Sample records for amorphous silicon a-si

  1. 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...

  2. Amorphous silicon ionizing particle detectors

    DOE Patents [OSTI]

    Street, R.A.; Mendez, V.P.; Kaplan, S.N.

    1988-11-15T23:59:59.000Z

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation. 15 figs.

  3. Amorphous silicon ionizing particle detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Mendez, Victor P. (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1988-01-01T23:59:59.000Z

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.

  4. 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.

  5. 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.

  6. 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.

  7. Structural origins of intrinsic stress in amorphous silicon thin films

    E-Print Network [OSTI]

    Johlin, Eric (Eric Carl)

    Hydrogenated amorphous silicon (a-Si:H) refers to a broad class of atomic configurations, sharing a lack of long-range order, but varying significantly in material properties, including optical constants, porosity, hydrogen ...

  8. Understanding and improving hole transport in hydrogenated amorphous silicon photovoltaics

    E-Print Network [OSTI]

    Johlin, Eric (Eric Carl)

    2014-01-01T23:59:59.000Z

    While hydrogenated amorphous silicon (a-Si:H) solar cells have been studied extensively for the previous four decades, the low performance of the devices is still not well understood. The poor efficiency (below 10%, even ...

  9. 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 . . . . . . . . . . .

  10. Hydrogenated Nanocrystalline Silicon p-Layer in a-Si:H n-i-p Solar Cells Wenhui Dua)

    E-Print Network [OSTI]

    Deng, Xunming

    Hydrogenated Nanocrystalline Silicon p-Layer in a-Si:H n-i-p Solar Cells Wenhui Dua) , Xianbo Liaob hydrogenated amorphous silicon (a-Si:H) solar cells. Raman scattering spectroscopy and transmission electron). Using this kind of p-layer in n-i-p a-Si:H solar cells, the cell performances were improved with a Voc

  11. FINE-GRAINED NANOCRYSTALLINE SILICON P-LAYER FOR HIGH OPEN CIRCUIT VOLTAGE A-SI:H SOLAR CELLS

    E-Print Network [OSTI]

    Deng, Xunming

    FINE-GRAINED NANOCRYSTALLINE SILICON P-LAYER FOR HIGH OPEN CIRCUIT VOLTAGE A-SI:H SOLAR CELLS of Michigan, Ann Arbor, MI 48109, USA ABSTRACT Hydrogenated amorphous silicon (a-Si:H) single- junction solar). It is found that the p-layer that leads to high Voc a-Si:H solar cells is a mixed-phase material that contains

  12. 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.

  13. 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.

  14. 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...

  15. High resolution amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Kaplan, S.N.; Perez-Mendez, V.

    1992-05-26T23:59:59.000Z

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n-type, intrinsic, p-type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography. 18 figs.

  16. High resolution amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Kaplan, Selig N. (El Cerrito, CA); Perez-Mendez, Victor (Berkeley, CA)

    1992-01-01T23:59:59.000Z

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n type, intrinsic, p type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography.

  17. 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.

  18. Amorphous silicon thin film transistor as nonvolatile device. 

    E-Print Network [OSTI]

    Nominanda, Helinda

    2008-10-10T23:59:59.000Z

    n-channel and p-channel amorphous-silicon thin-film transistors (a-Si:H TFTs) with copper electrodes prepared by a novel plasma etching process have been fabricated and studied. Their characteristics are similar to those of TFTs with molybdenum...

  19. 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.

  20. Boron-doped amorphous diamondlike carbon as a new p-type window material in amorphous silicon p-i-n solar cells

    E-Print Network [OSTI]

    Kim, Yong Jung

    -i-n solar cells Chang Hyun Lee and Koeng Su Lim Department of Electrical Engineering, Korea Advanced this film, amorphous silicon (a-Si solar cells with a novel p-a-DLC:H/p-a-SiC double p-layer structure were as window materials for amorphous silicon (a-Si based solar cells.1­4 In using such films as a p layer

  1. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    decline in photovoltaic efficiency is less dramatic, butefficiency ? = V OC I ?j SC Amorphous Silicon-Carbon Nanostructure So- lar Cells For this thesis, I made photovoltaic

  2. 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

  3. 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...

  4. 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...

  5. 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...

  6. amorphous silicon pv: 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. amorphous silicon tft: 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 20 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  17. 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...

  18. 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...

  19. 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...

  20. amorphous silicon surfaces: 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...

  1. amorphous silicon technology: Topics by E-print Network

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

    technologies is presented. Then 11 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  2. amorphous silicon electronic: Topics by E-print Network

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

    technologies is presented. Then 22 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  3. amorphous silicon dioxide: 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 8 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  4. amorphous silicon oxynitride: 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 15 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  5. amorphous silicon schottky: 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 13 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  6. amorphous silicon nitride: Topics by E-print Network

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

    Paris-Sud XI, Universit de 26 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  7. amorphous silicon layers: 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 16 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  8. amorphous silicon detector: 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...

  9. area amorphous silicon: 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...

  10. amorphous silicon measured: 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 13 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  11. amorphous silicon deposited: 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 23 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  12. amorphous silicon flat: 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...

  13. 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...

  14. amorphous silicon sensors: 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...

  15. amorphous silicon carbonitride: 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...

  16. amorphous silicon research: 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...

  17. amorphous silicon prepared: Topics by E-print Network

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

    Nominanda, Helinda 2008-10-10 10 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  18. amorphous silicon microdisk: 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 24 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  19. amorphous silicon germanium: Topics by E-print Network

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

    (Si-I or Ge Wang, Wei Hua 37 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  20. amorphous silicon radiation: 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...

  1. amorphous silicon multijunction: 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...

  2. amorphous silicon pixel: Topics by E-print Network

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    Ph. Emplit; S. Massar 2011-02-04 14 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  3. Deng & Schiff, Amorphous Silicon Based Solar Cells rev. 7/30/2002, Page 1 Amorphous Silicon Based Solar Cells

    E-Print Network [OSTI]

    Deng, Xunming

    Deng & Schiff, Amorphous Silicon Based Solar Cells rev. 7/30/2002, Page 1 Amorphous Silicon Based Solar Cells Xunming Deng and Eric A. Schiff Table of Contents 1 Overview 3 1.1 Amorphous Silicon: The First Bipolar Amorphous Semiconductor 3 1.2 Designs for Amorphous Silicon Solar Cells: A Guided Tour 6

  4. Compensated amorphous-silicon solar cell

    DOE Patents [OSTI]

    Devaud, G.

    1982-06-21T23:59:59.000Z

    An amorphous silicon solar cell including an electrically conductive substrate, a layer of glow discharge deposited hydrogenated amorphous silicon 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 elecrically 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.

  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. Deposition of device quality low H content, amorphous silicon films

    DOE Patents [OSTI]

    Mahan, A.H.; Carapella, J.C.; Gallagher, A.C.

    1995-03-14T23:59:59.000Z

    A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH{sub 4}) over a high temperature, 2,000 C, tungsten (W) filament in the proximity of a high temperature, 400 C, substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20--30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content. 7 figs.

  7. Deposition of device quality low H content, amorphous silicon films

    DOE Patents [OSTI]

    Mahan, Archie H. (Golden, CO); Carapella, Jeffrey C. (Evergreen, CO); Gallagher, Alan C. (Louisville, CO)

    1995-01-01T23:59:59.000Z

    A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH.sub.4) over a high temperature, 2000.degree. C., tungsten (W) filament in the proximity of a high temperature, 400.degree. C., substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20-30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content.

  8. amorphous silicon thin-film: Topics by E-print Network

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

    amorphous silicon Kanicki, Jerzy 17 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  9. Amorphization of Silicon Carbide by Carbon Displacement. | EMSL

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

    plays a significant role in the amorphization. Citation: Devanathan R, F Gao, and WJ Weber.2004."Amorphization of Silicon Carbide by Carbon Displacement."Applied Physics Letters...

  10. Temperature dependent deformation mechanisms in pure amorphous silicon

    SciTech Connect (OSTI)

    Kiran, M. S. R. N., E-mail: kiran.mangalampalli@anu.edu.au; Haberl, B.; Williams, J. S.; Bradby, J. E. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

    2014-03-21T23:59:59.000Z

    High temperature nanoindentation has been performed on pure ion-implanted amorphous silicon (unrelaxed a-Si) and structurally relaxed a-Si to investigate the temperature dependence of mechanical deformation, including pressure-induced phase transformations. Along with the indentation load-depth curves, ex situ measurements such as Raman micro-spectroscopy and cross-sectional transmission electron microscopy analysis on the residual indents reveal the mode of deformation under the indenter. While unrelaxed a-Si deforms entirely via plastic flow up to 200?°C, a clear transition in the mode of deformation is observed in relaxed a-Si with increasing temperature. Up to 100?°C, pressure-induced phase transformation and the observation of either crystalline (r8/bc8) end phases or pressure-induced a-Si occurs in relaxed a-Si. However, with further increase of temperature, plastic flow rather than phase transformation is the dominant mode of deformation. It is believed that the elevated temperature and pressure together induce bond softening and “defect” formation in structurally relaxed a-Si, leading to the inhibition of phase transformation due to pressure-releasing plastic flow under the indenter.

  11. Structure of amorphous silicon and germanium alloy films

    SciTech Connect (OSTI)

    Norberg, R.E.; Fedders, P.A. (Washington Univ., St. Louis, MO (USA))

    1991-07-01T23:59:59.000Z

    The primary objective of the research is to improve the understanding at the microscopic level of amorphous silicon and germanium film structures deposited under various methods. The work is to correlate and theoretically analyze, nuclear magnetic resonance, NMR, ESR, electron spin resonance, and other measurements. The alloys of concern include those obtained by adding dopants to hydrogenated silicon and germanium. The work has been directed to continue deuteron magnetic resonance DMR studies and to pay particulate attention to those structural features which may correlate with the photoelectronic properties of the material. The 1990 (DMR) accomplishments have included correlation of inhomogeneous nuclear spin relaxation with photovoltaic quality. In a second project, a structural rearrangement of atoms has been demonstrated to be associated with the light-induced metastability in a-Si:D, H films. A third approach has employed proton-deuteron coupled spin dynamics to examine hydrogen and deuterium motions in quality films of a-Si:H; a-Si:P,H; and a-Si:D,H. The B- P-doped films show a significantly enhanced hydrogen mobility above 200 K. We also have performed a number of detailed calculations on the effects coordination and strain on the deep electronic states rising from B and P dopants in a-Si as well as the band tail states in the gap of a-Si arising from strained bonds. This work gives a rather complete picture of the effects on the gap states of strain and dopants in the absence of H and for a given configuration of the a-Si network. We conclude that the methods that we have developed over the past three years are capable of describing many of the effects of strained bonds, especially their effect on dopants. 25 refs., 11 figs., 3 tabs.

  12. Fabricating amorphous silicon solar cells by varying the temperature _of the substrate during deposition of the amorphous silicon layer

    DOE Patents [OSTI]

    Carlson, David E. (Yardley, PA)

    1982-01-01T23:59:59.000Z

    An improved process for fabricating amorphous silicon solar cells in which the temperature of the substrate is varied during the deposition of the amorphous silicon layer is described. Solar cells manufactured in accordance with this process are shown to have increased efficiencies and fill factors when compared to solar cells manufactured with a constant substrate temperature during deposition of the amorphous silicon layer.

  13. Metal electrode for amorphous silicon solar cells

    DOE Patents [OSTI]

    Williams, Richard (Princeton, NJ)

    1983-01-01T23:59:59.000Z

    An amorphous silicon solar cell having an N-type region wherein the contact to the N-type region is composed of a material having a work function of about 3.7 electron volts or less. Suitable materials include strontium, barium and magnesium and rare earth metals such as gadolinium and yttrium.

  14. Study of plasma enhanced chemical vapor deposition of boron-doped hydrogenated amorphous silicon thin films and the application to p-channel thin film transistor

    E-Print Network [OSTI]

    Nominanda, Helinda

    2004-01-01T23:59:59.000Z

    The material and process characteristics of boron doped hydrogenated amorphous silicon (a-Si:H) thin film deposited by plasma enhanced chemical vapor deposition technique (PECVD) have been studied. The goal is to apply the high quality films...

  15. Atomistic modeling of amorphous silicon carbide using a bond...

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

    there is partial recovery of shortrange order. Citation: Devanathan R, F Gao, and WJ Weber.2007."Atomistic modeling of amorphous silicon carbide using a bond-order...

  16. Irradiation-induced defect clustering and amorphization in silicon...

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

    guidance on experimental approaches to reveal the onset of these processes. Citation: Weber WJ, and F Gao.2010."Irradiation-induced defect clustering and amorphization in silicon...

  17. Crystallization and doping of amorphous silicon on low temperature plastic

    DOE Patents [OSTI]

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

    1994-09-13T23:59:59.000Z

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

  18. Crystallization and doping of amorphous silicon on low temperature plastic

    DOE Patents [OSTI]

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

    1994-01-01T23:59:59.000Z

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

  19. 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.

  20. Hydrogen plasma enhanced crystallization of hydrogenated amorphous silicon films

    E-Print Network [OSTI]

    Hydrogen plasma enhanced crystallization of hydrogenated amorphous silicon films K. Pangal,a) J. C August 1998; accepted for publication 21 October 1998 We report that a room temperature hydrogen plasma thermal crystallization of amorphous silicon time by a factor of five. Exposure to hydrogen plasma reduces

  1. Superlattice doped layers for amorphous silicon photovoltaic cells

    DOE Patents [OSTI]

    Arya, Rajeewa R. (Doylestown, PA)

    1988-01-12T23:59:59.000Z

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

  2. Method for improving the stability of amorphous silicon

    DOE Patents [OSTI]

    Branz, Howard M.

    2004-03-30T23:59:59.000Z

    A method of producing a metastable degradation resistant amorphous hydrogenated silicon film is provided, which comprises the steps of growing a hydrogenated amorphous silicon film, the film having an exposed surface, illuminating the surface using an essentially blue or ultraviolet light to form high densities of a light induced defect near the surface, and etching the surface to remove the defect.

  3. The structure of electronic states in amorphous silicon

    E-Print Network [OSTI]

    Drabold, David

    the structure and dynamics of electron states in amorphous Si. The nature of the states near the gap at zeroThe structure of electronic states in amorphous silicon David A. Drabold,* Uwe Stephan, Jianjun for amorphous Si, which are of particular interest for efficient ab initio calculation of electronic properties

  4. Unexpected short- and medium-range atomic structure of sputtered amorphous silicon upon thermal annealing

    SciTech Connect (OSTI)

    Haberl, B.; McKerracher, I.; Ruffell, S.; Williams, J. S.; Bradby, J. E. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Bogle, S. N.; Li, T.; Abelson, J. R. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Munroe, P. [Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052 (Australia)

    2011-11-01T23:59:59.000Z

    We investigate the structure of magnetron-sputtered (MS) amorphous silicon (a-Si) prepared under standard deposition conditions and compare this to pure ion-implanted (II) a-Si. The structure of both films is characterized in their as-prepared and thermally annealed states. Significant differences are observed in short- and medium-range order following thermal annealing. Whereas II a-Si undergoes structural relaxation toward a continuous random network, MS a-Si exhibits little change. Cross-sectional transmission electron microscopy reveals the presence of nanopores in the MS film consistent with reduced mass-density. Therefore, the short- and medium-range order of annealed, MS a-Si is tentatively attributed to these pores.

  5. RF Sputtering for preparing substantially pure amorphous silicon monohydride

    DOE Patents [OSTI]

    Jeffrey, Frank R. (Ames, IA); Shanks, Howard R. (Ames, IA)

    1982-10-12T23:59:59.000Z

    A process for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicon produced by reactive rf sputtering of an amorphous silicon target. There is provided a chamber with an amorphous silicon target and a substrate therein with the substrate and the target positioned such that when rf power is applied to the target the substrate is in contact with the sputtering plasma produced thereby. Hydrogen and argon are fed to the chamber and the pressure is reduced in the chamber to a value sufficient to maintain a sputtering plasma therein, and then rf power is applied to the silicon target to provide a power density in the range of from about 7 watts per square inch to about 22 watts per square inch to sputter an amorphous silicon hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

  6. 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

  7. HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X. Xiang and X. Deng

    E-Print Network [OSTI]

    Deng, Xunming

    HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X ABSTRACT We report high-efficiency single-junction a-SiGe n-i-p solar cells deposited using rf PECVD-area efficiencies have been improved to 12.5-13.0% and 10.4%, respectively, for 0.25 cm 2 a-SiGe cells

  8. Approximate ab initio calculations of electronic structure of amorphous silicon M. Durandurdu, D. A. Drabold, and N. Mousseau

    E-Print Network [OSTI]

    Drabold, David

    Approximate ab initio calculations of electronic structure of amorphous silicon M. Durandurdu, D. A the right electronic picture of a-Si is the limited availability of high quality structural mod- els. Models that structural and dynamical characteristics of such a model are reliable. This is because some

  9. ULTRA-LIGHTWEIGHT AMORPHOUS SILICON SOLAR CELLS DEPOSITED OIN 7.5pn-1 THICK STAINLESS STEEL SUBSTRATES

    E-Print Network [OSTI]

    Deng, Xunming

    ULTRA-LIGHTWEIGHT AMORPHOUS SILICON SOLAR CELLS DEPOSITED OIN 7.5pn-1 THICK STAINLESS STEEL specific power for space application, we deposited a-Si thin film solar cells on ultra-thin stainless steel-thin stainless steel (SS) substrates (down to 7.5 pm) for space power applications. In this paper, we report our

  10. Polycrystalline Silicon Solar Cells Fabricated by Pulsed Rapid Thermal Annealing of Amorphous Silicon 

    E-Print Network [OSTI]

    Lee, I-Syuan

    2014-05-07T23:59:59.000Z

    optimized. The novel nickel-induced crystallization with low thermal budget was demonstrated. Polycrystalline silicon thin films were formed from the amorphous silicon thin films by the pulsed rapid thermal annealing process enhanced with a thin nickel...

  11. Transmissive metallic contact for amorphous silicon solar cells

    DOE Patents [OSTI]

    Madan, A.

    1984-11-29T23:59:59.000Z

    A transmissive metallic contact for amorphous silicon semiconductors includes a thin layer of metal, such as aluminum or other low work function metal, coated on the amorphous silicon with an antireflective layer coated on the metal. A transparent substrate, such as glass, is positioned on the light reflective layer. The metallic layer is preferably thin enough to transmit at least 50% of light incident thereon, yet thick enough to conduct electricity. The antireflection layer is preferably a transparent material that has a refractive index in the range of 1.8 to 2.2 and is approximately 550A to 600A thick.

  12. Hydrogenated Amorphous Silicon Sensor Deposited on Integrated Circuit for Radiation Detection

    E-Print Network [OSTI]

    Despeisse, M; Jarron, P; Kaplon, J; Moraes, D; Nardulli, A; Powolny, F; Wyrsch, N

    2008-01-01T23:59:59.000Z

    Radiation detectors based on the deposition of a 10 to 30 mum thick hydrogenated amorphous silicon (a-Si:H) sensor directly on top of integrated circuits have been developed. The performance of this detector technology has been assessed for the first time in the context of particle detectors. Three different circuits were designed in a quarter micron CMOS technology for these studies. The so-called TFA (Thin-Film on ASIC) detectors obtained after deposition of a-Si:H sensors on the developed circuits are presented. High internal electric fields (104 to 105 V/cm) can be built in the a-Si:H sensor and overcome the low mobility of electrons and holes in this amorphous material. However, the deposited sensor's leakage current at such fields turns out to be an important parameter which limits the performance of a TFA detector. Its detailed study is presented as well as the detector's pixel segmentation. Signal induction by generated free carrier motion in the a-Si:H sensor has been characterized using a 660 nm pul...

  13. Latent ion tracks in amorphous silicon

    SciTech Connect (OSTI)

    Bierschenk, Thomas [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Giulian, Raquel [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Afra, Boshra [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Rodriguez, Matias D [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Schauries, D [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Mudie, Stephen [Australian Synchrotron] [Australian Synchrotron; Pakarinen, Olli H [ORNL] [ORNL; Djurabekova, Flyura [University of Helsinki] [University of Helsinki; Nordlund, Kai [University of Helsinki] [University of Helsinki; Osmani, Orkhan [University of Duisburg-Essen, Germany] [University of Duisburg-Essen, Germany; Medvedev, Nikita [University of Kaiserslautern, Germany] [University of Kaiserslautern, Germany; Rethfield, Baerbel [University of Kaiserslautern, Germany] [University of Kaiserslautern, Germany; Ridgway, Mark C [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Kluth, Patrick [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia

    2013-01-01T23:59:59.000Z

    We present experimental evidence for the formation of ion tracks in amorphous Si induced by swift heavy ion irradiation. An underlying core-shell structure consistent with remnants of a high density liquid structure was revealed by small-angle x-ray scattering and molecular dynamics simulations. Ion track dimensions dier for as-implanted and relaxed Si as attributed to dierent microstructures and melting temperatures. The identication and characterisation of ion tracks in amorphous Si yields new insight into mechanisms of damage formation due to swift heavy ion irradiation in amorphous semiconductors.

  14. Inductively Coupled Plasma etching of amorphous silicon nanostructures over nanotopography using C4F8/SF6 chemistry

    E-Print Network [OSTI]

    Harvey-Collard, Patrick; Drouin, Dominique; Pioro-Ladrière, Michel; 10.1016/j.mee.2013.02.099

    2013-01-01T23:59:59.000Z

    Inductively Coupled Plasma (ICP) etching of amorphous silicon (a-Si) nanostructures using a continuous C4F8/SF6 plasma over nanotopography in silicon dioxide (SiO2) is investigated. The coil power of the ICP system is used to tune the a-Si etch rate from 20 to 125 nm/min. The etch rates of a-Si, SiO2 and electroresist are measured depending on the SF6 ratio, platen power and chamber pressure and used to optimize the a-Si:SiO2 etch selectivity. The results on nanostructures show that the presence of an insulating etch-stop layer affects the passivation ratio required to achieve vertical sidewalls. A low pressure is also necessary in order to etch the silicon nanostructure embedded into the oxide nanotrenches to form a highly conformable a-Si nanowire. We argue that both of these behaviors could be explained by surface charging effects. Finally, etching of 20 nm a-Si nanowires that cross 15 nm trenches in oxide with vertical sidewalls and a 4.3:1 a-Si:SiO2 etch selectivity is demonstrated. This etching process ...

  15. 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

  16. 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.

  17. High-Efficiency Amorphous Silicon Alloy Based Solar Cells and Modules; Final Technical Progress Report, 30 May 2002--31 May 2005

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.

    2005-10-01T23:59:59.000Z

    The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low manufacturing cost and high reliability. Our strategy has been to use the spectrum-splitting triple-junction structure, a-Si:H/a-SiGe:H/a-SiGe:H, to improve solar cell and module efficiency, stability, and throughput of production. The methodology used to achieve the objectives included: (1) explore the highest stable efficiency using the triple-junction structure deposited using RF glow discharge at a low rate, (2) fabricate the devices at a high deposition rate for high throughput and low cost, and (3) develop an optimized recipe using the R&D batch large-area reactor to help the design and optimization of the roll-to-roll production machines. For short-term goals, we have worked on the improvement of a-Si:H and a-SiGe:H alloy solar cells. a-Si:H and a-SiGe:H are the foundation of current a-Si:H based thin-film photovoltaic technology. Any improvement in cell efficiency, throughput, and cost reduction will immediately improve operation efficiency of our manufacturing plant, allowing us to further expand our production capacity.

  18. Photocharge transport and recombination measurements in amorphous silicon films and solar cells by photoconductive frequency mixing. Annual subcontract report, May 13, 1994--May 12, 1995

    SciTech Connect (OSTI)

    Braunstein, R.; Yang, Y.; Dong, S. [Univ. of California, Los Angeles, CA (United States)] [Univ. of California, Los Angeles, CA (United States)

    1995-10-01T23:59:59.000Z

    The continuous decay of electron drift mobility in intrinsic a-Si:H and a-SiC:H upon light soaking was investigated by the photomixing technique. The photoconductivity, lifetime and drift mobility in intrinsic hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous silicon carbide (a-SiC:H) while light-soaking were determined using a photomixing technique. In addition to the decay of the photoconductivity and electron lifetime, continuous decay of the electron drift mobility was found during the light soaking process, which reveals a new phenomenon associated with the Staebler-Wronski effect. The drift mobility decreased by a factor of 2 for 20 hour light soaking at 2.5 sun intensity. Experimental data were fitted to a stretched exponential law. Different stretched-exponential parameters for photoconductivity, lifetime and drift mobility were obtained, which indicates the production of defects with different generation kinetics upon light soaking.

  19. Anti-reflection zinc oxide nanocones for higher efficiency thin-film silicon solar cells

    E-Print Network [OSTI]

    Mailoa, Jonathan P

    2012-01-01T23:59:59.000Z

    Thin film silicon solar cells, which are commonly made from microcrystalline silicon ([mu]c-Si) or amorphous silicon (a-Si), have been considered inexpensive alternatives to thick polycrystalline silicon (polysilicon) solar ...

  20. Improved method of preparing p-i-n junctions in amorphous silicon semiconductors

    DOE Patents [OSTI]

    Madan, A.

    1984-12-10T23:59:59.000Z

    A method of preparing p/sup +/-i-n/sup +/ junctions for amorphous silicon semiconductors includes depositing amorphous silicon on a thin layer of trivalent material, such as aluminum, indium, or gallium at a temperature in the range of 200/sup 0/C to 250/sup 0/C. At this temperature, the layer of trivalent material diffuses into the amorphous silicon to form a graded p/sup +/-i junction. A layer of n-type doped material is then deposited onto the intrinsic amorphous silicon layer in a conventional manner to finish forming the p/sup +/-i-n/sup +/ junction.

  1. amorphous silicon flat-panel: Topics by E-print Network

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

    5 Asymmetric Electrical Properties of Half Corbino Hydrogenated Amorphous Silicon Thin-Film Transistor and Its Applications to Flat Panel Displays Materials Science...

  2. High spatial resolution radiation detectors based on hydrogenated amorphous silicon and scintillator

    SciTech Connect (OSTI)

    Jing, T [Univ. of California, Berkeley, CA (United States). Dept. of Engineering-Nuclear Engineering

    1995-05-01T23:59:59.000Z

    Hydrogenated amorphous silicon (a-Si:H) as a large-area thin film semiconductor with ease of doping and low-cost fabrication capability has given a new impetus to the field of imaging sensors; its high radiation resistance also makes it a good material for radiation detectors. In addition, large-area microelectronics based on a-Si:H or polysilicon can be made with full integration of peripheral circuits, including readout switches and shift registers on the same substrate. Thin a-Si:H p-i-n photodiodes coupled to suitable scintillators are shown to be suitable for detecting charged particles, electrons, and X-rays. The response speed of CsI/a-Si:H diode combinations to individual particulate radiation is limited by the scintillation light decay since the charge collection time of the diode is very short (< 10ns). The reverse current of the detector is analyzed in term of contact injection, thermal generation, field enhanced emission (Poole-Frenkel effect), and edge leakage. A good collection efficiency for a diode is obtained by optimizing the p layer of the diode thickness and composition. The CsI(Tl) scintillator coupled to an a-Si:H photodiode detector shows a capability for detecting minimum ionizing particles with S/N {approximately}20. In such an arrangement a p-i-n diode is operated in a photovoltaic mode (reverse bias). In addition, a p-i-n diode can also work as a photoconductor under forward bias and produces a gain yield of 3--8 for shaping times of 1 {micro}s. The mechanism of the formation of structured CsI scintillator layers is analyzed. Initial nucleation in the deposited layer is sensitive to the type of substrate medium, with imperfections generally catalyzing nucleation. Therefore, the microgeometry of a patterned substrate has a significant effect on the structure of the CsI growth.

  3. {sup 1}H NMR electron-nuclear cross relaxation in thin films of hydrogenated amorphous silicon

    SciTech Connect (OSTI)

    Su Tining; Taylor, P. C.; Ganguly, G.; Carlson, D. E.; Bobela, D. C.; Hari, P. [Department of Physics, Colorado School of Mines, Golden, Colorado 80401 (United States); BP Solar, Toano, Virginia 23168 (United States); Department of Physics, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Physics and Engineering Physics, University of Tulsa, Tulsa, Oklahoma 74104 (United States)

    2007-12-15T23:59:59.000Z

    We investigate the spin-lattice relaxation of the dipolar order in {sup 1}H NMR in hydrogenated amorphous silicon (a-Si:H). We find that the relaxation is dominated by the cross relaxation between the hydrogen nuclei and the paramagnetic states. The relaxation is inhomogeneous, and can be described as a stretched exponential function. We proposed a possible mechanism for this relaxation. This mechanism applies to a rather broad range of paramagnetic states, including the deep neutral defects (dangling bonds), the light-induced metastable defects, the defects created by doping, and the singly occupied, localized band-tail states populated by light at low temperatures. The cross relaxation is only sensitive to the bulk spin density, and the surface spins have a negligible effect on the relaxation.

  4. Enhanced electrochemical etching of ion irradiated silicon by localized amorphization

    SciTech Connect (OSTI)

    Dang, Z. Y.; Breese, M. B. H. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore Singapore 117542 (Singapore); Lin, Y.; Tok, E. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Vittone, E. [Physics Department, NIS Excellence Centre and CNISM, University of Torino, via Pietro Giuria 1, 10125 Torino (Italy)

    2014-05-12T23:59:59.000Z

    A tailored distribution of ion induced defects in p-type silicon allows subsequent electrochemical anodization to be modified in various ways. Here we describe how a low level of lattice amorphization induced by ion irradiation influences anodization. First, it superposes a chemical etching effect, which is observable at high fluences as a reduced height of a micromachined component. Second, at lower fluences, it greatly enhances electrochemical anodization by allowing a hole diffusion current to flow to the exposed surface. We present an anodization model, which explains all observed effects produced by light ions such as helium and heavy ions such as cesium over a wide range of fluences and irradiation geometries.

  5. Research on stable, high-efficiency, large-area, amorphous-silicon-based submodules

    SciTech Connect (OSTI)

    Delahoy, A.E.; Tonon, T.; Macneil, J. (Chronar Corp., Princeton, NJ (USA))

    1991-06-01T23:59:59.000Z

    The primary objective of this subcontract is to develop the technology for same bandgap, amorphous silicon tandem junction photovoltaic modules having an area of at least 900 cm{sup 2} with the goal of achieving an aperture area efficiency of 9%. A further objective is to demonstrate modules that retain 95% of their under standard light soaking conditions. Our approach to the attainment of these objective is based on the following distinctive technologies: (a) in-house deposition of SiO{sub 2}/SnO{sub 2}:F onto soda lime glass by APCVD to provide a textured, transparent electrode, (b) single chamber r.f. flow discharge deposition of the a-Si:H layers onto vertical substrates contained with high package density in a box carrier'' to which the discharge is confined (c) sputter deposition of highly reflecting, ZnO-based back contacts, and (d) laser scribing of the a-Si:H and electrodes with real-time scribe tracking to minimize area loss. Continued development of single junction amorphous silicon was aggressively pursued as proving ground for various optical enhancement schemes, new p-layers, and i-layers quality. We have rigorously demonstrated that the introduction of a transitional i-layer does not impair stability and that the initial gain in performance is retained. We have demonstrated a small improvement in cell stability through a post-fabrication treatment consisting of multiple, intense light flashes followed by sufficient annealing. Finally, several experiments have indicated that long term stability can be improved by overcoating the SnO{sub 2} with ZnO. 25 refs., 17 figs.

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

    E-Print Network [OSTI]

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

  7. An optical gap calibration applied to the case of hydrogenated amorphous silicon

    SciTech Connect (OSTI)

    Sweenor, D.E.; O'Leary, S.K.; Foutz, B.E.

    1999-07-01T23:59:59.000Z

    There are many different empirical means whereby the optical gap of an amorphous semiconductor may be defined. They analyze some hydrogenated amorphous silicon data with respect to a number of these empirical measures for the optical gap. By plotting these various gap measures as a function of the breadth of the optical absorption tail, they provide a means of relating these disparate measures of the optical gap. The applicability of this calibration to another set of hydrogenated amorphous silicon data is investigated.

  8. The specific heat of pure and hydrogenated amorphous silicon

    E-Print Network [OSTI]

    Queen, Daniel Robert

    2011-01-01T23:59:59.000Z

    of of a-Si:H photovoltaics to 10% efficiency. However, a-Si:a-Si:H) photovoltaics undergo a loss in efficiency upon

  9. Deposition of device quality, low hydrogen content, amorphous silicon films by hot filament technique using ``safe`` silicon source gas

    DOE Patents [OSTI]

    Mahan, A.H.; Molenbroek, E.C.; Nelson, B.P.

    1998-07-07T23:59:59.000Z

    A method is described for producing hydrogenated amorphous silicon on a substrate by flowing a stream of safe (diluted to less than 1%) silane gas past a heated filament. 7 figs.

  10. See-through amorphous silicon solar cells with selectively transparent and conducting photonic crystal back reflectors for building integrated photovoltaics

    SciTech Connect (OSTI)

    Yang, Yang [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Room GB254B, Toronto, Ontario M5S 3G4 (Canada)] [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Room GB254B, Toronto, Ontario M5S 3G4 (Canada); O’Brien, Paul G. [Department of Materials Science and Engineering, University of Toronto, 184 College Street, Room 140, Toronto, Ontario M5S 3E4 (Canada) [Department of Materials Science and Engineering, University of Toronto, 184 College Street, Room 140, Toronto, Ontario M5S 3E4 (Canada); Materials Chemistry Research Group, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada); Ozin, Geoffrey A., E-mail: gozin@chem.utoronto.ca, E-mail: kherani@ecf.utoronto.ca [Materials Chemistry Research Group, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada); Kherani, Nazir P., E-mail: gozin@chem.utoronto.ca, E-mail: kherani@ecf.utoronto.ca [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Room GB254B, Toronto, Ontario M5S 3G4 (Canada); Department of Materials Science and Engineering, University of Toronto, 184 College Street, Room 140, Toronto, Ontario M5S 3E4 (Canada)

    2013-11-25T23:59:59.000Z

    Thin semi-transparent hydrogenated amorphous silicon (a-Si:H) solar cells with selectively transparent and conducting photonic crystal (STCPC) back-reflectors are demonstrated. Short circuit current density of a 135?nm thick a-Si:H cell with a given STCPC back-reflector is enhanced by as much as 23% in comparison to a reference cell with an ITO film functioning as its rear contact. Concurrently, solar irradiance of 295?W/m{sup 2} and illuminance of 3480 lux are transmitted through the cell with a given STCPC back reflector under AM1.5 Global tilt illumination, indicating its utility as a source of space heating and lighting, respectively, in building integrated photovoltaic applications.

  11. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual subcontract report, April 1, 1994--March 31, 1995

    SciTech Connect (OSTI)

    Gordon, R.G. [Harvard Univ., Cambridge, MA (United States)

    1995-10-01T23:59:59.000Z

    Transparent and reflecting electrodes are important parts of the structure of amorphous silicon solar cells. We report improved methods for depositing zinc oxide, deposition of tin nitride as a potential reflection-enhancing diffusion barrier between the a-Si and back metal electrodes. Highly conductive and transparent fluorine-doped zinc oxide was successfully produced on small areas by atmospheric pressure CVD from a less hazardous zinc precursor, zinc acetylacetonate. The optical properties measured for tin nitride showed that the back-reflection would be decreased if tin nitride were used instead of zinc oxide as a barrier layer over silver on aluminum. Niobium-doped titanium dioxide was produced with high enough electrical conductivity so that normal voltages and fill factors were obtained for a-Si cells made on it.

  12. Amorphous silicon research. Final technical progress report, 1 August 1994--28 February 1998

    SciTech Connect (OSTI)

    Guha, S. [United Solar Systems Corp., Troy, MI (United States)] [United Solar Systems Corp., Troy, MI (United States)

    1998-05-01T23:59:59.000Z

    This report describes the status and accomplishments of work performed under this subcontract by United Solar Systems. United Solar researchers explored several new deposition regimes/conditions to investigate their effect on material/device performance. To facilitate optimum ion bombardment during growth, a large parameter space involving chamber pressure, rf power, and hydrogen dilution were investigated. United Solar carried out a series of experiments using discharge modulation at various pulsed-plasma intervals to study the effect of Si-particle incorporation on solar cell performance. Hydrogen dilution during deposition is found to improve both the initial and stable performance of a-Si and a-SiGe alloy cells. Researchers conducted a series of temperature-ramping experiments on samples prepared with high and low hydrogen dilutions to study the effect of hydrogen effusion on solar cell performance. Using an internal photoemission method, the electrical bandgap of a microcrystalline p layer used in high-efficiency solar cells was measured to be 1.6 eV. New measurement techniques were developed to evaluate the interface and bulk contributions of losses to solar cell performance. Researchers replaced hydrogen with deuterium and found deuterated amorphous silicon alloy solar cells exhibit reduced light-induced degradation. The incorporation of a microcrystalline n layer in a multijunction cell is seen to improve cell performance. United Solar achieved a world-record single-junction a-Si alloy stable cell efficiency of 9.2% with an active area of 0.25 cm{sup 2} grown with high hydrogen dilution. They also achieved a world-record triple-junction, stable, active-area cell efficiency of 13.0% with an active area of 0.25 cm{sup 2}.

  13. Amorphous silicon cell array powered solar tracking apparatus

    DOE Patents [OSTI]

    Hanak, Joseph J. (Lawrenceville, NJ)

    1985-01-01T23:59:59.000Z

    An array of an even number of amorphous silicon solar cells are serially connected between first and second terminals of opposite polarity. The terminals are connected to one input terminal of a DC motor whose other input terminal is connected to the mid-cell of the serial array. Vane elements are adjacent the end cells to selectively shadow one or the other of the end cells when the array is oriented from a desired attitude relative to the sun. The shadowing of one cell of a group of cells on one side of the mid-cell reduces the power of that group substantially so that full power from the group of cells on the other side of the mid-cell drives the motor to reorient the array to the desired attitude. The cell groups each have a full power output at the power rating of the motor. When the array is at the desired attitude the power output of the two groups of cells balances due to their opposite polarity so that the motor remains unpowered.

  14. Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells

    SciTech Connect (OSTI)

    Bullock, J., E-mail: james.bullock@anu.edu.au; Cuevas, A.; Yan, D. [Research School of Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Demaurex, B.; Hessler-Wyser, A.; De Wolf, S. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Micro Engineering (IMT), Photovoltaics and Thin Film Electronic Laboratory PVLab, Maladière 71b, CH-200 Neuchâtel (Switzerland)

    2014-10-28T23:59:59.000Z

    Carrier recombination at the metal-semiconductor contacts has become a significant obstacle to the further advancement of high-efficiency diffused-junction silicon solar cells. This paper provides the proof-of-concept of a procedure to reduce contact recombination by means of enhanced metal-insulator-semiconductor (MIS) structures. Lightly diffused n{sup +} and p{sup +} surfaces are passivated with SiO{sub 2}/a-Si:H and Al{sub 2}O{sub 3}/a-Si:H stacks, respectively, before the MIS contacts are formed by a thermally activated alloying process between the a-Si:H layer and an overlying aluminum film. Transmission/scanning transmission electron microscopy (TEM/STEM) and energy dispersive x-ray spectroscopy are used to ascertain the nature of the alloy. Idealized solar cell simulations reveal that MIS(n{sup +}) contacts, with SiO{sub 2} thicknesses of ?1.55?nm, achieve the best carrier-selectivity producing a contact resistivity ?{sub c} of ?3 m? cm{sup 2} and a recombination current density J{sub 0c} of ?40 fA/cm{sup 2}. These characteristics are shown to be stable at temperatures up to 350?°C. The MIS(p{sup +}) contacts fail to achieve equivalent results both in terms of thermal stability and contact characteristics but may still offer advantages over directly metallized contacts in terms of manufacturing simplicity.

  15. Status and future of government-supported amorphous silicon research in the United States

    SciTech Connect (OSTI)

    Wallace, W.L.; Sabisky, E.S.

    1986-06-01T23:59:59.000Z

    The Amorphous Silicon Research Project (ASRP) was established at the Solar Energy Research Institute in 1983 and is responsible for all US Department of Energy government supported research activities in the field of amorphous silicon photovoltaics. The objectives and research directions of the project have been established by a Five-Year Research Plan, which was developed at SERI in cooperation with the Department of Energy in 1984 and is divided into research on single-junction and multi-junction solar cells. DOE/SERI has recently initiated a new three year program to be performed in collaboration with US industry to perform work on high efficiency amorphous silicon solar cells and submodules. The objectives of this initiative are: (i) to achieve 18% efficiencies for small area multi-junction amorphous silicon cells, and (ii) to achieve amorphous silicon submodule efficiencies in the 10 to 13% range for single-junction and multi-junction submodule configurations over areas of at least 1000 cm/sup 2/.

  16. Photocharge Transport and Recombination Measurements in Amorphous Silicon Films and Solar Cells by Photoconductive Frequency Mixing: Final Subcontract Report: 13 May 1994 - 15 January 1998

    SciTech Connect (OSTI)

    Braunstein, R.; Tang, Y.; Dong, S.; Liebe, J.; Sun, G.; Kattwinkel, A. (University of California: Los Angeles, California)

    1999-05-04T23:59:59.000Z

    This report describes work performed during this subcontract by the University of California. The photoconductivity, lifetime, and drift mobility of intrinsic hydrogenated amorphous silicon (a-Si:H), hydrogenated amorphous silicon carbide (a-SiC:H), and hydrogenated amorphous silicon germanium (a-SiGe:H) were determined using a photomixing technique in the as prepared and light-soaked states. In addition to the decay of the photoconductivity and electron lifetime, continuous decay of the electron drift mobility was found during the light-soaking process (Staebler-Wronski effect). Experimental data were fitted to a stretched exponential law. Different stretched-exponential parameters for photoconductivity, lifetime, and drift mobility were obtained, which indicates the production of defects with different generation kinetics upon light soaking. The transport properties of intrinsic a-Si:H samples (which were produced by the hot-wire technique at NREL at different substrate temperatures such that the hydrogen content ranged from >10% to <1%), were systematically studied. It was found that with increasing substrate temperature, the lifetime, the drift mobility, and the photoconductivity decreased, but the Urbach energy ({approx} 0.1 eV below the conduction band) increased. These results indicate that for the a-Si:H films with increasing deposition temperature, the density of positively charged, negatively charged, and neutral defects all show a tendency to increase, in agreement with the results observed by other workers employing other measurement techniques. Researchers also found that the drift mobility of these samples increases and the lifetime decreases with increasing electric field, while the mt product is essentially independent of the electric field in the range of 1,000-10,000 V/cm. The electric field dependence of mobility (Dm) /m0/ (DE) in the as-grown or/and annealed states are always larger than that in the light-soaked state. This electric field dependence of mobility can be explained by the existence of long-range potential fluctuations. Photoemission measurements in air were performed on a-Si:H, a-SiC:H, and transparent conducting oxide layers, and revealed inhomogeneities of composition or surface contamination.

  17. Hydrogen dynamics and light-induced structural changes in hydrogenated amorphous silicon T. A. Abtew* and D. A. Drabold

    E-Print Network [OSTI]

    Drabold, David

    Hydrogen dynamics and light-induced structural changes in hydrogenated amorphous silicon T. A first-principles methods to study the network dynamics of hydrogenated amorphous silicon, including the motion of hydrogen. In addition to studies of atomic dynamics in the electronic ground state, we also

  18. Experimental determination of the distribution of tail states of hydrogenated amorphous silicon: A transient photocurrent analysis

    SciTech Connect (OSTI)

    Webb, D.P.; Chan, F.Y.M.; Zou, X.C.; Chan, Y.C.; Lam, Y.W.; Lin, S.H.; O'Leary, S.K.; Lim, P.K.

    1997-07-01T23:59:59.000Z

    Recent experimental developments have cast doubt on the validity of the common assumption that the distribution of tail states of hydrogenated amorphous silicon exhibits a single exponential functional form. The authors employ transient photocurrent decay measurements to determine this distribution of tail states. In their approach, however, they determine the distribution of tail states directly from the experimental data, without assuming, a priori, a specific functional form. It is found that these experimental results are consistent with other more recent experimental determinations of the distribution of tail states, suggesting the possibility of deviations from a single exponential distribution of tail states in hydrogenated amorphous silicon.

  19. Multi-resonant silver nano-disk patterned thin film hydrogenated amorphous silicon solar cells for Staebler-Wronski effect compensation

    E-Print Network [OSTI]

    Vora, Ankit; Pearce, Joshua M; Bergstrom, Paul L; Güney, Durdu Ö

    2014-01-01T23:59:59.000Z

    We study polarization independent improved light trapping in commercial thin film hydrogenated amorphous silicon (a-Si:H) solar photovoltaic cells using a three-dimensional silver array of multi-resonant nano-disk structures embedded in a silicon nitride anti-reflection coating (ARC) to enhance optical absorption in the intrinsic layer (i-a-Si:H) for the visible spectrum for any polarization angle. Predicted total optical enhancement (OE) in absorption in the i-a-Si:H for AM-1.5 solar spectrum is 18.51% as compared to the reference, and producing a 19.65% improvement in short-circuit current density (JSC) over 11.7 mA/cm2 for a reference cell. The JSC in the nano-disk patterned solar cell (NDPSC) was found to be higher than the commercial reference structure for any incident angle. The NDPSC has a multi-resonant optical response for the visible spectrum and the associated mechanism for OE in i-a-Si:H layer is excitation of Fabry-Perot resonance facilitated by surface plasmon resonances. The detrimental Staebl...

  20. 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

  1. Short Channel Amorphous-Silicon TFT's on High-Temperature Clear Plastic Substrates

    E-Print Network [OSTI]

    Short Channel Amorphous-Silicon TFT's on High-Temperature Clear Plastic Substrates K. Long, H@princeton.edu To achieve light-weight flexible AMOLED displays on plastic substrates, the substratesmust be optically clear for plastic. High-temperature plastics such as polyimide (e.g. KaptonB E) have a glass transition temperature

  2. Optimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell

    E-Print Network [OSTI]

    to bring down the cost of photovoltaic (PV) solar cells has gained huge momentum, and many strategiesOptimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell-wave approach was used to compute the plane-wave absorptance of a thin-film tandem solar cell with a metallic

  3. An efficient light trapping scheme based on textured conductive photonic crystal back reflector for performance improvement of amorphous silicon solar cells

    SciTech Connect (OSTI)

    Chen, Peizhuan; Hou, Guofu, E-mail: gfhou@nankai.edu.cn; Huang, Qian; Zhao, Jing; Zhang, Jianjun, E-mail: jjzhang@nankai.edu.cn; Ni, Jian; Zhang, Xiaodan; Zhao, Ying [Tianjin Key Laboratory of Photoelectronic Thin-Film Devices and Technique, Institute of Photoelectronics, Nankai University, Tianjin 300071 (China); Fan, QiHua [Department of Electrical Engineering and Computer Science, South Dakota State University, Brookings, South Dakota 57007 (United States)

    2014-08-18T23:59:59.000Z

    An efficient light trapping scheme named as textured conductive photonic crystal (TCPC) has been proposed and then applied as a back-reflector (BR) in n-i-p hydrogenated amorphous silicon (a-Si:H) solar cell. This TCPC BR combined a flat one-dimensional photonic crystal and a randomly textured surface of chemically etched ZnO:Al. Total efficiency enhancement was obtained thanks to the sufficient conductivity, high reflectivity and strong light scattering of the TCPC BR. Unwanted intrinsic losses of surface plasmon modes are avoided. An initial efficiency of 9.66% for a-Si:H solar cell was obtained with short-circuit current density of 14.74?mA/cm{sup 2}, fill factor of 70.3%, and open-circuit voltage of 0.932?V.

  4. amorphous silicon based: Topics by E-print Network

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

    The researchers have managed to create Rogers, John A. 279 A Silicon-Based Micro Gas Turbine Engine for Power Generation CERN Preprints Summary: This paper reports on our...

  5. amorphous silicon carbide: Topics by E-print Network

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

    The high power densities expected for the MIT microengine (silicon MEMS-based micro-gas turbine generator) require the turbine and compressor spool to rotate at a very high...

  6. Energy transfer and 1.54 m emission in amorphous silicon nitride films S. O. Kucheyev,2

    E-Print Network [OSTI]

    spectrometry RBS and high-resolution transmission electron microscopy HRTEM to quantify the amount of Si, NEnergy transfer and 1.54 m emission in amorphous silicon nitride films S. Yerci,1 R. Li,1 S. O a broad energy spectrum and attributed to disorder-induced localized transitions in amorphous Er

  7. Recombination and metastability in amorphous silicon and silicon germanium alloys. Annual subcontract report, 1 February 1991--31 January 1992

    SciTech Connect (OSTI)

    Silver, M. [North Carolina Univ., Chapel Hill, NC (United States)] [North Carolina Univ., Chapel Hill, NC (United States)

    1992-07-01T23:59:59.000Z

    This report describes the first year of a continuing research study to understand how recombination, trapping, and band-mobility modification affecting the electronic properties of amorphous semiconductors can be measured, characterized, and described by an appropriate spectrum of defect states, and how light-induced defects in a-Si:H and native defects in a-SiGe:H affect transport properties in these materials. The objective was to determine how the Staebler-Wronski defects affect the electronic processes in a-Si:H and a-SiGe:H films. To do this, electroluminescence (EL) and forward bias current in p-i-n devices (i-layer thickness > 2 {mu}m) were studied both experimentally and theoretically before and after light soaking. A simple picture was developed to compare forward bias current to the EL signal. The result was unexpected: the product of the final current times the rise time was not constant before and after light soaking as expected from the concept of gain band width, but instead changed radically. The rise time t{sub x} increased by more than one order of magnitude while the final current I{sub f} did not change significantly with light soaking. On the other hand the I{sub f}t{sub x} product did hold close to a constant when only the applied voltage changed.

  8. Research Progress in the DOE/SERI Amorphous Silicon Research Project

    SciTech Connect (OSTI)

    Sabisky, E.; Wallace, W.; Stafford, B.; Sadlon, K.; Luft, W.

    1985-04-01T23:59:59.000Z

    The Amorphous Silicon Research Project (ASRP), established at the Solar Energy Research Institute (SERI) in 1983, is responsible for all U.S. DOE government-supported research activities in the field of amorphous silicon photovoltaics. The objectives and research directions of the project have been established by a Five-Year Research Plan developed at SERI in cooperation with the Department of Energy in 1984. In order to accomplish project goals, research is performed by a combination of i) multi-year programs consisting of multi-disciplinary research teams based on strong government/industry partnerships and ii) basic research performed in university, government, and industrial laboratories. A summary of recent research progress in the ASRP program is presented.

  9. Polycrystalline Silicon Solar Cells Fabricated by Pulsed Rapid Thermal Annealing of Amorphous Silicon

    E-Print Network [OSTI]

    Lee, I-Syuan

    2014-05-07T23:59:59.000Z

    The PECVD intrinsic, n^(+), and p^(+) a-Si:H thin film deposition processes have been studied by the optical emission spectroscope to monitor the plasma phase chemistry. Process parameters, such as the plasma power, pressure, and gas flow rate...

  10. Buffer layers for narrow bandgap a-SiGe solar cells

    SciTech Connect (OSTI)

    Liao, X.B.; Walker, J.; Deng, X.

    1999-07-01T23:59:59.000Z

    In high efficiency narrow bandgap (NBG) a-SiGe solar cells, thin buffer layers of unalloyed hydrogenated amorphous silicon (a-Si) are usually used at the interfaces between the a-SiGe intrinsic layer and the doped layers. They investigated the effect of inserting additional a-SiGe interface layers between these a-Si buffer layers and the a-SiGe absorber layer. They found that such additional interface layers increase solar cell V{sub oc} and FF sizably, most likely due to the reduction or elimination of the abrupt bandgap discontinuity between the a-SiGe absorber layer and the a-Si buffer layers. With these improved narrow bandgap solar cells incorporated into the fabrication of triple-junction a-Si based solar cells, they obtained triple cells with initial efficiency of 10.6%.

  11. Energy transfer and 1.54 {mu}m emission in amorphous silicon nitride films

    SciTech Connect (OSTI)

    Yerci, S.; Li, R. [Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary's Street, Boston, Massachusetts 02215-2421 (United States); Kucheyev, S. O.; Buuren, T. van [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Basu, S. N. [Division of Materials Science and Engineering, Boston University, 15 Saint Mary's Street, Brookline, Massachusetts 02446 (United States); Department of Mechanical Engineering, Boston University, 110 Cummington Street, Boston, Massachusetts 02215 (United States); Dal Negro, L. [Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary's Street, Boston, Massachusetts 02215-2421 (United States); Division of Materials Science and Engineering, Boston University, 15 Saint Mary's Street, Brookline, Massachusetts 02446 (United States)

    2009-07-20T23:59:59.000Z

    Er-doped amorphous silicon nitride films with various Si concentrations (Er:SiN{sub x}) were fabricated by reactive magnetron cosputtering followed by thermal annealing. The effects of Si concentrations and annealing temperatures were investigated in relation to Er emission and excitation processes. Efficient excitation of Er ions was demonstrated within a broad energy spectrum and attributed to disorder-induced localized transitions in amorphous Er:SiN{sub x}. A systematic optimization of the 1.54 {mu}m emission was performed and a fundamental trade-off was discovered between Er excitation and emission efficiency due to excess Si incorporation. These results provide an alternative approach for the engineering of sensitized Si-based light sources and lasers.

  12. Study of the electronic properties of hydrogenated amorphous silicon films by femtosecond spectroscopy

    SciTech Connect (OSTI)

    Sevastyanov, M. G. [Kazan State Power Engineering University (Russian Federation)] [Kazan State Power Engineering University (Russian Federation); Lobkov, V. S.; Shmelev, A. G.; Leontev, A. V. [Russian Academy of Sciences, Zavoisky Physical Technical Institute, Kazan Research Center (Russian Federation)] [Russian Academy of Sciences, Zavoisky Physical Technical Institute, Kazan Research Center (Russian Federation); Matuhin, V. L. [Kazan State Power Engineering University (Russian Federation)] [Kazan State Power Engineering University (Russian Federation); Bobyl, A. V. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Terukov, E. I., E-mail: Eug.Terukov@mail.ioffe.ru [Russian Academy of Sciences, Zavoisky Physical Technical Institute, Kazan Research Center (Russian Federation); Kukin, A. V. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2013-10-15T23:59:59.000Z

    Experimental results on the electron relaxation time and diffusion coefficient in hydrogenated amorphous silicon films that exhibit intrinsic and electronic conductivity at room temperature are reported. It is found that, for these two types of films, the relaxation times are 1 ns and 465 ps and the diffusion coefficients are 0.54 and 0.83 cm{sup 2} s{sup -1}. It is established that, as the pulse intensity is increased, the decay time of the induced-grating signal shortens.

  13. Amorphous Silicon Solar cells with a Core-Shell Nanograting Structure

    E-Print Network [OSTI]

    Yang, L; Okuno, Y; He, S

    2011-01-01T23:59:59.000Z

    We systematically investigate the optical behaviors of an amorphous silicon solar cell based on a core-shell nanograting structure. The horizontally propagating Bloch waves and Surface Plasmon Polariton (SPP) waves lead to significant absorption enhancements and consequently short-circuit current enhancements of this structure, compared with the conventional planar one. The perpendicular carrier collection makes this structure optically thick and electronically thin. An optimal design is achieved through full-field numerical simulation, and physical explanation is given. Our numerical results show that this configuration has ultrabroadband, omnidirectional and polarization-insensitive responses, and has a great potential in photovoltaics.

  14. Hydex Glass and Amorphous Silicon for Integrated Nonlinear Optical Signal Processing

    E-Print Network [OSTI]

    Morandotti, Roberto

    2015-01-01T23:59:59.000Z

    Photonic integrated circuits that exploit nonlinear optics in order to generate and process signals all-optically have achieved performance far superior to that possible electronically - particularly with respect to speed. Although silicon-on-insulator has been the leading platform for nonlinear optics for some time, its high two-photon absorption at telecommunications wavelengths poses a fundamental limitation. We review the recent achievements based in new CMOS-compatible platforms that are better suited than SOI for nonlinear optics, focusing on amorphous silicon and Hydex glass. We highlight their potential as well as the challenges to achieving practical solutions for many key applications. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement.

  15. Measurment of Depositing and Bombarding Species Involved in the Plasma Production of Amorphous Silicon and Silicon/Germanium Solar Cells: Annual Technical Report, 1 June 2002 - 31 May 2005

    SciTech Connect (OSTI)

    Gallagher, A.; Rozsa, K.; Horvath, P.; Kujundcik, D.

    2006-06-01T23:59:59.000Z

    The objective of this study is to measure the molecular species that lead to the growth of hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (..mu..c-Si) photovoltaic (PV) devices from RF discharges. Neutral radicals produce most of the film growth during this PV-device production, and, by implication, radicals primarily determine the device structure and electrical characteristics. The most important feature of the present experiment is thus the measurement of neutral-radical fluxes to the substrate. Additional depositing species that can influence film properties are positive ions and silicon-based particles produced by the discharge; we also measure these positive-ion species here. Some studies have already measured some of these radical and positive-ion species in silane and silane/argon discharges, but not for discharge conditions similar to those used to produce most photovoltaic devices. Our objective is to measure all of these species for conditions typically used for device production. In particular, we have studied 13.6 MHz-excited discharges in pure silane and silane/hydrogen vapors.

  16. Network structure and dynamics of hydrogenated amorphous silicon D.A. Drabold *, T.A. Abtew, F. Inam, Y. Pan

    E-Print Network [OSTI]

    Drabold, David

    upon reasonable calculations of the electron-lattice coupling and molecular dynamic simulationNetwork structure and dynamics of hydrogenated amorphous silicon D.A. Drabold *, T.A. Abtew, F on the network or lattice dynamics of the system, both in the electronic ground state and in an electronic

  17. Microstructure factor and mechanical and electronic properties of hydrogenated amorphous and nanocrystalline silicon thin-films for microelectromechanical systems applications

    SciTech Connect (OSTI)

    Mouro, J.; Gualdino, A.; Chu, V. [Instituto de Engenharia de Sistemas e Computadores – Microsistemas e Nanotecnologias (INESC-MN) and IN – Institute of Nanoscience and Nanotechnology, 1000-029 Lisbon (Portugal); Conde, J. P. [Instituto de Engenharia de Sistemas e Computadores – Microsistemas e Nanotecnologias (INESC-MN) and IN – Institute of Nanoscience and Nanotechnology, 1000-029 Lisbon (Portugal); Department of Bioengineering, Instituto Superior Técnico (IST), 1049-001 Lisbon (Portugal)

    2013-11-14T23:59:59.000Z

    Thin-film silicon allows the fabrication of MEMS devices at low processing temperatures, compatible with monolithic integration in advanced electronic circuits, on large-area, low-cost, and flexible substrates. The most relevant thin-film properties for applications as MEMS structural layers are the deposition rate, electrical conductivity, and mechanical stress. In this work, n{sup +}-type doped hydrogenated amorphous and nanocrystalline silicon thin-films were deposited by RF-PECVD, and the influence of the hydrogen dilution in the reactive mixture, the RF-power coupled to the plasma, the substrate temperature, and the deposition pressure on the structural, electrical, and mechanical properties of the films was studied. Three different types of silicon films were identified, corresponding to three internal structures: (i) porous amorphous silicon, deposited at high rates and presenting tensile mechanical stress and low electrical conductivity, (ii) dense amorphous silicon, deposited at intermediate rates and presenting compressive mechanical stress and higher values of electrical conductivity, and (iii) nanocrystalline silicon, deposited at very low rates and presenting the highest compressive mechanical stress and electrical conductivity. These results show the combinations of electromechanical material properties available in silicon thin-films and thus allow the optimized selection of a thin silicon film for a given MEMS application. Four representative silicon thin-films were chosen to be used as structural material of electrostatically actuated MEMS microresonators fabricated by surface micromachining. The effect of the mechanical stress of the structural layer was observed to have a great impact on the device resonance frequency, quality factor, and actuation force.

  18. Identifying Electronic Properties Relevant to Improving the Performance and Stability of Amorphous Silicon Based Photovoltaic Cells: Final Subcontract Report, 27 November 2002--31 March 2005

    SciTech Connect (OSTI)

    Cohen, J. D.

    2005-11-01T23:59:59.000Z

    A major effort during this subcontract period has been to evaluate the microcrystalline Si material under development at United Solar Ovonics Corporation (USOC). This material is actually a hydrogenated nanocrystalline form of Si and it will be denoted in this report as nc-Si:H. Second, we continued our studies of the BP Solar high-growth samples. Third, we evaluated amorphous silicon-germanium alloys produced by the hot-wire chemical vapor deposition growth process. This method holds some potential for higher deposition rate Ge alloy materials with good electronic properties. In addition to these three major focus areas, we examined a couple of amorphous germanium (a-Ge:H) samples produced by the ECR method at Iowa State University. Our studies of the electron cyclotron resonance a-Ge:H indicated that the Iowa State a Ge:H material had quite superior electronic properties, both in terms of the drive-level capacitance profiling deduced defect densities, and the transient photocapacitance deduced Urbach energies. Also, we characterized several United Solar a Si:H samples deposited very close to the microcrystalline phase transition. These samples exhibited good electronic properties, with midgap defect densities slightly less than 1 x 1016 cm-3 in the fully light-degraded state.

  19. Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications

    SciTech Connect (OSTI)

    Theodorakos, I.; Zergioti, I.; Tsoukalas, D.; Raptis, Y. S., E-mail: yraptis@central.ntua.gr [Physics Department, National Technical University of Athens, Heroon Polytechniou 9, 15780 Zographou, Athens (Greece); Vamvakas, V. [Heliosphera SA, Industrial Area of Tripolis, 8th Building Block, 5th Road, GR-221 00 Tripolis (Greece)

    2014-01-28T23:59:59.000Z

    In this work, a picosecond diode pumped solid state laser and a nanosecond Nd:YAG laser have been used for the annealing and the partial nano-crystallization of an amorphous silicon layer. These experiments were conducted as an alternative/complementary to plasma-enhanced chemical vapor deposition method for fabrication of micromorph tandem solar cell. The laser experimental work was combined with simulations of the annealing process, in terms of temperature distribution evolution, in order to predetermine the optimum annealing conditions. The annealed material was studied, as a function of several annealing parameters (wavelength, pulse duration, fluence), as far as it concerns its structural properties, by X-ray diffraction, SEM, and micro-Raman techniques.

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

    SciTech Connect (OSTI)

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

    2014-08-04T23:59:59.000Z

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

  1. Manipulating hybrid structures of polymer/a-Si for thin film solar cells

    SciTech Connect (OSTI)

    Peng, Ying; He, Zhiqun, E-mail: zhqhe@bjtu.edu.cn, E-mail: J.I.B.Wilson@hw.ac.uk; Zhang, Zhi; Liang, Chunjun [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Diyaf, Adel; Ivaturi, Aruna; Wilson, John I. B., E-mail: zhqhe@bjtu.edu.cn, E-mail: J.I.B.Wilson@hw.ac.uk [SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2014-03-10T23:59:59.000Z

    A series of uniform polymer/amorphous silicon hybrid structures have been fabricated by means of solution-casting for polymer and radio frequency excited plasma enhanced chemical vapour deposition for amorphous silicon (a-Si:H). Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) functioned as a photoactive donor, while the silicon layer acted as an acceptor. It is found that matching the hole mobility of the polymer to the electron mobility of amorphous silicon is critical to improve the photovoltaic performance from hybrid cells. A three-layer p-i-n structure of ITO/PEDOT:PSS(200?nm)/i-Si(450?nm)/n-Si(200?nm)/Al with a power conversion efficiency of 4.78% under a standard test condition was achieved.

  2. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual technical report, April 1, 1995--March 31, 1996

    SciTech Connect (OSTI)

    Gordon, R.G.; Sato, H.; Liang, H.; Liu, X.; Thornton, J. [Harvard Univ., Cambridge, MA (United States)

    1996-08-01T23:59:59.000Z

    The general objective is to develop methods to deposit materials which can be used to make more efficient solar cells. The work is organized into three general tasks: Task 1. Develop improved methods for depositing and using transparent conductors of fluorine-doped zinc oxide in amorphous silicon solar cells Task 2. Deposit and evaluate titanium oxide as a reflection-enhancing diffusion barrier between amorphous silicon and an aluminum or silver back-reflector. Task 3. Deposit and evaluate electrically conductive titanium oxide as a transparent conducting layer on which more efficient and more stable superstrate cells can be deposited. About one-third of the current project resources are allocated to each of these three objectives.

  3. Increased Stabilized Performance Of Amorphous Silicon Based Devices Produced By Highly Hydrogen Diluted Lower Temperature Plasma Deposition.

    DOE Patents [OSTI]

    Li, Yaun-Min (Langhorne, PA); Bennett, Murray S. (Langhorne, PA); Yang, Liyou (Plainsboro, NJ)

    1997-07-08T23:59:59.000Z

    High quality, stable photovoltaic and electronic amorphous silicon devices which effectively resist light-induced degradation and current-induced degradation, are produced by a special plasma deposition process. Powerful, efficient single and multi-junction solar cells with high open circuit voltages and fill factors and with wider bandgaps, can be economically fabricated by the special plasma deposition process. The preferred process includes relatively low temperature, high pressure, glow discharge of silane in the presence of a high concentration of hydrogen gas.

  4. Increasing Stabilized Performance Of Amorphous Silicon Based Devices Produced By Highly Hydrogen Diluted Lower Temperature Plasma Deposition.

    DOE Patents [OSTI]

    Li, Yaun-Min (Langhorne, PA); Bennett, Murray S. (Langhorne, PA); Yang, Liyou (Plainsboro, NJ)

    1999-08-24T23:59:59.000Z

    High quality, stable photovoltaic and electronic amorphous silicon devices which effectively resist light-induced degradation and current-induced degradation, are produced by a special plasma deposition process. Powerful, efficient single and multi-junction solar cells with high open circuit voltages and fill factors and with wider bandgaps, can be economically fabricated by the special plasma deposition process. The preferred process includes relatively low temperature, high pressure, glow discharge of silane in the presence of a high concentration of hydrogen gas.

  5. Structural characterization of strained silicon grown on a SiGe buffer layer This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Florida, University of

    Structural characterization of strained silicon grown on a SiGe buffer layer This article has been silicon grown on a SiGe buffer layer J H Jang1, M S Phen1, A Gerger1, K S Jones1, J L Hansen2, A N Larsen2 of about 50 nm thick strained-Si/Si0.7Ge0.3/graded-SiGe/Si-substrate layers grown by MBE (molecular beam

  6. Real-time process sensing and metrology in amorphous and selective area silicon plasma enhanced chemical vapor deposition using in situ

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Real-time process sensing and metrology in amorphous and selective area silicon plasma enhanced Materials Processing, North Carolina State University, Raleigh, North Carolina 27695 Received 11 July 1996 silicon deposition. The ability of mass spectrometry to observe process faults in real time is also

  7. Optimization of transparent and reflecting electrodes for amorphous-silicon solar cells. Final subcontract report, 1 May 1991--30 April 1994

    SciTech Connect (OSTI)

    Gordon, R.G.; Hu, J.; Lacks, D.; Musher, J.; Thornton, J.; Liang, H. [Harvard Univ., Cambridge, MA (United States)

    1994-07-01T23:59:59.000Z

    Fluorine-doped zinc oxide was shown to have the lowest absorption loss of any of the known transparent conductors. An apparatus was constructed to deposit textured, transparent, conductive, fluorine-doped zinc oxide layers with uniform thickness over a 10 cm by 10 cm area, using inexpensive, high-productivity atmospheric pressure chemical vapor deposition. Amorphous silicon solar cells grown on these textured films show very high peak quantum efficiencies (over 90%). However, a significant contact resistance develops at the interface between the amorphous silicon and the zinc oxide. Transparent, conductive gallium-doped zinc oxide films were grown by APCVD at a low enough temperature (260{degree}C) to be deposited on amorphous silicon as a final conductive back contact to solar cells. A quantum-mechanical theory of bonding was developed and applied to some metal oxides; it forms a basis for understanding TCO structures and the stability of their interfaces with silicon.

  8. amorphous-nanocrystalline silicon thin: Topics by E-print Network

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

    THE POROUS SILICON PROCESS APPLYING CONVECTION for the first time to monocrystalline Si thin-film solar cells from the porous silicon (PSI) layer transfer for manufacturing high...

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

    E-Print Network [OSTI]

    Kang, Jin Sung

    2012-01-01T23:59:59.000Z

    Hahn, H. T. , "Photovoltaic Performance of Amorphous SiliconHahn, H. T. , "Photovoltaic Performance of Amorphous SiliconYS, Hahn HT. Photovoltaic Performance of Amorphous Silicon

  10. amorphous insulating thin: Topics by E-print Network

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

    Chuang3 , Barry G Kanicki, Jerzy 38 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  11. amorphization sputter rate: Topics by E-print Network

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

    Nakamura, Hiroaki 2012-01-01 154 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  12. amorphous biophotonic nanostructure: Topics by E-print Network

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

    nanostructure Anitescu, Mihai 169 Integration of amorphous and polycrystalline silicon thin-film transistors through selective crystallization of amorphous silicon Engineering...

  13. New Approaches for Passivation of Crystalline and Amorphous Silicon: Cooperative Research and Development Final Report, CRADA Number CRD-09-351

    SciTech Connect (OSTI)

    Sopori, B.

    2012-09-01T23:59:59.000Z

    New approaches of passivating crystalline, multicrystalline, and amorphous silicon will be explored. These will include the use of aqueous solution of KCN and a proprietary composition formulated by Mallinckrodt Baker, Inc. The surface passivation will be compared with that provided by an iodine-ethanol solution, and bulk passivation will be compared with that of H-passivation obtained by silicon nitride, in a fire-through process.

  14. Lithium implantation at low temperature in silicon for sharp buried amorphous layer formation and defect engineering

    SciTech Connect (OSTI)

    Oliviero, E. [CSNSM, CNRS-IN2P3-Universite Paris-Sud, Batiment 108, 91405 Orsay (France); David, M. L.; Beaufort, M. F.; Barbot, J. F. [Institut Pprime, CNRS-Universite de Poitiers-ENSMA, SP2MI, Bd Marie et Pierre Curie, BP30179, 86962 Futuroscope-Chasseneuil Cedex (France); Fichtner, P. F. P. [Departamento de Metalurgia, Universidade Federal do Rio Grande do Sul, Av Bento Goncalves 9500, Caixa Postal 15051, 90035-190 Porto Alegre, RS (Brazil)

    2013-02-28T23:59:59.000Z

    The crystalline-to-amorphous transformation induced by lithium ion implantation at low temperature has been investigated. The resulting damage structure and its thermal evolution have been studied by a combination of Rutherford backscattering spectroscopy channelling (RBS/C) and cross sectional transmission electron microscopy (XTEM). Lithium low-fluence implantation at liquid nitrogen temperature is shown to produce a three layers structure: an amorphous layer surrounded by two highly damaged layers. A thermal treatment at 400 Degree-Sign C leads to the formation of a sharp amorphous/crystalline interfacial transition and defect annihilation of the front heavily damaged layer. After 600 Degree-Sign C annealing, complete recrystallization takes place and no extended defects are left. Anomalous recrystallization rate is observed with different motion velocities of the a/c interfaces and is ascribed to lithium acting as a surfactant. Moreover, the sharp buried amorphous layer is shown to be an efficient sink for interstitials impeding interstitial supersaturation and {l_brace}311{r_brace} defect formation in case of subsequent neon implantation. This study shows that lithium implantation at liquid nitrogen temperature can be suitable to form a sharp buried amorphous layer with a well-defined crystalline front layer, thus having potential applications for defects engineering in the improvement of post-implantation layers quality and for shallow junction formation.

  15. 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.

  16. amorphous silicon-based solar: Topics by E-print Network

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

    networking issues away from the programmer via ... Beal, Jacob 58 A Silicon-Based Micro Gas Turbine Engine for Power Generation CERN Preprints Summary: This paper reports on our...

  17. Amorphous silicon solar cells. Quarterly report No. 1, 1 October 1980-31 December 1980

    SciTech Connect (OSTI)

    Carlson, D.E.; Balberg, I.; Crandall, R.S.; Dresner, J.; Goldstein, B.; Hanak, J.J.; Schade, H.E.; Staebler, D.L.; Weakliem, H.A.

    1981-02-01T23:59:59.000Z

    Progress is reported on the following: theoretical modeling, deposition and doping studies, experimental methods for the characterization of a-Si:H, formation of solar-cell structures, theoretical and experimental evaluation of solar-cell parameters, and stability studies. (MHR)

  18. Deposition of device quality, low hydrogen content, hydrogenated amorphous silicon at high deposition rates

    DOE Patents [OSTI]

    Mahan, Archie Harvin (Golden, CO); Molenbroek, Edith C. (Rotterdam, NL); Gallagher, Alan C. (Louisville, CO); Nelson, Brent P. (Golden, CO); Iwaniczko, Eugene (Lafayette, CO); Xu, Yueqin (Golden, CO)

    2002-01-01T23:59:59.000Z

    A method of fabricating device quality, thin-film a-Si:H for use as semiconductor material in photovoltaic and other devices, comprising in any order; positioning a substrate in a vacuum chamber adjacent a plurality of heatable filaments with a spacing distance L between the substrate and the filaments; heating the filaments to a temperature that is high enough to obtain complete decomposition of silicohydride molecules that impinge said filaments into Si and H atomic species; providing a flow of silicohydride gas, or a mixture of silicohydride gas containing Si and H, in said vacuum chamber while maintaining a pressure P of said gas in said chamber, which, in combination with said spacing distance L, provides a P.times.L product in a range of 10-300 mT-cm to ensure that most of the Si atomic species react with silicohydride molecules in the gas before reaching the substrate, to thereby grow a a-Si:H film at a rate of at least 50 .ANG./sec.; and maintaining the substrate at a temperature that balances out-diffusion of H from the growing a-Si:H film with time needed for radical species containing Si and H to migrate to preferred bonding sites.

  19. Deformation of amorphous silicon nanostructures subjected to monotonic and cyclic loading

    E-Print Network [OSTI]

    Wang, Gwo-Ching

    , advanced sensors, biomedical instruments, etc. has not only led to concerns about their long that of larger silicon speci- mens. Two classes of mechanisms have been proposed to explain this observation of the plastic behavior with the speci- men size.13,14 It has been observed that plastic deforma- tion

  20. Energetics of hydrogen in amorphous silicon: An ab initio study Blair Tuttle*

    E-Print Network [OSTI]

    Adams, James B

    and diffusion are well under- stood. The details of hydrogen transport and bonding in amor- phous silicon have bonding and diffusion.7 The quantity Ea in Fig. 1 is the activation energy for long-range diffusion, Em to H diffusion in c-Si with the bond center site being the transport level.8,11 Regarding the shallow

  1. The freezing tendency towards 4-coordinated amorphous network causes increase in heat capacity of supercooled Stillinger-Weber silicon

    E-Print Network [OSTI]

    Pankaj A. Apte; Nandlal Pingua; Arvind Kumar Gautam; Uday Kumar; Soohaeng Yoo Willow; Xiao Cheng Zeng; B. D. Kulkarni

    2014-04-10T23:59:59.000Z

    The supercooled liquid silicon, modeled by Stillinger-Weber potential, shows anomalous increase in heat capacity $C_p$, with a maximum $C_p$ value close to 1060 K at zero pressure. We study equilibration and relaxation of the supercooled SW Si, in the temperature range of 1060 K--1070 K at zero pressure. We find that as the relaxation of the metastable supercooled liquid phase initiates, a straight line region (SLR) is formed in cumulative potential energy distributions. The configurational temperature corresponding to the SLR is close to 1060 K, which was earlier identified as the freezing temperature of 4-coordinated amorphous network. The SLR is found to be tangential to the distribution of the metastable liquid phase and thus influences the broadness of the distribution. As the bath temperature is reduced from 1070 K to 1060 K, the effective temperature approaches the bath temperature which results in broadening of the metastable phase distribution. This, in turn, causes an increase in overall fluctuations of potential energy and hence an increase of heat capacity. We also find that during initial stages of relaxation, 4-coordinated atoms form 6-membered rings with a chair--like structure and other structural units that indicate crystallization. Simultaneously a strong correlation is established between the number of chair-shaped 6-membered rings and the number of 4-coordinated atoms in the system. This shows that all properties related to 4-coordinated particles are highly correlated as the SLR is formed in potential energy distributions and this can be interpreted as a consequence of `freezing' of amorphous network formed by 4-coordinated particles.

  2. Transport, Interfaces, and Modeling in Amorphous Silicon Based Solar Cells: Final Technical Report, 11 February 2002 - 30 September 2006

    SciTech Connect (OSTI)

    Schiff, E. A.

    2008-10-01T23:59:59.000Z

    Results for a-Si characteristics/modeling; photocarrier drift mobilities in a-Si;H, ..mu..c-Si:H, CIGS; hole-conducting polymers as p-layer for a-Si and c-Si; IR spectra of p/i and n/i interfaces in a-Si.

  3. ENHANCED GROWTH RATE AND SILANE UTILIZATION IN AMORPHOUS SILICON AND NANOCRYSTALLINE-SILICON SOLAR CELL DEPOSITION VIA GAS PHASE ADDITIVES

    SciTech Connect (OSTI)

    Ridgeway, R.G.; Hegedus, S.S.; Podraza, N.J.

    2012-08-31T23:59:59.000Z

    Air Products set out to investigate the impact of additives on the deposition rate of both ���µCSi and ���±Si-H films. One criterion for additives was that they could be used in conventional PECVD processing, which would require sufficient vapor pressure to deliver material to the process chamber at the required flow rates. The flow rate required would depend on the size of the substrate onto which silicon films were being deposited, potentially ranging from 200 mm diameter wafers to the 5.7 m2 glass substrates used in GEN 8.5 flat-panel display tools. In choosing higher-order silanes, both disilane and trisilane had sufficient vapor pressure to withdraw gas at the required flow rates of up to 120 sccm. This report presents results obtained from testing at Air Products�¢���� electronic technology laboratories, located in Allentown, PA, which focused on developing processes on a commercial IC reactor using silane and mixtures of silane plus additives. These processes were deployed to compare deposition rates and film properties with and without additives, with a goal of maximizing the deposition rate while maintaining or improving film properties.

  4. Amorphous silicon as electron transport layer for colloidal semiconductor nanocrystals light emitting diode

    SciTech Connect (OSTI)

    Song Tao; Shen Xiaojuan; Sun Baoquan [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Functional Nano and Soft Materials Laboratory (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123 (China); Zhang Fute [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Functional Nano and Soft Materials Laboratory (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123 (China); Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering, Soochow University, Suzhou 215123 (China); Zhang Xiaohong [Nano-Organic Photoelectronic Laboratory and Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Zhu Xiulin [Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering, Soochow University, Suzhou 215123 (China)

    2009-12-07T23:59:59.000Z

    We demonstrate the fabrication of light-emitting diodes (LEDs) made from all-inorganic colloidal semiconducting nanocrystals (NCs). The diode utilizes a sandwich structure formed by placing CdSe/CdS NCs between two layers of Si and Ag{sub x}O, which act as electron- and hole-transporting materials, respectively. The photoluminescence properties of NCs are rendered less dependent upon surface chemistry and chemical environment by growing a thick CdS shell. It also enhances stability of the NCs during the process of magnetron sputtering for silicon deposition. The resulting LED device exhibits a low turn-on voltage of 2.5 V and the maximum external quantum efficiency of nearly 0.08%.

  5. High-Efficiency Amorphous Silicon and Nanocrystalline Silicon-Based Solar Cells and Modules: Final Technical Progress Report, 30 January 2006 - 29 January 2008

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.

    2008-05-01T23:59:59.000Z

    United Solar Ovonic successfully used its spectrum-splitting a-Si:H/a-SiGe:H/a-SiGe:H triple-junction structure in their manufacturing plants, achieving a manufacturing capacity of 118 MW in 2007, and set up a very aggressive expansion plan to achieve grid parity.

  6. Comparative life-cycle energy payback analysis of multi-junction a-SiGe and nanocrystalline/a-Si modules

    SciTech Connect (OSTI)

    Fthenakis, V.; Kim, H.

    2010-07-15T23:59:59.000Z

    Despite the publicity of nanotechnologies in high tech industries including the photovoltaic sector, their life-cycle energy use and related environmental impacts are understood only to a limited degree as their production is mostly immature. We investigated the life-cycle energy implications of amorphous silicon (a-Si) PV designs using a nanocrystalline silicon (nc-Si) bottom layer in the context of a comparative, prospective life-cycle analysis framework. Three R and D options using nc-Si bottom layer were evaluated and compared to the current triple-junction a-Si design, i.e., a-Si/a-SiGe/a-SiGe. The life-cycle energy demand to deposit nc-Si was estimated from parametric analyses of film thickness, deposition rate, precursor gas usage, and power for generating gas plasma. We found that extended deposition time and increased gas usages associated to the relatively high thickness of nc-Si lead to a larger primary energy demand for the nc-Si bottom layer designs, than the current triple-junction a-Si. Assuming an 8% conversion efficiency, the energy payback time of those R and D designs will be 0.7-0.9 years, close to that of currently commercial triple-junction a-Si design, 0.8 years. Future scenario analyses show that if nc-Si film is deposited at a higher rate (i.e., 2-3 nm/s), and at the same time the conversion efficiency reaches 10%, the energy-payback time could drop by 30%.

  7. Research on stable, high-efficiency, large-area amorphous silicon based modules -- Task B

    SciTech Connect (OSTI)

    Mitchell, K.W.; Willet, D.R. (Siemens Solar Industries, Camarillo, CA (USA))

    1990-10-01T23:59:59.000Z

    This report documents progress in developing a stable, high- efficiency, four-terminal hybrid tandem module. The module consists of a semi-transparent, thin-film silicon:hydrogen alloy (TFS) top circuit and a copper indium diselenide (CuInSe{sub 2}) bottom circuit. Film deposition and patterning processes were successfully extended to 0.4-m{sup 2} substrates. A 33.2-W (8.4% efficient) module with a 3970-cm{sup 2} aperture area and a white back reflector was demonstrated; without the back reflector, the module produced 30.2 W (7.6% efficient). Placing a laminated, 31.6-W, 8.1%-efficient CuInSe{sub 2} module underneath this TFS module, with an air gap between the two, produces 11.2 W (2.9% efficient) over a 3883-cm{sup 2} aperture area. Therefore, the four-terminal tandem power output is 41.4 W, translating to a 10.5% aperture-area efficiency. Subsequently, a 37.8-W (9.7% aperture-area efficiency) CuInSe{sub 2} module was demonstrated with a 3905-cm{sup 2} aperture area. Future performances of single-junction and tandem modules of this size were modeled, and predicted power outputs exceed 50 W (13% efficient) for CuInSe{sub 2} and 65 W (17% efficient) for TFS/CuInSe{sub 2} tandem modules.

  8. 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.

  9. Deposition of device quality, low hydrogen content, hydrogenated amorphous silicon at high deposition rates with increased stability using the hot wire filament technique

    DOE Patents [OSTI]

    Molenbroek, Edith C. (Utrecht, NL); Mahan, Archie Harvin (Golden, CO); Gallagher, Alan C. (Louisville, CO)

    2000-09-26T23:59:59.000Z

    A method or producing hydrogenated amorphous silicon on a substrate, comprising the steps of: positioning the substrate in a deposition chamber at a distance of about 0.5 to 3.0 cm from a heatable filament in the deposition chamber; maintaining a pressure in said deposition chamber in the range of about 10 to 100 millitorr and pressure times substrate-filament spacing in the range of about 10 to 100 millitorr-cm, heating the filament to a temperature in the range of about 1,500 to 2,000.degree. C., and heating the substrate to a surface temperature in the range of about 280 to 475.degree. C.; and flowing silicohydride gas into the deposition chamber with said heated filament, decomposing said silicohydride gas into silicon and hydrogen atomic species and allowing products of gas reactions between said atomic species and the silicohydride gas to migrate to and deposit on said substrate while adjusting and maintaining said pressure times substrate-filament spacing in said deposition chamber at a value in said 10 to 100 millitorr range to produce statistically about 3 to 50 atomic collisions between the silicon and hydrogen atomic species migrating to said substrate and undecomposed molecules of the silane or other silicohydride gas in the deposition chamber.

  10. The formation of the positive, fixed charge at c-Si(111)/a-Si$_3$N$_{3.5}$:H interfaces

    E-Print Network [OSTI]

    Hintzsche, L E; Marsman, M; Lamers, M W P E; Weeber, A W; Kresse, G

    2015-01-01T23:59:59.000Z

    Modern electronic devices are unthinkable without the well-controlled formation of interfaces at heterostructures. These often involve at least one amorphous material. Modeling such interfaces poses a significant challenge, since a meaningful result can only be expected by using huge models or by drawing from many statistically independent samples. Here we report on the results of high throughput calculations for interfaces between crystalline silicon (c-Si) and amorphous silicon nitride (a-Si$_3$N$_{3.5}$:H), which are omnipresent in commercially available solar cells. The findings reconcile only partly understood key features. At the interface, threefold coordinated Si atoms are present. These are caused by the structural mismatch between the amorphous and crystalline part. The local Fermi level of undoped c-Si lies well below that of a-SiN:H. To align the Fermi levels in the device, charge is transferred from the a-SiN:H part to the c-Si part resulting in an abundance of positively charged, threefold coord...

  11. 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.

  12. Productivity Enhancement for Manufacturing of Amorphous Silicon PV Modules: Final Technical Progress Report; 1 July 2002--31 October 2004

    SciTech Connect (OSTI)

    Volltrauer, H.; Jansen, K.

    2005-02-01T23:59:59.000Z

    The overall objective of this subcontract over its two-year duration is to continue the advancement of Energy Photovoltaics, Inc.'s (EPV) a-Si production manufacturing technology and improve the production equipment used in manufacturing. This will allow EPV to reduce module costs by increasing module output, throughput, and yield. EPV conducted parallel research efforts for achieving higher stabilized module power output through improvements in several manufacturing processing steps, with particular emphasis on the thin-film deposition process. The dual goals of achieving a 20% gain in stabilized output and a 20% reduction in direct costs were accomplished. The 20% gain in stabilized output increased the power of the standard 0.79 m2 module to about 45 watts. This was achieved through optimizing the a-Si deposition process to improve stability, increasing the active area of the module, and developing a ZnO/Al back reflector to increase the light absorption of the a-Si. Additionally, improvements were made to the a-Si uniformity, and an improved TCO was incorporated into the standard product. The goal of reducing costs by 20% was exceeded, resulting in an estimated direct cost of $1.41/W, for the process in EPV's New Jersey facility. This was accomplished through a complete review of the process that resulted in lower material costs, lower labor costs, less downtime, and higher module power, as noted above. The process was streamlined and made more efficient by eliminating or combining process steps, and selected processes were automated. In addition, improvements were made to the characterization and measurement techniques used in the module optimization process.

  13. Amorphous thin films for solar-cell applications. Final report, September 11, 1978-September 10, 1979

    SciTech Connect (OSTI)

    Carlson, D E; Balberg, I; Crandall, R S; Goldstein, B C; Hanak, J J; Pankove, J I; Staebler, D L; Weakliem, H A; Williams, R

    1980-02-01T23:59:59.000Z

    In Section II, Theoretical Modeling, theories for the capture of electrons by deep centers in hydrogenated amorphous silicon (a-Si:H) and for field-dependent quantum efficiency in a-Si:H are presented. In Section III, Deposition and Doping Studies, the optimization of phosphorus-doped a-Si:H carried out in four different discharge systems is described. Some details of the dc proximity and rf magnetron discharge systems are also provided. Preliminary mass spectroscopy studies of the rf magnetron discharge in both SiH/sub 4/ and SiF/sub 4/ are presented. In Section IV, Experimental Methods for Characterizing a-Si:H, recent work involving photoluminescence of fluorine-doped a-Si:H, photoconductivity spectra, the photoelectromagnetic effect, the photo-Hall effect and tunneling into a-Si:H is presented. Also, studies of the growth mechanism of Pt adsorbed on both crystalline Si and a-Si:H are described. Measurements of the surface photovoltage have been used to estimate the distribution of surface states of phosphorus-doped and undoped a-Si:H. Section V, Formation of Solar-Cell Structures, contains information on stacked or multiple-junction a-Si:H solar cells. In Section VI, Theoretical and Experimental Evaluation of Solar-Cell Parameters, an upper limit of approx. = 400 A is established for the hole diffusion length in undoped a-Si:H. A detailed description of carrier generation, recombination and transport in a-Si:H solar cells is given. Finally, some characteristics of Pd-Schottky-barrier cells are described for different processing histories.

  14. Hole drift mobility measurements in amorphous silicon-carbon alloys Qing Gu, Qi Wang, and Eric A. Schiff

    E-Print Network [OSTI]

    Schiff, Eric A.

    in the elec- tronic properties and photovoltaic performance of amor- phous silicon alloys with widened band.`t As for a a-Sil-,Ge,:H, there is relatively little degradation as the band gap is modified. At the end). Additional information on photovoltaic properties and deposition procedures for similar materials are given

  15. Near single-crystalline, high-carrier-mobility silicon thin film on a polycrystalline/amorphous substrate

    DOE Patents [OSTI]

    Findikoglu, Alp T. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM); Matias, Vladimir (Santa Fe, NM); Choi, Woong (Los Alamos, NM)

    2009-10-27T23:59:59.000Z

    A template article including a base substrate including: (i) a base material selected from the group consisting of polycrystalline substrates and amorphous substrates, and (ii) at least one layer of a differing material upon the surface of the base material; and, a buffer material layer upon the base substrate, the buffer material layer characterized by: (a) low chemical reactivity with the base substrate, (b) stability at temperatures up to at least about 800.degree. C. under low vacuum conditions, and (c) a lattice crystal structure adapted for subsequent deposition of a semiconductor material; is provided, together with a semiconductor article including a base substrate including: (i) a base material selected from the group consisting of polycrystalline substrates and amorphous substrates, and (ii) at least one layer of a differing material upon the surface of the base material; and, a buffer material layer upon the base substrate, the buffer material layer characterized by: (a) low chemical reactivity with the base substrate, (b) stability at temperatures up to at least about 800.degree. C. under low vacuum conditions, and (c) a lattice crystal structure adapted for subsequent deposition of a semiconductor material, and, a top-layer of semiconductor material upon the buffer material layer.

  16. Research on the structural and electronic properties of defects in amorphous silicon. Final subcontract report, September 1989--December 1990

    SciTech Connect (OSTI)

    Street, R.A. [Xerox Palo Alto Research Center, CA (United States)

    1991-12-01T23:59:59.000Z

    The work performed for this contract focused on the saturation of light-induced effects, hydrogen-mediated metastability and growth, defects and electronic properties, and remote hydrogen plasma growth. This work included research on hydrogen chemical reactions, hydrogen density-of-states model and metastability, hydrogen bonding configurations, a model for the role of hydrogen complexes in the metastability, and hydrogen chemical potential and growth structure. This document also covers research on thermal generation currents in p-i-n diodes, field dependence of the generation current, metastability effects at contacts, and potential fluctuations in compensated a-Si:H. Information is included on plasma diagnostics using electron spin resonance and nuclear magnetic resonance measurements of remote hydrogen plasma films.

  17. Studies on relative effects of charged and neutral defects in hydrogenated amorphous silicon. Final report, 1 October 1989--31 December 1990

    SciTech Connect (OSTI)

    Silver, M. [North Carolina Univ., Chapel Hill, NC (United States)

    1992-02-01T23:59:59.000Z

    This report covers the third year of a continuing research study to understand the relative importance of charged and neutral defects in amorphous silicon. The objective of the study is to explore the electronic structure, including neutral and charged defects, an optoelectronic effects including the formation of Staebler-Wronski defects. The study concentrated on exploring electroluminescence experimentally and interpreting the results employing a simple guiding model. The simple guiding model assumes an exponential density of states and recombination rate constants (radiative and non-radiative) which are governed by hopping transitions. Measurements were also made as a function of photodegradation of the material. The results implicate that the radiative recombination processes are not distant pair tunneling but rather results from electrons hopping down due to the coulomb interactions. Preliminary experiments have been made on the effect of photodegradation on transient space charge limited currents in n/i/n structures. These experiments can directly yield information on the occupied defects centers induced by the photodegradation and are not a result of recombination processes. To date the results seems to be consistent with a picture which places the doubly occupied defects at quite a high energy ({approx_equal} 0.4 e.v. below the conduction band).

  18. High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells: Final Technical Report, 1 September 2001--6 March 2005

    SciTech Connect (OSTI)

    Deng, X.

    2006-01-01T23:59:59.000Z

    The objectives for the University of Toledo are to: (1) establish a transferable knowledge and technology base for fabricating high-efficiency triple-junction a-Si-based solar cells, and (2) develop high-rate deposition techniques for the growing a-Si-based and related alloys, including poly-Si, c-Si, a-SiGe, and a-Si films and photovoltaic devices with these materials.

  19. Equilibrium shapes of polycrystalline silicon nanodots

    SciTech Connect (OSTI)

    Korzec, M. D., E-mail: korzec@math.tu-berlin.de; Wagner, B., E-mail: bwagner@math.tu-berlin.de [Department of Mathematics, Technische Universität Berlin, Straße des 17. Juni 136, 10623 Berlin (Germany); Roczen, M., E-mail: maurizio.roczen@physik.hu-berlin.de [Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin (Germany); Schade, M., E-mail: martin.schade@physik.uni-halle.de [Zentrum für Innovationskompetenz SiLi-nano, Martin-Luther-Universität Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Straße 3, 06120 Halle (Germany); Rech, B., E-mail: bernd.rech@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Institute for Silicon Photovoltaics, Kekuléstraße 5, 12489 Berlin (Germany)

    2014-02-21T23:59:59.000Z

    This study is concerned with the topography of nanostructures consisting of arrays of polycrystalline nanodots. Guided by transmission electron microscopy (TEM) measurements of crystalline Si (c-Si) nanodots that evolved from a “dewetting” process of an amorphous Si (a-Si) layer from a SiO{sub 2} coated substrate, we investigate appropriate formulations for the surface energy density and transitions of energy density states at grain boundaries. We introduce a new numerical minimization formulation that allows to account for adhesion energy from an underlying substrate. We demonstrate our approach first for the free standing case, where the solutions can be compared to well-known Wulff constructions, before we treat the general case for interfacial energy settings that support “partial wetting” and grain boundaries for the polycrystalline case. We then use our method to predict the morphologies of silicon nanodots.

  20. amorphous hydrogenated carbon: Topics by E-print Network

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

    PLASMA DISCHARGE CiteSeer Summary: Abstract. Nickelhydrogenated amorphous carbon composite films have been deposited on silicon and stainless steel substrates by combining...

  1. Structure-property relations in amorphous carbon for photovoltaics

    SciTech Connect (OSTI)

    Risplendi, Francesca; Cicero, Giancarlo [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, 10129 Torino (Italy); Bernardi, Marco [Department of Physics, University of California, Berkeley, California 94720 (United States); Grossman, Jeffrey C., E-mail: jcg@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-07-28T23:59:59.000Z

    Carbon is emerging as a material with great potential for photovoltaics (PV). However, the amorphous form (a-C) has not been studied in detail as a PV material, even though it holds similarities with amorphous Silicon (a-Si) that is widely employed in efficient solar cells. In this work, we correlate the structure, bonding, stoichiometry, and hydrogen content of a-C with properties linked to PV performance such as the electronic structure and optical absorption. We employ first-principles molecular dynamics and density functional theory calculations to generate and analyze a set of a-C structures with a range of densities and hydrogen concentrations. We demonstrate that optical and electronic properties of interest in PV can be widely tuned by varying the density and hydrogen content. For example, sunlight absorption in a-C films can significantly exceed that of a same thickness of a-Si for a range of densities and H contents in a-C. Our results highlight promising features of a-C as the active layer material of thin-film solar cells.

  2. Amorphous-diamond electron emitter

    DOE Patents [OSTI]

    Falabella, Steven (Livermore, CA)

    2001-01-01T23:59:59.000Z

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  3. a-si solar cells: Topics by E-print Network

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

    for the development of amorphous Si solar cells Seung May 2010 Keywords: a-Si:H Thin film Si solar cell Spectroscopic ellipsometry (SE) a b s t r a c t We Park, Byungwoo...

  4. a-si solar cell: Topics by E-print Network

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

    for the development of amorphous Si solar cells Seung May 2010 Keywords: a-Si:H Thin film Si solar cell Spectroscopic ellipsometry (SE) a b s t r a c t We Park, Byungwoo...

  5. 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.

  6. Local network structure of a-SiC:H and its correlation with dielectric function

    SciTech Connect (OSTI)

    Kageyama, Shota; Matsuki, Nobuyuki; Fujiwara, Hiroyuki [Center of Innovative Photovoltaic Systems (CIPS), Gifu University, 1-1 Yanagido, Gifu 501-1193 (Japan)] [Center of Innovative Photovoltaic Systems (CIPS), Gifu University, 1-1 Yanagido, Gifu 501-1193 (Japan)

    2013-12-21T23:59:59.000Z

    The microscopic disordered structures of hydrogenated amorphous silicon carbide (a-Si{sub 1?x}C{sub x}:H) layers with different carbon contents have been determined based on the correlations between the dielectric function in the ultraviolet/visible region and the local bonding states studied by high-sensitivity infrared attenuated total reflection spectroscopy. We find that the microscopic structure of the a-Si{sub 1?x}C{sub x}:H layers fabricated by plasma-enhanced chemical vapor deposition shows a sharp structural transition at a boundary of x = 6.3 at. %. In the regime of x ? 6.3 at. %, (i) the amplitude of the a-SiC:H dielectric function reduces and (ii) the SiH{sub 2} content increases drastically with x, even though most of the C atoms are introduced into the tetrahedral sites without bonding with H. In the regime of x > 6.3 at. %, on the other hand, (i) the amplitude of the dielectric function reduces further and (ii) the concentration of the sp{sup 3} CH{sub n} (n = 2,3) groups increases. Moreover, we obtained the direct evidence that the sp{sup 2} C bonding state in the a-SiC matrix exists in the configuration of C = CH{sub 2} and the generation of the graphite-like C = CH{sub 2} unit suppresses the band gap widening significantly. At high C contents of x > 6.3 at. %, the a-SiC:H layers show quite porous structures due to the formation of microvoids terminated with the SiH{sub 2}/CH{sub n} groups. By taking the SiH{sub 2}/CH{sub n} microvoid generation in the network and the high-energy shift of the dielectric function by the local bonding states into account, the a-SiC:H dielectric function model has been established. From the analysis using this model, we have confirmed that the a-SiC:H optical properties in the ultraviolet/visible region are determined almost completely by the local network structures.

  7. Research on defects and transport in amorphous-silicon-based semiconductors. Annual subcontract report, 20 February 1992--19 February 1993

    SciTech Connect (OSTI)

    Schiff, E.A.; Gu, Q.; Wang, Q. [Syracuse Univ., NY (US)

    1993-08-01T23:59:59.000Z

    This report describes Phase 2 progress in two areas: (1) electron drift and conduction band tails in a-Si{sub 1{minus}x}Ge{sub x}:H and a-Si{sub 1{minus}x}C{sub x}:H alloys, and (2) optical bias effects on electron trapping and emission in a-Si:H. The authors completed a comprehensive study of electron drift in a-Si{sub 1{minus}x}Ge{sub x}:H alloys, including correlations of the drift parameters with {open_quotes}blue{close_quotes} fill factor measurements and open-circuit voltages in solar cells. They began a study of electron and hole drift in a-Si{sub 1{minus}x}C{sub x}:H, but, at present, they have only confirmed that C alloying degrades the electron drift mobility in a-Si{sub 1{minus}x}C{sub x}:H. They completed a study of optical bias effects on transient photocharge measurements in a-Si:H, which clarified that optical bias effects found in earlier photocurrent transient measurements occur because deep trapping is suppressed by optical bias.

  8. Thermal decomposition of silane to form hydrogenated amorphous Si film

    DOE Patents [OSTI]

    Strongin, Myron (Center Moriches, NY); Ghosh, Arup K. (Rocky Point, NY); Wiesmann, Harold J. (Wantagh, NY); Rock, Edward B. (Oxford, GB); Lutz, III, Harry A. (Midlothian, VA)

    1980-01-01T23:59:59.000Z

    This invention relates to hydrogenated amorphous silicon produced by thermally decomposing silano (SiH.sub.4) or other gases comprising H and Si, at elevated temperatures of about 1700.degree.-2300.degree. C., and preferably in a vacuum of about 10.sup.-8 to 10.sup.-4 torr, to form a gaseous mixture of atomic hydrogen and atomic silicon, and depositing said gaseous mixture onto a substrate outside said source of thermal decomposition to form hydrogenated amorphous silicon.

  9. alkali-resistant silicon nitride: Topics by E-print Network

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

    Amorphous Silicon B. L. Zink,1,2,* R. Pietri,1. Above 50 K the thermal conductivity of thin-film amorphous silicon agrees with values previously Hellman, Frances 131 Profiles:...

  10. Two-stage Model for Lifetime Prediction of Highly Stable Amorphous-Silicon Thin-Film Transistors under Low-Gate Field

    E-Print Network [OSTI]

    that (i) a "unified stretched exponential fit" models the drain current degradation from 60°C to 140 stable back-channel passivated (BCP) a-Si TFTs were fabricated with a standard bottom-gate non field of 2.0×105 V/cm) and a constant drain voltage of 7.5V. The positive threshold voltage shift of a

  11. Research on defects and transport in amorphous silicon-based semiconductors. Annual subcontract report, 20 February 1991--19 February 1992

    SciTech Connect (OSTI)

    Schiff, E.A.; Antoniadis, H.; Lee, J.K.; Wang, Q. [Syracuse Univ., NY (United States)

    1992-04-01T23:59:59.000Z

    This report describes the results from research on two topics: (1) the effects of light-soaking on the electron drift mobility in a-Si:H, and (2) modulated electron spin resonance measurements and their relationship to the electronic correlation energy of the D center in a-Si:H. Both of these projects were undertaken to better determine where the ``standard`` model for a-Si:H breaks down. The standard model is reasonably successful in accounting for the most elementary ``deep trapping`` aspects of electron and hole transport in a-Si:H, and it accounts adequately for the sub-band-gap optical properties. However, it is much less clear whether it provides a sufficient basis for understanding several effects which are crucial in operating solar cells: electron and hole mobilities and recombination in the presence of light-bias and space-charge. In the standard model, one would not expect significant effects on drift mobilities due to light-soaking, which would be envisioned as simply increasing the D-center density. Similarly, in the standard model one would not anticipate a significant temperature dependence to electron spin resonance, because essentially all spins are already detected. Discussions in the available literature on the evidence regarding both effects were inconclusive. The work reported here sets considerably more stringent constraints on the magnitude of the two effects.

  12. Electronic Origin For The Phase Transition From Amorphous LixSi...

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

    Li15Si4 . Abstract: Silicon has been widely explored as an anode material for lithium ion battery. Upon lithiation, silicon transforms to amorphous LixSi (a-LixSi) via...

  13. Development of Thin Film Silicon Solar Cell Using Inkjet Printed Silicon and Other Inkjet Processes: Cooperative Research and Development Final Report, CRADA Number CRD-07-260

    SciTech Connect (OSTI)

    Sopori, B.

    2012-04-01T23:59:59.000Z

    The cost of silicon photovoltaics (Si-PV) can be greatly lowered by developing thin-film crystalline Si solar cells on glass or an equally lower cost substrate. Typically, Si film is deposited by thermal evaporation, plasma enhanced chemical vapor deposition, and sputtering. NREL and Silexos have worked under a CRADA to develop technology to make very low cost solar cells using liquid organic precursors. Typically, cyclopentasilane (CPS) is deposited on a glass substrate and then converted into an a-Si film by UV polymerization followed by low-temperature optical process that crystallizes the amorphous layer. This technique promises to be a very low cost approach for making a Si film.

  14. amorphous thin films: Topics by E-print Network

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

    Amorphous Silicon Thin-Film Transistor Pixel.S.A. 1 LG Philips LCD Research and Development Center, An-Yang, 431-080, Korea (Received July 23, 2006; accepted October 31, 2006;...

  15. amorphous thin film: Topics by E-print Network

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

    Amorphous Silicon Thin-Film Transistor Pixel.S.A. 1 LG Philips LCD Research and Development Center, An-Yang, 431-080, Korea (Received July 23, 2006; accepted October 31, 2006;...

  16. 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 ...

  17. More stable hybrid organic solar cells deposited on amorphous Si electron transfer layer

    SciTech Connect (OSTI)

    Samiee, Mehran; Modtland, Brian; Dalal, Vikram L., E-mail: vdalal@iastate.edu [Iowa State University, Dept. of Electrical and Computer Engineering, Ames, Iowa 50011 (United States); Aidarkhanov, Damir [Nazarbayev University, Astana (Kazakhstan)

    2014-05-26T23:59:59.000Z

    We report on defect densities, performance, and stability of organic/inorganic hybrid solar cells produced using n-doped inorganic amorphous silicon-carbide layers as the electron transport layer (ETL). The organic material was poly-3-hexyl-thiophene (P3HT) and heterojunction was formed using phenyl-C{sub 71}-Butyric-Acid-Methyl Ester (PCBM). For comparison, inverted solar cells fabricated using Cs{sub 2}CO{sub 3} as ETL were fabricated. Defect densities and subgap quantum efficiency curves were found to be nearly identical for both types of cells. The cells were subjected to 2xsun illumination and it was found that the cells produced using doped a-Si as ETL were much more stable than the cells produced using Cs{sub 2}CO{sub 3}.

  18. amorphous carbon particles: Topics by E-print Network

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

    amorphous carbon particles First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Amorphous Silicon Based...

  19. advanced silicon space: Topics by E-print Network

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

    to the astronomical identifications 11 Advanced Multilayer Amorphous Silicon Thin-Film Transistor Structure: Film Thickness Effect on Its Electrical Performance and Contact...

  20. .beta.-silicon carbide protective coating and method for fabricating same

    DOE Patents [OSTI]

    Carey, Paul G. (Mountain View, CA); Thompson, Jesse B. (Brentwood, CA)

    1994-01-01T23:59:59.000Z

    A polycrystalline beta-silicon carbide film or coating and method for forming same on components, such as the top of solar cells, to act as an extremely hard protective surface, and as an anti-reflective coating. This is achieved by DC magnetron co-sputtering of amorphous silicon and carbon to form a SiC thin film onto a surface, such as a solar cell. The thin film is then irradiated by a pulsed energy source, such as an excimer laser, to synthesize the poly- or .mu.c-SiC film on the surface and produce .beta.--SiC. While the method of this invention has primary application in solar cell manufacturing, it has application wherever there is a requirement for an extremely hard surface.

  1. [beta]-silicon carbide protective coating and method for fabricating same

    DOE Patents [OSTI]

    Carey, P.G.; Thompson, J.B.

    1994-11-01T23:59:59.000Z

    A polycrystalline beta-silicon carbide film or coating and method for forming same on components, such as the top of solar cells, to act as an extremely hard protective surface, and as an anti-reflective coating are disclosed. This is achieved by DC magnetron co-sputtering of amorphous silicon and carbon to form a SiC thin film onto a surface, such as a solar cell. The thin film is then irradiated by a pulsed energy source, such as an excimer laser, to synthesize the poly- or [mu]c-SiC film on the surface and produce [beta]-SiC. While the method of this invention has primary application in solar cell manufacturing, it has application wherever there is a requirement for an extremely hard surface. 3 figs.

  2. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    SciTech Connect (OSTI)

    Cho, Gyuseong

    1992-03-01T23:59:59.000Z

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was {approximately}400 MHz and the noise charge {approximately}1000 electrons at a 1 {mu}sec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of {approximately}0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  3. 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.

  4. FILM ADHESION IN TRIPLE JUNCTION a-Si SOLAR CELLS ON POLYIMIDE and X. Deng1,2

    E-Print Network [OSTI]

    Deng, Xunming

    FILM ADHESION IN TRIPLE JUNCTION a-Si SOLAR CELLS ON POLYIMIDE SUBSTRATES A. Vijh1,2 , X. Yang1 , W encountered during fabrication of triple junction a-Si solar cells on polyimide substrates is the adhesion silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and Gouldflex

  5. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    electricity. The sun provides more energy in the form ofwith the sun without electric energy being extracted. µ e +of global energy demand directly from the sun[5], and much

  6. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    and Photovoltaic Performance . . . . . . . . . . . . . . .conduction and photovoltaic performance. Experimental dataElectronic and Photovoltaic Performance We also probed oxide

  7. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    way to do better. A photovoltaic cell, or solar cell, is aFor this thesis, I made photovoltaic cells using a Schottkyphotovoltaic processes oc- cur in a Schottky barrier solar cell. . . . . . . . . . . . . . . . . .

  8. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    of Photovoltaics . . . . . . . . . . . . . . . . 4.3.1Graphene 4 Photovoltaics 4.1 Motivation and Materialby the European Photovoltaics Industry Association for

  9. Amorphous Silicon-Carbon Nanostructure Photovoltaic Devices

    E-Print Network [OSTI]

    Schriver, Maria Christine

    2012-01-01T23:59:59.000Z

    domain size. . . . . . . . . 6.7 Short circuit current andthat flows, the short-circuit current. When j is zero, thecircuit voltage j SC Short circuit current FF Fill factor

  10. 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.

  11. 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.

  12. 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.

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

    SciTech Connect (OSTI)

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

    2006-10-03T23:59:59.000Z

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

  14. SILANE SAFETY IN AMORPHOUS SILICON AND SILICON NITRIDE OPERATIONS

    E-Print Network [OSTI]

    and solar cells. The U.S. EPA Risk Management Program's (RMP's) national database includes six accidents of these accidents resulted in deaths or severe damages, but two injuries and $686K in economic losses were reported Carlisle2 and Waikei Chan2 1 National Photovoltaic Environmental Health and Safety Research Center

  15. International Conference on Advanced Materials: Cancun 2001 Design Considerations for a Hybrid AmorphousDesign Considerations for a Hybrid Amorphous

    E-Print Network [OSTI]

    electrical/optical/electrochemical modeling ­ Triple junction amorphous silicon encapsulated photoelectrodes ­ Triple junction CIGS encapsulated photoelectrodes Hybrid Solid-State/Photoelectrochemical H2 Electrodes and system losses for water-splitting. Efficiency ·Solar to hydrogen efficiency: ·D.O.E. goal of 10% at AM 1

  16. Amorphization of crystalline Si due to heavy and light ion irradiation

    SciTech Connect (OSTI)

    Edmondson, P. D.; Riley, D. J.; Donnelly, S. E. [Institute for Materials Research, University of Salford, Manchester M5 4WT (United Kingdom); Birtcher, R. C. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2009-08-15T23:59:59.000Z

    The formation of amorphous silicon in crystalline silicon by bombardment with light (Si) and heavy (Xe) ions has been investigated by transmission electron microscopy with in situ ion irradiation. Experiments have been carried out at room temperature and low temperature (50 K) and the results are compared to a simple numerical model for amorphization. The results indicate that the amorphization mechanisms for both irradiations are heterogeneous in nature and that numerous overlaps of the collision cascade are generally required to render the crystal amorphous. Following from this, the nature of the material within the confines of collision cascades will be discussed and it will be shown that the individual cascade volume is not necessarily amorphous as previously described in the scientific literature but contains varying degrees of damage depending on the energy deposited within the cascade.

  17. Amorphization of crystalline Si due to heavy and light ion irradiation.

    SciTech Connect (OSTI)

    Edmondson, P. D.; Riley, D. J.; Birtcher, R. C.; Donnelly, S. E.; Materials Science Division; Univ. of Salford

    2009-08-01T23:59:59.000Z

    The formation of amorphous silicon in crystalline silicon by bombardment with light (Si) and heavy (Xe) ions has been investigated by transmission electron microscopy with in situ ion irradiation. Experiments have been carried out at room temperature and low temperature (50 K) and the results are compared to a simple numerical model for amorphization. The results indicate that the amorphization mechanisms for both irradiations are heterogeneous in nature and that numerous overlaps of the collision cascade are generally required to render the crystal amorphous. Following from this, the nature of the material within the confines of collision cascades will be discussed and it will be shown that the individual cascade volume is not necessarily amorphous as previously described in the scientific literature but contains varying degrees of damage depending on the energy deposited within the cascade.

  18. Aluminum recycling from reactor walls: A source of contamination in a-Si:H thin films

    SciTech Connect (OSTI)

    Longeaud, C.; Ray, P. P.; Bhaduri, A.; Daineka, D.; Johnson, E. V.; Roca i Cabarrocas, P. [Laboratoire de Genie Electrique de Paris (UMR 8507 CNRS), Supelec, Universites Paris VI and XI, 11 Rue Joliot-Curie, Plateau de Moulon, 91190 Gif sur Yvette (France); Laboratoire de Physique des Interfaces et des Couches Minces (UMR 7647 CNRS), Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2010-11-15T23:59:59.000Z

    In this article, the authors investigate the contamination of hydrogenated amorphous silicon thin films with aluminum recycled from the walls and electrodes of the deposition reactor. Thin films of hydrogenated amorphous silicon were prepared under various conditions by a standard radio frequency plasma enhanced chemical vapor deposition process in two reactors, the chambers of which were constructed of either aluminum or stainless steel. The authors have studied the electronic properties of these thin films and have found that when using an aluminum reactor chamber, the layers are contaminated with aluminum recycled from the chamber walls and electrode. This phenomenon is observed almost independently of the deposition conditions. The authors show that this contamination results in slightly p-doped films and could be detrimental to the deposition of device grade films. The authors also propose a simple way to control and eventually suppress this contamination.

  19. Amorphous diamond films

    DOE Patents [OSTI]

    Falabella, S.

    1998-06-09T23:59:59.000Z

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  20. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

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

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-11-01T23:59:59.000Z

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing,more »between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.« less

  1. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

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

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-11-01T23:59:59.000Z

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing, between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.

  2. Synthesis and characterization of inorganic silicon oxycarbide glass thin films by reactive rf-magnetron sputtering

    SciTech Connect (OSTI)

    Ryan, Joseph V.; Pantano, C. G.

    2007-01-03T23:59:59.000Z

    Silicon oxycarbide glasses have been of interest because of the potential range of properties they might exhibit through a change in carbon-to-oxygen ratio. They are metastable materials and, as such, their structures and properties are very dependent upon the synthesis method. Silicon oxycarbide bonding has been seen in materials made by melting, oxidation, polycarbosilane or sol/gel pyrolysis, and chemical vapor deposition. In this work, the radio-frequency reactive sputtering of silicon carbide targets was explored for synthesis of amorphous silicon oxycarbide thin films. SiO (2?2x) Cx films, with a continuous range of compositions where 0a SiC target. This resulted in a density range from 1.9 to 2.8 g/cm3 and a range of refractive indexes from 1.35 to 2.85. Analysis of the film compositions, structures, and properties were performed using x-ray photoelectron spectroscopy, infrared spectroscopy, nuclear magnetic resonance, profilometry, electron microscopy, grazing incidence x-ray reflectivity, and UV-visible transmission and reflection. The compositional range obtainable by this rf sputtering method is much wider than that of other synthesis methods. It is shown here that for oxygen-to-carbon ratios between *0.10 and 10.0, silicon oxycarbide bonding comprises 55%-95% of the material structure. These sputter-deposited materials were also found to have significantly less free carbon as compared to those produced by other methods. Thus, the unique properties for these novel oxycarbide materials can now be established.

  3. Characterization of Amorphous Zinc Tin Oxide Semiconductors....

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

    Amorphous Zinc Tin Oxide Semiconductors. Characterization of Amorphous Zinc Tin Oxide Semiconductors. Abstract: Amorphous zinc tin oxide (ZTO) was investigated to determine the...

  4. 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.

  5. Growth process of microcrystalline silicon studied by combined photoluminescence and Raman investigations

    SciTech Connect (OSTI)

    Klossek, A.; Mankovics, D.; Ratzke, M. [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany)] [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany); Arguirov, T.; Kittler, M. [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany) [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany); IHP Microelectronics, Im Technologiepark 25, D-15236 Frankfurt (Oder) (Germany); Kirner, S.; Gabriel, O.; Stannowski, B.; Schlatmann, R. [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany)] [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany); Friedrich, F. [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany) [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany); Department of Semiconductor Devices, Technische Universität Berlin, Sekr. E2, Einsteinufer 19, D-10587 Berlin (Germany)

    2013-12-14T23:59:59.000Z

    Plasma enhanced chemical vapor deposition of silicon on glass substrates leads to formation of silicon amorphous films with partial crystallization of nano-grains in the amorphous matrix. We studied the transition of amorphous to microcrystalline silicon during such deposition. Formation of silicon nano-grains was detected by means of photoluminescence and Raman spectroscopy. The crystalline fraction and the mean size of the nano-grains were estimated by the position and the intensity of the peaks in the Raman spectrum. We showed that the fraction of crystalline silicon in the layers and the size of the nano-grains are strongly dependent on the growth conditions. The photoluminescence spectra exhibit distinct features related to recombination in the amorphous and in the crystalline phases. A significant narrowing of the photoluminescence peak related to the amorphous phase with increasing crystalline fraction indicates a structural modification in the amorphous silicon. It suggests an ordering process occurring before the start of the actual crystallization. A peak at about 1.4 eV was associated with isolated nano-crystalline grains within the amorphous matrix. A correlation between the peak energy and grain size was found, indicating effects of carrier quantum confinement. The experimental results confirm the established theoretical models for growth of microcrystalline silicon films.

  6. Low cost routes to high purity silicon and derivatives thereof

    SciTech Connect (OSTI)

    Laine, Richard M; Krug, David James; Marchal, Julien Claudius; Mccolm, Andrew Stewart

    2013-07-02T23:59:59.000Z

    The present invention is directed to a method for providing an agricultural waste product having amorphous silica, carbon, and impurities; extracting from the agricultural waste product an amount of the impurities; changing the ratio of carbon to silica; and reducing the silica to a high purity silicon (e.g., to photovoltaic silicon).

  7. Performance of Ultrathin Silicon Solar Microcells with Nanostructures of Relief

    E-Print Network [OSTI]

    Rogers, John A.

    of the materials. Solar cells based on thin films of amorphous or polycrystalline silicon require sub- stantially, Urbana, Illinois 61801 ABSTRACT Recently developed classes of monocrystalline silicon solar microcells systems that benefit from thin construction and efficient materials utilization. KEYWORDS Nanoimprint

  8. Optimal design of one-dimensional photonic crystal back reflectors for thin-film silicon solar cells

    SciTech Connect (OSTI)

    Chen, Peizhuan; Hou, Guofu, E-mail: gfhou@nankai.edu.cn; Zhang, Jianjun, E-mail: jjzhang@nankai.edu.cn; Zhang, Xiaodan; Zhao, Ying [Institute of Photoelectronics and Tianjin Key Laboratory of Photoelectronic Thin-film Devices and Technique, Nankai University, Tianjin 300071 (China)

    2014-08-14T23:59:59.000Z

    For thin-film silicon solar cells (TFSC), a one-dimensional photonic crystal (1D PC) is a good back reflector (BR) because it increases the total internal reflection at the back surface. We used the plane-wave expansion method and the finite difference time domain (FDTD) algorithm to simulate and analyze the photonic bandgap (PBG), the reflection and the absorption properties of a 1D PC and to further explore the optimal 1D PC design for use in hydrogenated amorphous silicon (a-Si:H) solar cells. With identified refractive index contrast and period thickness, we found that the PBG and the reflection of a 1D PC are strongly influenced by the contrast in bilayer thickness. Additionally, light coupled to the top three periods of the 1D PC and was absorbed if one of the bilayers was absorptive. By decreasing the thickness contrast of the absorptive layer relative to the non-absorptive layer, an average reflectivity of 96.7% was achieved for a 1D PC alternatively stacked with a-Si:H and SiO{sub 2} in five periods. This reflectivity was superior to a distributed Bragg reflector (DBR) structure with 93.5% and an Ag film with 93.4%. n-i-p a-Si:H solar cells with an optimal 1D PC-based BR offer a higher short-circuit current density than those with a DBR-based BR or an AZO/Ag-based BR. These results provide new design rules for photonic structures in TFSC.

  9. Kinetics of dissolution and bio-availability of iron in amorphous siliceous iron oxides

    E-Print Network [OSTI]

    Seaman, John C.

    1990-01-01T23:59:59.000Z

    A&M University Chair of Advisory Committee: Dr. Richard H. Loeppert Amorphous iron (Fe) oxides are of interest because of their high reactivity, surface area, and influence on Fe availability in the soil environment. These materials may have... potential utilization as slow-release Fe amendments for calcareous soils. The objective of this study was to evaluate the impact of various concentrations of silicon (Si), present during precipitation, on the dissolution kinetics of amorphous Fe oxides...

  10. Diamond-Silicon Carbide Composite And Method For Preparation Thereof

    DOE Patents [OSTI]

    Qian, Jiang (Los Alamos, NM); Zhao, Yusheng (Los Alamos, NM)

    2005-09-06T23:59:59.000Z

    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.multidot.m.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. 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.

  11. Annealing kinetics of ^311 defects and dislocation loops in the end-of-range damage region of ion implanted silicon

    E-Print Network [OSTI]

    Florida, University of

    , University of Florida, Gainesville, Florida 32611 L. M. Rubin and J. Jackson Eaton Corporation, Beverly was implanted using an Eaton NV-GSD 200E. The wafer was amorphized using a Si implantation, with an energy of 20

  12. Thin Solid Films 430 (2003) 125129 0040-6090/03/$ -see front matter 2003 Elsevier Science B.V. All rights reserved.

    E-Print Network [OSTI]

    Deng, Xunming

    for a-Si:H solar cell fabrication. In addition to photovoltaic applications, a-Si:H is also used of amorphous silicon (a-Si:H)-based photovoltaic devices, it is important to deposit high- quality a progress has been made in hydrogenated amorphous silicon (a-Si:H)-based thin film photovoltaic devices

  13. 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.

  14. Holey Silicon as an Efficient Thermoelectric Material

    SciTech Connect (OSTI)

    Tang, Jinyao; Wang, Hung-Ta; Hyun Lee, Dong; Fardy, Melissa; Huo, Ziyang; Russell, Thomas P.; Yang, Peidong

    2010-09-30T23:59:59.000Z

    This work investigated the thermoelectric properties of thin silicon membranes that have been decorated with high density of nanoscopic holes. These ?holey silicon? (HS) structures were fabricated by either nanosphere or block-copolymer lithography, both of which are scalable for practical device application. By reducing the pitch of the hexagonal holey pattern down to 55 nm with 35percent porosity, the thermal conductivity of HS is consistently reduced by 2 orders of magnitude and approaches the amorphous limit. With a ZT value of 0.4 at room temperature, the thermoelectric performance of HS is comparable with the best value recorded in silicon nanowire system.

  15. Amorphous Diamond MEMS and Sensors

    SciTech Connect (OSTI)

    SULLIVAN, JOHN P.; FRIEDMANN, THOMAS A.; ASHBY, CAROL I.; DE BOER, MAARTEN P.; SCHUBERT, W. KENT; SHUL, RANDY J.; HOHLFELDER, ROBERT J.; LAVAN, D.A.

    2002-06-01T23:59:59.000Z

    This report describes a new microsystems technology for the creation of microsensors and microelectromechanical systems (MEMS) using stress-free amorphous diamond (aD) films. Stress-free aD is a new material that has mechanical properties close to that of crystalline diamond, and the material is particularly promising for the development of high sensitivity microsensors and rugged and reliable MEMS. Some of the unique properties of aD include the ability to easily tailor film stress from compressive to slightly tensile, hardness and stiffness 80-90% that of crystalline diamond, very high wear resistance, a hydrophobic surface, extreme chemical inertness, chemical compatibility with silicon, controllable electrical conductivity from insulating to conducting, and biocompatibility. A variety of MEMS structures were fabricated from this material and evaluated. These structures included electrostatically-actuated comb drives, micro-tensile test structures, singly- and doubly-clamped beams, and friction and wear test structures. It was found that surface micromachined MEMS could be fabricated in this material easily and that the hydrophobic surface of the film enabled the release of structures without the need for special drying procedures or the use of applied hydrophobic coatings. Measurements using these structures revealed that aD has a Young's modulus of {approx}650 GPa, a tensile fracture strength of 8 GPa, and a fracture toughness of 8 MPa{center_dot}m {sup 1/2}. These results suggest that this material may be suitable in applications where stiction or wear is an issue. Flexural plate wave (FPW) microsensors were also fabricated from aD. These devices use membranes of aD as thin as {approx}100 nm. The performance of the aD FPW sensors was evaluated for the detection of volatile organic compounds using ethyl cellulose as the sensor coating. For comparable membrane thicknesses, the aD sensors showed better performance than silicon nitride based sensors. Greater than one order of magnitude increase in chemical sensitivity is expected through the use of ultra-thin aD membranes in the FPW sensor. The discoveries and development of the aD microsystems technology that were made in this project have led to new research projects in the areas of aD bioMEMS and aD radio frequency MEMS.

  16. High-Rate Fabrication of a-Si-Based Thin-Film Solar Cells Using Large-Area VHF PECVD Processes

    SciTech Connect (OSTI)

    Deng, Xunming [University of Toledo] [University of Toledo; Fan, Qi Hua

    2011-12-31T23:59:59.000Z

    The University of Toledo (UT), working in concert with it’s a-Si-based PV industry partner Xunlight Corporation (Xunlight), has conducted a comprehensive study to develop a large-area (3ft x 3ft) VHF PECVD system for high rate uniform fabrication of silicon absorber layers, and the large-area VHF PECVD processes to achieve high performance a-Si/a-SiGe or a-Si/nc-Si tandem junction solar cells during the period of July 1, 2008 to Dec. 31, 2011, under DOE Award No. DE-FG36-08GO18073. The project had two primary goals: (i) to develop and improve a large area (3 ft × 3 ft) VHF PECVD system for high rate fabrication of > = 8 Å/s a-Si and >= 20 Å/s nc-Si or 4 Å/s a-SiGe absorber layers with high uniformity in film thicknesses and in material structures. (ii) to develop and optimize the large-area VHF PECVD processes to achieve high-performance a-Si/nc-Si or a-Si/a-SiGe tandem-junction solar cells with >= 10% stable efficiency. Our work has met the goals and is summarized in “Accomplishments versus goals and objectives”.

  17. Nanostructural characterization of amorphous diamondlike carbon films

    SciTech Connect (OSTI)

    SIEGAL,MICHAEL P.; TALLANT,DAVID R.; MARTINEZ-MIRANDA,L.J.; BARBOUR,J. CHARLES; SIMPSON,REGINA L.; OVERMYER,DONALD L.

    2000-01-27T23:59:59.000Z

    Nanostructural characterization of amorphous diamondlike carbon (a-C) films grown on silicon using pulsed-laser deposition (PLD) is correlated to both growth energetic and film thickness. Raman spectroscopy and x-ray reflectivity probe both the topological nature of 3- and 4-fold coordinated carbon atom bonding and the topographical clustering of their distributions within a given film. In general, increasing the energetic of PLD growth results in films becoming more ``diamondlike'', i.e. increasing mass density and decreasing optical absorbance. However, these same properties decrease appreciably with thickness. The topology of carbon atom bonding is different for material near the substrate interface compared to material within the bulk portion of an a-C film. A simple model balancing the energy of residual stress and the free energies of resulting carbon topologies is proposed to provide an explanation of the evolution of topographical bonding clusters in a growing a-C film.

  18. Deposition of a-SiC:H using organosilanes in an argon/hydrogen plasma

    SciTech Connect (OSTI)

    Maya, L.

    1993-12-01T23:59:59.000Z

    Selected organosilanes were examined as precursors for the deposition of amorphous hydrogenated silicon carbide in an argon/hydrogen plasma. Effect of process variables on the quality of the films was established by means of FTIR, Auger spectroscopy, XPS, XRD, chemical analysis, and weight losses upon pyrolysis. For a given power level there is a limiting feeding rate of the precursor under which operation of the system is dominated by thermodynamics and leads to high quality silicon carbide films that are nearly stoichiometric and low in hydrogen. Beyond that limit, carbosilane polymer formation and excessive hydrogen incorporation takes place. The hydrogen content of the plasma affects the deposition rate and the hydrogen content of the film. In the thermodynamically dominated regime the nature of the precursor has no effect on the quality of the film, it affects only the relative utilization efficiency.

  19. Structure and Transformation of Amorphous Calcium Carbonate:...

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

    Transformation of Amorphous Calcium Carbonate: A Solid-State 43Ca NMR and Computational Molecular Dynamics Structure and Transformation of Amorphous Calcium Carbonate: A...

  20. Silicon-germanium saturable absorbers and erbium-doped waveguides for integrated mode-locked lasers

    E-Print Network [OSTI]

    Byun, Hyunil

    2006-01-01T23:59:59.000Z

    In this thesis, Silicon-Germanium (SiGe) Saturable Bragg Reflectors (SBR) and Erbium-doped waveguide chips are fabricated and characterized as crucial components for integration of a mode-locked laser on a Si-chip. The ...

  1. Metallic coatings on silicon substrates, and methods of forming metallic coatings on silicon substrates

    DOE Patents [OSTI]

    Branagan, Daniel J. (Idaho Falls, ID); Hyde, Timothy A. (Idaho Falls, ID); Fincke, James R. (Los Alamos, NM)

    2008-03-11T23:59:59.000Z

    The invention includes methods of forming a metallic coating on a substrate which contains silicon. A metallic glass layer is formed over a silicon surface of the substrate. The invention includes methods of protecting a silicon substrate. The substrate is provided within a deposition chamber along with a deposition target. Material from the deposition target is deposited over at least a portion of the silicon substrate to form a protective layer or structure which contains metallic glass. The metallic glass comprises iron and one or more of B, Si, P and C. The invention includes structures which have a substrate containing silicon and a metallic layer over the substrate. The metallic layer contains less than or equal to about 2 weight % carbon and has a hardness of at least 9.2 GPa. The metallic layer can have an amorphous microstructure or can be devitrified to have a nanocrystalline microstructure.

  2. Carbon-Silicon Core-Shell Nanowires as High Capacity Electrode for Lithium

    E-Print Network [OSTI]

    Cui, Yi

    Carbon-Silicon Core-Shell Nanowires as High Capacity Electrode for Lithium Ion Batteries Li lithium battery electrodes. Amorphous silicon was coated onto carbon nanofibers to form a core during lithium cycling and can function as a mechanical support and an efficient electron conducting

  3. CMOS-compatible, athermal silicon ring modulators clad with titanium dioxide

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    CMOS-compatible, athermal silicon ring modulators clad with titanium dioxide Stevan S. Djordjevic,1-optic contribution with that from the amorphous titanium dioxide (a-TiO2) overcladding with a negative thermo-compatible Titanium Dioxide Deposition for Athermalization of Silicon Waveguides," accepted for publication

  4. Two-and three-dimensional folding of thin film single-crystalline silicon for photovoltaic

    E-Print Network [OSTI]

    Lewis, Jennifer

    Two- and three-dimensional folding of thin film single-crystalline silicon for photovoltaic power of a functional, nonpla- nar photovoltaic (PV) device. A mechanics model based on the theory of thin plates self-folding photovoltaics capillary force Silicon, in crystalline and amorphous forms, is currently

  5. Atmospheric ageing of nanosized silicon nitride powders Janos Szepvolgyi,*a

    E-Print Network [OSTI]

    Gubicza, Jenõ

    . Introduction Silicon nitride powders produced in high temperature thermal plasmas by the vapour phase reaction of silicon tetrachloride and ammonia have many interesting properties including high purity, mainly amorphous powders subjected to atmospheric ageing, including amino, hydroxy and silanol groups, adsorbed CO2

  6. Amorphous metal alloy and composite

    DOE Patents [OSTI]

    Wang, Rong (Richland, WA); Merz, Martin D. (Richland, WA)

    1985-01-01T23:59:59.000Z

    Amorphous metal alloys of the iron-chromium and nickel-chromium type have excellent corrosion resistance and high temperature stability and are suitable for use as a protective coating on less corrosion resistant substrates. The alloys are stabilized in the amorphous state by one or more elements of titanium, zirconium, hafnium, niobium, tantalum, molybdenum, and tungsten. The alloy is preferably prepared by sputter deposition.

  7. Scattering Properties of nanostructures : applications to photovoltaics

    E-Print Network [OSTI]

    Derkacs, Daniel

    2009-01-01T23:59:59.000Z

    hydrogen during deposition, dangling bonds are compensated and hydrogenated amorphous silicon (a-Si:H) can be made into a promising photovoltaic

  8. Compositions of corrosion-resistant Fe-based amorphous metals suitable for producing thermal spray coatings

    DOE Patents [OSTI]

    Farmer, Joseph C.; Wong, Frank M. G.; Haslam, Jeffery J.; Ji, Xiaoyan (Jane); Day, Sumner D.; Blue, Craig A.; Rivard, John D. K.; Aprigliano, Louis F.; Kohler, Leslie K.; Bayles, Robert; Lemieux, Edward J.; Yang, Nancy; Perepezko, John H.; Kaufman, Larry; Heuer, Arthur; Lavernia, Enrique J.

    2013-07-09T23:59:59.000Z

    A method of coating a surface comprising providing a source of amorphous metal that contains manganese (1 to 3 atomic %), yttrium (0.1 to 10 atomic %), and silicon (0.3 to 3.1 atomic %) in the range of composition given in parentheses; and that contains the following elements in the specified range of composition given in parentheses: chromium (15 to 20 atomic %), molybdenum (2 to 15 atomic %), tungsten (1 to 3 atomic %), boron (5 to 16 atomic %), carbon (3 to 16 atomic %), and the balance iron; and applying said amorphous metal to the surface by a spray.

  9. Compositions of corrosion-resistant Fe-based amorphous metals suitable for producing thermal spray coatings

    DOE Patents [OSTI]

    Farmer, Joseph C; Wong, Frank M.G.; Haslam, Jeffery J; Ji, Xiaoyan; Day, Sumner D; Blue, Craig A; Rivard, John D.K.; Aprigliano, Louis F; Kohler, Leslie K; Bayles, Robert; Lemieux, Edward J; Yang, Nancy; Perepezko, John H; Kaufman, Larry; Heuer, Arthur; Lavernia, Enrique J

    2013-09-03T23:59:59.000Z

    A method of coating a surface comprising providing a source of amorphous metal that contains manganese (1 to 3 atomic %), yttrium (0.1 to 10 atomic %), and silicon (0.3 to 3.1 atomic %) in the range of composition given in parentheses; and that contains the following elements in the specified range of composition given in parentheses: chromium (15 to 20 atomic %), molybdenum (2 to 15 atomic %), tungsten (1 to 3 atomic %), boron (5 to 16 atomic %), carbon (3 to 16 atomic %), and the balance iron; and applying said amorphous metal to the surface by a spray.

  10. Method of making selective crystalline silicon regions containing entrapped hydrogen by laser treatment

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    A novel hydrogen rich single crystalline 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 crystalline silicon without out-gasing the hydrogen. The new material can be used to fabricate semi-conductor devices such as single crystalline silicon solar cells with surface window regions having a greater band gap energy than that of single crystalline silicon without hydrogen.

  11. Patterning of hydrogenated microcrystalline silicon growth by magnetic field

    SciTech Connect (OSTI)

    Fejfar, A.; Stuchlik, J.; Mates, T.; Ledinsky, M.; Honda, S.; Kocka, J. [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague 6 (Czech Republic)

    2005-07-04T23:59:59.000Z

    A way of influencing growth of silicon films by magnetic field is demonstrated. Permanent magnet(s) placed under the substrate influenced the discharge in a mixture of silane and hydrogen and led to formation of microcrystalline regions in otherwise amorphous film. The pattern of microcrystalline regions varied with the orientation of the magnetic field. Microscopic study by atomic force microscopy and by micro-Raman spectroscopy revealed that the microcrystalline regions resulted from a higher density of crystalline grain nuclei, increased at the locations where the magnetron effect could be expected. This phenomenon could be used to study the transition between amorphous and microcrystalline growth. Moreover, we suggest it as a kind of 'magnetic lithography' for the preparation of predefined microcrystalline patterns in otherwise amorphous silicon films.

  12. Amorphous silicon thin film transistor as nonvolatile device.

    E-Print Network [OSTI]

    Nominanda, Helinda

    2008-10-10T23:59:59.000Z

    layer all of which are exposed to the radiation source during operation.62 Under the high dose x-ray irradiation, the TFT needs to be electrically biased or thermally annealed in order to perform the switching function effectively.59 For the extra...-terrestrial use, the gamma ray is naturally abundant in the cosmic space. Gamma-ray is more energetic than the x-ray. An x-ray has longer wavelength than a gamma ray, i.e., 10-0.1 nm vs. gamma ray irradiation can result in different photoelectron...

  13. 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.

  14. amorphous silicon oxide: Topics by E-print Network

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

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

  15. 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 ...

  16. The specific heat of pure and hydrogenated amorphous silicon

    E-Print Network [OSTI]

    Queen, Daniel Robert

    2011-01-01T23:59:59.000Z

    by turning off the heater with a step function. The 2mWby turning on the heater with a current step as well as 5 ?sample heater current was incremented in 0.5µA steps for a

  17. Structure of Pentacene Monolayers on Amorphous Silicon Oxide and Relation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure of All-Polymer Solar Cells ImpedesStructure ofHumanto Charge

  18. Atomic Layer Deposition for Stabilization of Amorphous Silicon Anodes |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureComments from Tarasa U.S.LLCEnergyEnergyAtomic Energy Act

  19. Mechanics of amorphous polymers and polymer gels

    E-Print Network [OSTI]

    Chester, Shawn Alexander

    2011-01-01T23:59:59.000Z

    Many applications of amorphous polymers require a thermo-mechanically coupled large-deformation elasto-viscoplasticity theory which models the strain rate and temperature dependent response of amorphous polymeric materials ...

  20. Glass nanoimprint using amorphous Ni-P mold etched by focused-ion beam

    SciTech Connect (OSTI)

    Mekaru, Harutaka; Kitadani, Takeshi; Yamashita, Michiru; Takahashi, Masaharu [National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1, Namiki, Tsukuba, Ibaraki 305-8564 (Japan); SAWA Plating Co., Ltd., 753 Hoshiro, Himeji, Hyogo 670-0804 (Japan); Hyogo Prefectural Institute of Technology, 3-1-12 Yukihira-cho, Suma-ku, Kobe 654-0037 (Japan); National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564 (Japan)

    2007-07-15T23:59:59.000Z

    The authors succeeded in glass-nanoimprint lithography of micropatterns and nanopatterns using an amorphous Ni-P alloy mold. Glasslike carbon has been used as a mold material to mold not only Pyrex glass but also quartz, because it is still stable at a temperature of 1650 deg. C. However, it is difficult to process glasslike carbon substrates into arbitrary shapes by machining. They thought that amorphous Ni-P alloy could be used as a mold material for industrial glass molding. If Ni is electroless plated when mixed with suitable amount of P on a Si wafer, the Ni-P alloy layer becomes amorphous. An appropriate ratio of Ni and P was determined by the results of x-ray-diffraction measurements. The optimized composition ratio of Ni-P was Ni:P=92:8 wt %. Moreover, line and space patterns and dot arrays with linewidths of as little as 500 nm were etched on the mold using focused-ion beam (FIB) and the processing accuracy for the amorphous Ni-P layer was compared with that for the pure Ni layer. The result was that patterns of 500 nm width were etched to a depth of 2 {mu}m on an amorphous Ni-P alloy mold and the processed surfaces were smooth. In contrast, in the case of the pure Ni layer, the processing line was notched and the sidewalls were very rough. The crystal grain seems to hinder the processing of the nanopattern. After FIB etching, the amorphous Ni-P alloy was thermally treated at 400 deg. C to improve the hardness. Finally, line and space patterns and dot arrays on the amorphous Ni-P alloy mold were nanoimprinted on Pyrex glass using a glass-nanoimprint system (ASHE0201) that National Institute of Advanced Industrial Science and Technology developed.

  1. Hybrid Silicon Nanocone-Polymer Solar Cells Sangmoo Jeong,

    E-Print Network [OSTI]

    Cui, Yi

    ABSTRACT: Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices solar cell. Additionally, about 26% of the module cost comes from the fabrication processes of a SiHybrid Silicon Nanocone-Polymer Solar Cells Sangmoo Jeong, Erik C. Garnett, Shuang Wang, Zongfu Yu

  2. OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR Xunming Deng

    E-Print Network [OSTI]

    Deng, Xunming

    OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR CELLS Xunming Deng Department cells, all employing high- quality a-SiGe cells, are reviewed in this paper. Incorporating various improvements in device fabrication, the UT group fabricated 1) triple-junction a-Si/a-SiGe/a- SiGe solar cells

  3. Spatially selective single-grain silicon films induced by hydrogen plasma seeding

    E-Print Network [OSTI]

    small holes. The solid-phase crystallization SPC of amorphous sili- con involves two steps, i- ation of a-Si:H SPC, such as metal-induced SPC,5 germanium-induced SPC,6 ion-beam-induced SPC,7 and plasma-induced SPC.8,9 Although the original motivation of these methods was to reduce the thermal budget

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

    SciTech Connect (OSTI)

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

    2008-08-04T23:59:59.000Z

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

  5. Pulsed energy synthesis and doping of silicon carbide

    DOE Patents [OSTI]

    Truher, J.B.; Kaschmitter, J.L.; Thompson, J.B.; Sigmon, T.W.

    1995-06-20T23:59:59.000Z

    A method for producing beta silicon carbide thin films by co-depositing thin films of amorphous silicon and carbon onto a substrate is disclosed, whereafter the films are irradiated by exposure to a pulsed energy source (e.g. excimer laser) to cause formation of the beta-SiC compound. Doped beta-SiC may be produced by introducing dopant gases during irradiation. Single layers up to a thickness of 0.5-1 micron have been produced, with thicker layers being produced by multiple processing steps. Since the electron transport properties of beta silicon carbide over a wide temperature range of 27--730 C is better than these properties of alpha silicon carbide, they have wide application, such as in high temperature semiconductors, including HETEROJUNCTION-junction bipolar transistors and power devices, as well as in high bandgap solar arrays, ultra-hard coatings, light emitting diodes, sensors, etc.

  6. Pulsed energy synthesis and doping of silicon carbide

    DOE Patents [OSTI]

    Truher, Joel B. (San Rafael, CA); Kaschmitter, James L. (Pleasanton, CA); Thompson, Jesse B. (Brentwood, CA); Sigmon, Thomas W. (Beaverton, OR)

    1995-01-01T23:59:59.000Z

    A method for producing beta silicon carbide thin films by co-depositing thin films of amorphous silicon and carbon onto a substrate, whereafter the films are irradiated by exposure to a pulsed energy source (e.g. excimer laser) to cause formation of the beta-SiC compound. Doped beta-SiC may be produced by introducing dopant gases during irradiation. Single layers up to a thickness of 0.5-1 micron have been produced, with thicker layers being produced by multiple processing steps. Since the electron transport properties of beta silicon carbide over a wide temperature range of 27.degree.-730.degree. C. is better than these properties of alpha silicon carbide, they have wide application, such as in high temperature semiconductors, including hetero-junction bipolar transistors and power devices, as well as in high bandgap solar arrays, ultra-hard coatings, light emitting diodes, sensors, etc.

  7. Glow-discharge synthesis of silicon nitride precursor powders

    SciTech Connect (OSTI)

    Ho, P.; Buss, R.J.; Loehman, R.E. (Sandia National Laboratories, Albuquerque, New Mexico 87185-5800 (US))

    1989-07-01T23:59:59.000Z

    A radio-frequency glow discharge is used for the synthesis of submicron, amorphous, silicon nitride precursor powders from silane and ammonia. Powders are produced with a range of Si/N ratios, including stoichiometric, Si-rich, and N-rich, and contain substantial amounts of hydrogen. The powders appear to be similar to silicon diimide and are easily converted to oxide by water vapor. The powders lose weight and crystallize to a mixture of {alpha} and {beta}-Si{sub 3}N{sub 4} after prolonged heating at 1600{degree}C. Studies of spectrally and spatially resolved optical emission from the plasma are reported.

  8. Infrared Spectroscopy and Optical Constants of Porous Amorphous...

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

    Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Infrared Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Abstract: Reflection-absorption...

  9. amorphous polyethylene terephthalate: Topics by E-print Network

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

    Index 1 Solid State Blending of Poly(ethylene terephthalate) with Polystyrene: Extent of PET Amorphization and Chemistry Websites Summary: compatibilizers. CMA also amorphized the...

  10. Formation of Supercooled Liquid Solutions from Nanoscale Amorphous...

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

    Supercooled Liquid Solutions from Nanoscale Amorphous Solid Films of Methanol and Ethanol. Formation of Supercooled Liquid Solutions from Nanoscale Amorphous Solid Films of...

  11. Electron-Stimulated Production of Molecular Oxygen in Amorphous...

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

    Water. Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water. Abstract: The low-energy, electron-stimulated production of molecular oxygen from pure amorphous...

  12. amorphous silica dissolution: Topics by E-print Network

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

    A SEMICONDUCTEUR AMORPHE Physics Websites Summary: for amorphous semiconduc- tor test vehicles, and for reliable electronic components. REVUE DE PHYSIQUE APPLIQU?E...

  13. Atomic-Level Simulations of Epitaxial Recrystallization andAmorphous...

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

    Simulations of Epitaxial Recrystallization and Amorphous-to-Crystalline Transition in 4H-SiC. Atomic-Level Simulations of Epitaxial Recrystallization and Amorphous-to-Crystalline...

  14. amorphous carbon substrates: Topics by E-print Network

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

    CaF2 films on amorphous substrates Wang, Gwo-Ching 5 NICKELHYDROGENATED AMORPHOUS CARBON COMPOSITE FILMS DEPOSITED IN ACETYLENEARGON MICROWAVE PLASMA DISCHARGE CiteSeer...

  15. Improved Stability Of Amorphous Zinc Tin Oxide Thin Film Transistors...

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

    Stability Of Amorphous Zinc Tin Oxide Thin Film Transistors Using Molecular Passivation. Improved Stability Of Amorphous Zinc Tin Oxide Thin Film Transistors Using Molecular...

  16. Growth mechanisms study of microcrystalline silicon deposited by SiH{sub 4}/H{sub 2} plasma using tailored voltage waveforms

    SciTech Connect (OSTI)

    Bruneau, B., E-mail: bastien.bruneau@polytechnique.edu; Johnson, E. V. [LPICM-CNRS, Ecole Polytechnique, route de Saclay, 91128 Palaiseau (France); Wang, J. [LPICM-CNRS, Ecole Polytechnique, route de Saclay, 91128 Palaiseau (France); ICARE China-Europe Institute for Clean and Renewable Energy at Huazhong University of Science and Technology, 1037 Luoyu Road, 430074 Wuhan (China); Dornstetter, J.-C. [LPICM-CNRS, Ecole Polytechnique, route de Saclay, 91128 Palaiseau (France); TOTAL New Energies, 24 cours Michelet, 92069 Paris La Défense Cedex (France)

    2014-02-28T23:59:59.000Z

    The use of Tailored Voltage Waveforms is a technique wherein one uses non-sinusoidal waveforms with a period equivalent to RF frequencies to excite a plasma. It has been shown to be an effective technique to decouple maximum Ion Bombardment Energy (IBE) from the ion flux at the surface of the electrodes. In this paper, we use it for the first time as a way to scan through the IBE in order to study the growth mechanism of hydrogenated microcrystalline silicon using a SiH{sub 4}/H{sub 2} chemistry. We find that at critical energies, a stepwise increase in the amorphous to microcrystalline transition thickness is observed, as detected by Real Time Spectroscopic Ellipsometry. The same energy thresholds (30?eV and 70?eV) are found to be very influential on the final surface morphology of the samples, as observed by Atomic Force Microscopy. These thresholds correspond to SiH{sub x}{sup +} bulk displacement (30?eV) and H{sub x}{sup +} (70?eV) surface displacement energies. A model is therefore proposed to account for the impact of these ions on the morphology of ?c-Si:H growth.

  17. Nanoscale photon management in silicon solar cells Sangmoo Jeong, Shuang Wang, and Yi Cui

    E-Print Network [OSTI]

    Cui, Yi

    and replication of butterfly wings for photovoltaic application J. Vac. Sci. Technol. A 30, 01A146 (2012) High-efficiency (2012) Amorphous and nanocrystalline silicon thin film photovoltaic technology on flexible substrates J. Technol. A 29, 061201 (2011) Photovoltaic manufacturing: Present status, future prospects, and research

  18. Crystallization and phase transformations in amorphous NiTi thin films for microelectromechanical systems

    SciTech Connect (OSTI)

    Lee, Hoo-Jeong; Ramirez, Ainissa G. [Department of Mechanical Engineering, Yale University, New Haven, Connecticut 06520 (United States)

    2004-08-16T23:59:59.000Z

    Amorphous sputtered nickel-titanium thin films were deposited onto micromachined silicon-nitride membranes and subjected to heating and cooling conditions. Their associated microstructure was monitored directly and simultaneously with in situ transmission electron microscopy. These electron-transparent membranes constrained the NiTi films and rendered it possible for observation of the complete transformation cycle, which includes: the crystallization of the amorphous phase to austenite phase (cubic B2 structure) with heating; and the conversion of austenite (B2) to martensite (monoclinic B19{sup '} structure) with cooling. Electron micrographs show the nucleation and growth of grains occurs at a temperature of 470 deg. C and at a rate that indicates a polymorphic transformation. The onset of martensitic transformation occurs between 25 and 35 deg. C. Calorimetric measurements are consistent with the observed crystallization.

  19. CVD of refractory amorphous metal alloys

    SciTech Connect (OSTI)

    Tenhover, M. [The Carborundum Co., Niagara Falls, NY (United States). Technology Div.

    1995-08-01T23:59:59.000Z

    In this work, a novel process is described for the fabrication of multi-metallic amorphous metal alloy coatings using a chemical vapor deposition (CVD) technique. Of special interest in this work are amorphous metal alloys containing Mo and/or Cr which have high crystallization temperatures and readily available low decomposition temperature metal-bearing precursors. The conditions for amorphous alloy formation via CVD are described as well as the chemical properties of these materials. High temperature, aqueous corrosion tests have shown these materials (especially those containing Cr) are among the most corrosion resistant metal alloys known.

  20. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    DOE Patents [OSTI]

    Farmer, Joseph C. (Tracy, CA); Wong, Frank M. G. (Livermore, CA); Haslam, Jeffery J. (Livermore, CA); Yang, Nancy (Lafayette, CA); Lavernia, Enrique J. (Davis, CA); Blue, Craig A. (Knoxville, TN); Graeve, Olivia A. (Reno, NV); Bayles, Robert (Annandale, VA); Perepezko, John H. (Madison, WI); Kaufman, Larry (Brookline, MA); Schoenung, Julie (Davis, CA); Ajdelsztajn, Leo (Walnut Creek, CA)

    2009-11-17T23:59:59.000Z

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  1. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    DOE Patents [OSTI]

    Farmer, Joseph C.; Wong, Frank M.G.; Haslam, Jeffery J.; Yang, Nancy; Lavernia, Enrique J.; Blue, Craig A.; Graeve, Olivia A.; Bayles, Robert; Perepezko, John H.; Kaufman, Larry; Schoenung, Julie; Ajdelsztajn, Leo

    2014-07-15T23:59:59.000Z

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  2. a-si alloy solar: Topics by E-print Network

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

    Last Page Topic Index 1 OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR Xunming Deng Renewable Energy Websites Summary: OPTIMIZATION OF a-SiGe BASED TRIPLE,...

  3. Modelling morphogenesis as an amorphous computation

    E-Print Network [OSTI]

    Bhattacharyya, Arnab

    2006-01-01T23:59:59.000Z

    This thesis presents a programming-language viewpoint for morphogenesis, the process of shape formation during embryological development. We model morphogenesis as a self-organizing, self-repairing amorphous computation ...

  4. Purified silicon production system

    DOE Patents [OSTI]

    Wang, Tihu; Ciszek, Theodore F.

    2004-03-30T23:59:59.000Z

    Method and apparatus for producing purified bulk silicon from highly impure metallurgical-grade silicon source material at atmospheric pressure. Method involves: (1) initially reacting iodine and metallurgical-grade silicon to create silicon tetraiodide and impurity iodide byproducts in a cold-wall reactor chamber; (2) isolating silicon tetraiodide from the impurity iodide byproducts and purifying it by distillation in a distillation chamber; and (3) transferring the purified silicon tetraiodide back to the cold-wall reactor chamber, reacting it with additional iodine and metallurgical-grade silicon to produce silicon diiodide and depositing the silicon diiodide onto a substrate within the cold-wall reactor chamber. The two chambers are at atmospheric pressure and the system is open to allow the introduction of additional source material and to remove and replace finished substrates.

  5. a-si alloy production: Topics by E-print Network

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

    for silicon metal comes primarily from the aluminum and chemical industries. Domestic secondary aluminum production--the primary materials source for aluminum-silicon alloys--was...

  6. European Photovoltaic Solar Energy Conference, Valencia, Spain, 6-10 September 2010, 2AO.2.3 EFFECT OF SiN DEPOSITION TEMPERATURE ON SURFACE PASSIVATION OF N-TYPE CZ SILICON

    E-Print Network [OSTI]

    25th European Photovoltaic Solar Energy Conference, Valencia, Spain, 6-10 September 2010, 2AO.2N deposition leads to increasing the hydrogen content of the SiN layers. This improves the supply of hydrogen silicon using thermally grown oxide or amorphous films based on hydrogenated silicon compounds has been

  7. Method of making selective crystalline silicon regions containing entrapped hydrogen by laser treatment

    DOE Patents [OSTI]

    Pankove, J.I.; Wu, C.P.

    1982-03-30T23:59:59.000Z

    A novel hydrogen rich single crystalline 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 crystalline silicon without out-gassing the hydrogen. The new material can be used to fabricate semi-conductor devices such as single crystalline silicon solar cells with surface window regions having a greater band gap energy than that of single crystalline silicon without hydrogen. 2 figs.

  8. Formation and crystallization of silicon nanoclusters in SiN{sub x}:H films using femtosecond pulsed laser annealings

    SciTech Connect (OSTI)

    Korchagina, T. T., E-mail: Taisiya999@mail.ru; Volodin, V. A., E-mail: volodin@isp.nsc.ru [Russian Academy of Sciences, A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation); Chichkov, B. N. [Laser Zentrum Hannover e.V. (Germany)

    2010-12-15T23:59:59.000Z

    SiN{sub x}:H films of different compositions grown on glass and silicon substrates using plasma-chemical vapor deposition at a temperature of 380 deg. C have been subjected to pulsed laser annealings. The treatments are performed using titanium-sapphire laser radiation with a wavelength of 800 nm and a pulse duration of 30 fs. Structural changes in the films are studied using Raman spectroscopy. Amorphous silicon nanoclusters are detected in as-grown films with molar fractions of excess silicon of {approx}1/5 and larger. Conditions required for pulsed crystallization of nanoclusters were determined. According to the Raman data, no silicon clusters were detected in as-grown films with a small amount of excess silicon (x > 1.25). Pulsed treatments resulted in the formation of silicon nanoclusters 1-2 nm in size in these films.

  9. Effects of surface pretreatments on interface structure during formation of ultra-thin yttrium silicate dielectric films on silicon

    E-Print Network [OSTI]

    Garfunkel, Eric

    silicate dielectric films on silicon J. J. Chambers Department of Chemical Engineering, North Carolina indicates that the yttrium silicate films are amorphous with uniform contrast throughout the layer. MEIS (10 Ã?) SiO2 film and oxidized, a yttrium silicate film is formed with bonding and composition similar

  10. Controlled epitaxial graphene growth within removable amorphous carbon corrals

    SciTech Connect (OSTI)

    Palmer, James; Hu, Yike; Hankinson, John; Guo, Zelei; Heer, Walt A. de [School of Physics, Georgia Institute of Technology, 837 State St. NW, Atlanta, Georgia 30332 (United States); Kunc, Jan [School of Physics, Georgia Institute of Technology, 837 State St. NW, Atlanta, Georgia 30332 (United States); Faculty of Mathematics and Physics, Institute of Physics, 12116 Prague (Czech Republic); Berger, Claire [School of Physics, Georgia Institute of Technology, 837 State St. NW, Atlanta, Georgia 30332 (United States); Université Grenoble Alpes/CNRS—Institut Néel, BP166, Grenoble Cedex 9 38042 (France)

    2014-07-14T23:59:59.000Z

    We address the question of control of the silicon carbide (SiC) steps and terraces under epitaxial graphene on SiC and demonstrate amorphous carbon (aC) corrals as an ideal method to pin SiC surface steps. aC is compatible with graphene growth, structurally stable at high temperatures, and can be removed after graphene growth. For this, aC is first evaporated and patterned on SiC, then annealed in the graphene growth furnace. There at temperatures above 1200?°C, mobile SiC steps accumulate at the aC corral that provide effective step flow barriers. Aligned step free regions are thereby formed for subsequent graphene growth at temperatures above 1330?°C. Atomic force microscopy imaging supports the formation of step-free terraces on SiC with the step morphology aligned to the aC corrals. Raman spectroscopy indicates the presence of good graphene sheets on the step-free terraces.

  11. 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.

  12. Chapter 6 Simulations of Amorphous Polyethylene Glass Transition

    E-Print Network [OSTI]

    Goddard III, William A.

    112 Chapter 6 Simulations of Amorphous Polyethylene Glass Transition 6.1 Introduction Amorphous and characterized. Although various macroscopic properties around and below the glass transition temperature have been extensively investigated experimentally, the phenomena of glass transition and relaxation

  13. Fabrication of amorphous metal matrix composites by severe plastic deformation

    E-Print Network [OSTI]

    Mathaudhu, Suveen Nigel

    2006-10-30T23:59:59.000Z

    by equal channel angular extrusion (ECAE) for consolidation of bulk amorphous metals (BAM) and amorphous metal matrix composites (AMMC) is investigated in this dissertation. The objectives of this research are a) to better understand processing parameters...

  14. Direct Evidence of Lithium-Induced Atomic Ordering in Amorphous...

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

    Evidence of Lithium-Induced Atomic Ordering in Amorphous TiO2 Nanotubes . Direct Evidence of Lithium-Induced Atomic Ordering in Amorphous TiO2 Nanotubes . Abstract: In this paper,...

  15. Thermal conductivity of sputtered amorphous Ge films

    SciTech Connect (OSTI)

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)] [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2014-02-15T23:59:59.000Z

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids.

  16. amorphous carbon deposited: Topics by E-print Network

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

    The contamination was believed 2 NICKELHYDROGENATED AMORPHOUS CARBON COMPOSITE FILMS DEPOSITED IN ACETYLENEARGON MICROWAVE PLASMA DISCHARGE CiteSeer Summary:...

  17. Cathode encapsulation of organic light emitting diodes by atomic layer deposited Al{sub 2}O{sub 3} films and Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks

    SciTech Connect (OSTI)

    Keuning, W.; Weijer, P. van de; Lifka, H.; Kessels, W. M. M.; Creatore, M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Philips Research Laboratories, High Tech Campus 4, P.O. Box WAG12, 5656 AE Eindhoven (Netherlands); Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2012-01-15T23:59:59.000Z

    Al{sub 2}O{sub 3} thin films synthesized by plasma-enhanced atomic layer deposition (ALD) at room temperature (25 deg. C) have been tested as water vapor permeation barriers for organic light emitting diode devices. Silicon nitride films (a-SiN{sub x}:H) deposited by plasma-enhanced chemical vapor deposition served as reference and were used to develop Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks. On the basis of Ca test measurements, a very low intrinsic water vapor transmission rate of {<=} 2 x 10{sup -6} g m{sup -2} day{sup -1} and 4 x 10{sup -6} g m{sup -2} day{sup -1} (20 deg. C/50% relative humidity) were found for 20-40 nm Al{sub 2}O{sub 3} and 300 nm a-SiN{sub x}:H films, respectively. The cathode particle coverage was a factor of 4 better for the Al{sub 2}O{sub 3} films compared to the a-SiN{sub x}:H films and an average of 0.12 defects per cm{sup 2} was obtained for a stack consisting of three barrier layers (Al{sub 2}O{sub 3}/a-SiN{sub x}:H/Al{sub 2}O{sub 3}).

  18. Enhanced catalyst-free nucleation of GaN nanowires on amorphous Al{sub 2}O{sub 3} by plasma-assisted molecular beam epitaxy

    SciTech Connect (OSTI)

    Sobanska, Marta, E-mail: sobanska@ifpan.edu.pl; Klosek, Kamil; Borysiuk, Jolanta; Kret, Slawomir; Tchutchulasvili, Giorgi; Gieraltowska, Sylwia; Zytkiewicz, Zbigniew R. [Institute of Physics Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2014-01-28T23:59:59.000Z

    We report on plasma-assisted molecular beam epitaxial growth of GaN nanowires (NWs) on Si(111) substrates with a thin amorphous Al{sub 2}O{sub 3} buffer layer deposited by atomic layer deposition. Comparison of nucleation kinetics shows that presence of amorphous Al{sub 2}O{sub 3} buffer significantly enhances spontaneous nucleation of GaN NWs. Slower nucleation was observed on partially amorphous silicon nitride films. No growth of NWs was found on sapphire substrate under the same growth conditions which we explain by a low density of defects on monocrystalline substrate surface where NWs may nucleate. Our finding shows that tuning of substrate microstructure is an efficient tool to control rate of self-induced nucleation of GaN NWs.

  19. Niobium Silicon alloys for Kinetic Inductance Detectors

    E-Print Network [OSTI]

    Calvo, M; Monfardini, A; Benoit, A; Boudou, N; Bourrion, O; Catalano, A; Dumoulin, L; Goupy, J; Sueur, H Le; Marnieros, S

    2013-01-01T23:59:59.000Z

    We are studying the properties of Niobium Silicon amorphous alloys as a candidate material for the fabrication of highly sensitive Kinetic Inductance Detectors (KID), optimized for very low optical loads. As in the case of other composite materials, the NbSi properties can be changed by varying the relative amounts of its components. Using a NbSi film with T_c around 1 K we have been able to obtain the first NbSi resonators, observe an optical response and acquire a spectrum in the band 50 to 300 GHz. The data taken show that this material has very high kinetic inductance and normal state surface resistivity. These properties are ideal for the development of KID. More measurements are planned to further characterize the NbSi alloy and fully investigate its potential.

  20. Sonochemically Prepared Nanostructured Amorphous Molybdenum Sulfide

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    . CLASSIFICATION form: amorphous, nanostructured fine powder function: hydrodesulfurization catalyst, lubricant and energy diffusion out of the bubble. As a result, extreme temperatures and pressures are achieved within/s. These unique and severe conditions can be used to drive chemical reactions within the bubble; one result

  1. Silicon rich nitride for silicon based laser devices

    E-Print Network [OSTI]

    Yi, Jae Hyung

    2008-01-01T23:59:59.000Z

    Silicon based light sources, especially laser devices, are the key components required to achieve a complete integrated silicon photonics system. However, the fundamental physical limitation of the silicon material as light ...

  2. SiGe quantum dot single-hole transistor fabricated by atomic force microscope nanolithography and silicon epitaxial-regrowth

    E-Print Network [OSTI]

    Rokhinson, Leonid

    SiGe quantum dot single-hole transistor fabricated by atomic force microscope nanolithography; published online 10 November 2006 A SiGe quantum dot single-hole transistor passivated by silicon epitaxial are reproducible, in sharp contrast with the noisy and irreproducible I-V characteristics of unpassivated SiGe

  3. Functionalized Silicone Nanospheres: Synthesis, Transition Metal...

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

    Functionalized Silicone Nanospheres: Synthesis, Transition Metal Immobilization, and Catalytic Applications. Functionalized Silicone Nanospheres: Synthesis, Transition Metal...

  4. Effect of Heat Treatment on Silicon Carbide Based Joining Materials for Fusion Energy

    SciTech Connect (OSTI)

    Lewinsohn, Charles A.; Jones, Russell H.; Nozawa, T.; Kotani, M.; Kishimoto, H.; Katoh, Y.; Kohyama, A.

    2001-10-01T23:59:59.000Z

    Two general approaches to obtaining silicon carbide-based joint materials were used. The first method relies on reactions between silicon and carbon to form silicon carbide, or to bond silicon carbide powders together. The second method consists of pyrolysing a polycarbosilane polymer to yield an amorphous, covalently bonded material. In order to assess the long-term durability of the joint materials, various heat treatments were performed and the effects on the mechanical properties of the joints were measured. Although the joints derived from the polycarbosilane polymer were not the strongest, the value of strength measured was not affected by heat treatment. On the other hand, the value of the strength of the reaction-based joints was affected by heat treatment, indicating the presence of residual stresses or unreacted material subsequent to processing. Further investigation of reaction-based joining should consist of detailed microscopic studies; however, continued study of joints derived from polymers is also warranted.

  5. Micromachined silicon electrostatic chuck

    DOE Patents [OSTI]

    Anderson, Robert A. (Albuquerque, NM); Seager, Carleton H. (Albuquerque, NM)

    1996-01-01T23:59:59.000Z

    An electrostatic chuck is faced with a patterned silicon plate 11, created y micromachining a silicon wafer, which is attached to a metallic base plate 13. Direct electrical contact between the chuck face 15 (patterned silicon plate's surface) and the silicon wafer 17 it is intended to hold is prevented by a pattern of flat-topped silicon dioxide islands 19 that protrude less than 5 micrometers from the otherwise flat surface of the chuck face 15. The islands 19 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 15 and wafer 17 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 19 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 15, typically 0.5 to 5 percent. The pattern of the islands 19, together with at least one hole 12 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. 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.

  7. Building Integrated Photovoltaics: New trends and Challenges'

    E-Print Network [OSTI]

    Painter, Kevin

    AR coating p-type Si Monocrystalline Silicon solar cell Polycrystalline wafer solar cells #12;· Thin crystalline silicon (mono & multi) Dye cell and organic thin film: a-Si, CdTe, CIGS new concepts the optical absorption in thin a-Si layers, texturing of TCO and reflecting mirror are applied Amorphous

  8. Solar cells utilizing pulsed-energy crystallized microcrystalline/polycrystalline silicon

    DOE Patents [OSTI]

    Kaschmitter, James L. (Pleasanton, CA); Sigmon, Thomas W. (Beaverton, OR)

    1995-01-01T23:59:59.000Z

    A process for producing multi-terminal devices such as solar cells wherein a pulsed high energy source is used to melt and crystallize amorphous silicon deposited on a substrate which is intolerant to high processing temperatures, whereby to amorphous silicon is converted into a microcrystalline/polycrystalline phase. Dopant and hydrogenization can be added during the fabrication process which provides for fabrication of extremely planar, ultra shallow contacts which results in reduction of non-current collecting contact volume. The use of the pulsed energy beams results in the ability to fabricate high efficiency microcrystalline/polycrystalline solar cells on the so-called low-temperature, inexpensive plastic substrates which are intolerant to high processing temperatures.

  9. Solar cells utilizing pulsed-energy crystallized microcrystalline/polycrystalline silicon

    DOE Patents [OSTI]

    Kaschmitter, J.L.; Sigmon, T.W.

    1995-10-10T23:59:59.000Z

    A process for producing multi-terminal devices such as solar cells wherein a pulsed high energy source is used to melt and crystallize amorphous silicon deposited on a substrate which is intolerant to high processing temperatures, whereby the amorphous silicon is converted into a microcrystalline/polycrystalline phase. Dopant and hydrogenation can be added during the fabrication process which provides for fabrication of extremely planar, ultra shallow contacts which results in reduction of non-current collecting contact volume. The use of the pulsed energy beams results in the ability to fabricate high efficiency microcrystalline/polycrystalline solar cells on the so-called low-temperature, inexpensive plastic substrates which are intolerant to high processing temperatures.

  10. Wear Resistant Amorphous and Nanocomposite Coatings

    SciTech Connect (OSTI)

    Racek, O

    2008-03-26T23:59:59.000Z

    Glass forming materials (critical cooling rate <10{sup 4}K.s{sup -1}) are promising for their high corrosion and wear resistance. During rapid cooling, the materials form an amorphous structure that transforms to nanocrystalline during a process of devitrification. High hardness (HV 1690) can be achieved through a controlled crystallization. Thermal spray process has been used to apply coatings, which preserves the amorphous/nanocomposite structure due to a high cooling rate of the feedstock particles during the impact on a substrate. Wear properties have been studied with respect to process conditions and feedstock material properties. Application specific properties such as sliding wear resistance have been correlated with laboratory tests based on instrumented indentation and scratch tests.

  11. Two-dimensional defects in amorphous materials

    E-Print Network [OSTI]

    Michael Moshe; Eran Sharon; Ido Levin; Hillel Aharoni; Raz Kupferman

    2014-09-09T23:59:59.000Z

    We present a new definition of defects which is based on a Riemannian formulation of incompatible elasticity. Defects are viewed as local deviations of the material's reference metric field, $\\bar{\\mathfrak{g}}$, from a Euclidian metric. This definition allows the description of defects in amorphous materials and the formulation of the elastic problem, using a single field, $\\bar{\\mathfrak{g}}$. We provide a multipole expansion of reference metrics that represent a large family of two-dimensional (2D) localized defects. The case of a dipole, which corresponds to an edge dislocation is studied analytically, experimentally and numerically. The quadrupole term, which is studied analytically, as well as higher multipoles of curvature carry local deformations. These multipoles are good candidates for fundamental strain carrying entities in plasticity theories of amorphous materials and for a continuous modeling of recently developed meta-materials.

  12. UNIVERSITE PARIS-SUD COLE DOCTORALE : STITS

    E-Print Network [OSTI]

    of hydrogenated amorphous silicon is presented with the focus on its application in photovoltaic devices. Chapter of the reliability and validity of this approach applied to a-Si:H Schottky barriers with various magnitudes

  13. Charge detection in semiconductor nanostructures

    E-Print Network [OSTI]

    MacLean, Kenneth (Kenneth MacLean, III)

    2010-01-01T23:59:59.000Z

    In this thesis nanometer scale charge sensors are used to study charge transport in two solid state systems: Lateral GaAs quantum dots and hydrogenated amorphous silicon (a-Si:H). In both of these experiments we use ...

  14. Synthesis of new amorphous metallic spin glasses

    DOE Patents [OSTI]

    Haushalter, R.C.

    1985-02-11T23:59:59.000Z

    Disclosed are: amorphous metallic precipitates having the formula (M/sub 1/)/sub a/(M/sub 2/)/sub b/ wherein M/sub 1/ is at least one transition metal, M/sub 2/ is at least one main group metal and the integers ''a'' and ''b'' provide stoichiometric balance; the precipitates having a degree of local order characteristic of chemical compounds from the precipitation process and useful electrical and mechanical properties.

  15. Synthesis of new amorphous metallic spin glasses

    DOE Patents [OSTI]

    Haushalter, Robert C. (Clinton, NJ)

    1988-01-01T23:59:59.000Z

    Amorphous metallic precipitates having the formula (M.sub.1).sub.a (M.sub.2).sub.b wherein M.sub.1 is at least one transition metal, M.sub.2 is at least one main group metal and the integers "a" and "b" provide stoichiometric balance; the precipitates having a degree of local order characteristic of chemical compounds from the precipitation process and useful electrical and mechanical properties.

  16. 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.

  17. Electrical detection of spin echoes for phosphorus donors in silicon

    E-Print Network [OSTI]

    Hans Huebl; Felix Hoehne; Benno Grolik; Andre R. Stegner; Martin Stutzmann; Martin S. Brandt

    2007-12-02T23:59:59.000Z

    The electrical detection of spin echoes via echo tomography is used to observe decoherence processes associated with the electrical readout of the spin state of phosphorus donor electrons in silicon near a SiO$_2$ interface. Using the Carr-Purcell pulse sequence, an echo decay with a time constant of $1.7\\pm0.2 \\rm{\\mu s}$ is observed, in good agreement with theoretical modeling of the interaction between donors and paramagnetic interface states. Electrical spin echo tomography thus can be used to study the spin dynamics in realistic spin qubit devices for quantum information processing.

  18. Laser micro-processing of silicon using nanosecond pulse shaped fibre laser at 1 ?m wavelength

    E-Print Network [OSTI]

    Li, Kun

    2012-06-12T23:59:59.000Z

    ). ............................................................................... 11 Figure 2.2(a): Schematic and (b) SEM image of 19.8% efficient multicrystalline silicon solar cell with “honeycomb” surface texturing (Zhao, Wang et al. 1998). (c) The “inverted pyramid” texture on the top surface (Zhao, Wang et al. 1995). (d) A... is 40 µm (Tan 2006). (c): SEM image of silicon machined by frequency tripled Nd: YAG laser (355 nm) followed by cleaning in the KOH solution (Chen and Darling 2005). (d) Profiles and SEM images (×1.5 k) of ablated a-Si under different irradiation...

  19. Amorphous Molecular Organic Solids for Gas Adsorption. | EMSL

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

    Molecular Organic Solids for Gas Adsorption. Amorphous Molecular Organic Solids for Gas Adsorption. Abstract: We show that molecular organic compounds with large accessible...

  20. Probing the Interaction of Amorphous Solid Water on a Hydrophobic...

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

    Surface: Dewetting and Crystallization Kinetics of ASW on Abstract: Desorption of carbon tetrachloride from beneath an amorphous solid water (ASW) overlayer is explored...

  1. Electron-Stimulated Production of Molecular Oxygen in Amorphous...

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

    Water on Pt(111): Precursor Transport Through the Hydrogen Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water on Pt(111): Precursor Transport Through the...

  2. Electron-beam induced recrystallization in amorphous apatite...

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

    recrystallization observed in the present study. Citation: Bae IT, Y Zhang, WJ Weber, M Higuchi, and L Giannuzzi.2007."Electron-beam induced recrystallization in amorphous...

  3. Ionization-induced effects in amorphous apatite at elevated temperatur...

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

    of the structural contrast features, respectively. Citation: Bae IT, Y Zhang, WJ Weber, M Ishimaru, Y Hirotsu, and M Higuchi.2008."Ionization-induced effects in amorphous...

  4. Amorphous layer coating induced brittle to ductile transition...

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

    layer coating induced brittle to ductile transition in single crystalline SiC nanowires: an atomistic simulation. Amorphous layer coating induced brittle to ductile transition in...

  5. amorphous hard carbon: Topics by E-print Network

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

    in hard and elastic amorphous carbon nitride films investigated H NMR spectroscopy Materials Science Websites Summary: Received 14 February 2003; published 5 November 2003 The...

  6. amorphous diamond films: Topics by E-print Network

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

    simulations of the nanometer-scale indentation of amorphous-carbon thin films Materials Science Websites Summary: , and lattice constants of both solid-state diamond and...

  7. Optical absorption in silicon layers in the presence of charge inversion/accumulation or ion implantation

    SciTech Connect (OSTI)

    Alloatti, L.; Lauermann, M.; Koos, C.; Freude, W. [Institutes IPQ and IMT, Karlsruhe Institute of Technology (KIT), Karlsruhe 76131 (Germany)] [Institutes IPQ and IMT, Karlsruhe Institute of Technology (KIT), Karlsruhe 76131 (Germany); Sürgers, C. [Physikalisches Institut and DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology, P. O. Box 6980, Karlsruhe 76049 (Germany)] [Physikalisches Institut and DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology, P. O. Box 6980, Karlsruhe 76049 (Germany); Leuthold, J. [Institutes IPQ and IMT, Karlsruhe Institute of Technology (KIT), Karlsruhe 76131 (Germany) [Institutes IPQ and IMT, Karlsruhe Institute of Technology (KIT), Karlsruhe 76131 (Germany); Institute of Electromagnetic Fields (IFH), ETH Zurich, Zurich (Switzerland)

    2013-07-29T23:59:59.000Z

    We determine the optical losses in gate-induced charge accumulation/inversion layers at a Si/SiO{sub 2} interface. Comparison between gate-induced charge layers and ion-implanted thin silicon films having an identical sheet resistance shows that optical losses can be significantly lower for gate-induced layers. For a given sheet resistance, holes produce higher optical loss than electrons. Measurements have been performed at ? = 1550 nm.

  8. Dual energy imaging in mammography: Cross-talk study in a Si array detector

    E-Print Network [OSTI]

    Ramello, Luciano

    Dual energy imaging in mammography: Cross-talk study in a Si array detector G. Baldazzi a , D-monochromatic peaks are shown in Fig. 1. 2. Experimental setup The apparatus for dual energy mammography

  9. Annealing Simulations of Nano-Sized Amorphous Structures in SiC...

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

    Simulations of Nano-Sized Amorphous Structures in SiC. Annealing Simulations of Nano-Sized Amorphous Structures in SiC. Abstract: A two-dimensional model of a nano-sized amorphous...

  10. Improvement of pin-type amorphous silicon solar cell performance by employing double silicon-carbide p-layer structure

    E-Print Network [OSTI]

    Kim, Yong Jung

    structure, and slow deposition rate improves the open-circuit voltage (Voc), short-circuit current density- proves the FF, as well as considerably enhances Voc and the short-circuit current density (Jsc). Thus through use of this buffer layer, the open-circuit voltage (Voc) and short-wavelength response could

  11. amorphous solid water: Topics by E-print Network

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

    amorphous solid water First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Phase diagram of amorphous solid...

  12. amorphous molecular materials: Topics by E-print Network

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

    amorphous molecular materials First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 New amorphous forms of...

  13. LOW-TEMPERATURE CRYSTALLIZATION OF AMORPHOUS SILICATE IN ASTROPHYSICAL ENVIRONMENTS

    SciTech Connect (OSTI)

    Tanaka, Kyoko K.; Yamamoto, Tetsuo [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Kimura, Hiroshi [Center for Planetary Science, Kobe 657-8501 (Japan)

    2010-07-01T23:59:59.000Z

    We construct a theoretical model for low-temperature crystallization of amorphous silicate grains induced by exothermic chemical reactions. As a first step, the model is applied to the annealing experiments, in which the samples are (1) amorphous silicate grains and (2) amorphous silicate grains covered with an amorphous carbon layer. We derive the activation energies of crystallization for amorphous silicate and amorphous carbon from the analysis of the experiments. Furthermore, we apply the model to the experiment of low-temperature crystallization of an amorphous silicate core covered with an amorphous carbon layer containing reactive molecules. We clarify the conditions of low-temperature crystallization due to exothermic chemical reactions. Next, we formulate the crystallization conditions so as to be applicable to astrophysical environments. We show that the present crystallization mechanism is characterized by two quantities: the stored energy density Q in a grain and the duration of the chemical reactions {tau}. The crystallization conditions are given by Q>Q{sub min} and {tau} < {tau}{sub cool} regardless of details of the reactions and grain structure, where {tau}{sub cool} is the cooling timescale of the grains heated by exothermic reactions, and Q{sub min} is minimum stored energy density determined by the activation energy of crystallization. Our results suggest that silicate crystallization occurs in wider astrophysical conditions than hitherto considered.

  14. Constitutive model for plasticity in an amorphous polycarbonate A. Fortunelli

    E-Print Network [OSTI]

    Ortiz, Michael

    Constitutive model for plasticity in an amorphous polycarbonate A. Fortunelli Molecular Modeling response of an amorphous glassy polycarbonate is proposed. The model is based on an isotropic elastic phase glassy polycarbonate. DOI: 10.1103/PhysRevE.76.041806 PACS number s : 61.41. e, 46.35. z, 46.15. x, 83

  15. Glutamate Surface Speciation on Amorphous Titanium Dioxide and

    E-Print Network [OSTI]

    Sverjensky, Dimitri A.

    Glutamate Surface Speciation on Amorphous Titanium Dioxide and Hydrous Ferric Oxide D I M I T R I (HFO) and titanium dioxide exhibit similar strong attachment of many adsorbates including biomolecules on amorphous titanium dioxide. The results indicate that glutamate adsorbs on HFO as a deprotonated divalent

  16. Pentagonal puckering in a sheet of amorphous graphene

    E-Print Network [OSTI]

    Thorpe, Michael

    Pentagonal puckering in a sheet of amorphous graphene Y. Li 1 , F. Inam 2 , Avishek Kumar 3 , M. F 2011 Published online 13 July 2011 Keywords amorphous graphene, density functional theory, fullerenes Ordered graphene has been extensively studied. In this paper, we undertake a density functional study

  17. Structural Characteristics of Synthetic Amorphous Calcium Carbonate

    SciTech Connect (OSTI)

    Michel, F. Marc; MacDonald, Jason; Feng, Jian; Phillips, Brian L.; Ehm, Lars; Tarabrella, Cathy; Parise, John B.; Reeder, Richard J. (SBU)

    2008-08-06T23:59:59.000Z

    Amorphous calcium carbonate (ACC) is an important phase involved in calcification by a wide variety of invertebrate organisms and is of technological interest in the development of functional materials. Despite widespread scientific interest in this phase a full characterization of structure is lacking. This is mainly due to its metastability and difficulties in evaluating structure using conventional structure determination methods. Here we present new findings from the application of two techniques, pair distribution function analysis and nuclear magnetic resonance spectroscopy, which provide new insight to structural aspects of synthetic ACC. Several important results have emerged from this study of ACC formed in vitro using two common preparation methods: (1) ACC exhibits no structural coherence over distances > 15 {angstrom} and is truly amorphous; (2) most of the hydrogen in ACC is present as structural H{sub 2}O, about half of which undergoes restricted motion on the millisecond time scale near room temperature; (3) the short- and intermediate-range structure of ACC shows no distinct match to any known structure in the calcium carbonate system; and (4) most of the carbonate in ACC is monodentate making it distinctly different from monohydrocalcite. Although the structure of synthetic ACC is still not fully understood, the results presented provide an important baseline for future experiments evaluating biogenic ACC and samples containing certain additives that may play a role in stabilization of ACC, crystallization kinetics, and final polymorph selection.

  18. Salt Fog Testing Iron-Based Amorphous Alloys

    SciTech Connect (OSTI)

    Rebak, Raul B. [Chemistry and Materials Science, Lawrence Livermore National Laboratory, 7000 East Ave, L- 631, Livermore, CA, 94550 (United States); Aprigliano, Louis F. [Consultant, Berlin, MD, 21811 (United States); Day, S. Daniel; Farmer, Joseph C. [LLNL, Livermore, CA, 94550 (United States)

    2007-07-01T23:59:59.000Z

    Iron-based amorphous alloys are hard and highly corrosion resistant, which make them desirable for salt water and other applications. These alloys can be produced as powder and can be deposited as coatings on any surface that needs to be protected from the environment. It was of interest to examine the behavior of these amorphous alloys in the standard salt-fog testing ASTM B 117. Three different amorphous coating compositions were deposited on 316L SS coupons and exposed for many cycles of the salt fog test. Other common engineering alloys such as 1018 carbon steel, 316L SS and Hastelloy C-22 were also tested together with the amorphous coatings. Results show that amorphous coatings are resistant to rusting in salt fog. Partial devitrification may be responsible for isolated rust spots in one of the coatings. (authors)

  19. 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 ...

  20. Use of additives to improve microstructures and fracture resistance of silicon nitride ceramics

    DOE Patents [OSTI]

    Becher, Paul F. (Oak Ridge, TN); Lin, Hua-Tay (Oak Ridge, TN)

    2011-06-28T23:59:59.000Z

    A high-strength, fracture-resistant silicon nitride ceramic material that includes about 5 to about 75 wt-% of elongated reinforcing grains of beta-silicon nitride, about 20 to about 95 wt-% of fine grains of beta-silicon nitride, wherein the fine grains have a major axis of less than about 1 micron; and about 1 to about 15 wt-% of an amorphous intergranular phase comprising Si, N, O, a rare earth element and a secondary densification element. The elongated reinforcing grains have an aspect ratio of 2:1 or greater and a major axis measuring about 1 micron or greater. The elongated reinforcing grains are essentially isotropically oriented within the ceramic microstructure. The silicon nitride ceramic exhibits a room temperature flexure strength of 1,000 MPa or greater and a fracture toughness of 9 MPa-m.sup.(1/2) or greater. The silicon nitride ceramic exhibits a peak strength of 800 MPa or greater at 1200 degrees C. Also included are methods of making silicon nitride ceramic materials which exhibit the described high flexure strength and fracture-resistant values.

  1. 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.

  2. Reduced Light-Induced Degradation in a Si:H: The Role of Network Nanostructure

    SciTech Connect (OSTI)

    Stradins, P.; Bobela, D. C.; Branz, H. M.

    2011-01-01T23:59:59.000Z

    In this work, we report our recent observations on strong reduction in Staebler-Wronski (SWE) effect in device quality a-Si:H that has been post-deposition annealed up to 400C, and make a connection between these observations and changes in a-Si:H network nanostructure and H bonding, both from our own FTIR and NMR measurements and from the SAXS and NMR literature. The results suggest that it is the smallest (atomic size) voids in a-Si:H that are most likely responsible for the Staebler-Wronski effect. Thermal treatments up to 400C lead to coalescence and restructuring of these voids leading to reduction of SWE.

  3. 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).

  4. 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.

  5. Dynamics of Consolidation and Crack Growth in Nanocluster-Assembled Amorphous Silicon Nitride

    E-Print Network [OSTI]

    Southern California, University of

    -angle distributions in crystalline Si3N4 are in excellent agreement with neutron scattering measurements;8 (ii) the po agreement with neutron scattering experiments;9 (iii) the phonon density-of-states and the temperature

  6. Short-and intermediate-range structural correlations in amorphous silicon carbide: A molecular dynamics study

    E-Print Network [OSTI]

    Southern California, University of

    with the presence of structural defects. For this purpose inelastic neutron-scattering and neutron- diffraction Federal de São Carlos, São Carlos, SP, Brazil 3 Studsvik Neutron Research Laboratory, University

  7. High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells

    E-Print Network [OSTI]

    Deng, Xunming

    . The figure also shows the short circuit current under UT simulator and AM1.5 spectrum. Figure 3-3 IV curve. Table 5-4 Open circuit voltage of the 42 samples fabricated to map out the phase diagram #12;5 Section 1

  8. A MODEL OF THE RECRYSTALLIZATION MECHANISM OF AMORPHOUS SILICON LAYERS CREATED BY ION IMPLANTATION

    E-Print Network [OSTI]

    Drosd, R.M.

    2010-01-01T23:59:59.000Z

    in Physical Metallurgy", p. 282, ASM Monogram, (1950). 35.Solid State Theory in Metallurgy (Cambridge Press, 1973), p.

  9. amorphous silicon-carbon alloys: Topics by E-print Network

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

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

  10. amorphous-silicon solar cells: Topics by E-print Network

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

    state of affairs Schiff, Eric A. 19 Fully Solution-Processed Copper Chalcopyrite Thin Film Solar Cells: Materials Chemistry, Processing, and Device Physics University of...

  11. amorphous-silicon-based solar cell: Topics by E-print Network

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

    Pankaj J Edla; Dr. Bhupendra Gupta 89 Fully Solution-Processed Copper Chalcopyrite Thin Film Solar Cells: Materials Chemistry, Processing, and Device Physics University of...

  12. amorphous-silicon-based thin-film photovoltaic: Topics by E-print...

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

    devices have been obtained by a direct polymerization of undoped (or p-type doped) thin film (CH)x layer onto a polycrystalline cadmium sulfide film Paris-Sud XI, Universit...

  13. Application of Thin-Film Amorphous Silicon to Chemical Imaging Tatsuo Yoshinobu1

    E-Print Network [OSTI]

    Moritz, Werner

    is a field-effect sensor with an electrolyte-insulator-semiconductor (EIS) structure as shown in figure 1. A dc bias voltage is applied to the EIS system so that a depletion layer is induced at the insulator of the LAPS is similar to that of the EIS capacitance sensor [4,5], in which the capacitance of the EIS system

  14. Formation of molecular hydrogen on amorphous silicate surfaces

    E-Print Network [OSTI]

    Ling Li; Giulio Manico; Emanuele Congiu; Joe Roser; Sol Swords; Hagai B. Perets; Adina Lederhendler; Ofer Biham; John Robert Brucato; Valerio Pirronello; Gianfranco Vidali

    2007-09-16T23:59:59.000Z

    Experimental results on the formation of molecular hydrogen on amorphous silicate surfaces are presented and analyzed using a rate equation model. The energy barriers for the relevant diffusion and desorption processes are obtained. They turn out to be significantly higher than those obtained for polycrystalline silicates, demonstrating the importance of grain morphology. Using these barriers we evaluate the efficiency of molecular hydrogen formation on amorphous silicate grains under interstellar conditions. It is found that unlike polycrystalline silicates, amorphous silicate grains are efficient catalysts of H_2 formation in diffuse interstellar clouds.

  15. Fabrication of porous silicon membranes 

    E-Print Network [OSTI]

    Yue, Wing Kong

    1988-01-01T23:59:59.000Z

    . Porous silicon layer is formed by the local dissolution which is initiated by the surface layer and is promoted by the hindrance layers composed of the silicic acid. Local etching or local dissolution is the cause of forming porous structure... of pores were 25 to 45 A with a mean value of 38 A. Microstructure of porous silicon studied by Besle et al. showed two distinct 17 patterns: the structure pattern of porous silicon film on heavily doped silicon and that on slightly doped silicon [26...

  16. Process For Direct Integration Of A Thin-Film Silicon P-N Junction Diode With A Magnetic Tunnel Junction

    DOE Patents [OSTI]

    Toet, Daniel (Mountain View, CA); Sigmon, Thomas W. (Albuquerque, NM)

    2005-08-23T23:59:59.000Z

    A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

  17. Process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction

    DOE Patents [OSTI]

    Toet, Daniel (Mountain View, CA); Sigmon, Thomas W. (Albuquerque, NM)

    2003-01-01T23:59:59.000Z

    A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

  18. Process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction

    DOE Patents [OSTI]

    Toet, Daniel; Sigmon, Thomas W.

    2004-12-07T23:59:59.000Z

    A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

  19. Advanced Design of Broadband Distributed Amplifier using a SiGe BiCMOS Technology

    E-Print Network [OSTI]

    De Flaviis, Franco

    interfaces, it is essential that RF/microwave circuits be implemented in low-cost silicon technology. However.18 µm CMOS distributed amplifier with Coplanar Strip (CPS) was designed with the unity gain

  20. Back channel etch chemistry of advanced a-Si:H TFTs , T.K. Won b

    E-Print Network [OSTI]

    Kanicki, Jerzy

    been reported in the etch- ing of silicon for various applications [15,16]. Fluorocarbon com- pounds organic etching by- product common in fluorocarbon dry etching process [18,19]. Hydrogen bromide (HBr) has

  1. Side-Jump Effect in Paramagnetic Amorphous Metals

    E-Print Network [OSTI]

    RHIE, K.; Naugle, Donald G.; O, BH; MARKERT, JT.

    1993-01-01T23:59:59.000Z

    A systematic study of the resistivity (rho), the Hall coefficients (R(H)), and the magnetic susceptibilities (chi) of the Zr-based paramagnetic amorphous alloys suggests a self-consistent explanation for the frequently observed positive values of R...

  2. Amorphous powders of Al-Hf prepared by mechanical alloying

    SciTech Connect (OSTI)

    Schwarz, R.B.; Hannigan, J.W.; Sheinberg, H.; Tiainen, T.

    1988-01-01T23:59:59.000Z

    We synthesized amorphous Al/sub 50/Hf/sub 50/ alloy powder by mechanically alloying an equimolar mixture of crystalline powders of Al and Hf using hexane as a dispersant. We characterized the powder as a function of mechanical-alloying time by scanning electron microscopy, x-ray diffraction, and differential scanning calorimetry. Amorphous Al/sub 50/Hf/sub 50/ powder heated at 10 K s/sup /minus/1/ crystallizes polymorphously at 1003 K into orthorhombic AlHf (CrB-type structure). During mechanical alloying, some hexane decomposes and hydrogen and carbon are incorporated into the amorphous alloy powder. The hydrogen can be removed by annealing the powder by hot pressing at a temperature approximately 30 K below the crystallization temperature. The amorphous compacts have a diamond pyramidal hardness of 1025 DPH. 24 refs., 7 figs., 1 tab.

  3. Atomistic simulations of radiation damage in amorphous metal alloys

    E-Print Network [OSTI]

    Baumer, Richard E. (Richard Edward)

    2013-01-01T23:59:59.000Z

    While numerous fundamental studies have characterized the atomic-level radiation response mechanisms in irradiated crystalline alloys, comparatively little is known regarding the mechanisms of radiation damage in amorphous ...

  4. The Release of Trapped Gases from Amorphous Solid Water Films...

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

    I. Top-Down" Crystallization-Induced Crack Propagation Probed The Release of Trapped Gases from Amorphous Solid Water Films: I. Top-Down" Crystallization-Induced Crack Propagation...

  5. amorphous carbon films: Topics by E-print Network

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

    constants of both solid-state diamond and graphite and gas-phase hydro- carbon materials.19Atomistic simulations of the nanometer-scale indentation of amorphous-carbon thin...

  6. amorphous carbon film: Topics by E-print Network

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

    constants of both solid-state diamond and graphite and gas-phase hydro- carbon materials.19Atomistic simulations of the nanometer-scale indentation of amorphous-carbon thin...

  7. Theory and simulation of amorphous organic electronic devices

    E-Print Network [OSTI]

    Madigan, Conor (Conor Francis), 1978-

    2006-01-01T23:59:59.000Z

    The electronic properties of amorphous organic thin films are of great interest due to their application in devices such as light emitting devices, solar cells, photodetectors, and lasers. Compared to conventional inorganic ...

  8. Electrodeposition of amorphous matrix Ni-W/Wp̳ composites

    E-Print Network [OSTI]

    Jenket, Donald R. (Donald Robert)

    2005-01-01T23:59:59.000Z

    An amorphous Ni-W alloy matrix was incorporated with W particulate through two types of electrodeposition. The plating bath for the electrodeposition contained nickel sulfate, sodium tungstate, sodium citrate, ammonium ...

  9. FORMATION OF A PHYSICALLY STABLE AMORPHOUS DRUG COMPLEX

    E-Print Network [OSTI]

    MacLean, Jenifer Anne

    2010-12-16T23:59:59.000Z

    ABSTRACT In this paper we explore the use of Neusilin, an inorganic magnesium aluminometasilicate, to stabilize the amorphous form of an acidic drug a neutral drug and two basic drugs. Both cryomilling and ball milling of ...

  10. Quasi-Reversible Oxygen Exchange of Amorphous IGZO Thin Films

    E-Print Network [OSTI]

    Shahriar, Selim

    MRSEC Quasi-Reversible Oxygen Exchange of Amorphous IGZO Thin Films NSF Grant # 1121262 A. U. Adler Center In situ electrical properties of a-IGZO thin films were carried out at 200ºC as a function/"defect" structure of amorphous oxide films. In situ conductivity of 70 nm a-IGZO thin film at 200oC measured in van

  11. Pressure-induced transformations in amorphous Si-Ge alloy

    SciTech Connect (OSTI)

    Coppari, F.; Polian, A.; Menguy, N.; Trapananti, A.; Congeduti, A.; Newville, M.; Prakapenka, V.B.; Choi, Y.; Principi, E.; Di Cicco, A. (CNRS-UMR); (UC); (Camerino)

    2012-03-14T23:59:59.000Z

    The pressure behavior of an amorphous Si-rich SiGe alloy ({alpha}-Si{sub x}Ge{sub 1-x}, x = 0.75) has been investigated up to about 30 GPa, by a combination of Raman spectroscopy, x-ray absorption spectroscopy, and x-ray diffraction measurements. The trends of microscopic structural properties and of the Raman-active phonon modes are presented in the whole pressure range. Nucleation of nanocrystalline alloy particles and metallization have been observed above 12 GPa, with a range of about 2 GPa of coexistence of amorphous and crystalline phases. Transformations from the amorphous tetrahedral, to the crystalline tetragonal ({beta}-Sn) and to the simple hexagonal structures have been observed around 13.8 and 21.8 GPa. The recovered sample upon depressurization, below about 4 GPa, shows a local structure similar to the as-deposited one. Inhomogeneities of the amorphous texture at the nanometric scale, probed by high-resolution transmission electron microscopy, indicate that the recovered amorphous sample has a different ordering at this scale, and therefore the transformations can not be considered fully reversible. The role of disordered grain boundaries at high pressure and the possible presence of a high-density amorphous phase are discussed.

  12. Pressure-induced amorphous-to-amorphous reversible transformation in Pr{sub 75}Al{sub 25}

    SciTech Connect (OSTI)

    Lin, C. L.; Ahmad, A. S.; Lou, H. B.; Wang, X. D.; Cao, Q. P.; Jiang, J. Z. [International Center for New-Structured Materials and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Li, Y. C.; Liu, J.; Hu, T. D. [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhang, D. X. [State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027 (China)

    2013-12-07T23:59:59.000Z

    A pressure-induced amorphous-to-amorphous reversible transformation was revealed in Pr{sub 75}Al{sub 25} metallic glass (MG) using in situ high-pressure synchrotron x-ray diffraction technique. The transition began at about 21?GPa with a???5% volume collapse and ended at about 35?GPa. This transition is reversible with hysteresis. Based on the high-pressure behaviors of Ce-based metallic glasses and Pr metal here, we suggest that the pressure-induced polyamorphic transition in Pr{sub 75}Al{sub 25} MG stems from 4f-electron delocalization of Pr metal which leads to abrupt change in bond shortening. These results obtained here provide new insights into the underlying mechanism of the amorphous-to-amorphous phase transition in metallic glasses and will trigger more theoretical and experimental investigations for such transition.

  13. 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

  14. Use of silicon in liquid sintered silicon nitrides and sialons

    DOE Patents [OSTI]

    Raj, Rishi (Ithaca, NY); Baik, Sunggi (Ithaca, NY)

    1984-12-11T23:59:59.000Z

    This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.

  15. Use of silicon in liquid sintered silicon nitrides and sialons

    DOE Patents [OSTI]

    Raj, R.; Baik, S.

    1984-12-11T23:59:59.000Z

    This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic. 4 figs.

  16. Identifying electronic properties relevant to improving stability in a-Si:H-based cells and overall performance in a-Si,Ge:H-based cells. Annual subcontract report, 18 April 1995--17 April 1996

    SciTech Connect (OSTI)

    Cohen, J.D. [Oregon Univ., Eugene, OR (United States)

    1997-03-01T23:59:59.000Z

    The work done during this second phase of the University of Oregon`s NREL subcontract focused on degradation studies in both pure a-Si:H and a-Si,Ge:H alloys, as well as a detailed study of the interface between these two materials in a-Si:H/a-Si, Ge:H heterostructures. All samples discussed in this report were produced by the glow-discharge method and were obtained either in collaboration with United Solar Systems Corporation or with researchers at Lawrence Berkeley laboratory. First, the results from the a-Si, Ge:H degradation studies support the conclusion that considerable quantities of charged defects exist in nominally intrinsic material. Researchers found that on light-soaking, all the observed defect sub-bands increased; however, their ratios varied significantly. Second, researchers performed voltage pulse stimulated capacitance transient measurements on a-Si:H/a-Si, Ge:H heterostructure samples and found a clear signature of trapped hole emission extending over long times. Finally, researchers began comparison studies of the electronic properties of a-Si:H grown by glow discharge either with 100% silane, or with silane diluted in H{sub 2} or He gas. The results on these samples indicate that the films grown under high hydrogen dilution exhibit roughly a factor of 3 lower deep defect densities than those grown using pure silane.

  17. JOURNAL DE PHYSIQUE CoZZoque C4, suppZdment au nOIO, Tome 42, octobre 1981 page C4-463

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    EFFICIENCY, LARGE-AREA PHOTOVOLTAIC DEVICES USING AMORPHOUS Si:F:H ALLOY A. Madan, W. Czubatyj, J. Yang, J, U. S.A. Abstract.- Overall conversion efficiency of 6.6% has been obtained for a photovoltaic device.- The possibility of low-cost thin film photovoltaic cells using amorphous silicon (a-Si) based alloys has generated

  18. 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.

  19. Low temperature production of large-grain polycrystalline semiconductors

    DOE Patents [OSTI]

    Naseem, Hameed A. (Fayetteville, AR); Albarghouti, Marwan (Loudonville, NY)

    2007-04-10T23:59:59.000Z

    An oxide or nitride layer is provided on an amorphous semiconductor layer prior to performing metal-induced crystallization of the semiconductor layer. The oxide or nitride layer facilitates conversion of the amorphous material into large grain polycrystalline material. Hence, a native silicon dioxide layer provided on hydrogenated amorphous silicon (a-Si:H), followed by deposited Al permits induced crystallization at temperatures far below the solid phase crystallization temperature of a-Si. Solar cells and thin film transistors can be prepared using this method.

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. Vertical silicon nanowire arrays for gas sensing

    E-Print Network [OSTI]

    Zhao, Hangbo

    2014-01-01T23:59:59.000Z

    The goal of this research was to fabricate and characterize vertically aligned silicon nanowire gas sensors. Silicon nanowires are very attractive for gas sensing applications and vertically aligned silicon nanowires are ...

  5. Core-Shell Nanopillar Array Solar Cells using Cadmium Sulfide Coating on Indium Phosphide Nanopillars

    E-Print Network [OSTI]

    Tu, Bor-An Clayton

    2013-01-01T23:59:59.000Z

    Monocrystalline silicon solar cells, polycrystalline silicon solar cells, and amorphous silicon (thin-film)

  6. Core-Shell Nanopillar Array Solar Cells using Cadmium Sulfide Coating on Indium Phosphide Nanopillars

    E-Print Network [OSTI]

    Tu, Bor-An Clayton

    2013-01-01T23:59:59.000Z

    Monocrystalline silicon solar cells, polycrystalline silicon solar cells, and amorphous silicon (thin-film) solar

  7. High Efficiency Thin Film CdTe and a-Si Based Solar Cells Final Technical Report for the Period

    E-Print Network [OSTI]

    Deng, Xunming

    High Efficiency Thin Film CdTe and a-Si Based Solar Cells Final Technical Report for the Period This is the final report covering approximately 42 months of this subcontract for research on high efficiency CdTe-based thin-film solar cells and on high efficiency a-Si-based thin-film solar cells. Phases I and II have

  8. Fabrication of porous silicon membranes

    E-Print Network [OSTI]

    Yue, Wing Kong

    1988-01-01T23:59:59.000Z

    efficiencies. The silicon difluoride, SiFq, is an unstable substance. It reacts with hydrofluoric acid forming silicic acid (HqSiFs) and hydrogen gas(Hq): SiFs + 2HF ? & SiF4+ Hs, (2) Si F4 + 2 H F ~ Hr Si Fs. In dilute HF solution, silicon can also react.... In step 1, the surface of silicon is covered with fluorine ions. In step 2, when an electric field is applied across the interface, holes move towards the surface. In step 3, some of the holes are trapped at the surface, and they weaken the silicon...

  9. UNIVERSITY OF CALIFORNIA, BERKELEY BERKELEY DAVIS IRVINE LOS ANGELES RIVERSIDE SAN DIEGO SAN FRANCISCO SANTA BARBARA SANTA CRUZ

    E-Print Network [OSTI]

    Kammen, Daniel M.

    indicates a need for measures to ensure the high quality of all modules sold in the Kenyan PV market. Kenya performance of single junction amorphous silicon (a-Si) photovoltaic (PV) modules in Kenya in 1999. The large majority of the a-Si PV modules sold in Kenya are made by three different manufacturers. Results from

  10. A thin film transistor driven microchannel device 

    E-Print Network [OSTI]

    Lee, Hyun Ho

    2005-02-17T23:59:59.000Z

    perturbation, an amorphous silicon (a-Si:H) thin film transistor (TFT) was connected to the microchannel device. The self-aligned a-Si:H TFT was fabricated with a two-photomask process. The result shows that the attachment of the TFT successfully suppressed...

  11. Stress-induced patterns in ion-irradiated Silicon: a model based on anisotropic plastic flow

    E-Print Network [OSTI]

    Scott A. Norris

    2012-07-24T23:59:59.000Z

    We present a model for the effect of stress on thin amorphous films that develop atop ion-irradiated silicon, based on the mechanism of ion-induced anisotropic plastic flow. Using only parameters directly measured or known to high accuracy, the model exhibits remarkably good agreement with the wavelengths of experimentally-observed patterns, and agrees qualitatively with limited data on ripple propagation speed. The predictions of the model are discussed in the context of other mechanisms recently theorized to explain the wavelengths, including extensive comparison with an alternate model of stress.

  12. Epitaxial ferromagnetic oxide thin films on silicon with atomically sharp interfaces

    SciTech Connect (OSTI)

    Coux, P. de [Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Barcelona (Spain); CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347, Toulouse Cedex 4 (France); Bachelet, R.; Fontcuberta, J.; Sánchez, F., E-mail: fsanchez@icmab.es [Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Barcelona (Spain); Warot-Fonrose, B. [CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347, Toulouse Cedex 4 (France); Skumryev, V. [Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain and Dep. de Física, Univ. Autònoma de Barcelona, 08193 Bellaterra (Spain); Lupina, L.; Niu, G.; Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)

    2014-07-07T23:59:59.000Z

    A bottleneck in the integration of functional oxides with silicon, either directly grown or using a buffer, is the usual formation of an amorphous interfacial layer. Here, we demonstrate that ferromagnetic CoFe{sub 2}O{sub 4} films can be grown epitaxially on Si(111) using a Y{sub 2}O{sub 3} buffer layer, and remarkably the Y{sub 2}O{sub 3}/Si(111) interface is stable and remains atomically sharp. CoFe{sub 2}O{sub 4} films present high crystal quality and high saturation magnetization.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. The electroluminescence mechanism of Er³? in different silicon oxide and silicon nitride environments

    SciTech Connect (OSTI)

    Rebohle, L., E-mail: l.rebohle@hzdr.de; Wutzler, R.; Braun, M.; Helm, M.; Skorupa, W. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden - Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany); Berencén, Y.; Ramírez, J. M.; Garrido, B. [Dept. Electrònica, Martí i Franquès 1, Universitat de Barcelona, 08028 Barcelona (Spain); Hiller, D. [IMTEK, Faculty of Engineering, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany)

    2014-09-28T23:59:59.000Z

    Rare earth doped metal-oxide-semiconductor (MOS) structures are of great interest for Si-based light emission. However, several physical limitations make it difficult to achieve the performance of light emitters based on compound semiconductors. To address this point, in this work the electroluminescence (EL) excitation and quenching mechanism of Er-implanted MOS structures with different designs of the dielectric stack are investigated. The devices usually consist of an injection layer made of SiO? and an Er-implanted layer made of SiO?, Si-rich SiO?, silicon nitride, or Si-rich silicon nitride. All structures implanted with Er show intense EL around 1540 nm with EL power efficiencies in the order of 2 × 10?³ (for SiO?:Er) or 2 × 10??(all other matrices) for lower current densities. The EL is excited by the impact of hot electrons with an excitation cross section in the range of 0.5–1.5 × 10?¹?cm?². Whereas the fraction of potentially excitable Er ions in SiO? can reach values up to 50%, five times lower values were observed for other matrices. The decrease of the EL decay time for devices with Si-rich SiO? or Si nitride compared to SiO? as host matrix implies an increase of the number of defects adding additional non-radiative de-excitation paths for Er³?. For all investigated devices, EL quenching cross sections in the 10?²? cm² range and charge-to-breakdown values in the range of 1–10 C cm?² were measured. For the present design with a SiO? acceleration layer, thickness reduction and the use of different host matrices did not improve the EL power efficiency or the operation lifetime, but strongly lowered the operation voltage needed to achieve intense EL.

  19. 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...

  20. Amorphous Alloy Membranes for High Temperature Hydrogen Separation

    SciTech Connect (OSTI)

    Coulter, K

    2013-09-30T23:59:59.000Z

    At the beginning of this project, thin film amorphous alloy membranes were considered a nascent but promising new technology for industrial-scale hydrogen gas separations from coal- derived syngas. This project used a combination of theoretical modeling, advanced physical vapor deposition fabricating, and laboratory and gasifier testing to develop amorphous alloy membranes that had the potential to meet Department of Energy (DOE) targets in the testing strategies outlined in the NETL Membrane Test Protocol. The project is complete with Southwest Research Institute® (SwRI®), Georgia Institute of Technology (GT), and Western Research Institute (WRI) having all operated independently and concurrently. GT studied the hydrogen transport properties of several amorphous alloys and found that ZrCu and ZrCuTi were the most promising candidates. GT also evaluated the hydrogen transport properties of V, Nb and Ta membranes coated with different transition-metal carbides (TMCs) (TM = Ti, Hf, Zr) catalytic layers by employing first-principles calculations together with statistical mechanics methods and determined that TiC was the most promising material to provide catalytic hydrogen dissociation. SwRI developed magnetron coating techniques to deposit a range of amorphous alloys onto both porous discs and tubular substrates. Unfortunately none of the amorphous alloys could be deposited without pinhole defects that undermined the selectivity of the membranes. WRI tested the thermal properties of the ZrCu and ZrNi alloys and found that under reducing environments the upper temperature limit of operation without recrystallization is ~250 °C. There were four publications generated from this project with two additional manuscripts in progress and six presentations were made at national and international technical conferences. The combination of the pinhole defects and the lack of high temperature stability make the theoretically identified most promising candidate amorphous alloys unsuitable for application as hydrogen separation membranes in coal fire systems.

  1. Amorphous Metallic Glass as New High Power and Energy Density Anodes For Lithium Ion Rechargeable Batteries

    E-Print Network [OSTI]

    Meng, Shirley Y.

    We have investigated the use of aluminum based amorphous metallic glass as the anode in lithium ion rechargeable batteries. Amorphous metallic glasses have no long-range ordered microstructure; the atoms are less closely ...

  2. HCI Adsorption and Ionization on Amorphous and Crystalline H2O...

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

    HCI Adsorption and Ionization on Amorphous and Crystalline H2O Films below 50 K. HCI Adsorption and Ionization on Amorphous and Crystalline H2O Films below 50 K. Abstract:...

  3. Chemical Bonding In Amorphous Si Coated-carbon Nanotube As Anodes...

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

    Bonding In Amorphous Si Coated-carbon Nanotube As Anodes For Li ion Batteries: A XANES Study. Chemical Bonding In Amorphous Si Coated-carbon Nanotube As Anodes For Li ion...

  4. Amorphization of nanocrystalline 3C-SiC irradiated with Si+ ions...

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

    interface and interior amorphization. Citation: Jiang W, H Wang, I Kim, Y Zhang, and WJ Weber.2010."Amorphization of nanocrystalline 3C-SiC irradiated with Si+ ions."Journal of...

  5. A silicon photomultiplier readout for time of flight neutron spectroscopy with {gamma}-ray detectors

    SciTech Connect (OSTI)

    Pietropaolo, A.; Gorini, G. [Dipartimento di Fisica ''G. Occhialini'' and CNISM, Universita Degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Festa, G.; Andreani, C.; De Pascale, M. P.; Reali, E. [Dipartimento di Fisica and Centro NAST, Universita degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133, Roma (Italy); Grazzi, F. [Istituto dei Sistemi Complessi-Consiglio Nazionale delle Ricerche, Via Madonna del Piano n.10, I-50019 Sesto Fiorentino, Firenze (Italy); Schooneveld, E. M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

    2009-09-15T23:59:59.000Z

    The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of {gamma}-detection based on the new device.

  6. Properties of electroless Ni-W-P amorphous alloys

    SciTech Connect (OSTI)

    Zhang Bangwei [Academia Sinica, Shenyang (China). International Centre of Materials Physics] [Academia Sinica, Shenyang (China). International Centre of Materials Physics; [Hunan Univ., Changsha (China). Dept. of Applied Physics; Hu Wangyu; Zhang Qinglong; Qu Xuanyuan [Hunan Univ., Changsha (China). Dept. of Applied Physics] [Hunan Univ., Changsha (China). Dept. of Applied Physics

    1996-08-01T23:59:59.000Z

    This paper describes work performed to determine some of the properties of the electroless Ni-W-P amorphous deposits. Phosphorus contents were varied up to 32 at.%, and the amorphous structure was found to be present at phosphorus contents above 5 at.%. Irrespective of P content, all the deposits exhibits excellent adhesion to metallic substrates. The addition of even small amounts of W provided greatly increased hardness compared with the plain Ni-P deposits. The wettability properties of the Ni-W-P deposits were found to be comparable to those of Ni-P and N-B-P deposits but inferior to those of Ni-B deposits.

  7. Mossbauer-effect and x-ray-absorption spectral study of sonochemically prepared amorphous iron

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    Received 10 November 1997 The Mo¨ssbauer spectra of amorphous iron, prepared by using sonochemical methods

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Mechanical Properties of Al-based Amorphous Alloy Ribbons Chun-Kuo Huang & John J. Lewandowski

    E-Print Network [OSTI]

    Rollins, Andrew M.

    for structural materials. Significant interest has arisen in amorphous aluminum alloys in recent years because MATERIALS FATIGUE DUCTILY TEST Amorphous aluminum alloys Al alloys Ti alloys Mg alloys Steels InhomogeneousMechanical Properties of Al-based Amorphous Alloy Ribbons Chun-Kuo Huang & John J. Lewandowski

  13. Phosphate and Organic Acids as Competing Sorbates on Amorphous Aluminum Oxide. (3791)

    E-Print Network [OSTI]

    Sparks, Donald L.

    Phosphate and Organic Acids as Competing Sorbates on Amorphous Aluminum Oxide. (3791) Authors: K sorption of P to amorphous aluminum oxides. Alum initially decreases litter pH, so the stability of P was employed to investigate the adsorption of phosphate and oxalate, to synthetic amorphous aluminum hydroxide

  14. Process for forming retrograde profiles in silicon

    DOE Patents [OSTI]

    Weiner, K.H.; Sigmon, T.W.

    1996-10-15T23:59:59.000Z

    A process is disclosed 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 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.

  15. 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.

  16. High specific activity silicon-32

    DOE Patents [OSTI]

    Phillips, D.R.; Brzezinski, M.A.

    1996-06-11T23:59:59.000Z

    A process for preparation of silicon-32 is provided and includes contacting an irradiated potassium chloride target, including spallation products from a prior irradiation, with sufficient water, hydrochloric acid or potassium hydroxide to form a solution, filtering the solution, adjusting pH of the solution from about 5.5 to about 7.5, admixing sufficient molybdate-reagent to the solution to adjust the pH of the solution to about 1.5 and to form a silicon-molybdate complex, contacting the solution including the silicon-molybdate complex with a dextran-based material, washing the dextran-based material to remove residual contaminants such as sodium-22, separating the silicon-molybdate complex from the dextran-based material as another solution, adding sufficient hydrochloric acid and hydrogen peroxide to the solution to prevent reformation of the silicon-molybdate complex and to yield an oxidation state of the molybdate adapted for subsequent separation by an anion exchange material, contacting the solution with an anion exchange material whereby the molybdate is retained by the anion exchange material and the silicon remains in solution, and optionally adding sufficient alkali metal hydroxide to adjust the pH of the solution to about 12 to 13. Additionally, a high specific activity silicon-32 product having a high purity is provided.

  17. High specific activity silicon-32

    DOE Patents [OSTI]

    Phillips, Dennis R. (Los Alamos, NM); Brzezinski, Mark A. (Santa Barbara, CA)

    1996-01-01T23:59:59.000Z

    A process for preparation of silicon-32 is provided and includes contacting an irradiated potassium chloride target, including spallation products from a prior irradiation, with sufficient water, hydrochloric acid or potassium hydroxide to form a solution, filtering the solution, adjusting pH of the solution to from about 5.5 to about 7.5, admixing sufficient molybdate-reagent to the solution to adjust the pH of the solution to about 1.5 and to form a silicon-molybdate complex, contacting the solution including the silicon-molybdate complex with a dextran-based material, washing the dextran-based material to remove residual contaminants such as sodium-22, separating the silicon-molybdate complex from the dextran-based material as another solution, adding sufficient hydrochloric acid and hydrogen peroxide to the solution to prevent reformation of the silicon-molybdate complex and to yield an oxidization state of the molybdate adapted for subsequent separation by an anion exchange material, contacting the solution with an anion exchange material whereby the molybdate is retained by the anion exchange material and the silicon remains in solution, and optionally adding sufficient alkali metal hydroxide to adjust the pH of the solution to about 12 to 13. Additionally, a high specific activity silicon-32 product having a high purity is provided.

  18. Critical Behavior of the Thermoelectric Transport Properties in Amorphous Systems

    E-Print Network [OSTI]

    Chemnitz, Technische Universität

    Critical Behavior of the Thermoelectric Transport Properties in Amorphous Systems near the Metal., London SW7 2BZ, U.K. Abstract The scaling behavior of the thermoelectric trans- port properties;, the thermoelectric power S, the thermal conductivity K and the Lorenz number L0 obey scaling. The scaling description

  19. amorphous peroxotitanate materials: Topics by E-print Network

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

    amorphous peroxotitanate materials First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Two-dimensional...

  20. amorphous rare earth: Topics by E-print Network

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

    amorphous rare earth First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Acoustic propagation at low...

  1. amorphous carbon thin: Topics by E-print Network

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

    amorphous carbon thin First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Poster Oral Room ROOM Temperature...

  2. amorphous carbon blacks: Topics by E-print Network

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

    carbon blacks First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 RESEARCH PAPER Amorphous dysprosium...

  3. Reversible plasticity in amorphous materials Micah Lundberg1

    E-Print Network [OSTI]

    Dennin, Michael

    Reversible plasticity in amorphous materials Micah Lundberg1 , Kapilanjan Krishan1 , Ning Xu2 to external loads. Plasticity, i.e. dis- sipative and irreversible macroscopic changes in a material for reversible plastic events at the microscopic scale in both experiments and simulations of two

  4. 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...

  5. Electrochemical characteristics of plasma-etched black silicon as anodes for Li-ion batteries

    SciTech Connect (OSTI)

    Lee, Gibaek; Wehrspohn, Ralf B., E-mail: ralf.b.wehrspohn@iwmh.fraunhofer.de [Fraunhofer Institute for Mechanics of Materials IWM, Halle (Saale) 06120, Germany and Department of Physics, Martin-Luther University, Halle (Saale) 06099 (Germany); Schweizer, Stefan L. [Department of Physics, Martin-Luther University, Halle (Saale) 06099 (Germany)

    2014-11-01T23:59:59.000Z

    Nanostructured silicon as an anode material for Li-ion batteries is produced for the first time by inductively coupled plasma–plasma etching of Si wafers in the black silicon regime. The microscopic structure strongly resembles other types of nanostructured silicon, with a well-arranged nanostructure possessing a sufficient porosity for accommodating large volume expansion. Despite these features, however, a high first-cycle irreversible capacity loss and a poor cycle life are observed. The main reason for these poor features is the formation of a thick solid-electrolyte interphase (SEI) layer related to the surface condition of the pristine nanostructured black silicon (b-Si) electrode. Therefore, the cycle life of the b-Si electrode is heavily influenced by the constant reformation of the SEI layer depending upon the surface composition in spite of the presence of nanostructured Si. In the fast lithiation experiments, the nanostructure region of the b-Si electrode is detached from the Si substrate owing to the kinetics difference between the lithium ion diffusion and the electron injection and phase transformation in the nanostructured Si region. This means that more Si substrate is involved in lithiation at high current rates. It is therefore important to maintain balance in the chemical kinetics during the lithiation of nanostructured Si electrodes with a Si substrate.

  6. Amorphous metal formulations and structured coatings for corrosion and wear resistance

    DOE Patents [OSTI]

    Farmer, Joseph C. (Tracy, CA)

    2011-12-13T23:59:59.000Z

    A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

  7. Amorphous metal formulations and structured coatings for corrosion and wear resistance

    DOE Patents [OSTI]

    Farmer, Joseph C.

    2014-07-15T23:59:59.000Z

    A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

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

    E-Print Network [OSTI]

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

    2010-11-13T23:59:59.000Z

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

  9. Arnold Schwarzenegger SINGLE CRYSTAL SILICON

    E-Print Network [OSTI]

    in this report. #12;ENERGY INNOVATIONS SMALL GRANT (EISG) PROGRAM INDEPENDENT ASSESSMENT REPORT (IAR) SINGLEArnold Schwarzenegger Governor SINGLE CRYSTAL SILICON SHEET GROWTH Prepared For: California Energy Commission Energy Innovations Small Grant Program Prepared By: Energy Materials Research

  10. Polarization manipulation in silicon photonics

    E-Print Network [OSTI]

    Su, Zhan, S.M. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Silicon photonics is moving fast toward industrialization. It satisfies the increasing demand for higher speed, larger bandwidth communication. Thus it has a wide range of applications including high-performance computing, ...

  11. Correlation of atomic packing with the boson peak in amorphous alloys

    SciTech Connect (OSTI)

    Yang, W. M. [State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, School of Sciences, China University of Mining and Technology, Xuzhou 221116 (China); Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); Liu, H. S., E-mail: liuhaishun@126.com, E-mail: blshen@seu.edu.cn, E-mail: runweili@nimte.ac.cn, E-mail: jiangjz@zju.edu.cn; Zhao, Y. C. [State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, School of Sciences, China University of Mining and Technology, Xuzhou 221116 (China); Liu, X. J. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Chen, G. X.; Man, Q. K.; Chang, C. T.; Li, R. W., E-mail: liuhaishun@126.com, E-mail: blshen@seu.edu.cn, E-mail: runweili@nimte.ac.cn, E-mail: jiangjz@zju.edu.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Dun, C. C. [Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109 (United States); Shen, B. L., E-mail: liuhaishun@126.com, E-mail: blshen@seu.edu.cn, E-mail: runweili@nimte.ac.cn, E-mail: jiangjz@zju.edu.cn [School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); Inoue, A. [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); and others

    2014-09-28T23:59:59.000Z

    Boson peaks (BP) have been observed from phonon specific heats in 10 studied amorphous alloys. Two Einstein-type vibration modes were proposed in this work and all data can be fitted well. By measuring and analyzing local atomic structures of studied amorphous alloys and 56 reported amorphous alloys, it is found that (a) the BP originates from local harmonic vibration modes associated with the lengths of short-range order (SRO) and medium-range order (MRO) in amorphous alloys, and (b) the atomic packing in amorphous alloys follows a universal scaling law, i.e., the ratios of SRO and MRO lengths to solvent atomic diameter are 3 and 7, respectively, which exact match with length ratios of BP vibration frequencies to Debye frequency for the studied amorphous alloys. This finding provides a new perspective for atomic packing in amorphous materials, and has significant implications for quantitative description of the local atomic orders and understanding the structure-property relationship.

  12. Microstructure of amorphous indium oxide and tin oxide thin films

    SciTech Connect (OSTI)

    Rauf, I.A.; Brown, L.M. (Univ. of Cambridge (United Kingdom))

    1994-03-15T23:59:59.000Z

    Indium oxide, tin oxide, and some other doped and undoped oxide semiconductors show an interesting and technologically important combination of properties. They have high luminous transparency, good electrical conductivity and high infrared reflectivity. Numerous techniques for depositing these materials have been developed and have undergone a number of changes during last two decades. An understanding of the basic physics of these materials has begun to dawn. Most of the literature on transparent conducting oxides consists of studying the dependence of the properties on the composition, preparation conditions, such as deposition rate, substrate temperature or post-deposition heat treatment. In this paper the authors have employed the transmission electron microscopy to study the microstructure of reactively evaporated, electron beam evaporated, ion-beam sputtered amorphous indium oxide and reactively evaporated amorphous tin oxide thin films. These films, which have received little attention in the past, can have enormous potential as transparent conductive coatings on heat-sensitive substrates and inexpensive solar cells.

  13. The Anatomy of Plastic Events in Magnetic Amorphous Solids

    E-Print Network [OSTI]

    H. George E. Hentschel; Itamar Procaccia; Bhaskar Sen Gupta

    2015-01-25T23:59:59.000Z

    Plastic events in amorphous solids can be much more than just "shear transformation zones" when the positional degrees of freedom are coupled non-trivially to other degrees of freedom. Here we consider magnetic amorphous solids where mechanical and magnetic degrees of freedom interact, leading to rather complex plastic events whose nature must be disentangled. In this paper we uncover the anatomy of the various contributions to some typical plastic events. These plastic events are seen as Barkhausen Noise or other "serrated noises". Using theoretical considerations we explain the observed statistics of the various contributions to the considered plastic events. The richness of contributions and their different characteristics imply that in general the statistics of these "serrated noises" cannot be universal, but rather highly dependent on the state of the system and on its microscopic interactions.

  14. Amorphous tin-cadmium oxide films and the production thereof

    DOE Patents [OSTI]

    Li, Xiaonan; Gessert, Timothy A

    2013-10-29T23:59:59.000Z

    A tin-cadmium oxide film having an amorphous structure and a ratio of tin atoms to cadmium atoms of between 1:1 and 3:1. The tin-cadmium oxide film may have an optical band gap of between 2.7 eV and 3.35 eV. The film may also have a charge carrier concentration of between 1.times.10.sup.20 cm.sup.-3 and 2.times.10.sup.20 cm.sup.-3. The tin cadmium oxide film may also exhibit a Hall mobility of between 40 cm.sup.2V.sup.-1 s.sup.-1 and 60 cm.sup.2V.sup.-1 s.sup.-1. Also disclosed is a method of producing an amorphous tin-cadmium oxide film as described and devices using same.

  15. Absorption of ac fields in amorphous indium-oxide films

    SciTech Connect (OSTI)

    Ovadyahu, Z. [Racah Institute of Physics, the Hebrew University, Jerusalem 91904 (Israel)

    2014-08-20T23:59:59.000Z

    Absorption data from applied ac fields in Anderson-localized amorphous indium-oxide (In{sub x}O) films are shown to be frequency and disorder dependent. The absorption shows a roll-off at a frequency which is much lower than the electron-electron scattering rate of the material when it is in the diffusive regime. This is interpreted as evidence for discreteness of the energy spectrum of the deeply localized regime. This is consistent with recent many-body localization scenarios. As the metal-insulator transition is approached, the absorption shifts to higher frequencies. Comparing with the previously obtained results on the crystalline version of indium-oxide (In{sub 2}O{sub 3?x}) implies a considerably higher inelastic electron-phonon scattering rate in the amorphous material. The range over which the absorption versus frequency decreases may indicate that a wide distribution of localization length is a common feature in these systems.

  16. Fabrication of a single layer graphene by copper intercalation on a SiC(0001) surface

    SciTech Connect (OSTI)

    Yagyu, Kazuma; Tochihara, Hiroshi; Tomokage, Hajime; Suzuki, Takayuki [Department of Electronics Engineering and Computer Science, Fukuoka University, Fukuoka 814-0180 (Japan); Tajiri, Takayuki; Kohno, Atsushi [Department of Applied Physics, Fukuoka University, Fukuoka 814-0180 (Japan); Takahashi, Kazutoshi [Synchrotron Light Application Center, Saga University, 1 Honjo, Saga 840-8502 (Japan)

    2014-02-03T23:59:59.000Z

    Cu atoms deposited on a zero layer graphene grown on a SiC(0001) substrate, intercalate between the zero layer graphene and the SiC substrate after the thermal annealing above 600?°C, forming a Cu-intercalated single layer graphene. On the Cu-intercalated single layer graphene, a graphene lattice with superstructure due to moiré pattern is observed by scanning tunneling microscopy, and specific linear dispersion at the K{sup ¯} point as well as a characteristic peak in a C{sub 1s} core level spectrum, which is originated from a free-standing graphene, is confirmed by photoemission spectroscopy. The Cu-intercalated single layer graphene is found to be n-doped.

  17. Observation of the photodielectric effect in an amorphous semiconductor

    E-Print Network [OSTI]

    Collins, Stephen Anthony

    1971-01-01T23:59:59.000Z

    OBSERVATION OF THE PHOTODIELECTRIC EFFECT IN AN AHGRPBGUS SFNICONDUCTOR A THESIS by STEPHEN ANTHONY COLLINS Subqitted tu the Graduate College of Texas A&M University iu Partial fulfillment of. the requirement for the. degree of 1IASTER OI...' SCIFNCE August 1971 Hajcr Suhjec '. Fleqtricel magic. earing OBSERVATION OF THE PHOTODIELECTRIC EFFECT IN AN AMORPHOUS SEMICONDUCTOR A THESIS by STEPHEN ANTHONY COLLINS Approved as to style and content by: (Chairman of Committee) (Head of epartm...

  18. Formation of amorphous metal alloys by chemical vapor deposition

    DOE Patents [OSTI]

    Mullendore, A.W.

    1988-03-18T23:59:59.000Z

    Amorphous alloys are deposited by a process of thermal dissociation of mixtures of organometallic compounds and metalloid hydrides,e.g., transition metal carbonyl, such as nickel carbonyl and diborane. Various sizes and shapes of deposits can be achieved, including near-net-shape free standing articles, multilayer deposits, and the like. Manipulation or absence of a magnetic field affects the nature and the structure of the deposit. 1 fig.

  19. Electrodeposition of amorphous ternary nickel-chromium-phosphorus alloy

    DOE Patents [OSTI]

    Guilinger, Terry R. (Albuquerque, NM)

    1990-01-01T23:59:59.000Z

    Amorphous ternary nickel-chromium-phosphorus alloys are electrodeposited from a bath comprising a nickel salt, a chromium salt, a phosphorus source such as sodium hypophosphite, a complexing agent for the nickel ions, supporting salts to increase conductivity, and a buffering agent. The process is carried out at about room temperature and requires a current density between about 20 to 40 A/dm.sup.2.

  20. Formation of amorphous metal alloys by chemical vapor deposition

    DOE Patents [OSTI]

    Mullendore, Arthur W. (Sandia Park, NM)

    1990-01-01T23:59:59.000Z

    Amorphous alloys are deposited by a process of thermal dissociation of mixtures or organometallic compounds and metalloid hydrides, e.g., transition metal carbonyl such as nickel carbonyl, and diborane. Various sizes and shapes of deposits can be achieved, including near-net-shape free standing articles, multilayer deposits, and the like. Manipulation or absence of a magnetic field affects the nature and the structure of the deposit.

  1. Intel Corporation CREOL April 1 2005 SiliconSilicon PhotonicsPhotonics

    E-Print Network [OSTI]

    Van Stryland, Eric

    Recent resultsRecent results ­­IntelIntel''s Silicon Lasers Silicon Laser SummarySummary #12;*Third party of their respective ownerve owner 44 Industry standard silicon manufacturing processes couldIndustry standard silicon manufacturing processes could enable integration, bring volume economics to optical.enable integration, bring

  2. ENERGY & ENVIRONMENT DIVISION ANNUAL REPORT 1979

    E-Print Network [OSTI]

    Cairns, E.J.

    2010-01-01T23:59:59.000Z

    photovoltaic appli- cations and their unique properties as amorphous materials. The amorphous silicon hydrogen

  3. Design of a silicon waver breaker

    E-Print Network [OSTI]

    Mukaddam, Kabir James, 1983-

    2005-01-01T23:59:59.000Z

    Usually multiple MEMS or IC devices are fabricated on a single silicon wafer. Manually separating the components from each other involves scribing and fracturing the silicon. This thesis presents a design for a tool to aid ...

  4. 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 ...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. Birefringence Measurements on Crystalline Silicon

    E-Print Network [OSTI]

    Krüger, Christoph; Khalaidovski, Alexander; Steinlechner, Jessica; Nawrodt, Ronny; Schnabel, Roman; Lück, Harald

    2015-01-01T23:59:59.000Z

    Crystalline silicon has been proposed as a new test mass material in third generation gravitational wave detectors such as the Einstein Telescope (ET). Birefringence can reduce the interferometric contrast and can produce dynamical disturbances in interferometers. In this work we use the method of polarisation-dependent resonance frequency analysis of Fabry-Perot-cavities containing silicon as a birefringent medium. Our measurements show a birefringence of silicon along the (111) axis of the order of $\\Delta\\, n \\approx 10^{-7}$ at a laser wavelength of 1550nm and room temperature. A model is presented that explains the results of different settings of our measurements as a superposition of elastic strains caused by external stresses in the sample and plastic strains possibly generated during the production process. An application of our theory on the proposed ET test mass geometry suggests no critical effect on birefringence due to elastic strains.

  11. 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.

  12. 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.

  13. Characterization of the Electronic Structure of Silicon Nanoparticles Using X-ray Absorption and Emission

    SciTech Connect (OSTI)

    Vaverka, A M

    2008-07-15T23:59:59.000Z

    Resolving open questions regarding transport in nanostructures can have a huge impact on a broad range of future technologies such as light harvesting for energy. Silicon has potential to be used in many of these applications. Understanding how the band edges of nanostructures move as a function of size, surface termination and assembly is of fundamental importance in understanding the transport properties of these materials. In this thesis work I have investigated the change in the electronic structure of silicon nanoparticle assemblies as the surface termination is changed. Nanoparticles are synthesized using a thermal evaporation technique and sizes are determined using atomic force microscopy (AFM). By passivating the particles with molecules containing alcohol groups we are able to modify the size dependent band edge shifts. Both the valence and conduction bands are measured using synchrotron based x-ray absorption spectroscopy (XAS) and soft x-ray fluorescence (SXF) techniques. Particles synthesized via recrystallization of amorphous silicon/SiO{sub 2} multilayers of thicknesses below 10 nm are also investigated using the synchrotron techniques. These samples also show quantum confinement effects but the electronic structure is different from those synthesized via evaporation methods. The total bandgap is determined for all samples measured. The origins of these differences in the electronic structures are discussed.

  14. 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.

  15. 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.

  16. 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.

  17. The Structure and Properties of Amorphous Indium Oxide D. Bruce Buchholz,

    E-Print Network [OSTI]

    Medvedeva, Julia E.

    on amorphous silica substrates using pulsed laser deposition by varying the film growth temperature structure for TCOs and TOSs is a network of MOx polyhedra. Each metal ion

  18. amorphous carbon-nitride films: Topics by E-print Network

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

    in hard and elastic amorphous carbon nitride films investigated H NMR spectroscopy Materials Science Websites Summary: Received 14 February 2003; published 5 November 2003 The...

  19. E-Print Network 3.0 - amorphous selenium flat Sample Search Results

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

    on a-Se direct conversion detector Summary: ). The digital detector consists of a flat panel using the amorphous selenium technology (ANRAD Corporation... : the most promising are...

  20. E-Print Network 3.0 - amorphous fe-b particles Sample Search...

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

    Summary: -rich particles in an amorphous matrix that presumably consists of melted aerogel. An HRTEM lattice image of one... -C nanoparticles (Cabot, unpublished data; van...

  1. Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material

    DOE Patents [OSTI]

    Sopori, Bhushan; Rangappan, Anikara

    2014-11-25T23:59:59.000Z

    Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

  2. Impact of growth conditions on vacancy-type defects in silicon-germanium structures grown by molecular-beam epitaxy

    SciTech Connect (OSTI)

    Shoukri, Kareem M.; Haddara, Yaser M.; Knights, A.P.; Coleman, P.G. [Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

    2005-03-28T23:59:59.000Z

    Silicon-germanium layers of either 200 nm or 250 nm have been grown via molecular-beam epitaxy (MBE) on p-type (001) silicon substrates. Each sample was prepared using a unique combination of buffer-layer type, buffer-layer growth temperature, and layer Ge content. Vacancy-type defects have been identified using beam-based positron annihilation. These results, combined with those from previous work, indicate the size and concentration of defects in MBE grown SiGe layers depend strongly upon the buffer-layer growth temperature (T). For T>500 deg. C vacancy point defect concentrations are below the detectable limit of the measurement. As T is decreased to 300 deg. C, vacancy clusters form in the buffer layer and point defects appear in the SiGe film, even for a SiGe growth temperature of 500 deg. C.

  3. Control of morphology for enhanced electronic transport in PECVD-grown a-Si : H Thin Films

    E-Print Network [OSTI]

    Castro Galnares, Sebastián

    2010-01-01T23:59:59.000Z

    Solar cells have become an increasingly viable alternative to traditional, pollution causing power generation methods. Although crystalline silicon (c-Si) modules make up most of the market, thin films such as hydrogenated ...

  4. BORON CONCENTRATION MEASUREMENTS AT THE I/P INTERFACE IN NIP A-SI SOLAR CELLS B.B. Van Aken1

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    BORON CONCENTRATION MEASUREMENTS AT THE I/P INTERFACE IN NIP A-SI SOLAR CELLS B.B. Van Aken1 , M-type Si layer in n-i-p a-Si and c-Si solar cells on foil has several important requirements with respect-i-p solar cells is obtained when the p-a-SiC band gap is just above the band gap of the absorber layer. We

  5. Direct measurement of the reactivity of NH and OH on a silicon nitride surface

    SciTech Connect (OSTI)

    Buss, R.J.; Ho, P.; Breiland, W.G. [Sandia National Labs., Albuquerque, NM (United States); Fisher, E.R. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry

    1993-12-31T23:59:59.000Z

    In order to understand and successfully model the plasma processing used in device fabrication, it is important to determine the role played by plasma-generated radicals. The authors have used the IRIS technique (Imaging of Radicals Interacting Surfaces) to obtain the reactivity of NH (X{sup 3}S{sup {minus}}) and OH (X{sup 2}P) at a silicon nitride film surface while the film is exposed to a plasma-type environment. The reactivity of NH was found to be zero both during exposure of the surface to an NH{sub 3} plasma and during active deposition of silicon nitride from a SiH{sub 4}/NH{sub 3} plasma. No NH surface reaction was detectable for any rotational states of NH and over a surface temperature range of 300--700 K. OH radicals generated in an H{sub 2}O plasma were found to have a reactivity of 0.57 on a room temperature oxidized silicon nitride surface. The OH reactivity falls to zero as the temperature of the substrate is raised.

  6. Electrostatically defined Quantum Dots in a Si/SiGe Heterostructure

    E-Print Network [OSTI]

    A. Wild; J. Sailer; J. Nützel; G. Abstreiter; S. Ludwig; D. Bougeard

    2010-07-14T23:59:59.000Z

    We present an electrostatically defined few-electron double quantum dot (QD) realized in a molecular beam epitaxy grown Si/SiGe heterostructure. Transport and charge spectroscopy with an additional QD as well as pulsed-gate measurements are demonstrated. We discuss technological challenges specific for silicon-based heterostructures and the effect of a comparably large effective electron mass on transport properties and tunability of the double QD. Charge noise, which might be intrinsically induced due to strain-engineering is proven not to affect the stable operation of our device as a spin qubit. Our results promise the suitability of electrostatically defined QDs in Si/SiGe heterostructures for quantum information processing.

  7. Electrostatically defined Quantum Dots in a Si/SiGe Heterostructure

    E-Print Network [OSTI]

    Wild, A; Nützel, J; Abstreiter, G; Ludwig, S; Bougeard, D

    2010-01-01T23:59:59.000Z

    We present an electrostatically defined few-electron double quantum dot (QD) realized in a molecular beam epitaxy grown Si/SiGe heterostructure. Transport and charge spectroscopy with an additional QD as well as pulsed-gate measurements are demonstrated. We discuss technological challenges specific for silicon-based heterostructures and the effect of a comparably large effective electron mass on transport properties and tunability of the double QD. Charge noise, which might be intrinsically induced due to strain-engineering is proven not to affect the stable operation of our device as a spin qubit. Our results promise the suitability of electrostatically defined QDs in Si/SiGe heterostructures for quantum information processing.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. MODELING OF TRIPLE JUNCTION A-SI SOLAR CELLS USING ASA: ANALYSIS OF DEVICE PERFORMANCE UNDER VARIOUS FAILURE SCENARIOS

    E-Print Network [OSTI]

    Deng, Xunming

    have experienced a significant increase in the recent years. Solar panels with triple- junction found. To assist the optimization of solar cell fabrication and cost-effective industrial photovoltaicMODELING OF TRIPLE JUNCTION A-SI SOLAR CELLS USING ASA: ANALYSIS OF DEVICE PERFORMANCE UNDER

  13. Particle-induced amorphization of complex ceramics. Final report

    SciTech Connect (OSTI)

    Ewing, R.C.; Wang, L.M.

    1998-08-01T23:59:59.000Z

    The crystalline-to-amorphous (c-a) phase transition is of fundamental importance. Particle irradiations provide an important, highly controlled means of investigating this phase transformation and the structure of the amorphous state. The interaction of heavy-particles with ceramics is complex because these materials have a wide range of structure types, complex compositions, and because chemical bonding is variable. Radiation damage and annealing can produce diverse results, but most commonly, single crystals become aperiodic or break down into a polycrystalline aggregate. The authors continued the studies of the transition from the periodic-to-aperiodic state in natural materials that have been damaged by {alpha}-recoil nuclei in the uranium and thorium decay series and in synthetic, analogous structures. The transition from the periodic to aperiodic state was followed by detailed x-ray diffraction analysis, in-situ irradiation/transmission electron microscopy, high resolution transmission electron microscopy, extended x-ray absorption fine structure spectroscopy/x-ray absorption near edge spectroscopy and other spectroscopic techniques. These studies were completed in conjunction with bulk irradiations that can be completed at Los Alamos National Laboratory or Sandia National Laboratories. Principal questions addressed in this research program included: (1) What is the process at the atomic level by which a ceramic material is transformed into a disordered or aperiodic state? (2) What are the controlling effects of structural topology, bond-type, dose rate, and irradiation temperature on the final state of the irradiated material? (3) What is the structure of the damaged material? (4) What are the mechanisms and kinetics for the annealing of interstitial and aggregate defects in these irradiated ceramic materials? (5) What general criteria may be applied to the prediction of amorphization in complex ceramics?

  14. Sputter deposition of lithium silicate - lithium phosphate amorphous electrolytes

    SciTech Connect (OSTI)

    Dudney, N.J.; Bates, J.B.; Luck, C.F. (Oak Ridge National Lab., TN (USA)); Robertson, J.D. (Kentucky Univ., Lexington, KY (USA). Dept. of Chemistry)

    1991-01-01T23:59:59.000Z

    Thin films of an amorphous lithium-conducting electrolyte were deposited by rf magnetron sputtering of ceramic targets containing Li{sub 4}SiO{sub 4} and Li{sub 3}PO{sub 4}. The lithium content of the films was found to depend more strongly on the nature and composition of the targets than on many other sputtering parameters. For targets containing Li{sub 4}SiO{sub 4}, most of the lithium was found to segregate away from the sputtered area of the target. Codeposition using two sputter sources achieves a high lithium content in a controlled and reproducible film growth. 10 refs., 4 figs.

  15. Heat Transfer between Graphene and Amorphous SiO2

    E-Print Network [OSTI]

    B. N. J. Persson; H. Ueba

    2010-07-22T23:59:59.000Z

    We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.

  16. Electrodeposition of amorphous ternary nickel-chromium-phosphorus alloy

    SciTech Connect (OSTI)

    Guilinger, T.R.

    1990-01-09T23:59:59.000Z

    This patent describes a method of forming amorphous ternary nickel-phosphorus-chromium alloy deposits by electrodeposition on an electrically conductive substrate. It comprises: subjecting the substrate to an applied current density between about 20 and 40 A/dm{sup 2} at a temperature from the range of about 20{degrees} to 30{degrees} C. in a bath comprising: a chromium salt and a nickel salt in a weight ratio of about 3:1, a phosphorus source of about 0.3 M P concentration; about 0.3 M of a complexing agent; about 0.1 M of a supporting salt; and about 0.1 M of buffer.

  17. amorphous selenium flat-panel: Topics by E-print Network

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

    and organic Heikenfeld, Jason 12 Asymmetric electrical properties of fork a-Si:H thin-film transistor and its application to flat panel displays Mathematics Websites Summary:...

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

    E-Print Network [OSTI]

    Zeng, Li

    2007-01-01T23:59:59.000Z

    various transition or rare-earth metals provide a rich ?eldTransition Metal (Mn) and Rare Earth (Gd) Doped AmorphousTransition Metal (Mn) and Rare Earth (Gd) Doped Amorphous

  19. Black Ge Based on Crystalline/Amorphous Core/Shell Nanoneedle Arrays

    E-Print Network [OSTI]

    Javey, Ali

    Black Ge Based on Crystalline/Amorphous Core/Shell Nanoneedle Arrays Yu-Lun Chueh,,§,|,# Zhiyong, ROC ABSTRACT Direct growth of black Ge on low-temperature substrates, including plastics and rubber is reported. The material is based on highly dense, crystalline/amorphous core/shell Ge nanoneedle arrays

  20. AvAilAble for licensing A process for amorphous pharmaceuticals

    E-Print Network [OSTI]

    Kemner, Ken

    amorphous solids and molecular gels that can be easily applied to the pharmaceutical manufacturing process for additional details. Benefits A containerless process: Precludes the possibility of a drug's interaction during the manufacturing process; and Is expected to advance the development of amorphous drug forms

  1. Stress-corrosion fatiguecrack growth in a Zr-based bulk amorphous metal

    E-Print Network [OSTI]

    Ritchie, Robert

    Stress-corrosion fatigue­crack growth in a Zr-based bulk amorphous metal V. Schroeder 1 , R metallic glass; Amorphous metal; Fatigue; Stress corrosion; Crack growth 1. Introduction In recent years­crack growth resistance [1­5], its corresponding properties in the presence of a corrosive environment have

  2. Upconversion emission from amorphous Y2O3:Tm3+ prepared by

    E-Print Network [OSTI]

    Cao, Wenwu

    Upconversion emission from amorphous Y2O3:Tm3+ , Yb3+ prepared by nanosecond pulsed laser that the material produced by laser irradiation is amorphous, which presents strong blue upcon- version emission under the excitation of 976 nm diode laser. The relative intensity of the blue emission to the infrared

  3. The evaporation rate, free energy, and entropy of amorphous water Robin J. Speedy

    E-Print Network [OSTI]

    The evaporation rate, free energy, and entropy of amorphous water at 150 K Robin J. Speedy can be interpreted as giving a measure of their free energy difference, i a G 150 K 1100 100 J of amorphous water (a) and ice (i) near 150 K and suppose that their ratio gives a measure of their free energy

  4. Dynamics of viscoplastic deformation in amorphous solids M. L. Falk and J. S. Langer

    E-Print Network [OSTI]

    Weeks, Eric R.

    Dynamics of viscoplastic deformation in amorphous solids M. L. Falk and J. S. Langer Department 1997 We propose a dynamical theory of low-temperature shear deformation in amorphous solids. Our analysis is based on molecular-dynamics simulations of a two-dimensional, two-component noncrystalline

  5. Macromolecules 1996,28, 5819-5826 6819 Microscopic Theory of Chain Pullout in Amorphous Polymers

    E-Print Network [OSTI]

    Taylor, Philip L.

    Macromolecules 1996,28, 5819-5826 6819 Microscopic Theory of Chain Pullout in Amorphous Polymers T: The statistical-mechanical problem of chain pullout from an amorphous polymer under the influence of a constant in both polymer glasses and elastomeric materials from a single point of view. A mean-field approximation

  6. Large-scale molecular dynamics simulation of magnetic properties of amorphous iron under pressure

    E-Print Network [OSTI]

    ) Enhanced refrigerant capacity and magnetic entropy flattening using a two-amorphous FeZrB(Cu) compositeLarge-scale molecular dynamics simulation of magnetic properties of amorphous iron under pressure Appl. Phys. Lett. 99, 232501 (2011) Nonlinear motion of magnetic vortex under alternating

  7. Atomic hydrogen interactions with amorphous carbon thin films Bhavin N. Jariwala,1

    E-Print Network [OSTI]

    Ciobanu, Cristian

    Atomic hydrogen interactions with amorphous carbon thin films Bhavin N. Jariwala,1 Cristian V-scale interactions of H atoms with hydrogenated amorphous carbon a-C:H films were identified using molecular dynamics through a detailed analysis of the MD trajectories. The MD simulations showed that hydrogenation occurs

  8. Surface tension of amorphous polymer lms Thorsten Hapke, Gerald Patzold, and Dieter W. Heermann

    E-Print Network [OSTI]

    Heermann, Dieter W.

    Surface tension of amorphous polymer lms Thorsten Hapke, Gerald Patzold, and Dieter W. Heermann study the surface tension for thin, amorphous polymer lms by means of computer simulation. In the framework of molecular dynamics, we present surface tension measurements via the uctuation spectrum

  9. Developing a High Thermal Conductivity Fuel with Silicon Carbide Additives

    SciTech Connect (OSTI)

    baney, Ronald; Tulenko, James

    2012-11-20T23:59:59.000Z

    The objective of this research is to increase the thermal conductivity of uranium oxide (UO{sub 2}) without significantly impacting its neutronic properties. The concept is to incorporate another high thermal conductivity material, silicon carbide (SiC), in the form of whiskers or from nanoparticles of SiC and a SiC polymeric precursor into UO{sub 2}. This is expected to form a percolation pathway lattice for conductive heat transfer out of the fuel pellet. The thermal conductivity of SiC would control the overall fuel pellet thermal conductivity. The challenge is to show the effectiveness of a low temperature sintering process, because of a UO{sub 2}-SiC reaction at 1,377°C, a temperature far below the normal sintering temperature. Researchers will study three strategies to overcome the processing difficulties associated with pore clogging and the chemical reaction of SiC and UO{sub 2} at temperatures above 1,300°C:

  10. A nonlinear lag correction algorithm for a-Si flat-panel x-ray detectors

    SciTech Connect (OSTI)

    Starman, Jared; Star-Lack, Josh; Virshup, Gary; Shapiro, Edward; Fahrig, Rebecca [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States) and Department of Radiology, Stanford University, Stanford, California 94305 (United States); Varian Medical Systems, Palo Alto, California 94304 (United States); Department of Radiology, Stanfod University, Stanford, California 94305 (United States)

    2012-10-15T23:59:59.000Z

    Purpose: Detector lag, or residual signal, in a-Si flat-panel (FP) detectors can cause significant shading artifacts in cone-beam computed tomography reconstructions. To date, most correction models have assumed a linear, time-invariant (LTI) model and correct lag by deconvolution with an impulse response function (IRF). However, the lag correction is sensitive to both the exposure intensity and the technique used for determining the IRF. Even when the LTI correction that produces the minimum error is found, residual artifact remains. A new non-LTI method was developed to take into account the IRF measurement technique and exposure dependencies. Methods: First, a multiexponential (N = 4) LTI model was implemented for lag correction. Next, a non-LTI lag correction, known as the nonlinear consistent stored charge (NLCSC) method, was developed based on the LTI multiexponential method. It differs from other nonlinear lag correction algorithms in that it maintains a consistent estimate of the amount of charge stored in the FP and it does not require intimate knowledge of the semiconductor parameters specific to the FP. For the NLCSC method, all coefficients of the IRF are functions of exposure intensity. Another nonlinear lag correction method that only used an intensity weighting of the IRF was also compared. The correction algorithms were applied to step-response projection data and CT acquisitions of a large pelvic phantom and an acrylic head phantom. The authors collected rising and falling edge step-response data on a Varian 4030CB a-Si FP detector operating in dynamic gain mode at 15 fps at nine incident exposures (2.0%-92% of the detector saturation exposure). For projection data, 1st and 50th frame lag were measured before and after correction. For the CT reconstructions, five pairs of ROIs were defined and the maximum and mean signal differences within a pair were calculated for the different exposures and step-response edge techniques. Results: The LTI corrections left residual 1st and 50th frame lag up to 1.4% and 0.48%, while the NLCSC lag correction reduced 1st and 50th frame residual lags to less than 0.29% and 0.0052%. For CT reconstructions, the NLCSC lag correction gave an average error of 11 HU for the pelvic phantom and 3 HU for the head phantom, compared to 14-19 HU and 2-11 HU for the LTI corrections and 15 HU and 9 HU for the intensity weighted non-LTI algorithm. The maximum ROI error was always smallest for the NLCSC correction. The NLCSC correction was also superior to the intensity weighting algorithm. Conclusions: The NLCSC lag algorithm corrected for the exposure dependence of lag, provided superior image improvement for the pelvic phantom reconstruction, and gave similar results to the best case LTI results for the head phantom. The blurred ring artifact that is left over in the LTI corrections was better removed by the NLCSC correction in all cases.

  11. Plastic Deformation in an Amorphous Ni-P Coating

    SciTech Connect (OSTI)

    Shen, Yongfeng; Liu, Wenning; Sun, Xin; Xue, W. Y.; Wang, Y. D.; Zuo, Liang; Liaw, Peter K.

    2012-05-01T23:59:59.000Z

    An experimental and numerical investigation of the hardness and associated plastic deformation in as-deposited and as-annealed nickel-phosphorus (Ni-P) coatings was conducted. In addition to the indentation-deformation behavior, the deformation morphology underneath the indenter was examined. The yield strength extracted from the indentation data is as high as 5.6 GPa, indicating pressure-sensitive plasticity. Results show that the as-deposited Ni-P coating was deformed appreciably through the shear-band mechanism with semi-circular and radial shear-band morphologies. From the incremental loading-unloading cyclic experiments, the phenomena on hardening and recovery, which have scarcely been recognized in amorphous materials at room temperature, were observed in the amorphous coating using instrumented nanoindentation. A numerical simulation of the interfacial indentation test between the Ni-P coating and the substrate reveals the pile-up and shear bands of the Ni-P coating that were observed during the indentation tests.

  12. Biosynthesis of amorphous mesoporous aluminophosphates using yeast cells as templates

    SciTech Connect (OSTI)

    Sifontes, Ángela B., E-mail: asifonte@ivic.gob.ve [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); González, Gema [Centro de Ingeniería de Materiales y Nanotecnología, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Ingeniería de Materiales y Nanotecnología, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); Tovar, Leidy M.; Méndez, Franklin J. [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); Gomes, Maria E. [Centro de Ingeniería de Materiales y Nanotecnología, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Ingeniería de Materiales y Nanotecnología, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); Cañizales, Edgar [Área de Análisis Químico Inorgánico, PDVSA, INTEVEP, Los Teques 1070-A (Venezuela, Bolivarian Republic of)] [Área de Análisis Químico Inorgánico, PDVSA, INTEVEP, Los Teques 1070-A (Venezuela, Bolivarian Republic of); Niño-Vega, Gustavo; Villalobos, Hector [Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); Brito, Joaquin L. [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)] [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Display Omitted Highlights: ? Amorphous aluminophosphates can take place using yeast as template. ? A mesoporous material was obtained. ? The specific surface area after calcinations ranged between 176 and 214 m{sup 2} g{sup ?1}. -- Abstract: In this study aluminophosphates have been synthesized from aluminum isopropoxide and phosphoric acid solutions using yeast cells as template. The physicochemical characterization was carried out by thermogravimetric analysis; X-ray diffraction; Fourier transform infrared; N{sub 2} adsorption–desorption isotherms; scanning electron microscopy; transmission electron microscopy and potentiometric titration with N-butylamine for determination of: thermal stability; crystalline structure; textural properties; morphology and surface acidity, respectively. The calcined powders consisted of an intimate mixture of amorphous and crystallized AlPO particles with sizes between 23 and 30 nm. The average pore size observed is 13–16 nm and the specific surface area after calcinations (at 650 °C) ranged between 176 and 214 m{sup 2} g{sup ?1}.

  13. Tradeoff regimes of lifetime in amorphous silicon thin-film transistors and a universal lifetime comparison framework

    E-Print Network [OSTI]

    as other TFT technologies. TFTs were first fabricated with a back-channel etched process,3 using "standard were performed in the linear and saturation modes by applying drain-source voltages of 0.1 V for gate is the drain-source voltage, ITFT,lin is the TFT current in the linear mode, L is the channel length, and W

  14. Amorphous Silicon Thin-Film Transistors with DC Saturation Current Half-Life of More than 100 Years

    E-Print Network [OSTI]

    as the time for the TFT drain current to fall by 50% under DC voltage bias in saturation, the half with either back-channel etched (BCE) or back-channel passivated (BCP) structures (Fig. 1). The BCP structure passivates the back-side of the TFT channel "in situ" at the cost of an extra mask step. The gate nitride

  15. Photoresist-free printing of amorphous silicon thin-film transistors Scott M. Miller and Sandra M. Troiana)

    E-Print Network [OSTI]

    Troian, Sandra M.

    growth in the number of nonconventional techniques for the fabrication of electronic devices geared substrate is spin coated with a PS15 and toluene solution. In these studies, the PS thickness was chosen . Studies indicate that rapid separa- tion of liquid coated surfaces distributes the coating evenly between

  16. 304 JOURNAL OF DISPLAY TECHNOLOGY, VOL. 3, NO. 3, SEPTEMBER 2007 Amorphous Silicon Thin-Film Transistor Backplanes

    E-Print Network [OSTI]

    Physics Laboratory, Princeton University, Princeton, NJ. A. Z. Kattamis, I.-C. Cheng, K. Long, B-Film Transistor Backplanes Deposited at 200 C on Clear Plastic for Lamination to Electrophoretic Displays Alex Z. Kattamis, I-Chun Cheng, Ke Long, Bahman Hekmatshoar, Kunigunde H. Cherenack, Sigurd Wagner, James C. Sturm

  17. A 2-terminal perovskite/silicon multijunction solar cell enabled by a silicon tunnel junction

    E-Print Network [OSTI]

    Mailoa, Jonathan P.

    With the advent of efficient high-bandgap metal-halide perovskite photovoltaics, an opportunity exists to make perovskite/silicon tandem solar cells. We fabricate a monolithic tandem by developing a silicon-based interband ...

  18. Amorphization of Zr3Fe under electron irradiation A.T. Motta a,*, L.M. Howe b

    E-Print Network [OSTI]

    Motta, Arthur T.

    Laboratories, Chalk River, Ontario, Canada K0J 1J0 c Materials Science Division, Argonne National Laboratory and specimen orientation on the amorphization process. The critical temperature and the critical dose.e. the critical temperature and critical dose for amorphization. We also compare amorphization induced by electron

  19. Electrostatically defined quantum dots in a Si/SiGe heterostructure This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    Electrostatically defined quantum dots in a Si/SiGe heterostructure This article has been of Physics Electrostatically defined quantum dots in a Si/SiGe heterostructure A Wild1 , J Sailer1 , J Nützel epitaxially grown Si/SiGe heterostructure. Transport and charge spectroscopy with an additional QD as well

  20. 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.