Ge/GaInAs/InGaP commonly used in triplesee that Ge, GaInAs, and InGaP all have a similar latticeinitial substrate to grow an InGaP top layer followed by a

  17. Ammothermal Growth of Gan Substrates For Leds: High-Pressure Ammonothermal Process for Bulk Gallium Nitride Crystal Growth for Energy Efficient Commercially Competitive Lighting

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    Broad Funding Opportunity Announcement Project: The new GaN crystal growth method is adapted from that used to grow quartz crystals, which are very inexpensive and represent the second-largest market for single crystals for electronic applications (after silicon). More extreme conditions are required to grow GaN crystals and therefore a new type of chemical growth chamber was invented that is suitable for large-scale manufacturing. A new process was developed that grows GaN crystals at a rate that is more than double that of current processes. The new technology will enable GaN substrates with best-in-world quality at lowest-in-world prices, which in turn will enable new generations of white LEDs, lasers for full-color displays, and high-performance power electronics.

  18. Growth of c-axis oriented gallium nitride thin films on an amorphous substrate by the liquid-target pulsed laser deposition technique

    E-Print Network [OSTI]

    Kwok, Hoi S.

    nitride GaN thin films with a wurtzite structure were grown on fused silica FS substrates by pulsed laser of the current directions in GaN research is to find other alter- native substrates that not only have good as a substrate for GaN film are its excellent optical transparency, low refractive index, and good mechanical

  19. Gallium arsenide-based ternary compounds and multi-band-gap solar cell research. Annual subcontract report, 15 April 1988--14 June 1990

    SciTech Connect (OSTI)

    Vernon, S. [Spire Corp., Bedford, MA (United States)

    1993-02-01T23:59:59.000Z

    Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

  20. Gallium arsenide-based ternary compounds and multi-band-gap solar cell research. Final subcontract report, 1 April 1988--31 March 1990

    SciTech Connect (OSTI)

    Vernon, S. [Spire Corp., Bedford, MA (United States)

    1993-07-01T23:59:59.000Z

    This report describes work to achieve a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed throughout this work is metal-organic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or it may contain a p-n junction of its own and form the bottom cell of a two-junction tandem solar cell structure. The III-V material for the single-junction case is GaAs, and for the two-junction case it is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include (1) a 17.6%-efficient GaAs-on-Si solar cell; (2) an 18.5%-efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8%-efficient GaAs-on-GaAs solar cell; (4) a 28.7%-efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) the measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

  1. IIl-nitride nanowires and heterostructures : growth and optical properties on nanoscale

    E-Print Network [OSTI]

    Zhou, Xiang, Ph. D. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    Gallium nitride (GaN) and indium gallium nitride (InGaN) nanowires promise potential for further improving the electricity-to-light energy conversion efficiencies in light emitting diodes due to strain relaxation, reduced ...

  2. NREL preprints for the 23rd IEEE Photovoltaic Specialists Conference

    SciTech Connect (OSTI)

    Fitzgerald, M. [ed.

    1993-05-01T23:59:59.000Z

    Topics covered include various aspects of solar cell fabrication and performance. Aluminium-gallium arsenides, cadmium telluride, amorphous silicon, and copper-indium-gallium selenides are all characterized in their applicability in solar cells.

  3. Processing Materials Devices and Diagnostics for Thin Film Photovoltaics: Fundamental and Manufacturability Issues; Final Report, 5 September 2001 - 31 May 2008

    SciTech Connect (OSTI)

    Birkmire, R. W.; Shafarman, W. N.; Eser, E.; Hegedus, S. S.; McCandless, B. E.; Dobson, K. D.; Bowden, S.

    2009-04-01T23:59:59.000Z

    The critical issues addressed in this study on CIGS, CdTe, and a-Si modules will provide the science and engineering basis for developing viable commercial processes and improved module performance.

  4. Advanced Materials and Nano Technology for Solar Cells

    E-Print Network [OSTI]

    Han, Tao

    2014-01-01T23:59:59.000Z

    Solar Energy Materials and Solar Cells 93.6 (2009): 670-673.1-3: The structure diagram of c-Si solar cell and HIT solarof flexible CIGS solar cells and modules." Solar Energy

  5. Reliability Challenges for Solar Energy (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2009-04-27T23:59:59.000Z

    PV industry can benefit from reliability testing experience of microelectronics industry . Si modules perform well in field; CdTe/CIGS must be sealed to moisture; CPV in product development stage.

  6. Solar Energy Materials & Solar Cells 91 (2007) 924930 Plasma-enhanced chemical vapor deposition of zinc oxide at

    E-Print Network [OSTI]

    Hicks, Robert F.

    2007-01-01T23:59:59.000Z

    Solar Energy Materials & Solar Cells 91 (2007) 924­930 Plasma-enhanced chemical vapor deposition (CIGS) or plastic substrates [1,2,8]. In this paper, we report on the deposition of aluminum- doped zinc

  7. Cu(In,Ga)Se2 alloys are the leading choice for absorber layers in high-efficiency thin film solar cells due to their direct gap, high absorption

    E-Print Network [OSTI]

    Rockett, Angus

    film solar cells due to their direct gap, high absorption coefficient and excellent thermal stability Cu(In,Ga)Se2 are used to interpret PL results. ·No evidence of band-to-band transitions (rare in CIGS

  8. PhotovoltagePhotovoltage andand photopowerphotopower dark current

    E-Print Network [OSTI]

    Pulfrey, David L.

    alternative (?) Sec. 7.6.1 Noufi, Rommel; Ken Zweibel. HIGH-EFFICIENCY CDTE AND CIGS THIN-FILM SOLAR CELLS;99 HeterostructureHeterostructure, thin film, cells: a lower, thin film, cells: a lower cost alternative (?)cost

  9. JAHRESBERICHT Laboratorium fur Festkorperphysik

    E-Print Network [OSTI]

    Leonardo, Degiorgi

    Z¨urich #12;Cover page: Flexible CIGS solar cells on a 25cm2 polyimide substrate. The demonstrated conversion efficiency of 14.1 % sets a new world record for flexible solar cells on polymers. The solar cells

  10. Thse prsente pour obtenir le grade de DOCTEUR DE L'COLE POLYTECHNIQUE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and technology . . . . . . . . . . . . . . . . . . 6 2.1.2 CIGS solar cell for solar cells 5 2.1 Photovoltaic solar cells . . . . . . . . . . . . . . . . . . . . . . 6 2.1.1 History . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Physics of the solar cell . . . . . . . . . . . . . . . . . . . . . . 9 2.3 I

  11. Reaction kinetics of a-CuInSe2 formation from an In2Se3/CuSe bilayer precursor film

    E-Print Network [OSTI]

    Anderson, Timothy J.

    with Ga or S are proven absorber materials for high efficiency thin film solar cells. Interestingly CIGS system using the stacked elemental film precursors (e.g. glass/Cu/In/Se, glass/Cu/Se, glass

  12. asi tiina kster: Topics by E-print Network

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

    1|19 12;1 IT Ecosystems IT Ecosystems Michael Kster CIG, TU Clausthal Ga Zachmann, Gabriel 12 Asie du Sud : les amateurs-experts de la violence collective Par Laurent...

  13. 2006 Minerals Yearbook U.S. Department of the Interior

    E-Print Network [OSTI]

    ) solar cells that would yield high production throughput. Flexible CIGS solar cells could All refined, produced the majority of indium metal and indium compounds in 2006. A number of small companies produced

  14. ENMA 411: Materials for Energy 2 Lecture: Tuesdays and Thursdays, 9:30 am 10:45 pm EGR 1110

    E-Print Network [OSTI]

    Rubloff, Gary W.

    (including Youtube links) Grading: Homework --- 20% Mid term Exam --- 40% Final Exam --- 40% Course---3 lectures Transparent electrode: 1---2 lecture Si (device and new materials): 2 lectures CZTS, CIGS (device

  15. Reliability Issues for Photovoltaic Modules (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2009-10-01T23:59:59.000Z

    Si modules good in field; new designs need reliability testing. CdTe & CIGS modules sensitive to moisture; carefully seal. CPV in product development stage; benefits from expertise in other industries.

  16. Published: September 21, 2011 r 2011 American Chemical Society 3792 dx.doi.org/10.1021/am201097p |ACS Appl. Mater. Interfaces 2011, 3, 37923795

    E-Print Network [OSTI]

    Various CQD materials, including CdSe,2,3 CdS,4 Cd3P2,5 Si,6 CIGS,7 CZTS,8 PbS,9,10 and PbSe,11,12 have

  17. SMINAIRE DU DPARTEMENT DE GNIE PHYSIQUE Jeudi le 1er

    E-Print Network [OSTI]

    Meunier, Michel

    -ySy (CIGS) and Cu2ZnSnSe4-ySy (CZTS) absorber layers, with resulting device power conversion spectroscopy, leading to a better understanding of factors limiting device performance. For CZTS

  18. The maintenance of a particular redox state ... ... is critical for the proper function of many molecules, including proteins. In their

    E-Print Network [OSTI]

    Raines, Ronald T.

    that a soluble mixed diselenide can catalyze the efficient relay of electrons from an immobilized dithiol­Disulfide Interchange Hot Paper DOI: 10.1002/anie.201307481 Thiols and Selenols as Electron-Relay Catalysts would enable its removal after disulfide reduction by either filtration or centrifugation.[6] To test

  19. PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS Prog. Photovolt: Res. Appl. 2001; 9:211215 (DOI:10.1002/pip.374)

    E-Print Network [OSTI]

    Romeo, Alessandro

    . Polycrystalline compound semiconductor thin-®lm solar cells based on Cu(In,Ga)Se2 (CIGS) and CdTe are known to high-energy irradiation is superior to conventional Si or GaAs solar cells.5±7 CIGS solar cells:211±215 (DOI:10.1002/pip.374) SHORT COMMUNICATION: ACCELERATED PUBLICATION Flexible CdTe Solar Cells on Polymer

  20. Atomic layer deposition of Al-incorporated Zn(O,S) thin films with tunable electrical Helen Hejin Park, Ashwin Jayaraman, Rachel Heasley, Chuanxi Yang, Lauren Hartle, Ravin Mankad, Richard

    E-Print Network [OSTI]

    to the conventional toxic CdS buffer material for CIGS and CZTS solar cells, Zn(O,S) is composed of earth (CBO) at the buffer/absorber interface to optimize the solar cell device performance,13 as illustrated absorber materials, such as Cu(In,Ga)(S,Se)2 (CIGS),1,2 Cu2ZnSn(Se,S)4 (CZTS),3­5 and SnS.6­9 Compared

  1. Electron drift-mobility measurements in polycrystalline CuIn1-xGaxSe2 solar cells

    E-Print Network [OSTI]

    Schiff, Eric A.

    .1063/1.3692165] The chalcopyrite alloys CuIn1ÀxGaxSe2 (CIGS) are the basis of very promising thin film solar cells, with solar con conduction band states.8,9 Empirical optimization of CIGS for solar cells thus appears to have led to lowElectron drift-mobility measurements in polycrystalline CuIn1-xGaxSe2 solar cells S. A. Dinca, E. A

  2. Device modeling and simulation of the performance of Cu(In1x,Gax)Se2 solar cells

    E-Print Network [OSTI]

    Anderson, Timothy J.

    on the simulation results, an optimal graded band-gap structure for the CIGS solar cell is proposed. The performance-junction Cu(In1Àx,Gax)Se2 (CIGS) solar cells. Increasing the open-circuit voltage (Voc) to improve the overallDevice modeling and simulation of the performance of Cu(In1Àx,Gax)Se2 solar cells Jiyon Song

  3. UncorrectedProof PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS

    E-Print Network [OSTI]

    Sites, James R.

    in Evaporated and Selenized CIGS(S) Solar Cells P. K. Johnson1 *,y , J. T. Heath2z , J. D. Cohen2 , K John Wiley & Sons, Ltd. key words: CIGS(S); solar cells; defects; carrier density; AS; DLCP-level capacitance profiling mea- surements were taken on Cu(In1ÀxGax)(Se1ÀySy)2 solar cell devices. The devices were

  4. Research on polycrystalline thin-film CuGaInSe{sub 2} solar cells. Annual subcontract report, 3 May 1991--2 May 1992

    SciTech Connect (OSTI)

    Stanbery, B.J.; Chen, W.S.; Devaney, W.E.; Stewart, J.W. [Boeing Co., Seattle, WA (United States). Defense and Space Systems Group

    1992-11-01T23:59:59.000Z

    This report describes research to fabricate high-efficiency CdZnS/CuInGaSe{sub 2} (CIGS) thin-film solar cells, and to develop improved transparent conductor window layers such as ZnO. A specific technical milestone was the demonstration of an air mass (AM) 1.5 global, 13% efficient, 1-cm{sup 2}-total-area CIGS thin-film solar cell. Our activities focused on three areas. First, a CIGS deposition: system was modified to double its substrate capacity, thus increasing throughput, which is critical to speeding the process development by providing multiple substrates from the same CIGS run. Second, new tooling was developed to enable an investigation of a modified aqueous CdZnS process. The goal was to improve the yield of this critical step in the device fabrication process. Third, our ZnO sputtering system was upgraded to improve its reliability, and the sputtering parameters were further optimized to improve its properties as a transparent conducting oxide. The characterization of the new CIGS deposition system substrate fixturing was completed, and we produced good thermal uniformity and adequately high temperatures for device-quality CIGS deposition. Both the CIGS and ZnO deposition processes were refined to yield a ZnO//Cd{sub 0.82}Zn{sub 0.18}S/CuIn{sub 0.80}Ga{sub 0.20}Se{sub 2} cell that was verified at NREL under standard testing conditions at 13.1% efficiency with V{sub oc} = 0.581 V, J{sub sc} = 34.8 mA/cm{sup 2}, FF = 0.728, and a cell area of 0.979 cm{sup 2}.

  5. Determination of the retention function of [superscript 67]Ga in canine

    E-Print Network [OSTI]

    Schoenbucher, Bruce

    1982-01-01T23:59:59.000Z

    ABSTRACT . . . ~ ACKNOWLEDGEMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES INTRODUCTION LITERATURE REVIEW vi vii viii 3 History Gallium Kinetics Physical Properties of 67Ga METHODS AND MATERIAL 3 4 18 21 Research Subjects... their attention to Ga. This isotope of gallium has a longer half-life and its method of production resulted in a carrier-free* prepara- *uCarrier-free" means that the concentration of stable nuclides of gallium in the injectate are below spectrographic...

  6. Structural tuning of residual conductivity in highly mismatched III-V layers

    DOE Patents [OSTI]

    Han, Jung (Albuquerque, NM); Figiel, Jeffrey J. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A new process to control the electrical conductivity of gallium nitride layers grown on a sapphire substrate has been developed. This process is based on initially coating the sapphire substrate with a thin layer of aluminum nitride, then depositing the gallium nitride thereon. This process allows one to controllably produce gallium nitride layers with resistivity varying over as much as 10 orders of magnitude, without requiring the introduction and activation of suitable dopants.

  7. 2012 Solid-State Lighting Manufacturing R&D Workshop Presentations...

    Broader source: Energy.gov (indexed) [DOE]

    Frank Cerio, Veeco Instruments Advanced Epi Tools for Gallium Nitride Light Emitting Diode Devices Vivek Agrawal, Applied Materials Driving Down HB-LED Costs:...

  8. The role of screening of the electron-phonon interaction in relaxation of photoexcited electron-hole plasma in semiconductors

    SciTech Connect (OSTI)

    Kumekov, S. E. [Kazakh National Technical University (Kazakhstan)], E-mail: skumekov@mail.ru

    2008-08-15T23:59:59.000Z

    The role of screening of the interaction of the electron-hole plasma with optical phonons is analytically evaluated by the example of gallium arsenide.

  9. E-Print Network 3.0 - arsenide x-ray imaging Sample Search Results

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

    Physics 4 Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride by metalorganic vapor-phase epitaxy Summary: assessed using high-...

  10. J O U R N A L O F C H E M I S T R Y

    E-Print Network [OSTI]

    Walba, David

    interactions in inhibiting the efficient widescale commercial utilization of polymeric electro for polymeric electro-optic modulators; however, in with devices fabricated from lithium niobate and gallium

  11. Atomistic Study of the Melting Behavior of Single Crystalline...

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

    and 110-oriented lateral facets, respectively. Citation: Wang Z, X Zu, F Gao, and WJ Weber.2007."Atomistic Study of the Melting Behavior of Single Crystalline Wurtzite Gallium...

  12. Synthesis of the Sterically Related Nickel Gallanediyl Complexes [Ni(CO)3(GaAr?)] (Ar? = C6H3-2,6-(C6H3-2,6-iPr2)2) and [Ni(CO)3(GaL)] (L = HC[C(CH3)N(C6H3-2,6-iPr2)]2): Thermal Decomposition of [Ni(CO)3(GaAr?)] to give the Cluster [Ni4(CO)7(GaAr?)3

    E-Print Network [OSTI]

    Serrano, Oracio; Hoppe, Elke; Power, Philip P.

    2010-01-01T23:59:59.000Z

    of the Sterically Related Nickel Gallanediyl Complexesof the Sterically Related Nickel Gallanediyl Complexes [Ni(4. Keywords Gallium Á Nickel Á Steric hindrance Á Carbonyl

  13. THERMODYNAMICS OF SOLID AND LIQUID GROUP III-V ALLOYS

    E-Print Network [OSTI]

    Anderson, T.J.

    2011-01-01T23:59:59.000Z

    a high temperature heat capacity for liquid gallium which isthe molar heat capacity of the stoichiometric liquid and theheat capacity of the supercooled stoichiometric binary liquid

  14. aircraft exhaust plumes: Topics by E-print Network

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

    ocean before descending to the core. We report results of laboratory experiments-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities...

  15. aircraft plume model: Topics by E-print Network

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

    ocean before descending to the core. We report results of laboratory experiments-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities...

  16. ablation plume propagation: Topics by E-print Network

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

    ocean before descending to the core. We report results of laboratory experiments-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities...

  17. ablation plume expansion: Topics by E-print Network

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

    ocean before descending to the core. We report results of laboratory experiments-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities...

  18. ablation plume thermalization: Topics by E-print Network

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

    ocean before descending to the core. We report results of laboratory experiments-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities...

  19. ablation plume dynamics: Topics by E-print Network

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

    ocean before descending to the core. We report results of laboratory experiments-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities...

  20. Recent technological advances in thin film solar cells

    SciTech Connect (OSTI)

    Ullal, H.S.; Zwelbel, K.; Surek, T.

    1990-03-01T23:59:59.000Z

    High-efficiency, low-cost thin film solar cells are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. This paper reviews the substantial advances made by several thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, cadmium telluride, and polycrystalline silicon. Recent examples of utility demonstration projects of these emerging materials are also discussed. 8 refs., 4 figs.

  1. The Buddhist princess and the woolly turban: non-Buddhist others in a 15th century biography

    E-Print Network [OSTI]

    Diemberger, Hildegard

    2008-01-01T23:59:59.000Z

    of this family is described in the Shel dkar chos ‘byung (folio 4a- 8a). 7 De’i tshe na ‘jig rten la grags pa ltar du sa spyod tshe dbang bkra shis kyi tshem che dkar po cig ‘khor gsum gshen rabs kyi sgrol zhwa cig rnam gsung pa so nams khyer te/ sgo mangs... -in-law is extremely beautiful and has great power and honor (dbu 'phang mtho)!” Later she heard this and thought: ‘This is a good omen!’ (rten ‘brel)! (folio 16a-17a)10 8 These turquoise cloaks were possibly similar...

  2. This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE JOURNAL OF PHOTOVOLTAICS 1

    E-Print Network [OSTI]

    Atwater, Harry

    as presented, with the exception of pagination. IEEE JOURNAL OF PHOTOVOLTAICS 1 Gallium Arsenide Solar Cell--Gallium arsenide, nanospheres, photovoltaic systems, whispering gallery modes (WGMs). I. INTRODUCTION THE route as the active layer is thinned [2]. Thin-film photovoltaics offer the possibility to significantly reduce

  3. CX-010895: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Development and Industrialization of Indium Gallium Nitride/Gallium Nitride (InGaN/GaN) Light Emitting Diodes LEDs on Patterned Sapphire Substrate (PSS) for Low Cost Emitter Architecture CX(s) Applied: B3.6 Date: 06/27/2013 Location(s): California Offices(s): National Energy Technology Laboratory

  4. TESLA-FEL 2007-03 Application of low cost GaAs LED as neutron

    E-Print Network [OSTI]

    neutrons in unbiased Gallium Arsenide (GaAs) Light Emitting Diodes (LED) resulted in a reduction Keywords: COTS components, Displacement damage, Electron Linear Accelerator, GaAs Light emitting diode (LED) Gallium Arsenide (GaAs) light emitting diode (LED) for the assessment of integrated neutron fluence

  5. A. M. Khounsa ry, T. M. Kuz ay and G. A. Forster

    E-Print Network [OSTI]

    Kemner, Ken

    -channel, gallium-cooled Cornell silicon crystal is evaluated for the given system configuration and specifica tions crystals. These crystals are cooled by water or gallium. In addition, the IR data obtained in the CHESS was found. We then began to investigate the reliability of the supplied IR measurements. One of the authors

  6. innovati nNREL Scientists Spurred the Success of Multijunction Solar Cells

    E-Print Network [OSTI]

    innovati nNREL Scientists Spurred the Success of Multijunction Solar Cells Before 1984, many a solar cell can convert into electricity. Olson thought the focus should change to finding materials-winning gallium indium phosphide/gallium arsenide tandem solar cell, which had achieved record efficiencies, con

  7. Anomalous nonlinear photoresponse in a InGaNGaN heterostructure J. Zeller,* W. Rudolph, and M. Sheik-Bahae

    E-Print Network [OSTI]

    Sheik-Bahae, Mansoor

    deposition on a c-plane sapphire substrate. A 20 nm thick low-temperature grown GaN buffer layer between the sapphire substrate and the n-GaN layer as well as linear photoconductivity in a Gallium nitride/ Indium-Gallium nitride GaN/InGaN heterostructure

  8. JOURNAL DE PHYSIQUE Colloque C5, supplment au n012, Tome 43, dcembre 1982 page C5-421

    E-Print Network [OSTI]

    Boyer, Edmond

    trois radicaux éthyls par des radicaux méthyls sur l'arsenic favorise la dissociation de la molécule et radicaux éthyls par deux radicaux méthyls sur le gallium renforce l'aci- dité de Lewis du dérivé du gallium les acides de Lewis méthylés tel que GaMe3 sont des meilleurs accepteurs que les dérivés éthylés comme

  9. Transport, Interfaces, and Modeling in Amorphous Silicon Based Solar Cells: Final Technical Report, 11 February 2002 - 30 September 2006

    SciTech Connect (OSTI)

    Schiff, E. A.

    2008-10-01T23:59:59.000Z

    Results for a-Si characteristics/modeling; photocarrier drift mobilities in a-Si;H, ..mu..c-Si:H, CIGS; hole-conducting polymers as p-layer for a-Si and c-Si; IR spectra of p/i and n/i interfaces in a-Si.

  10. Mat. Res. Soc. Symp. Proc. Vol. 668 @ 2001 Materials Research Society Influence of proton irradiation and development of flexible CdTe solar cells on polyimide

    E-Print Network [OSTI]

    Romeo, Alessandro

    power (defined as the ratio of output electrical power to the solar module weight). Thin film solar cells on polymer films can yield more than 2- kW/kg specific power. CIGS solar cells of about 10 to 12 irradiation and development of flexible CdTe solar cells on polyimide A. Romeo, D.L. Bätzner, H. Zogg and A

  11. Solar panels are cost intensive, have limitations with respect to

    E-Print Network [OSTI]

    Langendoen, Koen

    Solar panels are cost intensive, have limitations with respect to where they can be integrated to a building as solar panels on a roof or facades are. Ref. TU Delft OCT-13-022 TU Delft / Valorisation Centre of the window, integrated in the window frames, strip-shaped CIGS PV solar cells convert the light

  12. Prof M. Leite, mleite@umd.edu, 2123 CHE Building, 301-405-0231 Department of Materials Science and Engineering

    E-Print Network [OSTI]

    Rubloff, Gary W.

    (transport in semiconductors) Solar cell operation Solar cell design (introduction to simulation) PV technologies: Monocrystalline solar cells, III-V, III-nitrides, Thin-films a-Si, CdTe, CIGS, Light trapping/down conversion, hot-carrier cells Organic PV Characterization: IV, electrical measurements, optical, lifetime

  13. Fast Approximate Convex Decomposition

    E-Print Network [OSTI]

    Ghosh, Mukulika

    2012-10-19T23:59:59.000Z

    : D(M) = Mij[iMi = Mand 8i 6=jM i \\M j = ; (3.1) where M i is the open set of Mi, i.e.,Mi excluding its boundary. De nition .2 The cuts fCig in a decomposition D of a model M , are the maxi- mal boundaries of the components Mi...

  14. Proc. of the 24th IEEE Photovoltaic Specialists Conference (IEEE, New York, 1995), pp. 291-294. ADMITTANCE MEASUREMENTS ON Cu(In,Ga)Se2 POLYCRYSTALLINE THIN-

    E-Print Network [OSTI]

    Scofield, John H.

    for approximately 30 CIS and CIGS polycrystalline thin film solar cells having efficiencies of 12% or better-294. ADMITTANCE MEASUREMENTS ON Cu(In,Ga)Se2 POLYCRYSTALLINE THIN- FILM SOLAR CELLS John H. Scofield Physics-16.4% efficient, 0.43 cm2 area, polycrystalline, thin-film solar cells solar cells from 16 different CuInSe2 (CIS

  15. 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

  16. EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Ceder, Gerbrand

    materials for thin film solar cells such as CdTe and CIGS suffer from concerns over resource scarcity (eEARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS Yun Seog Lee 1 conversion efficiencies should be increased. In terms of reducing module cost, thin film solar cells

  17. LBIC ANALYSIS OF THIN-FILM POLYCRYSTALLINE SOLAR CELLS James R. Sites and Timothy J. Nagle

    E-Print Network [OSTI]

    Sites, James R.

    -film polycrystalline solar cells, such as CdTe and CIGS, and the overall performance of these cells. LBIC is uniquelyLBIC ANALYSIS OF THIN-FILM POLYCRYSTALLINE SOLAR CELLS James R. Sites and Timothy J. Nagle Physics response map, was developed and used to map defects in thin-film solar cells [4]. Improvements to the two

  18. Band-gap grading in Cu(In,Ga)Se2 solar cells M. Gloeckler and J. R. Sites

    E-Print Network [OSTI]

    Sites, James R.

    Band-gap grading in Cu(In,Ga)Se2 solar cells M. Gloeckler and J. R. Sites Department of Physics solar cells, and some researchers have asserted that these fields can enhance performance to show that (1) there can be a beneficial effect of grading, (2) in standard thick- ness CIGS cells

  19. Characterization of CdS thin films grown by chemical bath deposition using four different cadmium sources

    E-Print Network [OSTI]

    Chow, Lee

    efficiency thin film solar cells based on CdTe and Cu(In,Ga)Se2 (CIGS) [3,4]. It has also been used in other used in solar cell applications [6,7]. Deposition of CdS using CBD is based on the slow release of Cd2

  20. Transmittance from visible to mid infra-red in AZO films grown by atomic layer deposition system

    E-Print Network [OSTI]

    Tanner, David B.

    found applications in thin film photovoltaics such as CdTe and CIGS based solar cells (Dhere et al for solar cells, flat panel displays, LCD electrodes, touch panel transparent contacts and IR win- dows Westgate a , D.I. Koukis b , D.J. Arenas c , D.B. Tanner b a Center for Autonomous Solar Power, Binghamton

  1. Electrodeposition of CuGaSe2 from Thiocyanate-Containing Electrolytes

    E-Print Network [OSTI]

    Suni, Ian Ivar

    . Manuscript received September 8, 2010. Published December 2, 2010. CuInxGa1-xSe2 CIGS thin film solar cells- nation velocities.1 Thin film solar cells promise significant economic benefits, because the optical, electrochemical deposition methods may be significantly less expensive for scale-up of thin film solar cells,3

  2. 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

  3. 917wileyonlinelibrary.com www.MaterialsViews.com

    E-Print Network [OSTI]

    the spatial location of performance-limiting recombination in CQD solar cells, and take steps to remedy reported interface loss mechanism in dye sensitized solar cells.[11­13] Recombination at absorber avenue to improving performance. CIGS[4,5] and organic photovoltaics[6,7] have both benefited from

  4. Hole drift mobility measurements in polycrystalline CuIn1-xGaxSe2 S. A. Dinca and E. A. Schiff

    E-Print Network [OSTI]

    Schiff, Eric A.

    mobility measurements on polycrystalline CuIn1-xGaxSe2 CIGS thin films incorporated into solar-cell of these properties is that solar cells fabricated from the thin- film polycrystalline materials have larger in a depletion region at the top interface with cadmium sulfide. 12 cells, originating in two laboratories, were

  5. STRUCTURAL AND OPTOELECTRONIC PROPERTIES OF SYNTHESIZED CuInSe2 NANOPARTICLES

    E-Print Network [OSTI]

    Anderson, Timothy J.

    is one of the promising light absorbing materials for hetero-junction solar cells and is used as a photon absorber in thin-film solar cells [1]. The conversion efficiency of 19.9% has been reported by multisource for formation of CIS compounds. The device performance of CIGS is strongly dependent on both doping and traps

  6. Solar Cells in 2009 and Beyond Mike McGehee

    E-Print Network [OSTI]

    McGehee, Michael

    ;Inorganic Thin Film Solar Cells CdTe CIGS (CuInGaSe2) amorphous Si · A thin film of semiconductorSolar Cells in 2009 and Beyond Mike McGehee Materials Science and Engineering These slides parity cost depends on location #12;Conventional p-n junction photovoltaic (solar) cell #12;Efficiency

  7. The effect of Na in polycrystalline and epitaxial single-crystal CuIn1xGaxSe2

    E-Print Network [OSTI]

    Rockett, Angus

    online 15 December 2004 Abstract Na is found to improve the performance of Cu(In,Ga)Se2 (CIGS) solar the highest efficiency, exceeding 19%, of any thin film polycrystalline solar cell [1]. The diodes work well cells although the mechanism is not clear. This paper briefly reviews some of the observations on Na

  8. Synthesis and Phase Transformation of In2Se3 and CuInSe2 Nanowires Hailin Peng, David T. Schoen, Stefan Meister, Xiao Feng Zhang, and Yi Cui*,

    E-Print Network [OSTI]

    Cui, Yi

    pathways without deadends, which is an advantage over the random p-n junctions. Therefore, NW solar cells10 films of CuInxGa1-xSe2 (CIGS) have been demon- strated to have a high-power efficiency of 19.2%,4 which

  9. Semiconductor Nanowire Optical Antenna Solar Absorbers

    E-Print Network [OSTI]

    Fan, Shanhui

    a clear, intuitive guidance for the design of efficient NW solar cells. The presented approach technology. KEYWORDS Solar cell, semiconductor nanowires, optical antennas, photon management, light trapping employing non-earth-abundant elements like indium (CuInGaSe or CIGS cells) or tellurium (CdTe cells

  10. Investigation of defect properties in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy

    E-Print Network [OSTI]

    Anderson, Timothy J.

    mechanisms (and hence the minority-carrier lifetimes) in CIGS solar cells. Zhang [1] has calculatedInvestigation of defect properties in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy cells. Three solar cells developed using different absorber growth technologies were analyzed using DLTS

  11. Universality of non-Ohmic shunt leakage in thin-film solar cells S. Dongaonkar,1,a

    E-Print Network [OSTI]

    Alam, Muhammad A.

    Universality of non-Ohmic shunt leakage in thin-film solar cells S. Dongaonkar,1,a J. D. Servaites thin-film solar cell types: hydrogenated amorphous silicon a-Si:H p-i-n cells, organic bulk heterojunction BHJ cells, and Cu In,Ga Se2 CIGS cells. All three device types exhibit a significant shunt leakage

  12. The Effects of Non-Uniform Electronic Properties on Thin Film Photovoltaics

    E-Print Network [OSTI]

    Brown, Gregory Ferguson

    2011-01-01T23:59:59.000Z

    Photovoltaics     There  are  two  requirements  for  designing  a  high  efficiency  photovoltaics.    These   modeling  efforts  are  important  not  only  for  future  efficiency  photovoltaics,  typically  made  with  CIGS  and  CdTe   absorber  layers,  are  promising  sources  of  renewable  energy  due  to  their  high   efficiencies  (

  13. The Center for integrative genomics

    E-Print Network [OSTI]

    Kaessmann, Henrik

    The Center for integrative genomics Report 2005­2006 #12;Presentation Director's message 4 Scientific advisory committee 6 Organigram of the CIG 7 research The structure and function of genomes and their evolution alexandrereymond ­ Genome structure and expression 10 henrikKaessmann ­ Evolutionary genomics 12

  14. Hole transport and doping states in epitaxial CuIn1 xGaxSe2 David J. Schroeder

    E-Print Network [OSTI]

    Rockett, Angus

    interest in renewable energy sources such as photovoltaic devices. CuIn1 xGaxSe2 CIGS /CdS hetero- junction there is no evidence of any degradation of performance in these devices.1­5 In light of the current belief in the Cu

  15. EECE 577 Assignment 2 Due date: October 20, at the beginning of class.

    E-Print Network [OSTI]

    Pulfrey, David L.

    investigated for use in low-cost, thin-film solar cells (see, for example, Nanosolar's web-site). CIGS can be p-doped by vacancies, and is used in conjunction with n-CdS to form a heterojunction solar cell. In this assignment

  16. Solar Energy Materials & Solar Cells 88 (2005) 6573 Investigation of pulsed non-melt laser annealing

    E-Print Network [OSTI]

    Anderson, Timothy J.

    Solar Energy Materials & Solar Cells 88 (2005) 65­73 Investigation of pulsed non-melt laser annealing on the film properties and performance of Cu(In,Ga)Se2 solar cells Xuege Wanga , Sheng S. Lia,�, C time to modify near- surface defects and related junction properties in Cu(In,Ga)Se2 (CIGS) solar cells

  17. Isolated Galaxies and Isolated Satellite Systems

    E-Print Network [OSTI]

    Ann, H B; Choi, Yun-Young

    2009-01-01T23:59:59.000Z

    We search for isolated galaxies using a volume-limited sample of galaxies with 0.02r_{vir,nei} and \\rho <\\bar{\\rho} well segregates the CIG galaxies. We confirm the morphology conformity between the host and their satellites, which suggests importance of hydrodynamic interaction among galaxies within their virial radii in galaxy evolution.

  18. DOE 2003 Program Review Hawaii Natural Energy Institute

    E-Print Network [OSTI]

    DOE 2003 Program Review Hawaii Natural Energy Institute School of Ocean&Earth ScienceHydrogen Production Eric L.Miller Richard E. Rocheleau ACKNOWLEDGEMENTS -U.S. Department of Energy for continued.)catalyst films CIS, CIGS iron-oxideelectrochemical metal oxide semiconductor films tungsten trioxide titanium

  19. 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim7020 www.advmat.de

    E-Print Network [OSTI]

    McGehee, Michael

    generation high efficiency photovoltaic architectures, such as photovoltaics with up-converting absorbers[4 conventional inorganic photovoltaic, such as silicon or CuInxGa(1-x)Se2 (CIGS), to form a higher efficiency for Third Generation Photovoltaics Zach M. Beiley, M. Greyson Christoforo, Paul Gratia, Andrea R. Bowring

  20. Nanostructured columnar heterostructures of TiO2 and Cu2O enabled by a thin-film self-assembly approach: Potential for photovoltaics

    E-Print Network [OSTI]

    Pennycook, Steve

    -assembly approach: Potential for photovoltaics O¨ zgu¨ r Polat a,b,1 , Tolga Aytug a, *, Andrew R. Lupini a , Parans vertical oxide heterostructures for photovoltaic applica- tions. Rather, in recent years the development silicon technologies. Presently, CIGS has demonstrated the highest lab-scale cell efficiency at 19.9% [3

  1. 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 www.advmat.de

    E-Print Network [OSTI]

    McGehee, Michael

    generation high efficiency photovoltaic architectures, such as photovoltaics with up-converting absorbers[4 conventional inorganic photovoltaic, such as silicon or CuInxGa(1-x)Se2 (CIGS), to form a higher efficiency for Third Generation Photovoltaics Zach M. Beiley, M. Greyson Christoforo, Paul Gratia, Andrea R. Bowring

  2. Building Integrated Photovoltaics: New trends and Challenges'

    E-Print Network [OSTI]

    Painter, Kevin

    AR coating p-type Si Monocrystalline Silicon solar cell Polycrystalline wafer solar cells #12;· Thin crystalline silicon (mono & multi) Dye cell and organic thin film: a-Si, CdTe, CIGS new concepts the optical absorption in thin a-Si layers, texturing of TCO and reflecting mirror are applied Amorphous

  3. "ECS Transactions -Boston, MA" Volume 16, "Photovoltaics for the 21st Century 7" to be published in September, 2011

    E-Print Network [OSTI]

    Dagenais, Mario

    "ECS Transactions - Boston, MA" Volume 16, "Photovoltaics for the 21st Century 7" to be published Ã?/600 Ã? /200 Ã?. The CIGS film with homogeneous and dense surface morphology with large grain size temperature from 99.99% pure source. Figure 1(a) shows the schematic of the E-beam evaporation system used

  4. International Conference on Advanced Materials: Cancun 2001 Design Considerations for a Hybrid AmorphousDesign Considerations for a Hybrid Amorphous

    E-Print Network [OSTI]

    electrical/optical/electrochemical modeling ­ Triple junction amorphous silicon encapsulated photoelectrodes ­ Triple junction CIGS encapsulated photoelectrodes Hybrid Solid-State/Photoelectrochemical H2 Electrodes and system losses for water-splitting. Efficiency ·Solar to hydrogen efficiency: ·D.O.E. goal of 10% at AM 1

  5. Degradation of transparent conductive oxides; Mechanistic insights across configurations and exposures

    E-Print Network [OSTI]

    Rollins, Andrew M.

    . An encapsulated configuration study was conducted on ITO and AZO, exposing samples to the above accel- erated applications, durability concerns arise. The cost and reliability of solar power are often cited as a primary been reported in thin film silicon solar modules123 , CIGS modules456 and OPV technologies78910

  6. Intermixing at the absorber-buffer layer interface in thin-film solar cells: The electronic effects of point defects in Cu(In,Ga)(Se,S){sub 2} and Cu{sub 2}ZnSn(Se,S){sub 4} devices

    SciTech Connect (OSTI)

    Varley, J. B.; Lordi, V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-08-14T23:59:59.000Z

    We investigate point defects in the buffer layers CdS and ZnS that may arise from intermixing with Cu(In,Ga)(S,Se){sub 2} (CIGS) or Cu{sub 2}ZnSn(S,Se){sub 4} (CZTS) absorber layers in thin-film photovoltaics. Using hybrid functional calculations, we characterize the electrical and optical behavior of Cu, In, Ga, Se, Sn, Zn, Na, and K impurities in the buffer. We find that In and Ga substituted on the cation site act as shallow donors in CdS and tend to enhance the prevailing n-type conductivity at the interface facilitated by Cd incorporation in CIGS, whereas they are deep donors in ZnS and will be less effective dopants. Substitutional In and Ga can favorably form complexes with cation vacancies (A-centers) which may contribute to the “red kink” effect observed in some CIGS-based devices. For CZTS absorbers, we find that Zn and Sn defects substituting on the buffer cation site are electrically inactive in n-type buffers and will not supplement the donor doping at the interface as in CIGS/CdS or ZnS devices. Sn may also preferentially incorporate on the S site as a deep acceptor in n-type ZnS, which suggests possible concerns with absorber-related interfacial compensation in CZTS devices with ZnS-derived buffers. Cu, Na, and K impurities are found to all have the same qualitative behavior, most favorably acting as compensating acceptors when substituting on the cation site. Our results suggest one beneficial role of K and Na incorporation in CIGS or CZTS devices is the partial passivation of vacancy-related centers in CdS and ZnS buffers, rendering them less effective interfacial hole traps and recombination centers.

  7. Investigations of CuInSe sub 2 thin films and contacts

    SciTech Connect (OSTI)

    Nicolet, M.A. (California Inst. of Tech., Pasadena, CA (United States))

    1991-10-01T23:59:59.000Z

    This report describes research into electrical contacts for copper indium diselenide (CuInSe{sub 2}) polycrystalline thin films used for solar cell applications. Molybdenum contacts have historically been the most promising for heterojunction solar cells. This program studied contact stability by investigating thermally induced bilayer reactions between molybdenum and copper, indium, and selenium. Because selenization is widely used to fabricate CuInSe{sub 2} thin films for photovoltaic cells, a second part of the program investigated how the morphologies, phases, and reactions of pre-selenization Cu-In structures are affected by the deposition process and heat treatments. 7 refs., 6 figs.

  8. Device-level thermal analysis of GaN-based electronics

    E-Print Network [OSTI]

    Bagnall, Kevin Robert

    2013-01-01T23:59:59.000Z

    Gallium nitride (GaN)-based microelectronics are one of the most exciting semiconductor technologies for high power density and high frequency electronics. The excellent electrical properties of GaN and its related alloys ...

  9. CX-004937: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Transphorm, Inc. -High Performance Gallium Nitride High Electron Mobility Transistor Modules for Agile Power ElectronicsCX(s) Applied: B3.6Date: 08/05/2010Location(s): CaliforniaOffice(s): Advanced Research Projects Agency - Energy

  10. A compact transport and charge model for GaN-based high electron mobility transistors for RF applications

    E-Print Network [OSTI]

    Radhakrishna, Ujwal

    2013-01-01T23:59:59.000Z

    Gallium Nitride (GaN)-based high electron mobility transistors (HEMTs) are rapidly emerging as front-runners in high-power mm-wave circuit applications. For circuit design with current devices and to allow sensible future ...

  11. GaN/Cu[subscript 2]O Heterojunctions for Photovoltaic Applications

    E-Print Network [OSTI]

    Hering, K.P.

    Several growth methods were employed to investigate the photovoltaic behavior of GaN/Cu[subscript 2]O heterojunctions by depositing cuprous oxide thin films on top of gallium nitride templates. The templates consist of a ...

  12. MOCVD growth of In GaP-based heterostructures for light emitting devices

    E-Print Network [OSTI]

    McGill, Lisa Megan, 1975-

    2004-01-01T23:59:59.000Z

    In this work, we examine fundamental materials processes in the growth of indium gallium phosphide (InGaP) via metalorganic chemical vapor deposition (MOCVD). In particular, we realize improvements in the epitaxial integration ...

  13. JOURNAL DE PHYSIQUE Colloque C5, supplment au n 5, Tome 40, Mai 1979, page C5-159 Magnetic properties and phase transitions of RA^Ga^ (R = Tb, Ho)

    E-Print Network [OSTI]

    Boyer, Edmond

    synthesized in an arc furnace in purest argon atmosphere from 99.999 % gallium (Alusuisse), 99.99 % aluminium., Ltd.) and remelted several times. The ingots were enclosed under vacuum in tantalum containers

  14. On the two-dimensionalization of quasi-static MHD turbulence B. Favier,1, a)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in industrial configurations (such as a French fast breeder reactor Superph´enix). Generally, the motion in the laboratory1 . More recent laboratory experiments use sodium or gallium, whereas liquid sodium is used

  15. J. Fluid Mech. (2011), vol. 681, pp. 434461. c Cambridge University Press 2011 doi:10.1017/jfm.2011.207

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2011-01-01T23:59:59.000Z

    ; liquid sodium is also used in industrial configurations, for instance in the French fast breeder reactor) in liquid mercury. Recent laboratory experiments on the dynamics of conducting fluids use sodium or gallium

  16. Calendar | OSTI, US Dept of Energy, Office of Scientific and...

    Office of Scientific and Technical Information (OSTI)

    Application Center 2014-10-16 13:32 Advanced Epi Tools for Gallium Nitride Light Emitting Diode Devices 2014-10-16 13:32 CHEMICAL ANALYSIS OF SIMULATED HIGH LEVEL WASTE...

  17. 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 2749 www.advmat.de

    E-Print Network [OSTI]

    Prentiss, Mara

    . Whitesides* Stretchable Microfluidic Radiofrequency Antennas This paper describes a new method for fabricating stretchable radiofrequency antennas. The antennas consist of liquid metal (eutectic gallium indium be repeatedly stretched, while retaining a high efficiency (> 95 %) in radiation. "Stretchability

  18. Applied Materials Develops an Advanced Epitaxial Growth System to Bring Down LED Costs

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, Applied Materials has developed an advanced epitaxial growth system for gallium nitride (GaN) LED devices that decreases operating costs, increases internal quantum efficiency, and improves binning yields.

  19. CX-010873: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Ammonothermal Bulk Gallium Nitride Crystal Growth for Energy Efficient Lightning and Power Electronics CX(s) Applied: B3.6 Date: 05/22/2013 Location(s): California Offices(s): Advanced Research Projects Agency-Energy

  20. A-15 Superconducting composite wires and a method for making

    DOE Patents [OSTI]

    Suenaga, Masaki (Bellport, NY); Klamut, Carl J. (East Patchogue, NY); Luhman, Thomas S. (Westhampton Beach, NY)

    1984-01-01T23:59:59.000Z

    A method for fabricating superconducting wires wherein a billet of copper containing filaments of niobium or vanadium is rolled to form a strip which is wrapped about a tin-alloy core to form a composite. The alloy is a tin-copper alloy for niobium filaments and a gallium-copper alloy for vanadium filaments. The composite is then drawn down to a desired wire size and heat treated. During the heat treatment process, the tin in the bronze reacts with the niobium to form the superconductor niobium tin. In the case where vanadium is used, the gallium in the gallium bronze reacts with the vanadium to form the superconductor vanadium gallium. This new process eliminates the costly annealing steps, external tin plating and drilling of bronze ingots required in a number of prior art processes.