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Sample records for wide bandgap semiconductors

  1. Wide Bandgap Semiconductors | Department of Energy

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

    Wide Bandgap Semiconductors Wide Bandgap Semiconductors Addthis Duration 1:55 Topic Energy Sector Jobs Manufacturing Transmission Innovation

  2. INFOGRAPHIC: Wide Bandgap Semiconductors | Department of Energy

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

    INFOGRAPHIC: Wide Bandgap Semiconductors INFOGRAPHIC: Wide Bandgap Semiconductors January 21, 2014 - 12:44pm Addthis INFOGRAPHIC: Wide Bandgap Semiconductors MORE RESOURCES Watch the video on WBG semiconductors Read the Advanced Manufacturing Office fact sheet on WBG semiconductors Subscribe to Advanced Manufacturing Office news updates Learn about the Clean Energy Manufacturing Initiative For decades, power electronics - or tiny pieces of equipment such as inverters and rectifiers made of

  3. Opportunities for Wide Bandgap Semiconductor Power Electronics...

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

    Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell ... kgd H2 produced) Fuel Cell System Cost Transportation projected to (500,000 ...

  4. Sandia Wide-Bandgap Semiconductor Workshop

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

    ... In response to increased interest in wide-bandgap (WBG) semiconductor projects by DOE, on October 30, 2012, Sandia hosted a one-day brain-storming workshop aimed at identifying the ...

  5. Wide Bandgap Semiconductors: Pursuing the Promise | Department of Energy

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

    Wide Bandgap Semiconductors: Pursuing the Promise Wide Bandgap Semiconductors: Pursuing the Promise Wide bandgap semiconductor materials are more efficient than their silicon-based counterparts; making it possible to reduce weight, volume, and life-cycle costs in a wide range of power applications. Wide Bandgap Semiconductors: Pursuing the Promise (1.37 MB) More Documents & Publications Wide Bandgap Semiconductors for Clean Energy Workshop Vehicle Technologies Office Merit Review 2015:

  6. Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen

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

    and Fuel Cell Applications | Department of Energy for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Download presentation slides from the DOE Fuel Cell Technologies Office webinar "Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications" held on October 21, 2014. Opportunities for Wide Bandgap

  7. Wide Bandgap Semiconductors for Clean Energy Workshop | Department of

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

    Energy Workshops » Wide Bandgap Semiconductors for Clean Energy Workshop Wide Bandgap Semiconductors for Clean Energy Workshop July 25, 2012 A workshop on Wide Bandgap (WBG) Semiconductors for Clean Energy (held July 25, 2012, in Chicago, Illinois) brought together stakeholders from industry and academia to discuss the technical status of WBG semiconductors. The workshop also explored emerging WBG market applications in clean energy and barriers to the development and widespread commercial

  8. Webinar: Opportunities for Wide Bandgap Semiconductor Power Electronics for

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

    Hydrogen and Fuel Cell Applications | Department of Energy Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Webinar: Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Below is the text version of the webinar titled "Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications," originally presented on October 21, 2014. In addition to

  9. Wide Bandgap Semiconductors: Essential to Our Technology Future |

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

    Department of Energy Wide Bandgap Semiconductors: Essential to Our Technology Future Wide Bandgap Semiconductors: Essential to Our Technology Future January 15, 2014 - 8:00am Addthis Learn how wide bandgap semiconductors could impact clean energy technology and our daily lives. | Video by Sarah Gerrity and Matty Greene, Energy Department. Dr. Ernest Moniz Dr. Ernest Moniz Secretary of Energy What are the key facts? North Carolina State University will lead the Energy Department's new

  10. Opportunities for Wide Bandgap Semiconductor Power Electronics...

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

    Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications" held on October 21, 2014. ... Vehicle Technologies Office Merit Review 2016: Advanced Low-Cost SiC and GaN Wide ...

  11. Webinar October 21: Opportunities for Wide Bandgap Semiconductor...

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

    from the development of next-generation power electronics based on wide bandgap (WBG) semiconductor materials such as SiC and GaN. Examples include the development of reliable,...

  12. Wide Bandgap Semiconductors for Clean Energy Workshop Agenda

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

    Wide Bandgap Semiconductors for Clean Energy Workshop ... In the same way that the invention of the silicon chip 50 ... example, as switch-mode power supplies and solar inverters. ...

  13. Comparison of Wide-Bandgap Semiconductors for Power Electronics Applications

    SciTech Connect (OSTI)

    Ozpineci, B.

    2004-01-02

    Recent developmental advances have allowed silicon (Si) semiconductor technology to approach the theoretical limits of the Si material; however, power device requirements for many applications are at a point that the present Si-based power devices cannot handle. The requirements include higher blocking voltages, switching frequencies, efficiency, and reliability. To overcome these limitations, new semiconductor materials for power device applications are needed. For high power requirements, wide-bandgap semiconductors like silicon carbide (SiC), gallium nitride (GaN), and diamond, with their superior electrical properties, are likely candidates to replace Si in the near future. This report compares wide-bandgap semiconductors with respect to their promise and applicability for power applications and predicts the future of power device semiconductor materials.

  14. Wide-Bandgap Compound Semiconductors to Enable Novel Semiconductor Devices

    SciTech Connect (OSTI)

    Crawford, M.H.; Chow, W.W.; Wright, A.F.; Lee, S.R.; Jones, E.D.; Han, J.; Shul, R.J.

    1999-04-01

    This report represents the completion of a three-year Laboratory-Directed Research and Development (LDRD) program that focused on research and development of GaN-based wide bandgap semiconductor materials (referred to as III-N materials). Our theoretical investigations include the determination of fundamental materials parameters from first-principles calculations, the study of gain properties of III-N heterostructures using a microscopic laser theory and density-functional-theory, charge-state calculations to determine the core structure and energy levels of dislocations in III-N materials. Our experimental investigations include time-resolved photoluminescence and magneto-luminescence studies of GaN epilayers and multiquantum well samples as well as x-ray diffraction studies of AlGaN ternary alloys. In addition, we performed a number of experiments to determine how various materials processing steps affect both the optical and electrical properties of GaN-based materials. These studies include photoluminescence studies of GaN epilayers after post-growth rapid thermal annealing, ion implantation to produce n- and p-type material and electrical and optical studies of plasma-etched structures.

  15. Method of depositing wide bandgap amorphous semiconductor materials

    DOE Patents [OSTI]

    Ellis, Jr., Frank B.; Delahoy, Alan E.

    1987-09-29

    A method of depositing wide bandgap p type amorphous semiconductor materials on a substrate without photosensitization by the decomposition of one or more higher order gaseous silanes in the presence of a p-type catalytic dopant at a temperature of about 200.degree. C. and a pressure in the range from about 1-50 Torr.

  16. Photocell utilizing a wide-bandgap semiconductor material

    DOE Patents [OSTI]

    Carlson, David E.; Williams, Brown F.

    1984-06-05

    A photocell comprises a p-i-n amorphous silicon structure having a wide bandgap layer adjacent to either the p-type or n-type layer. This structure reduces the absorption of light entering the photocell and the back-diffusion of minority carriers.

  17. Webinar: Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications

    Broader source: Energy.gov [DOE]

    The Energy Department will present a live webinar titled "Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications" on Tuesday, October 21, at 12:00 p...

  18. Webinar October 21: Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications

    Broader source: Energy.gov [DOE]

    The Energy Department will present a live webinar titled "Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications" on Tuesday, October 21, from 12:00 to 1:00 p.m. Eastern Daylight Time. Representatives of Cree Inc., leading innovators in the WBG electronics industry, will be presenting.

  19. Method and apparatus for use of III-nitride wide bandgap semiconductors in optical communications

    DOE Patents [OSTI]

    Hui, Rongqing; Jiang,Hong-Xing; Lin, Jing-Yu

    2008-03-18

    The present disclosure relates to the use of III-nitride wide bandgap semiconductor materials for optical communications. In one embodiment, an optical device includes an optical waveguide device fabricated using a III-nitride semiconductor material. The III-nitride semiconductor material provides for an electrically controllable refractive index. The optical waveguide device provides for high speed optical communications in an infrared wavelength region. In one embodiment, an optical amplifier is provided using optical coatings at the facet ends of a waveguide formed of erbium-doped III-nitride semiconductor materials.

  20. Webinar October 21: Opportunities for Wide Bandgap Semiconductor...

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

    Articles DOE Announces Webinars on High Performance Space Conditioning Systems, Davis-Bacon Act Compliance, and More DOE Announces Webinars on Zero Energy Ready Homes, Wide...

  1. Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications

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

    Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications U.S. Department of Energy Fuel Cell Technologies Office Presenters: Jeff Casady and John Palmour of Cree Inc. DOE Hosts: Eric Miller and Anant Agarwal 2 Question and Answer * Please type your question into the question box hydrogenandfuelcells.energy.gov 3 | Fuel Cell Technologies Office eere.energy.gov DOE Fuel Cell Technologies Office covers Research, Development, Demonstration &

  2. Chapter 6: Innovating Clean Energy Technologies in Advanced Manufacturing | Wide Bandgap Semiconductors for Power Electronics Technology Assessment

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

    Wide Bandgap Semiconductors for Power Electronics Chapter 6: Technology Assessments NOTE: This technology assessment is available as an appendix to the 2015 Quadrennial Technology Review (QTR). Wide Bandgap Semiconductors for Power Electronics is one of fourteen manufacturing-focused technology assessments prepared in support of Chapter 6: Innovating Clean Energy Technologies in Advanced Manufacturing. For context within the 2015 QTR, key connections between this technology assessment, other QTR

  3. DOE Announces Webinars on Zero Energy Ready Homes, Wide Bandgap...

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

    October 21: Live Webinar on Opportunities for Wide Bandgap Semiconductor Power Electronics ... "Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and ...

  4. System and method of modulating electrical signals using photoconductive wide bandgap semiconductors as variable resistors

    DOE Patents [OSTI]

    Harris, John Richardson; Caporaso, George J; Sampayan, Stephen E

    2013-10-22

    A system and method for producing modulated electrical signals. The system uses a variable resistor having a photoconductive wide bandgap semiconductor material construction whose conduction response to changes in amplitude of incident radiation is substantially linear throughout a non-saturation region to enable operation in non-avalanche mode. The system also includes a modulated radiation source, such as a modulated laser, for producing amplitude-modulated radiation with which to direct upon the variable resistor and modulate its conduction response. A voltage source and an output port, are both operably connected to the variable resistor so that an electrical signal may be produced at the output port by way of the variable resistor, either generated by activation of the variable resistor or propagating through the variable resistor. In this manner, the electrical signal is modulated by the variable resistor so as to have a waveform substantially similar to the amplitude-modulated radiation.

  5. Wide Bandgap Extrinsic Photoconductive Switches

    SciTech Connect (OSTI)

    Sullivan, J S

    2012-01-17

    Photoconductive semiconductor switches (PCSS) have been investigated since the late 1970s. Some devices have been developed that withstand tens of kilovolts and others that switch hundreds of amperes. However, no single device has been developed that can reliably withstand both high voltage and switch high current. Yet, photoconductive switches still hold the promise of reliable high voltage and high current operation with subnanosecond risetimes. Particularly since good quality, bulk, single crystal, wide bandgap semiconductor materials have recently become available. In this chapter we will review the basic operation of PCSS devices, status of PCSS devices and properties of the wide bandgap semiconductors 4H-SiC, 6H-SiC and 2H-GaN.

  6. Wide Bandgap Materials | Department of Energy

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

    1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation ape007_chinthavali_2011_o.pdf (472.25 KB) More Documents & Publications Wide Bandgap Materials Wide Bandgap Materials High Temperature, High Voltage Fully Integrated Gate Driver Circuit

  7. AMO's New Institute Focused on Wide Bandgap Power Electronics...

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

    Focused on Wide Bandgap Power Electronics Manufacturing AMO's New Institute Focused on Wide Bandgap Power Electronics Manufacturing January 15, 2014 - 11:34am Addthis The Next ...

  8. DOE Traineeship In Power Engineering (Leveraging Wide Bandgap...

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

    DOE Traineeship In Power Engineering (Leveraging Wide Bandgap Power Electronics) DOE Traineeship In Power Engineering (Leveraging Wide Bandgap Power Electronics) July 20, 2015 -...

  9. Physical properties and analytical models of band-to-band tunneling in low-bandgap semiconductors

    SciTech Connect (OSTI)

    Shih, Chun-Hsing Dang Chien, Nguyen

    2014-01-28

    Low-bandgap semiconductors, such as InAs and InSb, are widely considered to be ideal for use in tunnel field-effect transistors to ensure sufficient on-current boosting at low voltages. This work elucidates the physical and mathematical considerations of applying conventional band-to-band tunneling models in low-bandgap semiconductors, and presents a new analytical alternative for practical use. The high-bandgap tunneling generates most at maximum field region with shortest tunnel path, whereas the low-bandgap generations occur dispersedly because of narrow tunnel barrier. The local electrical field associated with tunneling-electron numbers dominates in low-bandgap materials. This work proposes decoupled electric-field terms in the pre-exponential factor and exponential function of generation-rate expressions. Without fitting, the analytical results and approximated forms exhibit great agreements with the sophisticated forms both in high- and low-bandgap semiconductors. Neither nonlocal nor local field is appropriate to be used in numerical simulations for predicting the tunneling generations in a variety of low- and high-bandgap semiconductors.

  10. Composition/bandgap selective dry photochemical etching of semiconductor materials

    DOE Patents [OSTI]

    Ashby, C.I.H.; Dishman, J.L.

    1985-10-11

    Disclosed is a method of selectively photochemically dry etching a first semiconductor material of a given composition and direct bandgap Eg/sub 1/ in the presence of a second semiconductor material of a different composition and direct bandgap Eg/sub 2/, wherein Eg/sub 2/ > Eg/sub 1/, said second semiconductor material substantially not being etched during said method. The method comprises subjecting both materials to the same photon flux and to the same gaseous etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said photons being of an energy greater than Eg/sub 1/ but less than Eg/sub 2/, whereby said first semiconductor material is photochemically etched and said second material is substantially not etched.

  11. Composition/bandgap selective dry photochemical etching of semiconductor materials

    DOE Patents [OSTI]

    Ashby, Carol I. H.; Dishman, James L.

    1987-01-01

    A method of selectively photochemically dry etching a first semiconductor material of a given composition and direct bandgap Eg.sub.1 in the presence of a second semiconductor material of a different composition and direct bandgap Eg.sub.2, wherein Eg.sub.2 >Eg.sub.1, said second semiconductor material substantially not being etched during said method, comprises subjecting both materials to the same photon flux and to the same gaseous etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said photons being of an energy greater than Eg.sub.1 but less than Eg.sub.2, whereby said first semiconductor material is photochemically etched and said second material is substantially not etched.

  12. Wide Bandgap Semiconductors: Pursuing the Promise

    Office of Environmental Management (EM)

    Who Uses Open Data? Who Uses Open Data? July 15, 2013 - 10:35am Addthis Who Uses Open Data? Ian Kalin Director of the Energy Data Initiative Company Testimonials on Open Data This list is neither all-inclusive nor static. It is meant to be a growing repository of open data use cases: Appallicious offers a mobile commerce platform, tailored for governments to deliver services to their citizens. The tools are helping cities like San Francisco, which uses open data from the city and county on parks

  13. Electrically pumped edge-emitting photonic bandgap semiconductor laser

    DOE Patents [OSTI]

    Lin, Shawn-Yu; Zubrzycki, Walter J.

    2004-01-06

    A highly efficient, electrically pumped edge-emitting semiconductor laser based on a one- or two-dimensional photonic bandgap (PBG) structure is described. The laser optical cavity is formed using a pair of PBG mirrors operating in the photonic band gap regime. Transverse confinement is achieved by surrounding an active semiconductor layer of high refractive index with lower-index cladding layers. The cladding layers can be electrically insulating in the passive PBG mirror and waveguide regions with a small conducting aperture for efficient channeling of the injection pump current into the active region. The active layer can comprise a quantum well structure. The quantum well structure can be relaxed in the passive regions to provide efficient extraction of laser light from the active region.

  14. Wide band gap semiconductor templates

    DOE Patents [OSTI]

    Arendt, Paul N.; Stan, Liliana; Jia, Quanxi; DePaula, Raymond F.; Usov, Igor O.

    2010-12-14

    The present invention relates to a thin film structure based on an epitaxial (111)-oriented rare earth-Group IVB oxide on the cubic (001) MgO terminated surface and the ion-beam-assisted deposition ("IBAD") techniques that are amendable to be over coated by semiconductors with hexagonal crystal structures. The IBAD magnesium oxide ("MgO") technology, in conjunction with certain template materials, is used to fabricate the desired thin film array. Similarly, IBAD MgO with appropriate template layers can be used for semiconductors with cubic type crystal structures.

  15. Electronic and chemical structure of an organic light emitter embedded in an inorganic wide-bandgap semiconductor: Photoelectron spectroscopy of layered and composite structures of Ir(BPA) and ZnSe

    SciTech Connect (OSTI)

    Dimamay, Mariel; Mayer, Thomas; Jaegermann, Wolfram; Hadziioannou, Georges

    2015-05-07

    Luminescent organic phases embedded in conductive inorganic matrices are proposed for hybrid organic-inorganic light-emitting diodes. In this configuration, the organic dye acts as the radiative recombination site for charge carriers injected into the inorganic matrix. Our investigation is aimed at finding a material combination where the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the organic dye are situated in between the valence and conduction bands of the inorganic matrix in order to promote electron and hole transfer from the matrix to the dye. Bilayer and composite thin films of zinc selenide (ZnSe) and a red iridium complex (Ir(BPA)) organic light emitter were prepared in situ via UHV thermal evaporation technique. The electronic and atomic structures were studied applying X-ray and ultraviolet photoelectron spectroscopies. The measured energy band alignments for the ZnSe/Ir(BPA) bilayer and ZnSe+Ir(BPA) composite reveal that the HOMO and LUMO of the organic dye are positioned in the ZnSe bandgap. For the initial steps of ZnSe deposition on a dye film to form Ir(BPA)/ZnSe bilayers, zinc atoms intercalate into the dye film leaving behind an excess of selenium at the interface that partly reacts with dye molecules. Photoelectron spectroscopy of the composites shows the same species suggesting a similar mechanism. This mechanism leads to composite films with increased content of amorphous phases in the inorganic matrix, thereby affecting its conductivity, as well as to the presence of nonradiative recombination sites provided by the intercalated Zn atoms.

  16. Enhanced conversion efficiency in wide-bandgap GaNP solar cells...

    Office of Scientific and Technical Information (OSTI)

    Enhanced conversion efficiency in wide-bandgap GaNP solar cells Citation Details In-Document Search This content will become publicly available on October 12, 2016 Title: Enhanced...

  17. High-voltage field effect transistors with wide-bandgap β-Ga{sub 2}O{sub 3} nanomembranes

    SciTech Connect (OSTI)

    Hwang, Wan Sik E-mail: djena@nd.edu; Verma, Amit; Protasenko, Vladimir; Rouvimov, Sergei; Xing, Huili; Seabaugh, Alan; Jena, Debdeep E-mail: djena@nd.edu; Peelaers, Hartwin; Van de Walle, Chris; Haensch, Wilfried; Galazka, Zbigniew; Albrecht, Martin; Fornari, Roberto

    2014-05-19

    Nanoscale semiconductor materials have been extensively investigated as the channel materials of transistors for energy-efficient low-power logic switches to enable scaling to smaller dimensions. On the opposite end of transistor applications is power electronics for which transistors capable of switching very high voltages are necessary. Miniaturization of energy-efficient power switches can enable the integration with various electronic systems and lead to substantial boosts in energy efficiency. Nanotechnology is yet to have an impact in this arena. In this work, it is demonstrated that nanomembranes of the wide-bandgap semiconductor gallium oxide can be used as channels of transistors capable of switching high voltages, and at the same time can be integrated on any platform. The findings mark a step towards using lessons learnt in nanomaterials and nanotechnology to address a challenge that yet remains untouched by the field.

  18. Webinar: Opportunities for Wide Bandgap Semiconductor Power Electronic...

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

    ... customers have different cost structures, but it's ... much space, because the solar panels have gotten so cheap now ... What is the labor involved in installing an inverter that ...

  19. Wide Bandgap Semiconductors for Clean Energy Workshop: Summary...

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

    ... devices and decrease lifetime of other elements. o Manage heat by improving efficiency. ... Chip. Quantum Dot Phosphors (cadmium-free), Rare Earth Mitigation-Longevity Questions. ...

  20. DOE Traineeship In Power Engineering (Leveraging Wide Bandgap Power Electronics)

    Broader source: Energy.gov [DOE]

    The Advanced Manufacturing Office announced up to $10 million is available to establish 5-year graduate-level university-led DOE Traineeship(s) in Power Engineering (leveraging emerging Wide...

  1. Novel Approaches to Wide Bandgap CuInSe2 Based Absorbers

    SciTech Connect (OSTI)

    William N. Shafarman

    2011-04-28

    This project targeted the development of high performance wide bandgap solar cells based on thin film alloys of CuInSe2 to relax constraints on module design and enable tandem solar cell structures. This addressed goals of the Solar Energy Technologies Program for Next Generation PV to develop technology needed for higher thin film module efficiency as a means to reduce costs. Specific objectives of the research project were: 1) to develop the processes and materials required to improve the performance of wide bandgap thin film solar cells based on alloys of CuInSe2, and 2) to provide the fundamental science and engineering basis for the material, electronic, and device properties required to effectively apply these processes and materials to commercial manufacture. CuInSe2-based photovoltaics have established the highest efficiencies of the thin film materials at both the cell and module scales and are actively being scaled up to commercialization. In the highest efficiency cells and modules, the optical bandgap, a function of the CuInSe2-based alloy composition, is relatively low compared to the optimum match to the solar spectrum. Wider bandgap alloys of CuInSe2 produce higher cell voltages which can improve module performance and enable the development of tandem solar cells to boost the overall efficiency. A focus for the project was alloying with silver to form (AgCu)(InGa)Se2 pentenary thin films deposited by elemental co-evaporation which gives the broadest range of control of composition and material properties. This alloy has a lower melting temperature than Ag-free, Cu-based chalcopyrite compounds, which may enable films to be formed with lower defect densities and the (AgCu)(InGa)Se2 films give improved material properties and better device performance with increasing bandgap. A comprehensive characterization of optical, structural, and electronic properties of (AgCu)(InGa)Se2 was completed over the complete compositional range 0 ≤ Ga/(In+Ga) ≤ 1 and

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

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

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

  3. Wide bandgap OPV polymers based on pyridinonedithiophene unit with efficiency >5%

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

    Schneider, Alexander M.; Lu, Luyao; Manley, Eric F.; Zheng, Tianyue; Sharapov, Valerii; Xu, Tao; Marks, Tobin J.; Chen, Lin X.; Yu, Luping

    2015-06-04

    We report the properties of a new series of wide band gap photovoltaic polymers based on the N-alkyl 2-pyridone dithiophene (PDT) unit. These polymers are effective bulk heterojunction solar cell materials when blended with phenyl-C71-butyric acid methyl ester (PC71BM). They achieve power conversion efficiencies (up to 5.33%) high for polymers having such large bandgaps, ca. 2.0 eV (optical) and 2.5 eV (electrochemical). As a result, grazing incidence wide-angle X-ray scattering (GIWAXS) reveals strong correlations between ?? stacking distance and regularity, polymer backbone planarity, optical absorption maximum energy, and photovoltaic efficiency.

  4. High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy

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

    converters - Energy Innovation Portal High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters National Renewable Energy Laboratory Contact NREL About This Technology Technology Marketing Summary Matching a semiconductor's bandgap to incident photon energy is a well-known method to achieve the most efficient photovoltaic devices. Since solar radiation consists of a wide range of wavelengths, having one semiconductor with a single bandgap to absorb all solar radiation

  5. Wide bandgap OPV polymers based on pyridinonedithiophene unit with efficiency >5%

    SciTech Connect (OSTI)

    Schneider, Alexander M.; Lu, Luyao; Manley, Eric F.; Zheng, Tianyue; Sharapov, Valerii; Xu, Tao; Marks, Tobin J.; Chen, Lin X.; Yu, Luping

    2015-06-04

    We report the properties of a new series of wide band gap photovoltaic polymers based on the N-alkyl 2-pyridone dithiophene (PDT) unit. These polymers are effective bulk heterojunction solar cell materials when blended with phenyl-C71-butyric acid methyl ester (PC71BM). They achieve power conversion efficiencies (up to 5.33%) high for polymers having such large bandgaps, ca. 2.0 eV (optical) and 2.5 eV (electrochemical). As a result, grazing incidence wide-angle X-ray scattering (GIWAXS) reveals strong correlations between ?? stacking distance and regularity, polymer backbone planarity, optical absorption maximum energy, and photovoltaic efficiency.

  6. Wide bandgap OPV polymers based on pyridinonedithiophene unit with efficiency >5%

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

    Schneider, Alexander M.; Lu, Luyao; Manley, Eric F.; Zheng, Tianyue; Sharapov, Valerii; Xu, Tao; Marks, Tobin J.; Chen, Lin X.; Yu, Luping

    2015-06-04

    We report the properties of a new series of wide band gap photovoltaic polymers based on the N-alkyl 2-pyridone dithiophene (PDT) unit. These polymers are effective bulk heterojunction solar cell materials when blended with phenyl-C71-butyric acid methyl ester (PC71BM). They achieve power conversion efficiencies (up to 5.33%) high for polymers having such large bandgaps, ca. 2.0 eV (optical) and 2.5 eV (electrochemical). As a result, grazing incidence wide-angle X-ray scattering (GIWAXS) reveals strong correlations between π–π stacking distance and regularity, polymer backbone planarity, optical absorption maximum energy, and photovoltaic efficiency.

  7. Fabrication of stable, wide-bandgap thin films of Mg, Zn and O

    DOE Patents [OSTI]

    Katiyar, Ram S.; Bhattacharya, Pijush; Das, Rasmi R.

    2006-07-25

    A stable, wide-bandgap (approximately 6 eV) ZnO/MgO multilayer thin film is fabricated using pulsed-laser deposition on c-plane Al2O3 substrates. Layers of ZnO alternate with layers of MgO. The thickness of MgO is a constant of approximately 1 nm; the thicknesses of ZnO layers vary from approximately 0.75 to 2.5 nm. Abrupt structural transitions from hexagonal to cubic phase follow a decrease in the thickness of ZnO sublayers within this range. The band gap of the thin films is also influenced by the crystalline structure of multilayer stacks. Thin films with hexagonal and cubic structure have band-gap values of 3.5 and 6 eV, respectively. In the hexagonal phase, Mg content of the films is approximately 40%; in the cubic phase Mg content is approximately 60%. The thin films are stable and their structural and optical properties are unaffected by annealing at 750.degree. C.

  8. Band-Gap Engineering at a Semiconductor-Crystalline Oxide Interface

    SciTech Connect (OSTI)

    Jahangir-Moghadam, Mohammadreza; Ahmadi-Majlan, Kamyar; Shen, Xuan; Droubay, Timothy; Bowden, Mark; Chrysler, Matthew; Su, Dong; Chambers, Scott A.; Ngai, Joseph H.

    2015-02-09

    The epitaxial growth of crystalline oxides on semiconductors provides a pathway to introduce new functionalities to semiconductor devices. Key to integrating the functionalities of oxides onto semiconductors is controlling the band alignment at interfaces between the two materials. Here we apply principles of band gap engineering traditionally used at heterojunctions between conventional semiconductors to control the band offset between a single crystalline oxide and a semiconductor. Reactive molecular beam epitaxy is used to realize atomically abrupt and structurally coherent interfaces between SrZrxTi1-xO? and Ge, in which the band gap of the former is enhanced with Zr content x. We present structural and electrical characterization of SrZrxTi1-xO?-Ge heterojunctions and demonstrate a type-I band offset can be achieved. These results demonstrate that band gap engineering can be exploited to realize functional semiconductor crystalline oxide heterojunctions.

  9. Band-Gap Engineering at a Semiconductor-Crystalline Oxide Interface

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

    Jahangir-Moghadam, Mohammadreza; Ahmadi-Majlan, Kamyar; Shen, Xuan; Droubay, Timothy; Bowden, Mark; Chrysler, Matthew; Su, Dong; Chambers, Scott A.; Ngai, Joseph H.

    2015-02-09

    The epitaxial growth of crystalline oxides on semiconductors provides a pathway to introduce new functionalities to semiconductor devices. Key to integrating the functionalities of oxides onto semiconductors is controlling the band alignment at interfaces between the two materials. Here we apply principles of band gap engineering traditionally used at heterojunctions between conventional semiconductors to control the band offset between a single crystalline oxide and a semiconductor. Reactive molecular beam epitaxy is used to realize atomically abrupt and structurally coherent interfaces between SrZrxTi1-xO₃ and Ge, in which the band gap of the former is enhanced with Zr content x. We presentmore » structural and electrical characterization of SrZrxTi1-xO₃-Ge heterojunctions and demonstrate a type-I band offset can be achieved. These results demonstrate that band gap engineering can be exploited to realize functional semiconductor crystalline oxide heterojunctions.« less

  10. Stabilized wide bandgap MAPbBrxI3-x perovskite by enhanced grain size and improved crystallinity

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

    Hu, Miao; Bi, Cheng; Yuan, Yongbo; Bai, Yang; Huang, Jinsong

    2015-12-07

    In this study, the light instability of CH3NH3PbIxBr3–x has been raised one of the biggest challenges for its application in tandem solar cells. Here we show that an improved crystallinity and grain size of CH3NH3PbIxBr3–x films could stabilize these materials under one sun illumination, improving both the efficiency and stability of the wide-bandgap perovskite solar cells.

  11. Widely tunable two-color FEL pulses at FERMI | Stanford Synchrotron

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

    Department of Energy Wide Bandgap Semiconductors: Essential to Our Technology Future Wide Bandgap Semiconductors: Essential to Our Technology Future January 15, 2014 - 8:00am Addthis Learn how wide bandgap semiconductors could impact clean energy technology and our daily lives. | Video by Sarah Gerrity and Matty Greene, Energy Department. Dr. Ernest Moniz Dr. Ernest Moniz Secretary of Energy What are the key facts? North Carolina State University will lead the Energy Department's new

  12. Low-temperature fabrication of efficient wide-bandgap organolead trihalide perovskite solar cells

    SciTech Connect (OSTI)

    Bi, Cheng; Yuan, Yongbo; Fang, Yanjun; Huang, Jinsong

    2014-11-25

    A mixed halide perovskite solar cell with a 1.72 eV bandgap is developed by incorporating Br into perovskite through a low-temperature solution process. A high efficiency of 13.1% is achieved by carefully tuning the thickness, morphology, and surface passivation of the perovskite layers. Furthermore, the fabrication techniques and conditions are compatible with future perovskite/Si tandem cell studies.

  13. Enhanced conversion efficiency in wide-bandgap GaNP solar cells

    SciTech Connect (OSTI)

    Sukrittanon, Supanee; Liu, Ren; Ro, Yun Goo; Pan, Janet L.; Jungjohann, Katherine Leigh; Tu, Charles W.; Dayeh, Shadi A.

    2015-10-12

    In this study, we demonstrate –2.05 eV dilute nitride GaNP solar cells on GaP substrates for potential use as the top junction in dual-junction integrated cells on Si. By adding a small amount of N into indirect-bandgap GaP, GaNP has several extremely important attributes: a direct-bandgap that is also tunable, and easily attained lattice-match with Si. Our best GaNP solar cell ([N] –1.8%, Eg –2.05 eV) achieves an efficiency of 7.9%, even in the absence of a window layer. This GaNP solar cell's efficiency is 3× higher than the most efficient GaP solar cell to date and higher than other solar cells with similar direct bandgap (InGaP, GaAsP). Through a systematic study of the structural, electrical, and optical properties of the device, efficient broadband optical absorption and enhanced solar cell performance are demonstrated.

  14. Enhanced conversion efficiency in wide-bandgap GaNP solar cells

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

    Sukrittanon, Supanee; Liu, Ren; Ro, Yun Goo; Pan, Janet L.; Jungjohann, Katherine Leigh; Tu, Charles W.; Dayeh, Shadi A.

    2015-10-12

    In this study, we demonstrate –2.05 eV dilute nitride GaNP solar cells on GaP substrates for potential use as the top junction in dual-junction integrated cells on Si. By adding a small amount of N into indirect-bandgap GaP, GaNP has several extremely important attributes: a direct-bandgap that is also tunable, and easily attained lattice-match with Si. Our best GaNP solar cell ([N] –1.8%, Eg –2.05 eV) achieves an efficiency of 7.9%, even in the absence of a window layer. This GaNP solar cell's efficiency is 3× higher than the most efficient GaP solar cell to date and higher than othermore » solar cells with similar direct bandgap (InGaP, GaAsP). Through a systematic study of the structural, electrical, and optical properties of the device, efficient broadband optical absorption and enhanced solar cell performance are demonstrated.« less

  15. Bilayer Graphene Gets a Bandgap

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

    nanoelectronics. This is a narrower bandgap than common semiconductors like silicon or gallium arsenide, and it could enable new kinds of optoelectronic devices for generating,...

  16. Wide Bandgap Power Electronics

    Office of Environmental Management (EM)

    ... coal power plant. 463 In addition to power savings, an important benefit of using high frequency GaN electronics is that the 464 adapter size can be reduced by 10x. Consumers ...

  17. Wide Bandgap Materials

    Broader source: Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  18. Wide Bandgap Power Electronics

    Broader source: Energy.gov [DOE]

    2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

  19. Stabilized wide bandgap MAPbBrxI3-x perovskite by enhanced grain size and improved crystallinity

    SciTech Connect (OSTI)

    Hu, Miao; Bi, Cheng; Yuan, Yongbo; Bai, Yang; Huang, Jinsong

    2015-12-07

    In this study, the light instability of CH3NH3PbIxBr3–x has been raised one of the biggest challenges for its application in tandem solar cells. Here we show that an improved crystallinity and grain size of CH3NH3PbIxBr3–x films could stabilize these materials under one sun illumination, improving both the efficiency and stability of the wide-bandgap perovskite solar cells.

  20. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

  1. DOE Announces Webinars on Zero Energy Ready Homes, Wide Bandgap Semiconductors for Fuel Cell Applications, and More

    Broader source: Energy.gov [DOE]

    EERE offers webinars to the public on a range of subjects, from adopting the latest energy efficiency and renewable energy technologies, to training for the clean energy workforce. Webinars are free; however, advanced registration is typically required. You can also watch archived webinars and browse previously aired videos, slides, and transcripts.

  2. Interview with ARPA-E: The Future of Semiconductors | Department of Energy

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

    Interview with ARPA-E: The Future of Semiconductors Interview with ARPA-E: The Future of Semiconductors February 4, 2014 - 10:56am Addthis Learn how wide bandgap semiconductors could impact clean energy technology and our daily lives. | Video by Sarah Gerrity and Matty Greene, Energy Department. Mark D. Mitchell Communications Support Contractor to ARPA-E What are the key facts? ARPA-E's SWITCHES program is focused on making the transmission of electricity more efficient by exploring wide

  3. 2012 DEFECTS IN SEMICONDUCTORS GORDON RESEARCH CONFERENCE, AUGUST 12-17, 2012

    SciTech Connect (OSTI)

    GLASER, EVAN

    2012-08-17

    The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

  4. Wide-band-gap, alkaline-earth-oxide semiconductor and devices utilizing same

    DOE Patents [OSTI]

    Abraham, Marvin M.; Chen, Yok; Kernohan, Robert H.

    1981-01-01

    This invention relates to novel and comparatively inexpensive semiconductor devices utilizing semiconducting alkaline-earth-oxide crystals doped with alkali metal. The semiconducting crystals are produced by a simple and relatively inexpensive process. As a specific example, a high-purity lithium-doped MgO crystal is grown by conventional techniques. The crystal then is heated in an oxygen-containing atmosphere to form many [Li].degree. defects therein, and the resulting defect-rich hot crystal is promptly quenched to render the defects stable at room temperature and temperatures well above the same. Quenching can be effected conveniently by contacting the hot crystal with room-temperature air.

  5. Semiconductor-based photoelectrochemical water splitting at the limit of very wide depletion region

    SciTech Connect (OSTI)

    Liu, Mingzhao; Lyons, John L.; Yan, Danhua H.; Hybertsen, Mark S.

    2015-11-23

    In semiconductor-based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at the semiconductor/water interface. As a Schottky junction device, the trade-off between photon collection and minority carrier delivery remains a persistent obstacle for maximizing the performance of a water splitting photoelectrode. Here, it is demonstrated that the PEC water splitting efficiency for an n-SrTiO3 (n-STO) photoanode is improved very significantly despite its weak indirect band gap optical absorption (α < 10⁴ cm⁻¹), by widening the depletion region through engineering its doping density and profile. Graded doped n-SrTiO3 photoanodes are fabricated with their bulk heavily doped with oxygen vacancies but their surface lightly doped over a tunable depth of a few hundred nanometers, through a simple low temperature re-oxidation technique. The graded doping profile widens the depletion region to over 500 nm, thus leading to very efficient charge carrier separation and high quantum efficiency (>70%) for the weak indirect transition. As a result, this simultaneous optimization of the light absorption, minority carrier (hole) delivery, and majority carrier (electron) transport by means of a graded doping architecture may be useful for other indirect band gap photocatalysts that suffer from a similar problem of weak optical absorption.

  6. Semiconductor-based photoelectrochemical water splitting at the limit of very wide depletion region

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

    Liu, Mingzhao; Lyons, John L.; Yan, Danhua H.; Hybertsen, Mark S.

    2015-11-23

    In semiconductor-based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at the semiconductor/water interface. As a Schottky junction device, the trade-off between photon collection and minority carrier delivery remains a persistent obstacle for maximizing the performance of a water splitting photoelectrode. Here, it is demonstrated that the PEC water splitting efficiency for an n-SrTiO3 (n-STO) photoanode is improved very significantly despite its weak indirect band gap optical absorption (α < 10⁴ cm⁻¹), by widening the depletion region through engineering its doping density and profile. Graded doped n-SrTiO3 photoanodes are fabricated with their bulkmore » heavily doped with oxygen vacancies but their surface lightly doped over a tunable depth of a few hundred nanometers, through a simple low temperature re-oxidation technique. The graded doping profile widens the depletion region to over 500 nm, thus leading to very efficient charge carrier separation and high quantum efficiency (>70%) for the weak indirect transition. As a result, this simultaneous optimization of the light absorption, minority carrier (hole) delivery, and majority carrier (electron) transport by means of a graded doping architecture may be useful for other indirect band gap photocatalysts that suffer from a similar problem of weak optical absorption.« less

  7. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest

  8. Properties of Wide-Gap Chalcopyrite Semiconductors for Photovoltaic Applications: Final Report, 8 July 1998 -- 17 October 2001

    SciTech Connect (OSTI)

    Rockett, A.

    2003-07-01

    The objectives of this project were to obtain a fundamental understanding of wide-gap chalcopyrite semiconductors and photovoltaic devices. Information to be gathered included significant new fundamental materials data necessary for accurate modeling of single- and tandem-junction devices, basic materials science of wider-gap chalcopyrite semiconductors to be used in next-generation devices, and practical information on the operation of devices incorporating these materials. Deposition used a hybrid sputtering and evaporation method shown previously to produce high-quality epitaxial layers of Cu(In,Ga)Se2 (CIGS). Materials analysis was also provided to assist members of the National CIS Team, of which, through this contract, we were a member. Solar cells produced from resulting single-crystal epitaxial layers in collaboration with various members of the CIS Team were used to determine the factors limiting performance of the devices based on analysis of the results. Because epitaxial growth allows us to determine the surface orientation of our films specifically by choice of the substrate surface on which the film is grown, a major focus of the project concerned the nature of (110)-oriented CIGS films and the performance of solar cells produced from these films. We begin this summary with a description of the results for growth on (110) GaAs, which formed a basis for much of the work ultimately conducted under the program.

  9. Bilayer Graphene Gets a Bandgap

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

    Bilayer Graphene Gets a Bandgap Bilayer Graphene Gets a Bandgap Print Wednesday, 26 August 2009 00:00 Graphene is the two-dimensional crystalline form of carbon whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But without a bandgap, graphene's promise can't be realized. As with monolayer graphene, bilayer graphene also has a zero bandgap and thus behaves like a metal. But a bandgap can be introduced if an electric

  10. 3D Printed and Semiconductor Technology 'Mash-up' | Department of Energy

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

    3D Printed and Semiconductor Technology 'Mash-up' 3D Printed and Semiconductor Technology 'Mash-up' May 7, 2015 - 4:11pm Addthis 3D Printed and Semiconductor Technology 'Mash-up' What will you get if you put a 3D-printed inverter package with wide bandgap materials, together with the 3D-printed EV version of the Shelby Cobra "plug and play" laboratory-on-wheels? You'll get innovation - innovation that will define even lighter, more powerful, and more efficient vehicles. Oak Ridge

  11. Microfabricated bulk wave acoustic bandgap device (Patent) |...

    Office of Scientific and Technical Information (OSTI)

    Microfabricated bulk wave acoustic bandgap device Title: Microfabricated bulk wave acoustic bandgap device A microfabricated bulk wave acoustic bandgap device comprises a periodic ...

  12. Bilayer Graphene Gets a Bandgap

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

    Bilayer Graphene Gets a Bandgap Bilayer Graphene Gets a Bandgap Print Wednesday, 26 August 2009 00:00 Graphene is the two-dimensional crystalline form of carbon whose extraordinary...

  13. Wide Bandgap Materials | Department of Energy

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

    Department of Energy Why Green is Your Color: A Woman’s Guide to a Sustainable Career "Many occupations in the clean energy economy remain virtually untapped by women," said Sara Manzano-Díaz, director of the Department of Labor's Women's Bureau. To address this challenge, the Women's Bureau, the only federal agency designated to represent the needs of working women, has released a comprehensive guide to preparing, finding, and succeeding in green jobs. Check out the guide

  14. Bilayer Graphene Gets a Bandgap

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

    Bilayer Graphene Gets a Bandgap Print Graphene is the two-dimensional crystalline form of carbon whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But without a bandgap, graphene's promise can't be realized. As with monolayer graphene, bilayer graphene also has a zero bandgap and thus behaves like a metal. But a bandgap can be introduced if an electric displacement field is applied to the two layers; the material then

  15. Bilayer Graphene Gets a Bandgap

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

    Bilayer Graphene Gets a Bandgap Print Graphene is the two-dimensional crystalline form of carbon whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But without a bandgap, graphene's promise can't be realized. As with monolayer graphene, bilayer graphene also has a zero bandgap and thus behaves like a metal. But a bandgap can be introduced if an electric displacement field is applied to the two layers; the material then

  16. Bilayer Graphene Gets a Bandgap

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

    Bilayer Graphene Gets a Bandgap Print Graphene is the two-dimensional crystalline form of carbon whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But without a bandgap, graphene's promise can't be realized. As with monolayer graphene, bilayer graphene also has a zero bandgap and thus behaves like a metal. But a bandgap can be introduced if an electric displacement field is applied to the two layers; the material then

  17. L-asparagine crystals with wide gap semiconductor features: Optical absorption measurements and density functional theory computations

    SciTech Connect (OSTI)

    Zanatta, G.; Gottfried, C.; Silva, A. M.; Caetano, E. W. S.; Sales, F. A. M.; Freire, V. N.

    2014-03-28

    Results of optical absorption measurements are presented together with calculated structural, electronic, and optical properties for the anhydrous monoclinic L-asparagine crystal. Density functional theory (DFT) within the generalized gradient approximation (GGA) including dispersion effects (TS, Grimme) was employed to perform the calculations. The optical absorption measurements revealed that the anhydrous monoclinic L-asparagine crystal is a wide band gap material with 4.95 eV main gap energy. DFT-GGA+TS simulations, on the other hand, produced structural parameters in very good agreement with X-ray data. The lattice parameter differences ?a, ?b, ?c between theory and experiment were as small as 0.020, 0.051, and 0.022, respectively. The calculated band gap energy is smaller than the experimental data by about 15%, with a 4.23 eV indirect band gap corresponding to Z???? and Z???? transitions. Three other indirect band gaps of 4.30 eV, 4.32 eV, and 4.36 eV are assigned to ?3 ???, ?1 ???, and ?2 ??? transitions, respectively. ?-sol computations, on the other hand, predict a main band gap of 5.00 eV, just 50 meV above the experimental value. Electronic wavefunctions mainly originating from O 2pcarboxyl, C 2pside chain, and C 2pcarboxyl orbitals contribute most significantly to the highest valence and lowest conduction energy bands, respectively. By varying the lattice parameters from their converged equilibrium values, we show that the unit cell is less stiff along the b direction than for the a and c directions. Effective mass calculations suggest that hole transport behavior is more anisotropic than electron transport, but the mass values allow for some charge mobility except along a direction perpendicular to the molecular layers of L-asparagine which form the crystal, so anhydrous monoclinic L-asparagine crystals could behave as wide gap semiconductors. Finally, the calculations point to a high degree of optical anisotropy for the absorption and complex

  18. Bilayer Graphene Gets a Bandgap

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

    Bilayer Graphene Gets a Bandgap Print Graphene is the two-dimensional crystalline form of carbon whose extraordinary electron mobility and other unique features hold great promise...

  19. Bilayer Graphene Gets a Bandgap

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

    extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But without a bandgap, graphene's promise can't be realized. ...

  20. Bilayer Graphene Gets a Bandgap

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

    metal atoms. But such chemical doping is uncontrolled and not compatible with device applications. Researchers then tried to tune the bilayer graphene bandgap by doping the...

  1. Development of Spintronic Bandgap Materials (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Development of Spintronic Bandgap Materials Citation Details In-Document Search Title: Development of Spintronic Bandgap Materials The development of GeSi ...

  2. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  3. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  4. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  5. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  6. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key

  7. Bilayer Graphene Gets a Bandgap

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

    electronic bandgap and the charge doping. The device was a dual-gated field-effect transistor (FET), a type of transistor that controls the flow of electrons from a source to a...

  8. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    SciTech Connect (OSTI)

    Black, Marcie

    2014-10-31

    This report details some of our studies and proposes future methods of exploring Bandgap Activation.

  9. Low-bandgap, monolithic, multi-bandgap, optoelectronic devices

    DOE Patents [OSTI]

    Wanlass, Mark W.; Carapella, Jeffrey J.

    2016-03-22

    Low bandgap, monolithic, multi-bandgap, optoelectronic devices (10), including PV converters, photodetectors, and LED's, have lattice-matched (LM), double-heterostructure (DH), low-bandgap GaInAs(P) subcells (22, 24) including those that are lattice-mismatched (LMM) to InP, grown on an InP substrate (26) by use of at least one graded lattice constant transition layer (20) of InAsP positioned somewhere between the InP substrate (26) and the LMM subcell(s) (22, 24). These devices are monofacial (10) or bifacial (80) and include monolithic, integrated, modules (MIMs) (190) with a plurality of voltage-matched subcell circuits (262, 264, 266, 270, 272) as well as other variations and embodiments.

  10. Low-bandgap, monolithic, multi-bandgap, optoelectronic devices

    DOE Patents [OSTI]

    Wanlass, Mark W.; Carapella, Jeffrey J.

    2016-01-05

    Low bandgap, monolithic, multi-bandgap, optoelectronic devices (10), including PV converters, photodetectors, and LED's, have lattice-matched (LM), double-heterostructure (DH), low-bandgap GaInAs(P) subcells (22, 24) including those that are lattice-mismatched (LMM) to InP, grown on an InP substrate (26) by use of at least one graded lattice constant transition layer (20) of InAsP positioned somewhere between the InP substrate (26) and the LMM subcell(s) (22, 24). These devices are monofacial (10) or bifacial (80) and include monolithic, integrated, modules (MIMs) (190) with a plurality of voltage-matched subcell circuits (262, 264, 266, 270, 272) as well as other variations and embodiments.

  11. Low-bandgap, monolithic, multi-bandgap, optoelectronic devices

    DOE Patents [OSTI]

    Wanlass, Mark W.; Carapella, Jeffrey J.

    2014-07-08

    Low bandgap, monolithic, multi-bandgap, optoelectronic devices (10), including PV converters, photodetectors, and LED's, have lattice-matched (LM), double-heterostructure (DH), low-bandgap GaInAs(P) subcells (22, 24) including those that are lattice-mismatched (LMM) to InP, grown on an InP substrate (26) by use of at least one graded lattice constant transition layer (20) of InAsP positioned somewhere between the InP substrate (26) and the LMM subcell(s) (22, 24). These devices are monofacial (10) or bifacial (80) and include monolithic, integrated, modules (MIMs) (190) with a plurality of voltage-matched subcell circuits (262, 264, 266, 270, 272) as well as other variations and embodiments.

  12. Development of epitaxial AlxSc1-xN for artificially structured metal/semiconductor superlattice metamaterials

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

    Sands, Timothy D.; Stach, Eric A.; Saha, Bivas; Saber, Sammy; Naik, Gururaj V.; Boltasseva, Alexandra; Kvam, Eric P.

    2015-02-01

    Epitaxial nitride rocksalt metal/semiconductor superlattices are emerging as a novel class of artificially structured materials that have generated significant interest in recent years for their potential application in plasmonic and thermoelectric devices. Though most nitride metals are rocksalt, nitride semiconductors in general have hexagonal crystal structure. We report rocksalt aluminum scandium nitride (Al,Sc)N alloys as the semiconducting component in epitaxial rocksalt metal/semiconductor superlattices. The AlxSc1-xN alloys when deposited directly on MgO substrates are stabilized in a homogeneous rocksalt (single) phase when x < 0.51. Employing 20 nm TiN as a seed layer on MgO substrates, the homogeneity range for stabilizingmore » the rocksalt phase has been extended to x < 0.82 for a 120 nm film. The rocksalt AlxSc1-xN alloys show moderate direct bandgap bowing with a bowing parameter, B = 1.41 ± 0.19 eV. The direct bandgap of metastable rocksalt AlN is extrapolated to be 4.70 ± 0.20 eV. The tunable lattice parameter, bandgap, dielectric permittivity, and electronic properties of rocksalt AlxSc1-xN alloys enable high quality epitaxial rocksalt metal/AlxSc1-xN superlattices with a wide range of accessible metamaterials properties.« less

  13. Luminescence in Conjugated Molecular Materials under Sub-bandgap Excitation

    SciTech Connect (OSTI)

    So, Franky

    2014-05-08

    Light emission in semiconductors occurs when they are under optical and electrical excitation with energy larger than the bandgap energy. In some low-dimensional semiconductor heterostructure systems, this thermodynamic limit can be violated due to radiative Auger recombination (AR), a process in which the sub-bandgap energy released from a recombined electron-hole pair is transferred to a third particle leading to radiative band-to-band recombination.1 Thus far, photoluminescence up-conversion phenomenon has been observed in some low dimensional semiconductor systems, and the effect is very weak and it can only be observed at low temperatures. Recently, we discovered that efficient electroluminescence in poly[2-methoxy-5-(2-ethylhexyloxy)-1, phenylenevinylene] (MEH-PPV) polymer light-emitting devices (PLEDs) at drive voltages below its bandgap voltage could be observed when a ZnO nanoparticles (NPs) electron injection layer was inserted between the polymer and the aluminum electrode. Specifically, emitted photons with energy of 2.13 eV can be detected at operating voltages as low as 1.2 V at room temperature. Based on these data, we propose that the sub-bandgap turn-on in the MEH-PPV device is due to an Auger-assisted energy up-conversion process. The significance of this discovery is three-fold. First, radiative recombination occurs at operating voltages below the thermodynamic bandgap voltage. This process can significantly reduce the device operating voltage. For example, the current density of the device with the ZnO NC layer is almost two orders of magnitude higher than that of the device without the NC layer. Second, a reactive metal is no longer needed for the cathode. Third, this electroluminescence up-conversion process can be applied to inorganic semiconductors systems as well and their operation voltages of inorganic LEDs can be reduced to about half of the bandgap energy. Based on our initial data, we propose that the sub-bandgap turn-on in MEH

  14. Vehicle Technologies Office Merit Review 2014: Advanced Low-Cost SiC and GaN Wide Bandgap Inverters for Under-the-Hood Electric Vehicle Traction Drives

    Broader source: Energy.gov [DOE]

    Presentation given by APEI Inc. at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about Advanced low-cost SIC and GaN wide...

  15. Vehicle Technologies Office Merit Review 2015: Advanced Low-Cost SiC and GaN Wide Bandgap Inverters for Under-the-Hood Electric Vehicle Traction Drives

    Broader source: Energy.gov [DOE]

    Presentation given by APEI Inc. at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about advanced low-cost SiC and GaN wide...

  16. Development of epitaxial AlxSc1-xN for artificially structured metal/semiconductor superlattice metamaterials

    SciTech Connect (OSTI)

    Sands, Timothy D.; Stach, Eric A.; Saha, Bivas; Saber, Sammy; Naik, Gururaj V.; Boltasseva, Alexandra; Kvam, Eric P.

    2015-02-01

    Epitaxial nitride rocksalt metal/semiconductor superlattices are emerging as a novel class of artificially structured materials that have generated significant interest in recent years for their potential application in plasmonic and thermoelectric devices. Though most nitride metals are rocksalt, nitride semiconductors in general have hexagonal crystal structure. We report rocksalt aluminum scandium nitride (Al,Sc)N alloys as the semiconducting component in epitaxial rocksalt metal/semiconductor superlattices. The AlxSc1-xN alloys when deposited directly on MgO substrates are stabilized in a homogeneous rocksalt (single) phase when x < 0.51. Employing 20 nm TiN as a seed layer on MgO substrates, the homogeneity range for stabilizing the rocksalt phase has been extended to x < 0.82 for a 120 nm film. The rocksalt AlxSc1-xN alloys show moderate direct bandgap bowing with a bowing parameter, B = 1.41 0.19 eV. The direct bandgap of metastable rocksalt AlN is extrapolated to be 4.70 0.20 eV. The tunable lattice parameter, bandgap, dielectric permittivity, and electronic properties of rocksalt AlxSc1-xN alloys enable high quality epitaxial rocksalt metal/AlxSc1-xN superlattices with a wide range of accessible metamaterials properties.

  17. Development of epitaxial AlxSc1-xN for artificially structured metal/semiconductor superlattice metamaterials

    SciTech Connect (OSTI)

    Sands, Timothy D.; Stach, Eric A.; Saha, Bivas; Saber, Sammy; Naik, Gururaj V.; Boltasseva, Alexandra; Kvam, Eric P.

    2015-02-01

    Epitaxial nitride rocksalt metal/semiconductor superlattices are emerging as a novel class of artificially structured materials that have generated significant interest in recent years for their potential application in plasmonic and thermoelectric devices. Though most nitride metals are rocksalt, nitride semiconductors in general have hexagonal crystal structure. We report rocksalt aluminum scandium nitride (Al,Sc)N alloys as the semiconducting component in epitaxial rocksalt metal/semiconductor superlattices. The AlxSc1-xN alloys when deposited directly on MgO substrates are stabilized in a homogeneous rocksalt (single) phase when x < 0.51. Employing 20 nm TiN as a seed layer on MgO substrates, the homogeneity range for stabilizing the rocksalt phase has been extended to x < 0.82 for a 120 nm film. The rocksalt AlxSc1-xN alloys show moderate direct bandgap bowing with a bowing parameter, B = 1.41 ± 0.19 eV. The direct bandgap of metastable rocksalt AlN is extrapolated to be 4.70 ± 0.20 eV. The tunable lattice parameter, bandgap, dielectric permittivity, and electronic properties of rocksalt AlxSc1-xN alloys enable high quality epitaxial rocksalt metal/AlxSc1-xN superlattices with a wide range of accessible metamaterials properties.

  18. Bandgap Engineering Inc | Open Energy Information

    Open Energy Info (EERE)

    Inc specializes in developing photovoltaic (PV) cells that combine silicon with nanotechnology to create high-efficiency cells at low cost 2. Bandgap Engineering Inc currently...

  19. DOE Traineeship In Power Engineering (Leveraging Wide Bandgap...

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

    design and manufacturing. The first part of the planned program announced today, which will create the traineeship, administration capability and provide support for curriculum ...

  20. AMO's New Institute Focused on Wide Bandgap Power Electronics Manufacturing

    Broader source: Energy.gov [DOE]

    The Next Generation Power Electronics National Manufacturing Institute announced by President Obama today will use $70 million provided by the U.S. Department of Energy's Advanced Manufacturing Office to support and manage its programs over the next five years.

  1. Pump-probe surface photovoltage spectroscopy measurements on semiconductor epitaxial layers

    SciTech Connect (OSTI)

    Jana, Dipankar Porwal, S.; Sharma, T. K. Oak, S. M.; Kumar, Shailendra

    2014-04-15

    Pump-probe Surface Photovoltage Spectroscopy (SPS) measurements are performed on semiconductor epitaxial layers. Here, an additional sub-bandgap cw pump laser beam is used in a conventional chopped light geometry SPS setup under the pump-probe configuration. The main role of pump laser beam is to saturate the sub-bandgap localized states whose contribution otherwise swamp the information related to the bandgap of material. It also affects the magnitude of Dember voltage in case of semi-insulating (SI) semiconductor substrates. Pump-probe SPS technique enables an accurate determination of the bandgap of semiconductor epitaxial layers even under the strong influence of localized sub-bandgap states. The pump beam is found to be very effective in suppressing the effect of surface/interface and bulk trap states. The overall magnitude of SPV signal is decided by the dependence of charge separation mechanisms on the intensity of the pump beam. On the contrary, an above bandgap cw pump laser can be used to distinguish the signatures of sub-bandgap states by suppressing the band edge related feature. Usefulness of the pump-probe SPS technique is established by unambiguously determining the bandgap of p-GaAs epitaxial layers grown on SI-GaAs substrates, SI-InP wafers, and p-GaN epilayers grown on Sapphire substrates.

  2. How Bilayer Graphene Got a Bandgap

    ScienceCinema (OSTI)

    Wang, Feng

    2013-05-29

    Graphene is the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But theres a catch: graphene has no bandgap. Now Feng Wang and his colleagues at Berkeley Lab and UC Berkeley have engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 milli-electron volts, which is the energy of infrared radiation.

  3. How Bilayer Graphene Got a Bandgap

    ScienceCinema (OSTI)

    Feng Wang

    2010-01-08

    Graphene is the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But theres a catch: graphene has no bandgap. Now Feng Wang and his colleagues at Berkeley Lab and UC Berkeley have engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 milli-electron volts, which is the energy of infrared radiation.

  4. Unipolar resistive switching in metal oxide/organic semiconductor non-volatile memories as a critical phenomenon

    SciTech Connect (OSTI)

    Bory, Benjamin F.; Meskers, Stefan C. J.; Rocha, Paulo R. F.; Gomes, Henrique L.; Leeuw, Dago M. de

    2015-11-28

    Diodes incorporating a bilayer of an organic semiconductor and a wide bandgap metal oxide can show unipolar, non-volatile memory behavior after electroforming. The prolonged bias voltage stress induces defects in the metal oxide with an areal density exceeding 10{sup 17 }m{sup −2}. We explain the electrical bistability by the coexistence of two thermodynamically stable phases at the interface between an organic semiconductor and metal oxide. One phase contains mainly ionized defects and has a low work function, while the other phase has mainly neutral defects and a high work function. In the diodes, domains of the phase with a low work function constitute current filaments. The phase composition and critical temperature are derived from a 2D Ising model as a function of chemical potential. The model predicts filamentary conduction exhibiting a negative differential resistance and nonvolatile memory behavior. The model is expected to be generally applicable to any bilayer system that shows unipolar resistive switching.

  5. GaTe semiconductor for radiation detection

    DOE Patents [OSTI]

    Payne, Stephen A.; Burger, Arnold; Mandal, Krishna C.

    2009-06-23

    GaTe semiconductor is used as a room-temperature radiation detector. GaTe has useful properties for radiation detectors: ideal bandgap, favorable mobilities, low melting point (no evaporation), non-hygroscopic nature, and availability of high-purity starting materials. The detector can be used, e.g., for detection of illicit nuclear weapons and radiological dispersed devices at ports of entry, in cities, and off shore and for determination of medical isotopes present in a patient.

  6. Machine learning bandgaps of double perovskites

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

    Pilania, G.; Mannodi-Kanakkithodi, A.; Uberuaga, B. P.; Ramprasad, R.; Gubernatis, J. E.; Lookman, T.

    2016-01-19

    The ability to make rapid and accurate predictions on bandgaps of double perovskites is of much practical interest for a range of applications. While quantum mechanical computations for high-fidelity bandgaps are enormously computation-time intensive and thus impractical in high throughput studies, informatics-based statistical learning approaches can be a promising alternative. Here we demonstrate a systematic feature-engineering approach and a robust learning framework for efficient and accurate predictions of electronic bandgaps of double perovskites. After evaluating a set of more than 1.2 million features, we identify lowest occupied Kohn-Sham levels and elemental electronegativities of the constituent atomic species as the mostmore » crucial and relevant predictors. As a result, the developed models are validated and tested using the best practices of data science and further analyzed to rationalize their prediction performance.« less

  7. Microfabricated bulk wave acoustic bandgap device

    DOE Patents [OSTI]

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, legal representative, Carol

    2010-11-23

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  8. Microfabricated bulk wave acoustic bandgap device

    DOE Patents [OSTI]

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, Carol

    2010-06-08

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  9. Semiconductor Revolution

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

    Energy Frontier Research Centers: Solid-State Lighting Science Center for Frontiers of ... Semiconductor Revolution HomeEnergy ResearchEFRCsSolid-State Lighting Science EFRC...

  10. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  11. Wide Area Thermal Processing of Light Emitting Materials

    SciTech Connect (OSTI)

    Duty, Chad E; Joshi, Pooran C; Jellison Jr, Gerald Earle; Angelini, Joseph Attilio; Sabau, Adrian S

    2011-10-01

    Laboratory laser materials synthesis of wide bandgap materials has been successfully used to create white light emitting materials (LEMs). This technology development has progressed to the exploration on design and construction of apparatus for wide area doping and phase transformation of wide bandgap material substrates. The objective of this proposal is to develop concepts for wide area doping and phase transformation based on AppliCote Associates, LLC laser technology and ORNL high density pulsed plasma arc technology.

  12. Freescale Semiconductor Successfully Implements an Energy Management...

    Energy Savers [EERE]

    This case study describes how Freescale Semiconductor implemented projects at its Oak Hill Fab plant in Austin, Texas, that reduced annual plant-wide energy consumption by 28 ...

  13. Monolithic, multi-bandgap, tandem, ultra-thin, strain-counterbalanced, photovoltaic energy converters with optimal subcell bandgaps

    DOE Patents [OSTI]

    Wanlass, Mark W.; Mascarenhas, Angelo

    2012-05-08

    Modeling a monolithic, multi-bandgap, tandem, solar photovoltaic converter or thermophotovoltaic converter by constraining the bandgap value for the bottom subcell to no less than a particular value produces an optimum combination of subcell bandgaps that provide theoretical energy conversion efficiencies nearly as good as unconstrained maximum theoretical conversion efficiency models, but which are more conducive to actual fabrication to achieve such conversion efficiencies than unconstrained model optimum bandgap combinations. Achieving such constrained or unconstrained optimum bandgap combinations includes growth of a graded layer transition from larger lattice constant on the parent substrate to a smaller lattice constant to accommodate higher bandgap upper subcells and at least one graded layer that transitions back to a larger lattice constant to accommodate lower bandgap lower subcells and to counter-strain the epistructure to mitigate epistructure bowing.

  14. Electron gas grid semiconductor radiation detectors

    DOE Patents [OSTI]

    Lee, Edwin Y.; James, Ralph B.

    2002-01-01

    An electron gas grid semiconductor radiation detector (EGGSRAD) useful for gamma-ray and x-ray spectrometers and imaging systems is described. The radiation detector employs doping of the semiconductor and variation of the semiconductor detector material to form a two-dimensional electron gas, and to allow transistor action within the detector. This radiation detector provides superior energy resolution and radiation detection sensitivity over the conventional semiconductor radiation detector and the "electron-only" semiconductor radiation detectors which utilize a grid electrode near the anode. In a first embodiment, the EGGSRAD incorporates delta-doped layers adjacent the anode which produce an internal free electron grid well to which an external grid electrode can be attached. In a second embodiment, a quantum well is formed between two of the delta-doped layers, and the quantum well forms the internal free electron gas grid to which an external grid electrode can be attached. Two other embodiments which are similar to the first and second embodiment involve a graded bandgap formed by changing the composition of the semiconductor material near the first and last of the delta-doped layers to increase or decrease the conduction band energy adjacent to the delta-doped layers.

  15. Development of Spintronic Bandgap Materials (Technical Report) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Development of Spintronic Bandgap Materials Citation Details In-Document Search Title: Development of Spintronic Bandgap Materials The development of Ge/Si quantum dots with high spatial precision has been pursued, with the goal of developing a platform for "spintronics bandgap materials". Quantum dots assemblies were grown by molecular beam epitaxy on carbon-templated silicon substrates. These structures were characterized by atomic force microscopy. Vertically gated

  16. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    SciTech Connect (OSTI)

    Black, Marcie

    2014-10-30

    This project aimed to demonstrate increased electronic coupling in silicon nanostructures relative to bulk silicon for the purpose of making high efficiency intermediate bandgap solar cells using silicon. To this end, we formed nanowires with controlled crystallographic orientation, small diameter, <111> sidewall faceting, and passivated surfaces to modify the electronic band structure in silicon by breaking down the symmetry of the crystal lattice. We grew and tested these silicon nanowires with <110>-growth axes, which is an orientation that should produce the coupling enhancement.

  17. High-efficiency, monolithic, multi-bandgap, tandem photovoltaic...

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

    Tidal Industrial Technologies Solar Photovoltaic Solar Thermal Startup America Vehicles ... High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters United ...

  18. Semiconductor Revolution

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

    Semiconductor Revolution - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced

  19. Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys

    SciTech Connect (OSTI)

    Uddin, M. R.; Doan, T. C.; Li, J.; Lin, J. Y.; Jiang, H. X.; Ziemer, K. S.

    2014-08-15

    The layer structured hexagonal boron nitride carbon semiconductor alloys, h-(BN)C, offer the unique abilities of bandgap engineering (from 0 for graphite to ∼6.4 eV for h-BN) and electrical conductivity control (from semi-metal for graphite to insulator for undoped h-BN) through alloying and have the potential to complement III-nitride wide bandgap semiconductors and carbon based nanostructured materials. Epilayers of (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys were synthesized by metal-organic chemical vapor deposition (MOCVD) on (0001) sapphire substrates. Hall-effect measurements revealed that homogeneous (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys are naturally n-type. For alloys with x = 0.032, an electron mobility of about 20 cm{sup 2}/Vs at 650 °K was measured. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical composition and analyze chemical bonding states. Both composition and chemical bonding analysis confirm the formation of alloys. XPS results indicate that the carbon concentration in the alloys increases almost linearly with the flow rate of the carbon precursor (propane (C{sub 3}H{sub 8})) employed during the epilayer growth. XPS chemical bonding analysis showed that these MOCVD grown alloys possess more C-N bonds than C-B bonds, which possibly renders the undoped h-(BN){sub 1-x}(C{sub 2}){sub x} alloys n-type and corroborates the Hall-effect measurement results.

  20. Molecular beam epitaxial growth and characterization of Bi{sub 2}Se{sub 3}/II-VI semiconductor heterostructures

    SciTech Connect (OSTI)

    Chen, Zhiyi Zhao, Lukas; Krusin-Elbaum, Lia; Garcia, Thor Axtmann; Tamargo, Maria C.; Hernandez-Mainet, Luis C.; Deng, Haiming

    2014-12-15

    Surfaces of three-dimensional topological insulators (TIs) have been proposed to host quantum phases at the interfaces with other types of materials, provided that the topological properties of interfacial regions remain unperturbed. Here, we report on the molecular beam epitaxy growth of II-VI semiconductorTI heterostructures using c-plane sapphire substrates. Our studies demonstrate that Zn{sub 0.49}Cd{sub 0.51}Se and Zn{sub 0.23}Cd{sub 0.25}Mg{sub 0.52}Se layers have improved quality relative to ZnSe. The structures exhibit a large relative upward shift of the TI bulk quantum levels when the TI layers are very thin (?6nm), consistent with quantum confinement imposed by the wide bandgap II-VI layers. Our transport measurements show that the characteristic topological signatures of the Bi{sub 2}Se{sub 3} layers are preserved.

  1. Light sources based on semiconductor current filaments

    DOE Patents [OSTI]

    Zutavern, Fred J.; Loubriel, Guillermo M.; Buttram, Malcolm T.; Mar, Alan; Helgeson, Wesley D.; O'Malley, Martin W.; Hjalmarson, Harold P.; Baca, Albert G.; Chow, Weng W.; Vawter, G. Allen

    2003-01-01

    The present invention provides a new type of semiconductor light source that can produce a high peak power output and is not injection, e-beam, or optically pumped. The present invention is capable of producing high quality coherent or incoherent optical emission. The present invention is based on current filaments, unlike conventional semiconductor lasers that are based on p-n junctions. The present invention provides a light source formed by an electron-hole plasma inside a current filament. The electron-hole plasma can be several hundred microns in diameter and several centimeters long. A current filament can be initiated optically or with an e-beam, but can be pumped electrically across a large insulating region. A current filament can be produced in high gain photoconductive semiconductor switches. The light source provided by the present invention has a potentially large volume and therefore a potentially large energy per pulse or peak power available from a single (coherent) semiconductor laser. Like other semiconductor lasers, these light sources will emit radiation at the wavelength near the bandgap energy (for GaAs 875 nm or near infra red). Immediate potential applications of the present invention include high energy, short pulse, compact, low cost lasers and other incoherent light sources.

  2. Extracting hot carriers from photoexcited semiconductor nanocrystals

    SciTech Connect (OSTI)

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  3. Quantum-size-controlled photoelectrochemical etching of semiconductor nanostructures

    DOE Patents [OSTI]

    Fischer, Arthur J.; Tsao, Jeffrey Y.; Wierer, Jr., Jonathan J.; Xiao, Xiaoyin; Wang, George T.

    2016-03-01

    Quantum-size-controlled photoelectrochemical (QSC-PEC) etching provides a new route to the precision fabrication of epitaxial semiconductor nanostructures in the sub-10-nm size regime. For example, quantum dots (QDs) can be QSC-PEC-etched from epitaxial InGaN thin films using narrowband laser photoexcitation, and the QD sizes (and hence bandgaps and photoluminescence wavelengths) are determined by the photoexcitation wavelength.

  4. Electrically dependent bandgaps in graphene on hexagonal boron nitride

    SciTech Connect (OSTI)

    Kaplan, D. Swaminathan, V.; Recine, G.

    2014-03-31

    We present first-principles calculations on the bandgap of graphene on a layer of hexagonal boron nitride in three different stacking configurations. Relative stability of the configurations is identified and bandgap tunability is demonstrated through the application of an external, perpendicularly applied electric field. We carefully examine the bandgap's sensitivity to both magnitude of the applied field as well as separation between the graphene and hexagonal boron nitride layers. Features of the band structure are examined and configuration-dependent relationships between the field and bandgap are revealed and elucidated through the atom-projected density of states. These findings suggest the potential for opening and modulating a bandgap in graphene as high as several hundred meV.

  5. Stretchable semiconductor elements and stretchable electrical circuits

    DOE Patents [OSTI]

    Rogers, John A.; Khang, Dahl-Young; Menard, Etienne

    2009-07-07

    The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

  6. New Class of Multi-Bandgap High-Efficiency Photovoltaics Enabled...

    Office of Scientific and Technical Information (OSTI)

    New Class of Multi-Bandgap High-Efficiency Photovoltaics Enabled by Broadband Diffractive Optics Citation Details In-Document Search Title: New Class of Multi-Bandgap ...

  7. Spectroscopic determination of the bandgap crossover composition in MBE-grown AlxGa1-xAs

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

    Fluegel, Brian; Alberi, Kirstin; Reno, John; Mascarenhas, Angelo

    2015-03-12

    The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the Γ and X conduction bands are measured at 1.7 K in the semiconductor alloy AlxGa1-xAs. The composition at which the bands cross is determined from photoluminescence of molecular-beam epitaxy samples grown very close to crossover. The use of resonant laser excitation and the improved sample linewidth allows precise determination of the bound exciton transition energies. Moreover, photoluminescence excitation spectroscopy is used to measure the binding energies of the donor-bound excitons and the Γ free exciton binding energy.

  8. Metallic photonic band-gap materials

    SciTech Connect (OSTI)

    Sigalas, M.M.; Chan, C.T.; Ho, K.M.; Soukoulis, C.M.

    1995-10-15

    We calculate the transmission and absorption of electromagnetic waves propagating in two-dimensional (2D) and 3D periodic metallic photonic band-gap (PBG) structures. For 2D systems, there is substantial difference between the {ital s}- and {ital p}-polarized waves. The {ital p}-polarized waves exhibit behavior similar to the dielectric PBG`s. But, the {ital s}-polarized waves have a cutoff frequency below which there are no propagating modes. For 3D systems, the results are qualitatively the same for both polarizations but there are important differences related to the topology of the structure. For 3D structures with isolated metallic scatterers (cermet topology), the behavior is similar to that of the dielectric PBG`s, while for 3D structures with the metal forming a continuous network (network topology), there is a cutoff frequency below which there are no propagating modes. The systems with the network topology may have some interesting applications for frequencies less than about 1 THz where the absorption can be neglected. We also study the role of the defects in the metallic structures.

  9. Optical Properties of InGaAsN: A New 1eV Bandgap Material System

    SciTech Connect (OSTI)

    Allerman, A.A.; Fritz, I.J.; Jones, E.D.; Kurtz, S.R.; Modine, N.A.; Tozer, S.T.; Wei, X.; Wright, A.F.

    1999-01-25

    InGaAsN is a new semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the bandgap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low temperature photohnninescence energy of the material for pressures between ambient and 110 kbar. We describe a simple, density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low concentration alloys. The theoretically predicted pressure dependence of the bandgap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for the strongly non-linear pressure dependence of the bandgap that, surprisingly, does not involve a nitrogen impurity band. Addhionally, conduction-band mass measurements, measured by three different techniques, will be described and finally, the magnetoluminescence determined pressure coefficient for the conduction-band mass is measured.

  10. Wafer-fused semiconductor radiation detector

    DOE Patents [OSTI]

    Lee, Edwin Y.; James, Ralph B.

    2002-01-01

    Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

  11. Photoelectrochemistry, Electronic Structure, and Bandgap Sizes of Semiconducting Cu(I)-Niobates and Cu(I)-Tantalates

    SciTech Connect (OSTI)

    Maggard, Paul A.

    2013-11-14

    Semiconducting metal-oxides have remained of intense research interest owing to their potential for achieving efficient solar-driven photocatalytic reactions in aqueous solutions that occur as a result of their bandgap excitation. The photocatalytic reduction of water or carbon dioxide to generate hydrogen or hydrocarbon fuels, respectively, can be driven on p-type (photocathodic) electrodes with suitable band energies. However, metal-oxide semiconductors are typically difficult to dope as p-type with a high mobility of carriers. The supported research led to the discovery of new p-type Cu(I)-niobate and Cu(I)-tantalate film electrodes that can be prepared on FTO glass. New high-purity flux syntheses and the full structural determination of several Cu(I)-containing niobates and tantalates have been completed, as well as new investigations of their optical and photoelectrochemical properties and electronic structures via density-functional theory calculations. For example, CuNbO3, Cu5Ta11O30 and CuNb3O8 were prepared in high purity and their structures were characterized by both single-crystal and powder X-ray diffraction techniques. These two classes of Cu(I)-containing compounds exhibit optical bandgap sizes ranging from ~1.3 eV to ~2.6 eV. Photoelectrochemical measurements of these compounds show strong photon-driven cathodic currents that confirm the p-type semiconductor behavior of CuNbO3, CuNb3O8, and Cu5Ta11O30. Incident-photon-to-current efficiencies are measured that approach greater than ~1%. Electronic-structure calculations based on density functional theory reveal the visible-light absorption stems from a nearly-direct bandgap transition involving a copper-to-niobium or tantalum (d10 to d0) charge-transfer excitations.

  12. Wavelength-resonant surface-emitting semiconductor laser

    DOE Patents [OSTI]

    Brueck, Steven R. J.; Schaus, Christian F.; Osinski, Marek A.; McInerney, John G.; Raja, M. Yasin A.; Brennan, Thomas M.; Hammons, Burrell E.

    1989-01-01

    A wavelength resonant semiconductor gain medium is disclosed. The essential feature of this medium is a multiplicity of quantum-well gain regions separated by semiconductor spacer regions of higher bandgap. Each period of this medium consisting of one quantum-well region and the adjacent spacer region is chosen such that the total width is equal to an integral multiple of 1/2 the wavelength in the medium of the radiation with which the medium is interacting. Optical, electron-beam and electrical injection pumping of the medium is disclosed. This medium may be used as a laser medium for single devices or arrays either with or without reflectors, which may be either semiconductor or external.

  13. Electron states in semiconductor quantum dots

    SciTech Connect (OSTI)

    Dhayal, Suman S.; Ramaniah, Lavanya M.; Ruda, Harry E.; Nair, Selvakumar V.

    2014-11-28

    In this work, the electronic structures of quantum dots (QDs) of nine direct band gap semiconductor materials belonging to the group II-VI and III-V families are investigated, within the empirical tight-binding framework, in the effective bond orbital model. This methodology is shown to accurately describe these systems, yielding, at the same time, qualitative insights into their electronic properties. Various features of the bulk band structure such as band-gaps, band curvature, and band widths around symmetry points affect the quantum confinement of electrons and holes. These effects are identified and quantified. A comparison with experimental data yields good agreement with the calculations. These theoretical results would help quantify the optical response of QDs of these materials and provide useful input for applications.

  14. Methods of producing free-standing semiconductors using sacrificial buffer layers and recyclable substrates

    DOE Patents [OSTI]

    Ptak, Aaron Joseph; Lin, Yong; Norman, Andrew; Alberi, Kirstin

    2015-05-26

    A method of producing semiconductor materials and devices that incorporate the semiconductor materials are provided. In particular, a method is provided of producing a semiconductor material, such as a III-V semiconductor, on a spinel substrate using a sacrificial buffer layer, and devices such as photovoltaic cells that incorporate the semiconductor materials. The sacrificial buffer material and semiconductor materials may be deposited using lattice-matching epitaxy or coincident site lattice-matching epitaxy, resulting in a close degree of lattice matching between the substrate material and deposited material for a wide variety of material compositions. The sacrificial buffer layer may be dissolved using an epitaxial liftoff technique in order to separate the semiconductor device from the spinel substrate, and the spinel substrate may be reused in the subsequent fabrication of other semiconductor devices. The low-defect density semiconductor materials produced using this method result in the enhanced performance of the semiconductor devices that incorporate the semiconductor materials.

  15. 2010 Defects in Semiconductors GRC

    SciTech Connect (OSTI)

    Shengbai Zhang

    2011-01-06

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, as well as an emphasis on the development of novel defect detection methods and first-principles defect theories. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference will deal with point and extended defects in a broad range of electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, oxides, sp{sup 2} carbon based-materials, and photovoltaic/solar cell materials, and in understanding important defect phenomena such as doping bottleneck in nanostructures and the diffusion of defects and impurities. The program consists of about twenty invited talks and a number of contributed poster sessions. The emphasis should be on work which has yet to be published. The large amount of discussion time provides an ideal forum for dealing with topics that are new and/or controversial.

  16. Photonic bandgap narrowing in conical hollow core Bragg fibers

    SciTech Connect (OSTI)

    Ozturk, Fahri Emre; Yildirim, Adem; Kanik, Mehmet; Bayindir, Mehmet

    2014-08-18

    We report the photonic bandgap engineering of Bragg fibers by controlling the thickness profile of the fiber during the thermal drawing. Conical hollow core Bragg fibers were produced by thermal drawing under a rapidly alternating load, which was applied by introducing steep changes to the fiber drawing speed. In conventional cylindrical Bragg fibers, light is guided by omnidirectional reflections from interior dielectric mirrors with a single quarter wave stack period. In conical fibers, the diameter reduction introduced a gradient of the quarter wave stack period along the length of the fiber. Therefore, the light guided within the fiber encountered slightly smaller dielectric layer thicknesses at each reflection, resulting in a progressive blueshift of the reflectance spectrum. As the reflectance spectrum shifts, longer wavelengths of the initial bandgap cease to be omnidirectionally reflected and exit through the cladding, which narrows the photonic bandgap. A narrow transmission bandwidth is particularly desirable in hollow waveguide mid-infrared sensing schemes, where broadband light is coupled to the fiber and the analyte vapor is introduced into the hollow core to measure infrared absorption. We carried out sensing simulations using the absorption spectrum of isopropyl alcohol vapor to demonstrate the importance of narrow bandgap fibers in chemical sensing applications.

  17. Unitary lens semiconductor device

    DOE Patents [OSTI]

    Lear, K.L.

    1997-05-27

    A unitary lens semiconductor device and method are disclosed. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors. 9 figs.

  18. Unitary lens semiconductor device

    DOE Patents [OSTI]

    Lear, Kevin L.

    1997-01-01

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  19. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Wednesday, 26 March 2008 00:00 Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome...

  20. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome...

  1. Spectroscopic determination of the bandgap crossover composition in MBE-grown AlxGa1-xAs

    SciTech Connect (OSTI)

    Fluegel, Brian; Alberi, Kirstin; Reno, John; Mascarenhas, Angelo

    2015-03-12

    The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the Γ and X conduction bands are measured at 1.7 K in the semiconductor alloy AlxGa1-xAs. The composition at which the bands cross is determined from photoluminescence of molecular-beam epitaxy samples grown very close to crossover. The use of resonant laser excitation and the improved sample linewidth allows precise determination of the bound exciton transition energies. Moreover, photoluminescence excitation spectroscopy is used to measure the binding energies of the donor-bound excitons and the Γ free exciton binding energy.

  2. Spectroscopic determination of the bandgap crossover composition in MBE-grown AlxGa1-xAs

    SciTech Connect (OSTI)

    Fluegel, Brian; Alberi, Kirstin; Reno, John; Mascarenhas, Angelo

    2015-03-12

    The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the ? and X conduction bands are measured at 1.7 K in the semiconductor alloy AlxGa1-xAs. The composition at which the bands cross is determined from photoluminescence of molecular-beam epitaxy samples grown very close to crossover. The use of resonant laser excitation and the improved sample linewidth allows precise determination of the bound exciton transition energies. Moreover, photoluminescence excitation spectroscopy is used to measure the binding energies of the donor-bound excitons and the ? free exciton binding energy.

  3. Methods and devices for fabricating and assembling printable semiconductor elements

    DOE Patents [OSTI]

    Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

    2009-11-24

    The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

  4. Methods and devices for fabricating and assembling printable semiconductor elements

    DOE Patents [OSTI]

    Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

    2011-07-19

    The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

  5. Methods and devices for fabricating and assembling printable semiconductor elements

    DOE Patents [OSTI]

    Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

    2014-03-04

    The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

  6. Methods and devices for fabricating and assembling printable semiconductor elements

    DOE Patents [OSTI]

    Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

    2013-05-14

    The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

  7. Freescale Semiconductor Successfully Implements an Energy Management System

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

    | Department of Energy Freescale Semiconductor Successfully Implements an Energy Management System Freescale Semiconductor Successfully Implements an Energy Management System This case study describes how Freescale Semiconductor implemented projects at its Oak Hill Fab plant in Austin, Texas, that reduced annual plant-wide energy consumption by 28 million kilowatt hours (kWh) of electricity and 26,000 million British thermal units (Btu) of natural gas between 2006 and 2009, saving more than

  8. Nanostructured and wide bandgap CdS:O thin films grown by reactive RF sputtering

    SciTech Connect (OSTI)

    Islam, M. A.; Rahman, K. S.; Haque, F.; Rashid, M. J.; Akhtaruzzaman, M.; Sopian, K.; Sulaiman, Y.; Amin, N.

    2015-05-15

    In this study, CdS:O thin films were prepared from a 99.999% CdS target by reactive sputtering in a Ar:O{sub 2} (99:1) ambient with different RF power at room temperature. The deposited films were studied by means of XRD, SEM, EDX, Hall Effect and UV-Vis spectrometry. The incorporations of O{sub 2} into the films were observed to increase with the decrease of deposition power. The cryatallinity of the films were reduced, whereas the band gaps of the films were increased by the increase of O{sub 2} content on the films. The films were found in nano-structured grains with a compact surface. It has been seen that the highest carrier density is observed in the film with O{sub 2} at.% 21.10, while the values decreased with the further increase or decrease of O{sub 2} content on the films; indicating that specific amount of donor like O{sub 2} atoms substitute to the S atoms can improve the carrier density of the CdS:O thin film.

  9. Bimodal wireless sensing with dual-channel wide bandgap heterostructure varactors

    SciTech Connect (OSTI)

    Deen, David A.; Osinsky, Andrei; Miller, Ross

    2014-03-03

    A capacitive wireless sensing scheme is developed that utilizes an AlN/GaN-based dual-channel varactor. The dual-channel heterostructure affords two capacitance plateaus within the capacitance-voltage (CV) characteristic, owing to the two parallel two-dimensional electron gases (2DEGs) located at respective AlN/GaN interfaces. The capacitance plateaus are leveraged for the definition of two resonant states of the sensor when implemented in an inductively-coupled resonant LRC network for wireless readout. The physics-based CV model is compared with published experimental results, which serve as a basis for the sensor embodiment. The bimodal resonant sensor is befitting for a broad application space ranging from gas, electrostatic, and piezoelectric sensors to biological and chemical detection.

  10. Optically induced transport through semiconductor-based molecular electronics

    SciTech Connect (OSTI)

    Li, Guangqi; Seideman, Tamar; Fainberg, Boris D.

    2015-04-21

    A tight binding model is used to investigate photoinduced tunneling current through a molecular bridge coupled to two semiconductor electrodes. A quantum master equation is developed within a non-Markovian theory based on second-order perturbation theory with respect to the molecule-semiconductor electrode coupling. The spectral functions are generated using a one dimensional alternating bond model, and the coupling between the molecule and the electrodes is expressed through a corresponding correlation function. Since the molecular bridge orbitals are inside the bandgap between the conduction and valence bands, charge carrier tunneling is inhibited in the dark. Subject to the dipole interaction with the laser field, virtual molecular states are generated via the absorption and emission of photons, and new tunneling channels open. Interesting phenomena arising from memory are noted. Such a phenomenon could serve as a switch.

  11. Semiconductor bridge (SCB) detonator

    DOE Patents [OSTI]

    Bickes, R.W. Jr.; Grubelich, M.C.

    1999-01-19

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

  12. Semiconductor bridge (SCB) detonator

    DOE Patents [OSTI]

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  13. Interconnected semiconductor devices

    DOE Patents [OSTI]

    Grimmer, Derrick P.; Paulson, Kenneth R.; Gilbert, James R.

    1990-10-23

    Semiconductor layer and conductive layer formed on a flexible substrate, divided into individual devices and interconnected with one another in series by interconnection layers and penetrating terminals.

  14. Thermophotovoltaic energy conversion using photonic bandgap selective emitters

    DOE Patents [OSTI]

    Gee, James M.; Lin, Shawn-Yu; Fleming, James G.; Moreno, James B.

    2003-06-24

    A method for thermophotovoltaic generation of electricity comprises heating a metallic photonic crystal to provide selective emission of radiation that is matched to the peak spectral response of a photovoltaic cell that converts the radiation to electricity. The use of a refractory metal, such as tungsten, for the photonic crystal enables high temperature operation for high radiant flux and high dielectric contrast for a full 3D photonic bandgap, preferable for efficient thermophotovoltaic energy conversion.

  15. Metal to semiconductor transition in metallic transition metal dichalcogenides

    SciTech Connect (OSTI)

    Li, Yan; Kang, Jun; Li, Jingbo; Tongay, Sefaattin; Wu, Junqiao; Yue, Qu

    2013-11-07

    We report on tuning the electronic and magnetic properties of metallic transition metal dichalcogenides (mTMDCs) by 2D to 1D size confinement. The stability of the mTMDC monolayers and nanoribbons is demonstrated by the larger binding energy compared to the experimentally available semiconducting TMDCs. The 2D MX{sub 2} (M?=?Nb, Ta; X?=?S, Se) monolayers are non-ferromagnetic metals and mechanically softer compared to their semiconducting TMDCs counterparts. Interestingly, mTMDCs undergo metal-to-semiconductor transition when the ribbon width approaches to ?13? and ?7? for zigzag and armchair edge terminations, respectively; then these ribbons convert back to metal when the ribbon widths further decrease. Zigzag terminated nanoribbons are ferromagnetic semiconductors, and their magnetic properties can also be tuned by hydrogen edge passivation, whereas the armchair nanoribbons are non-ferromagnetic semiconductors. Our results display that the mTMDCs offer a broad range of physical properties spanning from metallic to semiconducting and non-ferromagnetic to ferromagnetic that is ideal for applications where stable narrow bandgap semiconductors with different magnetic properties are desired.

  16. High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters

    DOE Patents [OSTI]

    Wanlass, Mark W.

    2011-11-29

    A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.

  17. High-efficiency, monolithic, multi-bandgap, tandem, photovoltaic energy converters

    DOE Patents [OSTI]

    Wanlass, Mark W

    2014-05-27

    A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.

  18. Silicon Carbide Semiconductors | GE Global Research

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

    Silicon Carbide Power Semiconductor Devices in the Cleanroom Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Silicon Carbide Power Semiconductor Devices in the Cleanroom Ron Olson 2012.10.04 I would like to introduce Zach Stum, the Wide Band Gap device engineer who is leading the "Next Generation SiC MOSFET"

  19. 15.09.28 RH Bandgap Tunability - JCAP

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

    Band Gap Tunability in Sb-Alloyed BiVO4 Quaternary Oxides as Visible-Light Absorbers for Solar Fuel Applications Loiudice, A. et al. Bandgap Tunability in Sb-Alloyed BiVO4 Quaternary Oxides as Visible Light Absorbers for Solar Fuel Applications. Advanced Materials, DOI: 10.1002/adma.201502361 (2015). Scientific Achievement A novel hotoanode material was discovered using a colloidal nanocrystal (NC ) -seeded growth, that is of general applicability for other complex oxides and thus may aid in

  20. High performance, high bandgap, lattice-mismatched, GaInP solar cells

    DOE Patents [OSTI]

    Wanlass, Mark W.; Carapella, Jeffrey J.; Steiner, Myles A.

    2014-07-08

    High performance, high bandgap, lattice-mismatched, photovoltaic cells (10), both transparent and non-transparent to sub-bandgap light, are provided as devices for use alone or in combination with other cells in split spectrum apparatus or other applications.

  1. Effect of Hydrogen Passivation on the Electronic Structure of Ionic Semiconductor Nanostructures

    SciTech Connect (OSTI)

    Deng, H. X.; Li, S. S.; Li, J. B.; Wei, S. H.

    2012-05-15

    In theoretical studies of thin film and nanostructured semiconductors, pseudohydrogen (PH) is widely used to passivate the surface dangling bonds. Based on these calculations, it is often believed that nanostructured semiconductors, due to quantum confinement, have a larger band gap than their bulk counterparts. Using first-principles band structure theory calculation and comparing systematically the differences between PH-passivated and real-hydrogen-passivated (RH-passivated) semiconductor surfaces and nanocrystals, we show that, unlike PH passivation that always increases the band gap with respect to the bulk value, RH passivation of the nanostructured semiconductors can either increase or decrease the band gap, depending on the ionicity of the nanocompounds. The differences between PH and RH passivations decreases when the covalency of the semiconductor increases and can be explained using a band coupling model. This observation greatly increases the tunability of nanostructured semiconductor properties, especially for wide-gap ionic semiconductors.

  2. Method of doping a semiconductor

    DOE Patents [OSTI]

    Yang, Chiang Y.; Rapp, Robert A.

    1983-01-01

    A method for doping semiconductor material. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient.

  3. Systematic approach for simultaneously correcting the band-gap...

    Office of Scientific and Technical Information (OSTI)

    simultaneously for a set of common cation binary semiconductors, such as III-V compounds, (Ga or In)X with X N,P,As,Sb, and II-VI compounds, (Zn or Cd)X, with X O,S,Se,Te. ...

  4. Zinc oxysulfide ternary alloy nanocrystals: A bandgap modulated photocatalyst

    SciTech Connect (OSTI)

    Pandey, Shiv K.; Nanotechnology Application Centre, University of Allahabad, Allahabad ; Pandey, Shipra; Pandey, Avinash C.; Mehrotra, G. K.

    2013-06-10

    Herein, we report a green economic route for the synthesis of a series of Zinc Oxysulfide (ZOS) (ZnO{sub 1-x}S{sub x}; 0 {<=} x {>=} 1; x = Sulfur) alloys nanoparticles. The crystallographic features of ZnO, ZOS, and ZnS confirmed by X-Ray Diffraction and validated by Transmission Electron Microscopy reveal the variation of lattice spacing in binary and ternary compositions with homogenous elemental distribution. The photocatalytic analysis of ZOS (0.4) is performed and compared with Degussa P25 to ascertain its photocatalytic activity against methyl orange under irradiation of 365 nm UV-Vis light. A bandgap of 2.7 eV for ZOS (0.4) aptly establishes its prospects for sunlight driven photocatalysis.

  5. Semiconductor Science and Technology

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

    lighting ReSeaRch & development at Sandia national laboRatoRieS The bridge to a new way of lighting the world ssls.sandia.gov Initiates decades-long investment into compound semiconductor science and technology, eventually establishing its Center for Compound Semiconductor Science and Technology 1 9 7 7 Begins investing in gallium nitride (GaN) materials, physics, and device capabilities 1 9 9 5 Launches its Grand Challenge Laboratory Directed Research and Development Project, "A

  6. Amorphous semiconductor solar cell

    DOE Patents [OSTI]

    Dalal, Vikram L.

    1981-01-01

    A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.

  7. Energy Department Awards $6 Million to Universities in Tennessee...

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

    cutting-edge wide bandgap semiconductors that can operate at higher temperatures, voltages, and frequencies, and are more durable and reliable than silicon-based counterparts. ...

  8. President Announces New Public-Private Manufacturing Innovation...

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

    a consortium of leading companies that includes some of the world's leading wide-bandgap semiconductor manufacturers, leading materials providers, and critical end-users such as...

  9. Semiconductor radiation detector

    DOE Patents [OSTI]

    Patt, Bradley E.; Iwanczyk, Jan S.; Tull, Carolyn R.; Vilkelis, Gintas

    2002-01-01

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  10. Frederic Laquai Seminar: Photocurrent Generation in Low-Bandgap Polymer and

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

    Small Molecule Organic Solar Cells | Center for Energy Efficient Materials Frederic Laquai Seminar: Photocurrent Generation in Low-Bandgap Polymer and Small Molecule Organic Solar Cells Apr 18, 2014 | 3:30 PM - 4:30 PM Frederic Laquai Head, Max Planck Research Group for Organic Optoelectronics Max Planck Institute for Polymer Research Photocurrent Generation in Low-Bandgap Polymer and Small Molecule Organic Solar Cells April 18, 2014 | 3:30pm | Elings Hall (CNSI) 1605 Faculty host: Quyen

  11. Tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge

    SciTech Connect (OSTI)

    Inaoka, Takeshi Furukawa, Takuro; Toma, Ryo; Yanagisawa, Susumu

    2015-09-14

    By means of a hybrid density-functional method, we investigate the tensile-strain effect of inducing the indirect-to-direct band-gap transition and reducing the band-gap energy of Ge. We consider [001], [111], and [110] uniaxial tensility and (001), (111), and (110) biaxial tensility. Under the condition of no normal stress, we determine both normal compression and internal strain, namely, relative displacement of two atoms in the primitive unit cell, by minimizing the total energy. We identify those strain types which can induce the band-gap transition, and evaluate the critical strain coefficient where the gap transition occurs. Either normal compression or internal strain operates unfavorably to induce the gap transition, which raises the critical strain coefficient or even blocks the transition. We also examine how each type of tensile strain decreases the band-gap energy, depending on its orientation. Our analysis clearly shows that synergistic operation of strain orientation and band anisotropy has a great influence on the gap transition and the gap energy.

  12. Method of passivating semiconductor surfaces

    DOE Patents [OSTI]

    Wanlass, Mark W.

    1990-01-01

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  13. Method of passivating semiconductor surfaces

    DOE Patents [OSTI]

    Wanlass, M.W.

    1990-06-19

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  14. Intrinsic Semiconductor | Open Energy Information

    Open Energy Info (EERE)

    Intrinsic Semiconductor is a privately held emerging growth company focusing on materials and device technologies based on silicon carbide (SiC) and gallium nitride (GaN)...

  15. Layered semiconductor neutron detectors

    DOE Patents [OSTI]

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  16. Semiconductor devices incorporating multilayer interference regions

    DOE Patents [OSTI]

    Biefeld, R.M.; Drummond, T.J.; Gourley, P.L.; Zipperian, T.E.

    1987-08-31

    A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration. 8 figs.

  17. Semiconductor devices incorporating multilayer interference regions

    DOE Patents [OSTI]

    Biefeld, Robert M.; Drummond, Timothy J.; Gourley, Paul L.; Zipperian, Thomas E.

    1990-01-01

    A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration.

  18. Use of chemical-mechanical polishing for fabricating photonic bandgap structures

    DOE Patents [OSTI]

    Fleming, James G.; Lin, Shawn-Yu; Hetherington, Dale L.; Smith, Bradley K.

    1999-01-01

    A method is disclosed for fabricating a two- or three-dimensional photonic bandgap structure (also termed a photonic crystal, photonic lattice, or photonic dielectric structure). The method uses microelectronic integrated circuit (IC) processes to fabricate the photonic bandgap structure directly upon a silicon substrate. One or more layers of arrayed elements used to form the structure are deposited and patterned, with chemical-mechanical polishing being used to planarize each layer for uniformity and a precise vertical tolerancing of the layer. The use of chemical-mechanical planarization allows the photonic bandgap structure to be formed over a large area with a layer uniformity of about two-percent. Air-gap photonic bandgap structures can also be formed by removing a spacer material separating the arrayed elements by selective etching. The method is useful for fabricating photonic bandgap structures including Fabry-Perot resonators and optical filters for use at wavelengths in the range of about 0.2-20 .mu.m.

  19. Process for producing chalcogenide semiconductors

    DOE Patents [OSTI]

    Noufi, Rommel; Chen, Yih-Wen

    1987-01-01

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  20. Process for producing chalcogenide semiconductors

    DOE Patents [OSTI]

    Noufi, R.; Chen, Y.W.

    1985-04-30

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  1. Variable temperature semiconductor film deposition

    DOE Patents [OSTI]

    Li, Xiaonan; Sheldon, Peter

    1998-01-01

    A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  2. Variable temperature semiconductor film deposition

    DOE Patents [OSTI]

    Li, X.; Sheldon, P.

    1998-01-27

    A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  3. Semiconductor bridge, SCB, ignition of energetic materials

    SciTech Connect (OSTI)

    Bickes, R.W.; Grubelich, M.D.; Harris, S.M.; Merson, J.A.; Tarbell, W.W.

    1997-04-01

    Sandia National Laboratories` semiconductor bridge, SCB, is now being used for the ignition or initiation of a wide variety of exeoergic materials. Applications of this new technology arose because of a need at the system level to provide light weight, small volume and low energy explosive assemblies. Conventional bridgewire devices could not meet the stringent size, weight and energy requirements of our customers. We present an overview of SCB technology and the ignition characteristics for a number of energetic materials including primary and secondary explosives, pyrotechnics, thermites and intermetallics. We provide examples of systems designed to meet the modern requirements that sophisticated systems must satisfy in today`s market environments.

  4. Physics with isotopically controlled semiconductors

    SciTech Connect (OSTI)

    Haller, E. E.

    2010-07-15

    This paper is based on a tutorial presentation at the International Conference on Defects in Semiconductors (ICDS-25) held in Saint Petersburg, Russia in July 2009. The tutorial focused on a review of recent research involving isotopically controlled semiconductors. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, is the most prominent effect for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples.

  5. Dopant type and/or concentration selective dry photochemical etching of semiconductor materials

    DOE Patents [OSTI]

    Ashby, C.R.H.; Dishman, J.L.

    1985-10-11

    Disclosed is a method of selectively photochemically dry etching a first semiconductor material of a given composition in the presence of a second semiconductor material which is of a composition different from said first material, said second material substantially not being etched during said method. The method comprises subjecting both materials to the same photon flux of an energy greater than their respective direct bandgaps and to the same gaseous chemical etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said conditions also being such that the resultant electronic structure of the first semiconductor material under said photon flux is sufficient for the first material to undergo substantial photochemical etching under said conditions and being such that the resultant electronic structure of the second semiconductor material under said photon flux is not sufficient for the second material to undergo substantial photochemical etching under said conditions. In a preferred mode, the materials are subjected to a bias voltage which suppresses etching in n- or p-type material but not in p- or n-type material, respectively; or suppresses etching in the more heavily doped of two n-type or two p-type materials.

  6. Dopant type and/or concentration selective dry photochemical etching of semiconductor materials

    DOE Patents [OSTI]

    Ashby, Carol I. H.; Dishman, James L.

    1987-01-01

    A method of selectively photochemically dry etching a first semiconductor material of a given composition in the presence of a second semiconductor material which is of a composition different from said first material, said second material substantially not being etched during said method, comprises subjecting both materials to the same photon flux of an energy greater than their respective direct bandgaps and to the same gaseous chemical etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said conditions also being such that the resultant electronic structure of the first semiconductor material under said photon flux is sufficient for the first material to undergo substantial photochemical etching under said conditions and being such that the resultant electronic structure of the second semiconductor material under said photon flux is not sufficient for the second material to undergo substantial photochemical etching under said conditions. In a preferred mode, the materials are subjected to a bias voltage which suppresses etching in n- or p- type material but not in p- or n-type material, respectively; or suppresses etching in the more heavily doped of two n-type or two p-type materials.

  7. A Spintronic Semiconductor with Selectable Charge Carriers

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

    A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive ... Strategies for developing spintronic semiconductors have been based on surface doping or ...

  8. A Spintronic Semiconductor with Selectable Charge Carriers

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

    A Spintronic Semiconductor with Selectable Charge Carriers A Spintronic Semiconductor with Selectable Charge Carriers Print Wednesday, 28 August 2013 00:00 Accentuating the ...

  9. EMei Semiconductor Materials Plant Research Institute | Open...

    Open Energy Info (EERE)

    EMei Semiconductor Materials Plant Research Institute Jump to: navigation, search Name: EMei Semiconductor Materials Plant & Research Institute Place: Emei, Sichuan Province, China...

  10. Topsil Semiconductor Materials AS | Open Energy Information

    Open Energy Info (EERE)

    Topsil Semiconductor Materials AS Jump to: navigation, search Name: Topsil Semiconductor Materials AS Place: Frederikssund, Denmark Zip: 3600 Product: Danish specialist...

  11. Wide-bandgap high-mobility ZnO thin-film transistors produced at room temperature

    SciTech Connect (OSTI)

    Fortunato, Elvira M.C.; Barquinha, Pedro M.C.; Pimentel, Ana C.M.B.G.; Goncalves, Alexandra M.F.; Marques, Antonio J.S.; Martins, Rodrigo F.P.; Pereira, Luis M.N.

    2004-09-27

    We report high-performance ZnO thin-film transistor (ZnO-TFT) fabricated by rf magnetron sputtering at room temperature with a bottom gate configuration. The ZnO-TFT operates in the enhancement mode with a threshold voltage of 19 V, a saturation mobility of 27 cm{sup 2}/V s, a gate voltage swing of 1.39 V/decade and an on/off ratio of 3x10{sup 5}. The ZnO-TFT presents an average optical transmission (including the glass substrate) of 80% in the visible part of the spectrum. The combination of transparency, high mobility, and room-temperature processing makes the ZnO-TFT a very promising low-cost optoelectronic device for the next generation of invisible and flexible electronics.

  12. Semiconductor radiation detector

    SciTech Connect (OSTI)

    Bell, Zane W.; Burger, Arnold

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  13. Semiconductor Nanocrystals for Biological Imaging

    SciTech Connect (OSTI)

    Fu, Aihua; Gu, Weiwei; Larabell, Carolyn; Alivisatos, A. Paul

    2005-06-28

    Conventional organic fluorophores suffer from poor photo stability, narrow absorption spectra and broad emission feature. Semiconductor nanocrystals, on the other hand, are highly photo-stable with broad absorption spectra and narrow size-tunable emission spectra. Recent advances in the synthesis of these materials have resulted in bright, sensitive, extremely photo-stable and biocompatible semiconductor fluorophores. Commercial availability facilitates their application in a variety of unprecedented biological experiments, including multiplexed cellular imaging, long-term in vitro and in vivo labeling, deep tissue structure mapping and single particle investigation of dynamic cellular processes. Semiconductor nanocrystals are one of the first examples of nanotechnology enabling a new class of biomedical applications.

  14. Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material

    DOE Patents [OSTI]

    Sopori, Bhushan; Rangappan, Anikara

    2014-11-25

    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.

  15. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  16. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, B.L.

    1995-06-20

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

  17. Size Dependence of the Bandgap of Plasma Synthesized Silicon Nanoparticles Through Direct Introduction of Sulfur Hexafluoride

    SciTech Connect (OSTI)

    Theingi, S.; Guan, T. Y.; Kendrick, C.; Klafehn, G.; Gorman, B. P.; Taylor, P. C.; Lusk, M. T.; Stradins, Pauls; Collins, R. T.

    2015-10-19

    Developing silicon nanoparticle (SiNP) synthesis techniques that allow for straightforward control of nanoparticle size and associated optical properties is critical to potential applications of these materials. In addition, it is, in general, hard to probe the absorption threshold in these materials due to silicon's low absorption coefficient. In this study, size is controlled through direct introduction of sulfur hexafluoride (SF6) into the dilute silane precursor of plasma synthesized SiNPs. Size reduction by nearly a factor of two with high crystallinity independent of size is demonstrated. Optical absorption spectra of the SiNPs in the vicinity of the bandgap are measured using photothermal deflection spectroscopy. Bandgap as a function of size is extracted taking into account the polydispersity of the samples. A systematic blue shift inabsorption edge due to quantum confinement in the SiNPs is observed with increasing flow of SF6. Photoluminescence (PL) spectra show a similar blue shift with size. However, a ~300 meV difference in energy between emission and absorption for all sizes suggests that PL emission involves a defect related process. While PL may allow size-induced shifts in the bandgap of SiNPs to be monitored, it cannot be relied on to give an accurate value for the bandgap as a function of size.

  18. Controlling terahertz waves with meta-materials and photonic bandgap structures

    SciTech Connect (OSTI)

    Shchegolkov, Dmitry; Azad, Abul; O' Hara, John F; Moody, Nathan A; Simakov, Evgenya I

    2010-12-07

    We will describe research conducted at Los Alamos National Laboratory towards developing components for controlling terahertz waves. We employ meta-materials and, particularly, meta-films, as very compact absorbers for controlling quasioptical beams. We believe that dielectric photonic bandgap structures could replace ordinary metal waveguide devices at THz, since metal structures become extremely lossy in this frequency range.

  19. Hydrogen local vibrational modes in semiconductors

    SciTech Connect (OSTI)

    McCluskey, M D

    1997-06-01

    Following, a review of experimental techniques, theory, and previous work, the results of local vibrational mode (LVM) spectroscopy on hydrogen-related complexes in several different semiconductors are discussed. Hydrogen is introduced either by annealing in a hydrogen ambient. exposure to a hydrogen plasma, or during growth. The hydrogen passivates donors and acceptors in semiconductors, forming neutral complexes. When deuterium is substituted for hydrogen. the frequency of the LVM decreases by approximately the square root of two. By varying the temperature and pressure of the samples, the microscopic structures of hydrogen-related complexes are determined. For group II acceptor-hydrogen complexes in GaAs, InP, and GaP, hydrogen binds to the host anion in a bond-centered orientation, along the [111] direction, adjacent to the acceptor. The temperature dependent shift of the LVMs are proportional to the lattice thermal energy U(T), a consequence of anharmonic coupling between the LVM and acoustical phonons. In the wide band gap semiconductor ZnSe, epilayers grown by metalorganic chemical vapor phase epitaxy (MOCVD) and doped with As form As-H complexes. The hydrogen assumes a bond-centered orientation, adjacent to a host Zn. In AlSb, the DX centers Se and Te are passivated by hydrogen. The second, third, and fourth harmonics of the wag modes are observed. Although the Se-D complex has only one stretch mode, the Se-H stretch mode splits into three peaks. The anomalous splitting is explained by a new interaction between the stretch LVM and multi-phonon modes of the lattice. As the temperature or pressure is varied, and anti-crossing is observed between LVM and phonon modes.

  20. Design and Synthesis of Novel Diluted Magnetic Semiconductors...

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

    Design and Synthesis of Novel Diluted Magnetic Semiconductors Diluted magnetic semiconductors (DMSs) are semiconductors doped with small amounts of magnetic active transition...

  1. Bandgap widening in thermochromic Mg-doped VO{sub 2} thin films: Quantitative data based on optical absorption

    SciTech Connect (OSTI)

    Li, Shu-Yi; Niklasson, Gunnar A.; Granqvist, Claes G.; Mlyuka, Nuru R.; Department of Physics, University of Dar es Salaam, P.O. Box 35063, Dar es Salaam ; Primetzhofer, Daniel; Possnert, Gran; Halln, Anders

    2013-10-14

    Thermochromic Mg-doped VO{sub 2} films were deposited by reactive direct current magnetron sputtering onto heated glass and carbon substrates. Elemental compositions were inferred from Rutherford backscattering. Optical bandgaps were obtained from spectral transmittance and reflectance measurementsfrom both the film side and the back side of the samplesand ensuing determination of absorption coefficients. The bandgap of Mg-doped films was found to increase by 3.9 0.5 eV per unit of atom ratio Mg/(Mg + V) for 0 < Mg/(Mg + V) < 0.21. The presence of ?0.45 at. % Si enhanced the bandgap even more.

  2. Selenium semiconductor core optical fibers

    SciTech Connect (OSTI)

    Tang, G. W.; Qian, Q. Peng, K. L.; Wen, X.; Zhou, G. X.; Sun, M.; Chen, X. D.; Yang, Z. M.

    2015-02-15

    Phosphate glass-clad optical fibers containing selenium (Se) semiconductor core were fabricated using a molten core method. The cores were found to be amorphous as evidenced by X-ray diffraction and corroborated by Micro-Raman spectrum. Elemental analysis across the core/clad interface suggests that there is some diffusion of about 3 wt % oxygen in the core region. Phosphate glass-clad crystalline selenium core optical fibers were obtained by a postdrawing annealing process. A two-cm-long crystalline selenium semiconductor core optical fibers, electrically contacted to external circuitry through the fiber end facets, exhibit a three times change in conductivity between dark and illuminated states. Such crystalline selenium semiconductor core optical fibers have promising utility in optical switch and photoconductivity of optical fiber array.

  3. Controlling spin-dependent tunneling by bandgap tuning in epitaxial rocksalt MgZnO films

    SciTech Connect (OSTI)

    Li, D. L.; Ma, Q. L.; Wang, S. G.; Ward, R. C. C.; Hesjedal, T.; Zhang, X. -G.; Kohn, A.; Amsellem, E.; Yang, G.; Liu, J. L.; Jiang, J.; Wei, H. X.; Han, X. F.

    2014-12-02

    Widespread application of magnetic tunnel junctions (MTJs) for information storage has so far been limited by the complicated interplay between tunnel magnetoresistance (TMR) ratio and the product of resistance and junction area (RA). An intricate connection exists between TMR ratio, RA value and the bandgap and crystal structure of the barrier, a connection that must be unravelled to optimise device performance and enable further applications to be developed. In this paper, we demonstrate a novel method to tailor the bandgap of an ultrathin, epitaxial Zn-doped MgO tunnel barrier with rocksalt structure. This structure is attractive due to its good Δ1 spin filtering effect, and we show that MTJs based on tunable MgZnO barriers allow effective balancing of TMR ratio and RA value. Finally, in this way spin-dependent transport properties can be controlled, a key challenge for the development of spintronic devices.

  4. Controlling spin-dependent tunneling by bandgap tuning in epitaxial rocksalt MgZnO films

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

    Li, D. L.; Ma, Q. L.; Wang, S. G.; Ward, R. C. C.; Hesjedal, T.; Zhang, X. -G.; Kohn, A.; Amsellem, E.; Yang, G.; Liu, J. L.; et al

    2014-12-02

    Widespread application of magnetic tunnel junctions (MTJs) for information storage has so far been limited by the complicated interplay between tunnel magnetoresistance (TMR) ratio and the product of resistance and junction area (RA). An intricate connection exists between TMR ratio, RA value and the bandgap and crystal structure of the barrier, a connection that must be unravelled to optimise device performance and enable further applications to be developed. In this paper, we demonstrate a novel method to tailor the bandgap of an ultrathin, epitaxial Zn-doped MgO tunnel barrier with rocksalt structure. This structure is attractive due to its good Δ1more » spin filtering effect, and we show that MTJs based on tunable MgZnO barriers allow effective balancing of TMR ratio and RA value. Finally, in this way spin-dependent transport properties can be controlled, a key challenge for the development of spintronic devices.« less

  5. Controlled buckling structures in semiconductor interconnects and nanomembranes for stretchable electronics

    DOE Patents [OSTI]

    Rogers, John A.; Meitl, Matthew; Sun, Yugang; Ko, Heung Cho; Carlson, Andrew; Choi, Won Mook; Stoykovich, Mark; Jiang, Hanqing; Huang, Yonggang; Nuzzo, Ralph G.; Zhu, Zhengtao; Menard, Etienne; Khang, Dahl-Young

    2016-04-26

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

  6. Controlled buckling structures in semiconductor interconnects and nanomembranes for stretchable electronics

    DOE Patents [OSTI]

    Rogers, John A.; Meitl, Matthew; Sun, Yugang; Ko, Heung Cho; Carlson, Andrew; Choi, Won Mook; Stoykovich, Mark; Jiang, Hanqing; Huang, Yonggang; Nuzzo, Ralph G.; Lee, Keon Jae; Zhu, Zhengtao; Menard, Etienne; Khang, Dahl-Young; Kan, Seong Jun; Ahn, Jong Hyun; Kim, Hoon-sik

    2012-07-10

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

  7. Controlled buckling structures in semiconductor interconnects and nanomembranes for stretchable electronics

    DOE Patents [OSTI]

    Rogers, John A; Meitl, Matthew; Sun, Yugang; Ko, Heung Cho; Carlson, Andrew; Choi, Won Mook; Stoykovich, Mark; Jiang, Hanqing; Huang, Yonggang; Nuzzo, Ralph G; Zhu, Zhengtao; Menard, Etienne; Khang, Dahl-Young

    2014-05-20

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

  8. High Bandgap III-V Alloys for High Efficiency Optoelectronics - Energy

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

    Innovation Portal 130221326 Site Map Printable Version Share this resource About Search Categories (15) Advanced Materials Biomass and Biofuels Building Energy Efficiency Electricity Transmission Energy Analysis Energy Storage Geothermal Hydrogen and Fuel Cell Hydropower, Wave and Tidal Industrial Technologies Solar Photovoltaic Solar Thermal Startup America Vehicles and Fuels Wind Energy Partners (27) Visual Patent Search Success Stories Find More Like This Return to Search High Bandgap

  9. Method of preparing nitrogen containing semiconductor material

    DOE Patents [OSTI]

    Barber, Greg D.; Kurtz, Sarah R.

    2004-09-07

    A method of combining group III elements with group V elements that incorporates at least nitrogen from a nitrogen halide for use in semiconductors and in particular semiconductors in photovoltaic cells.

  10. Method and structure for passivating semiconductor material

    DOE Patents [OSTI]

    Pankove, Jacques I.

    1981-01-01

    A structure for passivating semiconductor material comprises a substrate of crystalline semiconductor material, a relatively thin film of carbon disposed on a surface of the crystalline material, and a layer of hydrogenated amorphous silicon deposited on the carbon film.

  11. Semiconductor nanocrystal-based phagokinetic tracking

    DOE Patents [OSTI]

    Alivisatos, A Paul; Larabell, Carolyn A; Parak, Wolfgang J; Le Gros, Mark; Boudreau, Rosanne

    2014-11-18

    Methods for determining metabolic properties of living cells through the uptake of semiconductor nanocrystals by cells. Generally the methods require a layer of neutral or hydrophilic semiconductor nanocrystals and a layer of cells seeded onto a culture surface and changes in the layer of semiconductor nanocrystals are detected. The observed changes made to the layer of semiconductor nanocrystals can be correlated to such metabolic properties as metastatic potential, cell motility or migration.

  12. Semiconductor Manufacturing International Corp SMIC | Open Energy...

    Open Energy Info (EERE)

    Manufacturing International Corp SMIC Jump to: navigation, search Name: Semiconductor Manufacturing International Corp (SMIC) Place: Shanghai, Shanghai Municipality, China Zip:...

  13. Semiconductor devices having a recessed electrode structure

    DOE Patents [OSTI]

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2015-05-26

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  14. Diode having trenches in a semiconductor region

    DOE Patents [OSTI]

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2016-03-22

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  15. Semiconductor electrode with improved photostability characteristics

    DOE Patents [OSTI]

    Frank, A.J.

    1985-02-19

    An electrode is described for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode consists of a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

  16. Semiconductor electrode with improved photostability characteristics

    DOE Patents [OSTI]

    Frank, Arthur J.

    1987-01-01

    An electrode is disclosed for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode includes a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

  17. Semiconductor assisted metal deposition for nanolithography applications

    SciTech Connect (OSTI)

    Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

    2001-01-01

    An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

  18. Semiconductor assisted metal deposition for nanolithography applications

    SciTech Connect (OSTI)

    Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

    2002-01-01

    An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

  19. Final Report: Bandgap-Engineered Thermophotovoltaic Devices for Hi Efficiency Radioisotope Power, July 9, 1996 - July 8, 1999

    SciTech Connect (OSTI)

    Sundaram, V; Morgan, M.D.; Horne, W.E.

    2000-03-15

    During Phase I the feasibility of fabricating high-performance, low bandgap (0.58ev)PV cells by thermally diffusing p-n junctions in GaSb based quaternary materials was established. During phase II, bandgap engineered thermophotovoltaic (TPV) cells were optimized, development of a low-cost build source material for quaternary devices was investigated, and a diesel-fueled, TPV test-bed was built and tested allowing its performance to be characterized.

  20. Semiconductor-based optical refrigerator

    DOE Patents [OSTI]

    Epstein, Richard I.; Edwards, Bradley C.; Sheik-Bahae, Mansoor

    2002-01-01

    Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

  1. Mechanical scriber for semiconductor devices

    DOE Patents [OSTI]

    Lin, P.T.

    1985-03-05

    A mechanical scriber using a scribing tip, such as a diamond, provides controlled scriber forces with a spring-loaded compound lever arrangement. The scribing force and range of scribing depth are adjusted by a pair of adjustable micrometer heads. A semiconductor device, such as a multilayer solar cell, can be formed into scribed strips at each layer. 5 figs.

  2. Mechanical scriber for semiconductor devices

    DOE Patents [OSTI]

    Lin, Peter T.

    1985-01-01

    A mechanical scriber using a scribing tip, such as a diamond, provides controlled scriber forces with a spring-loaded compound lever arrangement. The scribing force and range of scribing depth are adjusted by a pair of adjustable micrometer heads. A semiconductor device, such as a multilayer solar cell, can be formed into scribed strips at each layer.

  3. Semiconductor films on flexible iridium substrates

    DOE Patents [OSTI]

    Goyal, Amit

    2005-03-29

    A laminate semiconductor article includes a flexible substrate, an optional biaxially textured oxide buffer system on the flexible substrate, a biaxially textured Ir-based buffer layer on the substrate or the buffer system, and an epitaxial layer of a semiconductor. Ir can serve as a substrate with an epitaxial layer of a semiconductor thereon.

  4. Controlled growth of semiconductor crystals

    DOE Patents [OSTI]

    Bourret-Courchesne, E.D.

    1992-07-21

    A method is disclosed for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B[sub x]O[sub y] are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T[sub m1] of the oxide of boron (T[sub m1]=723 K for boron oxide B[sub 2]O[sub 3]), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T[sub m2] of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm[sup 2]. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide of boron in the crucible charge is melted, and the sum of thicknesses of the solid boron oxide layer and liquid boron oxide layer should be at least 50 [mu]m. 7 figs.

  5. Controlled growth of semiconductor crystals

    DOE Patents [OSTI]

    Bourret-Courchesne, Edith D.

    1992-01-01

    A method for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B.sub.x O.sub.y are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T.sub.m1 of the oxide of boron (T.sub.m1 =723.degree. K. for boron oxide B.sub.2 O.sub.3), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T.sub.m2 of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm.sup.2. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide of boron in the crucible charge is melted, and the sum of thicknesses of the solid boron oxide layer and liquid boron oxide layer should be at least 50 .mu.m.

  6. Back-side readout semiconductor photomultiplier

    DOE Patents [OSTI]

    Choong, Woon-Seng; Holland, Stephen E

    2014-05-20

    This disclosure provides systems, methods, and apparatus related to semiconductor photomultipliers. In one aspect, a device includes a p-type semiconductor substrate, the p-type semiconductor substrate having a first side and a second side, the first side of the p-type semiconductor substrate defining a recess, and the second side of the p-type semiconductor substrate being doped with n-type ions. A conductive material is disposed in the recess. A p-type epitaxial layer is disposed on the second side of the p-type semiconductor substrate. The p-type epitaxial layer includes a first region proximate the p-type semiconductor substrate, the first region being implanted with p-type ions at a higher doping level than the p-type epitaxial layer, and a second region disposed on the first region, the second region being doped with p-type ions at a higher doping level than the first region.

  7. Development of high-bandgap AlGaInP solar cells grown by organometallic vapor-phase epitaxy

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

    Perl, Emmett E.; Simon, John; Geisz, John F.; Olavarria, Waldo; Young, Michelle; Duda, Anna; Friedman, Daniel J.; Steiner, Myles A.

    2016-03-29

    AlGaInP solar cells with bandgaps between 1.9 and 2.2 eV are investigated for use in next-generation multijunction photovoltaic devices. This quaternary alloy is of great importance to the development of III-V solar cells with five or more junctions and for cells optimized for operation at elevated temperatures because of the high bandgaps required in these designs. In this work, we explore the conditions for the organometallic vapor-phase epitaxy growth of AlGaInP and study their effects on cell performance. Initial efforts focused on developing ~2.0-eV AlGaInP solar cells with a nominal aluminum composition of 12%. Under the direct spectrum at 1000more » W/m2 (AM1.5D), the best of these samples had an open-circuit voltage of 1.59 V, a bandgap-voltage offset of 440 mV, a fill factor of 88.0%, and an efficiency of 14.8%. We then varied the aluminum composition of the alloy from 0% to 24% and were able to tune the bandgap of the AlGaInP layers from ~1.9 to ~2.2 eV. Furthermore, while the samples with a higher aluminum composition exhibited a reduced quantum efficiency and increased bandgap-voltage offset, the bandgap-voltage offset remained at 500 mV or less, up to a bandgap of ~2.1 eV.« less

  8. Compound semiconductor optical waveguide switch

    DOE Patents [OSTI]

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  9. Etching Of Semiconductor Wafer Edges

    DOE Patents [OSTI]

    Kardauskas, Michael J. (Billerica, MA); Piwczyk, Bernhard P. (Dunbarton, NH)

    2003-12-09

    A novel method of etching a plurality of semiconductor wafers is provided which comprises assembling said plurality of wafers in a stack, and subjecting said stack of wafers to dry etching using a relatively high density plasma which is produced at atmospheric pressure. The plasma is focused magnetically and said stack is rotated so as to expose successive edge portions of said wafers to said plasma.

  10. Semiconductor Quantum Rods as Single Molecule FluorescentBiological Labels

    SciTech Connect (OSTI)

    Fu, Aihua; Gu, Weiwei; Boussert, Benjamine; Koski, Kristie; Gerion, Daniele; Manna, Liberato; Le Gros, Mark; Larabell, Carolyn; Alivisatos, A. Paul

    2006-05-29

    In recent years, semiconductor quantum dots have beenapplied with great advantage in a wide range of biological imagingapplications. The continuing developments in the synthesis of nanoscalematerials and specifically in the area of colloidal semiconductornanocrystals have created an opportunity to generate a next generation ofbiological labels with complementary or in some cases enhanced propertiescompared to colloidal quantum dots. In this paper, we report thedevelopment of rod shaped semiconductor nanocrystals (quantum rods) asnew fluorescent biological labels. We have engineered biocompatiblequantum rods by surface silanization and have applied them fornon-specific cell tracking as well as specific cellular targeting. Theproperties of quantum rods as demonstrated here are enhanced sensitivityand greater resistance for degradation as compared to quantum dots.Quantum rods have many potential applications as biological labels insituations where their properties offer advantages over quantumdots.

  11. Multi-phonon-assisted absorption and emission in semiconductors and its potential for laser refrigeration

    SciTech Connect (OSTI)

    Khurgin, Jacob B.

    2014-06-02

    Laser cooling of semiconductors has been an elusive goal for many years, and while attempts to cool the narrow gap semiconductors such as GaAs are yet to succeed, recently, net cooling has been attained in a wider gap CdS. This raises the question of whether wider gap semiconductors with higher phonon energies and stronger electron-phonon coupling are better suitable for laser cooling. In this work, we develop a straightforward theory of phonon-assisted absorption and photoluminescence of semiconductors that involves more than one phonon and use to examine wide gap materials, such as GaN and CdS and compare them with GaAs. The results indicate that while strong electron-phonon coupling in both GaN and CdS definitely improves the prospects of laser cooling, large phonon energy in GaN may be a limitation, which makes CdS a better prospect for laser cooling.

  12. Optical Furnace offers improved semiconductor device processing

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

    capabilities - Energy Innovation Portal Optical Furnace offers improved semiconductor device processing capabilities Award winning solar manufacturing process National Renewable Energy Laboratory Contact NREL About This Technology <p> <em>The highly versatile optical furnace provides semiconductor manufacturers with energy efficient methods to process devices in a high throughput capacity. &nbsp;</em></p> The highly versatile optical furnace provides semiconductor

  13. Optical devices featuring textured semiconductor layers

    DOE Patents [OSTI]

    Moustakas, Theodore D.; Cabalu, Jasper S.

    2011-10-11

    A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

  14. Optical devices featuring textured semiconductor layers

    DOE Patents [OSTI]

    Moustakas, Theodore D.; Cabalu, Jasper S.

    2012-08-07

    A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

  15. Sandia National Laboratories: Power Electronics

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

    Power Electronics Sensors Power electronics is the application of solid-state electronics for routing, control, and conversion of electrical power. Custom Solutions Wide-Bandgap Wide-bandgap semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) have the potential to revolutionize the field of power electronics. Sandia National Laboratories is well-suited to understand both performance and reliability in wide-bandgap power electronics. Understanding Material Properties

  16. Direct-bandgap electroluminescence from a horizontal Ge p-i-n ridge waveguide on Si(001) substrate

    SciTech Connect (OSTI)

    Liu, Zhi; Li, Yaming; He, Chao; Li, Chuanbo; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen Wang, Qiming

    2014-05-12

    Horizontal injection Ge p-i-n ridge waveguide light emitting diodes (LEDs) were fabricated on n{sup ?}-Si(001) substrates by ultrahigh vacuum chemical vapor deposition. The direct-bandgap electroluminescence (EL) of Ge waveguide LEDs under a continuous/pulse electrical pump was studied. The heating effect from a continuous electrical pump was found to significantly enhance the emission of devices. The top surface EL intensity of the Ge waveguide LEDs significantly depended on the position. Most direct-bandgap radiative recombination of Ge p-i-n waveguide LEDs occurred near the N{sup +} region of the junction. This interesting phenomenon could be explained by the carrier distribution in the junction and the pseudo-direct bandgap of Ge.

  17. Solar Semiconductor Pvt Ltd | Open Energy Information

    Open Energy Info (EERE)

    navigation, search Name: Solar Semiconductor Pvt Ltd Place: Hyderabad, Andhra Pradesh, India Zip: 500034 AP Product: Manufacturer of PV modules in Hyderabad, India. Also has an...

  18. Reflection technique for thermal mapping of semiconductors

    DOE Patents [OSTI]

    Walter, Martin J.

    1989-06-20

    Semiconductors may be optically tested for their temperatures by illuminating them with tunable monochromatic electromagnetic radiation and observing the light reflected off of them. A transition point will occur when the wavelength of the light corresponds with the actual band gap energy of the semiconductor. At the transition point, the image of the semiconductor will appreciably darken as the light is transmitted through it, rather than being reflected off of it. The wavelength of the light at the transition point corresponds to the actual band gap energy and the actual temperature of the semiconductor.

  19. Freescale Semiconductor Successfully Implements an Energy Management...

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

    Freescale Semiconductor Successfully Implements an Energy Management System The Superior Energy ... adjusting a fow controller and storage that were not being used to the ...

  20. Gaining creative control over semiconductor nanowires

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

    A Los Alamos research team has transformed the synthesis process of semiconductor nanowires for use in solar cells, batteries, electronics, sensors and photonics using a ...

  1. Earth-abundant semiconductors for photovoltaic applications ...

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

    Earth-abundant semiconductors for photovoltaic applications Thin film photovoltaics (solar cells) has the potential to revolutionize our energy landscape by producing clean,...

  2. Gaining creative control over semiconductor nanowires

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

    Gaining creative control over semiconductor nanowires Using a microfluidic reactor, Los ... Using a microfluidic reactor, Los Alamos researchers transformed the SLS process into a ...

  3. Stangl Semiconductor Equipment AG | Open Energy Information

    Open Energy Info (EERE)

    German manufacturer of wet chemistry systems for processing silicon and thin-film solar cells. References: Stangl Semiconductor Equipment AG1 This article is a stub. You...

  4. Semiconductor nanocrystal probes for biological applications...

    Office of Scientific and Technical Information (OSTI)

    being analyzed, and capable of, in response to exposure to a first energy, providing a second energy. Also described are processes for respectively: making the semiconductor...

  5. Semiconductor Equipment and Materials International SEMI | Open...

    Open Energy Info (EERE)

    search Name: Semiconductor Equipment and Materials International (SEMI) Place: San Jose, California Zip: 95134 2127 Product: Global trade association, publisher and conference...

  6. Electric Drive Semiconductor Manufacturing (EDSM) Center | Department...

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

    and Vehicle Technologies Program Annual Merit Review and Peer Evaluation arravt030apesmith2011p.pdf (331.83 KB) More Documents & Publications Electric Drive Semiconductor ...

  7. Optic probe for semiconductor characterization

    DOE Patents [OSTI]

    Sopori, Bhushan L.; Hambarian, Artak

    2008-09-02

    Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

  8. Processing of insulators and semiconductors

    SciTech Connect (OSTI)

    Quick, Nathaniel R.; Joshi, Pooran C.; Duty, Chad Edward; Jellison, Jr., Gerald Earle; Angelini, Joseph Attilio

    2015-06-16

    A method is disclosed for processing an insulator material or a semiconductor material. The method includes pulsing a plasma lamp onto the material to diffuse a doping substance into the material, to activate the doping substance in the material or to metallize a large area region of the material. The method may further include pulsing a laser onto a selected region of the material to diffuse a doping substance into the material, to activate the doping substance in the material or to metallize a selected region of the material.

  9. the World Wide Web

    Office of Scientific and Technical Information (OSTI)

    technical report has been made electronically available on the World Wide Web through a contribution from Walter L. Warnick In honor of Enrico Fermi Leader of the first nuclear ...

  10. Hybrid anode for semiconductor radiation detectors

    SciTech Connect (OSTI)

    Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

    2013-11-19

    The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).