Sample records for modules single-crystal silicon

  1. Solar cell structure incorporating a novel single crystal silicon material

    DOE Patents [OSTI]

    Pankove, Jacques I. (Princeton, NJ); Wu, Chung P. (Trenton, NJ)

    1983-01-01T23:59:59.000Z

    A novel hydrogen rich single crystal silicon material having a band gap energy greater than 1.1 eV can be fabricated by forming an amorphous region of graded crystallinity in a body of single crystalline silicon and thereafter contacting the region with atomic hydrogen followed by pulsed laser annealing at a sufficient power and for a sufficient duration to recrystallize the region into single crystal silicon without out-gassing the hydrogen. The new material can be used to fabricate semiconductor devices such as single crystal silicon solar cells with surface window regions having a greater band gap energy than that of single crystal silicon without hydrogen.

  2. Technology Development for High-Efficiency Solar Cells and Modules Using Thin (<80 um) Single-Crystal Silicon Wafers Produced by Epitaxy: June 11, 2011 - April 30, 2013

    SciTech Connect (OSTI)

    Ravi, T. S.

    2013-05-01T23:59:59.000Z

    Final technical progress report of Crystal Solar subcontract NEU-31-40054-01. The objective of this 18-month program was to demonstrate the viability of high-efficiency thin (less than 80 um) monocrystalline silicon (Si) solar cells and modules with a low-cost epitaxial growth process.

  3. Thin Single Crystal Silicon Solar Cells on Ceramic Substrates: November 2009 - November 2010

    SciTech Connect (OSTI)

    Kumar, A.; Ravi, K. V.

    2011-06-01T23:59:59.000Z

    In this program we have been developing a technology for fabricating thin (< 50 micrometres) single crystal silicon wafers on foreign substrates. We reverse the conventional approach of depositing or forming silicon on foreign substrates by depositing or forming thick (200 to 400 micrometres) ceramic materials on high quality single crystal silicon films ~ 50 micrometres thick. Our key innovation is the fabrication of thin, refractory, and self-adhering 'handling layers or substrates' on thin epitaxial silicon films in-situ, from powder precursors obtained from low cost raw materials. This 'handling layer' has sufficient strength for device and module processing and fabrication. Successful production of full sized (125 mm X 125 mm) silicon on ceramic wafers with 50 micrometre thick single crystal silicon has been achieved and device process flow developed for solar cell fabrication. Impurity transfer from the ceramic to the silicon during the elevated temperature consolidation process has resulted in very low minority carrier lifetimes and resulting low cell efficiencies. Detailed analysis of minority carrier lifetime, metals analysis and device characterization have been done. A full sized solar cell efficiency of 8% has been demonstrated.

  4. A Constitutive Model for the Mechanical Behavior of Single Crystal Silicon at Elevated Temperature

    E-Print Network [OSTI]

    Moon, H.-S.

    Silicon in single crystal form has been the material of choice for the first demonstration of the MIT microengine project. However, because it has a relatively low melting temperature, silicon is not an ideal material for ...

  5. A variable capacitor made from single crystal silicon fracture surface pairs

    E-Print Network [OSTI]

    Sprunt, Alexander D. (Alexander Dalziel), 1977-

    2005-01-01T23:59:59.000Z

    Complementary and nano-smooth single-crystal-silicon surfaces have been fabricated by deliberately fracturing a weakened portion of a larger structure whose flexural mechanism refines and concentrates an externally applied ...

  6. Elasticity, strength, and toughness of single crystal silicon carbide, ultrananocrystalline diamond, and hydrogen-free tetrahedral amorphous

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Elasticity, strength, and toughness of single crystal silicon carbide, ultrananocrystalline diamond carbide 3C-SiC , ultrananocrystalline diamond, and hydrogen-free tetrahedral amorphous carbon

  7. Bendable single crystal silicon thin film transistors formed by printing on plastic substrates

    E-Print Network [OSTI]

    Rogers, John A.

    Bendable single crystal silicon thin film transistors formed by printing on plastic substrates E on plastic substrates using an efficient dry transfer printing technique. In these devices, free standing-Si is then transferred, to a specific location and with a controlled orientation, onto a thin plastic sheet

  8. Advanced silicon photonic modulators

    E-Print Network [OSTI]

    Sorace, Cheryl M

    2010-01-01T23:59:59.000Z

    Various electrical and optical schemes used in Mach-Zehnder (MZ) silicon plasma dispersion effect modulators are explored. A rib waveguide reverse biased silicon diode modulator is designed, tested and found to operate at ...

  9. Optical constants of silicon carbide for astrophysical applications. II. Extending optical functions from IR to UV using single-crystal absorption spectra

    E-Print Network [OSTI]

    Hofmeister, A M; Goncharov, A F; Speck, A K

    2009-01-01T23:59:59.000Z

    Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal stuctures of silicon carbide (SiC) are presented from 1200--35,000 cm$^{-1}$ ($\\lambda \\sim$ 8--0.28 $\\mu$m) and used to improve the accuracy of optical functions ($n$ and $k$) from the infrared (IR) to the ultraviolet (UV). Comparison with previous $\\lambda \\sim$ 6--20 $\\mu$m thin-film spectra constrains the thickness of the films and verifies that recent IR reflectivity data provide correct values for $k$ in the IR region. We extract $n$ and $k$ needed for radiative transfer models using a new ``difference method'', which utilizes transmission spectra measured from two SiC single-crystals with different thicknesses. This method is ideal for near-IR to visible regions where absorbance and reflectance are low and can be applied to any material. Comparing our results with previous UV measurements of SiC, we distinguish between chemical and structural effects at high frequency. We find that for all spectral re...

  10. OPTICAL CONSTANTS OF SILICON CARBIDE FOR ASTROPHYSICAL APPLICATIONS. II. EXTENDING OPTICAL FUNCTIONS FROM INFRARED TO ULTRAVIOLET USING SINGLE-CRYSTAL ABSORPTION SPECTRA

    SciTech Connect (OSTI)

    Hofmeister, A. M.; Pitman, K. M. [Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130 (United States); Goncharov, A. F. [Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015 (United States); Speck, A. K. [Department of Physics and Astronomy, University of Missouri-Columbia, Columbia, MO 65211 (United States)], E-mail: hofmeist@levee.wustl.edu

    2009-05-10T23:59:59.000Z

    Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal structures of silicon carbide (SiC) are presented from 1200-35000 cm{sup -1} ({lambda} {approx} 8-0.28 {mu}m) and used to improve the accuracy of optical functions (n and k) from the infrared (IR) to the ultraviolet (UV). Comparison with previous {lambda} {approx} 6-20 {mu}m thin-film spectra constrains the thickness of the films and verifies that recent IR reflectivity data provide correct values for k in the IR region. We extract n and k needed for radiative transfer models using a new 'difference method', which utilizes transmission spectra measured from two SiC single-crystals with different thicknesses. This method is ideal for near-IR to visible regions where absorbance and reflectance are low and can be applied to any material. Comparing our results with previous UV measurements of SiC, we distinguish between chemical and structural effects at high frequency. We find that for all spectral regions, 3C ({beta}-SiC) and the E-vector perpendicular c-vector polarization of 6H (a type of {alpha}-SiC) have almost identical optical functions that can be substituted for each other in modeling astronomical environments. Optical functions for E-vector || c-vector of 6H SiC have peaks shifted to lower frequency, permitting identification of this structure below {lambda} {approx} 4 {mu}m. The onset of strong UV absorption for pure SiC occurs near 0.2 {mu}m, but the presence of impurities redshifts the rise to 0.33 {mu}m. Optical functions are similarly impacted. Such large differences in spectral characteristics due to structural and chemical effects should be observable and provide a means to distinguish chemical variation of SiC dust in space.

  11. Single crystal neutron diffraction study of lattice and magnetic structures of 5M modulated Ni2Mn1.14Ga0.86

    SciTech Connect (OSTI)

    Pramanick, Abhijit [ORNL] [ORNL; Wang, Xiaoping [ORNL] [ORNL; An, Ke [ORNL] [ORNL; Stoica, Alexandru Dan [ORNL] [ORNL; Hoffmann, Christina [ORNL] [ORNL; Wang, Xun-Li [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    A comprehensive description of the crystal and magnetic structures of Ni-Mn-Ga magnetic shape memory alloys is important to understand the physical origins of their magnetoelastic properties. These structural details for an off-stoichiometric Ni2Mn1.14Ga0.86 alloy have been obtained from refinement of high-resolution single crystal neutron diffraction data following a (3+1)-dimensional superspace formalism. In particular, the structure adopts a P2/m( 0 )00 (3+1)-D superspace symmetry with the following fundamental lattice parameters: a=4.255(4) , b=5.613(4) , c=4.216(3) , a commensurate periodicity of 5M and a modulation wave vector of . The magnetic moments are aligned along the b-axis. The modulations for atomic site displacements, site occupancies and magnetic moments are elucidated from a (3+1)-D refinement of the neutron diffraction data. In addition to atomic displacements corresponding to shear waves along <110>, distortions of Ni-centric tetrahedra are also evident. Physical interpretations for the different structural distortions and their relationship with magnetic properties are discussed.

  12. PHOTOCATALYTIC AND PHOTOELECTROCHEMICAL HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS

    E-Print Network [OSTI]

    Wagner, F.T.

    2012-01-01T23:59:59.000Z

    HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS F.HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS

  13. X-ray diffraction on the X-cut of a Ca{sub 3}TaGa{sub 3}Si{sub 2}O{sub 14} single crystal modulated by a surface acoustic wave

    SciTech Connect (OSTI)

    Irzhak, D., E-mail: irzhak@iptm.ru; Roshchupkin, D., E-mail: rochtch@iptm.ru [Institute of Microelectronics Technology and High-Purity Materials Russian Academy of Sciences, Chernogolovka 142432 (Russian Federation)

    2014-06-28T23:59:59.000Z

    The result of X-ray diffraction study on a single crystal of the calcium-gallogermanate family Ca{sub 3}TaGa{sub 3}Si{sub 2}O{sub 14} (CTGS) modulated by a surface acoustic wave (SAW) is presented. The power flow angle for SAW propagating along the X{sub 2} axis of the X-cut in CTGS was measured. The rocking curves for the CTGS crystal were recorded at different amplitudes of an input high frequency electric signal on interdigital transducer used to excite a SAW. Based on the data obtained, intensity dependence of diffraction satellites on the amplitude of electric signal exciting a SAW was built. Numerical simulation of the crystal rocking curves and dependence of diffraction satellite intensities on the SAW amplitude enabled the selection of a set of material constants at which the most complete coincidence of experimental and calculated results is observed.

  14. Cryogenic Silicon Microstrip Detector Modules for LHC

    E-Print Network [OSTI]

    Perea-Solano, B

    2004-01-01T23:59:59.000Z

    CERN is presently constructing the LHC, which will produce collisions of 7 TeV protons in 4 interaction points at a design luminosity of 1034 cm-2 s-1. The radiation dose resulting from the operation at high luminosity will cause a serious deterioration of the silicon tracker performance. The state-of-art silicon microstrip detectors can tolerate a fluence of about 3 1014 cm-2 of hadrons or charged leptons. This is insufficient, however, for long-term operation in the central parts of the LHC trackers, in particular after the possible luminosity upgrade of the LHC. By operating the detectors at cryogenic temperatures the radiation hardness can be improved by a factor 10. This work proposes a cryogenic microstrip detector module concept which has the features required for the microstrip trackers of the upgraded LHC experiments at CERN. The module can hold an edgeless sensor, being a good candidate for improved luminosity and total cross-section measurements in the ATLAS, CMS and TOTEM experiments. The design o...

  15. Photon tunnelling microscopy of polyethylene single crystals

    E-Print Network [OSTI]

    Srinivasarao, Mohan

    Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

  16. IMPROVED SPECTRAL RESPONSE OF SILICONE ENCAPSULANTED PHOTOVOLTAIC MODULES

    E-Print Network [OSTI]

    IMPROVED SPECTRAL RESPONSE OF SILICONE ENCAPSULANTED PHOTOVOLTAIC MODULES Nick E. Powell 1* , Byung the benefit of using optically superior silicone encapsulant materials over the incumbent ethylene vinyl in the UV region of the solar spectrum. Single cell mini-modules were prepared using two different

  17. Nanoscale Calorimetry of Isolated Polyethylene Single Crystals

    E-Print Network [OSTI]

    Allen, Leslie H.

    Nanoscale Calorimetry of Isolated Polyethylene Single Crystals A. T. KWAN, M. YU. EFREMOV, E. A-film differential scanning calorimetry to investigate the melt- ing of isolated polyethylene single crystals of lamellar single crystals of polyethylene (PE). We obtain thickness, diffraction, and calorimetry data

  18. Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells

    E-Print Network [OSTI]

    Schiff, Eric A.

    Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells Kai Zhu a,1 , E Solar, Toano, VA 23168, USA Abstract We report infrared depletion modulation spectra for near an infrared modulation spectroscopy technique that probes the optical spectra of dopants and defects

  19. Ames Lab 101: Single Crystal Growth

    ScienceCinema (OSTI)

    Schlagel, Deborah

    2014-06-04T23:59:59.000Z

    Ames Laboratory scientist Deborah Schlagel talks about the Lab's research in growing single crystals of various metals and alloys. The single crystal samples are vital to researchers' understanding of the characteristics of a materials and what gives these materials their particular properties.

  20. Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demsy and Sajeev John

    E-Print Network [OSTI]

    John, Sajeev

    Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demésy and Sajeev://jap.aip.org/about/rights_and_permissions #12;Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demesya

  1. Performance of the CLAS12 Silicon Vertex Tracker modules

    SciTech Connect (OSTI)

    Antonioli, Mary Ann [JLAB; Boiarinov, Serguie; Bonneau, Peter R. [JLAB; Elouadrhiri, Latifa [JLAB; Eng, Brian J. [JLAB; Gotra, Yuri N. [JLAB; Kurbatov, Evgeny O. [Moscow State U.; Leffel, Mindy A. [JLAB; Mandal, Saptarshi [JLAB; McMullen, Marc E. [JLAB; Merkin, Mikhail M. [Moscow State U.; Raydo, Benjamin J. [JLAB; Teachey, Robert W, [JLAB; Tucker, Ross J. [Arizona State U.; Ungaro, Maurizio [JLAB; Yegneswaran, Amrit S. [JLAB; Ziegler, Veronique [JLAB

    2013-12-01T23:59:59.000Z

    For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156{micro}m, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements.

  2. Test-to-Failure of Crystalline Silicon Modules: Preprint

    SciTech Connect (OSTI)

    Hacke, P.; Terwilliger, K.; Glick, S.; Trudell, D.; Bosco, N.; Johnston, S.; Kurtz, S. R.

    2010-10-01T23:59:59.000Z

    Accelerated lifetime testing of five crystalline silicon module designs was carried out according to the Terrestrial Photovoltaic Module Accelerated Test-to-Failure Protocol. This protocol compares the reliability of various module constructions on a quantitative basis. The modules under test are subdivided into three accelerated lifetime testing paths: 85..deg..C/85% relative humidity with system bias, thermal cycling between ?40..deg..C and 85..deg..C, and a path that alternates between damp heat and thermal cycling. The most severe stressor is damp heat with system bias applied to simulate the voltages that modules experience when connected in an array. Positive 600 V applied to the active layer with respect to the grounded module frame accelerates corrosion of the silver grid fingers and degrades the silicon nitride antireflective coating on the cells. Dark I-V curve fitting indicates increased series resistance and saturation current around the maximum power point; however, an improvement in junction recombination characteristics is obtained. Shunt paths and cell-metallization interface failures are seen developing in the silicon cells as determined by electroluminescence, thermal imaging, and I-V curves in the case of negative 600 V bias applied to the active layer. Ability to withstand electrolytic corrosion, moisture ingress, and ion drift under system voltage bias are differentiated.

  3. Solar power conversion efficiency in modulated silicon nanowire photonic Alexei Deinega and Sajeev John

    E-Print Network [OSTI]

    John, Sajeev

    Solar power conversion efficiency in modulated silicon nanowire photonic crystals Alexei Deinega://jap.aip.org/about/rights_and_permissions #12;Solar power conversion efficiency in modulated silicon nanowire photonic crystals Alexei Deinegaa that using only 1 lm of silicon, sculpted in the form of a modulated nanowire photonic crystal, solar power

  4. Monolithic amorphous silicon modules on continuous polymer substrate

    SciTech Connect (OSTI)

    Grimmer, D.P. (Iowa Thin Film Technologies, Inc., Ames, IA (United States))

    1992-03-01T23:59:59.000Z

    This report examines manufacturing monolithic amorphous silicon modules on a continuous polymer substrate. Module production costs can be reduced by increasing module performance, expanding production, and improving and modifying production processes. Material costs can be reduced by developing processes that use a 1-mil polyimide substrate and multilayers of low-cost material for the front encapsulant. Research to speed up a-Si and ZnO deposition rates is needed to improve throughputs. To keep throughput rates compatible with depositions, multibeam fiber optic delivery systems for laser scribing can be used. However, mechanical scribing systems promise even higher throughputs. Tandem cells and production experience can increase device efficiency and stability. Two alternative manufacturing processes are described: (1) wet etching and sheet handling and (2) wet etching and roll-to-roll fabrication.

  5. Neutron detection with single crystal organic scintillators

    SciTech Connect (OSTI)

    Zaitseva, N; Newby, J; Hamel, S; Carman, L; Faust, M; Lordi, V; Cherepy, N; Stoeffl, W; Payne, S

    2009-07-15T23:59:59.000Z

    Detection of high-energy neutrons in the presence of gamma radiation background utilizes pulse-shape discrimination (PSD) phenomena in organics studied previously only with limited number of materials, mostly liquid scintillators and single crystal stilbene. The current paper presents the results obtained with broader varieties of luminescent organic single crystals. The studies involve experimental tools of crystal growth and material characterization in combination with the advanced computer modeling, with the final goal of better understanding the relevance between the nature of the organic materials and their PSD properties. Special consideration is given to the factors that may diminish or even completely obscure the PSD properties in scintillating crystals. Among such factors are molecular and crystallographic structures that determine exchange coupling and exciton mobility in organic materials and the impurity effect discussed on the examples of trans-stilbene, bibenzyl, 9,10-diphenylanthracene and diphenylacetylene.

  6. SLID Interconnected n-in-p Pixel Modules with 75 Micrometer Thin Silicon Sensors

    E-Print Network [OSTI]

    Andricek,L; Macchiolo,A; Moser,H-G; Nisius,R; Richter,R.H; Terzo,S; Weigell,P

    2014-01-01T23:59:59.000Z

    The performance of pixel modules built from 75 micrometer thin silicon sensors and ATLAS read-out chips employing the Solid

  7. Specific features of utilizing bismuth antimony chalcogenide single crystals in miniature coolers

    SciTech Connect (OSTI)

    Semenyuk, V.A. [Odessa State Academy of Cold, (Ukraine); Ivanova, L.D.; Svechnikova, T.E. [Baikov Institute of Metallurgy, Moscow (Russian Federation)

    1995-01-01T23:59:59.000Z

    A procedure for growing perfect single crystals of bismuth antimony chalcogenide solid solutions by the Czochralski technique with melt feeding from a floating crucible was developed at the Baikov Institute of Metallurgy. Given that the single crystals in question readily split along the cleavage planes, the problem of acceptable yield of suitable products in the manufacture of thermoelements and cooling modules arises. To solve this problem, investigations were undertaken along two lines: (1) development of nondestructive, damage-free technologies; and (2) development of methods for making low-resistance antidiffusion contacts on the end faces of the thermoelements.

  8. Boron Carbide and Silicon Oxide Hetero-nanonecklaces via Temperature Modulation

    E-Print Network [OSTI]

    Gao, Hongjun

    Boron Carbide and Silicon Oxide Hetero-nanonecklaces via Temperature Modulation Jifa Tian, Xingjun ReceiVed April 23, 2008 ABSTRACT: Boron carbide and silicon oxide (BCSiO) hetero-nanonecklaces have been-500 nm silicon oxide nanoballs onto 20-30 nm boron carbide nanowires. Synthetic analysis shows that a two

  9. amorphous silicon modules: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 10 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  10. Halide electroadsorption on single crystal surfaces

    SciTech Connect (OSTI)

    Ocko, B.M. [Brookhaven National Lab., Upton, NY (United States). Dept. of Physics; Wandlowski, T. [Univ. of Ulm (Germany). Dept. of Electrochemistry

    1997-07-01T23:59:59.000Z

    The structure and phase behavior of halides have been investigated on single crystals of Ag and Au using synchrotron x-ray scattering techniques. The adlayer coverages are potential dependent. For all halides studied the authors found that with increasing potential, at a critical potential, a disordered adlayer transforms into an ordered structure. Often these ordered phases are incommensurate and exhibit potential-dependent lateral separations (electrocompression). The authors have analyzed the electrocompression in terms of a model which includes lateral interactions and partial charge. A continuous compression is not observed for Br on Ag(100). Rather, they find that the adsorption is site-specific (lattice gas) in both the ordered and disordered phases. The coverage increases with increasing potential and at a critical potential the disordered phase transforms to a well-ordered commensurate structure.

  11. Infrared Charge-Modulation Spectroscopy of Defects in Phosphorus Doped Amorphous Silicon

    E-Print Network [OSTI]

    Schiff, Eric A.

    Infrared Charge-Modulation Spectroscopy of Defects in Phosphorus Doped Amorphous Silicon KAI ZHU Solar, Toano, VA 23168 USA ABSTRACT We present infrared charge-modulation absorption spectra have been developing an infrared modulation spectroscopy technique that probes the optical spectra

  12. Single-crystal germanium growth on amorphous silicon

    E-Print Network [OSTI]

    McComber, Kevin A

    2011-01-01T23:59:59.000Z

    The integration of photonics with electronics has emerged as a leading platform for microprocessor technology and the continuation of Moore's Law. As electronic device dimensions shrink, electronic signals encounter crippling ...

  13. The effect of encapsulation on the reflectance of photovoltaic modules using textured multicrystalline-silicon solar cells

    SciTech Connect (OSTI)

    Gee, J.M.; Schubert, W.K.; Tardy, H.L.; Hund, T.D. [Sandia National Labs., Albuquerque, NM (United States); Robison, G. [Semiconductor Assembly Network, Prescott Valley, AZ (United States)

    1995-01-01T23:59:59.000Z

    Texturing multicrystalline-silicon cells is a promising technique for reducing reflectance losses. We investigated two methods for texturing multicrystalline-silicon solar cells - anisotropic chemical etch and mechanical dicing saw. Our work emphasized reducing reflectance in the encapsulated module by using optical confinement in the module. We found that optical confinement in the module is very important in the optimization of texture geometries.

  14. Epitaxial electrodeposition of freestanding large area single crystal substrates

    SciTech Connect (OSTI)

    Shin, Jae Wook; Standley, Adam; Chason, Eric [Brown University, Box D, Providence, Rhode Island 02912 (United States)

    2007-06-25T23:59:59.000Z

    The authors report on a method for producing freestanding single crystal metal films over large areas using electrodeposition and selective etching. The method can be turned into an inexpensive continuous process for making long ribbons or a large area of single crystal films. Results from a 5x5 mm{sup 2} Ni single crystal film using electron backscattering pattern pole figures and x-ray diffraction demonstrate that the quality of material produced is equivalent to the initial substrate without annealing or polishing.

  15. A WDM Silicon Photonic Transmitter based on Carrier-Injection Microring Modulators

    E-Print Network [OSTI]

    Palermo, Sam

    A WDM Silicon Photonic Transmitter based on Carrier- Injection Microring Modulators Chin-Hui Chen1 photonic transmitter based on carrier-injection type microring modulators. Resonant wavelengths can be adjusted by both thermal heaters and bias tuning. OCIS codes: (200.4650) Optical interconnects; (250

  16. Constitutive modeling of creep of single crystal superalloys

    E-Print Network [OSTI]

    Prasad, Sharat Chand

    2006-10-30T23:59:59.000Z

    of , and oriented single crystal nickel based su- peralloys for a range of temperatures. The predictions of the theory match well with the available experimental data for CMSX-4. The constitutive model is also imple- mented as a User...

  17. Synthesis and physical characterization of thermoelectric single crystals

    E-Print Network [OSTI]

    Porras Pérez Guerrero, Juan Pablo

    2012-01-01T23:59:59.000Z

    There is much current interest in thermoelectric devices for sustainable energy. This thesis describes a research project on the synthesis and physical characterization of thermoelectric single crystals. 1In?Se?-[delta] ...

  18. Transverse acoustic actuation of Ni-Mn-Ga single crystals

    E-Print Network [OSTI]

    Simon, Jesse Matthew

    2007-01-01T23:59:59.000Z

    Two methods for the transverse acoustic actuation of {110}-cut Ni-Mn-Ga single crystals are discussed. In this actuation mode, crystals are used that have the {110}- type twinning planes parallel to the base of the crystal. ...

  19. Superconducting Proximity Effect in Single-Crystal Nanowires

    E-Print Network [OSTI]

    Liu, Haidong

    2010-07-14T23:59:59.000Z

    This dissertation describes experimental studies of the superconducting proximity effect in single-crystal Pb, Sn, and Zn nanowires of lengths up to 60 um, with both ends of the nanowires in contact with macroscopic electrodes that are either...

  20. al single crystal: Topics by E-print Network

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

    14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Low-Leakage Superconducting Tunnel Junctions with a Single-Crystal Al2O3 Barrier* Computer Technologies and...

  1. al single crystals: Topics by E-print Network

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

    14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Low-Leakage Superconducting Tunnel Junctions with a Single-Crystal Al2O3 Barrier* Computer Technologies and...

  2. Study of photomodulated reflectance in 6H-SiC single crystals

    SciTech Connect (OSTI)

    Gruzintsev, A. N., E-mail: gran@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and Ultra-High-Purity Materials (Russian Federation)

    2013-04-15T23:59:59.000Z

    The effect of ultraviolet irradiation of the surface of silicon-carbide (6H-SiC) single crystals on their optical reflectivity in the visible and violet spectral regions is studied. It is shown that the photoreflection-signal intensity is maximal, if the light beam is incident at the Brewster angle and polarized parallel to the plane of incidence. The relative change induced in the refractive index of the surface layers of a crystal (10{sup -3}) upon exposure to nitrogen laser radiation, caused by the generation of nonequilibrium free charge carriers in the conduction band of the material, is established.

  3. Single crystal Processing and magnetic properties of gadolinium nickel

    SciTech Connect (OSTI)

    Shreve, Andrew John [Ames Laboratory

    2012-11-02T23:59:59.000Z

    GdNi is a rare earth intermetallic material that exhibits very interesting magnetic properties. Spontaneous magnetostriction occurs in GdNi at T{sub C}, on the order of 8000ppm strain along the c-axis and only until very recently the mechanism causing this giant magnetostriction was not understood. In order to learn more about the electronic and magnetic structure of GdNi, single crystals are required for anisotropic magnetic property measurements. Single crystal processing is quite challenging for GdNi though since the rare-earth transition-metal composition yields a very reactive intermetallic compound. Many crystal growth methods are pursued in this study including crucible free methods, precipitation growths, and specially developed Bridgman crucibles. A plasma-sprayed Gd{sub 2}O{sub 3} W-backed Bridgman crucible was found to be the best means of GdNi single crystal processing. With a source of high-quality single crystals, many magnetization measurements were collected to reveal the magnetic structure of GdNi. Heat capacity and the magnetocaloric effect are also measured on a single crystal sample. The result is a thorough report on high quality single crystal processing and the magnetic properties of GdNi.

  4. 14th Workshop on Crystalline Silicon Solar Cells& Modules: Materials and Processes; Summary of Discussion Sessions

    SciTech Connect (OSTI)

    Sopori, B.; Tan, T.; Sinton, R.; Swanson, D.

    2004-10-01T23:59:59.000Z

    The 14th Workshop discussion sessions addressed funding needs for Si research and for R&D to enhance U.S. PV manufacturing. The wrap-up session specifically addressed topics for the new university silicon program. The theme of the workshop, Crystalline Silicon Solar Cells: Leapfrogging the Barriers, was selected to reflect the astounding progress in Si PV technology during last three decades, despite a host of barriers and bottlenecks. A combination of oral, poster, and discussion sessions addressed recent advances in crystal growth technology, new cell structures and doping methods, silicon feedstock issues, hydrogen passivation and fire through metallization, and module issues/reliability. The following oral/discussion sessions were conducted: (1) Technology Update; (2) Defects and Impurities in Si/Discussion; (3) Rump Session; (4) Module Issues and Reliability/Discussion; (5) Silicon Feedstock/Discussion; (6) Novel Doping, Cells, and Hetero-Structure Designs/Discussion; (7) Metallization/Silicon Nitride Processing/Discussion; (8) Hydrogen Passivation/Discussion; (9) Characterization/Discussion; and (10) Wrap-Up. This year's workshop lasted three and a half days and, for the first time, included a session on Si modules. A rump session was held on the evening of August 8, which addressed efficiency expectations and challenges of c Si solar cells/modules. Richard King of DOE and Daren Dance of Wright Williams& Kelly (formerly of Sematech) spoke at two of the luncheon sessions. Eleven students received Graduate Student Awards from funds contributed by the PV industry.

  5. Buried oxide layer in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir, TN)

    2001-01-01T23:59:59.000Z

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  6. Elastic constants of single crystal Hastelloy X at elevated temperatures

    SciTech Connect (OSTI)

    Canistraro, H.A. [Univ. of Hartford, CT (United States). Dept. of Mechanical and Audio Engineering Technology; Jordan, E.H.; Shi Shixiang [Univ. of Connecticut, Storrs, CT (United States); Favrow, L.H.; Reed, F.A. [United Technologies Research Center, East Hartford, CT (United States)

    1998-07-01T23:59:59.000Z

    An acoustic time of flight technique is described in detail for measuring the elastic constants of cubic single crystals that allows for the constants to be determined at elevated temperature. Although the overall technique is not new, various aspects of the present work may prove extremely useful to others interested in finding these values, especially for aerospace materials applications. Elastic constants were determined for the nickel based alloy, Hastelloy X from room temperature to 1,000 C. Accurate elastic constants were needed as part of an effort to predict both polycrystal mechanical properties and the nature of grain induced heterogeneous mechanical response. The increased accuracy of the acoustically determined constants resulted in up to a 15% change in the predicted stresses in individual grains. These results indicate that the use of elastic single crystal constants of pure nickel as an approximation for the constants of gas turbine single crystal alloys, which is often done today, is inaccurate.

  7. CRACK STATISTIC OF CRYSTALLINE SILICON PHOTOVOLTAIC MODULES M. Kntges1

    E-Print Network [OSTI]

    the risk of cracks, as well as for statistical power loss assessment. Keywords: PV module, micro cracks separation, thus resulting in inactive cell parts. For this special case a clear assessment of the power loss this gap and provide a first statistic of cracks in PV modules for future power loss assessment

  8. SINGLE CRYSTAL NIOBIUM TUBES FOR PARTICLE COLLIDERS ACCELERATOR CAVITIES

    SciTech Connect (OSTI)

    MURPHY, JAMES E [University of Nevada, Reno] [University of Nevada, Reno

    2013-02-28T23:59:59.000Z

    The objective of this research project is to produce single crystal niobium (Nb) tubes for use as particle accelerator cavities for the Fermi laboratory’s International Linear Collider project. Single crystal Nb tubes may have superior performance compared to a polycrystalline tubes because the absence of grain boundaries may permit the use of higher accelerating voltages. In addition, Nb tubes that are subjected to the high temperature, high vacuum crystallization process are very pure and well annealed. Any impurity with a significantly higher vapor pressure than Nb should be decreased by the relatively long exposure at high temperature to the high vacuum environment. After application of the single crystal process, the surfaces of the Nb tubes are bright and shiny, and the tube resembles an electro polished Nb tube. For these reasons, there is interest in single crystal Nb tubes and in a process that will produce single crystal tubes. To convert a polycrystalline niobium tube into a single crystal, the tube is heated to within a few hundred ?C of the melting temperature of niobium, which is 2477 ?C. RF heating is used to rapidly heat the tube in a narrow zone and after reaching the operating temperature, the hot zone is slowly passed along the length of the tube. For crystallization tests with Nb tubes, the traverse rate was in the range of 1-10 cm per hour. All the crystallization tests in this study were performed in a water-cooled, stainless steel chamber under a vacuum of 5 x10-6 torr or better. In earliest tests of the single crystal growth process, the Nb tubes had an OD of 1.9 cm and a wall thickness of 0.15 mm. With these relatively small Nb tubes, the single crystal process was always successful in producing single crystal tubes. In these early tests, the operating temperature was normally maintained at 2200 ?C, and the traverse rate was 5 cm per hour. In the next test series, the Nb tube size was increased to 3.8 cm OD and the wall thickness was increased 0.18 mm and eventually to 0.21 mm. Again, with these larger tubes, single crystal tubes were usually produced by the crystallization process. The power supply was generally operated at full output during these tests, and the traverse rate was 5 cm per hour. In a few tests, the traverse rate was increased to 10 cm per hour, and at the faster traverse rate, single crystal growth was not achieved. In these tests with a faster traverse rate, it was thought that the tube was not heated to a high enough temperature to achieve single crystal growth. In the next series of tests, the tube OD was unchanged at 3.8 cm and the wall thickness was increased to 0.30 mm. The increased wall thickness made it difficult to reach an operating temperature above 2,000 ?C, and although the single crystal process caused a large increase in the crystal grains, no single crystal tubes were produced. It was assumed that the operating temperature in these tests was not high enough to achieve single crystal growth. In FY 2012, a larger power supply was purchased and installed. With the new power supply, temperatures above the melting point of Nb were easily obtained regardless of the tube thickness. A series of crystallization tests was initiated to determine if indeed the operating temperature of the previous tests was too low to achieve single crystal growth. For these tests, the Nb tube OD remained at 3.8 cm and the wall thickness was 0.30 mm. The first test had an operating temperature of 2,000 ?C. and the operating temperature was increased by 50 ?C increments for each successive test. The final test was very near the Nb melting temperature, and indeed, the Nb tube eventually melted in the center of the tube. These tests showed that higher temperatures did yield larger grain sizes if the traverse rate was held constant at 5 cm per hour, but no single crystal tubes were produced even at the highest operating temperature. In addition, slowing the traverse rate to as low as 1 cm per hour did not yield a single crystal tube regardless of operating temperature. At this time, it

  9. Apparatus And Method For Producing Single Crystal Metallic Objects

    DOE Patents [OSTI]

    Huang, Shyh-Chin (Latham, NY); Gigliotti, Jr., Michael Francis X. (Scotia, NY); Rutkowski, Stephen Francis (Duanesburg, NY); Petterson, Roger John (Fultonville, NY); Svec, Paul Steven (Scotia, NY)

    2006-03-14T23:59:59.000Z

    A mold is provided for enabling casting of single crystal metallic articles including a part-defining cavity, a sorter passage positioned vertically beneath and in fluid communication with the part-defining cavity, and a seed cavity positioned vertically beneath and in fluid communication with the sorter passage. The sorter passage includes a shape suitable for encouraging a single crystal structure in solidifying molten metal. Additionally, a portion of the mold between the sorter passage and the part-defining cavity includes a notch for facilitating breakage of a cast article proximate the notch during thermal stress build-up, so as to prevent mold breakage or the inclusion of part defects.

  10. Method for harvesting single crystals from a peritectic melt

    DOE Patents [OSTI]

    Todt, V.R.; Sengupta, S.; Shi, D.

    1996-08-27T23:59:59.000Z

    A method of preparing single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals unmelted, allowing the wicking away of the peritectic liquid. 2 figs.

  11. Method for harvesting single crystals from a peritectic melt

    DOE Patents [OSTI]

    Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

    1996-01-01T23:59:59.000Z

    A method of preparing single crystals. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals unmelted, allowing the wicking away of the peritectic liquid.

  12. Method for harvesting rare earth barium copper oxide single crystals

    DOE Patents [OSTI]

    Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

    1996-01-01T23:59:59.000Z

    A method of preparing high temperature superconductor single crystals. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid.

  13. Radiation-assisted Frenkel-Poole transport in single-crystal diamond

    SciTech Connect (OSTI)

    Girolami, M.; Bellucci, A.; Calvani, P.; Flammini, R.; Trucchi, D. M. [CNR-IMIP, Institute of Inorganic Methodologies and Plasmas, National Research Council, Via Salaria km 29.300, 00015 Monterotondo Stazione, Rome (Italy)] [CNR-IMIP, Institute of Inorganic Methodologies and Plasmas, National Research Council, Via Salaria km 29.300, 00015 Monterotondo Stazione, Rome (Italy)

    2013-08-19T23:59:59.000Z

    The measurement of the density of occupied states as a function of the applied electric field, performed on single-crystal chemical vapour deposition diamond by x-ray modulated photocurrent technique, is reported. Two regimes of non-linear charge transport were observed: a classical Frenkel-Poole (FP) process at high electric fields (>6800 V/cm), and a radiation-assisted transport mechanism at intermediate electric fields (2000 to 6800 V/cm), consisting of a double-step process in which the direct re-emission into the extended band occurs following multiple photo-induced FP-like hopping transitions.

  14. Characterization of Multicrystalline Silicon Modules with System Bias Voltage Applied in Damp Heat

    SciTech Connect (OSTI)

    Hacke, P.; Kempe, M.; Terwilliger, K.; Glick, S.; Call, N.; Johnston, S.; Kurtz, S.

    2011-07-01T23:59:59.000Z

    As it is considered economically favorable to serially connect modules to build arrays with high system voltage, it is necessary to explore potential long-term degradation mechanisms the modules may incur under such electrical potential. We performed accelerated lifetime testing of multicrystalline silicon PV modules in 85 degrees C/ 85% relative humidity and 45 degrees C/ 30% relative humidity while placing the active layer in either positive or negative 600 V bias with respect to the grounded module frame. Negative bias applied to the active layer in some cases leads to more rapid and catastrophic module power degradation. This is associated with significant shunting of individual cells as indicated by electroluminescence, thermal imaging, and I-V curves. Mass spectroscopy results support ion migration as one of the causes. Electrolytic corrosion is seen occurring with the silicon nitride antireflective coating and silver gridlines, and there is ionic transport of metallization at the encapsulant interface observed with damp heat and applied bias. Leakage current and module degradation is found to be highly dependent upon the module construction, with factors such as encapsulant and front glass resistivity affecting performance. Measured leakage currents range from about the same seen in published reports of modules deployed in Florida (USA) and is accelerated to up to 100 times higher in the environmental chamber testing.

  15. ATLAS ID Upgrade R&D Plan: Development of a Short-Strip Silicon Detector Module

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    ATLAS ID Upgrade R&D Plan: Development of a Short-Strip Silicon Detector Module and a Frontend of the optimum technology and layout of the tracking detectors for the upgraded ATLAS ID. The goal for the intermediate tracking region in the upgraded ATLAS ID. We anticipate that much of the work would then also

  16. Low temperature magnetic transitions of single crystal HoBi

    SciTech Connect (OSTI)

    Fente, A. [Universidad Autonoma de Madrid; Suderow, H. [Universidad Autonoma de Madrid; Vieira, S. [Universidad Autonoma de Madrid; Nemes, N. M. [Instituto de Ciencia de Materiales de Madrid; Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid; Budko, Sergei L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

    2013-09-04T23:59:59.000Z

    We present resistivity, specific heat and magnetization measurements in high quality single crystals of HoBi, with a residual resistivity ratio of 126. We find, from the temperature and field dependence of the magnetization, an antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields, into a series of up to five metamagnetic phases.

  17. NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS

    E-Print Network [OSTI]

    Allen, Leslie H.

    #12;NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS BY ALEX TAN KWAN B.S., Stanford) device, the nanocalorimeter, it was possible to investigate the melting of isolated polyethylene (PE, a simple Ni-foil calorimeter, to measure the heat capacity of a thin polyethylene film to verify

  18. Research on stable, high-efficiency, amorphous silicon multijunction modules

    SciTech Connect (OSTI)

    Catalano, A.; Bennet, M.; Chen, L.; Fieselmann, B.; Li, Y.; Newton, J.; Podlesny, R.; Wiedeman, S.; Yang, L. (Solarex Corp., Newtown, PA (United States). Thin Film Div.)

    1991-08-01T23:59:59.000Z

    The present effort seeks to develop modules with a stabilized performance of 8.8% aperture area conversion after 600 hours light exposure (AM1.5) at 50{degrees}C in modules with aperture areas over 900 cm{sup 2}. Good progress towards this goal has been obtained with the demonstration of 9.8% initial performance in a submodule incorporating devices with relatively thin middle junction i-layer thickness of 4000{Angstrom}. Devices with this design have been shown to lose about 10% of their initial performance after 1000 hours of exposure. Modules lose between 18--23% largely due to light induced shunting, probably related to the contact metallization. Achieving long-term stabilized efficiencies of 12% or more requires substantial improvements in materials and devices. Our analysis has shown that substantial optical losses occur at both front and rear contacts which we hope to address with ZnO films prepared by CVD and sputtering processes now under development. Further progress is doped layers and alloys are also needed. Fundamental studies of the relationship between material structure and processes (particularly the effect of hydrogen dilution) are reported here. 32 refs., 28 figs., 9 tabs.

  19. A two-port polarization-insensitive coupler module between single-mode fiber and silicon-wire waveguide

    E-Print Network [OSTI]

    Shiraishi, Kazuo; Yoda, Hidehiko; Tsai, Chen S

    2012-01-01T23:59:59.000Z

    and C. Tsai, “A two-port single- mode fiber– silicon wireA two-port polarization-insensitive coupler module betweenAbstract: A two-port polarization-insensitive single-mode

  20. Method for harvesting rare earth barium copper oxide single crystals

    DOE Patents [OSTI]

    Todt, V.R.; Sengupta, S.; Shi, D.

    1996-04-02T23:59:59.000Z

    A method of preparing high temperature superconductor single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid. 2 figs.

  1. Ultrafast dynamics of excitons in tetracene single crystals

    SciTech Connect (OSTI)

    Birech, Zephania; Schwoerer, Heinrich, E-mail: heso@sun.ac.za [Laser Research Institute, Stellenbosch University, Stellenbosch 7600 (South Africa)] [Laser Research Institute, Stellenbosch University, Stellenbosch 7600 (South Africa); Schwoerer, Markus [Department of Physics, University of Bayreuth, Bayreuth (Germany)] [Department of Physics, University of Bayreuth, Bayreuth (Germany); Schmeiler, Teresa; Pflaum, Jens [Experimental Physics VI, University of Würzburg and Bavarian Center for Applied Energy Research, Würzburg (Germany)] [Experimental Physics VI, University of Würzburg and Bavarian Center for Applied Energy Research, Würzburg (Germany)

    2014-03-21T23:59:59.000Z

    Ultrafast exciton dynamics in free standing 200 nm thin tetracene single crystals were studied at room temperature by femtosecond transient absorption spectroscopy in the visible spectral range. The complex spectrally overlapping transient absorption traces of single crystals were systematically deconvoluted. From this, the ultrafast dynamics of the ground, excited, and transition states were identified including singlet exciton fission into two triplet excitons. Fission is generated through both, direct fission of higher singlet states S{sub n} on a sub-picosecond timescale, and thermally activated fission of the singlet exciton S{sub 1} on a 40 ps timescale. The high energy Davydov component of the S{sub 1} exciton is proposed to undergo fission on a sub-picoseconds timescale. At high density of triplet excitons their mutual annihilation (triplet-triplet annihilation) occurs on a <10 ps timescale.

  2. Growth and characterization of lithium yttrium borate single crystals

    SciTech Connect (OSTI)

    Singh, A. K.; Singh, S. G.; Tyagi, M.; Desai, D. G.; Sen, Shashwati [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai- 400085 (India)

    2014-04-24T23:59:59.000Z

    Single crystals of 0.1% Ce doped Li{sub 6}Y(BO{sub 3}){sub 3} have been grown using the Czochralski technique. The photoluminescence study of these crystals shows a broad emission at ? 420 nm corresponding to Ce{sub 3+} emission from 5d?4f energy levels. The decay profile of this emission shows a fast response of ? 28 ns which is highly desirable for detector applications.

  3. Electrical production testing of the D0 Silicon microstrip tracker detector modules

    SciTech Connect (OSTI)

    D0, SMT Production Testing Group; /Fermilab

    2006-03-01T23:59:59.000Z

    The D0 Silicon Microstrip Tracker (SMT) is the innermost system of the D0 detector in Run 2. It consists of 912 detector units, corresponding to 5 different types of assemblies, which add up to a system with 792,576 readout channels. The task entrusted to the Production Testing group was to thoroughly debug, test and grade each detector module before its installation in the tracker. This note describes the production testing sequence and the procedures by which the detector modules were electrically tested and characterized at the various stages of their assembly.

  4. Antenna-coupled silicon-organic hybrid integrated photonic crystal modulator for broadband electromagnetic wave detection

    E-Print Network [OSTI]

    Zhang, Xingyu; Subbaraman, Harish; Wang, Shiyi; Zhan, Qiwen; Luo, Jingdong; Jen, Alex K -Y; Chung, Chi-jui; Yan, Hai; Pan, Zeyu; Nelson, Robert L; Lee, Charles Y -C; Chen, Ray T

    2015-01-01T23:59:59.000Z

    In this work, we design, fabricate and characterize a compact, broadband and highly sensitive integrated photonic electromagnetic field sensor based on a silicon-organic hybrid modulator driven by a bowtie antenna. The large electro-optic (EO) coefficient of organic polymer, the slow-light effects in the silicon slot photonic crystal waveguide (PCW), and the broadband field enhancement provided by the bowtie antenna, are all combined to enhance the interaction of microwaves and optical waves, enabling a high EO modulation efficiency and thus a high sensitivity. The modulator is experimentally demonstrated with a record-high effective in-device EO modulation efficiency of r33=1230pm/V. Modulation response up to 40GHz is measured, with a 3-dB bandwidth of 11GHz. The slot PCW has an interaction length of 300um, and the bowtie antenna has an area smaller than 1cm2. The bowtie antenna in the device is experimentally demonstrated to have a broadband characteristics with a central resonance frequency of 10GHz, as we...

  5. 17th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Workshop Proceedings

    SciTech Connect (OSTI)

    Sopori, B. L.

    2007-08-01T23:59:59.000Z

    The National Center for Photovoltaics sponsored the 17th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, held in Vail, CO, August 5-8, 2007. This meeting provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The theme of this year's meeting was 'Expanding Technology for a Future Powered by Si Photovoltaics.'

  6. Large pyramid shaped single crystals of BiFeO{sub 3} by solvothermal synthesis method

    SciTech Connect (OSTI)

    Sornadurai, D.; Ravindran, T. R.; Paul, V. Thomas; Sastry, V. Sankara [Condensed Matter Physics Division, Materials Science Group, Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Condensed Matter Physics Division, Materials Science Group (India)

    2012-06-05T23:59:59.000Z

    Synthesis parameters are optimized in order to grow single crystals of multiferroic BiFeO{sub 3}. 2 to 3 mm size pyramid (tetrahedron) shaped single crystals were successfully obtained by solvothermal method. Scanning electron microscopy with EDAX confirmed the phase formation. Raman scattering spectra of bulk BiFeO3 single crystals have been measured which match well with reported spectra.

  7. Miniaturized Low-power Electro-optic Modulator Based on Silicon Integrated Nanophotonics and Organic Polymers

    E-Print Network [OSTI]

    Zhang, Xingyu; Luo, Jingdong; Jen, Alex K -Y; Chen, Ray T

    2014-01-01T23:59:59.000Z

    We design and demonstrate a compact, low-power, low-dispersion and broadband optical modulator based on electro-optic (EO) polymer refilled silicon slot photonic crystal waveguide (PCW). The EO polymer is engineered for large EO activity and near-infrared transparency. The half-wave switching-voltage is measured to be V{\\pi}=0.97V over optical spectrum range of 8nm, corresponding to a record-high effective in-device r33 of 1190pm/V and V{\\pi} L of 0.291Vmm in a push-pull configuration. Excluding the slow-light effect, we estimate the EO polymer is poled with an ultra-high efficiency of 89pm/V in the slot. In addition, to achieve high-speed modulation, silicon PCW is selectively doped to reduce RC time delay. The 3-dB RF bandwidth of the modulator is measured to be 11GHz, and a modulation response up to 40GHz is observed.

  8. Effective electro-optical modulation with high extinction ratio by a graphene-silicon microring resonator

    E-Print Network [OSTI]

    Ding, Yunhong; Xiao, Sanshui; Hu, Hao; Frandsen, Lars Hagedorn; Mortensen, N Asger; Yvind, Kresten

    2015-01-01T23:59:59.000Z

    Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultra-large absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through tuning of Fermi level enables electro-optical modulation, optical-optical switching, and other optoelectronics applications. However, achieving a high modulation depth remains a challenge because of the modest graphene-light interaction in the graphene-silicon devices, typically, utilizing only a monolayer or few layers of graphene. Here, we comprehensively study the interaction between graphene and a microring resonator, and its influence on the optical modulation depth. We demonstrate graphene-silicon microring devices showing a high modulation depth of 12.5 dB with a relatively low bias voltage of 8.8 V. On-off electro-optical switching with an extinction ratio of 3.8 dB is successfully demonstrated by applying a square-waveform with a 4 V peak-to-peak voltage.

  9. Acquisition of Single Crystal Growth and Characterization Equipment

    SciTech Connect (OSTI)

    Maple, M. Brian; Zocco, Diego A.

    2008-12-09T23:59:59.000Z

    Final Report for DOE Grant No. DE-FG02-04ER46178 'Acquisition of Single Crystal Growth and Characterization Equipment'. There is growing concern in the condensed matter community that the need for quality crystal growth and materials preparation laboratories is not being met in the United States. It has been suggested that there are too many researchers performing measurements on too few materials. As a result, many user facilities are not being used optimally. The number of proficient crystal growers is too small. In addition, insufficient attention is being paid to the enterprise of finding new and interesting materials, which is the driving force behind much of condensed matter research and, ultimately, technology. While a detailed assessment of this situation is clearly needed, enough evidence of a problem already exists to compel a general consensus that the situation must be addressed promptly. This final report describes the work carried out during the last four years in our group, in which a state-of-the-art single crystal growth and characterization facility was established for the study of novel oxides and intermetallic compounds of rare earth, actinide and transition metal elements. Research emphasis is on the physics of superconducting (SC), magnetic, heavy fermion (HF), non-Fermi liquid (NFL) and other types of strongly correlated electron phenomena in bulk single crystals. Properties of these materials are being studied as a function of concentration of chemical constituents, temperature, pressure, and magnetic field, which provide information about the electronic, lattice, and magnetic excitations at the root of various strongly correlated electron phenomena. Most importantly, the facility makes possible the investigation of material properties that can only be achieved in high quality bulk single crystals, including magnetic and transport phenomena, studies of the effects of disorder, properties in the clean limit, and spectroscopic and scattering studies through efforts with numerous collaborators. These endeavors will assist the effort to explain various outstanding theoretical problems, such as order parameter symmetries and electron-pairing mechanisms in unconventional superconductors, the relationship between superconductivity and magnetic order in certain correlated electron systems, the role of disorder in non-Fermi liquid behavior and unconventional superconductivity, and the nature of interactions between localized and itinerant electrons in these materials. Understanding the mechanisms behind strongly correlated electron behavior has important technological implications.

  10. Lithium niobate single-crystal and photo-functional device

    DOE Patents [OSTI]

    Gopalan, Venkatraman (State College, PA); Mitchell, Terrence E. (Los Alamos, NM); Kitamura, Kenji (Tsukuba, JP); Furukawa, Yasunori (Tsukuba, JP)

    2001-01-01T23:59:59.000Z

    Provided are lithium niobate single-crystal that requires a low voltage of not larger than 10 kV/nm for its ferroelectric polarization inversion and of which the polarization can be periodically inverted with accuracy even at such a low voltage, and a photo-functional device comprising the crystal. The crystal has a molar fraction of Li.sub.2 O/(Nb.sub.2 O.sub.5 +Li.sub.2 O) of falling between 0.49 and 0.52. The photo-functional device can convert a laser ray being incident thereon.

  11. Method for thermal processing alumina-enriched spinel single crystals

    DOE Patents [OSTI]

    Jantzen, Carol M. (Aiken, SC)

    1995-01-01T23:59:59.000Z

    A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly.

  12. Method for thermal processing alumina-enriched spinel single crystals

    DOE Patents [OSTI]

    Jantzen, C.M.

    1995-05-09T23:59:59.000Z

    A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly. 12 figs.

  13. Superconductivity in SrNi2P2 single crystals

    SciTech Connect (OSTI)

    Ronning, Filip [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Park, Tuscon [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    Heat capacity, magnetic susceptibility, and resistivity of SrNi{sub 2}P{sub 2} single crystals are presented, illustrating the structural transition at 325 K, and bulk superconductivity at 1.4 K. The magnitude of {Tc}, fits to the heat capacity data, the small upper critical field H{sub c2} = 390 Oe, and {kappa} = 2.1 suggests a conventional fully gapped superconductor. With applied pressure we find that superconductivity persists into the so-called 'collapsed tetragonal' phase, although the transition temperature is monotonically suppressed with increasing pressure. This argues that reduced dimensionality can be a mechanism for increasing the transition temperatures of layered NiP, as well as layered FeAs and NiAs, superconductors.

  14. Shock compression experiments on Lithium Deuteride single crystals.

    SciTech Connect (OSTI)

    Knudson, Marcus D.; Desjarlais, Michael P.; Lemke, Raymond W.

    2014-10-01T23:59:59.000Z

    S hock compression exper iments in the few hundred GPa (multi - Mabr) regime were performed on Lithium Deuteride (LiD) single crystals . This study utilized the high velocity flyer plate capability of the Sandia Z Machine to perform impact experiments at flyer plate velocities in the range of 17 - 32 km/s. Measurements included pressure, density, and temperature between ~200 - 600 GPa along the Principal Hugoniot - the locus of end states achievable through compression by large amplitude shock waves - as well as pressure and density of re - shock states up to ~900 GPa . The experimental measurements are compared with recent density functional theory calculations as well as a new tabular equation of state developed at Los Alamos National Labs.

  15. Performance of Large grain and Single Crystal Niobium Cavities

    SciTech Connect (OSTI)

    Kneisel, Peter; Ciovati, Gianluigi; Sekutowicz, Jacek

    2006-07-01T23:59:59.000Z

    We have fabricated and tested several single and one multi-cell cavity made from large grain niobium of four different ingots. Two cavities at a frequency of ~ 2.2 GHz were made from single crystal sheets. Large grain material was used for four single cell cavities of the HG â and OC shapes, a 7-cell cavity of the HG â shape â all resonating at 1500 MHz â and an ILC_LL single cell cavity at 1300 MHz. We began to explore also different chemical polishing baths such as a 1:1:1 and a 1:1:2 buffered solution and explored the change of cavity performance as a function of material removal. The results from these preliminary investigations are reported in this contribution.

  16. Single crystal metal wedges for surface acoustic wave propagation

    DOE Patents [OSTI]

    Fisher, E.S.

    1980-05-09T23:59:59.000Z

    An ultrasonic testing device has been developed to evaluate flaws and inhomogeneities in the near-surface region of a test material. A metal single crystal wedge is used to generate high frequency Rayleigh surface waves in the test material surface by conversion of a slow velocity, bulk acoustic mode in the wedge into a Rayleigh wave at the metal-wedge test material interface. Particular classes of metals have been found to provide the bulk acoustic modes necessary for production of a surface wave with extremely high frequency and angular collimation. The high frequency allows flaws and inhomogeneities to be examined with greater resolution. The high degree of angular collimation for the outgoing ultrasonic beam permits precision angular location of flaws and inhomogeneities in the test material surface.

  17. Single crystal metal wedges for surface acoustic wave propagation

    DOE Patents [OSTI]

    Fisher, Edward S. (Wheaton, IL)

    1982-01-01T23:59:59.000Z

    An ultrasonic testing device has been developed to evaluate flaws and inhomogeneities in the near-surface region of a test material. A metal single crystal wedge is used to generate high frequency Rayleigh surface waves in the test material surface by conversion of a slow velocity, bulk acoustic mode in the wedge into a Rayleigh wave at the metal-wedge test material interface. Particular classes of metals have been found to provide the bulk acoustic modes necessary for production of a surface wave with extremely high frequency and angular collimation. The high frequency allows flaws and inhomogeneities to be examined with greater resolution. The high degree of angular collimation for the outgoing ultrasonic beam permits precision angular location of flaws and inhomogeneities in the test material surface.

  18. Studying the magnetic properties of CoSi single crystals

    SciTech Connect (OSTI)

    Narozhnyi, V. N., E-mail: narozhnyivn@gmail.com; Krasnorussky, V. N. [Russian Academy of Sciences, Vereshchagin Institute for High Pressure Physics (Russian Federation)

    2013-05-15T23:59:59.000Z

    The magnetic properties of CoSi single crystals have been measured in a range of temperatures T = 5.5-450 K and magnetic field strengths H {<=} 11 kOe. A comparison of the results for crystals grown in various laboratories allowed the temperature dependence of magnetic susceptibility {chi}(T) = M(T)/H to be determined for a hypothetical 'ideal' (free of magnetic impurities and defects) CoSi crystal. The susceptibility of this ideal crystal in the entire temperature range exhibits a diamagnetic character. The {chi}(T) value significantly increases in absolute value with decreasing temperature and exhibits saturation at the lowest temperatures studied. For real CoSi crystals of four types, paramagnetic contributions to the susceptibility have been evaluated and nonlinear (with respect to the field) contributions to the magnetization have been separated and taken into account in the calculations of {chi}(T).

  19. Ductility and chemical reactions at the interface between nickel and magnesium oxide single crystals.

    E-Print Network [OSTI]

    Hasselman, Didericus Petrus Hermannus

    2011-01-01T23:59:59.000Z

    ??An investigation was conducted on the interaction between nickel metal and single crystals of magnesium oxide. The nickel was cleaned with purified hydrogen gas at… (more)

  20. E-Print Network 3.0 - acid single crystals Sample Search Results

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

    of Chemistry single crystal X-ray diffraction. Consequently, the crystal structure... and methanol, followed by slow evaporation at room temperature ... Source: de Gispert, Adri...

  1. E-Print Network 3.0 - advanced single crystal Sample Search Results

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

    Engineering ; Materials Science 34 ENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR LINAC Summary: ENHANCEMENT OF THE POSITRON...

  2. Method of forming buried oxide layers in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir City, TN)

    2000-01-01T23:59:59.000Z

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  3. SINGLE-CRYSTAL SAPPHIRE OPTICAL FIBER SENSOR INSTRUMENTATION

    SciTech Connect (OSTI)

    A. Wang; G. Pickrell; R. May

    2002-09-10T23:59:59.000Z

    Accurate measurement of temperature is essential for the safe and efficient operation and control of a wide range of industrial processes. Appropriate techniques and instrumentation are needed depending on the temperature measurement requirements in different industrial processes and working environments. Harsh environments are common in many industrial applications. These harsh environments may involve extreme physical conditions, such as high-temperature, high-pressure, corrosive agents, toxicity, strong electromagnetic interference, and high-energy radiation exposure. Due to these severe environmental conditions, conventional temperature sensors are often difficult to apply. This situation has opened a new but challenging opportunity for the sensor society to provide robust, high-performance, and cost-effective temperature sensors capable of operating in those harsh environments. The focus of this research program has been to develop a temperature measurement system for temperature measurements in the primary and secondary stages of slagging gasifiers. For this application the temperature measurement system must be able to withstand the extremely harsh environment posed by the high temperatures and corrosive agents present in these systems. Real-time, accurate and reliable monitoring of temperature for the coal gasification process is important to realize the full economic potential of these gasification systems. Long life and stability of operation in the high temperature environment is essential for the temperature measurement system to ensure the continuous running of the coal gasification system over the long term. In this high temperature and chemically corrosive environment, rather limited high temperature measurement techniques such as high temperature thermocouples and optical/acoustic pyrometers are available, each with their own limitations. In this research program, five different temperature sensing schemes based on the single crystal sapphire material were thoroughly investigated to determine an optimal approach for on-line, real-time, reliable, long-term monitoring of temperatures inside the coal gasification environment. Among these were a sapphire fiber extrinsic Fabry-Perot interferometric (EFPI) sensor; an intensity-measurement based polarimetric sapphire sensor and a broadband polarimetric differential interferometric (BPDI) sapphire sensor. Based on the current evaluation and analysis of the experimental results, the broadband polarimetric differential interferometric (BPDI) sensor system was chosen for further prototype instrumentation development because of it's superior performance compared to the other systems. This approach is based on the self-calibrating measurement of the optical path length differences in a single-crystal sapphire disk, which is a function of both the temperature dependent birefringence and the temperature dependent dimensional changes.

  4. SINGLE-CRYSTAL SAPPHIRE OPTICAL FIBER SENSOR INSTRUMENTATION

    SciTech Connect (OSTI)

    A. Wang; G. Pickrell; R. May

    2002-10-18T23:59:59.000Z

    Accurate measurement of temperature is essential for the safe and efficient operation and control of a wide range of industrial processes. Appropriate techniques and instrumentation are needed depending on the temperature measurement requirements in different industrial processes and working environments. Harsh environments are common in many industrial applications. These harsh environments may involve extreme physical conditions, such as high-temperature, high-pressure, corrosive agents, toxicity, strong electromagnetic interference, and high-energy radiation exposure. Due to these severe environmental conditions, conventional temperature sensors are often difficult to apply. This situation has opened a new but challenging opportunity for the sensor society to provide robust, high-performance, and cost-effective temperature sensors capable of operating in those harsh environments. The focus of this research program has been to develop a temperature measurement system for temperature measurements in the primary and secondary stages of slagging gasifiers. For this application the temperature measurement system must be able to withstand the extremely harsh environment posed by the high temperatures and corrosive agents present in these systems. Real-time, accurate and reliable monitoring of temperature for the coal gasification process is important to realize the full economic potential of these gasification systems. Long life and stability of operation in the high temperature environment is essential for the temperature measurement system to ensure the continuous running of the coal gasification system over the long term. In this high temperature and chemically corrosive environment, rather limited high temperature measurement techniques such as high temperature thermocouples and optical/acoustic pyrometers are available, each with their own limitations. In this research program, five different temperature sensing schemes based on the single crystal sapphire material were thoroughly investigated to determine an optimal approach for on-line, real-time, reliable, long-term monitoring of temperatures inside the coal gasification environment. Among these were a sapphire fiber extrinsic Fabry-Perot interferometric (EFPI) sensor; an intensity-measurement based polarimetric sapphire sensor and a broadband polarimetric differential interferometric (BPDI) sapphire sensor. Based on the current evaluation and analysis of the experimental results, the BPDI sensor system was chosen for further prototype instrumentation development because of it's superior performance compared to the other systems. This approach is based on the self-calibrating measurement of the optical path length differences in a single-crystal sapphire disk, which is a function of both the temperature dependent birefringence and the temperature dependent dimensional changes.

  5. Growth and electrochromic properties of single-crystal V2O5 nanorod arrays

    E-Print Network [OSTI]

    Cao, Guozhong

    Growth and electrochromic properties of single-crystal V2O5 nanorod arrays Katsunori Takahashi reports a study on the template-based growth and electrochromic properties of single-crystal vanadium demonstrated significantly enhanced electrochromic properties; both the larger change of transmittance

  6. Microhardness of Czochralski-grown single crystals of VB{sub 2}

    SciTech Connect (OSTI)

    Bulfon, C.; Sassik, H. [Institut fuer Experimentalphysik, Wien (Austria)] [Institut fuer Experimentalphysik, Wien (Austria); Leithe-Jasper, A.; Rogl, P. [Universitaet Wien (Austria)] [Universitaet Wien (Austria)

    1997-10-01T23:59:59.000Z

    Single crystals of congruent melting hexagonal VB{sub 2} were grown used a triarc furnace applying the Czochralski technique. Orientation dependent microhardness measurements on a single crystal reveal quasi similar hardness in the crystallographic directions <00.1> and <10.0>, whereas the <10.1> shows slightly lower values.

  7. Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films on sapphire

    E-Print Network [OSTI]

    Boyer, Edmond

    Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films Cedex 9, France (Dated: 15 March 2011) Uniform single layer graphene was grown on single-crystal Ir. These graphene layers have a single crystallographic orientation and a very low density of defects, as shown

  8. Oxygen diffusion in titanite: Lattice diffusion and fast-path diffusion in single crystals

    E-Print Network [OSTI]

    Watson, E. Bruce

    Oxygen diffusion in titanite: Lattice diffusion and fast-path diffusion in single crystals X June 2006 Editor: P. Deines Abstract Oxygen diffusion in natural and synthetic single-crystal titanite was characterized under both dry and water-present conditions. For the dry experiments, pre-polished titanite

  9. DEVELOPMENT OF PROTECTIVE COATINGS FOR SINGLE CRYSTAL TURBINE BLADES

    SciTech Connect (OSTI)

    Amarendra K. Rai

    2006-12-04T23:59:59.000Z

    Turbine blades in coal derived syngas systems are subject to oxidation and corrosion due to high steam temperature and pressure. Thermal barrier coatings (TBCs) are developed to address these problems. The emphasis is on prime-reliant design and a better coating architecture, having high temperature and corrosion resistance properties for turbine blades. In Phase I, UES Inc. proposed to develop, characterize and optimize a prime reliant TBC system, having smooth and defect-free NiCoCrAlY bond layer and a defect free oxide sublayer, using a filtered arc technology. Phase I work demonstrated the deposition of highly dense, smooth and defect free NiCoCrAlY bond coat on a single crystal CMSX-4 substrate and the deposition of alpha-alumina and yttrium aluminum garnet (YAG) sublayer on top of the bond coat. Isothermal and cyclic oxidation test and pre- and post-characterization of these layers, in Phase I work, (with and without top TBC layer of commercial EB PVD YSZ) revealed significant performance enhancement.

  10. Radiation tolerance of piezoelectric bulk single-crystal aluminum nitride

    SciTech Connect (OSTI)

    David A. Parks; Bernhard R. Tittmann

    2014-07-01T23:59:59.000Z

    For practical use in harsh radiation environments, we pose selection criteria for piezoelectric materials for nondestructive evaluation (NDE) and material characterization. Using these criteria, piezoelectric aluminum nitride is shown to be an excellent candidate. The results of tests on an aluminumnitride-based transducer operating in a nuclear reactor are also presented. We demonstrate the tolerance of single-crystal piezoelectric aluminum nitride after fast and thermal neutron fluences of 1.85 × 1018 neutron/cm2 and 5.8 × 1018 neutron/cm2, respectively, and a gamma dose of 26.8 MGy. The radiation hardness of AlN is most evident from the unaltered piezoelectric coefficient d33, which measured 5.5 pC/N after a fast and thermal neutron exposure in a nuclear reactor core for over 120 MWh, in agreement with the published literature value. The results offer potential for improving reactor safety and furthering the understanding of radiation effects on materials by enabling structural health monitoring and NDE in spite of the high levels of radiation and high temperatures, which are known to destroy typical commercial ultrasonic transducers.

  11. Growth and properties of Lithium Salicylate single crystals

    SciTech Connect (OSTI)

    Zaitseva, N; Newby, J; Hull, G; Saw, C; Carman, L; Cherepy, N; Payne, S

    2009-02-13T23:59:59.000Z

    An attractive feature of {sup 6}Li containing fluorescence materials that determines their potential application in radiation detection is the capture reaction with slow ({approx}< 100 keV) neutrons: {sup 6}Li + n = {sup 4}He + {sup 3}H + 4.8MeV. The use of {sup 6}Li-salicylate (LiSal, LiC{sub 6}H{sub 5}O{sub 3}) for thermal neutron detection was previously studied in liquid and polycrystalline scintillators. The studies showed that both liquid and polycrystalline LiSal scintillators could be utilized in pulse shape discrimination (PSD) techniques that enable separation of neutrons from the background gamma radiation. However, it was found that the efficiency of neutron detection using LiSal in liquid solutions was severely limited by its low solubility in commonly used organic solvents like, for example, toluene or xylene. Better results were obtained with neutron detectors containing the compound in its crystalline form, such as pressed pellets, or microscopic-scale (7-14 micron) crystals dispersed in various media. The expectation drown from these studies was that further improvement of pulse height, PSD, and efficiency characteristics could be reached with larger and more transparent LiSal crystals, growth of which has not been reported so far. In this paper, we present the first results on growth and characterization of relatively large, a cm-scale size, single crystals of LiSal with good optical quality. The crystals were grown both from aqueous and anhydrous (methanol) media, mainly for neutron detection studies. However, the results on growth and structural characterization may be interesting for other fields where LiSal, together with other alkali metal salicylates, is used for biological, medical, and chemical (as catalyst) applications.

  12. Thermopower, electrical and Hall conductivity of undoped and doped iron disilicide single crystals

    SciTech Connect (OSTI)

    Heinrich, A.; Behr, G.; Griessmann, H.; Teichert, S.; Lange, H.

    1997-07-01T23:59:59.000Z

    The electrical transport properties of {beta}-FeSi{sub 2} single crystals have been investigated in dependence on the purity of the source material and on doping with 3d transition metals. The transport properties included are electrical conductivity, Hall conductivity and thermopower mainly in the temperature range from 4K to 300K. The single crystals have been prepared by chemical transport reaction in a closed system with iodine as transport agent. In undoped single crystals prepared with 5N Fe both electrical conductivity and thermopower depend on the composition within the homogeneity range of {beta}-FeSi{sub 2} which is explained by different intrinsic defects at the Si-rich and Fe-rich phase boundaries. In both undoped and doped single crystals impurity band conduction is observed at low temperatures but above 100K extrinsic behavior determined by shallow impurity states. The thermopower shows between 100K and 200K a significant phonon drag contribution which depends on intrinsic defects and additional doping. The Hall resistivity is considered mainly with respect to an anomalous contribution found in p-type and n-type single crystals and thin films. In addition doped single crystals show at temperatures below about 130K an hysteresis of the Hall voltage. These results make former mobility data uncertain. Comparison will be made between the transport properties of single crystals and polycrystalline material.

  13. Broadband energy-efficient optical modulation by hybrid integration of silicon nanophotonics and organic electro-optic polymer

    E-Print Network [OSTI]

    Zhang, Xingyu; Subbaraman, Harish; Luo, Jingdong; Jen, Alex K -Y; Chung, Chi-jui; Yan, Hai; Pan, Zeyu; Nelson, Robert L; Chen, Ray T

    2015-01-01T23:59:59.000Z

    Silicon-organic hybrid integrated devices have emerging applications ranging from high-speed optical interconnects to photonic electromagnetic-field sensors. Silicon slot photonic crystal waveguides (PCWs) filled with electro-optic (EO) polymers combine the slow-light effect in PCWs with the high polarizability of EO polymers, which promises the realization of high-performance optical modulators. In this paper, a broadband, power-efficient, low-dispersion, and compact optical modulator based on an EO polymer filled silicon slot PCW is presented. A small voltage-length product of V{\\pi}*L=0.282Vmm is achieved, corresponding to an unprecedented record-high effective in-device EO coefficient (r33) of 1230pm/V. Assisted by a backside gate voltage, the modulation response up to 50GHz is observed, with a 3-dB bandwidth of 15GHz, and the estimated energy consumption is 94.4fJ/bit at 10Gbit/s. Furthermore, lattice-shifted PCWs are utilized to enhance the optical bandwidth by a factor of ~10X over other modulators bas...

  14. Theoretical nonlinear response of complex single crystal under multi-axial tensile loading

    E-Print Network [OSTI]

    Misra, Anil; Ching, W. Y.

    2013-03-19T23:59:59.000Z

    The mechanical properties of single crystals are of interest as they represent the behavior of the basic building blocks. Using the density functional theory based ab initio technique we have devised an approach to analyze the behavior of single...

  15. Carrier Dynamics in a-Fe2O3 (0001) Thin Films and Single Crystals...

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

    Carrier Dynamics in a-Fe2O3 (0001) Thin Films and Single Crystals Probed by Femtosecond Transient Absorption and Reflectivity. Carrier Dynamics in a-Fe2O3 (0001) Thin Films and...

  16. Modeling the elastic and plastic response of single crystals and polycrystalline aggregates

    E-Print Network [OSTI]

    Patwardhan, Parag Vilas

    2005-02-17T23:59:59.000Z

    MODELING THE ELASTIC AND PLASTIC RESPONSE OF SINGLE CRYSTALS AND POLYCRYSTALLINE AGGREGATES A Thesis by PARAG VILAS PATWARDHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 2003 Major Subject: Mechanical Engineering MODELING THE ELASTIC AND PLASTIC RESPONSE OF SINGLE CRYSTALS AND POLYCRYSTALLINE AGGREGATES A Thesis by PARAG VILAS...

  17. Single crystal growth and characterization of ilmenite, FeTiO?, for electronic applications

    E-Print Network [OSTI]

    Gries, Brian Leonard

    2012-06-07T23:59:59.000Z

    SINGLE CRYSTAL GROWTH AND CHARACTERIZATION OF ILMENITE, FeTi03, FOR ELECTRONIC APPUCATIONS A Thesis by BRIAN LEONARD GRIES Submitted to the Office of Graduate Studies Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December 1988 Major Subject: Electrical Engineering SINGLE CRYSTAL GROWTH AND CHARACTERIZATION OF ILMENITE, FeT)Oq, FOR ELECTRONIC APPLICATIONS A Thesis by BRIAN LEONARD GRIES Approved as to style and content by...

  18. Testing and Analysis for Lifetime Prediction of Crystalline Silicon PV Modules Undergoing Degradation by System Voltage Stress: Preprint

    SciTech Connect (OSTI)

    Hacke, P.; Smith, R.; Terwiliger, K.; Glick, S.; Jordan, D.; Johnston, S.; Kempe, M.; Kurtz, S.

    2012-07-01T23:59:59.000Z

    Acceleration factors are calculated for crystalline silicon PV modules under system voltage stress by comparing the module power during degradation outdoors to that in accelerated testing at three temperatures and 85% relative humidity. A lognormal analysis is applied to the accelerated lifetime test data considering failure at 80% of the initial module power. Activation energy of 0.73 eV for the rate of failure is determined, and the probability of module failure at an arbitrary temperature is predicted. To obtain statistical data for multiple modules over the course of degradation in-situ of the test chamber, dark I-V measurements are obtained and transformed using superposition, which is found well suited for rapid and quantitative evaluation of potential-induced degradation. It is determined that shunt resistance measurements alone do not represent the extent of power degradation. This is explained with a two-diode model analysis that shows an increasing second diode recombination current and ideality factor as the degradation in module power progresses. Failure modes of the modules stressed outdoors are examined and compared to those stressed in accelerated tests.

  19. Mechanical Dissipation in Silicon Flexures

    E-Print Network [OSTI]

    S. Reid; G. Cagnoli; D. R. M. Crooks; J. Hough; P. Murray; S. Rowan; M. M. Fejer; R. Route; S. Zappe

    2005-10-28T23:59:59.000Z

    The thermo-mechanical properties of silicon make it of significant interest as a possible material for mirror substrates and suspension elements for future long-baseline gravitational wave detectors. The mechanical dissipation in 92um thick single-crystal silicon cantilevers has been observed over the temperature range 85 K to 300 K, with dissipation approaching levels down to phi = 4.4E-7.

  20. Stretchable form of single crystal silicon for high performance electronics on rubber substrates

    DOE Patents [OSTI]

    Rogers, John A. (Champaign, IL); Khang, Dahl-Young (Seoul, KR); Sun, Yugang (Naperville, IL); Menard, Etienne (Durham, NC)

    2012-06-12T23:59:59.000Z

    The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

  1. Stretchable form of single crystal silicon for high performance electronics on rubber substrates

    DOE Patents [OSTI]

    University of Illinois (Urbana, IL)

    2009-04-21T23:59:59.000Z

    The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

  2. EXPERIMENTAL VERIFICATION OF INTERNAL FRICTION AT GHZ FREQUENCIES IN DOPED SINGLE-CRYSTAL SILICON

    E-Print Network [OSTI]

    Afshari, Ehsan

    losses into account. Recent work in MEMS resonators has started to utilize some of the electrical of the energy loss in a resonator, also has similar limits that arise from practical implementation, including Eugene Hwang and Sunil A. Bhave OxideMEMS Lab, School of Electrical and Computer Engineering, Cornell

  3. Polymorphic single crystal {r_reversible} single crystal transition in K{sub 0.975}Rb{sub 0.025}NO{sub 3}

    SciTech Connect (OSTI)

    Asadov, Yu. G., E-mail: yusifasadov@rambler.ru; Nasirov, E. V. [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan)

    2010-09-15T23:59:59.000Z

    Polymorphic transformations in K{sub 0.975}Rb{sub 0.025}NO{sub 3} single crystals have been investigated by optical microscopy and X-ray diffraction. The equilibrium temperature between modifications II and III has been determined. It is established that the crystal growth at II {r_reversible} III polymorphic transitions is accompanied by the formation and growth of daughter-modification nuclei in the matrix crystal.

  4. Cast polycrystalline silicon photovoltaic module manufacturing technology improvements. Semiannual subcontract report, 8 December 1993--30 June 1994

    SciTech Connect (OSTI)

    Wohlgemuth, J. [Solarex Corp., Frederick, MD (United States)

    1995-03-01T23:59:59.000Z

    This report describes work done under a 3-year program to advance Solarex`s cast polycrystalline silicon manufacturing technology, reduce module production cost, increase module performance, and expand Solarex`s commercial production capacities. The accomplishments described in this report are as follows: (1) the authors designed modifications to casting stations, ceramic molds, and sizing saws to allow for casting and sizing of larger ingots; (2) they demonstrated the casting of ingots with 17% larger volume; (3) the selected and purchased a new wire saw from HCT Shaping Systems; (4) they demonstrated wafering of eight bricks (2,400 wafers or {approximately}4.4 kilowatts at the cell level) in a 6.5-h run; (5) they demonstrated 14% average cell efficiency in the laboratory using an aluminum paste back surface field; (6) the Automation and Robotics Research Institute (ARRI) completed a modeling study of the Solarex module assembly process; (7) they identified and qualified three new lower-cost back sheet materials through accelerated environmental tests; and (8) they designed and built a test structure for mounting frameless modules, and selected two adhesives and began testing their ability to hold modules to the structure.

  5. Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

    DOE Patents [OSTI]

    Charache, G.W.; Baldasaro, P.F.; Nichols, G.J.

    1998-06-23T23:59:59.000Z

    A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type or an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers. 12 figs.

  6. Research on stable, high-efficiency amorphous silicon multijunction modules. Annual subcontract report, 1 November 1992--31 May 1993

    SciTech Connect (OSTI)

    Ghosh, M.; Kampas, F.; Xi, J. [Advanced Photovoltaic Systems, Inc., Princeton, NJ (United States)

    1993-09-01T23:59:59.000Z

    This report describes progress made in the first half of Phase II of a three-phase program to develop high-efficiency, same-band-gap, amorphous-silicon, tandem-junction modules. Results for both 1-cm- {sup 2} devices and 0.3-m (0.09-m{sup 2}) modules are given. considerable effort was devoted to finding a device structure and layer conditions that reconcile the conflicting requirements of a good ``tunnel junction`` contact between the two stacks and a high-efficiency device. High-band-gap p{sub 2}layers, which enable good voltage and current from the second stack, were found to result in poor tunnel junctions. The best results were obtained by using a thin (1-nm-thick) p{sup +} layer (no carbon) between the n{sub 1} and p{sub 2} layers of the device.

  7. 18th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Workshop Proceedings, 3-6 August 2008, Vail, Colorado

    SciTech Connect (OSTI)

    Sopori, B. L.

    2008-09-01T23:59:59.000Z

    The National Center for Photovoltaics sponsored the 18th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, held in Vail, CO, August 3-6, 2008. This meeting provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The theme of this year's meeting was 'New Directions for Rapidly Growing Silicon Technologies.'

  8. 15th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Extended Abstracts and Papers

    SciTech Connect (OSTI)

    Sopori, B. L.

    2005-11-01T23:59:59.000Z

    The National Center for Photovoltaics sponsored the 15th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, held in Vail, CO, August 7-10, 2005. This meeting provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The workshop addressed the fundamental properties of PV silicon, new solar cell designs, and advanced solar cell processing techniques. A combination of oral presentations by invited speakers, poster sessions, and discussion sessions reviewed recent advances in crystal growth, new cell designs, new processes and process characterization techniques, and cell fabrication approaches suitable for future manufacturing demands. The theme of this year's meeting was 'Providing the Scientific Basis for Industrial Success.' Specific sessions during the workshop included: Advances in crystal growth and material issues; Impurities and defects in Si; Advanced processing; High-efficiency Si solar cells; Thin Si solar cells; and Cell design for efficiency and reliability module operation. The topic for the Rump Session was ''Si Feedstock: The Show Stopper'' and featured a panel discussion by representatives from various PV companies.

  9. Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement Regime

    E-Print Network [OSTI]

    Osterloh, Frank

    Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement, catalysis, WO3, tungsten oxide, nanosheet, nanocrystal, quantum confinement, solar energy conversion INTRODUCTION Tungsten trioxide crystallizes in the ReO3 structure type and is an n-type semiconductor with a 2

  10. Transport and superconducting properties of RNi2B2C (R=Y, Lu) single crystals

    E-Print Network [OSTI]

    Rathnayaka, KDD; Bhatnagar, AK; Parasiris, A.; Naugle, Donald G.

    1997-01-01T23:59:59.000Z

    The in-plane resistivity, in-plane absolute thermopower, and upper critical held measurements are reported for single-crystal samples of YNi2B2C and LuNi2B2C superconductors. The in-plane resistivity shows metallic behavior and varies approximately...

  11. E-Print Network 3.0 - acetate single crystals Sample Search Results

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

    Summary: precipitate Total crystals Only crystalb 1 30% MPD Na Acetate pH 4.6 0.02 M CaCl2 5.06 197 540 17 1 2 0.4 M K... a single crystal from 755 samples. Note that had the...

  12. Molecular dynamics simulations of the nano-scale room-temperature oxidation of aluminum single crystals

    E-Print Network [OSTI]

    Southern California, University of

    Molecular dynamics simulations of the nano-scale room-temperature oxidation of aluminum single Abstract The oxidation of aluminum single crystals is studied using molecular dynamics (MD) simulations with dynamic charge transfer between atoms. The simulations are performed on three aluminum low-index surfaces

  13. Fractal Iron Oxide Single-Crystal Dendritic Micro-Pines of Magnetic

    E-Print Network [OSTI]

    Wang, Zhong L.

    Fractal Iron Oxide Single-Crystal Dendritic Micro-Pines of Magnetic a-Fe2O3: Large-Scale Synthesis,2] Fractal structures are common in nature across all length scales, from self-assembled molecules. On the nanoscale, dendritic fractals are one type of hyperbranched structure which are generally formed

  14. Single crystal growth and heteroepitaxy of polyacene thin films on arbitrary substrates

    E-Print Network [OSTI]

    Headrick, Randall L.

    in a number of low-cost, large area electronic applications such as flat panel displays. Organic thin film as other substrates.6-12 Recently, significant progress has been made towards fabricating high quality is to prepare single crystal films on arbitrary substrates. Here we describe two significant advances towards

  15. Active Slip Band Separation and the Energetics of Slip in Single Crystals

    E-Print Network [OSTI]

    Active Slip Band Separation and the Energetics of Slip in Single Crystals Abstract This research supports recent efforts to provide an energetic ap- proach the formulation of new measures of the active slip-band separation and of the number of lattice cells

  16. A LIFETIME PREDICTION MODEL FOR SINGLE CRYSTAL SUPERALLOYS SUBJECTED TO THERMOMECHANICAL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -FATIGUE-OXIDATION DAMAGE A. M. ALAM1 and L. REMY2 1 ALSTOM (Power), Gas Turbine Design Department, Brown Boveri Strasse 7A LIFETIME PREDICTION MODEL FOR SINGLE CRYSTAL SUPERALLOYS SUBJECTED TO THERMOMECHANICAL CREEP 91003, Evry, France ABSTRACT This paper contains a brief description of a lifetime prediction model

  17. Saturation of the Raman amplification by self-phase modulation in silicon nanowaveguides

    E-Print Network [OSTI]

    of short pulses in order to project and optimize the performance of future silicon-based data processing to a regime in which sensitivity to FCA is strongly reduced.7-10 However, depending on the pulse energy-off Raman gain is measured in terms of the pump intensity and shows a clear saturation that is attributed

  18. Development and Evaluation of Test Stations for the Quality Assurance of the Silicon Micro-Strip Detector Modules for the CMS Experiment

    E-Print Network [OSTI]

    Pöttgens, Michael

    2007-01-01T23:59:59.000Z

    CMS (Compact Muon Solenoid) is one of four large-scale detectors which will be operated at the LHC (Large Hadron Collider) at the European Laboratory for Particle Physics (CERN). For the search for new physics the reconstruction of the collision products and their properties is essential. In the innermost part of the CMS detector the traces of ionizing particles are measured utilizing a silicon tracker. A large fraction of this detector is equipped with silicon micro-strip modules which provide a precise space resolution in 1-dimension. A module consists of a sensor for detection of particles, the corresponding read-out electronics (hybrid) and a mechanical support structure. Since the 15,148 modules, which will be installed in the silicon micro-strip detector, have a total sensitive surface area of about 198 m2, the inner tracker of CMS is the largest silicon tracking detector, which has ever been built. While the sensors and hybrids are produced in industry, the construction of the modules and the control o...

  19. 16th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Program, Extended Abstracts, and Papers

    SciTech Connect (OSTI)

    Sopori, B. L.

    2006-08-01T23:59:59.000Z

    The National Center for Photovoltaics sponsored the 16th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes held August 6-9, 2006 in Denver, Colorado. The workshop addressed the fundamental properties of PV-Si, new solar cell designs, and advanced solar cell processing techniques. It provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The Workshop Theme was: "Getting more (Watts) for Less ($i)". A combination of oral presentations by invited speakers, poster sessions, and discussion sessions reviewed recent advances in crystal growth, new cell structures, new processes and process characterization techniques, and cell fabrication approaches suitable for future manufacturing demands. The special sessions included: Feedstock Issues: Si Refining and Purification; Metal-impurity Engineering; Thin Film Si; and Diagnostic Techniques.

  20. Production of ATLAS silicon detector modules Report from the Scandinavian Cluster

    E-Print Network [OSTI]

    Johansen, L G; Solberg, A O; Stugu, B; Oye, O K; Dorholt, O; Huse, T; Stapnes, S; Bingefors, N; Brenner, R; Ehn, S; Ekelöf, T J C; Eklund, L; Lindquist, L E

    2006-01-01T23:59:59.000Z

    This document describes the assembly and quality assurance of Semi Conductor Tracker (SCT) barrel modules performed by the Scandinavian Cluster. The project has been carried out as a joint effort between University of Bergen, University of Oslo and Uppsala University.

  1. Considerations for a Standardized Test for Potential-Induced Degradation of Crystalline Silicon PV Modules (Presentation)

    SciTech Connect (OSTI)

    Hacke, P.

    2012-03-01T23:59:59.000Z

    Over the past decade, there have been observations of module degradation and power loss because of the stress that system voltage bias exerts. This results in part from qualification tests and standards note adequately evaluating for the durability of modules to the long-term effects of high voltage bias that they experience in fielded arrays. This talk deals with factors for consideration, progress, and information still needed for a standardized test for degradation due to system voltage stress.

  2. Nanophotonic production, modulation and switching of ions by silicon microcolumn arrays

    DOE Patents [OSTI]

    Vertes, Akos (Reston, VA); Walker, Bennett N. (Washington, DC)

    2012-02-07T23:59:59.000Z

    The production and use of silicon microcolumn arrays that harvest light from a laser pulse to produce ions are described. The systems of the present invention seem to behave like a quasi-periodic antenna array with ion yields that show profound dependence on the plane of laser light polarization and the angle of incidence. By providing photonic ion sources, this enables enhanced control of ion production on a micro/nano scale and direct integration with miniaturized analytical devices.

  3. Nanophotonic production, modulation and switching of ions by silicon microcolumn arrays

    DOE Patents [OSTI]

    Vertes, Akos; Walker, Bennett N.

    2013-09-10T23:59:59.000Z

    The production and use of silicon microcolumn arrays that harvest light from a laser pulse to produce ions are described. The systems of the present invention seem to behave like a quasi-periodic antenna array with ion yields that show profound dependence on the plane of laser light polarization and the angle of incidence. By providing photonic ion sources, this enables enhanced control of ion production on a micro/nano scale and direct integration with miniaturized analytical devices.

  4. Single crystal growth and superconductivity of Ca(Fe1-xCox)2As2

    SciTech Connect (OSTI)

    Hu, Rongwei; Ran, Sheng; Budko, Serguei; Straszheim, Warren E.; Canfield, Paul C.

    2012-05-18T23:59:59.000Z

    We report the single crystal growth of Ca(Fe1-xCox)2As2 (0 <= x <= 0.082) from Sn flux. The temperature-composition phase diagram is mapped out based on the magnetic susceptibility and electrical transport measurements. Phase diagram of Ca(Fe1-xCox)2As2 is qualitatively different from those of Sr and Ba, it could be due to both the charge doping and structural tuning effects associated with Co substitution.

  5. Mo{sub 5}Si{sub 3} single crystals: Physical properties and mechanical behavior

    SciTech Connect (OSTI)

    Chu, F.; Thoma, D.J.; McClellan, K.J.; Peralta, P.

    1998-12-01T23:59:59.000Z

    The materials processing, physical properties and mechanical behavior of an ultra-high temperature structural silicide, Mo{sub 5}Si{sub 3}, have been studied. High purity single crystals of Mo{sub 5}Si{sub 3} have been synthesized by both optical floating zone and Czochralski methods. The thermal and elastic properties of the MO{sub 5}Si{sub 3} single crystals were experimentally measured. Results show that Mo{sub 5}Si{sub 3} has significant thermal expansion anisotropy along the a and c directions with {alpha}{sub c}/{alpha}{sub a} = 2.2. Single crystal elastic moduli of Mo{sub 5}Si{sub 3} indicate that it has less elastic anisotropy and lower shear moduli than transition metal disilicides. Tensile stresses of up to 1.8 GPa can develop at grain boundaries after cooling from the melting point due to the thermal expansion mismatch in Mo{sub 5}Si{sub 3}, causing grain boundary cracking during processing of polycrystals. Room temperature Vickers indentation tests on (100) and (001) planes have been performed with different indenter diagonal orientations. The orientation dependence of hardness and fracture toughness of Mo{sub 5}Si{sub 3} single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. A comparison of Mo{sub 5}Si{sub 3} with other high temperature structural silicides, e.g., C11{sub b} and C40 transition metal disilicides, is discussed.

  6. Thermographic analyses of the growth of Cd1-xZnxTe single crystals

    SciTech Connect (OSTI)

    Kopach, O.V.; Bolotnikov, A.; Shcherbak, Larysa P.; Fochuk, Petro M.; and James, Ralph B.

    2010-08-01T23:59:59.000Z

    Bulk Cd1-xZnxTe (0single crystals for gamma-ray detectors are grown mainly from near-stoichiometric melts. We discuss the influence of the thermal pre-history of the melts (superheating, thermo-cycling, and cooling rate) on various physical properties based on our thermographic analyses, electrical conductivity and viscosity measurements. Increasing the Zn content causes non-monotonic dependencies in the quality of the crystals structure.

  7. Development of large Grain/Single Crystal Niobium Cavity Technology at Jefferson Lab

    SciTech Connect (OSTI)

    Peter Kneisel; J. Sekutowicz; T. Carneiro; G. Ciovati

    2006-10-31T23:59:59.000Z

    Approximately two years ago we started to develop high performance niobium accelerating cavities based on large grain or single crystal high purity niobium. We have fabricated and tested 15 single cell cavities of various shapes and frequencies between 1300 MHz and 2300 MHz using material from a total of 9 different very large grain niobium ingots from four niobium suppliers. The materials differed not only in grain sizes, but also in RRR ? value and in the amount of Ta contained in the material. In one ingot supplied by CBMM the central grain exceeded 7 inches in diameter and this was used to fabricate two 2.2 GHz cavities. A single crystal 1300 MHz mono-cell cavity was also produced at DESY by rolling out a single crystal to the size required for this cavity. It was sent to Jlab for surface treatment and testing. In addition, we have fabricated three 7-cell cavities: two of the Jlab high gradient (HG) shape and one of the ILC Low Loss shape. Two 9-cell TESLA shape cavities are presently in fabrication at Jlab and are close to completion.

  8. Single crystal growth and characterization of nearly stoichiometric LiVO{sub 2}

    SciTech Connect (OSTI)

    Tian, W.; Chisholm, M.F.; Khalifah, P.G.; Jin, R.; Sales, B.C.; Nagler, S.E.; Mandrus, D

    2004-07-02T23:59:59.000Z

    LiVO{sub 2} undergoes an imperfectly understood orbital ordering transition near 500 K resulting in a loss of magnetic moment below the transition. Studies of the transition have been hampered by a lack of high-quality stoichiometric single crystals. Here we report the growth and basic characterization of large, nearly stoichiometric LiVO{sub 2} single crystals. The crystals were characterized by magnetic susceptibility, electrical resistivity, differential scanning calorimetry, and specific heat measurements over a temperature range from 2 to 650 K. A first-order phase transition with large hysteresis near T{sub t}{approx}500 K was observed in all measurements. An anisotropy of the order of 100 was observed in the in-plane versus out-of-plane resistivity, and the inferred semiconducting energy gap was 0.18 eV for Tsingle crystals at temperatures below and above T{sub t}. Superlattice reflections were observed below T{sub t} and disappeared upon heating above the phase transition temperature. Upon cooling below T{sub t}, the supperlattice spots reappeared. Bright field electron micrographs indicate that the crystals develop a roughly hexagonal network of cracks.

  9. Single crystal neutron diffraction study of the magnetic structure of TmNi{sub 2}B{sub 2}C

    SciTech Connect (OSTI)

    Sternlieb, B.; Shapiro, S. [Brookhaven National Lab., Upton, NY (United States); Stassis, C.; Goldman, A.I.; Canfield, P. [Iowa State Univ., Ames, IA (United States)

    1997-02-01T23:59:59.000Z

    Neutron diffraction techniques have been used to study the magnetic structure of single crystals of the magnetic superconductor (T{sub c} {congruent} 11K) TmNi{sub 2}B{sub 2}C. We find that below approximately 1.5K the magnetic moments order in an incommensurate spin wave with propagation vector q{sub m} = q{sub m} (a* +b*) (or q{sub m} = q{sub m} (a* + b*)) with q{sub m} = 0.094 {+-} 0.001. The spin wave is transverse with the moments aligned along the c-axis, and the observation of relatively intense higher order harmonics shows that the modulation is not purely sinusoidal but considerably squared. This incommensurate magnetic structure, which coexists with superconductivity below T{sub N} {congruent} 1.5K, is quite different from those observed in the magnetic superconductors HoNi{sub 2}B{sub 2}C and ErNi{sub 2}B{sub 2}C. The origin of diffraction peaks observed in scans parallel to a* is briefly discussed.

  10. Polarisation independent phase modulation using a blue phase liquid crystal over silicon device

    E-Print Network [OSTI]

    Hyman, Rachel M.; Lorenz, Alexander; Morris, Stephen M.; Wilkinson, Timothy D.

    2014-10-10T23:59:59.000Z

    , Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK 2Department of Engineering Science University of Oxford, Parks Road, Oxford, OX1 3PJ, UK *Corresponding author: rmh61@cam.ac.uk Liquid crystal over silicon... together using 6 ?m spacer bead doped glue. The cell thickness was then measured using the Fabry-Perot interference technique with a spectrometer connected to the microscope (Ocean Optics USB 2000). The cell gap thickness was measured to be 6.4 ± 0.1 ?m...

  11. Light-induced degradation at the silicon/silicon dioxide interface

    SciTech Connect (OSTI)

    Gruenbaum, P.E.; Sinton, R.A.; Swanson, R.M.

    1988-04-25T23:59:59.000Z

    Single-crystal silicon point-contact solar cells show a degradation in their efficiency after being exposed to concentrated sunlight. This change has been linked to an increase in the surface recombination velocity. A similar effect is produced by carrier injection under forward bias. The annealing kinetics, the role of ultraviolet light, and possible causes for the creation of surface states are discussed.

  12. Millimeter size single crystals of superconducting YBa[sub 2]Cu[sub 3]O[sub x

    DOE Patents [OSTI]

    Damento, M.A.; Gschneidner, K.A. Jr.

    1989-04-25T23:59:59.000Z

    A method of growing large, up to 1 mm size single crystals of superconducting YBa[sub 2]Cu[sub 3]O[sub x], wherein x equals from 6.5 to 7.2 is disclosed.

  13. Electrical and mechanical studies of high purity aluminum single crystals at 4.2 K under cyclic strain

    E-Print Network [OSTI]

    Zou, Hong

    1995-01-01T23:59:59.000Z

    The objective of this research is to investigate the effects of orientation on strain hardening and resistivity degradation in high purity aluminum single crystals resulting from uniaxial cyclic strain at 4.2 K. Aluminum crystals with various...

  14. Irradiation damage of single crystal, coarse-grained, and nanograined copper under helium bombardment at 450 °C

    E-Print Network [OSTI]

    Han, Weizhong

    The irradiation damage behaviors of single crystal (SC), coarse-grained (CG), and nanograined (NG) copper (Cu) films were investigated under Helium (He) ion implantation at 450 °C with different ion fluences. In irradiated ...

  15. Advances in the growth of alkaline-earth halide single crystals for scintillator detectors

    SciTech Connect (OSTI)

    Boatner, Lynn A [ORNL; Ramey, Joanne Oxendine [ORNL; Kolopus, James A [ORNL; Neal, John S [ORNL; Cherepy, Nerine [Lawrence Livermore National Laboratory (LLNL); Payne, Stephen A. [Lawrence Livermore National Laboratory (LLNL); Beck, P [Lawrence Livermore National Laboratory (LLNL); Burger, Arnold [Fisk University, Nashville; Rowe, E [Fisk University, Nashville; Bhattacharya, P. [Fisk University, Nashville

    2014-01-01T23:59:59.000Z

    Alkaline-earth scintillators such as strontium iodide and other alkaline-earth halides activated with divalent europium represent some of the most efficient and highest energy resolution scintillators for use as gamma-ray detectors in a wide range of applications. These applications include the areas of nuclear nonproliferation, homeland security, the detection of undeclared nuclear material, nuclear physics and materials science, medical diagnostics, space physics, high energy physics, and radiation monitoring systems for first responders, police, and fire/rescue personnel. Recent advances in the growth of large single crystals of these scintillator materials hold the promise of higher crystal yields and significantly lower detector production costs. In the present work, we describe new processing protocols that, when combined with our molten salt filtration methods, have led to advances in achieving a significant reduction of cracking effects during the growth of single crystals of SrI2:Eu2+. In particular, we have found that extended pumping on the molten crystal-growth charge under vacuum for time periods extending up to 48 hours is generally beneficial in compensating for variations in the alkaline-earth halide purity and stoichiometry of the materials as initially supplied by commercial sources. These melt-pumping and processing techniques are now being applied to the purification of CaI2:Eu2+ and some mixed-anion europium-doped alkaline-earth halides prior to single-crystal growth by means of the vertical Bridgman technique. The results of initial studies of the effects of aliovalent doping of SrI2:Eu2+ on the scintillation characteristics of this material are also described.

  16. Calculations of single crystal elastic constants for yttria partially stabilised zirconia from powder diffraction data

    SciTech Connect (OSTI)

    Lunt, A. J. G., E-mail: alexander.lunt@eng.ox.ac.uk; Xie, M. Y.; Baimpas, N.; Korsunsky, A. M. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom); Zhang, S. Y.; Kabra, S.; Kelleher, J. [ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX (United Kingdom); Neo, T. K. [Specialist Dental Group, Mount Elizabeth Orchard, 3 Mount Elizabeth, #08-03/08-08/08-10, Singapore 228510 (Singapore)

    2014-08-07T23:59:59.000Z

    Yttria Stabilised Zirconia (YSZ) is a tough, phase-transforming ceramic that finds use in a wide range of commercial applications from dental prostheses to thermal barrier coatings. Micromechanical modelling of phase transformation can deliver reliable predictions in terms of the influence of temperature and stress. However, models must rely on the accurate knowledge of single crystal elastic stiffness constants. Some techniques for elastic stiffness determination are well-established. The most popular of these involve exploiting frequency shifts and phase velocities of acoustic waves. However, the application of these techniques to YSZ can be problematic due to the micro-twinning observed in larger crystals. Here, we propose an alternative approach based on selective elastic strain sampling (e.g., by diffraction) of grain ensembles sharing certain orientation, and the prediction of the same quantities by polycrystalline modelling, for example, the Reuss or Voigt average. The inverse problem arises consisting of adjusting the single crystal stiffness matrix to match the polycrystal predictions to observations. In the present model-matching study, we sought to determine the single crystal stiffness matrix of tetragonal YSZ using the results of time-of-flight neutron diffraction obtained from an in situ compression experiment and Finite Element modelling of the deformation of polycrystalline tetragonal YSZ. The best match between the model predictions and observations was obtained for the optimized stiffness values of C11?=?451, C33?=?302, C44?=?39, C66?=?82, C12?=?240, and C13?=?50 (units: GPa). Considering the significant amount of scatter in the published literature data, our result appears reasonably consistent.

  17. Shape of isolated domains in lithium tantalate single crystals at elevated temperatures

    SciTech Connect (OSTI)

    Shur, V. Ya., E-mail: vladimir.shur@usu.ru; Akhmatkhanov, A. R.; Baturin, I. S. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation) [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation); Labfer Ltd., 620014 Ekaterinburg (Russian Federation); Chezganov, D. S.; Lobov, A. I.; Smirnov, M. M. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)] [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

    2013-12-09T23:59:59.000Z

    The shape of isolated domains has been investigated in congruent lithium tantalate (CLT) single crystals at elevated temperatures and analyzed in terms of kinetic approach. The obtained temperature dependence of the growing domain shape in CLT including circular shape at temperatures above 190?°C has been attributed to increase of relative input of isotropic ionic conductivity. The observed nonstop wall motion and independent domain growth after merging in CLT as opposed to stoichiometric lithium tantalate have been attributed to difference in wall orientation. The computer simulation has confirmed applicability of the kinetic approach to the domain shape explanation.

  18. Integration of neutron time-of-flight single-crystal Bragg peaks in reciprocal space

    SciTech Connect (OSTI)

    Schultz, Arthur J [ORNL] [ORNL; Joergensen, Mads [ORNL] [ORNL; Wang, Xiaoping [ORNL] [ORNL; Mikkelson, Ruth L [ORNL] [ORNL; Mikkelson, Dennis J [ORNL] [ORNL; Lynch, Vickie E [ORNL] [ORNL; Peterson, Peter F [ORNL] [ORNL; Green, Mark L [ORNL] [ORNL; Hoffmann, Christina [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    The intensity of single crystal Bragg peaks obtained by mapping neutron time-of-flight event data into reciprocal space and integrating in various ways are compared. These include spherical integration with a fixed radius, ellipsoid fitting and integrating of the peak intensity and one-dimensional peak profile fitting. In comparison to intensities obtained by integrating in real detector histogram space, the data integrated in reciprocal space results in better agreement factors and more accurate atomic parameters. Furthermore, structure refinement using integrated intensities from one-dimensional profile fitting is demonstrated to be more accurate than simple peak-minus-background integration.

  19. The growth and characterization of LiGd?(Mo0?)? single crystals

    E-Print Network [OSTI]

    Reimund, James Allyn

    1981-01-01T23:59:59.000Z

    and was used along with a thermo- electric heater/cooler. The DIP packaging technique also made the samples much more rugged and easier to handle (see figure 11). Figure 11 Holder III a) ceramic package, b) bonding pad, c) conductive high temperature... 1981 Major Subject: Electrical Engineering THE GROWTH AND CHARACTERIZATION OF LiGd (MoO ) SINGLE CRYSTALS A Thesis JAMES ALLYN REIMUND Approved as to style and content by: (R. K. Pandey, Cha~m . o Committee) )() (R. L. Geiger, Member) (T. W...

  20. Electrical properties of PbTe single crystals with excess tellurium

    SciTech Connect (OSTI)

    Bagiyeva, G. Z., E-mail: bagieva-gjulandam@rambler.ru; Mustafayev, N. B.; Abdinova, G. Dj.; Abdinov, D. Sh. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan)

    2011-11-15T23:59:59.000Z

    The effects of excess (up to 0.1 at %) Te atoms and heat treatment at 473 and 573 K for 120 h on the conductivity {sigma}, thermopower {alpha}, and Hall coefficient R of PbTe single crystals are studied. It is shown that excess Te atoms and annealing strongly affect the values and character of the temperature dependences of these parameters and the signs of {alpha} and R at low temperatures, which is caused by the acceptor effect of these atoms and the formation of antisite defects due to localization of Te in vacancies of the lead sublattice upon annealing.

  1. Effect of annealing on the electrical properties of thallium-doped PbTe single crystals

    SciTech Connect (OSTI)

    Ahmedova, G. A., E-mail: gulgunahmed@yahoo.com; Abdinova, G. J.; Abdinov, J. Sh. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan)

    2011-02-15T23:59:59.000Z

    It is found that electrical parameters of PbTe single crystals, the character of the dependences of these parameters on temperature and Tl impurity concentration, and the conductivity type (signs of {alpha} and R) are governed to a great extent by the temperature of preliminary annealing. The cause of this effect is that the concentration of doubly charged vacancies in the tellurium sublattice increases with an increase in the annealing temperature, as a result of which the formation of electrically neutral or singly charged complexes of impurity-vacancy type becomes more likely.

  2. Growth, Structure, and Magnetic Properties of CuFeTe{sub 2} Single Crystals

    SciTech Connect (OSTI)

    Dzhabbarov, A.I.; Orudzhev, S.K.; Guseinov, G.G.; Gakhramanov, N.F. [Institute of Physics, Academy of Sciences of Azerbaijan, pr. Dzhavida 33, Baku, 370143 (Azerbaijan)

    2004-11-01T23:59:59.000Z

    CuFeTe{sub 2} single crystals were grown and the temperature dependence of their magnetic susceptibility in the temperature range 1.8-400 K was investigated. It is found that the magnetic susceptibility shows anomalies at temperatures T{sub s} = 65 and T{sub N} = 125 K. At T > 125 K, the crystal is in the paramagnetic state controlled by Fe{sup 2+} and Cu{sup 2+} ions with an effective magnetic moment of 1.44 {mu}B.

  3. The Resonance Scattering Phenomenon of Fast Negatively Charged Particles in a Single Crystal

    E-Print Network [OSTI]

    Kovalev, Gennady V

    2015-01-01T23:59:59.000Z

    The energy spectrum of the extended attractive potential of a crystallographic row for negatively charged particles has quasi-bound states. It follows that a negatively charged particle with small transversal momentum component ($p_{\\bot} R <<1$) may undergo resonance scattering. Thus the resonance scattering phenomenon can be observed in a single crystal, when fast electrons move with a small glancing angle ($\\theta_0 << 1/pR$) to a crystallographic axis. The calculated results for the electrons and angular widths of resonance peaks are consistent with experimental data.

  4. Modelling off Hugoniot Loading Using Ramp Compression in Single Crystal Copper

    SciTech Connect (OSTI)

    Hawreliak, J; Remington, B A; Lorenzana, H; Bringa, E; Wark, J

    2010-11-29T23:59:59.000Z

    The application of a ramp load to a sample is a method by which the thermodynamic variables of the high pressure state can be controlled. The faster the loading rate, the higher the entropy and higher the temperature. This paper describes moleculer dynamics (MD) simulations with 25 million atoms which investigate ramp loading of single crystal copper. The simulations followed the propagation of a 300ps ramp load to 3Mbar along the [100] direction copper. The simulations were long enough to allow the wave front to steepen into a shock, at which point the simulated copper sample shock melted.

  5. Physical properties of BeAl{sub 6}O{sub 10} single crystals

    SciTech Connect (OSTI)

    Pestryakov, E.V.; Petrov, V.V.; Zubrinov, I.I.; Semenov, V.I.; Trunov, V.I.; Kirpichnikov, A.V. [Department of Quantum Electronics, Institute of Semiconductor Physics, Novosibirsk 630090 (Russia)] [Department of Quantum Electronics, Institute of Semiconductor Physics, Novosibirsk 630090 (Russia); Alimpiev, A.I. [Design and Technological Institute of Monocrystals, Novosibirsk 630058 (Russia)] [Design and Technological Institute of Monocrystals, Novosibirsk 630058 (Russia)

    1997-10-01T23:59:59.000Z

    Single crystals of BeAl{sub 6}O{sub 10}, beryllium hexaaluminate, were grown by the Czochralski method. The optical, acousto-optical, elastic, and a number of thermo-mechanical properties of bulk crystals of BeAl{sub 6}O{sub 10} were investigated in comparison with crystal of BeAl{sub 2}O{sub 4}, chrysoberyl. It has been demonstrated that this material is the promising host for active media of tunable solid state lasers. {copyright} {ital 1997 American Institute of Physics.}

  6. In-Situ Measurement of Crystalline Silicon Modules Undergoing Potential-Induced Degradation in Damp Heat Stress Testing for Estimation of Low-Light Power Performance

    SciTech Connect (OSTI)

    Hacke, P.; Terwilliger, K.; Kurtz, S.

    2013-08-01T23:59:59.000Z

    The extent of potential-induced degradation of crystalline silicon modules in an environmental chamber is estimated using in-situ dark I-V measurements and applying superposition analysis. The dark I-V curves are shown to correctly give the module power performance at 200, 600 and 1,000 W/m2 irradiance conditions, as verified with a solar simulator. The onset of degradation measured in low light in relation to that under one sun irradiance can be clearly seen in the module design examined; the time to 5% relative degradation measured in low light (200 W/m2) was 28% less than that of full sun (1,000 W/m2 irradiance). The power of modules undergoing potential-induced degradation can therefore be characterized in the chamber, facilitating statistical analyses and lifetime forecasting.

  7. Development of a commercial photovoltaic concentrator module

    SciTech Connect (OSTI)

    Saifee, S.T.; Hutchison, G. [Solar Kinetics, Inc., Dallas, TX (United States)

    1992-09-01T23:59:59.000Z

    The ojective of this work was to develop the design and prototype of a commercial high-concentration photovoltaic (PV) module. The design is for a 282-sun point-focus concentrating module. Most of the components, subassemblies, and design features incorporate simplifications and ease of manufacturing. The Solar Kinetics, Inc. (SKI) module is designed to incorporate high-efficiency, single-crystal silicon PV cells. The housing is made with aluminum laminated for voltage stand-off and simultaneously providing high thermal conductivity. The Fresnel lens injection molded by American Optical (AO) as singles. The cell assembly consists of a copper heat spreader, a photovoltaic cell soldered, a top and bottom contact, and a reflective secondary optical element (SOE). The cell assemblies passed all of the initial electrical characterization and high-potential tests. Under environmental cycling, the only bond that failed was the PV cell-to-heat spreader interface. The other components (top contact, bottom contact, SOE) passed all the environmental cycling tests. The cell assemblies were designed to be mounted onto the receiver section with a thermally conductive RTV. This geometry was subjected to environmental testing. There was no delamination of this bond nor was there electrical breakdown when the assemblies were subjected to the hi-pot test. A mock module was fabricated for environmental evaluation. This module was subjected to the humidity/freeze cycling to assess the performance of the lens mounting design. This module was also subjected to the rain test after the humidity/freeze cycling and checked for water leaks. The lens showed small displacement from its original position after the environmental cycling. One tablespoon of water did collect inside the module.

  8. Pair distribution function-derived mechanism of a single-crystal to disordered to single-crystal transformation in a hemilabile metal-organic framework

    SciTech Connect (OSTI)

    Allan, P. K.; Chapman, K. W.; Chupas, P. J.; Hriljac, J. A.; Renouf, C. L.; Lucas, T. C. A.; Morris, R. E. (X-Ray Science Division); (Univ. of St. Andrews); (Univ. of Birmingham)

    2012-01-01T23:59:59.000Z

    Flexible metal-organic frameworks (MOFs) are materials of great current interest. A small class of MOFs show flexibility driven by reversible bonding rearrangements that lead directly to unusual properties. Cu-SIP-3 is a MOF based on the 5-sulfoisophthalate ligand, where the strong copper-carboxylate bonds ensure that the three-dimensional integrity of the structure is retained while allowing bonding changes to occur at the more weakly bonding sulfonate group leading to unusual properties such as the ultra-selective adsorption of only certain gases. While the integrity of the framework remains intact during bonding changes, crystalline order is not retained at all times during the transformations. X-Ray diffraction reveals that highly crystalline single crystals lose order during the transformation before regaining crystallinity once it is complete. Here we show how X-ray pair distribution function analysis can be used to reveal the mechanism of the transformations in Cu-SIP-3, identifying the sequence of atomic displacements that occur in the disordered phase. A similar approach reveals the underlying mechanism of Cu-SIP-3's ultra-selective gas adsorption.

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

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

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

  10. Cooperative Island Growth of Large Area Single-Crystal Graphene by Chemical Vapor Deposition on Cu

    SciTech Connect (OSTI)

    Regmi, Murari [Oak Ridge National Laboratory (ORNL); Rouleau, Christopher [Oak Ridge National Laboratory (ORNL); Puretzky, Alexander A [ORNL; Ivanov, Ilia N [ORNL; Geohegan, David B [ORNL; Chen, Jihua [ORNL; Eastman, Jeffrey [Argonne National Laboratory (ANL); Eres, Gyula [ORNL

    2014-01-01T23:59:59.000Z

    We describe a two-step approach for suppressing nucleation of graphene on Cu using chemical vapor deposition. In the first step, as received Cu foils are oxidized in air at temperatures up to 500 C to remove surface impurities and to induce the regrowth of Cu grains during subsequent annealing in H2 flow at 1040 C prior to graphene growth. In the second step, transient reactant cooling is performed by using a brief Ar pulse at the onset of growth to induce collisional deactivation of the carbon growth species. The combination of these two steps results in a three orders of magnitude reduction in the graphene nucleation density, enabling the growth of millimeter-size single crystal graphene grains. A kinetic model shows that suppressing nucleation promotes a cooperative island growth mode that favors the formation of large area single crystal graphene, and it is accompanied by a roughly 3 orders of magnitude increase in the reactive sticking probability of methane compared to that in random nucleation growth.

  11. Mechanical properties of nanocrystalline and epitaxial TiN films on (100) silicon

    E-Print Network [OSTI]

    Wei, Qiuming

    Mechanical properties of nanocrystalline and epitaxial TiN films on (100) silicon H. Wang, A 2001) We investigated mechanical properties of TiN as a function of microstructure varying from nanocrystalline to single crystal TiN films deposited on (100) silicon substrates. By varying the substrate

  12. Formation of multiple levels of porous silicon for buried insulators and conductors in silicon device technologies

    DOE Patents [OSTI]

    Blewer, Robert S. (Albuquerque, NM); Gullinger, Terry R. (Albuquerque, NM); Kelly, Michael J. (Albuquerque, NM); Tsao, Sylvia S. (Albuquerque, NM)

    1991-01-01T23:59:59.000Z

    A method of forming a multiple level porous silicon substrate for semiconductor integrated circuits including anodizing non-porous silicon layers of a multi-layer silicon substrate to form multiple levels of porous silicon. At least one porous silicon layer is then oxidized to form an insulating layer and at least one other layer of porous silicon beneath the insulating layer is metallized to form a buried conductive layer. Preferably the insulating layer and conductive layer are separated by an anodization barrier formed of non-porous silicon. By etching through the anodization barrier and subsequently forming a metallized conductive layer, a fully or partially insulated buried conductor may be fabricated under single crystal silicon.

  13. Growth of Epitaxial gamma-Al2O3 Films on Rigid Single-Crystal Ceramic Substrates and Flexible, Single-Crystal-Like Metallic Substrates by Pulsed Laser Deposition

    SciTech Connect (OSTI)

    Shin, Junsoo [ORNL; Goyal, Amit [ORNL; Wee, Sung Hun [ORNL

    2009-01-01T23:59:59.000Z

    Epitaxial -Al2O3 thin films were grown on diverse substrates using pulsed laser deposition. The high quality of epitaxial growth and cubic structure of -Al2O3 films was confirmed by x-ray diffraction. SrTiO3 and MgO single crystal substrates were used to optimize the growth conditions for epitaxial -Al2O3 film. Under the optimized conditions, epitaxial -Al2O3 thin films were grown on flexible, single-crystal-like, metallic templates. These included untextured Hastelloy substrates with a biaxially textured MgO layer deposited using ion-beam-assisted-deposition and biaxially textured Ni-W metallic tapes with epitaxially grown and a biaxially textured, MgO buffer layer. These biaxially textured, -Al2O3 films on flexible, single-crystal-like substrates are promising for subsequent epitaxial growth of various complex oxide films used for electrical, magnetic and electronic device applications.

  14. Single crystal growth and characterization of the large-unit-cell compound Cu13Ba

    SciTech Connect (OSTI)

    Jesche, Anton [Ames Laboratory; Budko, Serguei L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

    2013-10-31T23:59:59.000Z

    Single crystals of Cu13Ba were successfully grown out of Ba–Cu self flux. Temperature dependent magnetization, M (T ), electrical resistivity, ?(T)?(T), and specific heat, Cp(T)Cp(T), data are reported. Isothermal magnetization measurements, M(H)M(H), show clear de Haas-van Alphen oscillations at T = 2 K for applied fields as low as View the MathML source?0H=1T. An anomalous behavior of the magnetic susceptibility is observed up to T ? 50 K reflecting the effect of de Haas-van Alphen oscillations at fairly high temperatures. The field- and temperature-dependencies of the magnetization indicate the presence of diluted magnetic impurities with a concentration of the order of 0.01 at.%. Accordingly, the minimum and lower temperature rise observed in the electrical resistivity at and below T = 15 K is attributed to the Kondo-impurity effect.

  15. Single-crystal sapphire tubes as economical probes for optical pyrometry in harsh environments

    SciTech Connect (OSTI)

    Ruzicka, Jakub; Houzvicka, Jindrich; Bok, Jiri; Praus, Petr; Mojzes, Peter

    2011-12-20T23:59:59.000Z

    One-end-sealed single-crystal sapphire tubes are presented as a simple, robust, and economical alternative for bulky lightpipe probes. Thermal radiation from a blackbody cavity created at the inner surface of the sealed end is gathered by a simple lens-based collecting system and transmitted via optical fiber to the remote detection unit. Simplicity and applicability of the concept are demonstrated by the combination of commercially available sapphire tubes with a common optical pyrometer. Radiation thermometers with sapphire tubes as invasive probes can be useful for applications requiring immunity to electromagnetic interference, resistance to harsh environments, simple replacement in the case of failure, and enhanced mechanical firmness, enabling wider range probe positioning inside the medium of interest.

  16. Surface Impedance Measurements of Single Crystal MgB2 Films for Radiofrequency Superconductivity Applications

    SciTech Connect (OSTI)

    Binping Xiao, Xin Zhao, Joshua Spradlin, Charles Reece, Michael Kelley, Teng Tan, Xi Xiaoxing

    2012-07-01T23:59:59.000Z

    We report microstructure analyses and superconducting radiofrequency (SRF) measurements of large scale epitaxial MgB{sub 2} films. MgB{sub 2} films on 5 cm dia. sapphire disks were fabricated by a Hybrid Physical Chemical Vapor Deposition (HPCVD) technique. The electron-beam backscattering diffraction (EBSD) results suggest that the film is a single crystal complying with a MgB{sub 2}(0001) {parallel} Al{sub 2}O{sub 3}(0001) epitaxial relationship. The SRF properties of different film thicknesses (200 nm and 350 nm) were evaluated under different temperatures and applied fields at 7.4 GHz. A surface resistance of 9 {+-} 2 {mu}{Omega} has been observed at 2.2 K.

  17. Laser interactions with embedded Ca metal nanoparticles in single crystal CaF{sub 2}

    SciTech Connect (OSTI)

    Cramer, L.P.; Schubert, B.E.; Petite, P.S.; Langford, S.C.; Dickinson, J.T. [Materials Science Program and Physics Department, Washington State University, Pullman, Washington 99164-2814 (United States)

    2005-04-01T23:59:59.000Z

    Single crystal calcium fluoride (CaF{sub 2}) is an important material for vacuum-ultraviolet optics. Nevertheless, prolonged exposure to energetic radiation can color the material by producing calcium metal nanoparticles. We compare the effectiveness of laser conditioning treatments at wavelengths ranging from the near infrared to the deep ultraviolet in removing this coloration. Treatments at 157, 532, and 1064 nm can significantly reduce the visible coloration due to nanoparticles. In contrast, irradiation at 248 nm has little effect at fluences below the damage threshold for the material employed in this work. We present evidence that the effect of laser irradiation on coloration is principally thermal and is largely confined to the first 50 ns after each laser pulse. We attribute the wavelength dependence of the bleaching process to the wavelength dependence associated with Mie absorption by metal nanoparticles. The consequences of these observations with regard to laser conditioning processes in bulk optical materials are discussed.

  18. Thermal tunability in terahertz metamaterials fabricated on strontium titanate single crystal substrates

    E-Print Network [OSTI]

    Singh, Ranjan; Jia, Q X; Taylor, Antoinette J; Chen, Hou-Tong

    2011-01-01T23:59:59.000Z

    We report an experimental demonstration of thermal tuning of resonance frequency in a planar terahertz metamaterial consisting of a gold split-ring resonator array fabricated on a bulk single crystal strontium titanate (SrTiO3) substrate. Cooling the metamaterial starting from 409 K down to 150 K causes about 50% shift in resonance frequency as compare to its room temperature resonance, and there is very little variation in resonance strength. The resonance shift is due to the temperature-dependent refractive index (or the dielectric constant) of the strontium titanate. The experiment opens up avenues for designing tunable terahertz devices by exploiting the temperature sensitive characteristic of high dielectric constant substrates and complex metal oxide materials.

  19. Detailed Surface Analysis Of Incremental Centrifugal Barrel Polishing (CBP) Of Single-Crystal Niobium Samples

    SciTech Connect (OSTI)

    Palczewski, Ari D.; Hui Tian; Trofimova, Olga; Reece, Charles E.

    2011-07-01T23:59:59.000Z

    We performed Centrifugal Barrel Polishing (CBP) on single crystal niobium samples/coupons housed in a stainless steel sample holder following the polishing recipe developed at Fermi Lab (FNAL) in 2011 \\cite{C. A. Cooper 2011}. Post CBP, the sample coupons were analyzed for surface roughness, crystal composition and structure, and particle contamination. Following the initial analysis each coupon was high pressure rinsed (HRP) and analyzed for the effectiveness of contamination removal. We were able to obtain the mirror like surface finish after the final stage of tumbling, although some defects and embedded particles remained. In addition, standard HPR appears to have little effect on removing embedded particles which remain after each tumbling step, although final polishing media removal was partially affected by standard/extended HPR.

  20. Synthesis, growth, structure determination and optical properties of chalcone derivative single crystal

    SciTech Connect (OSTI)

    Karthi, S., E-mail: girijaeaswaradas@gmail.com; Girija, E. K., E-mail: girijaeaswaradas@gmail.com [Department of Physics, Periyar University, Salem - 636011 (India)

    2014-04-24T23:59:59.000Z

    Acquiring large nonlinear optical (NLO) efficient organic material is essential for the development of optoelectronics and photonic devices. Chalcone is the donor - ? - acceptor - ? - donor (D-?-A-?-D) type conjugated molecule with appreciable hyperpolarizability of potential interest in NLO applications. The addition of vinyl and electron donor groups in the chalcone molecule may enhance the second harmonic generation (SHG) efficiency. Here we report the synthesis, crystal growth and characterization of a chalcone derivative 1-(4-methylphenyl)-5-(4-methoxyphenyl)-penta-2,4-dien-1-one (MPMPP). The MPMPP crystal was grown by slow evaporation solution growth technique from acetone. The grown crystal structure was studied by single crystal X-ray diffraction. The SHG efficiency of the grown crystal was determined by Kurtz and Perry method.

  1. Infrared phonon modes in multiferroic single-crystal FeTe2O5Br

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

    Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

    2013-06-01T23:59:59.000Z

    Reflection and transmission as a function of temperature (7–300 K and 5–300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

  2. Deformation of Diopside Single Crystal at Mantle Pressure 2 TEM Characterization of Deformation Microstructures

    SciTech Connect (OSTI)

    E Amiguet; P Cordier; P Raterron

    2011-12-31T23:59:59.000Z

    The dislocation microstructures of diopside single crystals deformed at high-pressure (4 {<=} P {<=} 9 GPa), high-temperature (1100{sup o} {<=} T {<=} 1400 {sup o}C) using a Deformation-DIA high-pressure apparatus (D-DIA) have been characterized by transmission electron microscopy using weak-beam dark-field (WBDF), precession electron diffraction (PED), large-angle convergent-beam electron diffraction (LACBED) and the thickness-fringe method. Dislocation glide is the dominant deformation mechanism under these conditions. The 1/2<110>{l_brace}110{r_brace} glide is controlled by lattice friction on the edge segments and shows extensive cross-slip. The [001] glide occurs mostly on {l_brace}110{r_brace}; no evidence for [001](010) glide has been found. The [100] dislocations bear a strong lattice friction probably due to complex (out of glide) core structures.

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

    SciTech Connect (OSTI)

    Carmody, M.; Gilmore, A.

    2011-05-01T23:59:59.000Z

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

  4. High power single-crystal fiber CW 946 nm laser and blue generation based on Rubidium-doped PPKTP

    E-Print Network [OSTI]

    Boyer, Edmond

    for high power, continuous wave and polarized laser at 946 nm (fig1.c). We demonstrate a polarized laser. Laurell, "High-power, continous-wave, second harmonic generation at 532 nm in periodically poled KTiOPO4(b)(a) (c) High power single-crystal fiber CW 946 nm laser and blue generation based on Rubidium

  5. Patterned aluminum nanowires produced by electron beam at the surfaces of AlF3 single crystals

    E-Print Network [OSTI]

    Wang, Zhong L.

    Patterned aluminum nanowires produced by electron beam at the surfaces of AlF3 single crystals C is demonstrated for fabricating patterned aluminum nanowires in AlF3 substrate in a scanning electron microscope nanowires of different sizes. The aluminum nanowires may act as nano- interconnects for nanoelectronics

  6. Vacancy hardening in single-crystal TiNx,,001... layers C.-S. Shin, D. Gall,a)

    E-Print Network [OSTI]

    Gall, Daniel

    Vacancy hardening in single-crystal TiNx,,001... layers C.-S. Shin, D. Gall,a) N. Hellgren, J; accepted 27 February 2003 We investigate the effect of N vacancies on the mechanical properties are entirely due to anion vacancies. Hardness values increase continuously, while the elastic modulus decreases

  7. Study of the superconducting gap in RNi2B2C,,RY, Lu... single crystals by inelastic light scattering

    E-Print Network [OSTI]

    Yang, In-Sang

    Study of the superconducting gap in RNi2B2C,,RÃ?Y, Lu... single crystals by inelastic light Initiative Center for Superconductivity, Department of Physics, Pohang University of Science and Technology, 790-390 Pohang, Korea Received 28 February 2000 Superconductivity-induced changes in the electronic

  8. Oxygen self-diffusion ``fast-paths'' in titanite single crystals and a general method for deconvolving self-diffusion

    E-Print Network [OSTI]

    Watson, E. Bruce

    Oxygen self-diffusion ``fast-paths'' in titanite single crystals and a general method most other minerals, titanite rarely if ever forms perfect crystals. In addition to the point defects could occur. During the course of an experimental study of oxygen lattice diffusion in titanite, we

  9. ENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR LINAC

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    by these stimulating results, we proceeded to systematic studies on the positron-production efficiencies with tungstenENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR, Russia R. Chehab, IPNL, IN2P3-CNRS, Universite Claude Bernald 1, France Abstract A new tungsten single

  10. Mesoscale Heterogeneity in the Plastic Deformation of a Copper Single Crystal

    SciTech Connect (OSTI)

    Magid, K R; Florando, J N; Lassila, D H; LeBlanc, M M; Tamura, N; Morris Jr., J W

    2007-02-21T23:59:59.000Z

    The work reported here is part of a 'multiscale characterization' study intended to clarify the deformation pattern in a Cu single crystal deformed in compression. A copper single crystal was oriented for single slip in the (111)[{bar 1}01] slip system and tested to {approx}10% strain in uniaxial compression, using a specifically designed '6 degree of freedom' compressive test device to achieve uniaxial strain. The macroscopic strain field was monitored during the test by optical 'image correlation' methods that mapped the strain field with a spatial resolution of about 100 {micro}m. The strain field was measured on orthogonal surfaces, one of which (the x-face) was oriented perpendicular to [1{bar 2}1] and contained the [{bar 1}01] direction of the preferred slip system. The macroscopic strain produced is an inhomogeneous pattern of broad, crossed shear bands in the x-face. One, the primary band, lay parallel to (111). The second, the 'conjugate' band, was oriented perpendicular to (111) and contains no common slip plane of the fcc crystal. The mesoscopic structure of the inhomogeneous macroscopic deformation pattern was explored with selected area diffraction, using a focused synchrotron radiation polychromatic beam with a resolution of 1-3 {micro}m. Areas within the primary, conjugate and primary + conjugate strain regions of the x-face were identified and mapped for their orientation, excess defect density and shear stress. The mesoscopic defect structure consisted of broad, somewhat irregular primary bands that lay nominally parallel to (111) in a almost periodic distribution with a period of about 30 {micro}m. These primary bands were dominant even in the region of conjugate strain. There were also broad conjugate defect bands, almost precisely perpendicular to the primary bands that tended to bridge primary bands and terminate at them. The residual shear stresses were large (ranging to well above 500 MPa) and strongly correlated with the primary shear bands. The results are compared to the mesoscopic defect patterns found in Cu in etch pit studies done some decades ago.

  11. The Fabrication of an Inverter using Rubrene Single Crystal Organic Transistors C. Corbet, Y. Matsuoka, K. Watanabe, P.I. Yoshihiro Iwasa

    E-Print Network [OSTI]

    Mellor-Crummey, John

    The Fabrication of an Inverter using Rubrene Single Crystal Organic Transistors C. Corbet, Y single crystal devices. The purpose of this project is to fabricate an inverter device using organic by a physical vapor transport method with a nitrogen flow. Inverter devices were fabricated by laminating thus

  12. From Ultrananocrystalline Diamond to Single Crystal Diamond Growth in Hot Filament and Microwave Plasma-Enhanced CVD Reactors: a Unified Model for Growth Rates and

    E-Print Network [OSTI]

    Bristol, University of

    From Ultrananocrystalline Diamond to Single Crystal Diamond Growth in Hot Filament and Microwave, Moscow State UniVersity, 119991 Moscow, Russia ReceiVed: April 29, 2008 CVD Diamond can now be deposited either in the form of single crystal homoepitaxial layers, or as polycrystalline films with crystal sizes

  13. Radiation damage of polyethylene single crystals in electron microscopy between 1 and 2.5 MV. II. The influence of temperature

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1043 Radiation damage of polyethylene single crystals in electron microscopy between 1 and 2.5 MV mécanismes réels décrits par les chimistes. Abstract. 2014 The critical dose measured for polyethylene single. Introduction. Polyethylene single crystals, like every organic sub- stance, lose their crystallinity when

  14. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 4, AUGUST 2005 707 A Single-Crystal Silicon Symmetrical and Decoupled

    E-Print Network [OSTI]

    Akin, Tayfun

    Optical cross-connect system based on the White cell and three-state microelectromechanical system on the optical White cell and a three-state microelectromechanical system tilting mirror array. We describe. Here, however, we are interested in free-space sys- tems using microelectromechanical systems (MEMSs

  15. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 6, DECEMBER 2004 1043 VHF Single-Crystal Silicon Elliptic Bulk-Mode

    E-Print Network [OSTI]

    Ayazi, Farrokh

    - mechanical coupling, elliptic bulk-mode, equivalent electrical circuit, temperature coefficient of frequency-plane vibrations of the disk struc- tures is described using the two-dimensional (2-D) elastic theory. An equivalent mechanical model is extracted from the elliptic bulk-mode shape to predict the dynamic behavior

  16. Prediction method of basic domain structure in Fe3%Si(110) single crystal with grooved surface

    SciTech Connect (OSTI)

    Iwata, K., E-mail: iwata.24h.keiji@jp.nssmc.com [Advanced Technology Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, Futtsu, Chiba 293-8511 (Japan); Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai 980-8577 (Japan); Fujikura, M. [Yawata R and D Laboratories, Nippon Steel and Sumitomo Metal Corporation, Tobata, Kitakyushu, Fukuoka 804-8501 (Japan); Arai, S. [Steel Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, Futtsu, Chiba 293-8511 (Japan); Ishiyama, K. [Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai 980-8577 (Japan)

    2014-05-07T23:59:59.000Z

    This paper proposes the method to accurately predict the 180° basic domain width (D{sub w}) in demagnetized states of the grooved Fe3%Si(110) single crystal with the tilt angle of [001] out of the sheet surface (?). The evaluation of D{sub w} enables the estimation of the anomalous eddy current losses. In this paper, D{sub w} is optimized to minimize the magnetic Gibbs free energy represented by vector potentials using the finite element method and the conjugate gradient method. The ?*-method is adopted to approximate the magnetization relaxation. The stray field energy generated by the magnetic charges occurring on both grooves cross section and sheet surfaces is considered in our proposed method. The validity of the proposed method was confirmed by comparison with the observed D{sub w}. As a result, we could reveal the ? dependence of D{sub w} against the groove depth. Moreover, the theoretical threshold of the domain refinement due to the grooves has been suggested.

  17. First order phase transition and superconductivity in BaNi2As2 single crystals

    SciTech Connect (OSTI)

    Ronning, F [Los Alamos National Laboratory; Kurita, N [Los Alamos National Laboratory; Bauer, E D [Los Alamos National Laboratory; Scott, B L [Los Alamos National Laboratory; Park, T [Los Alamos National Laboratory; Klimczuk, T [Los Alamos National Laboratory; Movshovich, R [Los Alamos National Laboratory; Thompson, J D [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    We report the synthesis and physical properties of single crystals of stoichiometric BaNi{sub 2}As{sub 2} which crystallizes in the ThCr{sub 2}Si{sub 2} structure type with lattice parameters a = 4.112(4) {angstrom} and c = 11.54(2) {angstrom}. Resistivity and heat capacity show a first order phase transition at T{sub 0} = 130 K with a thermal hysteresis of 7 K. The Hall coefficient is weakly temperature dependent from room temperature to 2 K where it has a value of -4 x 10{sup -10} {Omega}-cm/Oe. Resist.ivity, ac-susceptibility, and heat capacity find evidence for bulk superconductivity at T{sub c} = 0.7 K. The Sommerfeld coefficient at T{sub c} is 11.6 {+-} 0.9 mJ/ molK{sup 2}. The upper critical field is anisotropic with initial slopes of dH{sub c2}{sup c}/dT = -0.19 T/K and dH{sub c2}{sup ab}/dT = -0.40 T/K, as determined by resistivity.

  18. Evolution of the Surface Science of Catalysis from Single Crystals to Metal Nanoparticles under Pressure

    SciTech Connect (OSTI)

    Somorjai, Gabor A.; Park, Jeong Y.

    2008-03-06T23:59:59.000Z

    Vacuum studies of metal single crystal surfaces using electron and molecular beam scattering revealed that the surface atoms relocate when the surface is clean (reconstruction) and when it is covered by adsorbates (adsorbate induced restructuring). It was also discovered that atomic steps and other low coordination surface sites are active for breaking chemical bonds (H-H, O=O, C-H, C=O and C-C) with high reaction probability. Investigations at high reactant pressures using sum frequency generation (SFG)--vibrational spectroscopy and high pressure scanning tunneling microscopy (HPSTM) revealed bond breaking at low reaction probability sites on the adsorbate-covered metal surface, and the need for adsorbate mobility for continued turnover. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in two-dimensional thin film form or deposited in mesoporous three-dimensional oxides. Studies of reaction selectivity in multipath reactions (hydrogenation of benzene, cyclohexene and crotonaldehyde) showed that reaction selectivity depends on both nanoparticle size and shape. The oxide-metal nanoparticle interface was found to be an important catalytic site because of the hot electron flow induced by exothermic reactions like carbon monoxide oxidation.

  19. TEM and SIMS Analysis of (100), (110), and (111) Single Crystal Niobium

    SciTech Connect (OSTI)

    A. D. Batchelor; D. N. Leonard; P. E. Russell; F. A. Stevie; D. P. Griffis; G. R. Myneni

    2006-10-30T23:59:59.000Z

    Single crystal niobium specimens of (100), (110) and (111) crystal orientations have been analyzed using TEM and SIMS. The TEM specimens were prepared using Focused Ion Beam (FIB) and show niobium oxide thicknesses ranging from 4.9 to 8.3 nm for the three specimens after buffer chemical polishing. The oxide layers appear uniform and no significant sub-oxide region was noted. SIMS analysis was made for all three orientations on hydrogen, carbon, and oxygen before and after heat treatments at 90, 600, and 1250ºC. Hydrogen is at a high level between the oxide layer and niobium, but at a relatively low level in the oxide. No high oxygen concentration region was noted in the niobium below the oxide. C contamination on the surface is detected mainly at the surface. Analysis after heat treatments showed some decrease in hydrogen after the 600ºC heat treatment, and significant oxidation of the niobium after the 1250ºC heat treatment.

  20. Barium iron arsenide, barium cobalt arsenide, barium nickel arsenide single crystals and superconductivity upon cobalt doping

    SciTech Connect (OSTI)

    Ronning, Filip [Los Alamos National Laboratory; Sefat, A S [ORNL; Mcguire, M M [ORNL; Sales, B [ORNL; Jin, R [ORNL; Mandrus, D [ORNL

    2009-01-01T23:59:59.000Z

    The crystal structure and physical properties of BaFe{sub 2}As{sub 2}, BaCo{sub 2}As{sub 2}, and BaNi{sub 2}As{sub 2} single crystals are surveyed. BaFe{sub 2}As{sub 2} gives a magnetic and structural transition at T{sub N} = 132(1) K, BaCo{sub 2}As{sub 2} is a paramagnetic metal, while BaNi{sub 2}As{sub 2} has a structural phase transition at T{sub 0} = 131 K, followed by superconductivity below {Tc} = 0.69 K. The bulk superconductivity in Co-doped BaFe{sub 2}As{sub 2} below {Tc} = 22 K is demonstrated by resistivity, magnetic susceptibility, and specific heat data. In contrast to the cuprates, the Fe-based system appears to tolerate considerable disorder in the transition metal layers. First principles calculations for BaFe{sub 1.84}Co{sub 0.16}As{sub 2} inter-band scattering due to Co is weak.

  1. Pressure effect on ionic conductivity in yttrium-oxide-doped single-crystal zirconium oxide

    SciTech Connect (OSTI)

    Park, E.T.; Park, J.H.

    1998-06-01T23:59:59.000Z

    In this study, the authors investigated the effect of pressure on the ionic conductivity of a 9.5 mol% yttria-stabilized zirconia (YSZ) single crystal. The experiment was conducted in the elastic region, and the oxygen ion transport number was unity (t{sub ion} > 0.99999). A conventional four-probe DC method was used to measure the ionic conductivity of the rectangular-shaped sample under uniaxial pressures up to 600 atm at 750 C in air. Measured ionic conductivity decreased as applied pressure increased. Based on henry Eyring`s absolute reaction rate theory, which states that the calculated activation volume has a positive value ({Delta}V{sup 2} = 2.08 cm{sup 3}/mol of O{sup {minus}2}) for oxygen ion transport in the fluoride cubic lattice, they concluded that the results they obtained could be explained by an oxygen ion transport mechanism. This mechanism can explain the fact that the interionic distance increases during oxygen ion transport from one unit cell to neighboring unit cells.

  2. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect (OSTI)

    Kagan, Harris; Kass, Richard; Gan, K.K.

    2014-01-23T23:59:59.000Z

    With the LHC upgrades in 2013, and further LHC upgrades scheduled in 2018, most LHC experiments are planning for detector upgrades which require more radiation hard technologies than presently available. At present all LHC experiments now have some form of diamond detector. As a result Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of all LHC experiments. Moreover CVD diamond is now being discussed as an alternative sensor material for tracking very close to the interaction region of the HL-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications. Our accomplishments include: • Developed a two U.S.companies to produce electronic grade diamond, • Worked with companies and acquired large area diamond pieces, • Performed radiation hardness tests using various proton energies: 70 MeV (Cyric, Japan), 800 MeV (Los Alamos), and 24 GeV (CERN).

  3. Conductivity anisotropy in the doped Bi{sub 2}Te{sub 3} single crystals

    SciTech Connect (OSTI)

    Abdullaev, N. A., E-mail: anadir@azintex.com; Kakhramanov, S. Sh.; Kerimova, T. G.; Mustafayeva, K. M. [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan); Nemov, S. A. [St. Petersburg State Polytechnical University (Russian Federation)

    2009-02-15T23:59:59.000Z

    Temperature dependences (temperature range T = 0.5-300 K) of resistivity in the plane of layers and in the direction perpendicular to the layers, and the galvanomagnetic effects in undoped and doped Bi{sub 2}Te{sub 3} single crystals are studied (magnetic field H < 80 kOe, T = 0.5-4.2 K). It is shown that upon doping of Bi{sub 2}Te{sub 3} with the Group III atoms (In and B), conductivity anisotropy increases mainly due to an increase in resistivity in the direction perpendicular to the layers. This fact makes it possible to assume that the atoms of these impurities are incorporated mainly into the van der Waal gaps between the layers upon doping. It is also revealed that, upon doping of Bi{sub 2}Te{sub 3} with In and B, the temperature dependence of conductivity becomes weaker, which indicates an increase in the role of scattering by defects in scattering mechanisms. The concentrations and mobilities of charge carriers, values of the Hall factor conditioned by the anisotropy of effective masses and orientation of ellipsoids with respect to crystallographic axes, areas of the extreme section of the Fermi surface by the plane perpendicular to the direction of the magnetic field, and the Fermi energy are evaluated.

  4. Superconductivity and Physical Properties of CaPd2Ge2 Single Crystals

    SciTech Connect (OSTI)

    Anand, V K [Ames Laboratory; Kim, Hyunsoo [Ames Laboratory; Tanatar, Makariy A [Ames Laboratory; Prozorov, Ruslan [Ames Laboratory; Johnston, David C [Ames Laboratory

    2014-10-08T23:59:59.000Z

    We present the superconducting and normal state properties of CaPd2Ge2 single crystals investigated by magnetic susceptibility ?, isothermal magnetization M, heat capacity Cp, in-plane electrical resistivity ? and London penetration depth ? versus temperature T and magnetic field H measurements. Bulk superconductivity is inferred from the ?(T) and Cp(T) data. The ?(T) data exhibit metallic behavior and a superconducting transition with Tc onset = 1.98 K and zero resistivity at Tc 0 = 1.67 K. The ?(T) reveals the onset of superconductivity at 2.0 K. For T > 2.0 K, the ?(T) and M(H) are weakly anisotropic paramagnetic with ?ab > ?c. The Cp(T) data confirm the bulk superconductivity below Tc = 1.69(3) K. The superconducting state electronic heat capacity is analyzed within the framework of a single-band ?-model of BCS superconductivity and various normal and superconducting state parameters are estimated. Within the ?-model, the Cp(T) data and the ab plane ?(T) data consistently indicate a moderately anisotropic s-wave gap with ?(0)/kBTc ? 1.6, somewhat smaller than the BCS value of 1.764. The relationship of the heat capacity jump at Tc and the penetration depth measurement to the anisotropy in the s-wave gap is discussed.

  5. Spectroscopy of Charge Carriers and Traps in Field-Doped Single Crystal Organic Semiconductors

    SciTech Connect (OSTI)

    Zhu, Xiaoyang

    2014-12-10T23:59:59.000Z

    The proposed research aims to achieve quantitative, molecular level understanding of charge carriers and traps in field-doped crystalline organic semiconductors via in situ linear and nonlinear optical spectroscopy, in conjunction with transport measurements and molecular/crystal engineering. Organic semiconductors are emerging as viable materials for low-cost electronics and optoelectronics, such as organic photovoltaics (OPV), organic field effect transistors (OFETs), and organic light emitting diodes (OLEDs). Despite extensive studies spanning many decades, a clear understanding of the nature of charge carriers in organic semiconductors is still lacking. It is generally appreciated that polaron formation and charge carrier trapping are two hallmarks associated with electrical transport in organic semiconductors; the former results from the low dielectric constants and weak intermolecular electronic overlap while the latter can be attributed to the prevalence of structural disorder. These properties have lead to the common observation of low charge carrier mobilities, e.g., in the range of 10-5 - 10-3 cm2/Vs, particularly at low carrier concentrations. However, there is also growing evidence that charge carrier mobility approaching those of inorganic semiconductors and metals can exist in some crystalline organic semiconductors, such as pentacene, tetracene and rubrene. A particularly striking example is single crystal rubrene (Figure 1), in which hole mobilities well above 10 cm2/Vs have been observed in OFETs operating at room temperature. Temperature dependent transport and spectroscopic measurements both revealed evidence of free carriers in rubrene. Outstanding questions are: what are the structural features and physical properties that make rubrene so unique? How do we establish fundamental design principles for the development of other organic semiconductors of high mobility? These questions are critically important but not comprehensive, as the nature of charge carriers is known to evolve as the carrier concentration increases, due to the presence of intrinsic disorder in organic semiconductors. Thus, a complementary question is: how does the nature of charge transport change as a function of carrier concentration?

  6. Single-crystal neutron diffraction studies on Ni-based metal-pnictide superconductor BaNi2As2

    SciTech Connect (OSTI)

    Kothapalli, Karunakar [Los Alamos National Laboratory; Ronning, F [Los Alamos National Laboratory; Bauer, E D [Los Alamos National Laboratory; Schultz, A J [Los Alamos National Laboratory; Nakotte, Heinz [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    We report the results of single-crystal neutron diffraction studies of the superconductor BaNi{sub 2}As{sub 2}. The experiments were performed on a tiny crystal of mass 0.8 mg at several temperatures between 20 and 200 K using the Single Crystal Diffractometer, SCD, at the Los Alamos Neutron Science Center. Above 130 K, BaNi{sub 2}As{sub 2} crystallizes in the tetragonal ThCr{sub 2}Si{sub 2} structure. Our neutron diffraction data corroborate a first-order structural transition around 130 K with a relatively large hysteresis of about 10K, in agreement with observations from bulk studies. The anisotropic thermal displacement coefficients are enhanced along c-axis approaching the transition, and a splitting is observed for in-plane type reflections below the transition, which is evidence for a change in crystal structure.

  7. Synthesis, Crystal Structure, and Magnetism of ?-Fe1.00(2)Se1.00(3) Single Crystals

    SciTech Connect (OSTI)

    Petrovic, C.; Billinge, S.

    2011-06-20T23:59:59.000Z

    Understanding iron-based superconductors requires high-quality impurity-free single crystals. So far they have been elusive for {beta}-FeSe and extraction of intrinsic materials properties has been compromised by several magnetic-impurity phases. Here, we report synchrotron-clean {beta}-FeSe superconducting single crystals grown via LiCl/CsCl flux method. Phase purity yields evidence for a defect-induced weak ferromagnetism that coexists with superconductivity below T{sub c}. In contrast to Fe{sub 1+y}Te-based superconductors, our results reveal that the interstitial Fe(2) site is not occupied and that all contribution to density of states at the Fermi level must come from in-plane Fe(1).

  8. Growth of single-crystal {alpha}-MnO{sub 2} nanorods on multi-walled carbon nanotubes

    SciTech Connect (OSTI)

    Chen Yong [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Key Laboratory of Tropic Biological Resources, MOE, Hainan University, 58 Renmin Road, Haikou 570228 (China); Liu Chenguang; Liu Chang [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Lu Gaoqing [ARC Centre for Functional Nanomaterials, Australian Institute of Bioengineering and Nanotechnology, University of Queensland, QLD 4072 (Australia); Cheng Huiming [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)], E-mail: cheng@imr.ac.cn

    2007-11-06T23:59:59.000Z

    Single-crystal {alpha}-MnO{sub 2} nanorods were grown on multi-walled carbon nanotubes (MWNTs) in H{sub 2}SO{sub 4} aqueous solution. The morphology and microstructure of the composites were examined by transmission electron microscopy, high-resolution transmission electron microscopy (HRTEM), X-ray diffractometry and energy dispersive spectroscopy (EDS). The results show that {alpha}-MnO{sub 2} single-crystal nanorods with a mean diameter of 15 nm were densely grown on the surface of MWNTs. Those MWNTs/MnO{sub 2} composites were used as an electrode material for supercapacitors, and it was found that the supercapacitor performance using MWNTs/MnO{sub 2} composites was improved largely compared to that using pure MWNTs and {alpha}-MnO{sub 2} nanorod mechanically mixed with MWNTs.

  9. TEM and x-ray investigation of single crystal-like zirconia films fabricated by dual ion beam deposition

    SciTech Connect (OSTI)

    Ressler, K.G.; Sonnenberg, N.; Cima, M.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Ceramics Processing Research Lab.

    1996-12-31T23:59:59.000Z

    Single crystal-like yttria-stabilized zirconia (YSZ) thin films have been deposited on amorphous quartz, polycrystalline zirconia, single crystal Si, and Hastelloy substrates using dual ion beam deposition (IBAD). These films are highly crystallographically aligned both normal to and within the film plane. The films are deposited at low substrate temperatures (< 200 C), and the film orientation is substrate independent. 0--20 X-ray diffraction, X-ray rocking curves, X-ray pole figures and X-ray phi scans are used to evaluate the film structure. High resolution cross-sectional TEM is used to examine the evolution of crystallographic film alignment on an amorphous quartz substrate. The data suggest that the evolution of biaxial alignment is nucleation controlled under these conditions.

  10. Tetracene air-gap single-crystal field-effect transistors Yu Xia, Vivek Kalihari, and C. Daniel Frisbiea

    E-Print Network [OSTI]

    Rogers, John A.

    Tetracene air-gap single-crystal field-effect transistors Yu Xia, Vivek Kalihari, and C. Daniel FETs utilizing an air or vacuum gap as the gate dielectric. The linear mobility of the device can be as high as 1.6 cm2 /V s in air, with a subthreshold slope lower than 0.5 V nF/decade cm2 . By changing

  11. EPR investigation of defects in Bi12GeO20:Cr single crystal irradiated by high energy uranium ions

    E-Print Network [OSTI]

    Stefaniuk, I; Rogalska, I; Wróbel, D

    2013-01-01T23:59:59.000Z

    The results of investigations of EPR spectra of chromium doped $Bi_{12} GeO_{20} (BGO)$ single crystals are presented. The crystals were studied before and after irradiation by the $^{235}U$ ions with energy 9.47 MeV/u and fluency $5 \\cdot 10^{2} cm^{-2}$. The effect of heating irradiated samples in air on the EPR spectra is also studied.

  12. The crystal structure of {pi}-ErBO{sub 3}: New single-crystal data for an old problem

    SciTech Connect (OSTI)

    Pitscheider, Almut [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Kaindl, Reinhard [Institut fuer Mineralogie und Petrographie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52, A-6020 Innsbruck (Austria); Oeckler, Oliver [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5-13, D-81377 Muenchen (Germany); Huppertz, Hubert, E-mail: Hubert.Huppertz@uibk.ac.a [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria)

    2011-01-15T23:59:59.000Z

    Single crystals of the orthoborate {pi}-ErBO{sub 3} were synthesized from Er{sub 2}O{sub 3} and B{sub 2}O{sub 3} under high-pressure/high-temperature conditions of 2 GPa and 800 {sup o}C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, with the lattice parameters a=1128.4(2) pm, b=652.6(2) pm, c=954.0(2) pm, and {beta}=112.8(1){sup o} (R{sub 1}=0.0124 and wR{sub 2}=0.0404 for all data). -- graphical abstract: The first satisfying single-crystal structure determination of {pi}-ErBO{sub 3} sheds light on the extensively discussed structure of {pi}-orthoborates. The application of light pressure during the solid state synthesis yielded in high-quality crystals, due to pressure-induced crystallization. Research highlights: {yields} High-quality single crystals of {pi}-ErBO{sub 3} were prepared via high-pressure-induced crystallization. {yields} At least five different space groups for the rare-earth {pi}-orthoborates are reported. {yields} {pi}-ErBO{sub 3} is isotypic to the pseudowollastonite-type CaSiO{sub 3}. {yields} Remaining ambiguities regarding the structure of the rare-earth {pi}-orthoborates are resolved.

  13. Method of forming crystalline silicon devices on glass

    DOE Patents [OSTI]

    McCarthy, A.M.

    1995-03-21T23:59:59.000Z

    A method is disclosed for fabricating single-crystal silicon microelectronic components on a silicon substrate and transferring same to a glass substrate. This is achieved by utilizing conventional silicon processing techniques for fabricating components of electronic circuits and devices on bulk silicon, wherein a bulk silicon surface is prepared with epitaxial layers prior to the conventional processing. The silicon substrate is bonded to a glass substrate and the bulk silicon is removed leaving the components intact on the glass substrate surface. Subsequent standard processing completes the device and circuit manufacturing. This invention is useful in applications requiring a transparent or insulating substrate, particularly for display manufacturing. Other applications include sensors, actuators, optoelectronics, radiation hard electronics, and high temperature electronics. 7 figures.

  14. Method of forming crystalline silicon devices on glass

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA)

    1995-01-01T23:59:59.000Z

    A method for fabricating single-crystal silicon microelectronic components on a silicon substrate and transferring same to a glass substrate. This is achieved by utilizing conventional silicon processing techniques for fabricating components of electronic circuits and devices on bulk silicon, wherein a bulk silicon surface is prepared with epitaxial layers prior to the conventional processing. The silicon substrate is bonded to a glass substrate and the bulk silicon is removed leaving the components intact on the glass substrate surface. Subsequent standard processing completes the device and circuit manufacturing. This invention is useful in applications requiring a transparent or insulating substrate, particularly for display manufacturing. Other applications include sensors, actuators, optoelectronics, radiation hard electronics, and high temperature electronics.

  15. Performance Test of Amorphous Silicon Modules in Different Climates - Year Four: Progress in Understanding Exposure History Stabilization Effects; Preprint

    SciTech Connect (OSTI)

    Ruther, R.; Montenegro, A. A.; del Cueto, J.; Rummel, S.; Anderberg, A.; von Roedern, B.; Tamizh-Mani, G.

    2008-05-01T23:59:59.000Z

    The four-year experiment involved three identical sets of thin-film a-Si modules from various manufacturers deployed outdoors simultaneously in three sites with distinct climates. Each PV module set spent a one-year period at each site before a final period at the original site where it was first deployed.

  16. Mapping mesoscale heterogeneity in the plastic deformation of a copper single crystal

    SciTech Connect (OSTI)

    Magid, K. R.; Florando, J.N.; Lassila, D.H.; Leblanc, M.M.; Tamura, N.; Morris Jr, J. W.

    2008-10-01T23:59:59.000Z

    The work reported here is part of a 'multiscale characterization' study of heterogeneous deformation patterns in metals. A copper single crystal was oriented for single slip in the (111)[{bar 1}01] slip system and tested to {approx}10% strain in roughly uniaxial compression. The macroscopic strain field was monitored during the test by optical 'image correlation'. The strain field was measured on orthogonal surfaces, one of which (the x-face) was oriented perpendicular to [1{bar 2}1] and contained the [{bar 1}01] direction of the preferred slip system. The macroscopic strain developed in an inhomogeneous pattern of broad, crossed shear bands in the x-face. One, the primary band, lay parallel to (111). The second, the 'conjugate' band, was oriented perpendicular to (111) with an overall ({bar 1}01) habit that contains no common slip plane of the fcc crystal. The mesoscopic deformation pattern was explored with selected area diffraction, using a focused synchrotron radiation polychromatic beam with a resolution of 1-3 {micro}m. Areas within the primary, conjugate and mixed (primary + conjugate) strain regions of the x-face were identified and mapped for their orientation, excess defect density and shear stress. The mesoscopic defect structure was concentrated in broad, somewhat irregular primary bands that lay nominally parallel to (111) in an almost periodic distribution with a period of about 30 {micro}m. These primary bands were dominant even in the region of conjugate strain. There were also broad conjugate defect bands, almost precisely perpendicular to the primary bands, that tended to bridge primary bands and terminate at them. The residual shear stresses were large (ranging to well above 500 MPa) and strongly correlated with the primary shear bands; interband stresses were small. The maximum resolved shear stresses within the primary bands were oriented out of the plane of the bands, and, hence, could not recover the dislocation structure in the bands. The maximum resolved shear stresses in the interband regions lay predominantly in {l_brace}111{r_brace} planes. The results are compared to the mesoscopic defect patterns found in Cu in etch pit studies done some decades ago, which also revealed a mesoscopic dislocation structure made up of orthogonal bands.

  17. Method of bonding single crystal quartz by field-assisted bonding

    DOE Patents [OSTI]

    Curlee, Richard M. (Tijeras, NM); Tuthill, Clinton D. (Edgewood, NM); Watkins, Randall D. (Albuquerque, NM)

    1991-01-01T23:59:59.000Z

    The method of producing a hermetic stable structural bond between quartz crystals includes providing first and second quartz crystals and depositing thin films of borosilicate glass and silicon on portions of the first and second crystals, respectively. The portions of the first and second crystals are then juxtaposed in a surface contact relationship and heated to a temperature for a period sufficient to cause the glass and silicon films to become electrically conductive. An electrical potential is then applied across the first and second crystals for creating an electrostatic field between the adjoining surfaces and causing the juxtaposed portions to be attracted into an intimate contact and form a bond for joining the adjoining surfaces of the crystals.

  18. Dielectric, hypersonic, and domain anomalies of ,,PbMg13Nb23O3...1x,,PbTiO3...x single crystals

    E-Print Network [OSTI]

    Dielectric, hypersonic, and domain anomalies of ,,PbMg1Ã?3Nb2Ã?3O3...1Ã?x,,PbTiO3...x single crystals

  19. Scanning Josephson Tunneling Microscopy of Single Crystal Bi2Sr2CaCu2O8+delta with a Conventional Superconducting Tip

    E-Print Network [OSTI]

    Kimura, H.

    2010-01-01T23:59:59.000Z

    materials in the Josephson junction where, Ic is theYBCO) single crystal Josephson junctions can be explained byfor Pb/I/Pb STM Josephson junctions near zero bias with

  20. Chain-oxygen ordering in twin-free YBa2Cu3O7-single crystals driven by 20-keV electron irradiation

    E-Print Network [OSTI]

    Johansen, Tom Henning

    Chain-oxygen ordering in twin-free YBa2Cu3O7- single crystals driven by 20-keV electron irradiation 2005 We have examined the effects of 20-keV electron irradiation on the -Cu 1 -O 1 - n chain-oxygen arrange- ments in oxygen-deficient but otherwise twin-free YBa2Cu3O7- single crystals. Comparison

  1. Optically detected cyclotron resonance in heavily boron-doped silicon nanostructures on n-Si (100)

    SciTech Connect (OSTI)

    Bagraev, N. T., E-mail: Bagraev@mail.ioffe.ru; Kuzmin, R. V.; Gurin, A. S.; Klyachkin, L. E.; Malyarenko, A. M. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Mashkov, V. A. [Saint Petersburg State Polytechnical University (Russian Federation)

    2014-12-15T23:59:59.000Z

    Electron and hole cyclotron resonance at a frequency of 94 GHz is detected by a change in the intensity of photoluminescence lines whose positions are identical to those of dislocation luminescence lines D1 and D2 in single-crystal silicon and in heavily boron-doped silicon nanostructures on the Si (100) surface. The angular dependence of the spectrum of the optically detected cyclotron resonance corresponds to the tensor of the electron and hole effective mass in single-crystal silicon, and the resonance-line width indicates long carrier free-path times close to 100 ps. The results obtained are discussed within the framework of the interrelation of the electron-vibration coupling to charge and spin correlations in quasi-one-dimensional chains of dangling bonds in silicon.

  2. Method for forming silicon on a glass substrate

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA)

    1995-01-01T23:59:59.000Z

    A method by which single-crystal silicon microelectronics may be fabricated on glass substrates at unconventionally low temperatures. This is achieved by fabricating a thin film of silicon on glass and subsequently forming the doped components by a short wavelength (excimer) laser doping procedure and conventional patterning techniques. This method may include introducing a heavily boron doped etch stop layer on a silicon wafer using an excimer laser, which permits good control of the etch stop layer removal process. This method additionally includes dramatically reducing the remaining surface roughness of the silicon thin films after etching in the fabrication of silicon on insulator wafers by scanning an excimer laser across the surface of the silicon thin film causing surface melting, whereby the surface tension of the melt causes smoothing of the surface during recrystallization. Applications for this method include those requiring a transparent or insulating substrate, such as display manufacturing. Other applications include sensors, actuators, optoelectronics, radiation hard and high temperature electronics.

  3. Spontaneous Generation of Voltage in Single-Crystal Gd5Si2Ge2 During Magnetostructural Phase Transformations

    SciTech Connect (OSTI)

    M. Zou; H. Tang; D.L. Schlagel; T.A. Lograsso; K.A. Gschneidner,jr.; V.K. Pecharsky

    2006-04-19T23:59:59.000Z

    The spontaneous generation of voltage (SGV) in single-crystal and polycrystalline Gd{sub 5}Si{sub 2}Ge{sub 2} during the coupled magnetostructural transformation has been examined. Our experiments show reversible, measurable, and repeatable SGV responses of the materials to the temperature and magnetic field. The parameters of the response and the magnitude of the signal are anisotropic and rate dependent. The magnitude of the SGV signal and the critical temperatures and critical magnetic fields at which the SGV occurs vary with the rate of temperature and magnetic-field changes.

  4. Analysis of strained surface layers of ZnO single crystals after irradiation with intense femtosecond laser pulses

    SciTech Connect (OSTI)

    Schneider, Andreas; Sebald, Kathrin; Voss, Tobias [Semiconductor Optics, Institute of Solid State Physics, University of Bremen, D-28359 Bremen (Germany)] [Semiconductor Optics, Institute of Solid State Physics, University of Bremen, D-28359 Bremen (Germany); Wolverson, Daniel [Nanoscience Group, Department of Physics, University of Bath, BA2 7AY Bath (United Kingdom)] [Nanoscience Group, Department of Physics, University of Bath, BA2 7AY Bath (United Kingdom); Hodges, Chris; Kuball, Martin [Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)] [Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

    2013-05-27T23:59:59.000Z

    Structural modifications of ZnO single crystals that were created by the irradiation with femtosecond laser pulses at fluences far above the ablation threshold were investigated with micro-Raman spectroscopy. After light-matter interaction on the femtosecond time scale, rapid cooling and the pronounced thermal expansion anisotropy of ZnO are likely to cause residual strains of up to 1.8% and also result in the formation of surface cracks. This process relaxes the strain only partially and a strained surface layer remains. Our findings demonstrate the significant role of thermoelastic effects for the irradiation of solids with intense femtosecond laser pulses.

  5. Synthesis and characterization of low-OH?fluor-chlorapatite: A single-crystal XRD and NMR spectroscopic study

    SciTech Connect (OSTI)

    McCubbin, Francis M.; Mason, Harris E.; Park, Hyunsoo; Phillips, Brian L.; Parise, John B.; Nekvasil, Hanna; Lindsley, Donald H. (SBU)

    2008-12-12T23:59:59.000Z

    Los-OH apatite of the compositional range Ca{sub 4.99-5.06}(PO{sub 4}){sub 2.98-3.00}F{sub 0.51-0.48}Cl{sub 0.38-0.36}OH{sub 0.14-0.12} was synthesized and characterized structurally by synchrotron-based single-crystal X-ray diffraction (XRD), and multiple nuclear magnetic resonance (NMR) spectroscopic techniques. the average structure is hexagonal with space group P6{sub 3}/m. The presence of scattering in the single-crystal diffraction data set, which is incommensurate within the average hexagonal structure, suggests the presence of localized short-range monoclinic domains. Complex lineshapes in the {sup 31}P and {sup 19}F MAS NMR spectra are also consistent with the presence of an incommensurate phase. No evidence was detected for splitting of the Ca2 site into two distinct sites (as had been previously reported for hexagonal ternary apatities). Structure refinement and {sup 19}F{l_brace}{sup 35}Cl{r_brace} TRAPDOR NMR experiments verified intercolumnal neighboring of F and Cl atoms (inter-column distance of 2.62 {angstrom}) within this low-OH{sup -} apatite suggesting that long-range neighboring of F and Cl within the apatite anion channels is feasible.

  6. Mid- and Far-Infrared Reflection/Absorption Spectroscopy (IRAS) Studies of NO on Rh Single Crystal Surfaces

    SciTech Connect (OSTI)

    Peden, Charles HF; He, Ting; Pilling, M.; Hirschmugl, Carol J.; Gardner, P.

    2001-02-01T23:59:59.000Z

    The NO/CO reaction over Rh metal in automobile catalytic converters is critical to the control of emissions of these pollutant molecules. As part of a program to determine the elementary mechanism(s) of this reaction, we have been performing mid- and far-infrared reflection/absorption spectroscopic (IRAS) measurements of the adsorption and co-adsorption and co-adsorption of NO and CO on Rh single crystal surfaces. Of particular interest is the low-frequency range of the IRAS spectra where we hoped to observe features due to metal-N stretching and/or bending vibrational motions. In particular, we hoped to obtain information regarding the site-requirements for the dissociation of the NO molecule on various Rh single crystal surfaces. An important result from our earlier work is that the selectivity of the reaction for the two nitrogen-containing products, N2 and N2O, is a strong function of the Rh surface structure. On the basis of ancillary data, we suggested that the location of adsorbed NO and N-atoms (formed from dissociation of adsorbed NO) on various Rh surfaces could, perhaps account for the selectivity differences.

  7. Hydrostatic pressure (8 GPa) dependence of electrical resistivity of BaCo{sub 2}As{sub 2} single crystal

    SciTech Connect (OSTI)

    Ganguli, Chandreyee; Matsubayashi, Kazuyuki; Ohgushi, Kenya [Institute for Solid State Physics, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Uwatoko, Yoshiya, E-mail: uwatoko@issp.u-tokyo.ac.jp [Institute for Solid State Physics, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Kanagaraj, Moorthi [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620024 (India); Arumugam, Sonachalam, E-mail: sarumugam1963@yahoo.com [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620024 (India)

    2013-10-15T23:59:59.000Z

    Graphical abstract: - Highlights: • Single crystals of BaCo{sub 2}As{sub 2} were grown by CoAs self-flux method. • We have studied pressure effects (8 GPa) on dc electrical resistivity of BaCo{sub 2}As{sub 2}. • On applied external pressure BaCo{sub 2}As{sub 2} remains a metallic state up to 8 GPa. • Superconductivity is absent in BaCo{sub 2}As{sub 2} because of its proximity to ferromagnetism. - Abstract: The pressure dependence of the electrical resistivity of BaCo{sub 2}As{sub 2} single crystal as a function of temperature was measured at ambient and high pressures up to 8 GPa for the first time using cubic anvil high pressure cell. It is observed that at room temperature the resistivity monotonically decreases with increasing pressure and it remains in the metallic state even at an applied pressure of 8 GPa. From the temperature dependence of the resistivity measurements under pressure, we found that superconductivity is absent up to 8 GPa. The value of the electron's scattering factor (A) is found to be large at ambient pressure and it decreases with the application of pressure, indicating that the substantial electron correlation effect of BaCo{sub 2}As{sub 2} is reduced under pressure, revealing a dramatic change of density of states at the Fermi energy.

  8. Single-crystal sup 40 Ar/ sup 39 Ar dating of the Olorgesailie Formation, southern Kenya rift

    SciTech Connect (OSTI)

    Deino, A. (Geochronology Center of the Inst. of Human Origins, Berkeley, CA (United States)); Potts, R. (Smithsonian Institution, Washington, DC (United States))

    1990-06-10T23:59:59.000Z

    Single-crystal laser fusion {sup 40}Ar/{sup 39}Ar analyses and several conventional bulk fusion {sup 40}K- {sup 40}Ar dates have been used to determine the age of volcaniclastic strata within the Olorgesailie Formation and of associated volcanic and sedimentary units of the southern Kenya rift. In the principal exposures along the southern edge of the Legemunge Plain, the formation spans the interval from approximately 500 to 1,000 ka. Deposition continued to the east along the Ol Keju Nyiro river where a tuff near the top of the formation has been dated at 215 ka. In these exposures, the formation is unconformably overlain by sediments dated at 49 ka. A possible source for the Olorgesailie tephra, the Ol Doinyo Nyokie volcanic complex, contains as ash flow dated at {approximately} 1 Ma, extending the known age range of this complex to encompass that of virtually the entire Olorgesailie Formation in the Legemunge Plain. These geologic examples illustrate the importance of the single-crystal {sup 40}Ar/{sup 39}Ar dating technique whereby contaminant, altered, or otherwise aberrant grains can be identified and eliminated from the determination of eruptive ages for reworked or altered pyroclastic deposits. The authors have presented a computer-modeling procedure based on an inverse-isochron analysis that promotes a more objective approach to trimming {sup 40}Ar/{sup 39}Ar isotope data sets of this type.

  9. High-performance porous silicon solar cell development. Final report, October 1, 1993--September 30, 1995

    SciTech Connect (OSTI)

    Maruska, P. [Spire Corp., Bedford, MA (United States)] [Spire Corp., Bedford, MA (United States)

    1996-09-01T23:59:59.000Z

    The goal of the program was to demonstrate use of porous silicon in new solar cell structures. Porous silicon technology has been developed at Spire for producing visible light-emitting diodes (LEDs). The major aspects that they have demonstrated are the following: porous silicon active layers have been made to show photovoltaic action; porous silicon surface layers can act as antireflection coatings to improve the performance of single-crystal silicon solar cells; and porous silicon surface layers can act as antireflection coatings on polycrystalline silicon solar cells. One problem with the use of porous silicon is to achieve good lateral conduction of electrons and holes through the material. This shows up in terms of poor blue response and photocurrents which increase with increasing reverse bias applied to the diode.

  10. 4765Federal Register / Vol. 77, No. 20 / Tuesday, January 31, 2012 / Notices 1 See Crystalline Silicon Photovoltaic Cells,

    E-Print Network [OSTI]

    Silicon Photovoltaic Cells, Whether or Not Assembled Into Modules, From the People's Republic of China

  11. Field effect in epitaxial graphene on a silicon carbide substrate Sarnoff Corporation, CN5300, Princeton, New Jersey 08543

    E-Print Network [OSTI]

    Feenstra, Randall

    deposition on the surfaces of transition metal or transition metal carbide single crystals, and the physical on a graphitized SiC surface, as opposed to highly conductive metal and metal carbide substrates that require1 Field effect in epitaxial graphene on a silicon carbide substrate Gong Gua) Sarnoff Corporation

  12. Silicon-germanium/gallium phosphide material in high power density thermoelectric modules. Final report, February 1980--September 1981

    SciTech Connect (OSTI)

    Not Available

    1981-12-31T23:59:59.000Z

    This is the final report of work on the characterization of an improved Si-Ge alloy and the fabrication of thermoelectric devices. The improved Si-Ge alloy uses a small addition of GaP in n- and p- type 80 at.% Si-20 at.% Ge; this addition reduces the thermal conductivity, thereby increasing its figure of merit and conversion efficiency. The thermoelectric devices fabricated include multicouples intended for use in Radioisotope Thermoelectric Generators (RTGs) and ring-type modules intended for use with nuclear reactor heat sources. This report summarizes the effort in the material as well as the device areas and discusses individual phases of each area. Results should form basis for further effort.

  13. Photocatalytic Activity of Bulk TiO{sub 2} Anatase and Rutile Single Crystals Using Infrared Absorption Spectroscopy

    SciTech Connect (OSTI)

    Xu Mingchun; Gao Youkun [Department of Physical Chemistry I, Ruhr-Universitaet Bochum, 44780 (Germany); Moreno, Elias Martinez; Kunst, Marinus [Hahn-Meitner-Institut, Glienicker Strasse 100, D-1000 Berlin 39 (Germany); Muhler, Martin [Laboratory of Industrial Chemistry, Ruhr-Universitaet Bochum, 44780 (Germany); Wang Yuemin [Department of Physical Chemistry I, Ruhr-Universitaet Bochum, 44780 (Germany); Laboratory of Industrial Chemistry, Ruhr-Universitaet Bochum, 44780 (Germany); Idriss, Hicham [Department of Chemistry, University of Aberdeen and School of Engineering, Robert Gordon University, AB24 3EU Aberdeen, Scotland (United Kingdom); Woell, Christof [Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany)

    2011-04-01T23:59:59.000Z

    A systematic study on the photocatalytic activity of well-defined, macroscopic bulk single-crystal TiO{sub 2} anatase and rutile samples has been carried out, which allows us to link photoreactions at surfaces of well-defined oxide semiconductors to an important bulk property with regard to photochemistry, the life time of e-h pairs generated in the bulk of the oxides by photon absorption. The anatase (101) surface shows a substantially higher activity, by an order of magnitude, for CO photo-oxidation to CO{sub 2} than the rutile (110) surface. This surprisingly large difference in activity tracks the bulk e-h pair lifetime difference for the two TiO{sub 2} modifications as determined by contactless transient photoconductance measurements on the corresponding bulk materials.

  14. 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.

  15. Synthesis and single crystal x-ray diffraction study of a Schiff base derived from 4-acylpyrazolone and 2-aminophenol

    SciTech Connect (OSTI)

    Sharma, Naresh; Kant, Rajni, E-mail: vivek-gupta2k2@hotmail.com; Gupta, Vivek K., E-mail: vivek-gupta2k2@hotmail.com [Department of Physics and Electronics, University of Jammu, Jammu Tawi - 180006 (India); Jadeja, R. N. [Department of Chemistry, Faculty of Science, The M. S. University of Baroda, Vadodara-390002 (India)

    2014-04-24T23:59:59.000Z

    The title compound, (Z)-1-(3-chlorophenyl)-4[1((2hydroxyphenyl)amino)propylidene] -3-methyl-1H-pyrazol-5(4H)-one was synthesized by refluxing compound 1-(m-chlorophenyl)-3-methyl-4-propionyl-5-pyrazolone, with 2-aminophenol in ethanol. The compound crystallizes in the orthorhombic crystal system with space group Pca2{sub 1} having unit cell parameters: a = 26.2993(8), b = 7.0724(2) and c = 18.7170(5)Å. The structure contains two crystallographically independent molecules, A, and, B, in the asymmetric unit cell. The crystal structure was solved by direct method using single crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R- value of 0.049 for 5207 observed reflections.

  16. Effects of composition and temperature on the large field behavior of [011]{sub C} relaxor ferroelectric single crystals

    SciTech Connect (OSTI)

    Gallagher, John A.; Lynch, Christopher S., E-mail: cslynch@seas.ucla.edu [Department of Mechanical and Aerospace Engineering, University of California Los Angeles, 420 Westwood Plaza, Los Angeles, California 90095 (United States); Tian, Jian [H. C. Materials Corporation, 479 Quadrangle Dr., Suite-E, Bolingbrook, Illinois 60440 (United States)

    2014-08-04T23:59:59.000Z

    The large field behavior of [011]{sub C} cut relaxor ferroelectric lead indium niobate–lead magnesium niobate–lead titanate, xPb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-(1-x-y)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-yPbTiO{sub 3}, single crystals was experimentally characterized in the piezoelectric d{sub 322}-mode configuration under combined mechanical, electrical, and thermal loading. Increasing the concentration of lead indium niobate and decreasing the concentration of lead titanate in compositions near the morphotropic phase boundary resulted in a decrease of mechanical compliance, dielectric permittivity, and piezoelectric coefficients as well as a shift from a continuous to a discontinuous transformation.

  17. Detection of charge transfer processes in Cr-doped SrTiO{sub 3} single crystals

    SciTech Connect (OSTI)

    La Mattina, F. [Physik-Institut der Universitaet Zuerich, Winterthurerstr. 190, CH-8057 Zuerich (Switzerland); IBM Research, Zurich Research Laboratory, Saeumerstr. 4, CH-8803 Rueschlikon (Switzerland); Bednorz, J. G.; Alvarado, S. F. [IBM Research, Zurich Research Laboratory, Saeumerstr. 4, CH-8803 Rueschlikon (Switzerland); Shengelaya, A. [Physics Institute of Tbilisi State University, Chavchavadze 3, GE-0128, Tbilisi (Georgia); Keller, H. [Physik-Institut der Universitaet Zuerich, Winterthurerstr. 190, CH-8057 Zuerich (Switzerland)

    2008-07-14T23:59:59.000Z

    An insulator-to-metal transition is observed in Cr-doped SrTiO{sub 3} single crystals upon extended exposure to a high electric field, namely, electroconditioning (EC). Electron paramagnetic resonance (EPR) and transport measurements under laser irradiation show anticorrelation between the Cr{sup 3+} EPR signal and the electrical current. This proves that the Cr{sup 3+} ions are responsible for the photocurrent that initiates the EC process. We observe the presence of Cr{sup 3+}/Cr{sup 4+} mixed valencies in the bulk in the conducting state. The EPR characterization of the spectra in the conducting state excludes the possibility of a Cr{sup 3+}-oxygen vacancy complex in the bulk as a result of the EC.

  18. Temperature-dependent photocarrier recombination dynamics in Cu{sub 2}ZnSnS{sub 4} single crystals

    SciTech Connect (OSTI)

    Phuong, Le Quang; Kanemitsu, Yoshihiko, E-mail: kanemitu@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Japan Science and Technology Agency, CREST, Uji, Kyoto 611-0011 (Japan); Okano, Makoto; Yamada, Yasuhiro [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Nagaoka, Akira; Yoshino, Kenji [Department of Applied Physics and Electronic Engineering, University of Miyazaki, Miyazaki 889-2192 (Japan)

    2014-02-24T23:59:59.000Z

    Time-resolved photoluminescence (PL) measurements have been used to study the temperature-dependent photocarrier recombination dynamics in Cu{sub 2}ZnSnS{sub 4} (CZTS) single crystals. We found a significant change of nearly four orders of magnitude of the PL decay time, from microseconds at low temperatures to subnanoseconds at room temperature. The slow PL decay at low temperatures indicates localization of the photocarriers at the band tails. Due to the large band tail states, the PL decay time depends strongly on both the photon energy and excitation density. It is pointed out that the drastically enhanced nonradiative recombination at high temperatures is one of the main factors that determine the power conversion efficiency of CZTS-based solar cells.

  19. Growth, structural and optical characterization of L-histidine 4-nitrophenolate (LHPNP) single crystals for NLO applications

    SciTech Connect (OSTI)

    Mahadevan, M., E-mail: devanphysics@gmail.com [Department of Physics, Adhiparasakthi Engineering College, Melmaruvathur - 603319 (India); Ramachandran, K., E-mail: ramach76@yahoo.com [Department of Physics, SRM University - Vadapalani Campus, Chennai -600026 (India); Anandan, P., E-mail: anandantcet@gmail.com [Department of Physics, Thiruvalluvar College of Engineering and Technology, Vandavasi-604 505, India and Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-Ku, Hamamatsu 432-8011 (Japan); Arivanandhan, M., E-mail: arivucz@gmail.com, E-mail: royhaya@ipc.shizuoka.ac.jp; Hayakawa, Y., E-mail: arivucz@gmail.com, E-mail: royhaya@ipc.shizuoka.ac.jp [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-Ku, Hamamatsu 432-8011 (Japan)

    2014-10-15T23:59:59.000Z

    Using slow evaporation solution growth technique, single crystals of L-histidine-4-nitro phenolate has been grown from the solution. Structural analyses were carried out by powder x-ray diffraction, FT-Raman, Fourier Transform Infrared and Nuclear Magnetic Resonance spectral methods to conform the grown crystals. Thermal stability of the grown crystals was studied by thermo-gravimetric (TG) and differential thermal analyses (DTA). UV-Vis spectral analysis has been carried out to find the transparency of the grown crystal. Nonlinear optical property has been confirmed by Kurtz powder technique. The PL measurements were carried out in Perkin Elmer LS 55 Luminescence spectrometer using 410 nm as excitation wavelength. The observed properties have confirmed that the grown crystal is suitable for nonlinear optical applications.

  20. Photoconductivity and luminescence of CuInSe{sub 2} single crystals at a high level of optical excitation

    SciTech Connect (OSTI)

    Guseinov, A. G.; Salmanov, V. M.; Mamedov, R. M. [Baku State University (Azerbaijan)], E-mail: rovshan63@rambler.ru

    2006-04-15T23:59:59.000Z

    The luminance-current and spectral characteristics of photoluminescence of the CuInSe{sub 2} single crystals are studied. The superlinear portion of the excitation-intensity dependence of photoconductivity at low excitation intensities in compensated p-CuInSe{sub 2} crystals is explained on the basis of a recombination model. The emission band that peaked at 0.98 eV in the n-CuInSe{sub 2} photoluminescence spectrum corresponds to radiative recombination of electrons at the donor level with a depth of 0.04 eV. The maximum in the band intensity corresponds to the energy gap between the trap level and the valence band.

  1. Electroluminescence and phototrigger effect in single crystals of GaS{sub x}Se{sub 1-x} alloys

    SciTech Connect (OSTI)

    Kyazym-Zade, A. G., E-mail: bsu_aydin@yahoo.com; Salmanov, V. M.; Mokhtari, A. G.; Dadashova, V. V.; Agaeva, A. A. [Baku State University (Azerbaijan)

    2008-05-15T23:59:59.000Z

    The effects of switching and electroluminescence as well as the interrelation between these effects in single crystals of GaS{sub x}Se{sub 1-x} alloys are detected and studied. It is established that the threshold voltage for switching depends on temperature, resistivity, and composition of alloys, and also on the intensity and spectrum of photoactive light. As a result, a phototrigger effect is observed; this effect arises under irradiation with light from the fundamental-absorption region. Electroluminescence is observed in the subthreshold region of the current-voltage characteristic; the electroluminescence intensity decreases drastically to zero as the sample is switched from a high-resistivity state to a low-resistivity state. Experimental data indicating that the electroluminescence and the switching effect are based on the injection mechanism (as it takes place in other layered crystals of the III-V type) are reported.

  2. A 31?T split-pair pulsed magnet for single crystal x-ray diffraction at low temperature

    SciTech Connect (OSTI)

    Duc, F.; Frings, P.; Nardone, M.; Billette, J.; Zitouni, A.; Delescluse, P.; Béard, J.; Nicolin, J. P.; Rikken, G. L. J. A. [Laboratoire National des Champs Magnétiques Intenses, CNRS-INSA-UJF-UPS, 143, avenue de Rangueil, F-31400 Toulouse (France); Fabrèges, X. [Laboratoire National des Champs Magnétiques Intenses, CNRS-INSA-UJF-UPS, 143, avenue de Rangueil, F-31400 Toulouse (France); Laboratoire Léon Brillouin, UMR12 CEA-CNRS Bât 563 CEA Saclay, 91191 Gif sur Yvette Cedex (France); Roth, T. [European Synchrotron Radiation Facility, Boîte Postale 220, F-38043 Grenoble Cedex (France); European XFEL GmbH, Albert-Einstein-Ring 19, D-22761 Hamburg (Germany); Detlefs, C.; Lesourd, M.; Zhang, L. [European Synchrotron Radiation Facility, Boîte Postale 220, F-38043 Grenoble Cedex (France)

    2014-05-15T23:59:59.000Z

    We have developed a pulsed magnet system with panoramic access for synchrotron x-ray diffraction in magnetic fields up to 31?T and at low temperature down to 1.5?K. The apparatus consists of a split-pair magnet, a liquid nitrogen bath to cool the pulsed coil, and a helium cryostat allowing sample temperatures from 1.5 up to 250?K. Using a 1.15?MJ mobile generator, magnetic field pulses of 60?ms length were generated in the magnet, with a rise time of 16.5?ms and a repetition rate of 2 pulses/h at 31?T. The setup was validated for single crystal diffraction on the ESRF beamline ID06.

  3. High-pressure single-crystal elasticity study of CO{sub 2} across phase I-III transition

    SciTech Connect (OSTI)

    Zhang, Jin S., E-mail: zhang72@illinois.edu; Bass, Jay D. [Department of Geology, University of Illinois, Urbana-Champaign, Illinois 61801 (United States); Shieh, Sean R. [Departments of Earth Sciences and Physics and Astronomy, University of Western Ontario, London, Ontario N6A 5B7 (Canada); Dera, Przemyslaw [Hawaii Institute of Geophysics and Planetology, University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); Prakapenka, Vitali [Center for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637 (United States)

    2014-04-07T23:59:59.000Z

    Sound velocities and elastic moduli of solid single-crystal CO{sub 2} were measured at pressures up to 11.7(3) GPa by Brillouin spectroscopy. The aggregate adiabatic bulk modulus (K{sub S}), shear modulus (G), and their pressure derivatives for CO{sub 2} Phase I are K{sub S0}?=?3.4(6) GPa, G{sub 0}?=?1.8(2) GPa, (dK{sub S}/dP){sub 0}?=?7.8(3), (dG/dP){sub 0}?=?2.5(1), (d{sup 2}K{sub S}/dP{sup 2}){sub 0}?=??0.23(3) GPa{sup ?1}, and (d{sup 2}G/dP{sup 2}){sub 0}?=??0.10(1) GPa{sup ?1}. A small increase of elastic properties was observed between 9.8(1) and 10.5(3) GPa, in agreement with the CO{sub 2} I-III transition pressure determined from previous x-ray diffraction experiments. Above the transition pressure P{sub T}, we observed a mixture dominated by CO{sub 2}-I, with minor CO{sub 2}-III. The CO{sub 2}-I + III mixture shows slightly increased sound velocities compared to pure CO{sub 2}-I. Elastic anisotropy calculated from the single-crystal elasticity tensor exhibits a decrease with pressure beginning at 7.9(1) GPa, which is lower than P{sub T}. Our results coincide with recent X-ray Raman observations, suggesting that a pressure-induced electronic transition is related to local structural and optical changes.

  4. The synthesis, single-crystal structure, optical absorption, and resistivity of Th{sub 2}GeSe{sub 5}

    SciTech Connect (OSTI)

    Koscielski, Lukasz A.; Malliakas, Christos D.; Sarjeant, Amy A.; Ibers, James A., E-mail: ibers@chem.northwestern.edu

    2013-09-15T23:59:59.000Z

    The compound Th{sub 2}GeSe{sub 5} has been synthesized by the reaction of the elements at 1273 K. From a single-crystal study Th{sub 2}GeSe{sub 5} crystallizes in the Ba{sub 5}Si{sub 3} structure type with four formula units in the space group D{sup 8}{sub 4h}?P4/ncc of the tetragonal system in a cell with dimensions a=7.4968(4) Å and c=13.6302(9) Å at 100(2) K. From optical absorption measurements Th{sub 2}GeSe{sub 5} is found to have an optical band gap of 1.92 eV (indirect) or 1.98 eV (direct), consistent with its red color. Th{sub 2}GeSe{sub 5} is a wide gap semiconductor, as indicated by its electrical resistivity at 298 K of 4.37(2)×10{sup 9} ? cm measured on a single crystal. - Graphical abstract: The structure of Th{sub 2}GeSe{sub 5}. Display Omitted - Highlights: • The new compound Th{sub 2}GeSe{sub 5} was synthesized from the elements and recrystallized from Sb{sub 2}Se{sub 3}. • Th{sub 2}GeSe{sub 5} crystallizes in the Ba{sub 5}Si{sub 3} structure type. • The band gap of Th{sub 2}GeSe{sub 5} is1.92 eV and its resistivity shows it to be a wide gap semiconductor.

  5. Single-crystal epitaxial thin films of SrFeO{sub 2} with FeO{sub 2} 'infinite layers'

    SciTech Connect (OSTI)

    Inoue, Satoru; Kawai, Masanori; Shimakawa, Yuichi [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Mizumaki, Masaichiro; Kawamura, Naomi [Japan Synchrotron Radiation Research Institute/SPring-8, Sayo, Hyogo 679-5198 (Japan); Watanabe, Takashi; Tsujimoto, Yoshihiro; Kageyama, Hiroshi; Yoshimura, Kazuyoshi [Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)

    2008-04-21T23:59:59.000Z

    Single-crystal thin films of SrFeO{sub 2}, which is an oxygen-deficient perovskite with ''infinite layers'' of Fe{sup 2+}O{sub 2}, were prepared by using CaH{sub 2} for low-temperature reduction of epitaxial SrFeO{sub 2.5} single-crystal films deposited on KTaO{sub 3} substrates. This reduction process, removing oxygen ions from the perovskite structure framework and causing rearrangements of oxygen ions, topotactically transforms the brownmillerite SrFeO{sub 2.5} to the c-axis oriented SrFeO{sub 2}.

  6. Anisotropic magnetoresistance of single-crystal HoNi2B2C and the interplay of magnetic and superconducting order

    E-Print Network [OSTI]

    Rathnayaka, KDD; Naugle, Donald G.; Cho, BK; Canfield, PC.

    1996-01-01T23:59:59.000Z

    The in-plane resistivity and magnetization measurements as a function of the magnitude and direction of the magnetic field and the temperature are reported for single-crystal samples of the HoNi2B2C magnetic superconductor. Features corresponding...

  7. A phenomenological thermodynamic potential for BaTiO3 single crystals Department of Materials Science and Engineering, The Pennsylvania State University, University Park,

    E-Print Network [OSTI]

    Chen, Long-Qing

    A phenomenological thermodynamic potential for BaTiO3 single crystals Y. L. Lia Department; accepted 4 August 2005; published online 16 September 2005 A phenomenological thermodynamic potential is to con- struct such a thermodynamic potential. II. PHENOMENOLOGICAL THERMODYNAMIC POTENTIAL

  8. PHYSICAL REVIEW B 83, 104526 (2011) Fe Mossbauer study of magnetic ordering in superconducting K0.80Fe1.76Se2.00 single crystals

    E-Print Network [OSTI]

    Ryan, Dominic

    2011-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 83, 104526 (2011) 57 Fe M¨ossbauer study of magnetic ordering in superconducting 31 March 2011) The magnetic ordering of superconducting single crystals of K0.80Fe1.76Se2.00 has been studied between 10 and 550 K using 57 Fe M¨ossbauer spectroscopy. Despite being superconducting below Tsc

  9. The Role of -Al2O3 Single Crystal Support to Pt Nanoparticles Construction Zhongfan Zhang*, Long Li*, Lin-lin Wang**, Sergio I. Sanchez***, Qi Wang****,

    E-Print Network [OSTI]

    Frenkel, Anatoly

    The Role of -Al2O3 Single Crystal Support to Pt Nanoparticles Construction Zhongfan Zhang*, Long Li the preparation of a model Pt/-Al2O3 catalyst and its characterization by a cross-sectional high-resolution electron microscopy (XHREM) method. Pt/-Al2O3 is the most important technologically-relevant heterogeneous

  10. Interaction of wide-band-gap single crystals with 248-nm excimer laser radiation. XI. The effect of water vapor and temperature on laser desorption

    E-Print Network [OSTI]

    Dickinson, J. Thomas

    . Significantly, introducing water vapor lowers the particle velocities and thus the effective surface temperature systems, simultaneous electronic excitation and exposure to aggressive chemicals can acceler- ate etching-induced neutral particle desorption and surface erosion on single- crystal sodium chloride in the presence of low

  11. X-Ray Storage Luminescence of BaFCl:Eu2+ Single Crystals Nomadics, Inc., 1024 South InnoVation Way, Stillwater, Oklahoma 74074

    E-Print Network [OSTI]

    Chen, Reuven

    X-Ray Storage Luminescence of BaFCl:Eu2+ Single Crystals Wei Chen* Nomadics, Inc., 1024 South InnoVed: January 18, 2005; In Final Form: March 22, 2005 Temperature behaviors of X-ray luminescence (XL might not be oxidized to Eu3+ upon X-ray or -irradiation. Instead, the color centers, Cl excitons

  12. Silicone metalization

    DOE Patents [OSTI]

    Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

    2008-12-09T23:59:59.000Z

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  13. Silicone metalization

    DOE Patents [OSTI]

    Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

    2006-12-05T23:59:59.000Z

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  14. Heavy-electron behavior in single-crystal YbNi{sub 2}B{sub 2}C

    SciTech Connect (OSTI)

    Yatskar, A.; Budraa, N.K.; Beyermann, W.P. [University of California, Riverside, California 92521 (United States)] [University of California, Riverside, California 92521 (United States); Canfield, P.C.; Budko, S.L. [Ames Laboratory and Iowa State University, Ames, Iowa 50011 (United States)] [Ames Laboratory and Iowa State University, Ames, Iowa 50011 (United States)

    1996-08-01T23:59:59.000Z

    We have measured the magnetic susceptibility, specific heat, and electrical resistivity on single crystals of the intermetallic borocarbide YbNi{sub 2}B{sub 2}C. An enhanced linear contribution is observed in the specific heat with a Sommerfeld coefficient of 530 mJ/molK{sup 2}, indicative of a heavy-electron system with a Kondo temperature {approximately}10 K. The magnetic susceptibility, which is anisotropic and Curie-Weiss-like at high temperatures, is also consistent with our interpretation of a strongly correlated ground state at low temperatures and crystal-electric- field excitations at higher temperatures. At {ital T}=1.8 K, the Wilson ratio is determined to be 0.85 using the high-temperature effective moment. The resistivity shows a quadratic temperature dependence below 1.5 K with a {ital T}{sup 2} coefficient of 1.2 {mu}{Omega}cmK{sup {minus}2}. Unlike the other members of the series {ital R}Ni{sub 2}B{sub 2}C ({ital R}=Y, Gd{endash}Lu), YbNi{sub 2}B{sub 2}C does not order above our lowest measurement temperature of 0.34 K. The suppression of superconductivity in YbNi{sub 2}B{sub 2}C is consistent with a significantly enhanced hybridization between the conduction electrons and the 4{ital f} states. {copyright} {ital 1996 The American Physical Society.}

  15. Single-crystal structure of vanadium-doped La{sub 2}Mo{sub 2}O{sub 9}

    SciTech Connect (OSTI)

    Alekseeva, O. A., E-mail: olalex@ns.crys.ras.ru; Antipin, A. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Gagor, A.; Pietraszko, A. [Polish Academy of Sciences, Trzebiatowski Institute of Low Temperature and Structure Research (Poland)] [Polish Academy of Sciences, Trzebiatowski Institute of Low Temperature and Structure Research (Poland); Novikova, N. E.; Sorokina, N. I. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Kharitonova, E. P.; Voronkova, V. I. [Moscow State University (Russian Federation)] [Moscow State University (Russian Federation)

    2013-11-15T23:59:59.000Z

    A high-precision X-ray diffraction study of single crystals of two compositions-La{sub 2}Mo{sub 1.78}V{sub 0.22}O{sub 8.89} and La{sub 2}Mo{sub 1.64}V{sub 0.36}O{sub 8.82}-was performed. In the vanadium-doped compounds, as in the structure of the metastable {beta}{sub ms} phase of pure La{sub 2}Mo{sub 2}O{sub 9}, the La and Mo atoms and one of the three oxygen atoms are displaced from the threefold axis, on which they are located in the high-temperature {beta} phase. The structure contains two partially occupied oxygen sites. It was shown that molybdenum atoms are partially replaced by vanadium atoms, which are not involved in the disordering, are located on the threefold axis, and are shifted toward one of the oxygen atoms. This is consistent with the temperature-induced changes in the structure of La{sub 2}Mo{sub 2}O{sub 9} and the changes in the properties of these crystals caused by the introduction of vanadium atoms into the structure.

  16. Crystal structure of La{sub 2}Mo{sub 2}O{sub 9} single crystals doped with bismuth

    SciTech Connect (OSTI)

    Alekseeva, O. A., E-mail: olalex@ns.crys.ras.ru; Verin, I. A.; Sorokina, N. I.; Krasil'nikova, A. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Voronkova, V. I. [Moscow State University, Faculty of Physics (Russian Federation)

    2010-07-15T23:59:59.000Z

    Precision X-ray diffraction studies of La{sub 2-x}Bi{sub x}Mo{sub 2}O{sub 9} (x = 0.04, 0.06, and 0.18) single crystals are performed. It is found that in the compounds doped with bismuth, analogously with the structure of the metastable {beta}{sub ms} phase of pure La{sub 2}Mo{sub 2}O{sub 9} (LM), the La, Mo1, and O1 atoms deviate from the threefold axis on which they are located in the high-temperature {beta} phase. It is shown that bismuth atoms substitute for part of lanthanum atoms and occupy a position at the threefold axis in the neighborhood of the split lanthanum position. The implantation of bismuth atoms in the LM structure results in the return of a part of the molybdenum atoms to the position at the threefold axis. The occupancy of this position is equal to the occupancy of the bismuth atomic position.

  17. Increasing the laser-induced damage threshold of single-crystal ZnGeP{sub 2}

    SciTech Connect (OSTI)

    Zawilski, Kevin T.; Setzler, Scott D.; Schunemann, Peter G.; Pollak, Thomas M. [BAE Systems, Advanced Systems and Technology, P.O. Box 868, MER15-1813, Nashua, New Hampshire 03061-0868 (United States)

    2006-11-15T23:59:59.000Z

    The laser-induced damage threshold (LIDT) of single-crystal zinc germanium phosphide (ZGP), ZnGeP{sub 2}, was increased to 2 J/cm{sup 2} at 2.05 {mu}m and a 10 kHz pulse rate frequency (double the previously measured value of 1 J/cm{sup 2}). This increased LIDT was achieved by improving the polishing of ZGP optical parametric oscillator crystals. Two different polishing techniques were evaluated. Surfaces were characterized using scanning white-light interferometry to determine rms surface roughness and sample flatness. The photon backscatter technique was used to determine the degree of surface and subsurface damage in the sample induced through the fabrication process. The effect of subsurface damage in the samples was studied by removing different amounts of material during polishing for otherwise identical samples. Statistical LIDT was measured using a high-average-power, repetitively Q-switched Tm,Ho:YLF 2.05 {mu}m pump laser. On average, lower surface roughness and photon backscatter measurements were a good indicator of ZGP samples exhibiting higher LIDT. The removal of more material during polishing significantly improved the LIDT of otherwise identical samples, indicating the importance of subsurface damage defects in the LIDT of ZGP.

  18. System and method for liquid silicon containment

    DOE Patents [OSTI]

    Cliber, James A; Clark, Roger F; Stoddard, Nathan G; Von Dollen, Paul

    2013-05-28T23:59:59.000Z

    This invention relates to a system and a method for liquid silicon containment, such as during the casting of high purity silicon used in solar cells or solar modules. The containment apparatus includes a shielding member adapted to prevent breaching molten silicon from contacting structural elements or cooling elements of a casting device, and a volume adapted to hold a quantity of breaching molten silicon with the volume formed by a bottom and one or more sides.

  19. System and method for liquid silicon containment

    SciTech Connect (OSTI)

    Cliber, James A; Clark, Roger F; Stoddard, Nathan G; Von Dollen, Paul

    2014-06-03T23:59:59.000Z

    This invention relates to a system and a method for liquid silicon containment, such as during the casting of high purity silicon used in solar cells or solar modules. The containment apparatus includes a shielding ember adapted to prevent breaching molten silicon from contacting structural elements or cooling elements of a casting device, and a volume adapted to hold a quantity of breaching molten silicon with the volume formed by a bottom and one or more sides.

  20. Metal organic chemical vapor deposition of 111-v compounds on silicon

    DOE Patents [OSTI]

    Vernon, Stanley M. (Wellesley, MA)

    1986-01-01T23:59:59.000Z

    Expitaxial composite comprising thin films of a Group III-V compound semiconductor such as gallium arsenide (GaAs) or gallium aluminum arsenide (GaAlAs) on single crystal silicon substrates are disclosed. Also disclosed is a process for manufacturing, by chemical deposition from the vapor phase, epitaxial composites as above described, and to semiconductor devices based on such epitaxial composites. The composites have particular utility for use in making light sensitive solid state solar cells.

  1. The Single Crystal Diffractometer

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 andThe MolecularPlaceThe RoadDavidofSequence

  2. Thermodynamic and transport properties of single-crystal Yb{sub 14}MnSb{sub 11}

    SciTech Connect (OSTI)

    Fisher, I.R.; Wiener, T.A.; Budko, S.L.; Canfield, P.C. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)] [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Chan, J.Y.; Kauzlarich, S.M. [Department of Chemistry, One Shields Avenue, University of California, Davis, California 95616 (United States)] [Department of Chemistry, One Shields Avenue, University of California, Davis, California 95616 (United States)

    1999-06-01T23:59:59.000Z

    Relatively large (up to 250 mg) single crystals of the intermetallic compound Yb{sub 14}MnSb{sub 11} have been prepared by a flux-growth technique. The results of thermodynamic and transport measurements of these samples are presented. The compound orders ferromagnetically at approximately T{sub C}=53{plus_minus}1K, with a magnetization consistent with the assignment Mn{sup 3+} (3d{sup 4}) and Yb{sup 2+} (4f{sup 14}). The Mn moments are local in nature, with the full effective and saturated moment of the Hund{close_quote}s rule spin-only ground state. The electrical resistivity has a metallic temperature dependence, with only a modest anisotropy. Room-temperature values of the resistivity are relatively high for an intermetallic compound: 1630{plus_minus}160 {mu}{Omega}cm and 1250{plus_minus}130 {mu}{Omega}cm for currents flowing approximately parallel and perpendicular to the {ital c} axis, respectively. There is a distinct loss of spin-disorder scattering in the resistivity at T{sub C}. From the heat capacity, a rough estimation of the magnetic entropy gives {Delta}S{sub M}{approx}12.1 J/mol K, the value in reasonable agreement with the expected {Delta}S{sub M}{approx}R ln 5 from the assignment of these moments. All of these data are consistent with a picture of Mn{sup 3+} local moments being coupled via conduction electrons. To this end, Yb{sub 14}MnSb{sub 11} appears to be analogous to local-moment rare-earth intermetallic compounds, and may point the way toward a class of 3d Kondo lattice compounds. {copyright} {ital 1999} {ital The American Physical Society}

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

    SciTech Connect (OSTI)

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

    2008-01-01T23:59:59.000Z

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

  4. High-pressure single-crystal X-ray diffraction of Tl{sub 2}SeO{sub 4}

    SciTech Connect (OSTI)

    Grzechnik, Andrzej [Departamento de Fisica de la Materia Condensada, Universidad del Pais Vasco, E-48080 Bilbao (Spain)], E-mail: andrzej.grzechnik@ehu.es; Breczewski, Tomasz; Friese, Karen [Departamento de Fisica de la Materia Condensada, Universidad del Pais Vasco, E-48080 Bilbao (Spain)

    2008-11-15T23:59:59.000Z

    The effect of pressure on the crystal structure of thallium selenate (Tl{sub 2}SeO{sub 4}) (Pmcn, Z=4), containing the Tl{sup +} cations with electron lone pairs, has been studied with single-crystal X-ray diffraction in a diamond anvil cell up to 3.64 GPa at room temperature. No phase transition has been observed. The compressibility data are fitted by a Murnaghan equation of state with the zero-pressure bulk modulus B{sub 0}=29(1) GPa and the unit-cell volume at ambient pressure V{sub 0}=529.6(8) A{sup 3} (B'=4.00). Tl{sub 2}SeO{sub 4} is the least compressible in the c direction, while the pressure-induced changes of the a and b lattice parameters are quite similar. These observations can be explained by different pressure effects on the nine- and 11-fold coordination polyhedra around the two non-equivalent Tl atoms. The SeO{sub 4}{sup 2-} tetrahedra are not rigid units and become more distorted. Their contribution to the compressibility is small. The effect of pressure on the isotypical oxide materials A{sub 2}TO{sub 4} with the {beta}-K{sub 2}SO{sub 4} structure is discussed. It appears that the presence of electron lone pairs on the Tl{sup +} cation does not seem to influence the compressibility of Tl{sub 2}SeO{sub 4}. - Graphical abstract: Pressure dependence of normalized lattice parameters and unit-cell volumes in Tl{sub 2}SeO{sub 4} (Pmcn, Z=4). The solid line is the Murnaghan equation of state.

  5. A systematic analysis of the spectra of the lanthanides doped into single crystal LaF/sub 3/

    SciTech Connect (OSTI)

    Carnall, W.T.; Goodman, G.L.; Rajnak, K.; Rana, R.S.

    1988-02-01T23:59:59.000Z

    The optical spectra of the lanthanides doped into single crystal LaF/sub 3/ have been interpreted in terms of transitions within 4f/sup N/ configurations. Energy-level calculations were based on a simultaneous diagonalization of the free-ion and crystal-field matrices using an approximate model with C/sub 2v/ site symmetry instead of the actual C/sub 2/ symmetry. Excellent correlations between experimental transition energies and the computed level structures were obtained; predicted levels are given for Pm/sup 3 +/. Previously unpublished experimental results for Nd/sup 3 +/ and Sm/sup 3 +/:LaF/sub 3/ are included in the tabulations. The spectroscopic data for each ion were analyzed independently, then the parameters of the effective-operator model were intercompared and systematic trends were identified. Since many of the 4f/sup N/ configurations extend well into the vacuum ultraviolet region, and thus beyond any presently available experimental observations, some of the free-ion (atomic) parameters were found to be only approximately defined by the accessible levels. However, the crystal-field parameters seem for the most part to be well established by fits to data at low energies. A new chart of the lanthanide ion 4f/sup N/ configuration energy level structures is presented. It was generated by including all of the computed crystal-field levels in the 0-50000 cm/sup -1/ range. In most cases, experimental analyses of individual ions extended to /approximately/40000 cm/sup /minus/1/. 94 refs., 23 figs., 10 tabs.

  6. Synthesis, structure, growth and characterization of a novel organic NLO single crystal: Morpholin-4-ium p-aminobenzoate

    SciTech Connect (OSTI)

    Shanmugam, G. [Department of Physics, Anna University of Technology Tiruchirappalli, Tiruchirappalli 620024 (India)] [Department of Physics, Anna University of Technology Tiruchirappalli, Tiruchirappalli 620024 (India); Ravi Kumar, K.; Sridhar, B. [X-ray Crystallography Division, Indian Institute of Chemical Technology, CSIR, Hyderabad 500007 (India)] [X-ray Crystallography Division, Indian Institute of Chemical Technology, CSIR, Hyderabad 500007 (India); Brahadeeswaran, S., E-mail: sbrag67@yahoo.com [Department of Physics, Anna University of Technology Tiruchirappalli, Tiruchirappalli 620024 (India)

    2012-09-15T23:59:59.000Z

    Highlights: ? A new organic NLO crystal morpholin-4-ium p-aminobenzoate has been grown for the first time. ? The structure is reported for the first time in the literature. ? Thermal, optical and SHG studies suggest its suitability for various NLO applications. -- Abstract: The title compound, morpholin-4-ium p-aminobenzoate (MPABA)(C{sub 4}H{sub 10}NO{sup +},C{sub 7}H{sub 6}NO{sub 2}{sup ?}), has been synthesized for the first time by the addition of morpholine with 4-aminobenzoic acid in equi-molar ratio and good quality single crystals have been grown by solution growth technique using methanol as a solvent. The molecular structure of the compound was solved and refined by Direct Methods using SHELXS97 and full-matrix least-squares technique using SHELXL97, respectively. MPABA crystallizes in a monoclinic system with unit cell parameters, a = 5.948(5) ?, b = 18.033(4) ?, c = 10.577(5) ?, ? = 90.40(1)° and non-centrosymmetric space group Cc. The experimentally measured density and chemical compositions were found to be in good agreement with the theoretical values. The phases and functional groups of MPABA have been identified and confirmed through powder X-ray diffraction and Fourier transform infrared (FTIR) studies, respectively. The thermal stability and decomposition details were studied through TG/DTA thermograms. The UV–visible transmission spectra were recorded for the grown crystal and its NLO characteristic was explored by powder second harmonic generation (SHG) studies.

  7. Shock wave compression of hexagonal-close-packed metal single crystals: Time-dependent, anisotropic elastic-plastic response of beryllium

    SciTech Connect (OSTI)

    Winey, J. M.; Gupta, Y. M. [Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164 (United States)

    2014-07-21T23:59:59.000Z

    Understanding and modeling the response of hcp metals to high stress impulsive loading is challenging because the lower crystal symmetry, compared to cubic metals, results in a significantly more complex material response. To gain insight into the inelastic deformation of hcp metals subjected to high dynamic stresses, shock wave compression of single crystals provides a useful approach because different inelastic deformation mechanisms can be examined selectively by shock compression along different crystal orientations. As a representative example, we report, here, on wave propagation simulations for beryllium (Be) single crystals shocked along the c-axis, a-axis, and several low-symmetry directions to peak stresses reaching 7?GPa. The simulations utilized a time-dependent, anisotropic material model that incorporated dislocation dynamics, deformation twinning, and shear cracking based descriptions of inelastic deformation. The simulation results showed good overall agreement with measured wave profiles for all the different crystal orientations examined [Pope and Johnson, J. Appl. Phys. 46, 720 (1975)], including features arising from wave mode coupling due to the highly anisotropic inelastic response of Be. This good agreement demonstrates that the measured profiles can be understood in terms of dislocation slip along basal, prismatic, and pyramidal planes, together with deformation twinning along (101{sup ¯}2) planes. Our results show that the response of shocked Be single crystals involves the simultaneous operation of multiple, distinct inelastic deformation mechanisms for all orientations except the c-axis. For shocked c-axis Be, the measured wave profiles do not provide good discrimination between pyramidal slip and other inelastic deformation mechanisms, such as shear cracking. The findings presented here provide insight into the complex inelastic deformation response of shocked Be single crystals and are expected to be useful for other hcp crystals. More broadly, the present work demonstrates the potential of shock wave propagation along low-symmetry directions to examine, and discriminate between, different inelastic deformation mechanisms in crystalline solids.

  8. Measurement of the Young's modulus and internal friction of single crystal and polycrystalline copper, and copper-graphite composites as a function of temperature and orientation

    E-Print Network [OSTI]

    Wickstrom, Steven Norman

    1988-01-01T23:59:59.000Z

    MEASUREMENT OF THE YOUNG'S MODULUS AND INTERNAL FRICTION OF SINGLE CRYSTAL AND POLYCRYSTALLINE COPPER, AND COPPER- GRAPHITE COMPOSITES AS A FUNCTION OF TEMPERATURE AND ORIENTATION A Thesis by S teven Norman Wicks trom Submitted... AND POLYCRYSTALLINE COPPER, AND COPPER- GRAPHITE COMPOSITES AS A FUNCTION OF TEMPERATURE AND ORIENTATION A Thesis by Steven Norman Wickstrom Approved as to style and content by: A(J ~a Alan Wolfenden (Chairman of Committee) Don E. Bray (Member) Donald G...

  9. Epitaxial TiN(001) wetting layer for growth of thin single-crystal Cu(001) J. S. Chawla, X. Y. Zhang, and D. Galla)

    E-Print Network [OSTI]

    Gall, Daniel

    Epitaxial TiN(001) wetting layer for growth of thin single-crystal Cu(001) J. S. Chawla, X. Y.5-nm-thick TiN(001) buffer layer. X-ray diffraction and reflection indicate that the TiN(001) surface continuous Cu layer on MgO. The wet- ting of Cu on TiN is expected to be better, due to the surface energy

  10. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO{sub 4} single crystals near the intrinsic luminescence peak

    SciTech Connect (OSTI)

    Buzanov, O. A., E-mail: fedorov-metrology@yandex.ru [OAO Fomos-Materials (Russian Federation); Kanevskii, V. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Kornoukhov, V. N. [OAO Fomos-Materials (Russian Federation)] [OAO Fomos-Materials (Russian Federation); Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15T23:59:59.000Z

    The optical and spectral characteristics of isotopically enriched Czochralski-grown {sup 40}Ca{sup 100}MoO{sub 4} single crystals have been investigated. This material is promising for detecting double neutrinoless {beta} decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  11. Development of large-area monolithically integrated silicon-film photovoltaic modules. Annual subcontract report, 1 May 1991--15 November 1991

    SciTech Connect (OSTI)

    Rand, J.A.; Bacon, C.; Cotter, J.E.; Lampros, T.H.; Ingram, A.E.; Ruffins, T.R.; Hall, R.B.; Barnett, A.M. [AstroPower, Inc., Newark, DE (United States)

    1992-07-01T23:59:59.000Z

    This report describes work to develop Silicon-Film Product III into a low-cost, stable device for large-scale terrestrial power applications. The Product III structure is a thin (< 100 {mu}m) polycrystalline silicon layer on a non-conductive supporting ceramic substrate. The presence of the substrate allows cells to be isolated and in interconnected monolithically in various series/parallel configurations. The long-term goal for the product is efficiencies over 18% on areas greater than 1200 cm{sup 2}. The high efficiency is made possible through the benefits of using polycrystalline thin silicon incorporated into a light-trapping structure with a passivated back surface. Short-term goals focused on the development of large-area ceramics, a monolithic interconnection process, and 100 cm{sup 2} solar cells. Critical elements of the monolithically integrated device were developed, and an insulating ceramic substrate was developed and tested. A monolithic interconnection process was developed that will isolate and interconnect individual cells on the ceramic surface. Production-based, low-cost process steps were used, and the process was verified using free-standing silicon wafers to achieve an open-circuit voltage (V{sub oc}) of 8.25 V over a 17-element string. The overall efficiency of the silicon-film materials was limited to 6% by impurities. Improved processing and feedstock materials are under investigation.

  12. Powerful, Efficient Electric Vehicle Chargers: Low-Cost, Highly-Integrated Silicon Carbide (SiC) Multichip Power Modules (MCPMs) for Plug-In Hybrid Electric

    SciTech Connect (OSTI)

    None

    2010-09-14T23:59:59.000Z

    ADEPT Project: Currently, charging the battery of an electric vehicle (EV) is a time-consuming process because chargers can only draw about as much power from the grid as a hair dryer. APEI is developing an EV charger that can draw as much power as a clothes dryer, which would drastically speed up charging time. APEI's charger uses silicon carbide (SiC)-based power transistors. These transistors control the electrical energy flowing through the charger's circuits more effectively and efficiently than traditional transistors made of straight silicon. The SiC-based transistors also require less cooling, enabling APEI to create EV chargers that are 10 times smaller than existing chargers.

  13. Electronic stiffness of a superconducting niobium nitride single crystal under pressure Xiao-Jia Chen, Viktor V. Struzhkin, Zhigang Wu, Ronald E. Cohen, Simon Kung,* Ho-kwang Mao, and Russell J. Hemley

    E-Print Network [OSTI]

    Wu, Zhigang

    Electronic stiffness of a superconducting niobium nitride single crystal under pressure Xiao report a quantitative study of pressure effects on the superconducting transition temperature Tc transition temperatures Tc's of materials, pur- suing new classes of superconductors and shedding light

  14. Abstract. --The density matrix formalism is applied to the interpretation of Mossbauer spectra of single crystals of K3Fe(CN) taken with polarized y-radiation to find the average electric hyper-

    E-Print Network [OSTI]

    Boyer, Edmond

    of single crystals of K3Fe(CN)« taken with polarized y-radiation to find the average electric hyper- fine also. By a properly chosen set of measurements sites. A MOSSBAUER STUDY OF THE ELECTRIC HYPERFINE

  15. Floating Silicon Method

    SciTech Connect (OSTI)

    Kellerman, Peter

    2013-12-21T23:59:59.000Z

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  16. Line Broadening and Decoherence of Electron Spins in Phosphorus-Doped Silicon Due to Environmental 29^Si Nuclear Spins

    E-Print Network [OSTI]

    Eisuke Abe; Akira Fujimoto; Junichi Isoya; Satoshi Yamasaki; Kohei M. Itoh

    2005-12-16T23:59:59.000Z

    Phosphorus-doped silicon single crystals with 0.19 % effect of environmental 29^Si nuclear spins on the donor electron spin is systematically studied. The linewidth as a function of f shows a good agreement with theoretical analysis. We also report the phase memory time T_M of the donor electron spin dependent on both f and the crystal axis relative to the external magnetic field.

  17. Magnetic structure of Sr{sub 2}Fe{sub 2}O{sub 5} brownmillerite by single-crystal Mössbauer spectroscopy

    SciTech Connect (OSTI)

    Waerenborgh, J.C. [UCQR, IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, CFMC-UL, Estrada Nacional 10, 2686-953 Sacavém (Portugal); Tsipis, E.V. [UCQR, IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, CFMC-UL, Estrada Nacional 10, 2686-953 Sacavém (Portugal); Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Auckett, J.E.; Ling, C.D. [School of Chemistry, The University of Sydney, Sydney 2006 (Australia); Kharton, V.V., E-mail: kharton@ua.pt [Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Institute of Solid State Physics RAS, Chernogolovka 142432, Moscow Region (Russian Federation)

    2013-09-15T23:59:59.000Z

    In order to determine orientation of the Fe{sup 3+} magnetic moments and electric field gradient (efg) axes in the brownmillerite-type strontium ferrite structure for both iron sublattices where the efg tensor is not axially symmetric, the Mössbauer spectra of powdered and oriented single-crystal Sr{sub 2}Fe{sub 2}O{sub 5} were analyzed by solving the complete Hamiltonian for hyperfine interactions in the excited and ground states of the {sup 57}Fe nuclei. The magnetic moments of both octahedrally and tetrahedrally coordinated iron cations lie on the ac-plane of the orthorhombic unit cell and are parallel to the shortest c-axis, whilst the main efg axes are parallel to the longest crystallographic axis, b. This orientation is similar to that in Ca{sub 2}Fe{sub 2}O{sub 5}, in spite of the structural differences of strontium and calcium ferrite brownmillerites at low temperatures. - Graphical abstract: Mössbauer spectra of powdered and oriented single-crystal Sr{sub 2}Fe{sub 2}O{sub 5}, analyzed by solving the complete Hamiltonian for hyperfine interactions in the excited and ground states of the {sup 57}Fe nuclei, show that the magnetic moments of both octahedrally and tetrahedrally coordinated iron cations are parallel to the shortest c-axis of the orthorhombic brownmillerite unit cell . Display Omitted - Highlights: • Single-crystal Mössbauer spectroscopy is used to study magnetic structure of Sr{sub 2}Fe{sub 2}O{sub 5}. • Complete Hamiltonian for hyperfine interactions in excited and ground states was solved. • Fe{sup 3+} magnetic moments are parallel to the shortest crystallographic axis c. • The orientation of nuclear electric field gradient is similar to that in Ca{sub 2}Fe{sub 2}O{sub 5}.

  18. Dissolution-induced surface modifications and permeability changes associated with fluid flow through an abraded saw-cut in single crystal quartz

    E-Print Network [OSTI]

    Bowman, James Albert

    1992-01-01T23:59:59.000Z

    -CUT IN SINGLE CRYSTAL QUARTZ A Thesis by JAMES ALBERT BOWMAN, JR. Approved as to style and content by: Brann Jo on (Co-Chairman ommittee) Thomas T. Tieh (Co-Chairman of Committee) Andrew )ash (Member) Frank Dale Morgan (Member) John H. pang (Head...-axis z-plane Figure 4. Geometrv and crystallograpiuc orienration of negative crystal developed on m-plane of quartz dissoived in a weak basic solunon. After Gratz and others (1990). 12 Profiles F F S- Slow Dissolving Plane F-Fast Dissolvmg Plane l...

  19. Modifications of the surface properties of metals by oxide overlayers: 1, Oxidized zirconium deposited on the Pt(100) single crystal surface

    SciTech Connect (OSTI)

    Bardi, U.; Ross, P.N.

    1986-06-01T23:59:59.000Z

    Metallic zirconium was deposited on a single crystal Pt(100) surface by thermal evaporation in UHV conditions. The deposit was oxidized by exposure to oxygen immediately after deposition. Oxidized zirconium was found to grow on the platinum ace by the layer-by-layer mechanism. The adsorption of carbon monoxide on the surface was studied as a function of the zirconium coverage. The results show that oxidized zirconium forms a chemically inert layer which blocks the adsorptive sites of the underlying platinum substrate. The properties of the free Pt surface were unaffected by the presence of the oxidized zirconium layer.

  20. Rabi Waves and Peculiarities of Raman Scattering in Carbon Nanotubes, Produced by High Energy Ion Beam Modification of Diamond Single Crystals

    E-Print Network [OSTI]

    Dmitry Yearchuck; Alla Dovlatova

    2011-03-06T23:59:59.000Z

    QED-model for multichain coupled qubit system, proposed in \\cite{Part1}, was confirmed by Raman scattering studies of carbon zigzag-shaped nanotubes, produced by high energy ion beam modification of natural diamond single crystals. New quantum optics phenomenon - Rabi waves - has been experimentally identified for the first time. Raman spectra in perfect quasi-1D carbon nanotubes are quite different in comparison with well known Raman spectra in 2D carbon nanotubes of larger diameter. They characterized by vibronic mode of Su-Schriffer-Heeger $\\sigma$-polaron lattice and its revival part in frequency representation, which is the consequence of Rabi wave packet formation.

  1. Scanning Josephson Tunneling Microscopy of Single Crystal Bi2Sr2CaCu2O8+delta with a Conventional Superconducting Tip

    SciTech Connect (OSTI)

    Kimura, H.; Barber Jr., R. P.; Ono, S.; Ando, Yoichi; Dynes, Robert C.

    2009-10-28T23:59:59.000Z

    We have performed both Josephson and quasiparticle tunneling in vacuum tunnel junctions formed between a conventional superconducting scanning tunneling microscope tip and overdoped Bi2Sr2CaCu2O8+ single crystals. A Josephson current is observed with a peak centered at a small finite voltage due to the thermal-fluctuation-dominated superconducting phase dynamics. Josephson measurements at different surface locations yield local values for the Josephson ICRN product. Corresponding energy gap measurements were also performed and a surprising inverse correlation was observed between the local ICRN product and the local energy gap.

  2. Heterogeneous lithium niobate photonics on silicon substrates

    E-Print Network [OSTI]

    Fathpour, Sasan

    Heterogeneous lithium niobate photonics on silicon substrates Payam Rabiei,1,* Jichi Ma,1 Saeed-confined lithium niobate photonic devices and circuits on silicon substrates is reported based on wafer bonding high- performance lithium niobate microring optical resonators and Mach- Zehnder optical modulators

  3. Method for forming silicon on a glass substrate

    DOE Patents [OSTI]

    McCarthy, A.M.

    1995-03-07T23:59:59.000Z

    A method by which single-crystal silicon microelectronics may be fabricated on glass substrates at unconventionally low temperatures. This is achieved by fabricating a thin film of silicon on glass and subsequently forming the doped components by a short wavelength (excimer) laser doping procedure and conventional patterning techniques. This method may include introducing a heavily boron doped etch stop layer on a silicon wafer using an excimer laser, which permits good control of the etch stop layer removal process. This method additionally includes dramatically reducing the remaining surface roughness of the silicon thin films after etching in the fabrication of silicon on insulator wafers by scanning an excimer laser across the surface of the silicon thin film causing surface melting, whereby the surface tension of the melt causes smoothing of the surface during recrystallization. Applications for this method include those requiring a transparent or insulating substrate, such as display manufacturing. Other applications include sensors, actuators, optoelectronics, radiation hard and high temperature electronics. 15 figs.

  4. A Successful Synthesis of the CoCrFeNiAl{sub 0.3} Single-Crystal, High-Entropy Alloy by Bridgman Solidification

    SciTech Connect (OSTI)

    Ma, S. G.; Zhang, S. F.; Gao, M. C.; Liaw, P. K.; Zhang, Y.

    2013-12-01T23:59:59.000Z

    For the first time, a face-centered-cubic, single-crystal CoCrFeNiAl{sub 0.3} (designated as Al0.3), high-entropy alloy (HEA) was successfully synthesized by the Bridgman solidification (BS) method, at an extremely low withdrawal velocity through a constant temperature gradient, for which it underwent two BS steps. Specially, at the first BS step, the alloy sample underwent several morphological transitions accompanying the crystal growth from the melt. This microstructure evolves from as-cast dendrites, to equiaxed grains, and then to columnar crystals, and last to the single crystal. In particular, at the equiaxed-grain region, some visible annealing twins were observed, which indicates a low stacking fault energy of the Al0.3 alloy. Although a body-centered- cubic CoCrFeNiAl (Al1) HEA was also prepared under the same conditions, only a single columnar-crystal structure with instinctively preferential crystallographic orientations was obtained by the same procedure. A similar morphological transition from dendrites to equiaxed grains occurred at the equiaxed-grain region in Al1 alloy, but the annealing twins were not observed probably because a higher Al addition leads to a higher stacking fault energy for this alloy.

  5. Features of the charge-transport mechanism in layered Bi{sub 2}Te{sub 3} single crystals doped with chlorine and terbium

    SciTech Connect (OSTI)

    Abdullaev, N. A., E-mail: anadir@azintex.com; Abdullaev, N. M.; Aliguliyeva, H. V.; Kerimova, T. G.; Mehdiyev, G. S. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan); Nemov, S. A. [St. Petersburg State Polytechnic University (Russian Federation)

    2011-01-15T23:59:59.000Z

    The temperature dependences (T = 5-300 K) of the resistivity in the plane of layers and in the direction perpendicular to the layers, as well as the Hall effect and the magnetoresistance (H < 80 kOe, T = 0.5-4.2 K) in Bi{sub 2}Te{sub 3} single crystals doped with chlorine and terbium, are investigated. It is shown that the doping of Bi{sub 2}Te{sub 3} with terbium atoms results in p-type conductivity and in increasing hole concentration. The doping of Bi{sub 2}Te{sub 3} with chlorine atoms modifies also the character of its conductivity instead of changing only the type from p to n. In the temperature dependence of the resistivity in the direction perpendicular to layers, a portion arises with the activation conductivity caused by the hopping between localized states. The charge-transport mechanism in Bi{sub 2}Te{sub 3} single crystals doped with chlorine is proposed.

  6. Efficient Electro-Optical Modulation Based on Indium Tin Oxide

    E-Print Network [OSTI]

    Shi, Kaifeng

    2015-01-01T23:59:59.000Z

    We experimentally demonstrate several electro-optical modulators based on transparent conducting oxides. Our previous work demonstrated the modulator structure on glass substrate with broadband bias polarity-dependent modulation. Further exploration shows similar modulation effect of the modulator on quartz and silicon substrate.

  7. Surface structure of coadsorbed benzene and carbon monoxide on the rhodium(111) single crystal analyzed with low-energy electron diffraction intensities

    SciTech Connect (OSTI)

    Van Hove, M.A.; Lin, R.F.; Somorjai, G.A.

    1986-05-14T23:59:59.000Z

    The first structural analysis of a molecular coadsorbate system is presented. Mutual reordering and site shifting are found to occur for benzene and CO coadsorbed in a (/sub 13//sup 31/) lattice on Rh(111). This low-energy electron diffraction (LEED) intensity analysis yields the first confirmed hollow-site adsorption of CO on a single-crystal metal surface, with a C-O bond length expanded by 0.06 +/- 0.05 A from the gas phase. The flat-lying benzene is found centered over hcp-type hollow sites with a strong Kekule-type distortion: C-C bond lengths alternate between 1.33 +/- 0.15 A (hydrogen positions were not determined). This suggests the possibility of a 1,3,5-cyclohexatriene species being formed. The Rh-C bond length is 2.35 +/- 0.05 A for benzene and 2.16 +/- 0.04 A for CO.

  8. Effect of electron irradiation on superconductivity in single crystals of Ba(Fe1-xRux)2As2 (x=0.24)

    SciTech Connect (OSTI)

    Prozorov, Ruslan [Ames Laboratory; Konczykowski, M [Laboratoire des Solides Irradies; Tanatar, Makariy A. [Ames Laboratory; Thaler, Alexander [Ames Laboratory; Budko, Serguei L [Ames Laboratory; Canfield, Paul C [Ames Laboratory; Mishra, V [Argonne National Laboratory; Hirschfeld, P J [University of Florida

    2014-11-01T23:59:59.000Z

    A single crystal of isovalently substituted Ba(Fe1?xRux)2As2 (x=0.24) is sequentially irradiated with 2.5 MeV electrons up to a maximum dose of 2.1×1019 e?/cm2. The electrical resistivity is measured in situ at T=22??K during the irradiation and ex situ as a function of temperature between subsequent irradiation runs. Upon irradiation, the superconducting transition temperature Tc decreases and the residual resistivity ?0 increases. We find that electron irradiation leads to the fastest suppression of Tc compared to other types of artificially introduced disorder, probably due to the strong short-range potential of the pointlike irradiation defects. A more detailed analysis within a multiband scenario with variable scattering potential strength shows that the observed Tc versus ?0 is fully compatible with s± pairing, in contrast to earlier claims that this model leads to a too rapid suppression of Tc with scattering.

  9. Infrared phonon modes in multiferroic single-crystal FeTe2O5Br

    SciTech Connect (OSTI)

    Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

    2013-06-01T23:59:59.000Z

    Reflection and transmission as a function of temperature (7–300 K and 5–300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

  10. Bridgman Growth of Large SrI2:Eu2+ Single Crystals: A High-performance Scintillator for Radiation Detection Applications

    SciTech Connect (OSTI)

    Boatner, Lynn A [ORNL; Ramey, Joanne Oxendine [ORNL; Kolopus, James A [ORNL; Hawrami, Rastgo [Radiation Monitoring Devices, Watertown, MA; Higgins, William [Radiation Monitoring Devices, Watertown, MA; Van Loef, Edgar [Radiation Monitoring Devices, Watertown, MA; Glodo, J. [Radiation Monitoring Devices, Watertown, MA; Shah, Kanai [Radiation Monitoring Devices, Watertown, MA; Bhattacharya, P. [Fisk University, Nashville, TN; Tupitsyn, E [Fisk University, Nashville, TN; Groza, Michael [Fisk University, Nashville, TN; Burger, Arnold [Fisk University, Nashville, TN

    2013-01-01T23:59:59.000Z

    Single-crystal strontium iodide (SrI2) doped with relatively high levels (e.g., 3 - 6 %) of Eu2+ exhibits characteristics that make this material superior, in a number of respects, to other scintillators that are currently used for radiation detection. Specifically, SrI2:Eu2+ has a light yield that is significantly higher than LaBr3:Ce3+ -a currently employed commercial high-performance scintillator. Additionally, SrI2:Eu2+ is characterized by an energy resolution as high as 2.6% at the 137Cs gamma-ray energy of 662 keV, and there is no radioactive component in SrI2:Eu2+ - unlike LaBr3:Ce3+ that contains 138La. The Ce3+-doped LaBr3 decay time is, however, faster (30 nsec) than the 1.2 sec decay time of SrI2:Eu2+. Due to the relatively low melting point of strontium iodide (~515 oC), crystal growth can be carried out in quartz crucibles by the vertical Bridgman technique. Materials-processing and crystal-growth techniques that are specific to the Bridgman growth of europium-doped strontium iodide scintillators are described here. These techniques include the use of a porous quartz frit to physically filter the molten salt from a quartz antechamber into the Bridgman growth crucible and the use of a bent or bulb grain selector design to suppress multiple grain growth. Single crystals of SrI2:Eu2+ scintillators with good optical quality and scintillation characteristics have been grown in sizes up to 5.0 cm in diameter by applying these techniques. Other aspects of the SrI2:Eu2+ crystal-growth methods and of the still unresolved crystal-growth issues are described here.

  11. Synthesis, single-crystal structure, and optical absorption of Rb{sub 2}Th{sub 7}Se{sub 15}

    SciTech Connect (OSTI)

    Koscielski, Lukasz A.; Pozzi, Eric A.; Van Duyne, Richard P.; Ibers, James A., E-mail: ibers@chem.northwestern.edu

    2013-09-15T23:59:59.000Z

    The compound Rb{sub 2}Th{sub 7}Se{sub 15} has been synthesized by the solid-state reaction at 1273 K of Th, Rb{sub 2}Se{sub 3}, Se, and Ge, and its structure has been determined by single-crystal X-ray diffraction methods. Red crystals of Rb{sub 2}Th{sub 7}Se{sub 15} crystallize at 100(2) K with four formula units in a new structure type in the monoclinic space group C{sub 2h}{sup 5}?P2{sub 1}/c. The structure is three-dimensional and comprises Rb and Th atoms coordinated by Se atoms to form nine-, eight-, and seven-coordinate polyhedra. Infinite channels that contain Rb atoms are present. Crystals of Rb{sub 2}Th{sub 7}Se{sub 15} are red in color; an indirect band gap of 1.83 eV was derived from single-crystal optical measurements. - Graphical abstract: Structure of Rb{sub 2}Th{sub 7}Se{sub 15} viewed down the b-axis. Display Omitted - Highlights: • The new compound Rb{sub 2}Th{sub 7}Se{sub 15} was synthesized at 1273 K from the elements in the presence of Ge. • The structures of the two known Rb/Th/Se compounds, RbTh{sub 2}Se{sub 6} and Rb{sub 2}Th{sub 7}Se{sub 15}, differ markedly. • Optical measurements establish the band gap of Rb{sub 2}Th{sub 7}Se{sub 15} to be indirect with a value of 1.83 eV.

  12. Combined Charge Carrier Transport and Photoelectrochemical Characterization of BiVO4 Single Crystals: Intrinsic Behavior of a Complex Metal Oxide

    SciTech Connect (OSTI)

    Rettie, Alexander J.; Lee, Heung Chan; Marshall, Luke G.; Lin, Jung-Fu; Capen, Cigdem; Lindemuth, Jeffrey; McCloy, John S.; Zhou, Jianshi; Bard, Allen J.; Mullins, C. Buddie

    2013-07-08T23:59:59.000Z

    ABSTRACT: Bismuth vanadate (BiVO4) is a promising photoelectrode material for the oxidation of water, but fundamental studies of this material are lacking. To address this, we report electrical and photoelectrochemical (PEC) properties of BiVO4 single crystals (undoped, 0.6% Mo and 0.3% W:BiVO4) grown using the floating zone technique. We demonstrate that a small polaron hopping conduction mechanism dominates from 250-400 K, transitioning to a variable range hopping mechanism at lower temperatures. An anisotropy ratio of ~3 was observed along the c-axis, attributed to the layered structure of BiVO4. Measurements of the AC field Hall effect yielded an electron mobility of ~0.2 cm2 V-1 s-1 for Mo and W:BiVO4 at 300 K. By application of the Gärtner model, a hole diffusion length of ~140 nm was estimated. As a result of low carrier mobility, attempts to measure the DC Hall effect were unsuccessful. Analyses of the Raman spectra showed that Mo and W substituted for V and acted as donor impurities. Mott-Schottky analysis of electrodes with the (001) face exposed yielded a flat band potential of 0.03-0.08 V vs. RHE, while incident photon conversion efficiency tests showed that the dark coloration of the doped single crystals did not result in additional photocurrent. Comparison of these intrinsic properties to other metal oxides for PEC applications gives valuable insight into this material as a photoanode.

  13. Search for WW and WZ production in lepton, neutrino plus jets final states at CDF Run II and Silicon module production and detector control system for the ATLAS SemiConductor Tracker

    SciTech Connect (OSTI)

    Sfyrla, Anna; /Geneva U.

    2008-03-01T23:59:59.000Z

    In the first part of this work, we present a search for WW and WZ production in charged lepton, neutrino plus jets final states produced in p{bar p} collisions with {radical}s = 1.96 TeV at the Fermilab Tevatron, using 1.2 fb{sup -1} of data accumulated with the CDF II detector. This channel is yet to be observed in hadron colliders due to the large singleWplus jets background. However, this decay mode has a much larger branching fraction than the cleaner fully leptonic mode making it more sensitive to anomalous triple gauge couplings that manifest themselves at higher transverse W momentum. Because the final state is topologically similar to associated production of a Higgs boson with a W, the techniques developed in this analysis are also applicable in that search. An Artificial Neural Network has been used for the event selection optimization. The theoretical prediction for the cross section is {sigma}{sub WW/WZ}{sup theory} x Br(W {yields} {ell}{nu}; W/Z {yields} jj) = 2.09 {+-} 0.14 pb. They measured N{sub Signal} = 410 {+-} 212(stat) {+-} 102(sys) signal events that correspond to a cross section {sigma}{sub WW/WZ} x Br(W {yields} {ell}{nu}; W/Z {yields} jj) = 1.47 {+-} 0.77(stat) {+-} 0.38(sys) pb. The 95% CL upper limit to the cross section is estimated to be {sigma} x Br(W {yields} {ell}{nu}; W/Z {yields} jj) < 2.88 pb. The second part of the present work is technical and concerns the ATLAS SemiConductor Tracker (SCT) assembly phase. Although technical, the work in the SCT assembly phase is of prime importance for the good performance of the detector during data taking. The production at the University of Geneva of approximately one third of the silicon microstrip end-cap modules is presented. This collaborative effort of the university of Geneva group that lasted two years, resulted in 655 produced modules, 97% of which were good modules, constructed within the mechanical and electrical specifications and delivered in the SCT collaboration for assembly on the end-cap disks. The SCT end-caps and barrels consist of 4088 silicon modules, with a total of 6.3 million readout channels. The coherent and safe operation of the SCT during commissioning and subsequent operation is the essential task of the Detector Control System (DCS). The main building blocks of the DCS are the cooling system, the power supplies and the environmental system. The DCS has been initially developed for the SCT assembly phase and this system is described in the present work. Particular emphasis is given in the environmental hardware and software components, that were my major contributions. Results from the DCS testing during the assembly phase are also reported.

  14. Amorphous Silicon

    Broader source: Energy.gov [DOE]

    DOE has a proven track record of funding successes in amorphous silicon (a-Si)research. A list of current projects, summary of the benefits, and discussion on the production and manufacturing of...

  15. Silicon nitride/silicon carbide composite powders

    DOE Patents [OSTI]

    Dunmead, Stephen D. (Midland, MI); Weimer, Alan W. (Midland, MI); Carroll, Daniel F. (Midland, MI); Eisman, Glenn A. (Midland, MI); Cochran, Gene A. (Midland, MI); Susnitzky, David W. (Midland, MI); Beaman, Donald R. (Midland, MI); Nilsen, Kevin J. (Midland, MI)

    1996-06-11T23:59:59.000Z

    Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

  16. Nonlinear-optical and structural properties of nanocrystalline silicon carbide films

    SciTech Connect (OSTI)

    Brodyn, M. S.; Volkov, V. I., E-mail: volkov@iop.kiev.ua; Lyakhovetskii, V. R.; Rudenko, V. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine); Puzilkov, V. M.; Semenov, A. V. [National Academy of Sciences of Ukraine, Institute of Monocrystals (Ukraine)

    2012-02-15T23:59:59.000Z

    The aim of this study is to investigate the nonlinearity of refraction in nanostructured silicon carbide films depending on their structural features (synthesis conditions for such films, substrate temperature during their deposition, concentration of the crystalline phase in the film, Si/C ratio of atomic concentrations in the film, and size of SiC nanocrystals formed in the film). The corresponding dependences are obtained, as well as the values of nonlinear-optical third-order susceptibility {chi}{sup (3)}({omega}; {omega}, -{omega}, {omega}) for various silicon polytypes (3C, 21R, and 27R) which exceed the value of {chi}{sup (3)} in bulk silicon carbide single crystals by four orders of magnitude.

  17. Seventh workshop on the role of impurities and defects in silicon device processing

    SciTech Connect (OSTI)

    NONE

    1997-08-01T23:59:59.000Z

    This workshop is the latest in a series which has looked at technological issues related to the commercial development and success of silicon based photovoltaic (PV) modules. PV modules based on silicon are the most common at present, but face pressure from other technologies in terms of cell performance and cell cost. This workshop addresses a problem which is a factor in the production costs of silicon based PV modules.

  18. Structurally-driven metal-insulator transition in Ca{sub 2}Ru{sub 1-x}Cr{sub x}O{sub 4} (0{<=}x<0.14): A single crystal X-ray diffraction study

    SciTech Connect (OSTI)

    Qi, T.F., E-mail: tqi2@uky.ed [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Ge, M. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); High Magnetic Field Laboratory, University of Science and Technology of China, Hefei, Anhui 230026 (China); Korneta, O.B. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Parkin, S. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Chemistry, University of Kentucky, Lexington, KY 40506 (United States); De Long, L.E.; Cao, G. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)

    2011-04-15T23:59:59.000Z

    Correlation between structure and transport properties are investigated in high-quality single-crystals of Ca{sub 2}Ru{sub 1-x}Cr{sub x}O{sub 4} with 0single crystal X-ray diffraction and by electronic studies. The parent compound was known to exhibit an intriguing first-order structurally driven metal-insulator (MI) transition at 357 K. Upon chromium doping on the ruthenium site, the metal-insulator transition temperature (T{sub MI}) was drastically reduced, and is related to the competition between structural changes that occur upon Cr doping and with decreasing temperature. A strong suppression of structural distortions with increasing Cr substitution was identified. No clear T{sub MI} can be observed when x>13.5% and the system behaves as an insulator. Such a large, sharp metal-insulator transition and tuneable transition temperature may have potential applications in electronic devices. -- Graphical abstract: The metal-insulator transition temperature (T{sub MI}) was drastically reduced by Cr doping, and is closely related to the distortion of structure. Display Omitted Research highlights: {yields} The metal-insulator transition temperature (T{sub MI}) was drastically reduced by doping Cr into Ca{sub 2}RuO{sub 4} single crystal. {yields} Detailed single crystal structural analysis provided important insight into this structurally-driven metal-insulator transition. {yields} Negative Volume Thermal Expansion (NVTE) was observed with increasing temperature.

  19. Reciprocal space analysis of the microstructure of luminescent and nonluminescent porous silicon films

    SciTech Connect (OSTI)

    Lee, S.R.; Barbour, J.C.; Medernach, J.W.; Stevenson, J.O.; Custer, J.S.

    1994-12-31T23:59:59.000Z

    The microstructure of anodically prepared porous silicon films was determined using a novel X-ray diffraction technique. This technique uses double-crystal diffractometry combined with position-sensitive X- ray detection to efficiently and quantitatively image the reciprocal space structure of crystalline materials. Reciprocal space analysis of newly prepared, as well as aged, p{sup {minus}} porous silicon films showed that these films exhibit a very broad range of crystallinity. This material appears to range in structure from a strained, single-crystal, sponge-like material exhibiting long-range coherency to isolated, dilated nanocrystals embedded in an amorphous matrix. Reciprocal space analysis of n{sup +} and p{sup +} porous silicon showed these materials are strained single-crystals with a spatially-correlated array of vertical pores. The vertical pores in these crystals may be surrounded by nanoporous or nanocrystalline domains as small as a few nm in size which produce diffuse diffraction indicating their presence. The photoluminescence of these films was examined using 488 nm Ar laser excitation in order to search for possible correlations between photoluminescent intensity and crystalline microstructure.

  20. Process Research of Polycrystalline Silicon Material (PROPSM). Quarterly report No. 1, November 8-December 31, 1983

    SciTech Connect (OSTI)

    Culik, J.S.

    1984-01-01T23:59:59.000Z

    Recent reported results of hydrogen-passivated polycrystalline silicon solar cells are summarized. Most of the studies have been performed on very small grain or short minority-carrier diffusion length silicon. Hydrogenated solar cells fabricated from this material appear to have effective minority-carrier diffusion lengths that are still not very long, as shown by the open-circuit voltages of passivated cells that are still significantly less than those of single-crystal solar cells. The short-circuit current of solar cells fabricated from large-grain cast polycrystalline silicon is nearly equivalent to that of single-crystal cells, which indicates long bulk minority-carrier diffusion length. However, the open-circuit voltage, which is sensitive to grain boundary recombination, is 20 to 40 mV less. The goal of this program is to minimize the variations in open-circuit voltage and fill-factor that are caused by structural defects by passivating these defects using a hydrogenation process.

  1. Electron spin coherence of phosphorus donors in silicon: Effect of environmental nuclei

    SciTech Connect (OSTI)

    Abe, Eisuke [Department of Materials, Oxford University, Parks Road, Oxford OX1 3PH (United Kingdom); School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522 (Japan); Tyryshkin, Alexei M.; Lyon, Stephen A. [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Tojo, Shinichi; Fujimoto, Akira; Itoh, Kohei M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522 (Japan); Morton, John J. L. [Department of Materials, Oxford University, Parks Road, Oxford OX1 3PH (United Kingdom); Clarendon Laboratory, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom); Witzel, Wayne M. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Ager, Joel W. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Haller, Eugene E. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Isoya, Junichi [Graduate School of Library, Information and Media Studies, University of Tsukuba, 1-2 Kasuga, 305-8550 (Japan); Thewalt, Mike L. W. [Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada)

    2010-09-15T23:59:59.000Z

    We report electron paramagnetic resonance (EPR) experiments of phosphorus donors in isotopically controlled silicon single crystals. By varying the concentration of the {sup 29}Si isotope, f, from 0.075% to 99.2%, we systematically study the effect of the environmental nuclear spins on the donor-electron spin. We find excellent agreement between experiment and theory for decoherence times due to nuclear-induced spectral diffusion, clarifying that the nuclear-induced decoherence is dominant in the range of f studied. We also observe that the EPR linewidth shows a transition from the square-root dependence to the linear dependence on f, in agreement with theoretical predictions.

  2. Single-crystal-like NiO colloidal nanocrystal-aggregated microspheres with mesoporous structure: Synthesis and enhanced electrochemistry, photocatalysis and water treatment properties

    SciTech Connect (OSTI)

    Suo, Zhirong [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); Dong, Xiaonan [School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi’an 710021 (China); Liu, Hui, E-mail: liuhui@sust.edu.cn [School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi’an 710021 (China)

    2013-10-15T23:59:59.000Z

    A new microwave-assisted hydrothermal synthetic route based on the self-assembly and subsequently controlled thermal decomposition process is proposed to fabricate nickel oxide colloidal nanocrystal aggregated microspheres (CNAMs) with mesoporous structure. XRD, EDS, SEM, TEM. FTIR, and N{sub 2} adsorption and desorption isotherm techniques are employed for morphology and structure characterizations. The as-prepared nickel oxide CNAMs, which has a high surface area (234 m{sup 2}/g) with narrow pore distribution at around 3.25 nm, are composed of numerous hexagonal mesoporous nanocrystals of approximately 50–60 nm in size, and present a single-crystal-like characteristic. The experimental results also demonstrated that the CNAMs showed outstanding performance in electrochemistry, photocatalysis and waste water treatment due to their special hierarchical and mesoporous structure, presenting the promising candidate for catalysis and catalysis support materials. - Graphical abstract: CNAMs with mesoporous structure synthesized via a simple microwave-assisted hydrothermal method was applied in electrochemistry and catalysis and exhibited enhanced performance. Display Omitted - Highlights: • CNAMs with mesoporous structure are achieved via a simple microwave-assisted hydrothermal method. • Morphology, structure and pore distribution of sample particles is specifically controlled. • The samples show enhanced properties in electrochemistry and catalysis due to hierarchical structure.

  3. Magnetic structures and interplay between rare-earth Ce and Fe magnetism in single-crystal CeFeAsO

    SciTech Connect (OSTI)

    Zhang, Qiang [Ames Laboratory; Tian, Wei [Ames Laboratory; Li, Haifeng [Ames Laboratory; Kim, Jong-Woo [Argonne Naitonal Laboratory; Yan, Jiaqiang [Ames Laboratory; McCallum, Robert William [Ames Laboratory; Lograsso, Thomas A. [Ames Laboratory; Zarestky, Jerel L. [Ames Laboratory; Budko, Sergey L. [Ames Laboratory; McQueeney, Robert J. [Ames Laboratory; Vaknin, David [Ames Laboratory

    2013-11-27T23:59:59.000Z

    Neutron and synchrotron resonant x-ray magnetic scattering (RXMS) complemented by heat capacity and resistivity measurements reveal the evolution of the magnetic structures of Fe and Ce sublattices in a CeFeAsO single crystal. The RXMS of magnetic reflections at the Ce LII edge shows a magnetic transition that is specific to the Ce antiferromagnetic long-range ordering at TCe? 4 K with short-range Ce ordering above TCe, whereas neutron diffraction measurements of a few magnetic reflections indicate a transition at T?? 12 K with an unusual order parameter. Detailed order-parameter measurements on several magnetic reflections by neutrons show a weak anomaly at 4 K that we associate with the Ce ordering. The successive transitions at TCe and T? can also be clearly identified by two anomalies in heat capacity and resistivity measurements. The higher transition temperature at T?? 12 K is mainly ascribed to Fe spin reorientation transition, below which Fe spins rotate uniformly and gradually in the ab plane. The Fe spin reorientation transition and short-range Ce ordering above TCe reflect the strong Fe-Ce couplings prior to long-range ordering of the Ce. The evolution of the intricate magnetic structures in CeFeAsO going through T? and TCe is proposed.

  4. Correlated vortex pinning in slightly orthorhombic twinned Ba(Fe1-xCox)2As2 single crystals: Possible shift of the vortex-glass/liquid transition

    SciTech Connect (OSTI)

    Bermudez, M. Marziali [Universidad de Buenos Aires; Pasquini, G. [Universidad de Buenos Aires; Budko, Sergey L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

    2013-02-28T23:59:59.000Z

    The interest in twin-boundary (TB) planes as a source of vortex pinning has been recently renewed with the discovery of the new iron-arsenide pnictide superconductors. In the family of compounds Ba(Fe1-xCox)2As2 a structural transition from a tetragonal to orthorhombic lattice takes place for compounds with xsingle crystals. Using a scaling approach we are able to determine the angular regions where correlated or uncorrelated disorder prevails. In the tetragonal samples (x>xcr) there is no twinning and we find good agreement with the expected scaling function under uncorrelated disorder, with small anisotropy values similar to those reported in the literature. We show that in the orthorhombic samples (x

  5. Optical and magneto-optical properties of single crystals of RFe{sub 2} (R = Gd, Tb, Ho, and Lu) and GdCo{sub 2} intermetallic compounds

    SciTech Connect (OSTI)

    Lee, S.J.

    1999-02-12T23:59:59.000Z

    The author has studied the diagonal and off-diagonal optical conductivity of RFe{sub 2}(R = Gd, Tb, Ho, Lu) and GdCo{sub 2} single crystals grown by the flux method. Using spectroscopic ellipsometry the author has measured the dielectric function from 1.5 to 5.5 eV. The magneto-optical Kerr spectrometer at temperatures between 7 and 295 K and applied magnetic fields between 0.5 to 1.6 T. The apparatus and calibration method are described in detail. Using magneto-optical data and optical constants he derives the experimental value of the off-diagonal conductivity components. Theoretical calculations of optical conductivities and magneto-optical parameters were performed using the tight binding-linear muffin tin orbitals method within the local spin density approximation. He applied this TB-LMTO method to LuFe{sub 2}. The theoretical results obtained agree well with the experimental data. The oxidation effects on the diagonal part of the optical conductivity were considered using a three-phase model. The oxidation effects on the magneto-optical parameters were also considered by treating the oxide layer as a nonmagnetic thin transparent layer. These corrections change not only the magnitude but also the shape of the optical conductivity and the magneto-optical parameters.

  6. Hydrogenation of the alpha,beta-Unsaturated Aldehydes Acrolein, Crotonaldehyde, and Prenal over Pt Single Crystals: A Kinetic and Sum-Frequency Generation Vibrational Spectroscopy Study

    SciTech Connect (OSTI)

    Kliewer, C.J.; Somorjai, G.A.

    2008-11-26T23:59:59.000Z

    Sum-frequency generation vibrational spectroscopy (SFG-VS) and kinetic measurements using gas chromatography have been used to study the surface reaction intermediates during the hydrogenation of three {alpha},{beta}-unsaturated aldehydes, acrolein, crotonaldehyde, and prenal, over Pt(111) at Torr pressures (1 Torr aldehyde, 100 Torr hydrogen) in the temperature range of 295K to 415K. SFG-VS data showed that acrolein has mixed adsorption species of {eta}{sub 2}-di-{sigma}(CC)-trans, {eta}{sub 2}-di-{sigma}(CC)-cis as well as highly coordinated {eta}{sub 3} or {eta}{sub 4} species. Crotonaldehyde adsorbed to Pt(111) as {eta}{sub 2} surface intermediates. SFG-VS during prenal hydrogenation also suggested the presence of the {eta}{sub 2} adsorption species, and became more highly coordinated as the temperature was raised to 415K, in agreement with its enhanced C=O hydrogenation. The effect of catalyst surface structure was clarified by carrying out the hydrogenation of crotonaldehyde over both Pt(111) and Pt(100) single crystals while acquiring the SFG-VS spectra in situ. Both the kinetics and SFG-VS showed little structure sensitivity. Pt(100) generated more decarbonylation 'cracking' product while Pt(111) had a higher selectivity for the formation of the desired unsaturated alcohol, crotylalcohol.

  7. New oxyfluoride glass with high fluorine content and laser patterning of nonlinear optical BaAlBO{sub 3}F{sub 2} single crystal line

    SciTech Connect (OSTI)

    Shionozaki, K.; Honma, T.; Komatsu, T. [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan)

    2012-11-01T23:59:59.000Z

    A new oxyfluoride glass of 50BaF{sub 2}-25Al{sub 2}O{sub 3}-25B{sub 2}O{sub 3} (mol. %) with a large fraction of fluorine, i.e., F/(F + O) = 0.4, was prepared using a conventional melt-quenching method in order to synthesize new glass-ceramics containing nonlinear optical oxyfluoride crystals. The refractive index at 632.8 nm and ultra-violet cutoff wavelength of the glass were 1.564 and {approx}200 nm, respectively. Eu{sup 3+} ions in the glass showed a high quantum yield of 88% in the photoluminescence spectrum in the visible region. BaAlBO{sub 3}F{sub 2} crystals (size: 50-100 nm) showing second harmonic generations were formed through the crystallization of the glass. Lines consisting of BaAlBO{sub 3}F{sub 2} crystals were patterned successfully on the glass surface by laser irradiations (Yb:YVO{sub 4} laser with a wavelength of 1080 nm, laser power of 1.1 W, scanning speed of 8 {mu}m/s). High resolution transmission electron microscope observations combined with a focused ion beam technique indicate that BaAlBO{sub 3}F{sub 2} crystals are highly oriented just like a single crystal. The present study proposes that the new oxyfluoride glass and glass-ceramics prepared have a high potential for optical device applications.

  8. Cascade phonon-assisted trapping of positrons by divacancies in n-FZ-Si(P) single crystals irradiated with 15 MeV protons

    SciTech Connect (OSTI)

    Arutyunov, N. Yu., E-mail: n-arutyunov@yahoo.com [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Inst. of Ion-Plasma and Laser Technologies (Inst. of Electronics), 700187 Tashkent (Uzbekistan); Emtsev, V. V.; Oganesyan, G. A. [Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation); Krause-Rehberg, R.; Kessler, C. [Martin Luther University Halle, Department of Physics, 06120 Halle (Germany); Elsayed, M. [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Minia university, Faculty of Science, Physics Department, P.O. box 61519 Minia (Egypt); Kozlovski, V. V. [St. Petersburg State Polytechnic University, 195251 St. Petersburg (Russian Federation)

    2014-02-21T23:59:59.000Z

    The trapping of positrons by the radiation defects in moderately doped oxygen-lean n-FZ-Si(P) single crystal irradiated with 15 MeV protons has been investigated in a comparative way using the positron lifetime spectroscopy and Hall effect measurements. The experiments were carried out within a wide temperature interval ranging from 25 K – 29 K to 300 K. The positron trapping rate for divacancies was reconstructed in the course of many-stage isochronal annealing. The concentration and the charged states of divacancies (V{sub 2}{sup ?} and V{sub 2}{sup ??}) were estimated. The temperature dependency of the trapping cross section of positrons by the negatively charged divacancies is in a good agreement with the data of calculations based on the assumptions of the cascade phonon-assisted mechanism of exchange of the energy between the positron and acoustic long-wave phonons. Obeying ? T{sup ?3} law, the cross-section of the trapping of positrons by divacancies changes considerably ranging from ?1.7×10{sup ?12} cm{sup 2} (66 – 100 K) to ?2×10{sup ?14} cm{sup 2} (? 250 K). The characteristic length of trapping of the positron by V{sub 2}{sup ??} divacancy was estimated to be l{sub 0}(V{sub 2}{sup ??})?(3.4±0.2)×10{sup ?8} cm.

  9. Strained single-crystal Al{sub 2}O{sub 3} grown layer by layer on Nb (110) thin films

    SciTech Connect (OSTI)

    Welander, Paul B.; Eckstein, James N. [Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2007-06-11T23:59:59.000Z

    The authors report on the growth of single-crystal Al{sub 2}O{sub 3} thin films on Nb (110) surfaces. Niobium is grown on {alpha}-Al{sub 2}O{sub 3} (1120), followed by the evaporation of Al in an O{sub 2} background. Initially, Al{sub 2}O{sub 3} grows layer by layer with hexagonal symmetry indicating either {alpha}-Al{sub 2}O{sub 3} (0001) or {gamma}-Al{sub 2}O{sub 3} (111). Diffraction measurements show that the Al{sub 2}O{sub 3} initially grows clamped to the Nb with tensile strain near 10%. This strain relaxes with further deposition and beyond about 50 A ring , the authors observe island growth. Despite the asymmetric misfit between Al{sub 2}O{sub 3} and Nb, the strain is surprisingly isotropic. Josephson junctions employing epitaxial Al{sub 2}O{sub 3} show low effective tunnel barriers and high leakage currents.

  10. Ti-Sn alloy nanodot composites embedded in single-crystal SiO{sub 2} by low energy dynamic coimplantation

    SciTech Connect (OSTI)

    Zhao, J. P.; Meng, Y.; Huang, D. X.; Rayabarapu, R. K.; Rabalais, J. W. [Department of Chemistry, University of Houston, Houston, Texas 77204 (United States); Department of Chemistry and Physics, Lamar University, P.O. Box 10022 Beaumont, Texas 77710 (United States)

    2006-10-15T23:59:59.000Z

    Organized extremely small Ti-Sn alloy nanodots have been formed in the subsurface of SiO{sub 2} by dynamic coimplantation of isotopic {sup 48}Ti{sup +} and {sup 120}Sn{sup +} at a low kinetic energy of 9 keV into (0001) Z-cut quartz at different substrate temperatures. Transmission electron microscopy images show that the Ti-Sn alloy nanodots are single crystal and have been formed uniformly at room temperature. They are distributed in a two-dimensional array with similar size of {approx}4 nm and constant interdot spacing between each dot. The regions beyond and below the two-dimensional array are depleted of detectable nanodots. At high temperature, the distribution and crystallinity were destroyed with much smaller amorphous nanodots in a slightly deeper region. The implantation was carried out by dynamic coimplantation, rather than the commonly used sequential implantation. These results indicate that dynamic low energy coimplantation is capable of forming well-ordered two-dimensional array of alloy nanodots.

  11. Electrical properties of Pb{sub 1-x}Mn{sub x}Te single crystals with an excess of tellurium

    SciTech Connect (OSTI)

    Bagieva, G. Z., E-mail: bagieva-gjulandam@rambler.ru; Abdinova, G. D.; Mustafayev, N. B.; Abdinov, D. Sh. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan)

    2013-03-15T23:59:59.000Z

    The effect of excess Te atoms (as high as 0.5 at %) and thermal treatment at 473 K for 120 h on the electrical conductivity {sigma}, the thermopower coefficient {alpha}, and the Hall coefficient R of Pb{sub 0.96}Mn{sub 0.04}Te single crystals in the temperature range {approx}77-300 K is investigated. It is shown that excess atoms of tellurium predominantly act as acceptor impurity centers at low concentrations in unannealed samples and form antisite defects at relatively high concentrations (0.05 at % or higher) being located mainly in vacancies of the lead sublattice, and decrease the hole concentration. As a result of annealing, certain lattice defects (for example, deformational) are healed, and the accommodation process for Te atoms at lead-sublattice vacancies is intensified. These processes substantially affect the values of the electrical parameters, their temperature dependences, as well as the sign of the thermopower and Hall coefficients of the samples.

  12. Sm(Co{sub 1?x}Ni{sub x}){sub 5} ordered alloy thin films formed on Cr(100) single-crystal underlayers

    SciTech Connect (OSTI)

    Yanagawa, Takato, E-mail: yanagawa@futamoto.elect.chuo-u.ac.jp; Hotta, Yusuke; Yamada, Makoto; Ohtake, Mitsuru; Futamoto, Masaaki [Faculty of Science and Engineering, Chuo University, Bunkyo-ku, Tokyo 112-8551 (Japan); Kirino, Fumiyoshi [Graduate School of Fine Arts, Tokyo University of the Arts, Taito-ku, Tokyo 110-8714 (Japan)

    2014-05-07T23:59:59.000Z

    Sm{sub 17}(Co{sub 1?x}Ni{sub x}){sub 83} (at.?%, x?=?0, 0.2, 0.8, and 1) alloy thin films are deposited on Cr(100) single-crystal underlayers at temperatures ranging between 100 and 500?°C by molecular beam epitaxy. The effects of substrate temperature and Ni/Co composition on the film growth behavior and the detailed resulting structure are investigated. Formation of epitaxial RT{sub 5} (R: rare earth metal, T: transition metal) ordered crystals is, respectively, recognized for the films with x of 0, 0.2, 0.8, and 1 deposited at temperatures higher than 400, 400, 300, and 300?°C, whereas the films deposited below the respective temperatures consist of amorphous phases. The order degree increases with increasing the substrate temperature and the Ni content. The order degrees of films with x of 0, 0.2, 0.8, and 1 deposited at 500?°C are 0.6, 0.7, 0.8, and 0.9, respectively. A replacement of Co site in SmCo{sub 5} structure with Ni atom is useful for enhancing the formation of RT{sub 5} ordered phase.

  13. Micro benchtop optics by bulk silicon micromachining

    DOE Patents [OSTI]

    Lee, Abraham P. (Walnut Creek, CA); Pocha, Michael D. (Livermore, CA); McConaghy, Charles F. (Livermore, CA); Deri, Robert J. (Pleasanton, CA)

    2000-01-01T23:59:59.000Z

    Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

  14. The structure of adsorbed sulfur and carbon on molybdenum and rhenium single crystal surfaces, and their influence on carbon monoxide and hydrocarbon chemisorption

    SciTech Connect (OSTI)

    Kelly, D.G.

    1987-08-01T23:59:59.000Z

    An ultra-high vacuum (10/sup -10/ Torr) study was performed on the chemisorption and structures of S and C adsorbates on Mo(100), Re(0001), and Re(1010) single crystal surfaces. Both S and C adsorb strongly on Mo(100), Re(0001), and Re(1010), with adsorption energies >70 kcal/mol for coverages less than saturation. S was proposed to adsorb in the highest symmetry sites on all surfaces except for theta/sub s/ > 0.75 on Mo(100), where studies suggest two different adsorption sites. C adsorbs in a ''carbidic'' or active phase on Mo(100), where it is also proposed to adsorb in the highest symmetry sites. However, C adsorbs in a ''graphitic'' or inactive phase on Re(0001) and Re(1010). CO chemisorption on the S and C overlayers was found to be blocked (except for C on Mo(100)), with S blocking adsorption more efficiently than C. Changes in adsorption energy were determined to be caused by local crowding of CO molecules by S or C, rather than a long-range electronic interaction. Unsaturated hydrocarbons decomposed completely on Mo(100), Re(0001), and Re(1010). Similar to the results for CO chemisorption, strong adsorption of unsaturated hydrocarbons (leading to decomposition) was blocked by pre-adsorbed S, allowing only physisorption to occur (adsorption energies < 11 kcal/mol). The effect of pre-adsorbed ''graphitic'' C on Re(0001) and Re(1010) on unsaturated hydrocarbon chemisorption was the same; strong adsorption (leading to decomposition) was blocked allowing only physisorption. However, Mo(100) with pre-adsorbed ''carbidic'' carbon blocks only decomposition while allowing strong reversible molecular chemisorption (12 to 23 kcal/mol). Differences in inhibition efficiency of S and C are proposed to be caused by differences in bond distances of the adsorbates to the surface. Greater distance from the metal surface causes more interaction with neighboring metal atoms. These differences also suggest explanations for catalytic hydrodesulfurization of thiophene.

  15. Polarized X-Ray Absorption Spectroscopy of Single-Crystal Mn(V) Complexes Relevant to the Oxygen-Evolving Complex of Photosystem II

    SciTech Connect (OSTI)

    Yano, J.K.; Robblee, J.; Pushkar, Y.; Marcus, M.A.; Bendix, J.; Workman, J.M.; Collins, T.J.; Solomon, E.I.; George, S.D.; Yachandra, V.K.; /LBL, Berkeley /Copenhagen U. /Stanford U., Chem. Dept. /SLAC, SSRL

    2007-10-16T23:59:59.000Z

    High-valent Mn-oxo species have been suggested to have a catalytically important role in the water splitting reaction which occurs in the Photosystem II membrane protein. In this study, five- and six-coordinate mononuclear Mn(V) compounds were investigated by polarized X-ray absorption spectroscopy in order to understand the electronic structure and spectroscopic characteristics of high-valent Mn species. Single crystals of the Mn(V)-nitrido and Mn(V)-oxo compounds were aligned along selected molecular vectors with respect to the X-ray polarization vector using X-ray diffraction. The local electronic structure of the metal site was then studied by measuring the polarization dependence of X-ray absorption near-edge spectroscopy (XANES) pre-edge spectra (1s to 3d transition) and comparing with the results of density functional theory (DFT) calculations. The Mn(V)-nitrido compound, in which the manganese is coordinated in a tetragonally distorted octahedral environment, showed a single dominant pre-edge peak along the MnN axis that can be assigned to a strong 3dz2-4pz mixing mechanism. In the square pyramidal Mn(V)-oxo system, on the other hand, an additional peak was observed at 1 eV below the main pre-edge peak. This component was interpreted as a 1s to 3dxz,yz transition with 4px,y mixing, due to the displacement of the Mn atom out of the equatorial plane. The XANES results have been correlated to DFT calculations, and the spectra have been simulated using a TD (time-dependent)-DFT approach. The relevance of these results to understanding the mechanism of the photosynthetic water oxidation is discussed.

  16. Single-crystal studies of the Chevrel-phase superconductor La{sub x}Mo{sub 6}Se{sub 8}. 2: Physical and superconducting properties

    SciTech Connect (OSTI)

    Pena, O.; Le Berre, F.; Padiou, J.; Marchand, T. [Univ. de Rennes I (France). Chimie du Solide et Inorganique Moleculaire] [Univ. de Rennes I (France). Chimie du Solide et Inorganique Moleculaire; Horyn, R.; Wojakowski, A. [Polish Academy of Sciences, Wroclaw (Poland). Inst. of Low Temperature and Structure Research] [Polish Academy of Sciences, Wroclaw (Poland). Inst. of Low Temperature and Structure Research

    1998-03-01T23:59:59.000Z

    Single crystals of La{sub x}Mo{sub 6}Se{sub 8} have been grown and some of their magnetic, transport, and superconducting properties studied. The electrical resistivity is characterized by its high value at room temperature, its low residual resistivity ratio, and a pronounced negative curvature at high temperatures. Comparison with the isostructural compounds Mo{sub 3}Se{sub 4} (Mo{sub 6}Se{sub 8}) and LaMo{sub 6}S{sub 8} shows that this behavior is due to structural as well as to extrinsic features (e.g., brittleness due to weak intercluster bondings). The position of the Fermi level near a peak of the density of states plays an important role in the normal-state physical properties, fixing the functional forms of both resistivity and magnetic susceptibility. The superconducting state is mainly characterized by a strong lanthanum concentration dependence of the critical temperature {Tc}, by quite definite granular effects, and by a very high critical field (H{sub c2}(0) {approximately} 55 T). The intragrain critical current density, as estimated by magnetic measurements, is relatively high (4 {times} 10{sup 4} A/cm{sup 2} at zero field and 1.7 K), three times larger than the one obtained for the void compound Mo{sub 3}Se{sub 4}. The fact is due to a higher density of pinning centers in the ternary compound because of microstructural features such as microcracks or crystal defects caused by the extreme brittleness of the crystals.

  17. Rabi Wave Packets and Peculiarities of Raman Scattering in Carbon Nanotubes, Produced by High Energy Ion Beam Modification of Diamond Single Crystals

    E-Print Network [OSTI]

    Dmitry Yearchuck; Alla Dovlatova

    2011-05-26T23:59:59.000Z

    QED-model for multichain coupled qubit system, proposed in \\cite{Part1}, was confirmed by Raman scattering studies of quasi-1D carbon zigzag-shaped nanotubes (CZSNTs), produced by high energy ion beam modification of natural diamond single crystals. Multichain coupled qubit system represents itself Su-Schriffer-Heeger $\\sigma$-polaron lattice, formed in CZSNTs plus quantized external electromagnetic (EM) field. New quantum optics phenomenon - Rabi waves, predicted in \\cite{Slepyan_Yerchak} has experimentally been identified for the first time. It is shown, that Raman spectra in quasi-1D CZSNTs are quite different in comparison with well known Raman spectra in 2D those ones. They characterized by semiclassical consideration by the only one vibronic mode of Su-Schriffer-Heeger $\\sigma$-polaron lattice instead of longitudinal and transverse optical phonon $G^+$ and $G^-$modes and the out-of-plane radial breathing mode, which are observed in Raman spectra of 2D single wall nanotubes. It is consequence of 2D - 1D transition in all physical properties of nanotubes. It is shown, that strong electron-photon coupling takes place in CZSNTs by interaction with EM-field and quantum nature of EM-field has to be taken into account. It has been done for the first time in stationary spectroscopy at all. All optical spectra, in particular, Raman spectra are registered by usual stationary measurement technique in nonequilibrium conditions, which are the consequence of Rabi wave packets' formation. It leads in its turn to appearance of additional lines, corresponding to revival part of inversion dependence of joint EM-field + matter system in frequency representation.

  18. Catalyzed hydrogenation of nitrogen and ethylene on metal (Fe, Pt) single crystal surfaces and effects of coadsorption: A sum frequency generation vibrational spectroscopy study

    SciTech Connect (OSTI)

    Westerberg, Staffan Per Gustav

    2004-12-15T23:59:59.000Z

    High-pressure catalytic reactions and associated processes, such as adsorption have been studied on a molecular level on single crystal surfaces. Sum Frequency Generation (SFG) vibrational spectroscopy together with Auger Electron Spectroscopy (AES), Temperature Programmed Desorption (TPD) and Gas Chromatography (GC) were used to investigate the nature of species on catalytic surfaces and to measure the catalytic reaction rates. Special attention has been directed at studying high-pressure reactions and in particular, ammonia synthesis in order to identify reaction intermediates and the influence of adsorbates on the surface during reaction conditions. The adsorption of gases N{sub 2}, H{sub 2}, O{sub 2} and NH{sub 3} that play a role in ammonia synthesis have been studied on the Fe(111) crystal surface by sum frequency generation vibrational spectroscopy using an integrated Ultra-High Vacuum (UHV)/high-pressure system. SFG spectra are presented for the dissociation intermediates, NH{sub 2} ({approx}3325 cm{sup -1}) and NH ({approx}3235 cm{sup -1}) under high pressure of ammonia (200 Torr) on the clean Fe(111) surface. Addition of 0.5 Torr of oxygen to 200 Torr of ammonia does not significantly change the bonding of dissociation intermediates to the surface. However, it leads to a phase change of nearly 180{sup o} between the resonant and non-resonant second order non-linear susceptibility of the surface, demonstrated by the reversal of the SFG spectral features. Heating the surface in the presence of 200 Torr ammonia and 0.5 Torr oxygen reduces the oxygen coverage, which can be seen from the SFG spectra as another relative phase change of 180{sup o}. The reduction of the oxide is also supported by Auger electron spectroscopy. The result suggests that the phase change of the spectral features could serve as a sensitive indicator of the chemical environment of the adsorbates.

  19. Upper critical fields and thermally-activated transport of Nd(0.7Fe0.3) FeAs single crystal

    SciTech Connect (OSTI)

    Balakirev, Fedor F [Los Alamos National Laboratory; Jaroszynski, J [NHMFL, FSU; Hunte, F [NHMFL, FSU; Balicas, L [NHMFL, FSU; Jo, Youn - Jung [NHMFL, FSU; Raicevic, I [NHMFL, FSU; Gurevich, A [NHMFL, FSU; Larbalestier, D C [NHMFL, FSU; Fang, L [CHINA; Cheng, P [CHINA; Jia, Y [CHINA; Wen, H H [CHINA

    2008-01-01T23:59:59.000Z

    We present measurements of the resistivity and the upper critical field H{sub c2} of Nd(O{sub 0.7}F{sub 0.3})FeAs single crystals in strong DC and pulsed magnetic fields up to 45 T and 60 T, respectively. We found that the field scale of H{sub c2} is comparable to {approx}100 T of high T{sub c} cuprates. H{sub c2}(T) parallel to the c-axis exhibits a pronounced upward curvature similar to what was extracted from earlier measurements on polycrystalline samples. Thus this behavior is indeed an intrinsic feature of oxypnictides, rather than manifestation of vortex lattice melting or granularity. The orientational dependence of H{sub c2} shows deviations from the one-band Ginzburg-Landau scaling. The mass anisotropy decreases as T decreases, from 9.2 at 44K to 5 at 34K. Spin dependent magnetoresistance and nonlinearities in the Hall coefficient suggest contribution to the conductivity from electron-electron interactions modified by disorder reminiscent that of diluted magnetic semiconductors. The Ohmic resistivity measured below T{sub c} but above the irreversibility field exhibits a clear Arrhenius thermally activated behavior over 4--5 decades. The activation energy has very different field dependencies for H{parallel}ab and H{perpendicular}ab. We discuss to what extent different pairing scenarios can manifest themselves in the observed behavior of H{sub c2}, using the two-band model of superconductivity. The results indicate the importance of paramagnetic effects on H{sub c2}(T), which may significantly reduce H{sub c2}(0) as compared to H{sub c2}(0) {approx}200--300 T based on extrapolations of H{sub c2}(T) near T{sub c} down to low temperatures.

  20. Guided wave propagation in 0.67Pb,,Mg1/3Nb2/3...O30.33PbTiO3 single crystal plate poled along 001c

    E-Print Network [OSTI]

    Cao, Wenwu

    Guided wave propagation in 0.67Pb,,Mg1/3Nb2/3...O3­0.33PbTiO3 single crystal plate poled along 001c relations of Lamb waves and shear horizontal SH waves propagating in the 100 and 110 directions of 0.67Pb Mg, respectively, for waves propagating along 100 and 110 directions. These limiting velocities

  1. Energy Policy 30 (2002) 477499 Photovoltaic module quality in

    E-Print Network [OSTI]

    Kammen, Daniel M.

    Energy Policy 30 (2002) 477­499 Photovoltaic module quality in the Kenyan solar home systems market purchases of clean decentralized photovoltaic technologies. Small amorphous-silicon modules dominate. This article analyzes market failure associated with photovoltaic module quality in the Kenyan SHS market

  2. Development efforts on silicon solar cells

    SciTech Connect (OSTI)

    Sinton, R.A.; Swanson, R.M. (Stanford Univ., CA (United States))

    1992-02-01T23:59:59.000Z

    This report presents a summary of the major results from the silicon high-concentration solar cell program at Stanford University from the period 1983--1990. Following a detailed design study, efforts were focused upon experimental verification of the modeled results that predicted 28% efficiencies for a new 500X concentrator solar cell design. A history of the research progress is given detailing the critical experiments that enabled the demonstration of 19.6% cells in 1983, then subsequent improvements culminating in efficiencies over 28% by 1987. In addition to laboratory efficiency improvements, the report details advances in the understanding of the fundamental device physics and modeling of silicon solar cell operation. The latter stages of the program included the development of module-ready cells in large quantity for the EPRI prototype 500X concentrator modules. Several of these 48-cell modules are currently in the field under test.

  3. Effect of a high electric field on the conductivity of MnGa{sub 2}S{sub 4}, MnIn{sub 2}S{sub 4}, and MnGaInS{sub 4} single crystals

    SciTech Connect (OSTI)

    Niftiev, N. N. [Azerbaijan State Pedagogical University (Azerbaijan); Tagiev, O. B. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

    2009-09-15T23:59:59.000Z

    The results of studying the effect of a high electric field on the conductivity of MnGa{sub 2}S{sub 4}, MnIn{sub 2}S{sub 4}, and MnGaInS{sub 4} single crystals are reported. The activation energy is determined in high and low electric fields. It is established that the decrease in the activation energy with increasing the external voltage is associated with decreasing the depth of the potential well, in which the electron is located.

  4. Author's personal copy CO/NO and CO/NO/O2 reactions over a AuPd single crystal catalyst

    E-Print Network [OSTI]

    Goodman, Wayne

    Model catalyst CO oxidation NO reduction Surface segregation Polarization modulation Infrared reflection 0) model catalyst at near atmospheric pressures. The alloy catalyst exhibits higher CO2 formation of Pd- only TWCs is near that of Pt/Rh TWCs, it is preferred since Rh is not required. Moreover, Pd

  5. Anisotropy of the solid-state epitaxy of silicon carbide in silicon

    SciTech Connect (OSTI)

    Kukushkin, S. A., E-mail: kukushkin_s@yahoo.com; Osipov, A. V. [Russian Academy of Sciences, Institute of Problems of Machine Science (Russian Federation)

    2013-12-15T23:59:59.000Z

    A new method for the solid-state synthesis of epitaxial layers is developed, in which a substrate participates in the chemical reaction and the reaction product grows not on the substrate surface, as in traditional epitaxial methods, but inside the substrate. This method offers new opportunities for elastic-energy relaxation due to a mechanism operating only in anisotropic media, specifically, the attraction of point defects formed during the chemical reaction. The attracting point centers of dilatation form relatively stable objects, dilatation dipoles, which significantly reduce the total elastic energy. It is shown that, in crystals with cubic symmetry, the most favorable arrangement of dipoles is the ?111? direction. The theory is tested by growing silicon carbide (SiC) films on Si (111) substrates by chemical reaction with carbon monoxide CO. High-quality single-crystal SiC-4H films with thicknesses of up to 100 nm are grown on Si (111). Ellipsometric analysis showed that the optical constants of the SiC-4H films are significantly anisotropic. This is caused not only by the lattice hexagonality but also by a small amount (about 2–6%) of carbon atoms remaining in the film due to dilatation dipoles. It is shown that the optical constants of the carbon impurity correspond to strongly anisotropic highly oriented pyrolytic graphite.

  6. MATERIALS AND MANUFACTURING PROCESSES FOR HIGH-EFFICIENCY FLEXIBLE PHOTOVOLTAIC MODULES

    E-Print Network [OSTI]

    .Blakers. Centre for Sustainable Energy Systems, Australian National University, Canberra, ACT 0200, Australia solar modules is presented. Flexible modules are lightweight, roll-able, and/or foldable for storage-efficiency crystalline silicon solar cells embedded between flexible coversheets, and supported by silicone encapsulant

  7. Dense optical-electrical interface module

    SciTech Connect (OSTI)

    Paul Chang

    2000-12-21T23:59:59.000Z

    The DOIM (Dense Optical-electrical Interface Modules) is a custom-designed optical data transmission module employed in the upgrade of Silicon Vertex Detector of CDF experiment at Fermilab. Each DOIM module consists of a transmitter (TX) converting electrical differential input signals to optical outputs, a middle segment of jacketed fiber ribbon cable, and a receiver (RX) which senses the light inputs and converts them back to electrical signals. The targeted operational frequency is 53 MHz, and higher rate is achievable. This article outlines the design goals, implementation methods, production test results, and radiation hardness tests of these modules.

  8. Determination of W boson helicity fractions in top quark decays in p anti-p collisions at CDF Run II and production of endcap modules for the ATLAS Silicon Tracker

    SciTech Connect (OSTI)

    Moed, Shulamit; /Geneva U.

    2007-01-01T23:59:59.000Z

    The thesis presented here includes two parts. The first part discusses the production of endcap modules for the ATLAS SemiConductor Tracker at the University of Geneva. The ATLAS experiment is one of the two multi-purpose experiments being built at the LHC at CERN. The University of Geneva invested extensive efforts to create an excellent and efficient module production site, in which 655 endcap outer modules were constructed. The complexity and extreme requirements for 10 years of LHC operation with a high resolution, high efficiency, low noise tracking system resulted in an extremely careful, time consuming production and quality assurance of every single module. At design luminosity about 1000 particles will pass through the tracking system each 25 ns. In addition to requiring fast tracking techniques, the high particle flux causes significant radiation damage. Therefore, modules have to be constructed within tight and accurate mechanical and electrical specification. A description of the ATLAS experiment and the ATLAS Semiconductor tracker is presented, followed by a detailed overview of the module production at the University of Geneva. My personal contribution to the endcap module production at the University of Geneva was taking part, together with other physicists, in selecting components to be assembled to a module, including hybrid reception tests, measuring the I-V curve of the sensors and the modules at different stages of the production, thermal cycling the modules and performing electrical readout tests as an initial quality assurance of the modules before they were shipped to CERN. An elaborated description of all of these activities is given in this thesis. At the beginning of the production period the author developed a statistics package which enabled us to monitor the rate and quality of the module production. This package was then used widely by the ATLAS SCT institutes that built endcap modules of any type, and kept being improved and updated. The production monitoring and summary using this package is shown in this thesis. The second part of the thesis reports a measurement of the fraction of longitudinal and right-handed helicity states of W bosons in top quark decays. This measurement was done using 955 pb{sup -1} of data collected with the CDF detector at the TEvatron, where protons and anti-protons are collided with a center-of-mass energy of 1.96 TeV. the helicity fraction measurements take advantage of the fact that the angular distribution of the W boson decay products depends on the helicity state of the W which they originate from. They analyze t{bar t} events in the 'lepton+jets' channel and look at the leptonic side of decay. They construct templates for the distribution of cos{theta}*, the angle between the charged lepton and the W flight direction in the rest frame of the top quark. Using Monte Carlo techniques, they construct probability distributions ('templates') for cos{theta}* in the case of left-handed, longitudinal and right-handed Ws and a template for the background model. They extract the W helicity fractions using an unbinned likelihood fitter based on the information of these templates. The Standard Model predicts the W helicity fractions to be about 70% longitudinal and 30% left-handed, while the fraction of right-handed W bosons in top decays is highly suppressed and vanishes when neglecting the mass of the b quark.

  9. Glass-silicon column

    DOE Patents [OSTI]

    Yu, Conrad M.

    2003-12-30T23:59:59.000Z

    A glass-silicon column that can operate in temperature variations between room temperature and about 450.degree. C. The glass-silicon column includes large area glass, such as a thin Corning 7740 boron-silicate glass bonded to a silicon wafer, with an electrode embedded in or mounted on glass of the column, and with a self alignment silicon post/glass hole structure. The glass/silicon components are bonded, for example be anodic bonding. In one embodiment, the column includes two outer layers of silicon each bonded to an inner layer of glass, with an electrode imbedded between the layers of glass, and with at least one self alignment hole and post arrangement. The electrode functions as a column heater, and one glass/silicon component is provided with a number of flow channels adjacent the bonded surfaces.

  10. Identification and mitigation of performance-limiting defects in epitaxially grown kerfless silicon for solar cells

    E-Print Network [OSTI]

    Powell, Douglas M. (Douglas Michael)

    2014-01-01T23:59:59.000Z

    Reducing material use is a major driver for cost reduction of crystalline silicon photovoltaic modules. The dominant wafer fabrication process employed in the industry today, ingot casting & sawing, wastes approximately ...

  11. ZnO buffer layer for metal films on silicon substrates

    DOE Patents [OSTI]

    Ihlefeld, Jon

    2014-09-16T23:59:59.000Z

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

  12. Manifestation of light and heavy electrons in the galvanomagnetic characteristics of Te-doped n-Bi{sub 0.88}Sb{sub 0.12} single crystals

    SciTech Connect (OSTI)

    Tairov, B. A., E-mail: btairov@physics.ab.az; Ibragimova, O. I., E-mail: ofeliya_i@physics.ab.az; Rahimov, A. H. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan); Brazis, R., E-mail: brazis@pfi.lt [Semiconductor Physics Institute (Lithuania)

    2011-02-15T23:59:59.000Z

    The components of resistivity ({rho}{sub ij}), Hall coefficient (R{sub ijk}), and magnetoresistance ({rho}{sub ij,kl}) of n-Bi{sub 0.88}Sb{sub 0.12} single crystals doped with tellurium to 0.01, 0.1, and 0.2 at % have been measured in the temperature range of 77-300 K. It is concluded that light and heavy electrons are involved in transport processes. The energy spacing between the bands of light and heavy electrons is found to be 40 meV, and the ratios of the effective masses and electron mobilities are estimated as m{sub 2}*/m{sub l}* = 3 and b Almost-Equal-To 0.16, respectively.

  13. Direct evidence of a zigzag spin-chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation of single-crystal Na2IrO3

    SciTech Connect (OSTI)

    Ye, Feng [ORNL; Chi, Songxue [ORNL; Cao, Huibo [ORNL; Chakoumakos, Bryan C [ORNL; Fernandez-Baca, Jaime A [ORNL; Custelcean, Radu [ORNL; Qi, Tongfei [University of Kentucky; Korneta, O. B. [University of Kentucky, Lexington; Cao, Gang [University of Kentucky

    2012-01-01T23:59:59.000Z

    We have combined single crystal neutron and x-ray diffractions to investigate the magnetic and crystal structures of the honeycomb lattice $\\rm Na_2IrO_3$. The system orders magnetically below $18.1(2)$~K with Ir$^{4+}$ ions forming zigzag spin chains within the layered honeycomb network with ordered moment of $\\rm 0.22(1)~\\mu_B$/Ir site. Such a configuration sharply contrasts the N{\\'{e}}el or stripe states proposed in the Kitaev-Heisenberg model. The structure refinement reveals that the Ir atoms form nearly ideal 2D honeycomb lattice while the $\\rm IrO_6$ octahedra experience a trigonal distortion that is critical to the ground state. The results of this study provide much-needed experimental insights into the magnetic and crystal structure crucial to the understanding of the exotic magnetic order and possible topological characteristics in the 5$d$-electron based honeycomb lattice.

  14. Effect of carrier density and valence states on superconductivity of oxygen annealed Fe{sub 1.06}Te{sub 0.6}Se{sub 0.4} single crystals

    SciTech Connect (OSTI)

    Su, T. S.; Yin, Y. W., E-mail: yyw@ustc.edu.cn, E-mail: lixg@ustc.edu.cn; Teng, M. L.; Gong, Z. Z.; Zhang, M. J.; Li, X. G., E-mail: yyw@ustc.edu.cn, E-mail: lixg@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026 (China)

    2013-11-14T23:59:59.000Z

    The variations of carrier density and valence states in oxygen annealed Fe{sub 1.06}Te{sub 0.6}Se{sub 0.4} single crystals were studied systematically. It was found that the carrier density n{sub H} increases after oxygen annealing by Hall coefficient measurements. The X-ray photoelectron spectroscopy experiments reveal that the oxygen annealing changes Fe{sup 0} and Te{sup 0} states to Fe{sup 2+/3+} and Te{sup 4+}, respectively, while the valence variation of Se is negligible. Our results indicate that the improvement of superconductivity, such as the zero resistance transition temperature T{sub c}{sup zero}, shielding and Meissner fraction value 4?? and upper critical field H{sub c2}, could be closely related to the proper manipulation of n{sub H} and the valence states by oxygen annealing in the system.

  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. Module Configuration

    DOE Patents [OSTI]

    Oweis, Salah (Ellicott City, MD); D'Ussel, Louis (Bordeaux, FR); Chagnon, Guy (Cockeysville, MD); Zuhowski, Michael (Annapolis, MD); Sack, Tim (Cockeysville, MD); Laucournet, Gaullume (Paris, FR); Jackson, Edward J. (Taneytown, MD)

    2002-06-04T23:59:59.000Z

    A stand alone battery module including: (a) a mechanical configuration; (b) a thermal management configuration; (c) an electrical connection configuration; and (d) an electronics configuration. Such a module is fully interchangeable in a battery pack assembly, mechanically, from the thermal management point of view, and electrically. With the same hardware, the module can accommodate different cell sizes and, therefore, can easily have different capacities. The module structure is designed to accommodate the electronics monitoring, protection, and printed wiring assembly boards (PWAs), as well as to allow airflow through the module. A plurality of modules may easily be connected together to form a battery pack. The parts of the module are designed to facilitate their manufacture and assembly.

  17. Testing Protocol for Module Encapsulant Creep (Presentation)

    SciTech Connect (OSTI)

    Kempe, M. D.; Miller, D. C.; Wohlgemuth, J. H.; Kurtz, S. R.; Moseley, J. M.; Shah, Q.; Tamizhmani, G.; Sakurai, K.; Inoue, M.; Doi, T.; Masuda, A.

    2012-02-01T23:59:59.000Z

    Recently there has been an interest in the use of thermoplastic encapsulant materials in photovoltaic modules to replace chemically crosslinked materials, e.g., ethylene-vinyl acetate. The related motivations include the desire to: reduce lamination time or temperature; use less moisture-permeable materials; or use materials with better corrosion characteristics. However, the use of any thermoplastic material in a high-temperature environment raises safety and performance concerns, as the standardized tests currently do not expose the modules to temperatures in excess of 85C, yet modules may experience temperatures above 100C in operation. Here we constructed eight pairs of crystalline-silicon modules and eight pairs of glass/encapsulation/glass mock modules using different encapsulation materials of which only two were designed to chemically crosslink. One module set was exposed outdoors with insulation on the back side in Arizona in the summer, and an identical set was exposed in environmental chambers. High precision creep measurements and performance measurements indicate that despite many of these polymeric materials being in the melt state at some of the highest outdoor temperatures achievable, very little creep was seen because of their high viscosity, temperature heterogeneity across the modules, and in the case of the crystalline-silicon modules, the physical restraint of the backsheet. These findings have very important implications for the development of IEC and UL qualification and safety standards, and in regards to the necessary level of cure during the processing of crosslinking encapsulants.

  18. Experimental verification of electro-refractive phase modulation in graphene

    E-Print Network [OSTI]

    Mohsin, Muhammad; Schall, Daniel; Otto, Martin; Matheisen, Christopher; Giesecke, Anna Lena; Sagade, Abhay A; Kurz, Heinrich

    2015-01-01T23:59:59.000Z

    Graphene has been considered as a promising material for opto-electronic devices, because of its tunable and wideband optical properties. In this work, we demonstrate electro-refractive phase modulation in graphene at wavelengths from 1530 to 1570 nm. By integrating a gated graphene layer in a silicon-waveguide based Mach-Zehnder interferometer, the key parameters of a phase modulator like change in effective refractive index, insertion loss and absorption change are extracted. These experimentally obtained values are well reproduced by simulations and design guidelines are provided to make graphene devices competitive to contemporary silicon based phase modulators for on-chip applications.

  19. Highly Efficient Silicon Light Emitting Diode

    E-Print Network [OSTI]

    Leminh Holleman Wallinga; P. Leminh; J. Holleman; H. Wallinga

    2000-01-01T23:59:59.000Z

    silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap

  20. Micromachined silicon electrostatic chuck

    DOE Patents [OSTI]

    Anderson, R.A.; Seager, C.H.

    1996-12-10T23:59:59.000Z

    An electrostatic chuck is faced with a patterned silicon plate, created by micromachining a silicon wafer, which is attached to a metallic base plate. Direct electrical contact between the chuck face (patterned silicon plate`s surface) and the silicon wafer it is intended to hold is prevented by a pattern of flat-topped silicon dioxide islands that protrude less than 5 micrometers from the otherwise flat surface of the chuck face. The islands may be formed in any shape. Islands may be about 10 micrometers in diameter or width and spaced about 100 micrometers apart. One or more concentric rings formed around the periphery of the area between the chuck face and wafer contain a low-pressure helium thermal-contact gas used to assist heat removal during plasma etching of a silicon wafer held by the chuck. The islands are tall enough and close enough together to prevent silicon-to-silicon electrical contact in the space between the islands, and the islands occupy only a small fraction of the total area of the chuck face, typically 0.5 to 5 percent. The pattern of the islands, together with at least one hole bored through the silicon veneer into the base plate, will provide sufficient gas-flow space to allow the distribution of the helium thermal-contact gas. 6 figs.

  1. Electric field geometries dominate quantum transport coupling in silicon nanoring

    SciTech Connect (OSTI)

    Lee, Tsung-Han, E-mail: askaleeg@gmail.com, E-mail: sfhu.hu@gmail.com; Hu, Shu-Fen, E-mail: askaleeg@gmail.com, E-mail: sfhu.hu@gmail.com [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China)

    2014-03-28T23:59:59.000Z

    Investigations on the relation between the geometries of silicon nanodevices and the quantum phenomenon they exhibit, such as the Aharonov–Bohm (AB) effect and the Coulomb blockade, were conducted. An arsenic doped silicon nanoring coupled with a nanowire by electron beam lithography was fabricated. At 1.47?K, Coulomb blockade oscillations were observed under modulation from the top gate voltage, and a periodic AB oscillation of ?B?=?0.178?T was estimated for a ring radius of 86?nm under a high sweeping magnetic field. Modulating the flat top gate and the pointed side gate was performed to cluster and separate the many electron quantum dots, which demonstrated that quantum confinement and interference effects coexisted in the doped silicon nanoring.

  2. Hypersonic and dielectric anomalies of ,,Pb,,Zn1/3Nb2/3...O3...0.905,,PbTiO3...0.095 single crystal Chi-Shun Tu, F.-C. Chao, C.-H. Yeh, and C.-L. Tsai

    E-Print Network [OSTI]

    Hypersonic and dielectric anomalies of ,,Pb,,Zn1/3Nb2/3...O3...0.905,,PbTiO3...0.095 single crystal scattering and dielectric permittivity on PZN-9.5%PT to look for both hypersonic and dielectric anomalies

  3. Method for producing silicon nitride/silicon carbide composite

    DOE Patents [OSTI]

    Dunmead, Stephen D. (Midland, MI); Weimer, Alan W. (Midland, MI); Carroll, Daniel F. (Midland, MI); Eisman, Glenn A. (Midland, MI); Cochran, Gene A. (Midland, MI); Susnitzky, David W. (Midland, MI); Beaman, Donald R. (Midland, MI); Nilsen, Kevin J. (Midland, MI)

    1996-07-23T23:59:59.000Z

    Silicon carbide/silicon nitride composites are prepared by carbothermal reduction of crystalline silica powder, carbon powder and optionally crsytalline silicon nitride powder. The crystalline silicon carbide portion of the composite has a mean number diameter less than about 700 nanometers and contains nitrogen.

  4. Structure, defects, and strain in silicon-silicon oxide interfaces

    SciTech Connect (OSTI)

    Kova?evi?, Goran, E-mail: gkova@irb.hr; Pivac, Branko [Department of Materials Physics, Rudjer Boskovic Institute, Bijeni?ka 56, P.O.B. 180, HR-10002 Zagreb (Croatia)

    2014-01-28T23:59:59.000Z

    The structure of the interfaces between silicon and silicon-oxide is responsible for proper functioning of MOSFET devices while defects in the interface can deteriorate this function and lead to their failure. In this paper we modeled this interface and characterized its defects and strain. MD simulations were used for reconstructing interfaces into a thermodynamically stable configuration. In all modeled interfaces, defects were found in the form of three-coordinated silicon atom, five coordinated silicon atom, threefold-coordinated oxygen atom, or displaced oxygen atom. Three-coordinated oxygen atom can be created if dangling bonds on silicon are close enough. The structure and stability of three-coordinated silicon atoms (P{sub b} defect) depend on the charge as well as on the electric field across the interface. The negatively charged P{sub b} defect is the most stable one, but the electric field resulting from the interface reduces that stability. Interfaces with large differences in periodic constants of silicon and silicon oxide can be stabilized by buckling of silicon layer. The mechanical stress resulted from the interface between silicon and silicon oxide is greater in the silicon oxide layer. Ab initio modeling of clusters representing silicon and silicon oxide shows about three time larger susceptibility to strain in silicon oxide than in silicon if exposed to the same deformation.

  5. AMORPHOUS SILICON-BASED MINIMODULES WITH SILICONE ELASTOMER ENCAPSULATION

    E-Print Network [OSTI]

    Deng, Xunming

    -based polymers (silicones) may not show this effect. Although silicones were used to encapsulate solar cells improved, which may make them suitable for encapsulating solar cells once again. We have recentlyAMORPHOUS SILICON-BASED MINIMODULES WITH SILICONE ELASTOMER ENCAPSULATION Aarohi Vijh 1

  6. Performance Testing using Silicon Devices - Analysis of Accuracy: Preprint

    SciTech Connect (OSTI)

    Sengupta, M.; Gotseff, P.; Myers, D.; Stoffel, T.

    2012-06-01T23:59:59.000Z

    Accurately determining PV module performance in the field requires accurate measurements of solar irradiance reaching the PV panel (i.e., Plane-of-Array - POA Irradiance) with known measurement uncertainty. Pyranometers are commonly based on thermopile or silicon photodiode detectors. Silicon detectors, including PV reference cells, are an attractive choice for reasons that include faster time response (10 us) than thermopile detectors (1 s to 5 s), lower cost and maintenance. The main drawback of silicon detectors is their limited spectral response. Therefore, to determine broadband POA solar irradiance, a pyranometer calibration factor that converts the narrowband response to broadband is required. Normally this calibration factor is a single number determined under clear-sky conditions with respect to a broadband reference radiometer. The pyranometer is then used for various scenarios including varying airmass, panel orientation and atmospheric conditions. This would not be an issue if all irradiance wavelengths that form the broadband spectrum responded uniformly to atmospheric constituents. Unfortunately, the scattering and absorption signature varies widely with wavelength and the calibration factor for the silicon photodiode pyranometer is not appropriate for other conditions. This paper reviews the issues that will arise from the use of silicon detectors for PV performance measurement in the field based on measurements from a group of pyranometers mounted on a 1-axis solar tracker. Also we will present a comparison of simultaneous spectral and broadband measurements from silicon and thermopile detectors and estimated measurement errors when using silicon devices for both array performance and resource assessment.

  7. Threshold irradiation dose for amorphization of silicon carbide

    SciTech Connect (OSTI)

    Snead, L.L.; Zinkle, S.J.

    1997-03-01T23:59:59.000Z

    The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si{sup +} at 1 x 10{sup -3} dpa/s and with fission neutrons irradiated at 1 x 10{sup -6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340{+-}10K.

  8. Fabrication of porous silicon membranes

    E-Print Network [OSTI]

    Yue, Wing Kong

    1988-01-01T23:59:59.000Z

    OF THE FILTER APPLICATION OF POROUS SILICON A. Density of Porous Silicon B. Stabilization of Porous Silicon Membranes C. Flow Test D. Porous Polycrystalline Silicon 54 58 62 65 vn TABLE OF CONTENTS (Continued) CHAPTER VI EXTENSIONS AND CONCLUSIONS... Membranes 13. Density Change of Porous Silicon at 125'C 14. Density Change oi' Porous Silicon at 250 C 15. Nitrogen Flow on a Porous Silicon Membrane Page 15 16 33 39 39 44 46 54 59 59 62 LIST OF FIGURES Figure 10. 12. 14. 17. 18. 19...

  9. Synthesis and characterization of alkali-metal titanium alkoxide compounds MTi(O-i-Pr) sub 5 (M = Li, Na, K): Single-crystal x-ray diffraction structure of (LiTi(O-i-Pr) sub 5 ) sub 2

    SciTech Connect (OSTI)

    Hampden-Smith, M.J.; Williams, D.S. (Univ. of New Mexico, Albuquerque (USA)); Rheingold, A.L. (Univ. of Delaware, Newark (USA))

    1990-10-03T23:59:59.000Z

    The series (MTi(O-iPr){sub 5}), M = Li, Na, or K, has been prepared by the reaction of MO-i-Pr with Ti(O-i-Pr){sub 4}. A single-crystal x-ray diffraction study revealed that (LiTi(O-i-Pr){sub 5}) crystallizes from toluene at {minus}30{degree}C in the monoclinic space group P2{sub 1}/n, with unit cell dimensions a = 11.440 (8) {angstrom}, b = 16.396 (13) {angstrom}, c = 11.838 (8) {angstrom}, {beta} = 92.59 (5){degree}, and Z = 4, as a dimer containing two approximately trigonal-bipyramidal titanium centers linked by lithium bridges. In benzene solution, all three compounds are dimeric, as revealed by cryoscopic molecular weight determination, and all three undergo an alkoxide ligand exchange process that is rapid on the {sup 1}H NMR time scale at room temperature. The positions of {nu}(M-O) are assigned based on the low-energy shifts observed upon deuteriation of the isopropoxide ligands. 23 refs., 3 figs., 3 tabs.

  10. Synthesis and single-crystal X-ray diffraction studies of new framework substituted type II clathrates, Cs{sub 8}Na{sub 16}Ag{sub x}Ge{sub 136-x} (x<7)

    SciTech Connect (OSTI)

    Beekman, M. [Department of Physics, University of South Florida, 4202 East Fowler Ave., PHY 114, Tampa, FL 33620 (United States); Wong-Ng, W. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Kaduk, J.A. [INEOS Technologies, Naperville, IL 60566 (United States); Shapiro, A. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Nolas, G.S. [Department of Physics, University of South Florida, 4202 East Fowler Ave., PHY 114, Tampa, FL 33620 (United States)], E-mail: gnolas@cas.usf.edu

    2007-03-15T23:59:59.000Z

    New inorganic type II clathrates with Ag atoms substituting for framework Ge atoms, Cs{sub 8}Na{sub 16}Ag{sub x}Ge{sub 136-x} (x=0, 5.9, and 6.7), have been synthesized by reaction of the pure elements at high temperature. Structural refinements have been performed using single crystal X-ray diffraction. The materials crystallize with the cubic type II clathrate crystal structure (space group Fd3-barm) with a=15.49262(9)A, 15.51605(6)A, and 15.51618(9) for x=0, 5.9, and 6.7, respectively, and Z=1. The structure is formed by a covalently bonded Ag-Ge framework, in which the Cs and Na atoms are found inside two types of polyhedral cages. Ag substitutes for Ge in the tetrahedrally bonded framework positions, and was found to preferentially occupy the most asymmetric 96g site. The proven ability to substitute atoms for the germanium framework should offer a route to the synthesis of new compositions of type II clathrates, materials that are of interest for potential thermoelectrics applications.

  11. Hydrogen in polar intermetallics: Syntheses and structures of the ternary Ca5Bi3D0.93, Yb5Bi3Hx, and Sm5Bi3H~1 by powder neutron or single crystal X-ray diffraction

    SciTech Connect (OSTI)

    Leon-Escamilla, E. Alejandro; Dervenagas, Panagiotis; Stasis, Constantine; Corbett, John D.

    2010-01-01T23:59:59.000Z

    The syntheses of the title compounds are described in detail. Structural characterizations from refinements of single crystal X-ray diffraction data for Yb{sub 5}Bi{sub 3}H{sub x} and Sm{sub 5}Bi{sub 3}H{sub 1} and of powder neutron diffraction data for Ca{sub 5}Bi{sub 3}D{sub 0.93(3)} are reported. These confirm that all three crystallize with the heavy atom structure type of {beta}-Yb{sub 5}Sb{sub 3}, and the third gives the first proof that the deuterium lies in the center of nominal calcium tetrahedra, isostructural with the Ca{sub 5}Sb{sub 3}F-type structure. These Ca and Yb phases are particularly stable with respect to dissociation to Mn{sub 5}Si{sub 3}-type product plus H{sub 2}. Some contradictions in the literature regarding Yb{sub 5}Sb{sub 3} and Yb{sub 5}Sb{sub 3}H{sub x} phases are considered in terms of adventitious hydrogen impurities that are generated during reactions in fused silica containers at elevated temperatures.

  12. Twenty years of service at NBNM - Analysis of Spectrolab module

    SciTech Connect (OSTI)

    DHERE,N.G.; PANDIT,M.B.; GHONGADI,S.R.; QUINTANA,MICHAEL A.; KING,DAVID L.; KRATOCHVIL,JAY A.

    2000-04-11T23:59:59.000Z

    This study of adhesional strength and surface analysis of encapsulant and silicon cell samples from a Natural Bridges National Monument (NBNM) Spectrolab module is an attempt to understand from its success. The module was fabricated using polyvinyl butyral (PVB) as an encapsulant. The average adhesional shear strength of the encapsulant at the cell/encapsulant interface in this module was 4.51 MPa or {approximately} 18% lower than that in currently manufactured modules. Typical encapsulant surface composition was as follows: C 75.0 at.% O 23.2 at.%, and Si 1.6 at.%, with Ag {approximately}0.2 at.% and Pb {approximately} 0.5 at.% with some tin respectively over the grid lines and solder bond. Representative silicon cell surface composition was: K 1.4 at.%, C 20.8 at.%, Sn 0.94 at.%, O 15.1 at.%, Na 2.7 at.% and Si 59.0 at.%. The presence of tin detected on the silicon cell surface may be attributed to corrosion of solder bond. The module differs from typical contemporary modules in the use of PVB, metallic mesh type interconnection, and silicon oxide AR coating.

  13. Optical properties of silicon carbide for astrophysical applications I. New laboratory infrared reflectance spectra and optical constants

    E-Print Network [OSTI]

    Pitman, K M; Corman, A B; Speck, A K

    2008-01-01T23:59:59.000Z

    Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous d...

  14. Diffusion-driven precipitate growth and ripening of oxygen precipitates in boron doped silicon by dynamical x-ray diffraction

    SciTech Connect (OSTI)

    Will, J., E-mail: will@krist.uni-erlangen.de; Gröschel, A.; Bergmann, C.; Magerl, A. [Crystallography and Structural Physics, University of Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany); Spiecker, E. [Center for Nanoanalysis and Electron Microscopy, University of Erlangen-Nürnberg, Cauerstr. 6, 91058 Erlangen (Germany)

    2014-03-28T23:59:59.000Z

    X-ray Pendellösung fringes from three silicon single crystals measured at 900?°C are analyzed with respect to density and size of oxygen precipitates within a diffusion-driven growth model and compared with TEM investigations. It appears that boron doped (p+) material shows a higher precipitate density and a higher strain than moderately (p-) boron crystals. In-situ diffraction reveals a diffusion-driven precipitate growth followed by a second growth regime in both materials. An interpretation of the second growth regime in terms of Ostwald ripening yields surface energy values (around 70?erg/cm{sup 2}) similar to published data. Further, an increased nucleation rate by a factor of ?13 is found in the p+ sample as compared to a p- sample at a nucleation temperature of 450?°C.

  15. CDF Run IIb silicon: Stave design and testing

    SciTech Connect (OSTI)

    Rong-Shyang Lu

    2003-11-07T23:59:59.000Z

    The CDF Silicon Vertex Detectors (SVX) have been shown to be excellent tools for heavy flavor physics, with the secondary vertex detection and good vertex resolution.The CDF RunIIb Silicon Vertex Detector (SVXIIb) was designed to be a radiation tolerant replacement for the current SVXII which was not anticipated to survive the projected Run II luminosity dose. The outer five layers use identical structural elements, called staves, to support six silicon sensors on each side. The stave is composed of carbon fiber skins on a foam core with a built-in cooling tube. Copper on Kapton bus cable carriers power and data/control signals underneath three silicon modules on each side of the stave. A Hybrid equipped with four new SVX4 chips are used to readout two silicon sensors on each module which can be readout and tested independently. This new design concept leads to a very compact mechanical and electrical detecting unit, allowing streamline production and ease of testing and installation. A description of the design and mechanical performance of the stave is given. They also present here results on the electrical performance obtained using prototype staves as well as results with the first pre-production parts.

  16. Crystalline Silicon Photovoltaics Research

    Broader source: Energy.gov [DOE]

    DOE supports crystalline silicon photovoltaic (PV) research and development efforts that lead to market-ready technologies. Below are a list of the projects, summary of the benefits, and discussion...

  17. Numerical and experimental study of the thermal stress of silicon induced by a millisecond laser

    SciTech Connect (OSTI)

    Wang Xi; Qin Yuan; Wang Bin; Zhang Liang; Shen Zhonghua; Lu Jian; Ni Xiaowu

    2011-07-20T23:59:59.000Z

    A spatial axisymmetric finite element model of single-crystal silicon irradiated by a 1064 nm millisecond laser is used to investigate the thermal stress damage induced by a millisecond laser. The transient temperature field and the thermal stress field for 2 ms laser irradiation with a laser fluence of 254 J/cm{sup 2} are obtained. The numerical simulation results indicate that the hoop stresses along the r axis on the front surface are compressive stress within the laser spot and convert to tensile stress outside the laser spot, while the radial stresses along the r axis on the front surface and on the z axis are compressive stress. The temperature of the irradiated center is the highest temperature obtained, yet the stress is not always highest during laser irradiation. At the end of the laser irradiation, the maximal hoop stress is located at r=0.5 mm and the maximal radial stress is located at r=0.76 mm. The temperature measurement experiments are performed by IR pyrometer. The numerical result of the temperature field is consistent with the experimental result. The damage morphologies of silicon under the action of a 254 J/cm{sup 2} laser are inspected by optical microscope. The cracks are observed initiating at r=0.5 mm and extending along the radial direction.

  18. Strong, Tough Ceramics Containing Microscopic Reinforcements: Tailoring In-Situ Reinforced Silicon Nitride Ceramics

    SciTech Connect (OSTI)

    Becher, P.F.

    1999-06-27T23:59:59.000Z

    Ceramics with their hardness, chemical stability, and refractoriness could be used to design more efficient energy generation and conversion systems as well as numerous other applications. However, we have needed to develop a fundamental understanding of how to tailor ceramics to improve their performance, especially to overcome their brittle nature. One of the advances in this respect was the incorporation of very strong microscopic rod-like reinforcements in the form of whiskers that serve to hold the ceramic together making it tougher and resistant to fracture. This microscopic reinforcement approach has a number of features that are similar to continuous fiber-reinforced ceramics; however, some of the details are modified. For instance, the strengths of the microscopic reinforcements must be higher as they typically have much stronger interfaces. For instance, single crystal silicon carbide whiskers can have tensile strengths in excess of {ge}7 GPa or >2 times that of continuous fibers. Furthermore, reinforcement pullout is limited to lengths of a few microns in the case of microscopic reinforcement due as much to the higher interfacial shear resistance as to the limit of the reinforcement lengths. On the other hand, the microscopic reinforcement approach can be generated in-situ during the processing of ceramics. A remarkable example of this is found in silicon nitride ceramics where elongated rod-like shape grains can be formed when the ceramic is fired at elevated temperatures to form a dense component.

  19. Laminated photovoltaic modules using back-contact solar cells

    DOE Patents [OSTI]

    Gee, James M. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Morgan, William P. (Albuquerque, NM); Worobey, Walter (Albuquerque, NM)

    1999-09-14T23:59:59.000Z

    Photovoltaic modules which comprise back-contact solar cells, such as back-contact crystalline silicon solar cells, positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The module designs allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

  20. Electronic conduction through single crystals of polyethylene

    E-Print Network [OSTI]

    Samson, Gerald Maurice

    1966-01-01T23:59:59.000Z

    May, 1966 Major Subjects Physics ELECTRONIC CONDUCTION THROUGH SINGLE CRYSTRLS OF POLYETHYLENE k Thesis By Gerald Maurice Samson Approved as to style and content by: naen of the Committee ad of the D artment ber ber c- The autho. u... talc o Polyot! ylone . -y, i'oo Gerald !':cur"' co Samson Directed by: Zr. Joe S. The predominant conduction mechani m through single cryo' mls op polyethylene is shown to be Schott!cy ( hernal) oui "sion . or tompora- o tu. es - bove 0 C. . "or...

  1. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStorage for Transfusion.

  2. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStorage for

  3. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStorage forPlatinum

  4. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStorage forPlatinumPlatinum

  5. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStorage

  6. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStoragePlatinum Nanoclusters

  7. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStoragePlatinum

  8. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStoragePlatinumPlatinum

  9. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenterYou are here: SNPlatinum Nanoclusters

  10. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenterYou are here: SNPlatinum

  11. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenterYou are here: SNPlatinumPlatinum

  12. Platinum Nanoclusters Out-Perform Single Crystals

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenterYou are here: SNPlatinumPlatinumPlatinum

  13. Optical properties of nanostructured silicon-rich silicon dioxide

    E-Print Network [OSTI]

    Stolfi, Michael Anthony

    2006-01-01T23:59:59.000Z

    We have conducted a study of the optical properties of sputtered silicon-rich silicon dioxide (SRO) thin films with specific application for the fabrication of erbium-doped waveguide amplifiers and lasers, polarization ...

  14. Ultratough, Thermally Stable Polycrystalline Diamond/Silicon...

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

    Ultratough, Thermally Stable Polycrystalline DiamondSilicon Carbide Nanocomposites for Drill Bits Ultratough, Thermally Stable Polycrystalline DiamondSilicon Carbide...

  15. Results of I-V Curves and Visual Inspection of PV Modules Deployed at TEP Solar Test Yard (Poster)

    SciTech Connect (OSTI)

    McNutt, P.; Wohlgemuth, J.; Miller, D.; Stoltenberg, B.

    2014-02-01T23:59:59.000Z

    The purpose of the PV Service Life Prediction project is to examine and report on how solar modules are holding up after being in the field for 5 or more years. This poster presents the common problems crystalline-silicon and thin-film modules exhibit, including details of modules from three manufactures that were tested January 13-16, 2014.

  16. Crystalline Silicon Photovolatic Cell Basics

    Broader source: Energy.gov [DOE]

    Crystalline silicon cells are made of silicon atoms connected to one another to form a crystal lattice. This lattice comprises the solid material that forms the photovoltaic (PV) cell's...

  17. Inelastic x-ray scattering study of supercooled liquid and solid silicon.

    SciTech Connect (OSTI)

    Alatas, A.; Said, A.; Sinn, H.; Alp, E.E.; Kodituwakku, C.N.; Saboungi, M.L.; Price, D.L.; X-Ray Science Division; Western Michigan Univ.; Purdue Univ.; CRMD-CNRS; CRMHT-CNRS

    2006-01-01T23:59:59.000Z

    Momentum-resolved inelastic x-ray scattering (IXS) technique is one of the powerful methods for the study of dynamical properties of a given system even in extreme conditions like high temperature and high pressure. At the same time, experimental studies of physical and structural properties of liquids have multiplied in recent years with the advent of containerless techniques. These methods reduce the possibility of contamination of specimens and remove external nucleation sites. Therefore, by combining the IXS method with the levitation method, the dynamical properties of stable liquids up to 3000 K and supercooled phase of liquids can be studied. Silicon is a basic material in the semiconductor industry and has been the subject of a large amount of experimental and theoretical studies over a long time. In the crystalline phase at ambient conditions, silicon is a diamond-structured semiconductor, but upon melting it undergoes a semiconductor-to-metal transition accompanied by significant changes in the structure and density. The coordination number increases from 4 in the solid to about 6.5 in the liquid, and liquid density is increased by about 10%. The principal purpose of the present study was to determine silicon's elastic modulus from the measurement of averaged sound speed determined from IXS. The experiments were carried out at the Advanced Photon Source (APS) beamline 3-ID with a high-resolution monochromator consisting of two nested channel-cut crystals and four backscattering analyzer setups in the horizontal scattering plane 6 m from the sample. The requirements for very high energy resolution and the basic principles of such instrumentation are discussed elsewhere as referenced. The levitation apparatus was enclosed in a bell jar specially designed for backscattering geometry with a separation of 10 cm between the sample and the detector. Silicon spheres of 2 to 3 mm in diameter were suspended in an argon gas jet and heated with a 270 W CO{sub 2} laser beam. Temperatures were measured during the experiment with a pyrometer whose operating wavelength was 0.65 {micro}m. The temperature gradient on the sample was estimated to be about +/- 20 K. The energy scans were taken for supercooled-liquid and hot-solid silicon at temperature T=1620 K. Sound velocities were determined from the initial slope of the excitation frequencies. Then, the longitudinal moduli for hotsolid and supercooled-liquid silicon were calculated from L = v{sub L}{sup 2}{rho} using measured velocities. In these calculations, density values were taken from Ohsaka et al. as referenced. Results are presented in Table 1. together with room-temperature, hot-solid single-crystal measurements, and stable-liquid values. Room-temperature longitudinal moduli were calculated from the values of the single-crystal elastic constants. They were measured between 300 K and 870 K. Since there was no phase transition up to temperature 1620 K for hot-solid silicon, it is reasonable to extrapolate these data to 1620 K in order to compare to our results for the hot solid. A significant difference (about 20%) is observed between our measurement and the extrapolated single-crystal value of the longitudinal modulus for solid silicon at temperature 1620K. This reduction of the longitudinal modulus may be an indication of the pre-melting. The factor of more than two change in the elastic modulus between supercooled liquid and hot solid at the same temperature can be attributed to the semiconductor-to-metal transition in silicon associated with melting. Also, the longitudinal modulus of the stable liquid is reported in Table 1. About a 10% difference is observed between the modulus of the supercooled and the stable liquid silicon. This can be interpreted as silicon still maintaining metallic properties with a significant increase in the degree of the directional bonding upon supercooling, as found in the x-ray diffraction and ab initio MD studies. All these results are discussed in reference.

  18. Electrochemical thinning of silicon

    DOE Patents [OSTI]

    Medernach, John W. (Albuquerque, NM)

    1994-01-01T23:59:59.000Z

    Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR).

  19. Electrochemical thinning of silicon

    DOE Patents [OSTI]

    Medernach, J.W.

    1994-01-11T23:59:59.000Z

    Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR). 14 figures.

  20. High-Speed Electro-Optic Modulator Integrated with Graphene-Boron Nitride Heterostructure and Photonic Crystal Nanocavity

    E-Print Network [OSTI]

    Gao, Yuanda; Gan, Xuetao; Li, Luozhou; Peng, Cheng; Meric, Inanc; Wang, Lei; Szep, Attila; Walker, Dennis; Hone, James; Englund, Dirk

    2014-01-01T23:59:59.000Z

    Nanoscale and power-efficient electro-optic (EO) modulators are essential components for optical interconnects that are beginning to replace electrical wiring for intra- and inter-chip communications. Silicon-based EO modulators show sufficient figures of merits regarding device footprint, speed, power consumption and modulation depth. However, the weak electro-optic effect of silicon still sets a technical bottleneck for these devices, motivating the development of modulators based on new materials. Graphene, a two-dimensional carbon allotrope, has emerged as an alternative active material for optoelectronic applications owing to its exceptional optical and electronic properties. Here, we demonstrate a high-speed graphene electro-optic modulator based on a graphene-boron nitride (BN) heterostructure integrated with a silicon photonic crystal nanocavity. Strongly enhanced light-matter interaction of graphene in a submicron cavity enables efficient electrical tuning of the cavity reflection. We observe a modul...

  1. Microstructure and properties of copper thin films on silicon substrates

    E-Print Network [OSTI]

    Jain, Vibhor Vinodkumar

    2009-05-15T23:59:59.000Z

    on Si (100) and Si (110) substrates, respectively. Single crystal Cu (111) films have a high density of growth twins, oriented parallel to the substrate surface due to low twin boundary energy and a high deposition rate. The yield strengths...

  2. Amorphous silicon photovoltaic devices

    DOE Patents [OSTI]

    Carlson, David E.; Lin, Guang H.; Ganguly, Gautam

    2004-08-31T23:59:59.000Z

    This invention is a photovoltaic device comprising an intrinsic or i-layer of amorphous silicon and where the photovoltaic device is more efficient at converting light energy to electric energy at high operating temperatures than at low operating temperatures. The photovoltaic devices of this invention are suitable for use in high temperature operating environments.

  3. In-situ Studies of the Reactions of Bifunctional and Heterocyclic Molecules over Noble Metal Single Crystal and Nanoparticle Catalysts Studied with Kinetics and Sum-Frequency Generation Vibrational Spectroscopy

    SciTech Connect (OSTI)

    Kliewer, Christopher J.

    2009-06-30T23:59:59.000Z

    Sum frequency generation surface vibrational spectroscopy (SFG-VS) in combination with gas chromatography (GC) was used in-situ to monitor surface bound reaction intermediates and reaction selectivities for the hydrogenation reactions of pyrrole, furan, pyridine, acrolein, crotonaldehyde, and prenal over Pt(111), Pt(100), Rh(111), and platinum nanoparticles under Torr reactant pressures and temperatures of 300K to 450K. The focus of this work is the correlation between the SFG-VS observed surface bound reaction intermediates and adsorption modes with the reaction selectivity, and how this is affected by catalyst structure and temperature. Pyrrole hydrogenation was investigated over Pt(111) and Rh(111) single crystals at Torr pressures. It was found that pyrrole adsorbs to Pt(111) perpendicularly by cleaving the N-H bond and binding through the nitrogen. However, over Rh(111) pyrrole adsorbs in a tilted geometry binding through the {pi}-aromatic orbitals. A surface-bound pyrroline reaction intermediate was detected over both surfaces with SFG-VS. It was found that the ring-cracking product butylamine is a reaction poison over both surfaces studied. Furan hydrogenation was studied over Pt(111), Pt(100), 10 nm cubic platinum nanoparticles and 1 nm platinum nanoparticles. The product distribution was observed to be highly structure sensitive and the acquired SFG-VS spectra reflected this sensitivity. Pt(100) exhibited more ring-cracking to form butanol than Pt(111), while the nanoparticles yielded higher selectivities for the partially saturated ring dihydrofuran. Pyridine hydrogenation was investigated over Pt(111) and Pt(100). The {alpha}-pyridyl surface adsorption mode was observed with SFG-VS over both surfaces. 1,4-dihydropyridine was seen as a surface intermediate over Pt(100) but not Pt(111). Upon heating the surfaces to 350K, the adsorbed pyridine changes to a flat-lying adsorption mode. No evidence was found for the pyridinium cation. The hydrogenation of the {alpha},{beta}-unsaturated aldehydes acrolein, crotonaldehyde, and prenal were investigated over Pt(111) and Pt(100). The selectivity for the hydrogenation of the C=C bond was found to depend on the number of methyl groups added to the bond. The adsorption modes of the three aldehydes were determined. The hydrogenation of crotonaldehyde was found to be nearly structure insensitive as the TOF and selectivity were very close to the same over Pt(111) and Pt(100). SFG-VS indicated identical surface intermediates over the two crystal faces during crotonaldehyde hydrogenation.

  4. A solar module fabrication process for HALE solar electric UAVs

    SciTech Connect (OSTI)

    Carey, P.G.; Aceves, R.C.; Colella, N.J.; Williams, K.A. [Lawrence Livermore National Lab., CA (United States); Sinton, R.A. [Private Consultant, San Jose, CA (United States); Glenn, G.S. [Spectrolab, Inc., Sylmar, CA (United States)

    1994-12-12T23:59:59.000Z

    We describe a fabrication process used to manufacture high power-to-weight-ratio flexible solar array modules for use on high-altitude-long-endurance (HALE) solar-electric unmanned air vehicles (UAVs). These modules have achieved power-to-weight ratios of 315 and 396 W/kg for 150{mu}m-thick monofacial and 110{mu}m-thick bifacial silicon solar cells, respectively. These calculations reflect average module efficiencies of 15.3% (150{mu}m) and 14.7% (110{mu}m) obtained from electrical tests performed by Spectrolab, Inc. under AMO global conditions at 25{degrees}C, and include weight contributions from all module components (solar cells, lamination material, bypass diodes, interconnect wires, and adhesive tape used to attach the modules to the wing). The fabrication, testing, and performance of 32 m{sup 2} of these modules will be described.

  5. Photovoltaic module and module arrays

    DOE Patents [OSTI]

    Botkin, Jonathan (El Cerrito, CA); Graves, Simon (Berkeley, CA); Lenox, Carl J. S. (Oakland, CA); Culligan, Matthew (Berkeley, CA); Danning, Matt (Oakland, CA)

    2012-07-17T23:59:59.000Z

    A photovoltaic (PV) module including a PV device and a frame. The PV device has a PV laminate defining a perimeter and a major plane. The frame is assembled to and encases the laminate perimeter, and includes leading, trailing, and side frame members, and an arm that forms a support face opposite the laminate. The support face is adapted for placement against a horizontal installation surface, to support and orient the laminate in a non-parallel or tilted arrangement. Upon final assembly, the laminate and the frame combine to define a unitary structure. The frame can orient the laminate at an angle in the range of 3.degree.-7.degree. from horizontal, and can be entirely formed of a polymeric material. Optionally, the arm incorporates integral feature(s) that facilitate interconnection with corresponding features of a second, identically formed PV module.

  6. Photovoltaic module and module arrays

    DOE Patents [OSTI]

    Botkin, Jonathan; Graves, Simon; Lenox, Carl J. S.; Culligan, Matthew; Danning, Matt

    2013-08-27T23:59:59.000Z

    A photovoltaic (PV) module including a PV device and a frame, The PV device has a PV laminate defining a perimeter and a major plane. The frame is assembled to and encases the laminate perimeter, and includes leading, trailing, and side frame members, and an arm that forms a support face opposite the laminate. The support face is adapted for placement against a horizontal installation surface, to support and orient the laminate in a non-parallel or tilted arrangement. Upon final assembly, the laminate and the frame combine to define a unitary structure. The frame can orient the laminate at an angle in the range of 3.degree.-7.degree. from horizontal, and can be entirely formed of a polymeric material. Optionally, the arm incorporates integral feature(s) that facilitate interconnection with corresponding features of a second, identically formed PV module.

  7. Hybrid Silicon Evanescent Lasers John E. Bowersa

    E-Print Network [OSTI]

    Bowers, John

    [2]. Finally a 110 nm thick n-doped InP spacer is used as a bonding interface to silicon. The silicon factors of the silicon waveguide and the QWs can be manipulated by the silicon waveguide dimensions silicon waveguide. For the fabricated waveguide dimensions of a 0.7 µm height (H) and 0.6 µm rib

  8. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Perez-Mendez, Victor (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1992-01-01T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  9. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  10. Making silicon stronger.

    SciTech Connect (OSTI)

    Boyce, Brad Lee

    2010-11-01T23:59:59.000Z

    Silicon microfabrication has seen many decades of development, yet the structural reliability of microelectromechanical systems (MEMS) is far from optimized. The fracture strength of Si MEMS is limited by a combination of poor toughness and nanoscale etch-induced defects. A MEMS-based microtensile technique has been used to characterize the fracture strength distributions of both standard and custom microfabrication processes. Recent improvements permit 1000's of test replicates, revealing subtle but important deviations from the commonly assumed 2-parameter Weibull statistical model. Subsequent failure analysis through a combination of microscopy and numerical simulation reveals salient aspects of nanoscale flaw control. Grain boundaries, for example, suffer from preferential attack during etch-release thereby forming failure-critical grain-boundary grooves. We will discuss ongoing efforts to quantify the various factors that affect the strength of polycrystalline silicon, and how weakest-link theory can be used to make worst-case estimates for design.

  11. Diamond-silicon carbide composite

    DOE Patents [OSTI]

    Qian, Jiang; Zhao, Yusheng

    2006-06-13T23:59:59.000Z

    Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5–8 GPa, T=1400K–2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.dot.m1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

  12. Modified silicon carbide whiskers

    DOE Patents [OSTI]

    Tiegs, T.N.; Lindemer, T.B.

    1991-05-21T23:59:59.000Z

    Silicon carbide whisker-reinforced ceramic composites are fabricated in a highly reproducible manner by beneficating the surfaces of the silicon carbide whiskers prior to their usage in the ceramic composites. The silicon carbide whiskers which contain considerable concentrations of surface oxides and other impurities which interact with the ceramic composite material to form a chemical bond are significantly reduced so that only a relatively weak chemical bond is formed between the whisker and the ceramic material. Thus, when the whiskers interact with a crack propagating into the composite the crack is diverted or deflected along the whisker-matrix interface due to the weak chemical bonding so as to deter the crack propagation through the composite. The depletion of the oxygen-containing compounds and other impurities on the whisker surfaces and near surface region is effected by heat treating the whiskers in a suitable oxygen sparging atmosphere at elevated temperatures. Additionally, a sedimentation technique may be utilized to remove whiskers which suffer structural and physical anomalies which render them undesirable for use in the composite. Also, a layer of carbon may be provided on the surface of the whiskers to further inhibit chemical bonding of the whiskers to the ceramic composite material.

  13. Modified silicon carbide whiskers

    DOE Patents [OSTI]

    Tiegs, Terry N. (Lenoir City, TN); Lindemer, Terrence B. (Oak Ridge, TN)

    1991-01-01T23:59:59.000Z

    Silicon carbide whisker-reinforced ceramic composites are fabricated in a highly reproducible manner by beneficating the surfaces of the silicon carbide whiskers prior to their usage in the ceramic composites. The silicon carbide whiskers which contain considerable concentrations of surface oxides and other impurities which interact with the ceramic composite material to form a chemical bond are significantly reduced so that only a relatively weak chemical bond is formed between the whisker and the ceramic material. Thus, when the whiskers interact with a crack propagating into the composite the crack is diverted or deflected along the whisker-matrix interface due to the weak chemical bonding so as to deter the crack propagation through the composite. The depletion of the oxygen-containing compounds and other impurities on the whisker surfaces and near surface region is effected by heat treating the whiskers in a suitable oxygen sparaging atmosphere at elevated temperatures. Additionally, a sedimentation technique may be utilized to remove whiskers which suffer structural and physical anomalies which render them undesirable for use in the composite. Also, a layer of carbon may be provided on the surface of the whiskers to further inhibit chemical bonding of the whiskers to the ceramic composite material.

  14. Fabrication and properties of microporous silicon

    E-Print Network [OSTI]

    Shao, Jianzhong

    1994-01-01T23:59:59.000Z

    Microporous silicon layers were fabricated by electrochemical etching of single crystalline silicon wafers in HF-ethanol solutions. The pore properties of porous silicon were examined by physical adsorption of nitrogen and the relationship between...

  15. Nanoscale Engineering Of Radiation Tolerant Silicon Carbide....

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

    Engineering Of Radiation Tolerant Silicon Carbide. Nanoscale Engineering Of Radiation Tolerant Silicon Carbide. Abstract: Radiation tolerance is determined by how effectively the...

  16. Silicon on insulator with active buried regions

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA)

    1998-06-02T23:59:59.000Z

    A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

  17. Silicon on insulator with active buried regions

    DOE Patents [OSTI]

    McCarthy, A.M.

    1996-01-30T23:59:59.000Z

    A method is disclosed for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors. 10 figs.

  18. Silicon on insulator with active buried regions

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA)

    1996-01-01T23:59:59.000Z

    A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

  19. Silicon on insulator with active buried regions

    DOE Patents [OSTI]

    McCarthy, A.M.

    1998-06-02T23:59:59.000Z

    A method is disclosed for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors. 10 figs.

  20. 21.9% efficient silicon bifacial solar cells

    SciTech Connect (OSTI)

    Zhou, C.Z.; Verlinden, P.J.; Crane, R.A.; Swanson, R.M. [SunPower Corp., Sunnyvale, CA (United States); Sinton, R.A. [Sinton Consulting, San Jose, CA (United States)

    1997-12-31T23:59:59.000Z

    This paper reports the efficiency of bifacial silicon solar cells and mini-modules fabricated at SunPower Corp. The best cell has AM1.5G front efficiency of 21.9% and rear efficiency of 13.9%. The mini-modules, each containing 20 bifacial cells, attain efficiency as high as the average efficiency of their individual cells. The best module has AM1.5G front efficiency of 20.66% and rear efficiency of 10.54%. Optical properties of the bifacial cells have also been measured and analyzed. The results show that bifacial cells, compared to monofacial cells, absorb less infrared light and thus they can operate at lower temperature in space.

  1. Synthesis of silicon nitride particles in pulsed Rf plasmas

    SciTech Connect (OSTI)

    Buss, R.J.; Babu, S.V.

    1995-11-01T23:59:59.000Z

    Silicon nitride (hydrogenated) particles are synthesized using a pulsed 13.56 Mhz glow discharge. The plasma is modulated with a square-wave on/off cycle of varying period to study the growth kinetics. In situ laser light scattering and ex situ particle analysis are used to study the nucleation and growth. For SiH{sub 4}/Ar and SiH{sub 4}/NH{sub 3} plasmas, an initial very rapid growth phase is followed by slower growth, approaching the rate of thin film deposition on adjacent flat surfaces. The average particle size can be controlled in the 10-100 nm range by adjusting the plasma-on time. The size dispersion of the particles is large and is consistent with a process of continuous nucleation during the plasma-on period. The large polydispersity is also reported for silicon particles from silane and differs from that reported in other laboratories. The silicon nitride particle morphology is compared to that of silicon and silicon carbide particles generated by the same technique. Whereas Si particles appear as rough clusters of smaller subunits, the SiC particles are smooth spheres, and the Si{sub 3}N{sub 4} particles are smooth but non-spherical. Post-plasma oxidation kinetics of the particles are studied with FTIR and are consistent with a hydrolysis mechanism proposed in earlier work with continuous plasmas. Heat treatment of the powder in an ammonia atmosphere results in the elimination of hydrogen, rendering the silicon nitride resistant to atmospheric oxidation.

  2. Beam Test of a Large Area nonn Silicon Strip Detector with Fast Binary Readout Electronics

    E-Print Network [OSTI]

    Beam Test of a Large Area n­on­n Silicon Strip Detector with Fast Binary Readout Electronics Y test was carried out for the non­irradiated and the irradiated detector modules. Efficiency, noise occupancy and performance in the edge regions were analyzed using the beam test data. High efficiency

  3. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide

    SciTech Connect (OSTI)

    Jiang, Weilin; Jung, Hee Joon; Kovarik, Libor; Wang, Zhaoying; Roosendaal, Timothy J.; Zhu, Zihua; Edwards, Danny J.; Hu, Shenyang Y.; Henager, Charles H.; Kurtz, Richard J.; Wang, Yongqiang

    2015-01-01T23:59:59.000Z

    As a candidate material for fusion reactor applications, silicon carbide (SiC) undergoes transmutation reactions under high-energy neutron irradiation with magnesium as the major metallic transmutant; the others include aluminum, beryllium and phosphorus in addition to helium and hydrogen gaseous species. The impact of these transmutants on SiC structural stability is currently unknown. This study uses ion implantation to introduce Mg into SiC. Multiaxial ion-channeling analysis of the as-produced damage state suggests that there are preferred Si <100> interstitial splits. The microstructure of the annealed sample was examined using high-resolution scanning transmission electron microscopy. The results show a high concentration of likely non-faulted tetrahedral voids and possible stacking fault tetrahedra near the damage peak. In addition to lattice distortion, dislocations and intrinsic and extrinsic stacking faults are also observed. Magnesium in 3C-SiC prefers to substitute for Si and it forms precipitates of cubic Mg2Si and tetragonal MgC2. The diffusion coefficient of Mg in 3C-SiC single crystal at 1573 K has been determined to be 3.8±0.4×10e-19 m2/sec.

  4. Photovoltaic Crystalline Silicon Cell Basics

    Broader source: Energy.gov [DOE]

    To separate electrical charges, crystalline silicon cells must have a built-in electric field. Light shining on crystalline silicon may free electrons within the crystal lattice, but for these electrons to do useful work—such as provide electricity to a light bulb—they must be separated and directed into an electrical circuit.

  5. Recent developments in silicon calorimetry

    SciTech Connect (OSTI)

    Brau, J.E.

    1990-11-01T23:59:59.000Z

    We present a survey of some of the recent calorimeter applications of silicon detectors. The numerous attractive features of silicon detectors are summarized, with an emphasis on those aspects important to calorimetry. Several of the uses of this technology are summarized and referenced. We consider applications for electromagnetic calorimetry, hadronic calorimetry, and proposals for the SSC.

  6. Ultraviolet selective silicon photodiode

    E-Print Network [OSTI]

    Chintapalli, Koteswara Rao

    1992-01-01T23:59:59.000Z

    (' silicon surfa&(& that n&ost of t h&) phologeneraied hole-el( & tron pairs are k&st by surface rccornbinai ion before being nolle&. trxl hy a pr). jun?i, ion. The major cause of surl'a&. e re?omhination is probably due Io lifetim(. shortening ol' Lhe... drpth corresponded to a high& r shor4wav? length rcsponsiv- ity tlirough liis ( xperimcnial diodes with junction dcpl ha ol'0. -'I to 2 0 pm. I indmayer and Allison [4I] I'abri&. ated n+-p solar cells with junction &lcpths of approximately 0. 1, 0. 15...

  7. Compensated amorphous silicon solar cell

    DOE Patents [OSTI]

    Devaud, Genevieve (629 S. Humphrey Ave., Oak Park, IL 60304)

    1983-01-01T23:59:59.000Z

    An amorphous silicon solar cell including an electrically conductive substrate, a layer of glow discharge deposited hydrogenated amorphous silicon over said substrate and having regions of differing conductivity with at least one region of intrinsic hydrogenated amorphous silicon. The layer of hydrogenated amorphous silicon has opposed first and second major surfaces where the first major surface contacts the electrically conductive substrate and an electrode for electrically contacting the second major surface. The intrinsic hydrogenated amorphous silicon region is deposited in a glow discharge with an atmosphere which includes not less than about 0.02 atom percent mono-atomic boron. An improved N.I.P. solar cell is disclosed using a BF.sub.3 doped intrinsic layer.

  8. Ballasted photovoltaic module and module arrays

    DOE Patents [OSTI]

    Botkin, Jonathan (El Cerrito, CA); Graves, Simon (Berkeley, CA); Danning, Matt (Oakland, CA)

    2011-11-29T23:59:59.000Z

    A photovoltaic (PV) module assembly including a PV module and a ballast tray. The PV module includes a PV device and a frame. A PV laminate is assembled to the frame, and the frame includes an arm. The ballast tray is adapted for containing ballast and is removably associated with the PV module in a ballasting state where the tray is vertically under the PV laminate and vertically over the arm to impede overt displacement of the PV module. The PV module assembly can be installed to a flat commercial rooftop, with the PV module and the ballast tray both resting upon the rooftop. In some embodiments, the ballasting state includes corresponding surfaces of the arm and the tray being spaced from one another under normal (low or no wind) conditions, such that the frame is not continuously subjected to a weight of the tray.

  9. Amorphous silicon/crystalline silicon heterojunctions: The future of high-efficiency silicon solar cells

    E-Print Network [OSTI]

    Firestone, Jeremy

    ;5 Record efficiencies #12;6 Diffused-junction solar cells Diffused-junction solar cell Chemical passivation to ~650 mV #12;7 Silicon heterojunction solar cells a-Si:H provides excellent passivation of c-Si surface Heterojunction solar cell Chemical passivation Chemical passivation #12;8 Voc and silicon heterojunction solar

  10. Black Silicon Solar Thin-film Microcells Integrating Top Nanocone Structures for Broadband and Omnidirectional Light-Trapping

    E-Print Network [OSTI]

    Xu, Zhida; Brueckner, Eric P; Li, Lanfang; Jiang, Jing; Nuzzo, Ralph G; Liu, Gang L

    2014-01-01T23:59:59.000Z

    Recently developed classes of monocrystalline silicon solar microcells (u-cell) can be assembled into modules with characteristics (i.e., mechanically flexible forms, compact concentrator designs, and high-voltage outputs) that would be impossible to achieve using conventional, wafer-based approaches. In this paper, we describe a highly dense, uniform and non-periodic nanocone forest structure of black silicon (bSi) created on optically-thin (30 um) u-cells for broadband and omnidirectional light-trapping with a lithography-free and high-throughput plasma texturizing process. With optimized plasma etching conditions and a silicon nitride passivation layer, black silicon u-cells, when embedded in a polymer waveguiding layer, display dramatic increases of as much as 65.7% in short circuit current, as compared to a bare silicon device. The conversion efficiency increases from 8% to 11.5% with a small drop in open circuit voltage and fill factor.

  11. Silicon nitride/silicon carbide composite densified materials prepared using composite powders

    DOE Patents [OSTI]

    Dunmead, S.D.; Weimer, A.W.; Carroll, D.F.; Eisman, G.A.; Cochran, G.A.; Susnitzky, D.W.; Beaman, D.R.; Nilsen, K.J.

    1997-07-01T23:59:59.000Z

    Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

  12. Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites

    DOE Patents [OSTI]

    Corman, Gregory Scot (Ballston Lake, NY); Luthra, Krishan Lal (Schenectady, NY)

    1999-01-01T23:59:59.000Z

    A fiber-reinforced silicon--silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon--silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

  13. Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites

    DOE Patents [OSTI]

    Corman, Gregory Scot (Ballston Lake, NY); Luthra, Krishan Lal (Schenectady, NY)

    2002-01-01T23:59:59.000Z

    A fiber-reinforced silicon-silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon-silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

  14. Crystalline silicon growth in nickel/a-silicon bilayer

    SciTech Connect (OSTI)

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

    2013-02-05T23:59:59.000Z

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

  15. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    and Photovoltaic Performance . . . . . . . . . . . . . . .Amorphous Silicon as a Photovoltaic Material 2.1.2ii Photovoltaic Model . . . . . . . . . . .

  16. Silicon nitride ceramic comprising samaria and ytterbia

    DOE Patents [OSTI]

    Yeckley, Russell L. (Oakham, MA)

    1996-01-01T23:59:59.000Z

    This invention relates to a sintered silicon nitride ceramic comprising samaria and ytterbia for enhanced toughness.

  17. Process for forming retrograde profiles in silicon

    DOE Patents [OSTI]

    Weiner, Kurt H. (San Jose, CA); Sigmon, Thomas W. (Phoenix, AZ)

    1996-01-01T23:59:59.000Z

    A process for forming retrograde and oscillatory profiles in crystalline and polycrystalline silicon. The process consisting of introducing an n- or p-type dopant into the silicon, or using prior doped silicon, then exposing the silicon to multiple pulses of a high-intensity laser or other appropriate energy source that melts the silicon for short time duration. Depending on the number of laser pulses directed at the silicon, retrograde profiles with peak/surface dopant concentrations which vary from 1-1e4 are produced. The laser treatment can be performed in air or in vacuum, with the silicon at room temperature or heated to a selected temperature.

  18. Investigations on optoelectronic transition mechanisms of silicon nanoporous pillar array by using surface photovoltage spectroscopy and photoluminescence spectroscopy

    SciTech Connect (OSTI)

    Hu, Zhen-Gang, E-mail: huzhengang@zzu.edu.cn; Tian, Yong-Tao; Li, Xin-Jian [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450001 (China)

    2014-03-28T23:59:59.000Z

    We report the electronic transition mechanisms for hydrothermally prepared silicon nanoporous pillar array (Si-NPA), investigated by surface photovoltage (SPV) spectroscopy and photoluminescence (PL) spectroscopy. By comparing the SPV spectra of single crystal silicon (sc-Si) with that of Si-NPA, the silicon nano-crystallites (nc-Si)/SiO{sub x} nanostructure in the Si-NPA could produce SPV in the wavelength range of 300–580?nm. And 580?nm (?2.14?eV) was considered as the absorption edge of the nc-Si/SiO{sub x} nanostructure. After the sample was annealed and oxidized in air at different temperatures, both the SPV in the wavelength range of 300–580?nm and the PL emission band around 690?nm from the nc-Si/SiO{sub x} nanostructure weakened and disappeared as the annealing temperature increased from 100 to 500?°C. But both the red-infrared PL band (>710?nm) and the violet-blue PL band were enhanced by increasing the annealing temperature. After 2 years of natural oxidation in air, the SPV features for sc-Si disappeared completely, and the SPV characteristics of the nc-Si/SiO{sub x} nanostructure could be clearly observed. After analysis, the Si–O structure related localized states at the nc-Si/SiO{sub x} interface dominated the electronic transitions during the red PL emission and the SPV for the nc-Si/SiO{sub x} nanostructure in Si-NPA, the red–infrared PL was due to the Si=O structure related electronic transitions, and the violet-blue PL emission could attribute to the oxygen-related defect related recombination of the photo induced carriers.

  19. Silicone plesiotherapy molds

    SciTech Connect (OSTI)

    Karolis, C.; Reay-Young, P.S.; Walsh, W.; Velautham, G.

    1983-04-01T23:59:59.000Z

    Plesiotherapy, the treatment of superficial lesions by radioactive molds has largely been replaced by teletherapy techniques involving high energy photon and electron beams. There are, however, situations for which a short distance type treatment, in one form or another, is superior to any other presently available. Traditionally, molds have taken the form of rigid devices incorporating clamps to attach them to the patient. This ensures a reproducible geometry about a localized region since the molds are applied on a daily basis. To make such devices requires considerable skill and patience. This article describes an alternative method that eliminates the use of cumbersome devices in many situations. Silicone molds made from a plaster cast model have been found suitable for the treatment of surface lesions and especially for lesions in the oral and nasal cavities. With the use of radioactive gold seeds the molds may be left in place for a few days without fear of them moving.

  20. Concentrator silicon cell research

    SciTech Connect (OSTI)

    Green, M.A.; Wenham, S.R.; Zhang, F.; Zhao, J.; Wang, A. [New South Wales Univ., Kensington (Australia). Solar Photovoltaic Lab.

    1992-04-01T23:59:59.000Z

    This project continued the developments of high-efficiency silicon concentrator solar cells with the goal of achieving a cell efficiency in the 26 to 27 percent range at a concentration level of 150 suns of greater. The target efficiency was achieved with the new PERL (passivated emitter, rear locally diffused) cell structure, but only at low concentration levels around 20 suns. The PERL structure combines oxide passivation of both top and rear surfaces of the cells with small area contact to heavily doped regions on the top and rear surfaces. Efficiency in the 22 to 23 percent range was also demonstrated for large-area concentrator cells fabricated with the buried contact solar cell processing sequence, either when combined with prismatic covers or with other innovative approaches to reduce top contact shadowing. 19 refs.

  1. Lithium Ion Battery Performance of Silicon Nanowires With Carbon...

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

    Ion Battery Performance of Silicon Nanowires With Carbon Skin . Lithium Ion Battery Performance of Silicon Nanowires With Carbon Skin . Abstract: Silicon (Si) nanomaterials have...

  2. Rheology of silicon carbide/vinyl ester nanocomposites

    E-Print Network [OSTI]

    Yong, Virginia; Hahn, H. Thomas

    2006-01-01T23:59:59.000Z

    New York, 1999. SILICON CARBIDE/VINYL ESTER NANOCOMPOSITESRheology of Silicon Carbide/Vinyl Ester NanocompositesABSTRACT: Silicon carbide (SiC) nanoparticles with no

  3. Module Technology: Current Practice and Issues (Presentation)

    SciTech Connect (OSTI)

    Wohlgemuth, J.

    2010-10-05T23:59:59.000Z

    PV modules must provide mechanical support for the cells, protect the world from the voltages inside, protect the cells, diodes and interconnects from the weather outside, couple as much light as possible into the PV cells and minimize the temperature increase of the cells. The package must continue to serve these functions for at least 25 years as that is the typical module warranty period today. Furthermore the package must do all this for as low a cost as possible since the key to large scale PV growth is a reduction in cost while retaining excellent module reliability and durability. This paper will review current module construction practices for both crystalline silicon and thin film PV with emphasis on explaining why the present designs and materials have been selected. Possible long term issues with today's designs and materials will be discussed. Several proposed solutions to these issues will be presented, highlighting the research efforts that will be necessary in order to verify that they can cost effectively solve the identified issues.

  4. Silicon-integrated thin-film structure for electro-optic applications

    DOE Patents [OSTI]

    McKee, Rodney A. (Kingston, TN); Walker, Frederick Joseph (Oak Ridge, TN)

    2000-01-01T23:59:59.000Z

    A crystalline thin-film structure suited for use in any of an number of electro-optic applications, such as a phase modulator or a component of an interferometer, includes a semiconductor substrate of silicon and a ferroelectric, optically-clear thin film of the perovskite BaTiO.sub.3 overlying the surface of the silicon substrate. The BaTiO.sub.3 thin film is characterized in that substantially all of the dipole moments associated with the ferroelectric film are arranged substantially parallel to the surface of the substrate to enhance the electro-optic qualities of the film.

  5. Module Handbook Specialisation Photovoltaics

    E-Print Network [OSTI]

    Habel, Annegret

    Module Handbook Specialisation Photovoltaics 2nd Semester for the Master Programme REMA/EUREC Course 2008/2009 University of Northumbria Specialisation Provider: Photovoltaics #12;Specialisation Photovoltaics, University of Northumbria Module 1/Photovoltaics: PHOTOVOLTAIC CELL

  6. The development of a porous silicon nitride crossflow filter; Final report, September 1988--September 1992

    SciTech Connect (OSTI)

    NONE

    1992-09-01T23:59:59.000Z

    This report summarizes the work performed in developing a permeable form of silicon nitride for application to ceramic crossflow filters for use in advanced coal-fired electric power plants. The program was sponsored by the Department of Energy Morgantown Energy Technology Center and consisted of a design analysis and material development phase and a filter manufacture and demonstration phase. The crossflow filter design and operating requirements were defined. A filter design meeting the requirements was developed and thermal and stress analyses were performed. Material development efforts focused initially on reaction-bonded silicon nitride material. This approach was not successful, and the materials effort was refocused on the development of a permeable form of sintered silicon nitride (SSN). This effort was successful. The SSN material was used for the second phase of the program, filter manufacture and evaluation. Four half-scale SAN filter modules were fabricated. Three of the modules were qualified for filter performance tests. Tests were performed on two of the three qualified modules in the High-Temperature, High-Pressure facility at the Westinghouse Science and Technology Center. The first module failed on test when it expanded into the clamping device, causing dust leakage through the filter. The second module performed well for a cumulative 150-hr test. It displayed excellent filtration capability during the test. The blowback pulse cleaning was highly effective, and the module apparently withstood the stresses induced by the periodic pulse cleaning. Testing of the module resumed, and when the flow of combustion gas through the filter was doubled, cracks developed and the test was concluded.

  7. Modulating lignin in plants

    DOE Patents [OSTI]

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29T23:59:59.000Z

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  8. Three dimensional amorphous silicon/microcrystalline silicon solar cells

    DOE Patents [OSTI]

    Kaschmitter, J.L.

    1996-07-23T23:59:59.000Z

    Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/{micro}c-Si) solar cells are disclosed which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell. 4 figs.

  9. Three dimensional amorphous silicon/microcrystalline silicon solar cells

    DOE Patents [OSTI]

    Kaschmitter, James L. (Pleasanton, CA)

    1996-01-01T23:59:59.000Z

    Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/.mu.c-Si) solar cells which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell.

  10. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    hydrogen dilution in silane on light induced degradation of hydrogenated amor- phous silicon films for solar photovoltaichydrogen content from 14-22%[76]. Hydrogenated amorphous silicon has promise as a photovoltaic

  11. Nucleation and solidification of silicon for photovoltaics

    E-Print Network [OSTI]

    Appapillai, Anjuli T. (Anjuli Tara)

    2010-01-01T23:59:59.000Z

    The majority of solar cells produced today are made with crystalline silicon wafers, which are typically manufactured by growing a large piece of silicon and then sawing it into ~200 pm wafers, a process which converts ...

  12. Thermoelectrics Partnership: Automotive Thermoelectric Modules...

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

    Solution for Automotive Thermoelectric Modules Application Thermoelectrics Partnership: Automotive Thermoelectric Modules with Scalable Thermo- and Electro-Mechanical Interfaces...

  13. 17.1%-Efficient Multi-Scale-Textured Black Silicon Solar Cells without Dielectric Antireflection Coating: Preprint

    SciTech Connect (OSTI)

    Toor, F.; Page, M. R.; Branz, H. M.; Yuan, H. C.

    2011-07-01T23:59:59.000Z

    In this work we present 17.1%-efficient p-type single crystal Si solar cells with a multi-scale-textured surface and no dielectric antireflection coating. Multi-scale texturing is achieved by a gold-nanoparticle-assisted nanoporous etch after conventional micron scale KOH-based pyramid texturing (pyramid black etching). By incorporating geometric enhancement of antireflection, this multi-scale texturing reduces the nanoporosity depth required to make silicon 'black' compared to nanoporous planar surfaces. As a result, it improves short-wavelength spectral response (blue response), previously one of the major limiting factors in 'black-Si' solar cells. With multi-scale texturing, the spectrum-weighted average reflectance from 350- to 1000-nm wavelength is below 2% with a 100-nm deep nanoporous layer. In comparison, roughly 250-nm deep nanopores are needed to achieve similar reflectance on planar surface. Here, we characterize surface morphology, reflectivity and solar cell performance of the multi-scale textured solar cells.

  14. Optical properties of silicon carbide for astrophysical applications I. New laboratory infrared reflectance spectra and optical constants

    E-Print Network [OSTI]

    K. M. Pitman; A. M. Hofmeister; A. B. Corman; A. K. Speck

    2008-03-10T23:59:59.000Z

    Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous data to constrain abundances of these dust grains.

  15. Silicon Micromachined Dimensional Calibration Artifact for Mesoscale...

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

    Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines 1 Silicon Micromachined Dimensional Calibration Artifact for Mesoscale Measurement Machines 2...

  16. Copper doped polycrystalline silicon solar cell

    DOE Patents [OSTI]

    Lovelace, Alan M. Administrator of the National Aeronautics and Space (La Canada, CA); Koliwad, Krishna M. (La Canada, CA); Daud, Taher (La Crescenta, CA)

    1981-01-01T23:59:59.000Z

    Photovoltaic cells having improved performance are fabricated from polycrystalline silicon containing copper segregated at the grain boundaries.

  17. Silicon crystal growing by oscillating crucible technique

    DOE Patents [OSTI]

    Schwuttke, G.H.; Kim, K.M.; Smetana, P.

    1983-08-03T23:59:59.000Z

    A process for growing silicon crystals from a molten melt comprising oscillating the container during crystal growth is disclosed.

  18. Laser wafering for silicon solar.

    SciTech Connect (OSTI)

    Friedmann, Thomas Aquinas; Sweatt, William C.; Jared, Bradley Howell

    2011-03-01T23:59:59.000Z

    Current technology cuts solar Si wafers by a wire saw process, resulting in 50% 'kerf' loss when machining silicon from a boule or brick into a wafer. We want to develop a kerf-free laser wafering technology that promises to eliminate such wasteful wire saw processes and achieve up to a ten-fold decrease in the g/W{sub p} (grams/peak watt) polysilicon usage from the starting polysilicon material. Compared to today's technology, this will also reduce costs ({approx}20%), embodied energy, and green-house gas GHG emissions ({approx}50%). We will use short pulse laser illumination sharply focused by a solid immersion lens to produce subsurface damage in silicon such that wafers can be mechanically cleaved from a boule or brick. For this concept to succeed, we will need to develop optics, lasers, cleaving, and high throughput processing technologies capable of producing wafers with thicknesses < 50 {micro}m with high throughput (< 10 sec./wafer). Wafer thickness scaling is the 'Moore's Law' of silicon solar. Our concept will allow solar manufacturers to skip entire generations of scaling and achieve grid parity with commercial electricity rates. Yet, this idea is largely untested and a simple demonstration is needed to provide credibility for a larger scale research and development program. The purpose of this project is to lay the groundwork to demonstrate the feasibility of laser wafering. First, to design and procure on optic train suitable for producing subsurface damage in silicon with the required damage and stress profile to promote lateral cleavage of silicon. Second, to use an existing laser to produce subsurface damage in silicon, and third, to characterize the damage using scanning electron microscopy and confocal Raman spectroscopy mapping.

  19. Prealloyed catalyst for growing silicon carbide whiskers

    DOE Patents [OSTI]

    Shalek, Peter D. (Los Alamos, NM); Katz, Joel D. (Niagara Falls, NY); Hurley, George F. (Los Alamos, NM)

    1988-01-01T23:59:59.000Z

    A prealloyed metal catalyst is used to grow silicon carbide whiskers, especially in the .beta. form. Pretreating the metal particles to increase the weight percentages of carbon or silicon or both carbon and silicon allows whisker growth to begin immediately upon reaching growth temperature.

  20. Process of preparing tritiated porous silicon

    DOE Patents [OSTI]

    Tam, S.W.

    1997-02-18T23:59:59.000Z

    A process of preparing tritiated porous silicon is described in which porous silicon is equilibrated with a gaseous vapor containing HT/T{sub 2} gas in a diluent for a time sufficient for tritium in the gas phase to replace hydrogen present in the pore surfaces of the porous silicon. 1 fig.

  1. Process of preparing tritiated porous silicon

    DOE Patents [OSTI]

    Tam, Shiu-Wing (Downers Grove, IL)

    1997-01-01T23:59:59.000Z

    A process of preparing tritiated porous silicon in which porous silicon is equilibrated with a gaseous vapor containing HT/T.sub.2 gas in a diluent for a time sufficient for tritium in the gas phase to replace hydrogen present in the pore surfaces of the porous silicon.

  2. Alignment of the Pixel and SCT Modules for the 2004 ATLAS Combined Test Beam

    SciTech Connect (OSTI)

    ATLAS Collaboration; Ahmad, A.; Andreazza, A.; Atkinson, T.; Baines, J.; Barr, A.J.; Beccherle, R.; Bell, P.J.; Bernabeu, J.; Broklova, Z.; Bruckman de Renstrom, P.A.; Cauz, D.; Chevalier, L.; Chouridou, S.; Citterio, M.; Clark, A.; Cobal, M.; Cornelissen, T.; Correard, S.; Costa, M.J.; Costanzo, D.; Cuneo, S.; Dameri, M.; Darbo, G.; de Vivie, J.B.; Di Girolamo, B.; Dobos, D.; Drasal, Z.; Drohan, J.; Einsweiler, K.; Elsing, M.; Emelyanov, D.; Escobar, C.; Facius, K.; Ferrari, P.; Fergusson, D.; Ferrere, D.; Flick,, T.; Froidevaux, D.; Gagliardi, G.; Gallas, M.; Gallop, B.J.; Gan, K.K.; Garcia, C.; Gavrilenko, I.L.; Gemme, C.; Gerlach, P.; Golling, T.; Gonzalez-Sevilla, S.; Goodrick, M.J.; Gorfine, G.; Gottfert, T.; Grosse-Knetter, J.; Hansen, P.H.; Hara, K.; Hartel, R.; Harvey, A.; Hawkings, R.J.; Heinemann, F.E.W.; Henss, T.; Hill, J.C.; Huegging, F.; Jansen, E.; Joseph, J.; Unel, M. Karagoz; Kataoka, M.; Kersten, S.; Khomich, A.; Klingenberg, R.; Kodys, P.; Koffas, T.; Konstantinidis, N.; Kostyukhin, V.; Lacasta, C.; Lari, T.; Latorre, S.; Lester, C.G.; Liebig, W.; Lipniacka, A.; Lourerio, K.F.; Mangin-Brinet, M.; Marti i Garcia, S.; Mathes, M.; Meroni, C.; Mikulec, B.; Mindur, B.; Moed, S.; Moorhead, G.; Morettini, P.; Moyse, E.W.J.; Nakamura, K.; Nechaeva, P.; Nikolaev, K.; Parodi, F.; Parzhitskiy, S.; Pater, J.; Petti, R.; Phillips, P.W.; Pinto, B.; Poppleton, A.; Reeves, K.; Reisinger, I.; Reznicek, P.; Risso, P.; Robinson, D.; Roe, S.; Rozanov, A.; Salzburger, A.; Sandaker, H.; Santi, L.; Schiavi, C.; Schieck, J.; Schultes, J.; Sfyrla, A.; Shaw, C.; Tegenfeldt, F.; Timmermans, C.J.W.P.; Toczek, B.; Troncon, C.; Tyndel, M.; Vernocchi, F.; Virzi, J.; Anh, T. Vu; Warren, M.; Weber, J.; Weber, M.; Weidberg, A.R.; Weingarten, J.; Wellsf, P.S.; Zhelezkow, A.

    2008-06-02T23:59:59.000Z

    A small set of final prototypes of the ATLAS Inner Detector silicon tracking system(Pixel Detector and SemiConductor Tracker), were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of different flavour (electrons, pions, muons and photons) with a momentum range of 2 to 180 GeV/c. Four independent methods were used to align the silicon modules. The corrections obtained were validated using the known momenta of the beam particles and were shown to yield consistent results among the different alignment approaches. From the residual distributions, it is concluded that the precision attained in the alignmentof the silicon modules is of the order of 5 mm in their most precise coordinate.

  3. Black Silicon Enhanced Thin Film Silicon Photovoltaic Devices

    SciTech Connect (OSTI)

    Martin U. Pralle; James E. Carey

    2010-07-31T23:59:59.000Z

    SiOnyx has developed an enhanced thin film silicon photovoltaic device with improved efficiency. Thin film silicon solar cells suffer from low material absorption characteristics resulting in poor cell efficiencies. SiOnyx’s approach leverages Black Silicon, an advanced material fabricated using ultrafast lasers. The laser treated films show dramatic enhancement in optical absorption with measured values in excess of 90% in the visible spectrum and well over 50% in the near infrared spectrum. Thin film Black Silicon solar cells demonstrate 25% higher current generation with almost no impact on open circuit voltage as compared with representative control samples. The initial prototypes demonstrated an improvement of nearly 2 percentage points in the suns Voc efficiency measurement. In addition we validated the capability to scale this processing technology to the throughputs (< 5 min/m2) required for volume production using state of the art commercially available high power industrial lasers. With these results we clearly demonstrate feasibility for the enhancement of thin film solar cells with this laser processing technique.

  4. Method for processing silicon solar cells

    DOE Patents [OSTI]

    Tsuo, Y.S.; Landry, M.D.; Pitts, J.R.

    1997-05-06T23:59:59.000Z

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystalline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation. 2 figs.

  5. Method for processing silicon solar cells

    DOE Patents [OSTI]

    Tsuo, Y. Simon (Golden, CO); Landry, Marc D. (Lafayette, CO); Pitts, John R. (Lakewood, CO)

    1997-01-01T23:59:59.000Z

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystallline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation.

  6. Effects of neutron radiation on power silicon diodes at low temperatures

    E-Print Network [OSTI]

    English, Kevin Joseph

    1991-01-01T23:59:59.000Z

    pulse. After [IO]. The mechanism that describes this short ? term annealing behavior is that of the electron assisted self migration of the silicon interstitials. The total energy calculation of this mechanism was performed by Bar ? Yam.... The failure mechanism of the devices is found to be the loss of conductivity modulation in the base region of the device, caused primarily by a neutron induced degradation of the carrier lifetime. ACKNOW' GEMENT I would like to thank Karin Richeson...

  7. Microelectromechanical pump utilizing porous silicon

    DOE Patents [OSTI]

    Lantz, Jeffrey W. (Albuquerque, NM); Stalford, Harold L. (Norman, OK)

    2011-07-19T23:59:59.000Z

    A microelectromechanical (MEM) pump is disclosed which includes a porous silicon region sandwiched between an inlet chamber and an outlet chamber. The porous silicon region is formed in a silicon substrate and contains a number of pores extending between the inlet and outlet chambers, with each pore having a cross-section dimension about equal to or smaller than a mean free path of a gas being pumped. A thermal gradient is provided along the length of each pore by a heat source which can be an electrical resistance heater or an integrated circuit (IC). A channel can be formed through the silicon substrate so that inlet and outlet ports can be formed on the same side of the substrate, or so that multiple MEM pumps can be connected in series to form a multi-stage MEM pump. The MEM pump has applications for use in gas-phase MEM chemical analysis systems, and can also be used for passive cooling of ICs.

  8. Dispersion toughened silicon carbon ceramics

    DOE Patents [OSTI]

    Wei, G.C.

    1984-01-01T23:59:59.000Z

    Fracture resistant silicon carbide ceramics are provided by incorporating therein a particulate dispersoid selected from the group consisting of (a) a mixture of boron, carbon and tungsten, (b) a mixture of boron, carbon and molybdenum, (c) a mixture of boron, carbon and titanium carbide, (d) a mixture of aluminum oxide and zirconium oxide, and (e) boron nitride. 4 figures.

  9. Method for fabricating silicon cells

    DOE Patents [OSTI]

    Ruby, Douglas S. (Albuquerque, NM); Basore, Paul A. (Albuquerque, NM); Schubert, W. Kent (Albuquerque, NM)

    1998-08-11T23:59:59.000Z

    A process for making high-efficiency solar cells. This is accomplished by forming a diffusion junction and a passivating oxide layer in a single high-temperature process step. The invention includes the class of solar cells made using this process, including high-efficiency solar cells made using Czochralski-grown silicon.

  10. Method for fabricating silicon cells

    DOE Patents [OSTI]

    Ruby, D.S.; Basore, P.A.; Schubert, W.K.

    1998-08-11T23:59:59.000Z

    A process is described for making high-efficiency solar cells. This is accomplished by forming a diffusion junction and a passivating oxide layer in a single high-temperature process step. The invention includes the class of solar cells made using this process, including high-efficiency solar cells made using Czochralski-grown silicon. 9 figs.

  11. Polycrystalline thin-film solar cells and modules

    SciTech Connect (OSTI)

    Ullal, H.S.; Stone, J.L.; Zweibel, K.; Surek, T.; Mitchell, R.L.

    1991-12-01T23:59:59.000Z

    This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG&E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.

  12. Polycrystalline thin-film solar cells and modules

    SciTech Connect (OSTI)

    Ullal, H.S.; Stone, J.L.; Zweibel, K.; Surek, T.; Mitchell, R.L.

    1991-12-01T23:59:59.000Z

    This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.

  13. Cavity enhanced terahertz modulation

    SciTech Connect (OSTI)

    Born, N., E-mail: norman.born@physik.uni-marburg.de [College of Optical Sciences, University of Arizona, 1630 E University Boulevard, Tucson, Arizona 85721 (United States); Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany); Scheller, M.; Moloney, J. V. [College of Optical Sciences, University of Arizona, 1630 E University Boulevard, Tucson, Arizona 85721 (United States)] [College of Optical Sciences, University of Arizona, 1630 E University Boulevard, Tucson, Arizona 85721 (United States); Koch, M. [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)] [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)

    2014-03-10T23:59:59.000Z

    We present a versatile concept for all optical terahertz (THz) amplitude modulators based on a Fabry-Pérot semiconductor cavity design. Employing the high reflectivity of two parallel meta-surfaces allows for trapping selected THz photons within the cavity and thus only a weak optical modulation of the semiconductor absorbance is required to significantly damp the field within the cavity. The optical switching yields to modulation depths of more than 90% with insertion efficiencies of 80%.

  14. Narrow band gap amorphous silicon semiconductors

    DOE Patents [OSTI]

    Madan, A.; Mahan, A.H.

    1985-01-10T23:59:59.000Z

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  15. Bracket for photovoltaic modules

    DOE Patents [OSTI]

    Ciasulli, John; Jones, Jason

    2014-06-24T23:59:59.000Z

    Brackets for photovoltaic ("PV") modules are described. In one embodiment, a saddle bracket has a mounting surface to support one or more PV modules over a tube, a gusset coupled to the mounting surface, and a mounting feature coupled to the gusset to couple to the tube. The gusset can have a first leg and a second leg extending at an angle relative to the mounting surface. Saddle brackets can be coupled to a torque tube at predetermined locations. PV modules can be coupled to the saddle brackets. The mounting feature can be coupled to the first gusset and configured to stand the one or more PV modules off the tube.

  16. Kerfless Silicon Precursor Wafer Formed by Rapid Solidification: October 2009 - March 2010

    SciTech Connect (OSTI)

    Lorenz, A.

    2011-06-01T23:59:59.000Z

    1366 Direct Wafer technology is an ultra-low-cost, kerfless method of producing crystalline silicon wafers compatible with the existing dominant silicon PV supply chain. By doubling utilization of silicon and simplifying the wafering process and equipment, Direct Wafers will support drastic reductions in wafer cost and enable module manufacturing costs < $1/W. This Pre-Incubator subcontract enabled us to accelerate the critical advances necessary to commercialize the technology by 2012. Starting from a promising concept that was initially demonstrated using a model material, we built custom equipment necessary to validate the process in silicon, then developed sufficient understanding of the underlying physics to successfully fabricate wafers meeting target specifications. These wafers, 50 mm x 50 mm x 200 ..mu..m thick, were used to make prototype solar cells via standard industrial processes as the project final deliverable. The demonstrated 10% efficiency is already impressive when compared to most thin films, but still offers considerable room for improvement when compared to typical crystalline silicon solar cells.

  17. Membrane module assembly

    DOE Patents [OSTI]

    Kaschemekat, J.

    1994-03-15T23:59:59.000Z

    A membrane module assembly is described which is adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation. 2 figures.

  18. Module Safety Issues (Presentation)

    SciTech Connect (OSTI)

    Wohlgemuth, J.

    2012-02-01T23:59:59.000Z

    Description of how to make PV modules so that they are less likely to turn into safety hazards. Making modules inherently safer with minimum additional cost is the preferred approach for PV. Safety starts with module design to ensure redundancy within the electrical circuitry to minimize open circuits and proper mounting instructions to prevent installation related ground faults. Module manufacturers must control the raw materials and processes to ensure that that every module is built like those qualified through the safety tests. This is the reason behind the QA task force effort to develop a 'Guideline for PV Module Manufacturing QA'. Periodic accelerated stress testing of production products is critical to validate the safety of the product. Combining safer PV modules with better systems designs is the ultimate goal. This should be especially true for PV arrays on buildings. Use of lower voltage dc circuits - AC modules, DC-DC converters. Use of arc detectors and interrupters to detect arcs and open the circuits to extinguish the arcs.

  19. Amorphous silicon passivated contacts for diffused junction silicon solar cells

    SciTech Connect (OSTI)

    Bullock, J., E-mail: james.bullock@anu.edu.au; Yan, D.; Wan, Y.; Cuevas, A. [Research School of Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Demaurex, B.; Hessler-Wyser, A.; De Wolf, S. [École Polytechnique Fédérale de Lausanne (EPFL), Institute of micro engineering (IMT), Photovoltaics and Thin Film Electronic Laboratory, Maladière 71, CH-200 Neuchâtel (Switzerland)

    2014-04-28T23:59:59.000Z

    Carrier recombination at the metal contacts is a major obstacle in the development of high-performance crystalline silicon homojunction solar cells. To address this issue, we insert thin intrinsic hydrogenated amorphous silicon [a-Si:H(i)] passivating films between the dopant-diffused silicon surface and aluminum contacts. We find that with increasing a-Si:H(i) interlayer thickness (from 0 to 16?nm) the recombination loss at metal-contacted phosphorus (n{sup +}) and boron (p{sup +}) diffused surfaces decreases by factors of ?25 and ?10, respectively. Conversely, the contact resistivity increases in both cases before saturating to still acceptable values of ? 50 m? cm{sup 2} for n{sup +} and ?100 m? cm{sup 2} for p{sup +} surfaces. Carrier transport towards the contacts likely occurs by a combination of carrier tunneling and aluminum spiking through the a-Si:H(i) layer, as supported by scanning transmission electron microscopy–energy dispersive x-ray maps. We explain the superior contact selectivity obtained on n{sup +} surfaces by more favorable band offsets and capture cross section ratios of recombination centers at the c-Si/a-Si:H(i) interface.

  20. Photovoltaic module and interlocked stack of photovoltaic modules

    SciTech Connect (OSTI)

    Wares, Brian S.

    2014-09-02T23:59:59.000Z

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

  1. The CDF silicon vertex trigger

    SciTech Connect (OSTI)

    B. Ashmanskas; A. Barchiesi; A. Bardi

    2003-06-23T23:59:59.000Z

    The CDF experiment's Silicon Vertex Trigger is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a 15 {mu}sec pipeline. SVT's 35 {mu}m impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common inter-board data link, and a universal ''Merger'' board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.

  2. Spectral Reflectance of Silicon Photodiodes

    E-Print Network [OSTI]

    Atte Haapalinna; Petri Kärhä; Erkki Ikonen

    Introduction Silicon photodiodes are among the most popular photodetectors that combine high performance over a wide wavelength range with unparalleled ease of use. High-quality photodiodes, in the form of a trap detector, 1,2 have many significant applications in precision radiometry. Their predictable responsivity in visible and near-infrared ~NIR! wavelengths allows the realization of high-accuracy spectral responsivity scales. 3,4 The spectral responsivity scales can be utilized in, for example, realization of luminous intensity 5,6 and spectral irradiance scales. 7,8 The spectral responsivity of a silicon photodiode is determined by the reflectance of the diode surface r~l! and the internal quantum deficiency d~l!. The values of d~l! and r~l! can be extrapolated 4 by mathematical models. To extrapolate the val

  3. Strained Silicon on Silicon by Wafer Bonding and Layer Transfer from Relaxed SiGe Buffer

    E-Print Network [OSTI]

    Isaacson, David M.

    We report the creation of strained silicon on silicon (SSOS) substrate technology. The method uses a relaxed SiGe buffer as a template for inducing tensile strain in a Si layer, which is then bonded to another Si handle ...

  4. Nonlinear absorption in silicon nanocrystals

    SciTech Connect (OSTI)

    Korovin, S B; Orlov, A N; Prokhorov, A M; Pustovoi, V I [Natural Science Center, A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Konstantaki, M; Couris, S; Koudoumas, E [Foundation for Research and Technology-Hellas (IESL-FORTH), Institute of Electronic Structure and Lasers, Crete (Greece)

    2001-09-30T23:59:59.000Z

    The nonlinear absorption of light in silicon nanocrystals suspended in glycerol is studied by the Z-scan method. The experimental data are used for calculating the nonlinear absorption coefficient {beta}{sub Si-gl} for silicon nanocrystals in glycerol (with a volume filling factor f=2x10{sup -4}), and the coefficient {beta}{sub Si} for pure silicon with a hypothetical volume filling factor f{approx}1. For the laser radiation wavelength {lambda}=497 nm and the pulse duration {tau}=0.5 ns, these coefficients are {beta}{sub Si-gl}=1.2x10{sup -8} cm W{sup -1} and {beta}{sub Si} =7.36x10{sup -5} cm W{sup -1}, while the corresponding values for {lambda}=532 nm and {tau}=10 ns are {beta}{sub Si-gl}=5.36x10{sup -5} cm W{sup -1} and {beta}{sub Si} =0.25 cm W{sup -1}. Experiments with 540-nm, 20-ps laser pulses performed for two different filling factors equal to 2x10{sup -4} and 3x10{sup -3} gave nonlinear absorption coefficients {beta}{sub Si-gl}=2x10{sup -7} and 3.6x10{sup -6} cm W{sup -1}, respectively. Optical absorption and Raman scattering spectra of silicon nanocrystals are also studied. A theoretical analysis of the experimental results shows that optical absorption can be related to the localisation of photoexcited carriers in the conduction band. The localisation is caused by the action of strong static electric fields on an electron in a nanoparticle. (nonlinear optical phenomena)

  5. Polar nanoregions and dielectric properties in high-strain lead-free 0.93(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-0.07BaTiO{sub 3} piezoelectric single crystals

    SciTech Connect (OSTI)

    Chen, Cheng-Sao, E-mail: rickchen@cc.hwh.edu.tw [Department of Mechanical Engineering, Hwa-Hsia Institute of Technology, New Taipei City 23567, Taiwan (China); Chen, Pin-Yi [Department of Mechanical Engineering, Ming-Chi University of Technology, New Taipei City 24301, Taiwan (China); Tu, Chi-Shun [Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China)

    2014-01-07T23:59:59.000Z

    A structural coexistence of rhombohedral (R) and tetragonal (T) phases has been revealed in the (001){sub c}-cut lead-free 0.93(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}–0.07BaTiO{sub 3} (BNB7T) piezoelectric crystals, which grown by the self-flux method, in the lower temperatures by high-resolution synchrotron X-ray diffraction, reciprocal space mapping, and transmission electron microscopy. The dielectric permittivity exhibits a thermal hysteresis in the region of 120–260?°C, implying a first-order-like phase transition from R+T to T. The real part (??) of dielectric permittivity begins to deviates from the Curie-Weiss equation, ???=?C/(T ? T{sub o}), from the Burns temperature T{sub B}?=?460?°C, below which the polar nanoregions (or nanoclusters) develop and attenuate dielectric responses. The polar nanoregions of 5–10?nm were revealed by high-resolution transmission electron microscope. The normal piezoelectric coefficient d{sub 33} exhibits a rapid increase at E?=?15–20?kV/cm and reaches a maximum of d{sub 33} ?450 pC/N. The high piezoelectric response and E-field induced strain in BNB7T single crystals can be attributed to structural phase transitions under an E-field application.

  6. Silicon Sheets By Redox Assisted Chemical Exfoliation

    E-Print Network [OSTI]

    Tchalala, Mohamed Rachid; Enriquez, Hanna; Kara, Abdelkader; Lachgar, Abdessadek; Yagoubi, Said; Foy, Eddy; Vega, Enrique; Bendounan, Azzedine; Silly, Mathieu G; Sirotti, Fausto; Nitshe, Serge; Chaudanson, Damien; Jamgotchian, Haik; Aufray, Bernard; Mayne, Andrew J; Dujardin, Gérald; Oughaddou, Hamid

    2013-01-01T23:59:59.000Z

    In this paper, we report the direct chemical synthesis of silicon sheets in gram-scale quantities by chemical exfoliation of pre-processed calcium di-silicide (CaSi2). We have used a combination of X-ray photoelectron spectroscopy, transmission electron microscopy and Energy-dispersive X-ray spectroscopy to characterize the obtained silicon sheets. We found that the clean and crystalline silicon sheets show a 2-dimensional hexagonal graphitic structure.

  7. Diamond-silicon carbide composite and method

    DOE Patents [OSTI]

    Zhao, Yusheng (Los Alamos, NM)

    2011-06-14T23:59:59.000Z

    Uniformly dense, diamond-silicon carbide composites having high hardness, high fracture toughness, and high thermal stability are prepared by consolidating a powder mixture of diamond and amorphous silicon. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPam.sup.1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness.

  8. Process for strengthening silicon based ceramics

    SciTech Connect (OSTI)

    Kim, Hyoun-Ee; Moorhead, A.J.

    1991-03-07T23:59:59.000Z

    A process for strengthening silicon based ceramic monolithic materials and composite materials that contain silicon based ceramic reinforcing phases that requires that the ceramic be exposed to a wet hydrogen atmosphere at about 1400{degrees}C. The process results in a dense, tightly adherent silicon containing oxide layer that heals, blunts, or otherwise negates the detrimental effect of strength limiting flaws on the surface of the ceramic body.

  9. Wafer bonded epitaxial templates for silicon heterostructures

    DOE Patents [OSTI]

    Atwater, Jr., Harry A. (So. Pasadena, CA); Zahler, James M. (Pasadena, CA); Morral, Anna Fontcubera I (Paris, FR)

    2008-03-11T23:59:59.000Z

    A heterostructure device layer is epitaxially grown on a virtual substrate, such as an InP/InGaAs/InP double heterostructure. A device substrate and a handle substrate form the virtual substrate. The device substrate is bonded to the handle substrate and is composed of a material suitable for fabrication of optoelectronic devices. The handle substrate is composed of a material suitable for providing mechanical support. The mechanical strength of the device and handle substrates is improved and the device substrate is thinned to leave a single-crystal film on the virtual substrate such as by exfoliation of a device film from the device substrate. An upper portion of the device film exfoliated from the device substrate is removed to provide a smoother and less defect prone surface for an optoelectronic device. A heterostructure is epitaxially grown on the smoothed surface in which an optoelectronic device may be fabricated.

  10. Off-axis silicon carbide substrates

    DOE Patents [OSTI]

    Edgar, James; Dudley, Michael; Kuball, Martin; Zhang, Yi; Wang, Guan; Chen, Hui; Zhang, Yu

    2014-09-02T23:59:59.000Z

    A method of epitaxial growth of a material on a crystalline substrate includes selecting a substrate having a crystal plane that includes a plurality of terraces with step risers that join adjacent terraces. Each terrace of the plurality or terraces presents a lattice constant that substantially matches a lattice constant of the material, and each step riser presents a step height and offset that is consistent with portions of the material nucleating on adjacent terraces being in substantial crystalline match at the step riser. The method also includes preparing a substrate by exposing the crystal plane; and epitaxially growing the material on the substrate such that the portions of the material nucleating on adjacent terraces merge into a single crystal lattice without defects at the step risers.

  11. Structural alloy with a protective coating containing silicon or silicon-oxide

    DOE Patents [OSTI]

    Natesan, K.

    1992-01-01T23:59:59.000Z

    This invention is comprised of an iron-based alloy containing chromium and optionally, nickel. The alloy has a surface barrier of silicon or silicon plus oxygen which converts at high temperature to a protective silicon compound. The alloy can be used in oxygen-sulfur mixed gases at temperatures up to about 1100{degrees}C.

  12. Enhancing the Lithiation Rate of Silicon Nanowires by the Inclusion...

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

    Enhancing the Lithiation Rate of Silicon Nanowires by the Inclusion of Tin. Enhancing the Lithiation Rate of Silicon Nanowires by the Inclusion of Tin. Abstract: Silicon (Si) has a...

  13. Microstructure and properties of IN SITU toughened silicon carbide

    E-Print Network [OSTI]

    De Jonghe, Lutgard C.; Ritchie, Robert O.; Zhang, Xiao Feng

    2003-01-01T23:59:59.000Z

    IN SITU TOUGHENED SILICON CARBIDE LUTGARD C. DE JONGHE 1,2 ,In Situ Toughened Silicon Carbide Lutgard C. De Jonghe 1,2 ,USA ABSTRACT A silicon carbide with a fracture toughness as

  14. Efficient light trapping structure in thin film silicon solar cells

    E-Print Network [OSTI]

    Sheng, Xing

    Thin film silicon solar cells are believed to be promising candidates for continuing cost reduction in photovoltaic panels because silicon usage could be greatly reduced. Since silicon is an indirect bandgap semiconductor, ...

  15. Sonication standard laboratory module

    DOE Patents [OSTI]

    Beugelsdijk, Tony (Los Alamos, NM); Hollen, Robert M. (Los Alamos, NM); Erkkila, Tracy H. (Los Alamos, NM); Bronisz, Lawrence E. (Los Alamos, NM); Roybal, Jeffrey E. (Santa Fe, NM); Clark, Michael Leon (Menan, ID)

    1999-01-01T23:59:59.000Z

    A standard laboratory module for automatically producing a solution of cominants from a soil sample. A sonication tip agitates a solution containing the soil sample in a beaker while a stepper motor rotates the sample. An aspirator tube, connected to a vacuum, draws the upper layer of solution from the beaker through a filter and into another beaker. This beaker can thereafter be removed for analysis of the solution. The standard laboratory module encloses an embedded controller providing process control, status feedback information and maintenance procedures for the equipment and operations within the standard laboratory module.

  16. Water heater control module

    DOE Patents [OSTI]

    Hammerstrom, Donald J

    2013-11-26T23:59:59.000Z

    An advanced electric water heater control system that interfaces with a high temperature cut-off thermostat and an upper regulating thermostat. The system includes a control module that is electrically connected to the high-temperature cut-off thermostat and the upper regulating thermostat. The control module includes a switch to open or close the high-temperature cut-off thermostat and the upper regulating thermostat. The control module further includes circuitry configured to control said switch in response to a signal selected from the group of an autonomous signal, a communicated signal, and combinations thereof.

  17. Advanced crystallization techniques of ''solar grade'' silicon

    SciTech Connect (OSTI)

    Gasparini, M.; Alessandri, M.; Calligarich, C.; Pizzini, S.; Rava, P.; Redaelli, F.; Sardi, L.

    1982-09-01T23:59:59.000Z

    Microstructural, electrical and photovoltaic characteristics of polycristalline silicon solar cells fabricated with silicon ingots containing 5, 100 and 500 ppmw iron are reported and discussed. All silicon ingots were grown by the directional solidification technique in graphite or special quartz molds and doped intentionally with iron, in order to evaluate the potentiality of the D.S. technique when employed with solar silicon feedstocks. Results indicate that structural breakdown limits the amount of the ingot which is usable for solar cells fabrication, but also that efficiencies in excess of 10% are obtained using the ''good'' region of the ingot.

  18. Innovation and Social Capital in Silicon Valley

    E-Print Network [OSTI]

    Kenney, Martin; Patton, Donald

    2003-01-01T23:59:59.000Z

    Innovation and Social Capital in Silicon Valley * BRIEpath from social capital to innovation has been identified.social capital has for economic development and innovation.

  19. Silicon Materials and Devices (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-06-01T23:59:59.000Z

    This National Center for Photovoltaics sheet describes the capabilities of its silicon materials and devices research. The scope and core competencies and capabilities are discussed.

  20. Silicon Materials and Devices (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-06-01T23:59:59.000Z

    Capabilities fact sheet for the National Center for Photovoltaics: Silicon Materials and Devices that includes scope, core competencies and capabilities, and contact/web information.

  1. Silicon nitride having a high tensile strength

    DOE Patents [OSTI]

    Pujari, Vimal K. (Northboro, MA); Tracey, Dennis M. (Medfield, MA); Foley, Michael R. (Oxford, MA); Paille, Norman I. (Oxford, MA); Pelletier, Paul J. (Sutton, MA); Sales, Lenny C. (Grafton, MA); Willkens, Craig A. (Worcester, MA); Yeckley, Russell L. (Latrobe, PA)

    1998-01-01T23:59:59.000Z

    A ceramic body comprising at least about 80 w/o silicon nitride and having a mean tensile strength of at least about 800 MPa.

  2. Ultralow-Power Silicon Microphotonic Communications Platform

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

    second). These peta-scale machines are critical for advanced scientific modelling of climate change, biological simulations, advanced materials, and our Ultralow-Power Silicon...

  3. Engineering Metal Impurities in Multicrystalline Silicon Solar...

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

    from inexpensive low-grade silicon. Artist's impression of an intense beam of synchrotron light striking a solar cell and the resulting fluorescence image of the distribution of...

  4. Enabling Thin Silicon Solar Cell Technology

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

    cracking problem in silicon cell technology," says Budiman. "The ALS provides us with a light that allows us to measure and characterize molecular stress in a very quantitative...

  5. Module Title: Project Module Code: OPTO6005

    E-Print Network [OSTI]

    Anderson, Jim

    Ibsen, Dr Ping Hua, Prof James Wilkinson Contact (email ID) sm@orc.soton.ac.uk, mi@orc.soton.ac.uk, ph2@orc.soton.ac.uk, jsw@orc.soton.ac.uk Is the module subject to external accreditation? No If yes and optical labs of the ORC 3. Train in technical and hands-on research skills to gain technical insight

  6. The silicon microstrip sensors of the ATLAS semiconductor tracker

    SciTech Connect (OSTI)

    ATLAS SCT Collaboration; Spieler, Helmuth G.

    2007-04-13T23:59:59.000Z

    This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the Semiconductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd. supplied 92.2percent of the 15,392 installed sensors, with the remainder supplied by CiS.

  7. Procedures in Modules (1) Including all procedures within modules

    E-Print Network [OSTI]

    Procedures in Modules (1) Including all procedures within modules works very well in almost all designing these if possible #12;Procedures in Modules (2) These are very much like internal procedures Works very well in almost all programs Everything accessible in the module can also be used in the procedure

  8. GREET Pretreatment Module

    SciTech Connect (OSTI)

    Adom, Felix K.; Dunn, Jennifer B.; Han, Jeongwoo

    2014-09-01T23:59:59.000Z

    A wide range of biofuels and biochemicals can be produced from biomass via different pretreatment technologies that yield sugars. This report documents the material and energy flows that occur when fermentable sugars from four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar) are produced via dilute acid pretreatment and ammonia fiber expansion. These flows are documented for inclusion in the pretreatment module of the Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. Process simulations of each pretreatment technology were developed in Aspen Plus. Material and energy consumption data from Aspen Plus were then compiled in the GREET pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

  9. Digital optical conversion module

    DOE Patents [OSTI]

    Kotter, Dale K. (North Shelley, ID); Rankin, Richard A. (Ammon, ID)

    1991-02-26T23:59:59.000Z

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer.

  10. Digital optical conversion module

    DOE Patents [OSTI]

    Kotter, D.K.; Rankin, R.A.

    1988-07-19T23:59:59.000Z

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer. 2 figs.

  11. Absorbance modulation optical lithography

    E-Print Network [OSTI]

    Tsai, Hsin-Yu Sidney

    2007-01-01T23:59:59.000Z

    In this thesis, the concept of absorbance-modulation optical lithography (AMOL) is described, and the feasibility experimentally verified. AMOL is an implementation of nodal lithography, which is not bounded by the diffraction ...

  12. Characterization of nitrided silicon-silicon dioxide interfaces

    SciTech Connect (OSTI)

    Polignano, M.L.; Alessandri, M.; Brazzelli, D. [and others

    2000-07-01T23:59:59.000Z

    A newly-developed technique for the simultaneous characterization of the oxide-silicon interface properties and of bulk impurities was used for a systematic study of the nitridation process of thin oxides. This technique is based upon surface recombination velocity measurements, and does not require the formation of a capacitor structure, so it is very suitable for the characterization of as-grown interfaces. Oxides grown both in dry and in wet environments were considered, and nitridation processes in N{sub 2}O and in NO were compared to N{sub 2} annealing processes. The effect of nitridation temperature and duration were also studied, and RTO/RTN processes were compared to conventional furnace nitridation processes. Surface recombination velocity was correlated with nitrogen concentration at the oxide-silicon interface obtained by Secondary Ion Mass Spectroscopy (SIMS) measurements. Surface recombination velocity (hence surface state density) decreases with increasing nitrogen pile-up at the oxide-silicon interface, indicating that in nitrided interfaces surface state density is limited by nitridation. NO treatments are much more effective than N{sub 2}O treatments in the formation of nitrogen-rich interface layer and, as a consequence, in surface state reduction. Surface state density was measured in fully processed wafers before and after constant current stress. After a complete device process surface states are annealed out by hydrogen passivation, however they are reactivated by the electrical stress, and surface state results after stress were compared with data of surface recombination velocity in as-processed wafers.

  13. Designing Silicon Nanostructures for High Energy Lithium Ion...

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

    Designing Silicon Nanostructures for High Energy Lithium Ion Battery Anodes Designing Silicon Nanostructures for High Energy Lithium Ion Battery Anodes 2012 DOE Hydrogen and Fuel...

  14. Synthesis and Characterization of Silicon Clathrates for Anode...

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

    Silicon Clathrates for Anode Applications in Lithium-Ion Batteries Synthesis and Characterization of Silicon Clathrates for Anode Applications in Lithium-Ion Batteries 2012 DOE...

  15. Mesoporous Silicon Sponge as an Anti-Pulverization Structure...

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

    Mesoporous Silicon Sponge as an Anti-Pulverization Structure for High-Performance Lithium-ion Battery Anodes. Mesoporous Silicon Sponge as an Anti-Pulverization Structure for...

  16. Atomistic modeling of amorphous silicon carbide using a bond...

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

    modeling of amorphous silicon carbide using a bond-order potential. Atomistic modeling of amorphous silicon carbide using a bond-order potential. Abstract: Molecular dynamics...

  17. Irradiation-induced defect clustering and amorphization in silicon...

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

    Irradiation-induced defect clustering and amorphization in silicon carbide. Irradiation-induced defect clustering and amorphization in silicon carbide. Abstract: Previous computer...

  18. Silicon Valley Power and Oklahoma Municipal Power Authority Win...

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

    Silicon Valley Power and Oklahoma Municipal Power Authority Win 2014 Public Power Wind Awards Silicon Valley Power and Oklahoma Municipal Power Authority Win 2014 Public Power Wind...

  19. Vehicle Technologies Office Merit Review 2014: Silicon Nanowire...

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

    Technologies Office Merit Review 2014: Silicon Nanowire Anodes for Next Generation Energy Storage Vehicle Technologies Office Merit Review 2014: Silicon Nanowire Anodes for...

  20. Silicon Nanostructure-based Technology for Next Generation Energy...

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

    Silicon Nanostructure-based Technology for Next Generation Energy Storage Silicon Nanostructure-based Technology for Next Generation Energy Storage 2013 DOE Hydrogen and Fuel Cells...

  1. Vehicle Technologies Office Merit Review 2012: Silicon Nanostructure...

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

    Office Merit Review 2012: Silicon Nanostructure-based Technology for Next Generation Energy Storage Vehicle Technologies Office Merit Review 2012: Silicon Nanostructure-based...

  2. amorphous silicon carbon: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 11 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  3. amorphous silicon film: Topics by E-print Network

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

    values previously Hellman, Frances 8 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  4. amorphous hydrogenated silicon: Topics by E-print Network

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

    Gunther; Baets, Roel 2011-01-01 36 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  5. amorphous silicon epid: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 7 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  6. amorphous silicon arrays: Topics by E-print Network

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

    amorphous carbon Wang, Zhong L. 8 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  7. amorphous silicon alloy: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 11 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  8. amorphous silicon studied: Topics by E-print Network

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

    Yang, Cheng-Chieh 2012-01-01 22 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  9. amorphous silicon films: Topics by E-print Network

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

    values previously Hellman, Frances 8 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  10. amorphous silicon sensor: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 9 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  11. amorphous silicon nanoparticles: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 9 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  12. amorphous silicon alloys: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 11 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  13. amorphous silicon solar: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 26 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  14. amorphous silicon thin: Topics by E-print Network

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

    values previously Hellman, Frances 6 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  15. amorphous silicon tft: Topics by E-print Network

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    Ph. Emplit; S. Massar 2011-02-04 20 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  16. amorphous silicon photovoltaic: Topics by E-print Network

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

    properties Mazur, Eric 20 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  17. amorphous silicon final: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 7 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  18. amorphous silicon diodes: Topics by E-print Network

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

    Ph. Emplit; S. Massar 2011-02-04 9 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  19. amorphous silicon surfaces: Topics by E-print Network

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    Ph. Emplit; S. Massar 2011-02-04 10 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  20. amorphous silicon technology: Topics by E-print Network

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    technologies is presented. Then 11 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...