Sample records for gd2o2s gallium arsenide

  1. 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.

  2. 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.

  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. 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

  5. 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...

  6. 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

  7. 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

  8. 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...

  9. 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...

  10. 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...

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  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. 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

  18. 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.

  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. 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.

  1. 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.

  2. 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-...

  3. 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.

  4. 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...

  5. 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

  6. 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 ...

  7. 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...

  8. A Terminal Molybdenum Arsenide Complex Synthesized from Yellow Arsenic

    E-Print Network [OSTI]

    Curley, John J.

    A terminal molybdenum arsenide complex is synthesized in one step from the reactive As4 molecule. The properties of this complex with its arsenic atom ligand are discussed in relation to the analogous nitride and phosphide ...

  9. 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...

  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

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

  11. 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 /

  12. 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

  13. 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" !

  14. 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...

  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. 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...

  18. 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

  19. 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.

  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

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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. Thermoelectric Properties of Some Cobalt Phosphide-Arsenide Compounds Anucha Watcharapasorn*

    E-Print Network [OSTI]

    Thermoelectric Properties of Some Cobalt Phosphide-Arsenide Compounds Anucha Watcharapasorn been synthesized and their thermoelectric properties measured. All three samples show semiconductingAsx system have also been synthesized and their thermoelectric properties are currently being investigated

  9. 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

  10. 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)

  11. 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.

  12. (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

  13. 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...

  14. 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...

  15. 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...

  16. Aluminum arsenide cleaved-edge overgrown quantum wires T. Zibold, D. Schuh, M. Bichler, F. Ertl, G. Abstreiter, and M. Grayson

    E-Print Network [OSTI]

    Grayson, Matthew

    Aluminum arsenide cleaved-edge overgrown quantum wires J. Moser,a T. Zibold, D. Schuh, M. Bichler measurements in quantum wires made of aluminum arsenide, a heavy-mass, multivalley one-dimensional 1D system, and G0=2e2 /h was observed in the presence of disorder.3 Aluminum arsenide AlAs is an alternate heavy

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. (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

  2. (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

  3. Iron Arsenides--The New Family of High TC Magnetic Superconductors

    E-Print Network [OSTI]

    Weston, Ken

    Iron Arsenides--The New Family of High TC Magnetic Superconductors Jeff Lynn NIST Center Superconductors · (Brief) History of Magnetic Superconductors ­ Magnetic Impurities ­ Long Range Magnetic Order: Coexistence and Competition · Cuprate Superconductors--Highly Correlated Electron Systems ­ Undoped systems

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. (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

  12. 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.

  13. High Pressure X-ray Diffraction Study on Icosahedral Boron Arsenide (B12As2)

    SciTech Connect (OSTI)

    J Wu; H Zhu; D Hou; C Ji; C Whiteley; J Edgar; Y Ma

    2011-12-31T23:59:59.000Z

    The high pressure properties of icosahedral boron arsenide (B12As2) were studied by in situ X-ray diffraction measurements at pressures up to 25.5 GPa at room temperature. B12As2 retains its rhombohedral structure; no phase transition was observed in the pressure range. The bulk modulus was determined to be 216 GPa with the pressure derivative 2.2. Anisotropy was observed in the compressibility of B12As2-c-axis was 16.2% more compressible than a-axis. The boron icosahedron plays a dominant role in the compressibility of boron-rich compounds.

  14. 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

  15. 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.

  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

    film photovoltaics [1]. This roughly doubling of efficiencyMJ photovoltaics. MJ solar cells achieve higher efficiencies

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Thermal Conductivity and Seebeck Coefficients of Icosahedral Boron Arsenide Films on Silicon Carbide

    SciTech Connect (OSTI)

    Y Gong; Y Zhang; M Dudley; Y Zhang; J Edgar; P Heard; M Kuball

    2011-12-31T23:59:59.000Z

    The thermal conductivity of icosahedral boron arsenide (B{sub 12}As{sub 2}) films grown on (0001) 6H-SiC substrates by chemical vapor deposition was studied by the 3{omega} technique. The room temperature thermal conductivity decreased from 27.0 to 15.3 W/m K as the growth temperature was decreased from 1450 to 1275 C. This is mainly attributed to the differences in the impurity concentration and microstructure, determined from secondary ion mass spectrometry and high resolution transmission electron microscopy, respectively. Callaway's theory was applied to calculate the temperature-dependent thermal conductivity, and the results are in good agreement with the experimental data. Seebeck coefficients were determined as 107 {micro}V/K and 136 {micro}V/K for samples grown at 1350 C with AsH{sub 3}/B{sub 2}H{sub 6} flow ratio equals to 1:1 and 3:5, respectively.

  5. Lattice distortion in single crystal rare-earth arsenide/GaAs nanocomposites

    SciTech Connect (OSTI)

    Young, A. J. [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States); Schultz, B. D. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106-9560 (United States); Palmstrøm, C. J., E-mail: cpalmstrom@ece.ucsb.edu [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States); Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106-9560 (United States)

    2014-02-17T23:59:59.000Z

    Epitaxial single crystal nanocomposites comprised of rare-earth arsenide nanoparticles embedded in GaAs (001) layers produce a larger change in lattice parameter than expected from the lattice parameters of relaxed films. Despite similar cubic structures and lattice parameters, elongation of the interfacial bond length between the two materials induces additional strain causing an expansion in the nanocomposite lattice. The interface bond length is material dependent with an average atomic layer spacing at the ErAs:GaAs interface of 1.9?Å while the spacing at the ScAs:GaAs interface is only 1.4?Å. Implications for lattice matching various single crystal epitaxial nanostructures in semiconductors are discussed.

  6. The Coefficients of Thermal Expansion of Boron Arsenide (B12As2) Between 25 C and 850 C

    SciTech Connect (OSTI)

    Whiteley, Clinton E. [Kansas State University; Kirkham, Melanie J [ORNL; Edgar, J H [Kansas State University

    2013-01-01T23:59:59.000Z

    The semiconductor boron arsenide has a high 10B density, a wide bandgap, and a high melting temperature, all of which make it an interesting candidate for high-temperature electronic devices and radiation detectors. The present investigation was undertaken to determine the coefficients of thermal expansion for boron arsenide. B12As2 powder was synthesized from boron and arsenic heated in a sealed quartz ampoule at 1100 C for 72 hrs with excess boron. Using high temperature X-ray diffraction (HTXRD) between 25 C and 850 C, the average lattice coefficients of thermal expansion were measured perpendicular and parallel to the <111> axis in the rhombohedral setting (equivalent to the a and c axes in the hexagonal setting): 4.9x10-6 K-1 and 5.3x10-6 K-1, respectively. The average unit cell volumetric coefficient of thermal expansion was determined to be 1.5x10-5 K-1.

  7. In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals

    SciTech Connect (OSTI)

    Fisher, Ian Randal

    2012-05-08T23:59:59.000Z

    The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Neel transition is either preceded or accompanied by a structural transition that breaks the four fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an Ising nematic phase transition. Understanding the origin of this effect is a key component of a complete theoretical description of the occurrence of superconductivity in this family of compounds, motivating both theoretical and experimental investigation of the nematic transition and the associated in-plane anisotropy. Here we review recent experimental progress in determining the intrinsic in-plane electronic anisotropy as revealed by resistivity, reflectivity and ARPES measurements of detwinned single crystals of underdoped Fe arsenide superconductors in the '122' family of compounds.

  8. 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.

  9. 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.

  10. (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

  11. (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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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).

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. (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

  9. (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

  10. (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.

  11. (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.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. Synthesis, Structures, and Magnetic Properties of Rare-Earth Cobalt Arsenides, RCo2As2 (R = La, Ce, Pr, Nd)

    SciTech Connect (OSTI)

    Thompson, Corey [Florida State University, Tallahassee] [Florida State University, Tallahassee; Tan, Xiaoyan [Florida State University, Tallahassee] [Florida State University, Tallahassee; Kovnir, Kirill [Florida State University, Tallahassee] [Florida State University, Tallahassee; Garlea, Vasile O [ORNL] [ORNL; Shatruk, Michael [Florida State University, Tallahassee] [Florida State University, Tallahassee

    2014-01-01T23:59:59.000Z

    Four rare-earth cobalt arsenides, RCo2As2 (R = La, Ce, Pr, Nd), were obtained by reactions of constituent elements in molten Bi. The use of Bi flux also allowed the growth of representative single crystals. All compounds are isostructural and belong to the ThCr2Si2 structure type (space group I4/mmm). The formation of Co vacancies is observed in all structures, while the structures of La- and Ce-containing compounds also show incorporation of minor Bi defects next to the R crystallographic site. Correspondingly, the general formula of these materials can be written as R1 xBixCo2 As2, with x/ = 0.03/0.1, 0.05/0.15, 0/0.2, and 0/0.3 for R = La, Ce, Pr, and Nd, respectively. All compounds exhibit high-temperature ferromagnetic ordering of Co magnetic moments in the range of 150-200 K. Electronic band structure calculations revealed a high peak in the density of states at the Fermi level, thus supporting the itinerant nature of magnetism in the Co sublattice. The magnetic ordering in the lanthanide sublattice takes place at lower temperatures, with the R moments aligning antiparallel to the Co moments to give a ferrimagnetic ground state. The measurements on oriented single crystals demonstrated significant magnetic anisotropy in the ferrimagnetic state, with the preferred moment alignment along the c axis of the tetragonal lattice. Neutron powder diffraction failed to reveal the structure of magnetically ordered states, but confirmed the presence of Co vacancies. X-ray absorption near-edge structure spectroscopy on Ce1.95Bi0.05Co1.85As2 showed the average oxidation state of Ce to be +3.06. Solid state NMR spectroscopy revealed a substantially reduced hyperfine field on the Co atoms in the vicinity of Bi defects.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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 ...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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)

  18. 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.

  19. (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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Test vehicle detector characterization system for the Boeing YAL-1 airborne laser

    E-Print Network [OSTI]

    Steininger-Holmes, Jason Thomas

    2008-01-01T23:59:59.000Z

    The test vehicle detector characterization system provides a convenient and efficient tool for rapidly evaluating the optical sensitivity of the GAP6012, GAP100, GAP300, and GAP1000 indium gallium arsenide detectors used ...

  9. Photo: D. Stevenson and C. Conway/Beckman Institute/University of Illinois An inorganic LED display printed on a flexible substrate bends without breaking

    E-Print Network [OSTI]

    Rogers, John A.

    by the Ford Motor Co., which envisions many possible automotive applications for thin, flexible lighting this atop a layer of aluminum arsenide which itself coated a gallium arsenide substrate. Using a combination, such displays would be almost completely transparent--and well suited for another automotive need: inexpensive

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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 %.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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).

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Simple intrinsic defects in GaAs : numerical supplement.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2012-04-01T23:59:59.000Z

    This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

  12. Low dimensional GaAs/air vertical microcavity lasers

    SciTech Connect (OSTI)

    Gessler, J.; Steinl, T.; Fischer, J.; Höfling, S.; Schneider, C.; Kamp, M. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); Mika, A.; S?k, G.; Misiewicz, J. [Institute of Physics, Wroclaw University of Technology, Wybrze?e Wyspia?skiego 27, 50-370 Wroc?aw (Poland)

    2014-02-24T23:59:59.000Z

    We report on the fabrication of gallium arsenide (GaAs)/air distributed Bragg reflector microresonators with indium gallium arsenide quantum wells. The structures are studied via momentum resolved photoluminescence spectroscopy which allows us to investigate a pronounced optical mode quantization of the photonic dispersion. We can extract a length parameter from these quantized states whose upper limit can be connected to the lateral physical extension of the microcavity via analytical calculations. Laser emission from our microcavity under optical pumping is observed in power dependent investigations.

  13. 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.

  14. Preliminary materials assessment for the Satellite Power System (SPS)

    SciTech Connect (OSTI)

    Teeter, R.R.; Jamieson, W.M.

    1980-01-01T23:59:59.000Z

    Presently, there are two SPS reference design concepts (one using silicon solar cells; the other using gallium arsenide solar cells). A materials assessment of both systems was performed based on the materials lists set forth in the DOE/NASA SPS Reference System Report: Concept Development and Evaluation Program. This listing identified 22 materials (plus miscellaneous and organics) used in the SPS. Tracing the production processes for these 22 materials, a total demand for over 20 different bulk materials (copper, silicon, sulfuric acid, etc.) and nealy 30 raw materials (copper ore, sand, sulfur ore, etc.) was revealed. Assessment of these SPS material requirements produced a number of potential material supply problems. The more serious problems are those associated with the solar cell materials (gallium, gallium arsenide, sapphire, and solar grade silicon), and the graphite fiber required for the satellite structure and space construction facilities. In general, the gallium arsenide SPS option exhibits more serious problems than the silicon option, possibly because gallium arsenide technology is not as well developed as that for silicon. Results are presented and discussed in detail. (WHK)

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. IEEE ELECTRON DEVICE LETTERS, VOL. 24, NO. 4, APRIL 2003 227 RF MEMS Switches Fabricated on

    E-Print Network [OSTI]

    Cetiner, Bedri A.

    with superior performance over con- ventional semiconductor devices [4]­[7]. Typically, RF MEMS switches-resistivity silicon wafers, gallium arsenide (GaAs) wafers, and quartz substrates using semiconductor Manuscript and surface planarization of wide metal lines prior to deposition of a metal membrane bridge, which poses

  20. Ab initio cluster calculations of hydrogenated GaAs,,001... surfaces Chemical Engineering Department, University of California, Los Angeles, California 90095-1592

    E-Print Network [OSTI]

    Li, Lian

    Ab initio cluster calculations of hydrogenated GaAs,,001... surfaces Q. Fu Chemical Engineering Engineering Department, University of California, Los Angeles, California 90095-1592 Received 11 November 1999 Hydrogen adsorption on the 2 4 and 4 2 reconstructions of gallium arsenide 001 has been studied by internal

  1. 256 NATURE PHYSICS | VOL 8 | APRIL 2012 | www.nature.com/naturephysics news & views

    E-Print Network [OSTI]

    Loss, Daniel

    resonances, such as the vibrational modes of a suspended beam. Now, Martin Gustafsson and colleagues, writing-state equivalent of ripples on a pond. In piezoelectric materials (such as the gallium arsenide slab used in a radiofrequency- tank circuit, one obtains a so-called radiofrequency SET5 -- an extremely sensitive and fast

  2. Surface Science 415 (1998) 2936 Structural studies of sulfur-passivated GaAs (100)

    E-Print Network [OSTI]

    Zhang, Yanchao

    1998-01-01T23:59:59.000Z

    . Keywords: Atomic force microscopy; Gallium arsenide; Low-energy electron diffraction; Roughness; SulfurSurface Science 415 (1998) 29­36 Structural studies of sulfur-passivated GaAs (100) surfaces Abstract We present the results of Auger electron spectroscopy (AES), low-energy electron diffraction (LEED

  3. Smith chart, where the IRL of the amplifier is constant. The new chart has been added to the constant available gain and constant

    E-Print Network [OSTI]

    Yakovlev, Vadim

    of the proposed design charts has been demonstrated by the design of a narrowband monolithic low-noise amplifier. Streit, MMIC low-noise amplifiers and application above 100 GHZ, 22nd Ann Gallium Arsenide Integrated expressions for simpli- fying the design of broadband low noise microwave transistor amplifi- ers, IEEE Trans

  4. EE Times: Semi News Groups claim breakthroughs in solar cells

    E-Print Network [OSTI]

    Rogers, John A.

    -based, multi-junction solar cells. Module cost is minimized by using high concentration ratio. XEE Times: Semi News Groups claim breakthroughs in solar cells Mark LaPedus Page 1 of 2 EE Times (05 separately claimed breakthroughs in solar cell production. Gallium arsenide (GaAs) and related compounds

  5. GLAS-PPE/2002-16 Department of Physics & Astronomy

    E-Print Network [OSTI]

    Glasgow, University of

    ratio) in semiconductor material here was laser drilling. The main advantages of using a laser is that it is independent of the material drilled (e.g. silicon, gallium arsenide, silicon carbide and CdZnTe) and it is the best technique available currently for GaAs. The drilling operation was carried out at Strathclyde

  6. LED Light Sources for Projection Display Applications

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    LED Light Sources for Projection Display Applications By Chenhui Peng 04-13-2012 #12;Outline · 1. · The first practical LED is in red color and it is made with gallium arsenide (GaAs). 4http://en.wikipedia.org/wiki/Light with holes and release energy in the form of photons. 5http://en.wikipedia.org/wiki/Light-emitting_diode #12

  7. GaAs Nanowire Array Solar Cells with Axial p-i-n Junctions Maoqing Yao, Ningfeng Huang, Sen Cong, Chun-Yung Chi, M. Ashkan Seyedi, Yen-Ting Lin, Yu Cao,

    E-Print Network [OSTI]

    Zhou, Chongwu

    for future low-cost, high-efficiency photovoltaics. KEYWORDS: Nanowires, solar cells, gallium arsenide, axial.58% efficiency. Simulations show that axial junctions are more tolerant to doping variation than radial junctions and shallow junctions are essential for a high extraction efficiency. Our approach opens up great opportunity

  8. IBM Systems and Technology IBM SiGe 5PAe and

    E-Print Network [OSTI]

    IBM Systems and Technology IBM SiGe 5PAe and 1KW5PAe technologies Keep pace with mobile advances SiGe offerings featuring copper pillar and through-silicon-via options Take advantage of ongoing to solutions based on gallium arsenide (GaAs) technology, for example, the IBM SiGe 5PAe family offers several

  9. 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.

  10. A combined kick-out and dissociative diffusion mechanism of grown-in Be in InGaAs and InGaAsP. A new finite difference-Bairstow method for solution of the diffusion equations

    SciTech Connect (OSTI)

    Koumetz, Serge D., E-mail: Serge.Koumetz@univ-rouen.fr; Martin, Patrick; Murray, Hugues [Normandie Université-Université de Rouen-ENSICAEN-UMR 6508 LaMIPS, Laboratoire commun CNRS-NXP-PRESTO-ENSICAEN-UCBN 2, rue de la Girafe BP 5120, F-14079 Caen (France)

    2014-09-14T23:59:59.000Z

    Experimental results on the diffusion of grown-in beryllium (Be) in indium gallium arsenide (In{sub 0.53}Ga{sub 0.47}As) and indium gallium arsenide phosphide (In{sub 0.73}Ga{sub 0.27}As{sub 0.58}P{sub 0.42}) gas source molecular beam epitaxy alloys lattice-matched to indium phosphide (InP) can be successfully explained in terms of a combined kick-out and dissociative diffusion mechanism, involving neutral Be interstitials (Be{sub i}{sup 0}), singly positively charged gallium (Ga), indium (In) self-interstitials (I{sub III}{sup +}) and singly positively charged Ga, In vacancies (V{sub III}{sup +}). A new numerical method of solution to the system of diffusion equations, based on the finite difference approximations and Bairstow's method, is proposed.

  11. 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.

  12. 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.

  13. 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...

  14. The design of a concentrator solar array for use in low earth orbit 

    E-Print Network [OSTI]

    Kish, Guy Leslie

    1990-01-01T23:59:59.000Z

    to satellites. It is designed to utilize the ENTECH Incorporated Fresnel non-spherical dome concentrator lens in conjunction with gallium arsenide solar cells. The solar array structure is composed of aluminum metal matrix composite materials. Production... and manufacturing methods are determined for the aluminum composites and they are shown to be a material from which a satellite structure can be produced. These materials are shown to be compatible with electronic and optical components. Producers...

  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. arsenide photoconductive detectors: Topics by E-print Network

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

    be destructive in some highly energetic cases, at least being responsible of a slow aging of the detector. So far one solution has been cascading several gain elements (GEM,...

  17. arsenide inas quantum: Topics by E-print Network

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

    and Khaled Karraia photoluminescence from self-assembled InAs quantum dots depend on pumping power and vertical electric field. The In of Physics. DOI: 10.10631.1356445...

  18. arsenide superconductors including: Topics by E-print Network

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

    to disfavor standard symmetric BCS pairing and may favor an inhomogeneous color superconducting phase. The properties of inhomogeneous color superconductors are discussed in...

  19. arsenide solar cells: Topics by E-print Network

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

    Pankaj J Edla; Dr. Bhupendra Gupta 92 Fully Solution-Processed Copper Chalcopyrite Thin Film Solar Cells: Materials Chemistry, Processing, and Device Physics University of...

  20. arsenide solar cell: Topics by E-print Network

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

    Pankaj J Edla; Dr. Bhupendra Gupta 92 Fully Solution-Processed Copper Chalcopyrite Thin Film Solar Cells: Materials Chemistry, Processing, and Device Physics University of...

  1. arsenide thin films: Topics by E-print Network

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

    films Engineering Websites Summary: of domain switching and controllability, preventing thin-film and polycrystalline ferroelectrics from the switching mechanisms of...

  2. aluminium arsenide solar cells: Topics by E-print Network

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

    Cells Lecture 6: Solar Cells Solar Cell Technologies A) Crystalline Silicon B) Thin Film C) Group III-IV Cells 2Montana State University: Solar Cells Lecture 6:...

  3. Synthesis and Characterization of Bulk, Vitreous Cadmium Germanium Arsenide

    E-Print Network [OSTI]

    Rockett, Angus

    is presented to enable fabrication of high-purity, vitreous, crack-free ingots with sizes up to 10 mm diameter are the key function material in several important technological areas such as xerography,1 photovoltaics,2 formation within the CdGexAs2 system has been re- ported for x 5 0.02­1.3.12­18 The basic glass forming

  4. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

    Hou, H.Q.; Reinhardt, K.C.

    1999-08-31T23:59:59.000Z

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

  5. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

    Hou, Hong Q. (Albuquerque, NM); Reinhardt, Kitt C. (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

  6. 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

  7. 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.

  8. 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. ...

  9. 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 ...

  10. 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...

  11. 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.

  12. 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 ...

  13. 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

  14. Nanobeam Photonic Crystal Cavity Light-Emitting Diodes

    E-Print Network [OSTI]

    Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

    2011-01-01T23:59:59.000Z

    We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densities possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results open the door for efficient electrical control of active nanobeam cavities for diverse nanophotonic applications.

  15. The development of integrated chemical microsensors in GaAs

    SciTech Connect (OSTI)

    CASALNUOVO,STEPHEN A.; ASON,GREGORY CHARLES; HELLER,EDWIN J.; HIETALA,VINCENT M.; BACA,ALBERT G.; HIETALA,S.L.

    1999-11-01T23:59:59.000Z

    Monolithic, integrated acoustic wave chemical microsensors are being developed on gallium arsenide (GaAs) substrates. With this approach, arrays of microsensors and the high frequency electronic components needed to operate them reside on a single substrate, increasing the range of detectable analytes, reducing overall system size, minimizing systematic errors, and simplifying assembly and packaging. GaAs is employed because it is both piezoelectric, a property required to produce the acoustic wave devices, and a semiconductor with a mature microelectronics fabrication technology. Many aspects of integrated GaAs chemical sensors have been investigated, including: surface acoustic wave (SAW) sensors; monolithic SAW delay line oscillators; GaAs application specific integrated circuits (ASIC) for sensor operation; a hybrid sensor array utilizing these ASICS; and the fully monolithic, integrated SAW array. Details of the design, fabrication, and performance of these devices are discussed. In addition, the ability to produce heteroepitaxial layers of GaAs and aluminum gallium arsenide (AlGaAs) makes possible micromachined membrane sensors with improved sensitivity compared to conventional SAW sensors. Micromachining techniques for fabricating flexural plate wave (FPW) and thickness shear mode (TSM) microsensors on thin GaAs membranes are presented and GaAs FPW delay line and TSM resonator performance is described.

  16. InGaAsN/GaAs heterojunction for multi-junction solar cells

    DOE Patents [OSTI]

    Kurtz, Steven R. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM); Klem, John F. (Albuquerque, NM); Jones, Eric D. (Edgewood, NM)

    2001-01-01T23:59:59.000Z

    An InGaAsN/GaAs semiconductor p-n heterojunction is disclosed for use in forming a 0.95-1.2 eV bandgap photodetector with application for use in high-efficiency multi-junction solar cells. The InGaAsN/GaAs p-n heterojunction is formed by epitaxially growing on a gallium arsenide (GaAs) or germanium (Ge) substrate an n-type indium gallium arsenide nitride (InGaAsN) layer having a semiconductor alloy composition In.sub.x Ga.sub.1-x As.sub.1-y N.sub.y with 070%.

  17. Design, fabrication, and analysis of p-channel arsenide/antimonide hetero-junction tunnel transistors

    SciTech Connect (OSTI)

    Rajamohanan, Bijesh, E-mail: bor5067@psu.edu; Mohata, Dheeraj; Hollander, Matthew; Datta, Suman [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zhu, Yan; Hudait, Mantu [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Jiang, Zhengping; Klimeck, Gerhard [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47906 (United States)

    2014-01-28T23:59:59.000Z

    In this paper, we demonstrate InAs/GaSb hetero-junction (hetJ) and GaSb homo-junction (homJ) p-channel tunneling field effect transistors (pTFET) employing a low temperature atomic layer deposited high-? gate dielectric. HetJ pTFET exhibited drive current of 35 ?A/?m in comparison to homJ pTFET, which exhibited drive current of 0.3 ?A/?m at V{sub DS}?=??0.5?V under DC biasing conditions. Additionally, with pulsing of 1 ?s gate voltage, hetJ pTFET exhibited enhanced drive current of 85 ?A/?m at V{sub DS}?=??0.5?V, which is the highest reported in the category of III-V pTFET. Detailed device characterization was performed through analysis of the capacitance-voltage characteristics, pulsed current-voltage characteristics, and x-ray diffraction studies.

  18. E-Print Network 3.0 - arsenide-zinc selenide core-shell Sample...

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

    as 3D Scaffolds for New Materials: from Mechanically Strong Polymer Crosslinked Aerogels Summary: . Those 3D core-shell superstructures are true multifunctional materials...

  19. arsenide p-i-n detectors: Topics by E-print Network

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

    be destructive in some highly energetic cases, at least being responsible of a slow aging of the detector. So far one solution has been cascading several gain elements (GEM,...

  20. arsenide oxides sr2cro3feas: Topics by E-print Network

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

    gas phase oxidation of alkenes as propene to unsaturated aldehydes or ketones such as acrolein. A 19 Cu20 catalyst was used and periodically reactivated... Billingsley, David...

  1. arsenide junction-field-effect transistors: Topics by E-print...

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

    25 Next Page Last Page Topic Index 201 Proposal and design of a new SiC-emitter lateral NPM Schottky collector bipolar transistor on Engineering Websites Summary: for VLSI...

  2. Magnetism and superconductivi[t]y in Pr-based filled skutterudite arsenides

    E-Print Network [OSTI]

    Sayles, Todd Allen

    2008-01-01T23:59:59.000Z

    1.5 Superconductivity . . . . . . . . . . . . . . . . . . .and M. B. Maple, ”Superconductivity and non-Fermi liquidSAN DIEGO Magnetism and Superconductiviy in Pr-based Filled

  3. Magnetism and superconductivi[t]y in Pr-based filled skutterudite arsenides

    E-Print Network [OSTI]

    Sayles, Todd Allen

    2008-01-01T23:59:59.000Z

    1.3 Magnetism . . . . .1.3.3 Itinerant Magnetism . . . . . . . . . . .3.3 Magnetism . . . . . . . . . . . . . . . . . . . . . 3.4

  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. 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...

  18. 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

  19. 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 ...

  20. 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.

  1. 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:...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  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: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening aTurbulenceUtilize Available Resources Print AsVacancy-Induced

  16. 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,

  17. X-ray induced optical reflectivity

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

    Durbin, Stephen M.

    2012-01-01T23:59:59.000Z

    The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity.Optical absorption associated with band filling and band gap narrowing is shown to explain the basic features found in recent measurements on an insulator (silicon nitride, Si3N4), a semiconductor(gallium arsenide,GaAs), and a metal (gold,Au), obtained with ?100 fs x-ray pulses at 500-2000 eV and probed with 800 nm laser pulses. In particular GaAs exhibits an abrupt drop in reflectivity, persisting only for a time comparable to the x-ray excitation pulse duration, consistent with prompt band gap narrowing.

  18. 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).

  19. Ion Trap in a Semiconductor Chip

    E-Print Network [OSTI]

    D. Stick; W. K. Hensinger; S. Olmschenk; M. J. Madsen; K. Schwab; C. Monroe

    2006-01-09T23:59:59.000Z

    The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ion. Work on miniaturizing electromagnetic traps to the micrometer scale promises even higher levels of control and reliability. Compared with 'chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass spectrometer arrays, compact atomic clocks, and most notably, large scale quantum information processors. Here we report the operation of a micrometer-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool, and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium arsenide (GaAs) heterostructure.

  20. Micro-cooler enhancements by barrier interface analysis

    SciTech Connect (OSTI)

    Stephen, A.; Dunn, G. M. [Department of Physics, University of Aberdeen, King's College, AB24 3UE Aberdeen (United Kingdom)] [Department of Physics, University of Aberdeen, King's College, AB24 3UE Aberdeen (United Kingdom); Glover, J.; Oxley, C. H. [Department of Engineering, De Montfort University, Gateway, LE1 9BH Leicester (United Kingdom)] [Department of Engineering, De Montfort University, Gateway, LE1 9BH Leicester (United Kingdom); Bajo, M. Montes; Kuball, M. [Center for Device Thermography and Reliability, H. H. Wills Physics Laboratory, University of Bristol, BS8 1TL Bristol (United Kingdom)] [Center for Device Thermography and Reliability, H. H. Wills Physics Laboratory, University of Bristol, BS8 1TL Bristol (United Kingdom); Cumming, D. R. S.; Khalid, A. [School of Engineering, University of Glasgow, Rankine Building, G12 8LT Glasgow (United Kingdom)] [School of Engineering, University of Glasgow, Rankine Building, G12 8LT Glasgow (United Kingdom)

    2014-02-15T23:59:59.000Z

    A novel gallium arsenide (GaAs) based micro-cooler design, previously analysed both experimentally and by an analytical Heat Transfer (HT) model, has been simulated using a self-consistent Ensemble Monte Carlo (EMC) model for a more in depth analysis of the thermionic cooling in the device. The best fit to the experimental data was found and was used in conjunction with the HT model to estimate the cooler-contact resistance. The cooling results from EMC indicated that the cooling power of the device is highly dependent on the charge distribution across the leading interface. Alteration of this charge distribution via interface extensions on the nanometre scale has shown to produce significant changes in cooler performance.

  1. Research directions and progress in the SERI advanced high efficiency concept program

    SciTech Connect (OSTI)

    Cole, L.A.; Benner, J.P.

    1984-06-01T23:59:59.000Z

    The inherent electro-optical properties of gallium arsenide (GaAs) and related III-V compounds make this class of semiconductors an optimum choice for use in very high efficiency solar cells. The ability to alloy GaAs with other column III and V elements while maintaining the single crystal zincblende structure allows the photovoltaic properties to be tailored to specific needs. The current understanding and control of the properties of these materials is more advanced than for any other semiconductor except single crystal silicon. For these reasons, the Advanced High Efficiency Concepts Program supports materials research to improve the properties of III-V semiconductors needed to achieve the maximum attainable photovoltaic conversion efficiencies.

  2. Development of a 3-Dimensional Dosimetry System for Leksell Gamma Knife-Perfexion

    E-Print Network [OSTI]

    Yoon, KyoungJun; Lee, DoHeui; Cho, ByungChul; Lee, SangWook; Ahn, SeungDo

    2015-01-01T23:59:59.000Z

    The purpose of our study is to develop a new, 3-dimensional dosimetry system to verify the accuracy of dose deliveries in Leksell Gamma Knife-Perfexion TM (LGKP) (Elekta, Norcross, GA, USA). The instrument consists of a moving head phantom, an embedded thin active layer and a CCD camera system and was designed to be mounted to LGKP. As an active material concentrically located in the hemispheric head phantom, we choose Gafchromic EBT3 films and Gd2O2S;Tb phosphor sheets for dosimetric measurements. Also, to compensate the lack of backscatter, we located a 1 cm thick PMMA plate downstream of the active layer. The PMMA plate was transparent for scintillation lights to reach the CCD with 1200x1200 pixels by a 5.2 um pitch. Using this system, three hundred images by a 0.2 mm slice gap were acquired under each of three collimator setups, i.e. 4 mm, 8 mm, and 16 mm, respectively. The 2D projected images taken by CCD camera were compared with the dose distributions measured by EBT3 films in the same conditions. All ...

  3. (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

  4. (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

  5. (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

  6. (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

  7. (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

  8. (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

  9. (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

  10. (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

  11. (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

  12. 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.

  13. 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

  14. 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,

  15. 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.

  16. 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

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.

  1. 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.

  2. 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 ...

  3. 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.

  4. 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.

  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. 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.

  9. 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...

  10. 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.

  11. 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-

  12. 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...

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. P-T phase diagram of iron arsenide superconductor NdFeAsO0.88F0.12

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    the EPL website to read the latest articles published in cutting-edge fields of research from across of the referees to making all final acceptance decisions Impact Factor ­ The 2010 Impact Factor is 2.753; your Journal Citation Reports IMPACT FACTOR 500 000full text downloads in 2010 OVER 30 DAYS 16 961 average

  20. Production data on 0.55 eV InGaAs thermophotovoltaic cells

    SciTech Connect (OSTI)

    Wojtzuk, S.; Colter, P. [Spire Corp., Bedford, MA (United States); Charache, G.; Campbell, B. [Lockheed Martin, Inc., Schenectady, NY (United States)

    1996-05-01T23:59:59.000Z

    Low bandgap 0.55 eV (2.25 {micro}m cutoff wavelength) indium gallium arsenide (In{sub 0.72}Ga{sub 0.28}As) thermophotovoltaic (TPV) cells use much more of the long wavelength energy emitted from low temperature (< 1,200 C) thermal sources than either Si or GaSb cells. Data are presented on a statistically significant number (2,500) of these TPV cells, indicating the performance obtainable in large numbers of cells. This data should be useful in the design and modeling of TPV system performance. At 1.2 A/cm{sup 2} short-circuit current, an average open-circuit voltage of 283 mV is obtained with a 60% fill factor. The peak external quantum efficiency for uncoated cells is 65% and is over 50% from 1.1 to 2.2 {micro}m. Internal quantum efficiency is over 76% in this range assuming an estimated 34% reflectance loss.

  1. Updated Results of a Solid-State Sensor Irradiation Study for ILC Extreme Forward Calorimetry

    E-Print Network [OSTI]

    Courcoubetis, George; Fadeyev, Vitaliy; Kelley, Thomas; Martinez-McKinney, Forest; Schumm, Bruce A; Spencer, Edwin; Tang, Vivian; Wilder, Max

    2015-01-01T23:59:59.000Z

    Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower-max are expected to reach 100 MRad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e+e- `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiation damage to calorimeter sensors may be dominated by hadrons induced by nuclear interactions of shower photons, which are much more likely to contribute to the non-ionizing energy loss that has been observed to damage sensors exposed to hadronic radiation. We report here on the results of SLAC Experiment T-506, for which several different types of silicon diode and gallium-arsenide sensors were exposed to doses of radiati...

  2. 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.

  3. Thermal influence on charge carrier transport in solar cells based on GaAs PN junctions

    SciTech Connect (OSTI)

    Osses-Márquez, Juan; Calderón-Muñoz, Williams R., E-mail: wicalder@ing.uchile.cl [Department of Mechanical Engineering, University of Chile, Beauchef 850, Santiago (Chile)

    2014-10-21T23:59:59.000Z

    The electron and hole one-dimensional transport in a solar cell based on a Gallium Arsenide (GaAs) PN junction and its dependency with electron and lattice temperatures are studied here. Electrons and heat transport are treated on an equal footing, and a cell operating at high temperatures using concentrators is considered. The equations of a two-temperature hydrodynamic model are written in terms of asymptotic expansions for the dependent variables with the electron Reynolds number as a perturbation parameter. The dependency of the electron and hole densities through the junction with the temperature is analyzed solving the steady-state model at low Reynolds numbers. Lattice temperature distribution throughout the device is obtained considering the change of kinetic energy of electrons due to interactions with the lattice and heat absorbed from sunlight. In terms of performance, higher values of power output are obtained with low lattice temperature and hot energy carriers. This modeling contributes to improve the design of heat exchange devices and thermal management strategies in photovoltaic technologies.

  4. Ultra-low threshold, electrically pumped quantum dot photonic crystal nanocavity laser

    E-Print Network [OSTI]

    Bryan Ellis; Marie Mayer; Gary Shambat; Tomas Sarmiento; James Harris; Eugene Haller; Jelena Vuckovic

    2011-05-02T23:59:59.000Z

    Efficient, low threshold, and compact semiconductor laser sources are being investigated for many applications in high-speed communications, information processing, and optical interconnects. The best edge-emitting and vertical cavity surface-emitting lasers (VCSELs) have thresholds on the order of 100 \\muA[1,2] but dissipate too much power to be practical for many applications, particularly optical interconnects[3]. Optically pumped photonic crystal (PC) nanocavity lasers represent the state of the art in low-threshold lasers[4,5]; however, in order to be practical, techniques to electrically pump these structures must be developed. Here we demonstrate a quantum dot photonic crystal nanocavity laser in gallium arsenide pumped by a lateral p-i-n junction formed by ion implantation. Continuous wave lasing is observed at temperatures up to 150 K. Thresholds of only 181 nA at 50 K and 287 nA at 150 K are observed - the lowest thresholds ever observed in any type of electrically pumped laser.

  5. Ultrafast gating of proximity-focused microchannel-plate intensifiers

    SciTech Connect (OSTI)

    Lundy, A.S.; Iverson, A.E.

    1982-01-01T23:59:59.000Z

    Proximity-focused, microchannel-plate (MCP) image intensifiers have been used at Los Alamos for many years to allow single frame film and video exposure times in the range of 2.5 to 10 ns. There is now a program to reduce gating times to < 1 ns. This paper reviews previous work and the problems in achieving good resolution with gating times of < 1 ns. The key problems involve applying fast electrical gating signals to the tube elements. We present computer modeling studies of the combined tube, tube connection, and pulser system and show that low photocathode surface resistivity must be obtained to permit fast gating between the photocathode and the MCP input. We discuss ways of making low-resistivity S20 photocathodes, using gallium arsenide photocathodes, and various means of gating the tubes. A variety of pulser designs are being experimentally evaluated including spark gaps, avalanche transistors, Krytron tubes with sharpening gaps, step recovery diodes, and photoconductive elements (PCEs). The results of these studies are presented. Because of the high capacitances involved in most gating schemes, the tube connection geometry must be of low-impedance design, and our solution is presented. Finally, ways of testing these high-speed camera systems are discussed.

  6. 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).

  7. Estimates of occupational safety and health impacts resulting from large-scale production of major photovoltaic technologies

    SciTech Connect (OSTI)

    Owens, T.; Ungers, L.; Briggs, T.

    1980-08-01T23:59:59.000Z

    The purpose of this study is to estimate both quantitatively and qualitatively, the worker and societal risks attributable to four photovoltaic cell (solar cell) production processes. Quantitative risk values were determined by use of statistics from the California semiconductor industry. The qualitative risk assessment was performed using a variety of both governmental and private sources of data. The occupational health statistics derived from the semiconductor industry were used to predict injury and fatality levels associated with photovoltaic cell manufacturing. The use of these statistics to characterize the two silicon processes described herein is defensible from the standpoint that many of the same process steps and materials are used in both the semiconductor and photovoltaic industries. These health statistics are less applicable to the gallium arsenide and cadmium sulfide manufacturing processes, primarily because of differences in the materials utilized. Although such differences tend to discourage any absolute comparisons among the four photovoltaic cell production processes, certain relative comparisons are warranted. To facilitate a risk comparison of the four processes, the number and severity of process-related chemical hazards were assessed. This qualitative hazard assessment addresses both the relative toxicity and the exposure potential of substances in the workplace. In addition to the worker-related hazards, estimates of process-related emissions and wastes are also provided.

  8. Multilayer Ceramic Regenerator Materials for 4 K Cooling

    SciTech Connect (OSTI)

    Numazawa, T.; Kamiya, K. [Tsukuba Magnet Laboratory, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003 (Japan); Satoh, T. [Cryogenics Department, Sumitomo Heavy Industries, Ltd., 2-1-1 Yato-Cho, Nishitokyo City, Tokyo 188-8585 (Japan); Nozawa, H.; Yanagitani, T. [Ceramics Division, Konoshima Chemical Co. Ltd., 80 Koda, Takuma-Cho, Mitoyo-Gun, Kagawa 769-1103 (Japan)

    2006-04-27T23:59:59.000Z

    The ceramics oxide magnetic materials have shown excellent properties for use as regenerator materials used in 4 K crycoolers. Currently four kinds of oxide magnetic materials GdVO4, GAP=GdAlO3, GOS=Gd2O2S and Tb2O2S are available for applications for regenerators or thermal anchors from 2 K to 8 K. This paper focused on controlling the heat capacity of the (GdxTb1-x)2O2S system to cover the refrigeration temperatures between 6 K and 8 K. A concept of multilayer regenerator material consisting of multicomponent magnetic materials has been proposed and investigated. Two-layer ceramic material including two kinds of magnetic materials (Gd0.1Tb0.9)2O2S+Tb2O2S was successfully fabricated in the form of regenerator particles with an average diameter of 0.25 mm. Measured heat capacity data showed that it had twin peaks relating to those of (Gd0.1Tb0.9)2O2S and Tb2O2S, and the entire curve became broader and wider. The mechanical properties of strength and hardness of the two-layer ceramic material were the same as other ceramic regenerator materials like GOS. Thus, it is concluded that the multilayer ceramic material is very useful to control the heat capacity of the regenerator particles. The cooling tests using the two-layer ceramic material with HoCu2 and GOS have been done to investigate the 2nd stage regenerator configuration.

  9. 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...

  10. 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.

  11. 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...

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Investigation of Tunable Diode Spectroscopy for Monitoring Gases in Geothermal Plants

    SciTech Connect (OSTI)

    J. K. Partin

    2006-08-01T23:59:59.000Z

    The results of an investigation directed at the development of instrument-tation for the real-time monitoring of gases, such as hydrogen sulfide (H2S) and chloride (HCl), in geothermal process streams is described. The geothermal power industry has an interest in the development of new low maintenance techniques since improved capabilities could lead to considerable cost savings through the optimization of various gas abatement processes. Tunable diode laser spectroscopy was identified as a candidate tech-nology for this application and a commercial instrument was specified and procured for testing. The measurement principle involved the use of solid state diode lasers and frequency modulation techniques. The gallium arsenide diode lasers employed emit light in the 0.7 to 2.0 micron region of the electromagnetic spectrum. This region contains the overtone and combination absorption bands of a number of species of industrial interest, including H2S and HCl. A particular device can be tuned over a small range to match the absorption line by changing its applied temperature and current. The diode current can also be sinusoidally modulated in frequency as it is tuned across the line. This modulation allows measurements to be conducted at frequencies where the laser intensity noise is minimal; and therefore, very high signal-to-noise measurements are possible. The feasibility of using this technology in various types of geothermal process streams has been explored. The results of laboratory and field studies are presented along with new advances in laser technology that could allow more sensitive and selective measurements to be performed.

  18. Electrical and optical performance characteristics of 0.74eV p/n InGaAs monolithic interconnected modules

    SciTech Connect (OSTI)

    Wilt, D.M.; Weizer, V.G. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Fatemi, N.S.; Jenkins, P.P.; Hoffman, R.W. Jr. [Essential Research Inc., Cleveland, OH (United States); Jain, R.K. [National Research Council, Washington, DC (United States); Murray, C.S.; Riley, D.R. [Westinghouse Electric Corp., West Mifflin, PA (United States)

    1997-06-01T23:59:59.000Z

    There has been a traditional trade-off in thermophotovoltaic (TPV) energy conversion development between system efficiency and power density. This trade-off originates from the use of front surface spectral controls such as selective emitters and various types of filters. A monolithic interconnected module (MIM) structure has been developed which allows for both high power densities and high system efficiencies. The MIM device consists of many individual indium gallium arsenide (InGaAs) cells series-connected on a single semi-insulating indium phosphide (InP) substrate. The MIM is exposed to the entire emitter output, thereby maximizing output power density. An infrared (IR) reflector placed on the rear surface of the substrate returns the unused portion of the emitter output spectrum back to the emitter for recycling, thereby providing for high system efficiencies. Initial MIM development has focused on a 1 cm{sup 2} device consisting of eight series interconnected cells. MIM devices, produced from 0.74 eV InGaAs, have demonstrated V{sub oc} = 3.2 volts, J{sub sc} = 70 mA/cm{sup 2} and a fill factor of 66% under flashlamp testing. Infrared (IR) reflectance measurements (> 2 {micro}m) of these devices indicate a reflectivity of > 82%. MIM devices produced from 0.55 eV InGaAs have also been demonstrated. In addition, conventional p/n InGaAs devices with record efficiencies (11.7% AM0) have been demonstrated.

  19. The structure of GaAs/Si(211) heteroepitaxial layers

    SciTech Connect (OSTI)

    Liliental-Weber, Z.; Weber, E.R.; Washburn, J.; Liu, T.Y.; Kroemer, H.

    1985-05-01T23:59:59.000Z

    Gallium arsenide films grown on (211)Si by molecular-beam epitaxy have been investigated using transmission electron microscopy. The main defects observed in the alloy were of misfit dislocations, stacking faults, and microtwin lamellas. Silicon surface preparation was found to play an important role on the density of defects formed at the Si/GaAs interface. Two different types of strained-layer superlattices, InGaAs/InGaP and InGaAs/GaAs, were applied either directly to the Si substrate, to a graded layer (GaP-InGaP), or to a GaAs buffer layer to stop the defect propagation into the GaAs films. Applying InGaAs/GaAs instead of InGaAs/InGaP was found to be more effective in blocking defect propagation. In all cases of strained-layer superlattices investigated, dislocation propagation was stopped primarily at the top interface between the superlattice package and GaAs. Graded layers and unstrained AlGaAs/GaAs superlattices did not significantly block dislocations propagating from the interface with Si. Growing of a 50 nm GaAs buffer layer at 505/sup 0/C followed by 10 strained-layer superlattices of InGaAs/GaAs (5 nm each) resulted in the lowest dislocation density in the GaAs layer (approx.5 x 10/sup 7//cm/sup 2/) among the structures investigated. This value is comparable to the recently reported density of dislocations in the GaAs layers grown on (100)Si substrates. Applying three sets of the same strained layers decreased the density of dislocations an additional approx.2 to 3 times.

  20. 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 $\

  1. 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

  2. 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.

  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. 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

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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

  13. 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.

  14. 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

  15. 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 ...

  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. Oral Mucositis Prevention By Low-Level Laser Therapy in Head-and-Neck Cancer Patients Undergoing Concurrent Chemoradiotherapy: A Phase III Randomized Study

    SciTech Connect (OSTI)

    Gouvea de Lima, Aline [Departamento de Radiologia, Disciplina de Oncologia, Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Villar, Rosangela Correa [Instituto de Radiologia, Servico de Radioterapia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Castro, Gilberto de, E-mail: gilberto.castro@usp.br [Department of Clinical Oncology, Instituto do Cancer do Estado de Sao Paulo, Sao Paulo, SP (Brazil); Antequera, Reynaldo [Divisao de Odontologia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Gil, Erlon; Rosalmeida, Mauro Cabral [Instituto de Radiologia, Servico de Radioterapia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Federico, Miriam Hatsue Honda; Snitcovsky, Igor Moises Longo [Departamento de Radiologia, Disciplina de Oncologia, Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil)

    2012-01-01T23:59:59.000Z

    Purpose: Oral mucositis is a major complication of concurrent chemoradiotherapy (CRT) in head-and-neck cancer patients. Low-level laser (LLL) therapy is a promising preventive therapy. We aimed to evaluate the efficacy of LLL therapy to decrease severe oral mucositis and its effect on RT interruptions. Methods and Materials: In the present randomized, double-blind, Phase III study, patients received either gallium-aluminum-arsenide LLL therapy 2.5 J/cm{sup 2} or placebo laser, before each radiation fraction. Eligible patients had to have been diagnosed with squamous cell carcinoma or undifferentiated carcinoma of the oral cavity, pharynx, larynx, or metastases to the neck with an unknown primary site. They were treated with adjuvant or definitive CRT, consisting of conventional RT 60-70 Gy (range, 1.8-2.0 Gy/d, 5 times/wk) and concurrent cisplatin. The primary endpoints were the oral mucositis severity in Weeks 2, 4, and 6 and the number of RT interruptions because of mucositis. The secondary endpoints included patient-reported pain scores. To detect a decrease in the incidence of Grade 3 or 4 oral mucositis from 80% to 50%, we planned to enroll 74 patients. Results: A total of 75 patients were included, and 37 patients received preventive LLL therapy. The mean delivered radiation dose was greater in the patients treated with LLL (69.4 vs. 67.9 Gy, p = .03). During CRT, the number of patients diagnosed with Grade 3 or 4 oral mucositis treated with LLL vs. placebo was 4 vs. 5 (Week 2, p = 1.0), 4 vs. 12 (Week 4, p = .08), and 8 vs. 9 (Week 6, p = 1.0), respectively. More of the patients treated with placebo had RT interruptions because of mucositis (6 vs. 0, p = .02). No difference was detected between the treatment arms in the incidence of severe pain. Conclusions: LLL therapy was not effective in reducing severe oral mucositis, although a marginal benefit could not be excluded. It reduced RT interruptions in these head-and-neck cancer patients, which might translate into improved CRT efficacy.

  18. 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

  19. Complex States, Emergent Phenomena & Superconductivity in Intermetalli...

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

    could be made without rare earths. Crossing Over from "Normal" to "Superconducting" A new ultra-fast laser technique has yielded insights into how iron arsenide materials evolve to...

  20. New ternary phosphides and arsenides. Syntheses, crystal structures, physical properties of Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}

    SciTech Connect (OSTI)

    Wang, Jian [State Key Laboratory of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan, Shandong 250100 (China); Xia, Sheng-Qing, E-mail: shqxia@sdu.edu.cn [State Key Laboratory of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan, Shandong 250100 (China); Tao, Xu-Tang [State Key Laboratory of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan, Shandong 250100 (China); Schäfer, Marion C. [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Bobev, Svilen, E-mail: bobev@udel.edu [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States)

    2013-09-15T23:59:59.000Z

    Three new europium pnictides Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3} have been synthesized and their structures were determined by single-crystal X-ray diffraction. Eu{sub 2}ZnP{sub 2} is isotypic with Yb{sub 2}CdSb{sub 2} (Cmc2{sub 1} (No. 36); cell parameters a=4.1777(7) Å, b=15.925(3) Å, c=7.3008(12) Å), while the latter two compounds crystallize with the Ba{sub 2}Cd{sub 2}Sb{sub 3} structure type (C2/m (No. 12); cell parameters a=15.653(5)/16.402(1) Å, b=4.127(1)/4.445(4) Å, c=11.552(4)/12.311(1) Å and ?=126.647(4)/126.515(7)° for Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}, respectively). Magnetic susceptibility measurements in the interval 5–300 K confirm paramagnetic behavior and effective magnetic moments characteristic of Eu{sup 2+} ([Xe] 4f{sup 7}) ground states. Temperature-dependent electrical conductivity measurements also prove that Eu{sub 2}Cd{sub 2}As{sub 3} is a semiconducting compound with a narrow band gap of 0.059 eV below 100 K. According to TG/DSC analyses, Eu{sub 2}Cd{sub 2}As{sub 3} starts to decompose at about 950 K. - Graphical abstract: A polyhedral view of the crystal structure of new pnictides Eu{sub 2}T{sub 2}Pn{sub 3} (T=Zn or Cd; Pn=P or As). Display Omitted - Highlights: • Three new ternary pnictide Zintl compounds, Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}, have been synthesized and characterized. • The europium cations are divalent and ferromagnetically coupled in both Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}. • Eu{sub 2}Cd{sub 2}As{sub 3} has a very small band gap of 0.06 eV and starts to decompose over 950 K.

  1. 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...

  2. 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.

  3. 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:...

  4. 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

  5. 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...

  6. 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

  7. 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

  8. 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

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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).

  16. Clean process to destroy arsenic-containing organic compounds with recovery of arsenic

    DOE Patents [OSTI]

    Upadhye, R.S.; Wang, F.T.

    1996-08-13T23:59:59.000Z

    A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic. 1 fig.

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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

  2. IEEE ELECTRON DEVICE LETTERS, VOL. 12, NO. 12. DECEMBER 1991 An InAlAs/InAs MODFET

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    -behaved characteristics, showing sharp pinch-off ( V,, = -0.8 V) and small output con- ductance (5 mS/mm) at 300 K's that only contain arsenides because of their well-established growth and pro- cessing technologies of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139. IEEE

  3. Simple intrinsic defects in InAs : numerical predictions.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2013-03-01T23:59:59.000Z

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  4. 0361-0128/12/4012/275-20 275 Introduction

    E-Print Network [OSTI]

    -rich melts at temperatures lower than 1,000°C. Hence, arsenides and sulfarsenides may play a role, mineralogy, in situ mineral chemistry (by LA-ICP- MS[laser ablation-inductively coupled plasma-mass spec) in selected samples represen

  5. Nematic spin fluid in the tetragonal phase of BaFe2As2 Leland W. Harriger 1

    E-Print Network [OSTI]

    Hu, Jiangping

    of Sciences, Beijing 100190, China 3 ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot as the source of the pseudogap behavior observed in copper oxide superconductors17-19 . Furthermore of the lattice and magnetic transitions in iron arsenides, but will also determine the importance of electron

  6. Resonant Spin Excitation in the High Temperature Superconductor Ba0.6K0.4Fe2As2

    SciTech Connect (OSTI)

    Christianson, Andrew D [ORNL; Goremychkin, E. A. [ISIS Facility, Rutherford Appleton Laboratory; Osborn, R. [Argonne National Laboratory (ANL); Rosenkranz, Stephen [Argonne National Laboratory (ANL); Lumsden, Mark D [ORNL; Malliakas, C. [Northwestern University, Evanston; Todorov, L. [Northwestern University, Evanston; Claus, H. [Northwestern University, Evanston; Chung, D.Y. [Northwestern University, Evanston; Kanatzidis, M. [Northwestern University, Evanston; Bewley, Robert I. [ISIS Facility, Rutherford Appleton Laboratory; Guidi, T. [ISIS Facility, Rutherford Appleton Laboratory

    2008-01-01T23:59:59.000Z

    A new family of superconductors containing layers of iron arsenide has attracted considerable interest because of their high transition temperatures (T{sub c}), some of which are >50 K, and because of similarities with the high-{sub c} copper oxide superconductors. In both the iron arsenides and the copper oxides, superconductivity arises when an antiferromagnetically ordered phase has been suppressed by chemical doping. A universal feature of the copper oxide superconductors is the existence of a resonant magnetic excitation, localized in both energy and wavevector, within the superconducting phase. This resonance, which has also been observed in several heavy-fermion superconductors is predicted to occur when the sign of the superconducting energy gap takes opposite values on different parts of the Fermi surface, an unusual gap symmetry which implies that the electron pairing interaction is repulsive at short range. Angle-resolved photoelectron spectroscopy shows no evidence of gap anisotropy in the iron arsenides, but such measurements are insensitive to the phase of the gap on separate parts of the Fermi surface. Here we report inelastic neutron scattering observations of a magnetic resonance below T{sub c} in Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2}, a phase-sensitive measurement demonstrating that the superconducting energy gap has unconventional symmetry in the iron arsenide superconductors.

  7. Transition from Three-Dimensional Anisotropic Spin Excitations to Two-Dimensional Spin Excitations by Electron Doping the FeAs-Based BaFe1:96Ni0:04As2 Superconductor

    E-Print Network [OSTI]

    Hu, Jiangping

    by Electron Doping the FeAs-Based BaFe1:96Ni0:04As2 Superconductor Leland W. Harriger,1 Astrid Schneidewind,2 arsenides is important because high-transition temperature (high-Tc) superconductivity arises from electron optimal superconductivity [4­6], the gapped spin wave excitations were replaced by a gapless continuum

  8. The relevance of contemporary bronze casting in Ubon, Thailand for understanding the archaeological record of the Bronze Age in Peninsular Southeast Asia

    E-Print Network [OSTI]

    Everly, Daniel Eugene

    2006-04-12T23:59:59.000Z

    ????????????........ 109 Bowl Furnace Construction????????????.. 109 Melting the Bronze?????????????........... 110 Pouring the Molten Bronze??????????........... 111 Removing the Bronze Product from the Clay Mould........... 112... arsenides) following the addition of the arsenic material to the molten copper with its subsequent diffusion into the copper due to the miscibility (blending) qualities of the two materials. ?Once the arsenates were exhausted in copper deposits...

  9. 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 ...

  10. 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

  11. 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.

  12. 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 ...

  13. 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 ...

  14. 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 ...

  15. 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

  16. 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

  17. 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

  18. 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...

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Wrapping process for fabrication of A-15 superconducting composite wires

    DOE Patents [OSTI]

    Suenaga, M.; Klamut, C.J.; Luhman, T.S.

    1980-08-15T23:59:59.000Z

    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.

  5. Fuel Cell Systems Air Management

    E-Print Network [OSTI]

    Air Management Honeywell TIAX UTC Mechanology, LLC · Turbocompressor for PEM Fuel Cells · Hybrid-Machined Thin Film H2 Gas Sensors - ATMI · Sensor Development for PEM Fuel Cell Systems ­ Honeywell · Gallium

  6. Sandia National Laboratories: SAND 2013-0469 P

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

    Efficiency, Solid-State Lighting A new top-down method for fabricating gallium nitride (GaN) nanowires with precisely controlled geometries enables single-mode, rather than...

  7. 2DEG electrodes for piezoelectric transduction of AlGaN/GaN MEMS resonators

    E-Print Network [OSTI]

    Weinstein, Dana

    A 2D electron gas (2DEG) interdigitated transducer (IDT) in Gallium Nitride (GaN) resonators is introduced and demonstrated. This metal-free transduction does not suffer from the loss mechanisms associated with more commonly ...

  8. Amorphization Processes in Au Ion Irradiated GaN at 150 - 300...

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

    Processes in Au Ion Irradiated GaN at 150 - 300 K. Amorphization Processes in Au Ion Irradiated GaN at 150 - 300 K. Abstract: Epitaxial single-crystal gallium nitride (GaN) films...

  9. Sandia National Laboratories: BES EFRC

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

    Efficiency, Solid-State Lighting A new top-down method for fabricating gallium nitride (GaN) nanowires with precisely controlled geometries enables single-mode, rather than...

  10. Soraa Is Optimizing the Use of Non-Polar and Semi-Polar Substrates...

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

    effects on cost as well as performance. Non-polar and semi-polar gallium nitride (GaN), combined with low defect density freestanding bulk-GaN technology, offers significant...

  11. Epitaxial Thin Film XRD | EMSL

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

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

  12. Sandia National Laboratories: solid-state lighting science

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

    Efficiency, Solid-State Lighting A new top-down method for fabricating gallium nitride (GaN) nanowires with precisely controlled geometries enables single-mode, rather than...

  13. Sandia National Laboratories: GaN-based nanowire laser

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

    GaN-based nanowire laser BES Web Highlight: Single-mode gallium nitride nanowire lasers On January 28, 2013, in EC, Energy Efficiency, Solid-State Lighting A new top-down method...

  14. Sandia National Laboratories: Light Creation Materials

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

    for example ZnO, will be important. AlGaInN Materials LEDs based on gallium nitride (GaN) and ternary ... Last Updated: June 13, 2012 Go To Top Exceptional service in the...

  15. Veeco

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

    to design indium gallium nitride (InGaN) MOCVD growth systems. The actual experimental GaN non-uniformity is about four times greater than predicted because the model does not...

  16. 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.

  17. OBSERVATOIRE DE GRENOBLE LABORATOIRE DE GEOPHYSIQUE INTERNE ET TECTONOPHYSIQUE

    E-Print Network [OSTI]

    Boyer, Edmond

    source d'´energie la plus probable de la g´eodynamo, qui entretient le champ magn´etique de la plan´elisation de l'´ecou- lement convectif sans champ d'un m´etal liquide (le gallium), `a grand for¸cage thermique, and aims at modelling the non-magnetic convective flow of a spherical shell of liquid metal (gallium

  18. Carrier transfer from InAs quantum dots to ErAs metal nanoparticles

    SciTech Connect (OSTI)

    Haughn, C. R.; Chen, E. Y.; Zide, J. M. O.; Doty, M. F., E-mail: doty@udel.edu [Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716 (United States); Steenbergen, E. H.; Bissell, L. J.; Eyink, K. G. [AFRL/RXAN, Wright Patterson AFB, Ohio 45433 (United States)

    2014-09-08T23:59:59.000Z

    Erbium arsenide (ErAs) is a semi-metallic material that self-assembles into nanoparticles when grown in GaAs via molecular beam epitaxy. We use steady-state and time-resolved photoluminescence to examine the mechanism of carrier transfer between indium arsenide (InAs) quantum dots and ErAs nanoparticles in a GaAs host. We probe the electronic structure of the ErAs metal nanoparticles (MNPs) and the optoelectronic properties of the nanocomposite and show that the carrier transfer rates are independent of pump intensity. This result suggests that the ErAs MNPs have a continuous density of states and effectively act as traps. The absence of a temperature dependence tells us that carrier transfer from the InAs quantum dots to ErAs MNPs is not phonon assisted. We show that the measured photoluminescence decay rates are consistent with a carrier tunneling model.

  19. Thermionic-photovoltaic energy converter

    SciTech Connect (OSTI)

    Chubb, D. L.

    1985-07-09T23:59:59.000Z

    A thermionic-photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or galium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

  20. Low temperature transport in p-doped InAs nanowires

    SciTech Connect (OSTI)

    Upadhyay, S.; Jespersen, T. S.; Madsen, M. H.; Krogstrup, P.; Nygård, J. [Center for Quantum Devices and Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)] [Center for Quantum Devices and Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)

    2013-10-14T23:59:59.000Z

    We present low temperature electrical measurements of p-type Indium Arsenide nanowires grown via molecular beam epitaxy using Beryllium as a dopant. Growth of p-type wires without stacking faults is demonstrated. Devices in field-effect geometries exhibit ambipolar behavior, and the temperature dependence of electron and hole field effect mobilities are extracted. At low temperatures, we observe reproducible conductance fluctuations as a result of quantum interference, and magnetoconductance data show weak antilocalization.

  1. Synthesis and characterization of actinide metal compounds formed by combustion

    SciTech Connect (OSTI)

    Behrens, R.G.; King, M.A.

    1985-01-01T23:59:59.000Z

    This paper briefly describes the results of attempts to synthesize arsenides, phosphides, and antimonides of uranium and thorium using Self-Propagating High-Temperature Synthesis (SHS) techniques. This paper first summarizes the chemistry and thermodynamics of these chemical systems, describes SHS synthesis techniques, and then describes the results of the syntheses using data from powder x-ray diffraction, metallographic, and electron microprobe analyses.

  2. Sulfide-Driven Arsenic Mobilization from Arsenopyrite and Black Shale Pyrite

    SciTech Connect (OSTI)

    Zhu, W.; Young, L; Yee, N; Serfes, M; Rhine, E; Reinfelder, J

    2008-01-01T23:59:59.000Z

    We examined the hypothesis that sulfide drives arsenic mobilization from pyritic black shale by a sulfide-arsenide exchange and oxidation reaction in which sulfide replaces arsenic in arsenopyrite forming pyrite, and arsenide (As-1) is concurrently oxidized to soluble arsenite (As+3). This hypothesis was tested in a series of sulfide-arsenide exchange experiments with arsenopyrite (FeAsS), homogenized black shale from the Newark Basin (Lockatong formation), and pyrite isolated from Newark Basin black shale incubated under oxic (21% O2), hypoxic (2% O2, 98% N2), and anoxic (5% H2, 95% N2) conditions. The oxidation state of arsenic in Newark Basin black shale pyrite was determined using X-ray absorption-near edge structure spectroscopy (XANES). Incubation results show that sulfide (1 mM initial concentration) increases arsenic mobilization to the dissolved phase from all three solids under oxic and hypoxic, but not anoxic conditions. Indeed under oxic and hypoxic conditions, the presence of sulfide resulted in the mobilization in 48 h of 13-16 times more arsenic from arsenopyrite and 6-11 times more arsenic from isolated black shale pyrite than in sulfide-free controls. XANES results show that arsenic in Newark Basin black shale pyrite has the same oxidation state as that in FeAsS (-1) and thus extend the sulfide-arsenide exchange mechanism of arsenic mobilization to sedimentary rock, black shale pyrite. Biologically active incubations of whole black shale and its resident microorganisms under sulfate reducing conditions resulted in sevenfold higher mobilization of soluble arsenic than sterile controls. Taken together, our results indicate that sulfide-driven arsenic mobilization would be most important under conditions of redox disequilibrium, such as when sulfate-reducing bacteria release sulfide into oxic groundwater, and that microbial sulfide production is expected to enhance arsenic mobilization in sedimentary rock aquifers with major pyrite-bearing, black shale formations.

  3. Final Technical Report of project: "Contactless Real-Time Monitoring of Paper Mechanical Behavior During Papermaking"

    SciTech Connect (OSTI)

    Emmanuel Lafond; Paul Ridgway; Ted Jackson; Rick Russo; Ken Telschow; Vance Deason; Yves Berthelot; David Griggs; Xinya Zhang; Gary Baum

    2005-08-30T23:59:59.000Z

    The early precursors of laser ultrasonics on paper were Prof. Y. Berthelot from the Georgia Institute of Technology/Mechanical Engineering department, and Prof. P. Brodeur from the Institute of Paper Science and Technology, both located in Atlanta, Georgia. The first Ph.D. thesis that shed quite some light on the topic, but also left some questions unanswered, was completed by Mont A. Johnson in 1996. Mont Johnson was Prof. Berthelot's student at Georgia Tech. In 1997 P. Brodeur proposed a project involving himself, Y. Berthelot, Dr. Ken Telschow and Mr. Vance Deason from INL, Honeywell-Measurex and Dr. Rick Russo from LBNL. The first time the proposal was not accepted and P. Brodeur decided to re-propose it without the involvement from LBNL. Rick Russo proposed a separate project on the same topic on his side. Both proposals were finally accepted and work started in the fall of 1997 on the two projects. Early on, the biggest challenge was to find an optical detection method which could detect laser-induced displacements of the web surface that are of the order of .1 micron in the ultrasonic range. This was to be done while the web was having an out-of-plane amplitude of motion in the mm range due to web flutter; while moving at 10 m/s to 30 m/s in the plane of the web, on the paper machine. Both teams grappled with the same problems and tried similar methods in some cases, but came up with two similar but different solutions one year later. The IPST, GT, INL team found that an interferometer made by Lasson Technologies Inc. using the photo-induced electro-motive force in Gallium Arsenide was able to detect ultrasonic waves up to 12-15 m/s. It also developed in house an interferometer using the Two-Wave Mixing effect in photorefractive crystals that showed good promises for on-line applications, and experimented with a scanning mirror to reduce motion-induced texture noise from the web and improve signal to noise ratio. On its side, LBNL had the idea to combine a commercial Mach-Zehnder interferometer to a spinning mirror synchronized to the web speed, in order to make almost stationary measurements. The method was demonstrated at up to 10 m/s. Both teams developed their own version of a web simulator that was driving a web of paper at 10 m/s or higher. The Department of Energy and members of the Agenda 2020 started to make a push for merging the two projects. This made sense because their topics were really identical but this was not well received by Prof. Brodeur. Finally IPST decided to reassign the direction of the IPST-INL-GT project in the spring of 1999 to Prof. Chuck Habeger so that the two teams could work together. Also at this time, Honeywell-Measurex dropped as a member of the team. It was replaced by ABB Industrial Systems whose engineers had extensive previous experience of working with ultrasonic sensors on paperboard. INL also finished its work on the project as its competencies were partly redundant with LBNL. From the summer of 1999, the IPST-GT and LBNL teams were working together and helped each other often by collaborating and visiting either laboratory when was necessary. Around the beginning of 2000, began an effort at IPST to create an off-line laser-ultrasonics instrument that could perform automated measurements of paper and paperboard's bending stiffness. It was widely known that the mechanical bending tests of paper used for years by the paper industry were very inaccurate and exhibited poor reproducibility; therefore the team needed a new instrument of reference to validate its future on-line results. In 1999-2000, the focus of the on-line instrument was on a pre-industrial demonstration on a pilot coater while reducing the damage to the web caused by the generation laser, below the threshold where it could be visible by the naked eye. During the spring of 2000 Paul Ridgway traveled to IPST and brought with him a redesigned system still using the same Mach-Zehnder interferometer as before, but this time employing an electric motor-driven spinning mirror instead of the previously belt-driven m

  4. Group III-nitride thin films grown using MBE and bismuth

    DOE Patents [OSTI]

    Kisielowski, Christian K. (Peidmont, CA); Rubin, Michael (Berkeley, CA)

    2000-01-01T23:59:59.000Z

    The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

  5. Group III-nitride thin films grown using MBE and bismuth

    DOE Patents [OSTI]

    Kisielowski, Christian K. (Piedmont, CA); Rubin, Michael (Berkeley, CA)

    2002-01-01T23:59:59.000Z

    The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

  6. High efficiency radioisotope thermophotovoltaic prototype generator

    SciTech Connect (OSTI)

    Avery, J.E.; Samaras, J.E.; Fraas, L.M.; Ewell, R. [JX Crystals, Inc., Issaquah, WA (United States)

    1995-10-01T23:59:59.000Z

    A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, the authors present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. They compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. They find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. The authors propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter.

  7. Cyclotron Radiopharmaceuticals Production at the V.G. Khlopin Radium Institute

    SciTech Connect (OSTI)

    Solin, L.M.; Kudelin, B.K.; Jakovlev, V.A.; Potapova, T.S.; Gromova, E.A. [V.G.Khlopin Radium Institute, 2nd Murinsky pr., 28, 194021 St. Petersburg (Russian Federation)

    2003-08-26T23:59:59.000Z

    For more than 10 years Radium Institute is producing radiopharmaceuticals for St. Petersburg (Russia) hospitals. We have developed technologies for sodium iodide, sodium iodohippurate, MIBG and BMIPP, labeled by iodine-123, and gallium-67 citrate. Radionuclidic purity of 99,98% is reached for radiopharmaceuticals labeled by iodine-123. Radionuclidic purity is over 99.9% for gallium-67 citrate on the date of delivery. Radiochemical purity of 95% and more is reached through the application of appropriate technologies for each RPH. It takes no longer than 4 hours for all technologies. Over 150,000 patients were investigated.

  8. Ferromagnetism in undoped One-dimensional GaN Nanowires

    SciTech Connect (OSTI)

    Jeganathan, K., E-mail: kjeganathan@yahoo.com, E-mail: jagan@physics.bdu.ac.in; Purushothaman, V. [Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli - 620 024 (India)] [Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli - 620 024 (India); Debnath, R. [Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario M5S 3G4 (Canada)] [Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario M5S 3G4 (Canada); Arumugam, S. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli – 620 024 (India)] [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli – 620 024 (India)

    2014-05-15T23:59:59.000Z

    We report an intrinsic ferromagnetism in vertical aligned GaN nanowires (NW) fabricated by molecular beam epitaxy without any external catalyst. The magnetization saturates at ?0.75 × emu/gm with the applied field of 3000 Oe for the NWs grown under the low-Gallium flux of 2.4 × 10{sup ?8} mbar. Despite a drop in saturation magnetization, narrow hysteresis loop remains intact regardless of Gallium flux. Magnetization in vertical standing GaN NWs is consistent with the spectral analysis of low-temperature photoluminescence pertaining to Ga-vacancies associated structural defects at the nanoscale.

  9. Site control technique for quantum dots using electron beam induced deposition

    SciTech Connect (OSTI)

    Iizuka, Kanji; Jung, JaeHun; Yokota, Hiroshi [Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro, Minami-saitama, Saitama 3458501 (Japan)

    2014-05-15T23:59:59.000Z

    To develop simple and high throughput sit definition technique for quantum dots (QDs), the electron beam induced deposition (EBID) method was used as desorption guide of phosphorus atoms form InP substrate. As the results one or a few indium (In) droplets (DLs) were created in the carbon grid pattern by thermal annealing at a temperature of 450°C for 10 min in the ultra high vacuum condition. The size of In DLs was larger than QDs, but arsenide DLs by molecular beam in growth chamber emitted wavelength of 1.028?m at 50K by photoluminescence measurement.

  10. 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

  11. Transphorm Takes Energy Efficiency to a New Level

    Broader source: Energy.gov [DOE]

    Transphorm, a startup partially funded by ARPA-E, develops Gallium nitride (GaN) semiconductors that could be used to make cost-effective, high-performance power converters for electric motor drives and components of solar panels and electric vehicles.

  12. CX-011468: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Advanced Low-Cost Silicon-Carbide (SiC) and Gallium-Nitride (GaN) Wide Bandgap Inverters for Under-the-Hood Electric Vehicle Traction... CX(s) Applied: B3.6 Date: 10/29/2013 Location(s): Michigan Offices(s): National Energy Technology Laboratory

  13. PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS Prog. Photovolt: Res. Appl. 2006; 14:2543

    E-Print Network [OSTI]

    Anderson, Timothy J.

    PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS Prog. Photovolt: Res. Appl. 2006; 14 Solar Energy, Inc., 5575 S. Houghton Rd, Tucson, AZ 85747, USA 7 Energy Photovoltaics, Inc., 276 Bakers transport within copper indium gallium sulfoselenide (CIGSS) photovoltaic devices, whose absorber layers

  14. EUROPHYSICS Published under the scientific responsibility of the

    E-Print Network [OSTI]

    Zheludev, Nikolay

    Incorporating JOURNAL DE PHYSIQUE LETTRES · LETTERE AL NUOVO CIMENTO OFFPRINT Vol. 67 · Number 4 · pp. 614­619 Controlling the coexistence of structural phases and the optical properties of gallium nanoparticles Production Editor: Paola Marangon Publishers: EDP Sciences S.A., France - Società Italiana di Fisica, Italy

  15. United States Patent: 7309798 http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOF... 1 of 9 12/31/2007 8:42 AM

    E-Print Network [OSTI]

    Iglesia, Enrique

    Process for carbonylation of alkyl ethers Abstract A product comprising a lower alkyl ester of a lower an additional framework metal such as gallium, boron and/or iron, under substantially anhydrous conditions. More 11123581 May., 2005 Current U.S. Class: 560/232 Current International Class: C07C 67/36 (20060101

  16. Energy Procedia 15 (2012) 67 77 1876-6102 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the organizing committee of International Conference

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    Energy Procedia 15 (2012) 67 ­ 77 1876-6102 © 2011 Published by Elsevier Ltd. Selection and/or peer is given to tri-doping, a technique consisting on the addition of gallium to boron and phosphorus doped UMG ramping up of production capacity, thanks to the use of relatively simple equipment and techniques

  17. Minerals Use in Safety Applications in the Workplace Many of the applications described below are found in and around the U.S. Geological Survey

    E-Print Network [OSTI]

    Torgersen, Christian

    communications equipment, including computers and cell phones, as well as in gallium-based solar cells that power that provide power to emergency lighting fixtures and backup power to medical equipment. #12;2 Cement. Copper--Copper wiring provides power for emergency lighting systems and power and signal transmission

  18. Delta II rocket launching the Mars Exploration Rover,

    E-Print Network [OSTI]

    Torgersen, Christian

    , global positioning systems, and defense and aerospace applications. Printed on recycled paper Ga [Ar]4s2-temperature thermometers and in designing metal alloys that melt easily. The development of a gallium-based direct band for the aerospace and telecommunications industries. They are also used in the production of highly specialized

  19. Energy Research and Development Division FINAL PROJECT REPORT

    E-Print Network [OSTI]

    FOR GALLIUM NITRIDE LIGHT EMITTING DIODE DEVICES DECEMBER 2012 CEC5002013027 Prepared for: California Nitride Light Emitting Diode Devices is the final report for the grant, PIR10055, conducted by Applied the Energy Commission at 9163271551. #12;3 ABSTRACT For light emitting diodes (LEDs) to realiz

  20. Reaction of Aluminum with Water to Produce Hydrogen

    E-Print Network [OSTI]

    Aluminum Alloys PROPERTIES OF THE ALUMINUM-WATER REACTIONS RELATIVE ........... 14 TO ON-BOARD SYSTEM aluminum alloys such as aluminum-lithium and aluminum-gallium has been studied. In this case, the molten nature of the alloy prevents the development of a coherent and adherent aluminum oxide layer. However

  1. Aluminum battery alloys

    DOE Patents [OSTI]

    Thompson, David S. (Richmond, VA); Scott, Darwin H. (Mechanicsville, VA)

    1985-01-01T23:59:59.000Z

    Aluminum alloys suitable for use as anode structures in electrochemical cs are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  2. Sandia Energy - Light Creation Materials

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

    ZnO, will be important. AlGaInN Materials LEDs based on gallium nitride (GaN) and ternary alloys with indium (InGaN) and aluminum (AlGaN) as well as quaternary alloys (AlGaInN) can...

  3. Reaction of Aluminum with Water to Produce Hydrogen

    E-Print Network [OSTI]

    Aluminum Alloys PROPERTIES OF THE ALUMINUM-WATER REACTIONS RELATIVE ........... 14 TO ON-BOARD SYSTEM metal. In addition, the reaction of water with molten aluminum alloys such as aluminum-lithium and aluminum-gallium has been studied. In this case, the molten nature of the alloy prevents the development

  4. Aluminum battery alloys

    DOE Patents [OSTI]

    Thompson, D.S.; Scott, D.H.

    1984-09-28T23:59:59.000Z

    Aluminum alloys suitable for use as anode structures in electrochemical cells are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  5. J. Fluid Mech. (2004), vol. 515, pp. 391413. c 2004 Cambridge University Press DOI: 10.1017/S0022112004000527 Printed in the United Kingdom

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2004-01-01T23:59:59.000Z

    heat and mass transfer problem of significance in both fundamental fluid mechanics and engineering investigations of the onset of oscillatory convection in a sidewall heated rectangular cavity of molten gallium simulations of a three-dimensional Boussinesq model. The onset of time-dependence takes place through

  6. CX-001137: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Advanced Epi Tools for Gallium Nitride LED (Light Emitting Diode) DevicesCX(s) Applied: B3.6Date: 03/05/2010Location(s): Santa Clara, CaliforniaOffice(s): Energy Efficiency and Renewable Energy, National Energy Technology Laboratory

  7. Formation of manganese -doped atomic layer in wurtzite GaN Meng Shi, Abhijit Chinchore, Kangkang Wang, Andrada-Oana Mandru, Yinghao Liu et al.

    E-Print Network [OSTI]

    Formation of manganese -doped atomic layer in wurtzite GaN Meng Shi, Abhijit Chinchore, Kangkang in wurtzite GaN Meng Shi, Abhijit Chinchore, Kangkang Wang, Andrada-Oana Mandru, Yinghao Liu, and Arthur R 2012) We describe the formation of a d-doped manganese layer embedded within c-plane wurtzite gallium

  8. Design Constraints for Liquid-Protected Divertors S. Shin, S. I. Abdel-Khalik

    E-Print Network [OSTI]

    California at San Diego, University of

    , and particle surface interactions to establish the operating windows for candidate liquids [4]. Lithium, Flibe for lithium, Flibe, lithium- lead, tin, and gallium are presented. The generalized charts developed. INTRODUCTION Work on liquid-surface-protected plasma facing components, and plasma surface interactions, has

  9. CONF-881031--66 DE89 007397

    E-Print Network [OSTI]

    Harilal, S. S.

    liquid-metals are evaluated, i.e., lithium, gallium, andtin. A wide range of reactor operating conditions-1O9-Eng-38. cope up with a large heat loads it must also withstand severe surface erosion during both normal and off-normal operating conditions. Under most conditions the major mechanism of erosion during

  10. Method for non-invasive detection of ocular melanoma

    DOE Patents [OSTI]

    Lambrecht, Richard M. (Quogue, NY); Packer, Samuel (Floral Park, NY)

    1984-01-01T23:59:59.000Z

    There is described an apparatus and method for diagnosing ocular cancer that is both non-invasive and accurate which comprises two radiation detectors positioned before each of the patient's eyes which will measure the radiation level produced in each eye after the administration of a tumor-localizing radiopharmaceutical such as gallium-67.

  11. Differential radioactivity monitor for non-invasive detection of ocular melanoma

    DOE Patents [OSTI]

    Lambrecht, R.M.; Packer, S.

    1982-09-23T23:59:59.000Z

    There is described an apparatus and method for diagnosing ocular cancer that is both non-invasive and accurate which comprises two radiation detectors positioned before each of the patient's eyes which will measure the radiation level produced in each eye after the administration of a tumor-localizing radiopharmaceutical such as gallium-67.

  12. Method for non-invasive detection of ocular melanoma

    DOE Patents [OSTI]

    Lambrecht, R.M.; Packer, S.

    1984-10-30T23:59:59.000Z

    An apparatus and method is disclosed for diagnosing ocular cancer that is both non-invasive and accurate. The apparatus comprises two radiation detectors positioned before each of the patient's eyes which will measure the radiation level produced in each eye after the administration of a tumor-localizing radiopharmaceutical such as gallium-67. 2 figs.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. Development of Co-Ni-Ga Ferromagnetic Shape Memory Alloys (FSMAs) by Investigating the Effects of Solidification Processing Parameters

    E-Print Network [OSTI]

    Kalaantari, Haamun

    2013-01-01T23:59:59.000Z

    T. Nishizawa, K. Ishida, Co-Ni (Cobalt-Nickel). In: BinaryOhio, 1990, pp. [92] H. Okamoto, Co-Ga (Cobalt-Gallium). In:23 Fig. 14. DSC curve of Co-23.5at%Ni-30at%Ga (a) and

  1. 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.

  2. A compact physical model for morphology induced intrinsic degradation of organic bulk heterojunction solar cell

    E-Print Network [OSTI]

    Alam, Muhammad A.

    for an intrinsic degradation concern for bulk heterojunction type organic photovoltaic (BH-OPV) cells that involveA compact physical model for morphology induced intrinsic degradation of organic bulk-induced degradation in Si-based cell (Staebler-Wronski effect), Cu diffusion in thin film (copper indium gallium

  3. Highly Responsive Ultrathin GaS Nanosheet Photodetectors on Rigid and Flexible Substrates

    E-Print Network [OSTI]

    Geohegan, David B.

    -zone horizontal furnace with a fused silica tube, into which the sulfur powder and gallium were placed in the low temperature zone (300 ~400 ) and the high temperature zone (850 ~910 ), respectively. Evaporated sulfur (TEM, JEOL-2010F). The Z-contrast images were obtained on an aberration-corrected Nion Ultra

  4. Excited level anisotropy produced by ion-solid and ion-liquid surface interactions

    E-Print Network [OSTI]

    Lee, Chin Shuang

    1977-01-01T23:59:59.000Z

    to the outside of the chambers The gallium was put in a very shallow container (about 1/16") mounted from the bottom flange as shown in Fig 3 ' The container itself was made of tantalum foil which is more ductile than tungsten. Both tantalum and tungsten...

  5. Synthesis, Structure, Bridge-Terminal Exchange Kinetics, and Molecular Orbital Calculations of Pyrazolate-Bridged Digallium Complexes Containing

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Synthesis, Structure, Bridge-Terminal Exchange Kinetics, and Molecular Orbital Calculations gallium atoms.8 Within this perspective, we report the synthesis, structure, bridge-terminal exchange multiplets for the bridging phenyl groups and sharper multiplets for the terminal phenyl groups. The 13C{1H

  6. 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

  7. (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

  8. Studies of local and intermediate range structure in crystalline and amorphouse materials at high pressure using high-energy x-rays.

    SciTech Connect (OSTI)

    Ehm, L.; Antao, M.; Chen, J.; Locke, D. R.; Michel, F. M.; Martin, C. D.; Yu, T.; Lee, P. L.; Chupas, P. J.; Shastri, S. D.; Guo, Q.; Parise, J. B.; Stony Brook Univ.; BNL

    2007-06-01T23:59:59.000Z

    The method of high-energy total elastic X-ray scattering to determine the atomic structure of nanocrystalline, highly disordered, and amorphous materials is presented. The current state of the technique, its potential, and limitations are discussed with two successful studies on the pressure induced phase transition in mackinawite (FeS) and the high-pressure behavior of liquid gallium.

  9. Studies of Local and Intermediate Range Structure in Crystalline and Amorphous Materials at High Pressure Using High-Energy X-rays

    SciTech Connect (OSTI)

    Ehm,L.; Antao, S.; Chen, J.; Locke, D.; Michel, F.; Martin, D.; Yu, T.; Parise, J.; Lee, P.; et al.

    2007-01-01T23:59:59.000Z

    The method of high-energy total elastic X-ray scattering to determine the atomic structure of nanocrystalline, highly disordered, and amorphous materials is presented. The current state of the technique, its potential, and limitations are discussed with two successful studies on the pressure induced phase transition in mackinawite (FeS) and the high-pressure behavior of liquid gallium.

  10. 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

  11. EURODISPLAY 2002 631 P-64: A Comparative Study of Metal Oxide Coated Indium-tin Oxide Anodes

    E-Print Network [OSTI]

    EURODISPLAY 2002 631 P-64: A Comparative Study of Metal Oxide Coated Indium-tin Oxide Anodes and Technology Clear Water Bay, Kowloon, Hong Kong Abstract Indium-tin oxide anodes capped with certain oxides-emitting diodes (OLEDs). The oxides of tin, zinc, praseodymium, yttrium, gallium, terbium and titanium have been

  12. Method of forming particulate materials for thin-film solar cells

    DOE Patents [OSTI]

    Eberspacher, Chris; Pauls, Karen Lea

    2004-11-23T23:59:59.000Z

    A method for preparing particulate materials useful in fabricating thin-film solar cells is disclosed. Particulate materials is prepared by the method include for example materials comprising copper and indium and/or gallium in the form of single-phase, mixed-metal oxide particulates; multi-phase, mixed-metal particulates comprising a metal oxide; and multinary metal particulates.

  13. 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

  14. CRITICAL MINERALS AND EMERGING ENERGY TECHNOLOGIES Statement of

    E-Print Network [OSTI]

    quantities. The most prominent examples are gallium, indium and tellurium in photovoltaic solar cells in Science and Technology. Finally, I briefly describe the activities of a panel on which I serve now, organized under the auspices of the American Physical Society. This panel's work focuses on critical

  15. NATURE COMMUNICATIONS | 3:827 | DOI: 10.1038/ncomms1828 | www.nature.com/naturecommunications 2012 Macmillan Publishers Limited. All rights reserved.

    E-Print Network [OSTI]

    | Published 8 May 2012 DOI:10.1038/ncomms1828 Self-heating is a severe problem for high-power gallium nitride in thermal management. 1 Nano-Device Laboratory, Department of Electrical Engineering, Bourns College velocity of charge carriers and breakdown electrical field, AlGaN/GaN HFETs can operate at extremely high

  16. Metal articles having ultrafine particles dispersed therein

    SciTech Connect (OSTI)

    Alexander, G.B.; Nadkarni, R.A.

    1992-07-28T23:59:59.000Z

    This patent describes a metal article of manufacture. It comprises: a metal selected from the group consisting of copper, silver, gold, lead, tin, nickel, zinc, cobalt, antimony, bismuth, iron, cadmium, chromium, germanium, gallium, selenium, tellurium, mercury, tungsten arsenic, manganese, iridium, indium, ruthenium, rhenium, rhodium, molybdenum, palladium, osmium and platinum; and a plurality of ultrafine particles.

  17. Lattice Parameter Variation in ScGaN Alloy Thin Films on MgO(001) Grown by RF Plasma Molecular Beam Epitaxy

    E-Print Network [OSTI]

    Lattice Parameter Variation in ScGaN Alloy Thin Films on MgO(001) Grown by RF Plasma Molecular Beam ABSTRACT We present the structural and surface characterization of the alloy formation of scandium gallium GaN (w-GaN) spurred much interest in related III-nitrides such as aluminium nitride (Al

  18. GaN nanowires show more 3D piezoelectricity than bulk GaN

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Logo GaN nanowires show more 3D piezoelectricity than bulk GaN admin / January 11, 2012 individual gallium nitride (GaN) nanowires showing strong piezoelectric effect in 3D. This is in spite of the fact that each nanowire only measures 100nm in diameter. While GaN is ubiquitous in optoelectronic

  19. CX-009000: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    "High Quality, Low Cost Bulk Gallium Nitride (GaN) Substrates Grown by the Electrochemical Solution Growth Method CX(s) Applied: A9, B3.6 Date: 08/20/2012 Location(s): Missouri Offices(s): Golden Field Office"

  20. CX-000845: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    25A2445 - Ammonothermal Bulk Gallium Nitride (GaN) Crystal Growth for Energy Efficient LightingCX(s) Applied: B3.6Date: 01/15/2010Location(s): New YorkOffice(s): Advanced Research Projects Agency - Energy

  1. CX-010973: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Advanced Low-Cost Silicon Carbide (SiC) and Gallium Nitride (GaN) Wide Bandgap Inverters for Under-the-Hood Electric Vehicle Traction... CX(s) Applied: B3.6 Date: 09/16/2013 Location(s): Arkansas Offices(s): National Energy Technology Laboratory

  2. GaN Radiation Detectors for Particle Physics and

    E-Print Network [OSTI]

    Glasgow, University of

    GaN Radiation Detectors for Particle Physics and Synchrotron Applications James Paul Grant and monitoring applications. Gallium nitride (GaN) was investigated as a radiation hard particle detector diameter on three epitaxial GaN wafers grown on a sapphire sub- strate. Two of the wafers were obtained

  3. Fabrication of a High-Brightness Blue-Light-Emitting Diode Using a ZnO-Nanowire Array Grown on p-GaN

    E-Print Network [OSTI]

    Wang, Zhong L.

    Fabrication of a High-Brightness Blue-Light-Emitting Diode Using a ZnO-Nanowire Array Grown on p-GaN of metal organic chemical vapor deposition (MOCVD), gallium nitride (GaN) has become the most important GaN nanowires (NWs) have also been fabricated, and nanoLEDs are an active field of research.[5

  4. LA TECHNOLOGIE GAN ET SES APPLICATIONS POUR L'ELECTRONIQUE ROBUSTE, HAUTE FREQUENCE ET DE

    E-Print Network [OSTI]

    Boyer, Edmond

    technologies carbure de silicium (SiC) et nitrure de gallium (GaN) possèdent des qualités intrinsèques réalisation de dispositifs optiques (GaN et alliages InP, Al, P), ce qui autorise un spectre d'applications du visible aux ultraviolets, en émission et en détection : le matériau GaN est le seul qui puisse prétendre à

  5. Sandia National Laboratories: Light Creation Materials

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

    for example ZnO, will be important. AlGaInN Materials LEDs based on gallium nitride (GaN) and ternary alloys with indium (InGaN) and aluminum (AlGaN) as well as quaternary...

  6. CX-010974: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Advanced Low-Cost Silicon Carbide (SiC) and Gallium Nitride (GaN) Wide Bandgap Inverters for Under-the-Hood Electric Vehicle Traction... CX(s) Applied: B3.6 Date: 09/16/2013 Location(s): Arkansas Offices(s): National Energy Technology Laboratory

  7. Watching GaN Nanowires Grow Eric A. Stach,*, Peter J. Pauzauskie, Tevye Kuykendall,

    E-Print Network [OSTI]

    Yang, Peidong

    Watching GaN Nanowires Grow Eric A. Stach,*, Peter J. Pauzauskie, Tevye Kuykendall, Joshua of the growth of GaN nanowires via a self-catalytic vapor-liquid-solid (VLS) mechanism. High temperature thermal decomposition of GaN in a vacuum yields nanoscale Ga liquid droplets and gallium/nitrogen vapor species

  8. Vacancies in GaN bulk and nanowires: effect of self-interaction corrections This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Vacancies in GaN bulk and nanowires: effect of self-interaction corrections This article has been 24 (2012) 255801 (8pp) doi:10.1088/0953-8984/24/25/255801 Vacancies in GaN bulk and nanowires: effect vacancies in gallium nitride (GaN) bulk and nanowires using self-interaction corrected pseudopotentials (SIC

  9. Band-Gap Engineering of Zinc Oxide Colloids via Lattice Substitution with Sulfur Leading to Materials with Advanced Properties for

    E-Print Network [OSTI]

    Nabben, Reinhard

    gap semiconductors like III/V compounds, for instance, gallium nitride (GaN),2 or II/VI compounds bandgap of 3.37 eV at room temperature.7 Thus, one of its most elemental functions is the absorption

  10. Z .Applied Surface Science 154155 2000 439443 www.elsevier.nlrlocaterapsusc

    E-Print Network [OSTI]

    nitride AlN and cubic gallium nitride GaN is studied. The effects of ambient pressure and substrate of cubic AlN and cubic GaN. Specifi- cally, the effects of substrate temperature and ambi- ent pressure temperature on the structure of the AlN and GaN films are systematically investigated. It is shown

  11. 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

  12. Not Your Grandma's Quilt Researchers develop technique to keep cool high-power semiconductor

    E-Print Network [OSTI]

    devices used in wireless applications, traffic lights and electric cars By Sean Nealon On MAY 8, 2012 in everything from traffic lights to electric cars. Gallium Nitride (GaN), a semiconductor material found by the Nano-Device Laboratory research group led byAlexander Balandin, professor of electrical engineering

  13. Cantilever Epitaxy Process Wins R&D 100 Award

    Broader source: Energy.gov [DOE]

    Sandia National Laboratories received an R&D 100 Award from R&D Magazine for development of a new process for growing gallium nitride on an etched sapphire substrate. The process, called cantilever epitaxy, promises to make brighter and more efficient green, blue, and white LEDs.

  14. Phase stable rare earth garnets

    DOE Patents [OSTI]

    Kuntz, Joshua D.; Cherepy, Nerine J.; Roberts, Jeffery J.; Payne, Stephen A.

    2013-06-11T23:59:59.000Z

    A transparent ceramic according to one embodiment includes a rare earth garnet comprising A.sub.hB.sub.iC.sub.jO.sub.12, where h is 3.+-.10%, i is 2.+-.10%, and j is 3.+-.10%. A includes a rare earth element or a mixture of rare earth elements, B includes at least one of aluminum, gallium and scandium, and C includes at least one of aluminum, gallium and scandium, where A is at a dodecahedral site of the garnet, B is at an octahedral site of the garnet, and C is at a tetrahedral site of the garnet. In one embodiment, the rare earth garment has scintillation properties. A radiation detector in one embodiment includes a transparent ceramic as described above and a photo detector optically coupled to the rare earth garnet.

  15. 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.

  16. Low Energy Solar Neutrinos and Spin Flavour Precession

    E-Print Network [OSTI]

    Bhag C. Chauhan; Joao Pulido; R. S. Raghavan

    2005-07-03T23:59:59.000Z

    The possibility that the Gallium data effectively indicates a time modulation of the solar active neutrino flux in possible connection to solar activity is examined on the light of spin flavour precession to sterile neutrinos as a subdominant process in addition to oscillations. We distinguish two sets of Gallium data, relating them to high and low solar activity. Such modulation affects principally the low energy neutrinos ($pp$ and $^7 Be$) so that the effect, if it exists, will become most clear in the forthcoming Borexino and LENS experiments and will provide evidence for a neutrino magnetic moment. Using a model previously developed, we perform two separate fits in relation to low and high activity periods to all solar neutrino data. These fits include the very recent charged current spectrum from the SNO experiment. We also derive the model predictions for Borexino and LENS experiments.

  17. High efficiency InGaN/GaN light emitting diodes with asymmetric triangular multiple quantum wells

    SciTech Connect (OSTI)

    Chang, Chiao-Yun; Li, Hen; Lu, Tien-Chang, E-mail: timtclu@mail.nctu.edu.tw [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan 300 (China)

    2014-03-03T23:59:59.000Z

    In this study, we demonstrated high efficiency InGaN/GaN light emitting diodes (LEDs) with asymmetric triangular multiple quantum wells (MQWs). Asymmetric triangular MQWs not only contribute to uniform carrier distribution in InGaN/GaN MQWs but also yield a low Auger recombination rate. In addition, asymmetric triangular MQWs with gallium face-oriented inclination band profiles can be immune from the polarization charge originating from typical c-plane InGaN/GaN quantum well structures. In the experiment, LEDs incorporated with asymmetric triangular MQWs with gallium face-oriented inclination band profiles exhibited a 60.0% external quantum efficiency at 20?mA and a 27.0% efficiency droop at 100?mA (corresponding to a current density of 69?A/cm{sup 2}), which accounted for an 11.7% efficiency improvement and a 31.1% droop reduction compared with symmetric square quantum well structure LEDs.

  18. Synthesis, morphology and optical properties of GaN and AlGaN semiconductor nanostructures

    SciTech Connect (OSTI)

    Kuppulingam, B., E-mail: drbaskar2009@gmail.com; Singh, Shubra, E-mail: drbaskar2009@gmail.com; Baskar, K., E-mail: drbaskar2009@gmail.com [Crystal Growth Centre, Anna University, Chennai-600025 (India)

    2014-04-24T23:59:59.000Z

    Hexagonal Gallium Nitride (GaN) and Aluminum Gallium Nitride (AlGaN) nanoparticles were synthesized by sol-gel method using Ethylene Diamine Tetra Acetic acid (EDTA) complex route. Powder X-ray diffraction (PXRD) analysis confirms the hexagonal wurtzite structure of GaN and Al{sub 0.25}Ga{sub 0.75}N nanoparticles. Surface morphology and elemental analysis were carried out by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX). The room temperature Photoluminescence (PL) study shows the near band edge emission for GaN at 3.35 eV and at 3.59 eV for AlGaN nanoparticles. The Aluminum (Al) composition of 20% has been obtained from PL emission around 345 nm.

  19. Surface morphology evolution of m-plane (1100) GaN during molecular beam epitaxy growth: Impact of Ga/N ratio, miscut direction, and growth temperature

    SciTech Connect (OSTI)

    Shao Jiayi; Tang Liang; Malis, Oana [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); Edmunds, Colin [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); Gardner, Geoff [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Manfra, Michael [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2013-07-14T23:59:59.000Z

    We present a systematic study of morphology evolution of [1100] m-plane GaN grown by plasma-assisted molecular beam epitaxy on free-standing m-plane substrates with small miscut angles towards the -c [0001] and +c [0001] directions under various gallium to nitrogen (Ga/N) ratios at substrate temperatures T = 720 Degree-Sign C and T = 740 Degree-Sign C. The miscut direction, Ga/N ratio, and growth temperature are all shown to have a dramatic impact on morphology. The observed dependence on miscut direction supports the notion of strong anisotropy in the gallium adatom diffusion barrier and growth kinetics. We demonstrate that precise control of Ga/N ratio and substrate temperature yields atomically smooth morphology on substrates oriented towards +c [0001] as well as the more commonly studied -c [0001] miscut substrates.

  20. Electron transport in the III-V nitride alloys

    SciTech Connect (OSTI)

    Foutz, B.E.; O'Leary, S.K.; Shur, M.S.; Eastman, L.F.

    1999-07-01T23:59:59.000Z

    The authors study electron transport in the alloys of aluminum nitride and gallium nitride and alloys of indium nitride and gallium nitride. In particular, employing Monte Carlo simulations they determine the velocity-field characteristics associated with these alloys for various alloy compositions. They also determine the dependence of the low-field mobility on the alloy composition. They find that while the low-field mobility is a strong function of the alloy composition, the peak and saturation drift velocities exhibit a more mild dependence. Transient electron transport is also considered. They find that the velocity overshoot characteristic is a strong function of the alloy composition. The device implications of these results are discussed.

  1. Experiment Safety Assurance Package for Mixed Oxide Fuel Irradiation in an Average Power Position (I-24) in the Advanced Test Reactor

    SciTech Connect (OSTI)

    J. M . Ryskamp; R. C. Howard; R. C. Pedersen; S. T. Khericha

    1998-10-01T23:59:59.000Z

    The Fissile Material Disposition Program Light Water Reactor Mixed Oxide Fuel Irradiation Test Project Plan details a series of test irradiations designed to investigate the use of weapons-grade plutonium in MOX fuel for light water reactors (LWR) (Cowell 1996a, Cowell 1997a, Thoms 1997a). Commercial MOX fuel has been successfully used in overseas reactors for many years; however, weapons-derived test fuel contains small amounts of gallium (about 2 parts per million). A concern exists that the gallium may migrate out of the fuel and into the clad, inducing embrittlement. For preliminary out-of-pile experiments, Wilson (1997) states that intermetallic compound formation is the principal interaction mechanism between zircaloy cladding and gallium. This interaction is very limited by the low mass of gallium, so problems are not expected with the zircaloy cladding, but an in-pile experiment is needed to confirm the out-of-pile experiments. Ryskamp (1998) provides an overview of this experiment and its documentation. The purpose of this Experiment Safety Assurance Package (ESAP) is to demonstrate the safe irradiation and handling of the mixed uranium and plutonium oxide (MOX) Fuel Average Power Test (APT) experiment as required by Advanced Test Reactor (ATR) Technical Safety Requirement (TSR) 3.9.1 (LMITCO 1998). This ESAP addresses the specific operation of the MOX Fuel APT experiment with respect to the operating envelope for irradiation established by the Upgraded Final Safety Analysis Report (UFSAR) Lockheed Martin Idaho Technologies Company (LMITCO 1997a). Experiment handling activities are discussed herein.

  2. OBSERVATOIRE DE GRENOBLE LABORATOIRE DE GEOPHYSIQUE INTERNE ET TECTONOPHYSIQUE

    E-Print Network [OSTI]

    Aubert, Julien

    thermo-compositionnelle dans la partie de fer liquide du noyau de la Terre est la source d'´energie la´e- sente une premi`ere ´etape vers cet objectif: la mod´elisation de l'´ecou- lement convectif sans champ d'un at modelling the non-magnetic convective flow of a spherical shell of liquid metal (gallium), in the regime

  3. 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

  4. 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

  5. An investigation on reliable passivation of GaP

    E-Print Network [OSTI]

    Greaves King, Carlos A.

    1983-01-01T23:59:59.000Z

    reports the results of a study of sputtered Silicon Nitride 3N4) and Anodic Oxide as passivating techniques for Gallium Phosphide. Anodic Oxide was grown on GaP by anodizing the semiconductor in 30% hydrogen peroxide. The resulting oxide had an index... is therefore needed to prevent degradation due to contamination and charge motion on the surface of the semiconductor [1] . Traditional thermal oxidation techniques used in silicon passivation involves oxidation in high temperature furnaces like the one...

  6. NREL Spurred the Success of Multijunction Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-08-01T23:59:59.000Z

    Many scientists once believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. However, researchers at the National Renewable Energy Laboratory (NREL) thought differently, and they employed GaInP in a material combination that allowed the multijunction cell to flourish. The multijunction cell is now the workhorse that powers satellites and the catalyst for renewed interest in concentrator photovoltaic products.

  7. Synthesis of Low-Melting Metal Oxide and Sulfide Nanowires and Nanobelts

    E-Print Network [OSTI]

    Daraio, Chiara

    such as oxygen/hydrogen mixture for oxides and H2S for sulfides. In the case of b-Ga2O3 and SnO2, a change with the sulfide nanowires suggest that H2S reacts directly at the molten metal surface to form gallium sulfide to either oxygen or H2S at an elevated temperature. EXPERIMENTAL The synthesis of the nanowires

  8. Radiopharmaceuticals for imaging the heart

    DOE Patents [OSTI]

    Green, M.A.; Tsang, B.W.

    1994-06-28T23:59:59.000Z

    Radiopharmaceuticals for imaging myocardial tissues are prepared by forming lipophilic, cationic complexes of radioactive metal ions with metal chelating ligands comprising the Schiff base adducts of triamines and tetraamines with optionally substituted salicylaldehydes. The lipophilic, cationic, radioactive complexes of the invention exhibit high uptake and retention in myocardial tissues. Preferred gallium-68(III) complexes in accordance with this invention can be used to image the heart using positron emission tomography. 6 figures.

  9. Radiopharmaceuticals for imaging the heart

    DOE Patents [OSTI]

    Green, Mark A. (West Lafayette, IN); Tsang, Brenda W. (Lafayette, IN)

    1994-01-01T23:59:59.000Z

    Radiopharmaceuticals for imaging myocardial tissues are prepared by forming lipophilic, cationic complexes of radioactive metal ions with metal chelating ligands comprising the Schiff base adducts of triamines and tetraamines with optionally substituted salicylaldehydes. The lipophilic, cationic, radioactive complexes of the invention exhibit high uptake and retention in myocardial tissues. Preferred gallium-68(III) complexes in accordance with this invention can be used to image the heart using positron emission tomography.

  10. Two dimensional metallic photonic crystals for light trapping and anti-reflective coatings in thermophotovoltaic applications

    SciTech Connect (OSTI)

    Shemelya, Corey; DeMeo, Dante F.; Vandervelde, Thomas E. [The Renewable Energy and Applied Photonics Laboratories, Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States)

    2014-01-13T23:59:59.000Z

    We report the development of a front-side contact design for thermophotovoltaics that utilizes metallic photonic crystals (PhCs). While this front-side grid replacement covers more surface area of the semiconductor, a higher percentage of photons is shown to be converted to usable power in the photodiode. This leads to a 30% increase in the short-circuit current of the gallium antimonide thermophotovoltaic cell.

  11. 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.'

  12. 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.

  13. Hafnium nitride buffer layers for growth of GaN on silicon

    DOE Patents [OSTI]

    Armitage, Robert D.; Weber, Eicke R.

    2005-08-16T23:59:59.000Z

    Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 {character pullout}m. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.

  14. IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 7, JULY 1999 277 18-GHz GaN-Based Power Amplifier

    E-Print Network [OSTI]

    York, Robert A.

    IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 7, JULY 1999 277 1­8-GHz GaN-Based Power, Senior Member, IEEE Abstract-- We report the first gallium nitride (GaN)-based broad-band power amplifier. The circuit was fabricated on an AlN substrate using AlGaN/GaN power high-electron mobil- ity transistors

  15. Exact-exchange-based quasiparticle energy calculations for the band gap, effective masses, and deformation potentials of ScN

    E-Print Network [OSTI]

    of less than 2% to cubic gallium nitride GaN . This makes ScN structurally compatible with the group devices. Alloying ScN with GaN Refs. 9­12 might provide a viable alternative to InGaN alloys for use tunneling spectroscopy and optical-absorption mea- surements, Al-Brithen et al.18 were able to reduce

  16. Ion irradiation induced structural and electrical transition in graphene

    SciTech Connect (OSTI)

    Zhou Yangbo; Wang Yifan; Xu Jun; Fu Qiang; Wu Xiaosong; Yu Dapeng [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Liao Zhimin [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College, Dublin 2 (Ireland); Duesberg, Georg S. [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College, Dublin 2 (Ireland); School of Chemistry, Trinity College, Dublin 2 (Ireland)

    2010-12-21T23:59:59.000Z

    The relationship between the electrical properties and structure evolution of single layer graphene was studied by gradually introducing the gallium ion irradiation. Raman spectrums show a structural transition from nano-crystalline graphene to amorphous carbon as escalating the degree of disorder of the graphene sample, which is in correspondence with the electrical transition from a Boltzmann diffusion transport to a carrier hopping transport. The results show a controllable method to tune the properties of graphene.

  17. 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.

  18. Phosphors containing boron and metals of Group IIIA and IIIB

    DOE Patents [OSTI]

    Setlur, Anant Achyut; Srivastava, Alok Mani; Comanzo, Holly Ann; Manivannan, Venkatesan

    2006-10-31T23:59:59.000Z

    A phosphor comprises: (a) at least a first metal selected from the group consisting of yttrium and elements of lanthanide series other than europium; (b) at least a second metal selected from the group consisting of aluminum, gallium, indium, and scandium; (c) boron; and (d) europium. The phosphor is used in light source that comprises a UV radiation source to convert UV radiation to visible light.

  19. Composition and crystallinity in electrochemically deposited magnetostrictive galfenol (FeGa)

    SciTech Connect (OSTI)

    Estrine, Eliot C., E-mail: estr0042@umn.edu; Hein, Matt; Robbins, William P.; Stadler, Bethanie J. H. [Electrical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-05-07T23:59:59.000Z

    Here, we report the first measurements of magnetostriction as a function of composition for electrodeposited iron-gallium alloys, also known as galfenol. Galfenol is an exciting material due to its large magnetostriction constant (up to 400 ppm) and robust mechanical properties. A wide range of sensors, actuators, and other transducers can be fabricated by taking advantage of galfenol's unique mix of magnetic and mechanical properties. Electrodeposition allows galfenol to be easily integrated into a variety of applications, such as toque sensors with conformal, monolithic active layers. In this work, we examine the underlying factors that influence magnetostriction in electrodeposited galfenol, including crystallinity and composition. Here, we have controlled the film composition, as measured by energy dispersive x-ray spectroscopy, over the range of 5–25% gallium using a single plating bath by varying deposition parameters. This composition range corresponds to the region of largest expected magnetostriction for iron gallium alloys. However, our measured magnetostriction values were significantly lower than the values for single crystal galfenol from literature. The electrodeposited films in this work appeared polycrystalline when measured using x-ray diffraction. When the texture of the film is taken into account, the magnetostriction results closely matched the predicted values. These results show that it is possible to achieve magnetostrictive galfenol thin films over a wide range of compositions using electrodeposition.

  20. High-temperature, structural disorder, phase transitions, and piezoelectric properties of GaPO{sub 4}

    SciTech Connect (OSTI)

    Haines, J.; Cambon, O.; Prudhomme, N.; Fraysse, G.; Keen, D. A.; Chapon, L. C.; Tucker, M. G. [Laboratoire de Physico-Chimie de la Matiere Condensee, UMR CNRS 5617, Universite Montpellier II, Place Eugene Bataillon, cc003, 34095 Montpellier cedex 5 (France); Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom); and ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom)

    2006-01-01T23:59:59.000Z

    Gallium orthophosphate was studied at high temperature up to 1303 K by total neutron scattering and 1173 K by piezoelectric measurements. Rietveld refinements at 1223 K confirm the stability of the structural distortion in the {alpha}-quartz-type phase with an average tilt angle {delta}=18.8 deg. at this temperature. In contrast, reverse Monte Carlo (RMC) refinements of total neutron scattering data indicate that, whereas the degree of structural disorder initially slowly varies over a very large temperature interval in the {alpha}-quartz-type phase, an increase in disorder is observed beginning above 1023 K. Piezoelectric measurements indicate that the quality factor (Q) of GaPO{sub 4} resonators remains stable up to this temperature above which the piezoelectric properties of the material degrade. This degradation can be correlated to the increase in structural disorder. RMC refinements indicate that the high-temperature {beta}-cristobalite-type phase at 1303 K is characterized by significant thermally induced disorder with oxygen atom density forming a continuous ring around the vector joining neighboring gallium and phosphorous atoms. Gallium phosphate may be expected to retain its piezoelectric properties up to within 200 K of the phase transition temperature and as a consequence be used in applications at temperatures slightly above 1000 K.