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Sample records for facility gan m1

  1. ARM - Facility News Article

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

    5, 2011 [Facility News] Team Continues Campaign Planning on Gan Island Bookmark and Share Mike Ritsche, technical operations manager for the AMF2, discusses instrumentation specifics with Gan airport and MMS officials. Mike Ritsche, technical operations manager for the AMF2, discusses instrumentation specifics with Gan airport and MMS officials. For its first international field campaign, the second ARM Mobile Facility (AMF2) is scheduled to operate on Gan Island in the Indian Ocean for the ARM

  2. M 1 Partners | Open Energy Information

    Open Energy Info (EERE)

    Partners Jump to: navigation, search Name: M-1 Partners Place: New York Product: M-1 Partners is a joint venture between Peter Marshall and Robert Ott with the objective of...

  3. ARM MJO Investigation Experiment on Gan Island (AMIE-Gan) Science Plan

    SciTech Connect (OSTI)

    Long, CL; Del Genio, A; Deng, M; Fu, X; Gustafson, W; Houze, R; Jakob, C; Jensen, M; Johnson, R; Liu, X; Luke, E; May, P; McFarlane, S; Minnis, P; Schumacher, C; Vogelmann, A; Wang, Y; Webster, P; Xie, S; Zhang, C

    2011-04-11

    The overarching campaign, which includes the ARM Mobile Facility 2 (AMF2) deployment in conjunction with the Dynamics of the Madden-Julian Oscillation (DYNAMO) and the Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2011) campaigns, is designed to test several current hypotheses regarding the mechanisms responsible for Madden-Julian Oscillation (MJO) initiation and propagation in the Indian Ocean area. The synergy between the proposed AMF2 deployment with DYNAMO/CINDY2011, and the corresponding funded experiment on Manus, combine for an overarching ARM MJO Investigation Experiment (AMIE) with two components: AMF2 on Gan Island in the Indian Ocean (AMIE-Gan), where the MJO initiates and starts its eastward propagation; and the ARM Manus site (AMIE-Manus), which is in the general area where the MJO usually starts to weaken in climate models. AMIE-Gan will provide measurements of particular interest to Atmospheric System Research (ASR) researchers relevant to improving the representation of MJO initiation in climate models. The framework of DYNAMO/CINDY2011 includes two proposed island-based sites and two ship-based locations forming a square pattern with sonde profiles and scanning precipitation and cloud radars at both island and ship sites. These data will be used to produce a Variational Analysis data set coinciding with the one produced for AMIE-Manus. The synergy between AMIE-Manus and AMIE-Gan will allow studies of the initiation, propagation, and evolution of the convective cloud population within the framework of the MJO. As with AMIE-Manus, AMIE-Gan/DYNAMO also includes a significant modeling component geared toward improving the representation of MJO initiation and propagation in climate and forecast models. This campaign involves the deployment of the second, marine-capable, AMF; all of the included measurement systems; and especially the scanning and vertically pointing radars. The campaign will include sonde

  4. Mobile Facility

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

    govSitesMobile Facility AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 MAOS AMF Fact Sheet Images Contacts AMF Deployments McMurdo Station, Antarctica, 2015-2016 Pearl Harbor, Hawaii, to San Francisco, California, 2015 Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010

  5. Facilities

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

    Facilities Facilities LANL's mission is to develop and apply science and technology to ensure the safety, security, and reliability of the U.S. nuclear deterrent; reduce global threats; and solve other emerging national security and energy challenges. Contact Operator Los Alamos National Laboratory (505) 667-5061 Some LANL facilities are available to researchers at other laboratories, universities, and industry. Unique facilities foster experimental science, support the Lab's security mission

  6. Facilities

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

    Secure and Sustainable Energy Future Mission/Facilities Facilities Tara Camacho-Lopez 2016-04-06T18:06:13+00:00 National Solar Thermal Test Facility (NSTTF) facility_nsttf_slide NSTTF's primary goal is to provide experimental engineering data for the design, construction, and operation of unique components and systems in proposed solar thermal electrical plants, which have three generic system architectures: line-focus (trough and continuous linear Fresnel reflector systems), point-focus central

  7. ARM - VAP Product - visstpx08m1rv4minnis

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

    8m1rv4minnis Documentation visst : XDC documentation Data Management Facility Plots (Quick Looks) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send VAP Output : VISSTPX08M1RV4MINNIS VISST-derived pixel-level products from satellite MTSAT, version 4 Active Dates 2008.05.01 - 2008.12.31 Originating VAP Process Minnis Cloud Products Using Visst Algorithm : VISST Measurements The measurements below provided by this

  8. ARM - VAP Product - visstpx04m1rv3minnis

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

    rv3minnis Documentation visst : XDC documentation Data Management Facility Plots (Quick Looks) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send VAP Output : VISSTPX04M1RV3MINNIS VISST-derived pixel-level products from satellite MTSAT, version 3 Active Dates 2007.10.01 - 2007.12.31

  9. ARM - VAP Product - visstpx04m1rv4minnis

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

    rv4minnis Documentation visst : XDC documentation Data Management Facility Plots (Quick Looks) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send VAP Output : VISSTPX04M1RV4MINNIS VISST-derived pixel-level products from satellite MTSAT, version 4 Active Dates 2008.01.01 - 2008.04.30

  10. Facilities

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

    Facilities The the WTGa1 turbine (aka DOE/SNL #1) retuns to power as part of a final series of commissioning tests. Permalink Gallery First Power for SWiFT Turbine Achieved during Recommissioning Facilities, News, Renewable Energy, SWIFT, Wind Energy, Wind News First Power for SWiFT Turbine Achieved during Recommissioning The Department of Energy's Scaled Wind Farm Technology (SWiFT) Facility reached an exciting milestone with the return to power production of the WTGa1 turbine (aka DOE/SNL #1)

  11. ARM - VAP Product - visstpx04m1rv1minnis

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

    rv1minnis Documentation visst : XDC documentation Data Management Facility Plots (Quick Looks) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send VAP Output : VISSTPX04M1RV1MINNIS VISST-derived pixel-level products from satellite MTSAT, version 1 Active Dates 2006.01.01 - 2006.02.28 Originating VAP Process Minnis Cloud Products Using Visst Algorithm : VISST Measurements The measurements below provided by this product

  12. ARM - AMIE Gan Island - Data Plots

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

    Gan Related Links amie.png 34h AMIE Home cindy.png 50h CINDY2011 dynamo.png 34h DYNAMO ARM Data Discovery Browse Data Outreach News & Press Blog Backgrounder (PDF, 1.2MB) Education Flyer (PDF, 2.0MB) Images ARM flickr site Official AMIE Logo AMIE Gear Experiment Planning Steering Committee AMIE-MANUS Proposal Abstract AMIE-GAN Proposal Abstract Meetings Cloud Life Cycle Working Group Deployment Operations Science Plan - TWP Manus Site (PDF, 2.1 MB) Science Plan - Gan Island Site (PDF, 2.0

  13. Facility Floorplan

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

    facility floorplan Facility Floorplan

  14. ARM - Facility News Article

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

    December 21, 2010 [Education, Facility News] NSF Student Travel Fellowship for DYNAMO Field Campaign Bookmark and Share As part of the DYNAMO (Dynamics of the MJO) field campaign, which includes the AMIE-Gan campaign, several student travel fellowships funded by the National Science Foundation are available for advanced graduate students and recently graduated postdoctoral associates, especially those from under-represented groups. DYNAMO is the US contribution to the international field program

  15. ARM - News from the Gan Island Deployment

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

    News from the Gan Island Deployment Related Links amie.png 34h AMIE Home cindy.png 50h CINDY2011 dynamo.png 34h DYNAMO ARM Data Discovery Browse Data Outreach News & Press Blog Backgrounder (PDF, 1.2MB) Education Flyer (PDF, 2.0MB) Images ARM flickr site Official AMIE Logo AMIE Gear Experiment Planning Steering Committee AMIE-MANUS Proposal Abstract AMIE-GAN Proposal Abstract Meetings Cloud Life Cycle Working Group Deployment Operations Science Plan - TWP Manus Site (PDF, 2.1 MB) Science

  16. Observation of 690 MV m^-1 Electron Accelerating Gradient with...

    Office of Scientific and Technical Information (OSTI)

    Observation of 690 MV m-1 Electron Accelerating Gradient with a Laser-Driven Dielectric Microstructure Citation Details In-Document Search Title: Observation of 690 MV m-1...

  17. ARM - Field Campaign - AMIE-Gan Ancillary Disdrometer

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

    govCampaignsAMIE-Gan Ancillary Disdrometer Campaign Links Field Campaign Report ARM Data Discovery Browse Data Related Campaigns ARM MJO Investigation Experiment on Gan Island 2011.10.01, Long, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : AMIE-Gan Ancillary Disdrometer 2012.01.01 - 2012.02.10 Lead Scientist : Mariko Oue For data sets, see below. Abstract As part of the AMIE-Gan campaign, an ancillary disdrometer for comparison

  18. Mission hazard assessment for STARS Mission 1 (M1) in the Marshall Islands area

    SciTech Connect (OSTI)

    Outka, D.E.; LaFarge, R.A.

    1993-07-01

    A mission hazard assessment has been performed for the Strategic Target System Mission 1 (known as STARS M1) for hazards due to potential debris impact in the Marshall Islands area. The work was performed at Sandia National Laboratories as a result of discussion with Kwajalein Missile Range (KMR) safety officers. The STARS M1 rocket will be launched from the Kauai Test Facility (KTF), Hawaii, and deliver two payloads to within the viewing range of sensors located on the Kwajalein Atoll. The purpose of this work has been to estimate upper bounds for expected casualty rates and impact probability or the Marshall Islands areas which adjoin the STARS M1 instantaneous impact point (IIP) trace. This report documents the methodology and results of the analysis.

  19. GaN: Defect and Device Issues

    SciTech Connect (OSTI)

    Pearton, S.J.; Ren, F.; Shul, R.J.; Zolper, J.C.

    1998-11-09

    The role of extended and point defects, and key impurities such as C, O and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

  20. Ge doped GaN with controllable high carrier concentration for...

    Office of Scientific and Technical Information (OSTI)

    Ge doped GaN with controllable high carrier concentration for plasmonic applications Citation Details In-Document Search Title: Ge doped GaN with controllable high carrier...

  1. High Voltage GaN Schottky Rectifiers

    SciTech Connect (OSTI)

    CAO,X.A.; CHO,H.; CHU,S.N.G.; CHUO,C.-C.; CHYI,J.-I.; DANG,G.T.; HAN,JUNG; LEE,C.-M.; PEARTON,S.J.; REN,F.; WILSON,R.G.; ZHANG,A.P.

    1999-10-25

    Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.

  2. Conductivity based on selective etch for GaN devices and applications thereof

    DOE Patents [OSTI]

    Zhang, Yu; Sun, Qian; Han, Jung

    2015-12-08

    This invention relates to methods of generating NP gallium nitride (GaN) across large areas (>1 cm.sup.2) with controlled pore diameters, pore density, and porosity. Also disclosed are methods of generating novel optoelectronic devices based on porous GaN. Additionally a layer transfer scheme to separate and create free-standing crystalline GaN thin layers is disclosed that enables a new device manufacturing paradigm involving substrate recycling. Other disclosed embodiments of this invention relate to fabrication of GaN based nanocrystals and the use of NP GaN electrodes for electrolysis, water splitting, or photosynthetic process applications.

  3. Highly transparent ammonothermal bulk GaN substrates

    SciTech Connect (OSTI)

    Jiang, WK; Ehrentraut, D; Downey, BC; Kamber, DS; Pakalapati, RT; Do Yoo, H; D'Evelyn, MP

    2014-10-01

    A novel apparatus has been employed to grow ammonothermal (0001) gallium nitride (GaN) with diameters up to 2 in The crystals have been characterized by x-ray diffraction rocking-curve (XRC) analysis, optical and scanning electron microscopy (SEM), cathodoluminescence (CL), and optical spectroscopy. High crystallinity GaN with FWHM values about 20-50 arcsec and dislocation densities below 1 x 10(5) cm(-2) have been obtained. High optical transmission was achieved with an optical absorption coefficient below 1 cm(-1) at a wavelength of 450 nm. (C) 2014 Elsevier B.V. All rights reserved.

  4. Ferromagnetism in undoped One-dimensional GaN Nanowires

    SciTech Connect (OSTI)

    Jeganathan, K. E-mail: jagan@physics.bdu.ac.in; Purushothaman, V.; Debnath, R.; Arumugam, S.

    2014-05-15

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

  5. Properties of H, O and C in GaN

    SciTech Connect (OSTI)

    Pearton, S.J.; Abernathy, C.R.; Lee, J.W.

    1996-04-01

    The electrical properties of the light ion impurities H, O and C in GaN have been examined in both as-grown and implanted material. H is found to efficiently passivate acceptors such as Mg, Ca and C. Reactivation occurs at {ge} 450 C and is enhanced by minority carrier injection. The hydrogen does not leave the GaN crystal until > 800 C, and its diffusivity is relatively high ({approximately} 10{sup {minus}11} cm{sup 2}/s) even at low temperatures (< 200 C) during injection by wet etching, boiling in water or plasma exposure. Oxygen shows a low donor activation efficiency when implanted into GaN, with an ionization level of 30--40 meV. It is essentially immobile up to 1,100 C. Carbon can produce low p-type levels (3 {times} 10{sup 17} cm{sup {minus}3}) in GaN during MOMBE, although there is some evidence it may also create n-type conduction in other nitrides.

  6. Refractive index of erbium doped GaN thin films

    SciTech Connect (OSTI)

    Alajlouni, S.; Sun, Z. Y.; Li, J.; Lin, J. Y.; Jiang, H. X.; Zavada, J. M.

    2014-08-25

    GaN is an excellent host for erbium (Er) to provide optical emission in the technologically important as well as eye-safe 1540 nm wavelength window. Er doped GaN (GaN:Er) epilayers were synthesized on c-plane sapphire substrates using metal organic chemical vapor deposition. By employing a pulsed growth scheme, the crystalline quality of GaN:Er epilayers was significantly improved over those obtained by conventional growth method of continuous flow of reaction precursors. X-ray diffraction rocking curve linewidths of less than 300 arc sec were achieved for the GaN (0002) diffraction peak, which is comparable to the typical results of undoped high quality GaN epilayers and represents a major improvement over previously reported results for GaN:Er. Spectroscopic ellipsometry was used to determine the refractive index of the GaN:Er epilayers in the 1540 nm wavelength window and a linear dependence on Er concentration was found. The observed refractive index increase with Er incorporation and the improved crystalline quality of the GaN:Er epilayers indicate that low loss GaN:Er optical waveguiding structures are feasible.

  7. AMIE Gan Island Ancillary Disdrometer Field Campaign...

    Office of Scientific and Technical Information (OSTI)

    Ancillary Disdrometer Field Campaign Report M Oue April 2016 CLIMATE RESEARCH FACILITY DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. ...

  8. Structural defects in GaN revealed by Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Liliental-Weber, Zuzanna

    2014-04-18

    This paper reviews the various types of structural defects observed by Transmission Electron Microscopy in GaN heteroepitaxial layers grown on foreign substrates and homoepitaxial layers grown on bulk GaN substrates. The structural perfection of these layers is compared to the platelet self-standing crystals grown by High Nitrogen Pressure Solution. Defects in undoped and Mg doped GaN are discussed. Some models explaining the formation of inversion domains in heavily Mg doped layers that are possible defects responsible for the difficulties of p-doping in GaN are also reviewed.

  9. Structural defects in GaN revealed by Transmission Electron Microscopy

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

    Liliental-Weber, Zuzanna

    2014-09-08

    This paper reviews the various types of structural defects observed by Transmission Electron Microscopy in GaN heteroepitaxial layers grown on foreign substrates and homoepitaxial layers grown on bulk GaN substrates. The structural perfection of these layers is compared to the platelet self-standing crystals grown by High Nitrogen Pressure Solution. Defects in undoped and Mg doped GaN are discussed. Lastly, some models explaining the formation of inversion domains in heavily Mg doped layers that are possible defects responsible for the difficulties of p-doping in GaN are also reviewed.

  10. Nuclear Facilities Production Facilities

    National Nuclear Security Administration (NNSA)

    Facilities Production Facilities Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Sand 2011-4582P. ENERGY U.S. DEPARTMENT OF Gamma Irradiation Facility (GIF) The GIF provides test cells for the irradiation of experiments with high-intensity gamma ray sources. The main features

  11. ARM - SGP Extended Facility

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

    Extended Facility SGP Related Links Virtual Tour Facilities and Instruments Central Facility Boundary Facility Extended Facility Intermediate Facility Radiometric Calibration...

  12. ARM - SGP Intermediate Facility

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

    Intermediate Facility SGP Related Links Virtual Tour Facilities and Instruments Central Facility Boundary Facility Extended Facility Intermediate Facility Radiometric Calibration...

  13. ARM - SGP Central Facility

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

    Central Facility SGP Related Links Virtual Tour Facilities and Instruments Central Facility Boundary Facility Extended Facility Intermediate Facility Radiometric Calibration...

  14. This invention relates to methods of generating NP gallium nitride (GaN) across large areas (>1 cm.sup.2) with controlled pore diameters, pore density, and porosity. Also disclosed are methods of generating novel optoelectronic devices based on porous GaN. Additionally a layer transfer scheme to separate and create free-standing crystalline GaN thin layers is disclosed that enables a new device manufacturing paradigm involving substrate recycling. Other disclosed embodiments of this invention relate to fabrication of GaN based nanocrystals and the use of NP GaN electrodes for electrolysis, water splitting, or photosynthetic process applications.

    DOE Patents [OSTI]

    Zhang, Yu; Sun, Qian; Han, Jung

    2015-12-08

    This invention relates to methods of generating NP gallium nitride (GaN) across large areas (>1 cm.sup.2) with controlled pore diameters, pore density, and porosity. Also disclosed are methods of generating novel optoelectronic devices based on porous GaN. Additionally a layer transfer scheme to separate and create free-standing crystalline GaN thin layers is disclosed that enables a new device manufacturing paradigm involving substrate recycling. Other disclosed embodiments of this invention relate to fabrication of GaN based nanocrystals and the use of NP GaN electrodes for electrolysis, water splitting, or photosynthetic process applications.

  15. Huntington Resource Recovery Facility Biomass Facility | Open...

    Open Energy Info (EERE)

    Resource Recovery Facility Biomass Facility Jump to: navigation, search Name Huntington Resource Recovery Facility Biomass Facility Facility Huntington Resource Recovery Facility...

  16. Wheelabrator Sherman Energy Facility Biomass Facility | Open...

    Open Energy Info (EERE)

    Sherman Energy Facility Biomass Facility Jump to: navigation, search Name Wheelabrator Sherman Energy Facility Biomass Facility Facility Wheelabrator Sherman Energy Facility Sector...

  17. Growth and Band Offsets of Epitaxial Lanthanide Oxides on GaN...

    Office of Scientific and Technical Information (OSTI)

    M.T.T., 60 (6) (2012) 3 Jon Ihlefeld, Sandia National Laboratories Electronic Materials ... Undoped GaN Undoped AlGaN Doped AlGaN 2D Electron Gas Enhancement Mode (nominally ...

  18. Dislocation confinement in the growth of Na flux GaN on metalorganic...

    Office of Scientific and Technical Information (OSTI)

    Dislocation confinement in the growth of Na flux GaN on metalorganic chemical vapor deposition-GaN Citation Details In-Document Search Title: Dislocation confinement in the growth ...

  19. Low temperature thin film transistors with hollow cathode plasma-assisted atomic layer deposition based GaN channels

    SciTech Connect (OSTI)

    Bolat, S. E-mail: aokyay@ee.bilkent.edu.tr; Tekcan, B.; Ozgit-Akgun, C.; Biyikli, N.; Okyay, A. K. E-mail: aokyay@ee.bilkent.edu.tr

    2014-06-16

    We report GaN thin film transistors (TFT) with a thermal budget below 250?C. GaN thin films are grown at 200?C by hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD). HCPA-ALD-based GaN thin films are found to have a polycrystalline wurtzite structure with an average crystallite size of 9.3?nm. TFTs with bottom gate configuration are fabricated with HCPA-ALD grown GaN channel layers. Fabricated TFTs exhibit n-type field effect characteristics. N-channel GaN TFTs demonstrated on-to-off ratios (I{sub ON}/I{sub OFF}) of 10{sup 3} and sub-threshold swing of 3.3?V/decade. The entire TFT device fabrication process temperature is below 250?C, which is the lowest process temperature reported for GaN based transistors, so far.

  20. Hybrid device based on GaN nanoneedles and MEH-PPV/PEDOT:PSS polymer

    SciTech Connect (OSTI)

    Shin, Min Jeong; Gwon, Dong-Oh; Lee, Chan-Mi; Lee, Gang Seok; Jeon, In-Jun; Ahn, Hyung Soo; Yi, Sam Nyung; Ha, Dong Han

    2015-08-15

    Highlights: • A hybrid device was demonstrated by using MEH-PPV, PEDOT:PSS, and GaN nanoneedles. • I–V curve of the hybrid device showed its rectification behaviour, similar to a diode. • EL peak originated by the different potential barriers at MEH-PPV and GaN interface. - Abstract: A hybrid device that combines the properties of organic and inorganic semiconductors was fabricated and studied. It incorporated poly[2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as organic polymers and GaN nanoneedles as an inorganic semiconductor. Layers of the two polymers were spin coated on to the GaN nanoneedles. The one peak in the electroluminescence spectrum originated from the MEH-PPV layer owing to the different potential barriers of electrons and holes at its interface with the GaN nanoneedles. However, the photoluminescence spectrum showed peaks due to both GaN nanoneedles and MEH-PPV. Such hybrid structures, suitably developed, might be able to improve the efficiency of optoelectronic devices.

  1. Ashton Extended Facility

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

    Ashton Extended Facility Map

  2. Byron Extended Facility

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

    Byron Extended Facility Map

  3. Intrinsic polarization control in rectangular GaN nanowire lasers

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

    Li, Changyi; Liu, Sheng; Luk, Ting S.; Figiel, Jeffrey J.; Brener, Igal; Brueck, S. R. J.; Wang, George T.

    2016-02-01

    In this study, we demonstrate intrinsic, linearly polarized lasing from single GaN nanowires using cross-sectional shape control. A two-step top-down fabrication approach was employed to create straight nanowires with controllable rectangular cross-sections. A clear lasing threshold of 444kW/cm2 and a narrow spectral line width of 0.16 nm were observed under optical pumping at room temperature, indicating the onset of lasing. The polarization was along the short dimension (y-direction) of the nanowire due to the higher transverse confinement factors for y-polarized transverse modes resulting from the rectangular nanowire cross-section. The results show that cross-sectioned shape control can enable inherent control overmore » the polarization of nanowire lasers without additional environment requirements, such as placement onto lossy substrates.« less

  4. User Facilities

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

    User Facilities User Facilities User facility agreements allow Los Alamos partners and other entities to conduct research at our unique facilities. In 2011, LANL hosted more than 1,200 users at CINT, LANSCE, and NHMFL. Users came from across the DOE complex, from international academia, and from industrial companies from 45 states across the U.S. Unique world-class user facilities foster rich research opportunities Through its technology transfer efforts, LANL can implement user facility

  5. SECTION M EVALUATION FACTORS FOR AWARD TABLE OF CONTENTS M-1 EVALUATION OF PROPOSALS .....................................................................................2

    National Nuclear Security Administration (NNSA)

    M EVALUATION FACTORS FOR AWARD TABLE OF CONTENTS M-1 EVALUATION OF PROPOSALS .....................................................................................2 M-2 BASIS FOR CONTRACT AWARD ...................................................................................3 M-3 TECHNICAL AND MANAGEMENT CRITERIA ..........................................................3 M-4 COST CRITERION

  6. SECTION M EVALUATION FACTORS FOR AWARD TABLE OF CONTENTS M-1 EVALUATION OF PROPOSALS .....................................................................................2

    National Nuclear Security Administration (NNSA)

    TABLE OF CONTENTS M-1 EVALUATION OF PROPOSALS .....................................................................................2 M-2 BASIS FOR CONTRACT AWARD ...................................................................................3 M-3 TECHNICAL AND MANAGEMENT CRITERIA ..........................................................3 M-4 COST EVALUATION CRITERION .................................................................................5 Section M, Evaluation Factors Request for

  7. High active nitrogen flux growth of GaN by plasma assisted molecular beam epitaxy

    SciTech Connect (OSTI)

    McSkimming, Brian M. Speck, James S.; Chaix, Catherine

    2015-09-15

    In the present study, the authors report on a modified Riber radio frequency (RF) nitrogen plasma source that provides active nitrogen fluxes more than 30 times higher than those commonly used for plasma assisted molecular beam epitaxy (PAMBE) growth of gallium nitride (GaN) and thus a significantly higher growth rate than has been previously reported. GaN films were grown using N{sub 2} gas flow rates between 5 and 25 sccm while varying the plasma source's RF forward power from 200 to 600 W. The highest growth rate, and therefore the highest active nitrogen flux, achieved was ∼7.6 μm/h. For optimized growth conditions, the surfaces displayed a clear step-terrace structure with an average RMS roughness (3 × 3 μm) on the order of 1 nm. Secondary ion mass spectroscopy impurity analysis demonstrates oxygen and hydrogen incorporation of 1 × 10{sup 16} and ∼5 × 10{sup 17}, respectively. In addition, the authors have achieved PAMBE growth of GaN at a substrate temperature more than 150 °C greater than our standard Ga rich GaN growth regime and ∼100 °C greater than any previously reported PAMBE growth of GaN. This growth temperature corresponds to GaN decomposition in vacuum of more than 20 nm/min; a regime previously unattainable with conventional nitrogen plasma sources. Arrhenius analysis of the decomposition rate shows that samples with a flux ratio below stoichiometry have an activation energy greater than decomposition of GaN in vacuum while samples grown at or above stoichiometry have decreased activation energy. The activation energy of decomposition for GaN in vacuum was previously determined to be ∼3.1 eV. For a Ga/N flux ratio of ∼1.5, this activation energy was found to be ∼2.8 eV, while for a Ga/N flux ratio of ∼0.5, it was found to be ∼7.9 eV.

  8. Facility Representatives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-03-01

    This standard, DOE-STD-1063, Facility Representatives, defines the duties, responsibilities and qualifications for Department of Energy (DOE) Facility Representatives, based on facility hazard classification; risks to workers, the public, and the environment; and the operational activity level. This standard provides the guidance necessary to ensure that DOE’s hazardous nuclear and non-nuclear facilities have sufficient staffing of technically qualified facility representatives (FRs) to provide day-to-day oversight of contractor operations.

  9. User Facilities

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

    User Facilities User Facilities A new research frontier awaits! Our door is open, and we thrive on mutually beneficial partnerships and collaborations that drive innovations and new technologies. Unique world-class user facilities foster rich research opportunities Through its technology transfer efforts, Los Alamos National Laboratory can implement user facility agreements that allow its partners and other entities to conduct research at many of its unique facilities. While our largest user

  10. GaN Initiative for Grid Applications (GIGA)

    SciTech Connect (OSTI)

    Turner, George

    2015-07-03

    For nearly 4 ½ years, MIT Lincoln Laboratory (MIT/LL) led a very successful, DoE-funded team effort to develop GaN-on-Si materials and devices, targeting high-voltage (>1 kV), high-power, cost-effective electronics for grid applications. This effort, called the GaN Initiative for Grid Applications (GIGA) program, was initially made up of MIT/LL, the MIT campus group of Prof. Tomas Palacios (MIT), and the industrial partner M/A Com Technology Solutions (MTS). Later in the program a 4th team member was added (IQE MA) to provide commercial-scale GaN-on-Si epitaxial materials. A basic premise of the GIGA program was that power electronics, for ubiquitous utilization -even for grid applications - should be closer in cost structure to more conventional Si-based power electronics. For a number of reasons, more established GaN-on-SiC or even SiC-based power electronics are not likely to reach theses cost structures, even in higher manufacturing volumes. An additional premise of the GIGA program was that the technical focus would be on materials and devices suitable for operating at voltages > 1 kV, even though there is also significant commercial interest in developing lower voltage (< 1 kV), cost effective GaN-on-Si devices for higher volume applications, like consumer products. Remarkable technical progress was made during the course of this program. Advances in materials included the growth of high-quality, crack-free epitaxial GaN layers on large-diameter Si substrates with thicknesses up to ~5 μm, overcoming significant challenges in lattice mismatch and thermal expansion differences between Si and GaN in the actual epitaxial growth process. Such thick epilayers are crucial for high voltage operation of lateral geometry devices such as Schottky barrier (SB) diodes and high electron mobility transistors (HEMTs). New “Normally-Off” device architectures were demonstrated – for safe operation of power electronics circuits. The trade-offs between lateral and

  11. Nanostructural engineering of nitride nucleation layers for GaN substrate dislocation reduction.

    SciTech Connect (OSTI)

    Koleske, Daniel David; Lee, Stephen Roger; Lemp, Thomas Kerr; Coltrin, Michael Elliott; Cross, Karen Charlene; Thaler, Gerald

    2009-07-01

    With no lattice matched substrate available, sapphire continues as the substrate of choice for GaN growth, because of its reasonable cost and the extensive prior experience using it as a substrate for GaN. Surprisingly, the high dislocation density does not appear to limit UV and blue LED light intensity. However, dislocations may limit green LED light intensity and LED lifetime, especially as LEDs are pushed to higher current density for high end solid state lighting sources. To improve the performance for these higher current density LEDs, simple growth-enabled reductions in dislocation density would be highly prized. GaN nucleation layers (NLs) are not commonly thought of as an application of nano-structural engineering; yet, these layers evolve during the growth process to produce self-assembled, nanometer-scale structures. Continued growth on these nuclei ultimately leads to a fully coalesced film, and we show in this research program that their initial density is correlated to the GaN dislocation density. In this 18 month program, we developed MOCVD growth methods to reduce GaN dislocation densities on sapphire from 5 x 10{sup 8} cm{sup -2} using our standard delay recovery growth technique to 1 x 10{sup 8} cm{sup -2} using an ultra-low nucleation density technique. For this research, we firmly established a correlation between the GaN nucleation thickness, the resulting nucleation density after annealing, and dislocation density of full GaN films grown on these nucleation layers. We developed methods to reduce the nuclei density while still maintaining the ability to fully coalesce the GaN films. Ways were sought to improve the GaN nuclei orientation by improving the sapphire surface smoothness by annealing prior to the NL growth. Methods to eliminate the formation of additional nuclei once the majority of GaN nuclei were developed using a silicon nitride treatment prior to the deposition of the nucleation layer. Nucleation layer thickness was determined

  12. E1 and M1 γ-strength functions in 144Nd

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

    Voinov, A. V.; Grimes, S. M.

    2015-12-14

    Both E1 and M1 γ-strength functions below the neutron separation energy were analyzed based on experimental data from 143Nd(n,γ)144Nd and 143Nd(n,γα)140Ce reactions. It is confirmed that the commonly adopted E1 model based on the temperature dependence of the width of the giant dipole resonance works well. The popular M1 strength function due to the spin-flip magnetic resonance located near the neutron binding energy is not capable of reproducing experimental data. As a result, the low-energy enhancement of the M1 strength or the energy-independent model of Weisskopf, both leading to the low-energy strength sizable to E1 one, fit experimental data best.

  13. ORISE: Facilities

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

    ORISE Facilities Unique laboratories and training centers among the assets managed on behalf of the U.S. Department of Energy The Oak Ridge Institute for Science and Education (ORISE) is home to a number of on- and off-site facilities that support the U.S. Department of Energy's (DOE) science education and research mission. From on-site medical laboratories to radiation emergency medicine training facilities, ORISE facilities are helping to address national needs in the following areas:

  14. Science Facilities

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

    Facilities Science Facilities The focal point for basic and applied R&D programs with a primary focus on energy but also encompassing medical, biotechnology, high-energy physics, and advanced scientific computing programs. Center for Integrated Nanotechnologies» Dual Axis Radiographic Hydrodynamic Test Facility (DARHT)» Electron Microscopy Lab» Ion Beam Materials Lab» Isotope Production Facility» Los Alamos Neutron Science Center» Lujan Center» Matter-Radiation Interactions in

  15. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-10-24

    Establishes facility safety requirements related to: nuclear safety design, criticality safety, fire protection and natural phenomena hazards mitigation.

  16. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-11-16

    Establishes facility safety requirements related to: nuclear safety design, criticality safety, fire protection and natural phenomena hazards mitigation.

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

    SciTech Connect (OSTI)

    Kuppulingam, B. Singh, Shubra Baskar, K.

    2014-04-24

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

  18. Wheelabrator Millbury Facility Biomass Facility | Open Energy...

    Open Energy Info (EERE)

    Facility Facility Wheelabrator Millbury Facility Sector Biomass Facility Type Municipal Solid Waste Location Worcester County, Massachusetts Coordinates 42.4096528, -71.8571331...

  19. Electrical and optical properties of carbon-doped GaN grown by MBE on MOCVD GaN templates using a CCl4 dopant source

    SciTech Connect (OSTI)

    Armitage, Rob; Yang, Qing; Feick, Henning; Park, Yeonjoon; Weber, Eicke R.

    2002-04-15

    Carbon-doped GaN was grown by plasma-assisted molecular-beam epitaxy using carbon tetrachloride vapor as the dopant source. For moderate doping mainly acceptors were formed, yielding semi-insulating GaN. However at higher concentrations p-type conductivity was not observed, and heavily doped films (>5 x 10{sup 20} cm{sup -3}) were actually n-type rather than semi-insulating. Photoluminescence measurements showed two broad luminescence bands centered at 2.2 and 2.9 eV. The intensity of both bands increased with carbon content, but the 2.2 eV band dominated in n-type samples. Intense, narrow ({approx}6 meV) donor-bound exciton peaks were observed in the semi-insulating samples.

  20. New probe of M1 and E1 strengths in GDR regions

    SciTech Connect (OSTI)

    Hayakawa, T. [Japan Atomic Energy Agency and National Astronomical Observatory in Japan (Japan); Ogata, K. [RCNP, Osaka University (Japan); Miyamoto, S.; Mochizuki, T.; Horikawa, K.; Amano, S. [University of Hyogo (Japan); Imazaki, K.; Li, D.; Izawa, Y. [Institute for Laser Technology (Japan); Chiba, S. [Tokyo Institute of Technology (Japan)

    2014-05-02

    The M1 strengths (or level density of 1{sup +} states) are of importance for estimation of interaction strengths between neutrinos and nuclei for the study of the supernova neutrino-process. In 1957, Agodi predicted theoretically angular distribution of neutrons emitted from states excited via dipole transitions with linearly polarized gamma-ray beam at the polar angle of ?=90 should be followed by a simple function, a + b cos(2?), where ?, is azimuthal angel. However, this theoretical prediction has not been verified over the wide mass region except for light nuclei as deuteron. We have measured neutron angular distributions with (polarized gamma, n) reactions on Au, Nal, and Cu. We have verified the Agodi's prediction for the first time over the wide mass region. This suggests that (polarized gamma, n) reactions may be useful tools to study M1 strengths in giant resonance regions.

  1. Surface Termination of M1 Phase and Rational Design of Propane Ammoxidation Catalysts

    SciTech Connect (OSTI)

    Guliants, Vadim

    2015-02-16

    This final report describes major accomplishments in this research project which has demonstrated that the M1 phase is the only crystalline phase required for propane ammoxidation to acrylonitrile and that a surface monolayer terminating the ab planes of the M1 phase is responsible for their activity and selectivity in this reaction. Fundamental studies of the topmost surface chemistry and mechanism of propane ammoxidation over the Mo-V-(Te,Sb)-(Nb,Ta)-O M1 and M2 phases resulted in the development of quantitative understanding of the surface molecular structure – reactivity relationships for this unique catalytic system. These oxides possess unique catalytic properties among mixed metal oxides, because they selectively catalyze three alkane transformation reactions, namely propane ammoxidation to acrylonitrile, propane oxidation to acrylic acid and ethane oxidative dehydrogenation, all of considerable economic significance. Therefore, the larger goal of this research was to expand this catalysis to other alkanes of commercial interest, and more broadly, demonstrate successful approaches to rational design of improved catalysts that can be applied to other selective (amm)oxidation processes.

  2. Beamlines & Facilities

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

    Imaging Group: Beamlines The X-ray Micrscopy and Imaging Group operates several beamlines and facilities. The bending magnet beamline (2-BM) entertaines 2 general user programs in...

  3. Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep

    2013-01-28

    We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can mitigate losses incurred in hot-carrier injection in light emitting heterostructures. To achieve tunnel injection, relatively low composition AlGaN is used for n- and p-type layers to simultaneously take advantage of effective band alignment and efficient doping. The small height of the quantum dots results in short-wavelength emission and are simultaneously an effective tool to fight the reduction of oscillator strength from quantum-confined Stark effect due to polarization fields. The strong quantum confinement results in room-temperature electroluminescence peaks at 261 and 340 nm, well above the 365 nm bandgap of bulk GaN. The demonstration opens the doorway to exploit many varied features of quantum dot physics to realize high-efficiency short-wavelength light sources.

  4. Ultra High p-doping Material Research for GaN Based Light Emitters

    SciTech Connect (OSTI)

    Vladimir Dmitriev

    2007-06-30

    The main goal of the Project is to investigate doping mechanisms in p-type GaN and AlGaN and controllably fabricate ultra high doped p-GaN materials and epitaxial structures. Highly doped p-type GaN-based materials with low electrical resistivity and abrupt doping profiles are of great importance for efficient light emitters for solid state lighting (SSL) applications. Cost-effective hydride vapor phase epitaxial (HVPE) technology was proposed to investigate and develop p-GaN materials for SSL. High p-type doping is required to improve (i) carrier injection efficiency in light emitting p-n junctions that will result in increasing of light emitting efficiency, (ii) current spreading in light emitting structures that will improve external quantum efficiency, and (iii) parameters of Ohmic contacts to reduce operating voltage and tolerate higher forward currents needed for the high output power operation of light emitters. Highly doped p-type GaN layers and AlGaN/GaN heterostructures with low electrical resistivity will lead to novel device and contact metallization designs for high-power high efficiency GaN-based light emitters. Overall, highly doped p-GaN is a key element to develop light emitting devices for the DOE SSL program. The project was focused on material research for highly doped p-type GaN materials and device structures for applications in high performance light emitters for general illumination P-GaN and p-AlGaN layers and multi-layer structures were grown by HVPE and investigated in terms of surface morphology and structure, doping concentrations and profiles, optical, electrical, and structural properties. Tasks of the project were successfully accomplished. Highly doped GaN materials with p-type conductivity were fabricated. As-grown GaN layers had concentration N{sub a}-N{sub d} as high as 3 x 10{sup 19} cm{sup -3}. Mechanisms of doping were investigated and results of material studies were reported at several International conferences providing

  5. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-12-22

    This Order establishes facility and programmatic safety requirements for Department of Energy facilities, which includes nuclear and explosives safety design criteria, fire protection, criticality safety, natural phenomena hazards mitigation, and the System Engineer Program. Cancels DOE O 420.1A. DOE O 420.1B Chg 1 issued 4-19-10.

  6. Facility Representatives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-04-06

    REPLACED BY DOE-STD-1063 | SUPERSEDING DOE-STD-1063-2000 (MARCH 2000) The purpose of the DOE Facility Representative Program is to ensure that competent DOE staff personnel are assigned to oversee the day-to-day contractor operations at DOE’s hazardous nuclear and non-nuclear facilities.

  7. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2012-12-04

    The Order establishes facility and programmatic safety requirements for DOE and NNSA for nuclear safety design criteria, fire protection, criticality safety, natural phenomena hazards (NPH) mitigation, and System Engineer Program. This Page Change is limited in scope to changes necessary to invoke DOE-STD-1104, Review and Approval of Nuclear Facility Safety Basis and Safety Design Basis Document, and revised DOE-STD-3009-2014, Preparation of Nonreactor Nuclear Facility Documented Safety Analysis as required methods. DOE O 420.1C Chg 1, dated 2-27-15, supersedes DOE O 420.1C.

  8. Influence of growth temperature and temperature ramps on deep level defect incorporation in m-plane GaN

    SciTech Connect (OSTI)

    Armstrong, A. M.; Kelchner, K.; Nakamura, S.; DenBaars, S. P.; Materials Department, University of California, Santa Barbara, California 93106 ; Speck, J. S.

    2013-12-02

    The dependence of deep level defect incorporation in m-plane GaN films grown by metal-organic chemical vapor deposition on bulk m-plane GaN substrates as a function of growth temperature (T{sub g}) and T{sub g} ramping method was investigated using deep level optical spectroscopy. Understanding the influence of T{sub g} on GaN deep level incorporation is important for InGaN/GaN multi-quantum well (MQW) light emitting diodes (LEDs) and laser diodes (LDs) because GaN quantum barrier (QB) layers are grown much colder than thin film GaN to accommodate InGaN QW growth. Deep level spectra of low T{sub g} (800?C) GaN films grown under QB conditions were compared to deep level spectra of high T{sub g} (1150?C) GaN. Reducing T{sub g}, increased the defect density significantly (>50) through introduction of emergent deep level defects at 2.09?eV and 2.9?eV below the conduction band minimum. However, optimizing growth conditions during the temperature ramp when transitioning from high to low T{sub g} substantially reduced the density of these emergent deep levels by approximately 40%. The results suggest that it is important to consider the potential for non-radiative recombination in QBs of LED or LD active regions, and tailoring the transition from high T{sub g} GaN growth to active layer growth can mitigate such non-radiative channels.

  9. Total Energy Facilities Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    Energy Facilities Biomass Facility Jump to: navigation, search Name Total Energy Facilities Biomass Facility Facility Total Energy Facilities Sector Biomass Facility Type...

  10. Gas Utilization Facility Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    Gas Utilization Facility Biomass Facility Jump to: navigation, search Name Gas Utilization Facility Biomass Facility Facility Gas Utilization Facility Sector Biomass Facility Type...

  11. Localized tip enhanced Raman spectroscopic study of impurity incorporated single GaN nanowire in the sub-diffraction limit

    SciTech Connect (OSTI)

    Patsha, Avinash E-mail: dhara@igcar.gov.in; Dhara, Sandip; Tyagi, A. K.

    2015-09-21

    The localized effect of impurities in single GaN nanowires in the sub-diffraction limit is reported using the study of lattice vibrational modes in the evanescent field of Au nanoparticle assisted tip enhanced Raman spectroscopy (TERS). GaN nanowires with the O impurity and the Mg dopants were grown by the chemical vapor deposition technique in the catalyst assisted vapor-liquid-solid process. Symmetry allowed Raman modes of wurtzite GaN are observed for undoped and doped nanowires. Unusually very strong intensity of the non-zone center zone boundary mode is observed for the TERS studies of both the undoped and the Mg doped GaN single nanowires. Surface optical mode of A{sub 1} symmetry is also observed for both the undoped and the Mg doped GaN samples. A strong coupling of longitudinal optical (LO) phonons with free electrons, however, is reported only in the O rich single nanowires with the asymmetric A{sub 1}(LO) mode. Study of the local vibration mode shows the presence of Mg as dopant in the single GaN nanowires.

  12. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2002-05-20

    To establish facility safety requirements for the Department of Energy, including National Nuclear Security Administration. Cancels DOE O 420.1. Canceled by DOE O 420.1B.

  13. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-12-22

    The order establishes facility and programmatic safety requirements for nuclear and explosives safety design criteria, fire protection, criticality safety, natural phenomena hazards (NPH) mitigation, and the System Engineer Program.Chg 1 incorporates the use of DOE-STD-1189-2008, Integration of Safety into the Design Process, mandatory for Hazard Category 1, 2 and 3 nuclear facilities. Cancels DOE O 420.1A.

  14. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2013-06-21

    DOE-STD-1104 contains the Department's method and criteria for reviewing and approving nuclear facility's documented safety analysis (DSA). This review and approval formally document the basis for DOE, concluding that a facility can be operated safely in a manner that adequately protects workers, the public, and the environment. Therefore, it is appropriate to formally require implementation of the review methodology and criteria contained in DOE-STD-1104.

  15. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2000-11-20

    The objective of this Order is to establish facility safety requirements related to: nuclear safety design, criticality safety, fire protection and natural phenomena hazards mitigation. The Order has Change 1 dated 11-16-95, Change 2 dated 10-24-96, and the latest Change 3 dated 11-22-00 incorporated. The latest change satisfies a commitment made to the Defense Nuclear Facilities Safety Board (DNFSB) in response to DNFSB recommendation 97-2, Criticality Safety.

  16. Working with SRNL - Our Facilities - Glovebox Facilities

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

    SRNL Our Facilities - Glovebox Facilities Govebox Facilities are sealed, protectively-lined compartments with attached gloves, allowing workers to safely handle dangerous materials...

  17. SLAC Accelerator Test Facilities

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

    FACET & TF Careers & Education Archived FACET User Facility Quick Launch About FACET & Test Facilities Expand About FACET & Test Facilities FACET & Test Facilities User Portal...

  18. Search for 14.4 keV solar axions from M1 transition of Fe-57...

    Office of Scientific and Technical Information (OSTI)

    Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals Citation Details In-Document Search Title: Search for 14.4 keV solar axions from M1 transition of...

  19. Performance and breakdown characteristics of irradiated vertical power GaN P-i-N diodes

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

    King, M. P.; Armstrong, A. M.; Dickerson, J. R.; Vizkelethy, G.; Fleming, R. M.; Campbell, J.; Wampler, W. R.; Kizilyalli, I. C.; Bour, D. P.; Aktas, O.; et al

    2015-10-29

    Electrical performance and defect characterization of vertical GaN P-i-N diodes before and after irradiation with 2.5 MeV protons and neutrons is investigated. Devices exhibit increase in specific on-resistance following irradiation with protons and neutrons, indicating displacement damage introduces defects into the p-GaN and n- drift regions of the device that impact on-state device performance. The breakdown voltage of these devices, initially above 1700 V, is observed to decrease only slightly for particle fluence <; 1013 cm-2. Furthermore, the unipolar figure of merit for power devices indicates that while the on-resistance and breakdown voltage degrade with irradiation, vertical GaN P-i-Ns remainmore » superior to the performance of the best available, unirradiated silicon devices and on-par with unirradiated modern SiC-based power devices.« less

  20. Surfactant assisted growth of MgO films on GaN

    SciTech Connect (OSTI)

    Paisley, E. A.; Shelton, T. C.; Collazo, R.; Sitar, Z.; Maria, J.-P.; Christen, H. M.; Biegalski, M. D.; Mita, S.

    2012-08-27

    Thin epitaxial films of <111> oriented MgO on [0001]-oriented GaN were grown by molecular beam epitaxy and pulsed laser deposition using the assistance of a vapor phase surfactant. In both cases, surfactant incorporation enabled layer-by-layer growth and a smooth terminal surface by stabilizing the {l_brace}111{r_brace} rocksalt facet. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100 Multiplication-Sign reduction in leakage current density for the surfactant-assisted samples. These data verify numerous predictions regarding the role of H-termination in regulating the habit of rocksalt crystals.

  1. Anisotropy of two-photon absorption and free-carrier effect in nonpolar GaN

    SciTech Connect (OSTI)

    Fang, Yu; Zhou, Feng; Yang, Junyi; Wu, Xingzhi; Xiao, Zhengguo; Li, Zhongguo; Song, Yinglin

    2015-03-30

    We reported a systematic study about the anisotropic optical nonlinearities in bulk m-plane and a-plane GaN crystals by Z-scan and pump-probe with phase object methods under picosecond at 532 nm. The two-photon absorption coefficient, which was measured as a function of polarization angle, exhibited oscillation curves with a period of π/2, indicating a highly polarized optical third-order nonlinearity in both nonpolar GaN samples. Furthermore, free-carrier absorption revealed stronger hole-related absorption for E⊥c than for E//c probe polarization. In contrast, free-carrier refraction was found almost isotropic due to electron-related refraction in the isotropic conduction bands.

  2. Catalyst and its diameter dependent growth kinetics of CVD grown GaN nanowires

    SciTech Connect (OSTI)

    Samanta, Chandan [Department of Physics, Indian Institute of Technology Kanpur (India)] [Department of Physics, Indian Institute of Technology Kanpur (India); Chander, D. Sathish [Department of Physics, Indian Institute of Technology Kanpur (India) [Department of Physics, Indian Institute of Technology Kanpur (India); Department of Mechanical Engineering, Indian Institute of Technology Kanpur (India); Ramkumar, J. [Department of Mechanical Engineering, Indian Institute of Technology Kanpur (India)] [Department of Mechanical Engineering, Indian Institute of Technology Kanpur (India); Dhamodaran, S., E-mail: kdams2003@gmail.com [Department of Physics, Indian Institute of Technology Kanpur (India)

    2012-04-15

    Graphical abstract: GaN nanowires with controlled diameter and aspect ratio has been grown using a simple CVD technique. The growth kinetics of CVD grown nanowires investigated in detail for different catalysts and their diameters. A critical diameter important to distinguish the growth regimes has been discussed in detail. The results are important which demonstrates the growth of diameter and aspect ratio controlled GaN nanowires and also understand their growth kinetics. Highlights: Black-Right-Pointing-Pointer Controlled diameter and aspect ratio of GaN nanowires achieved in simple CVD reactor. Black-Right-Pointing-Pointer Nanowire growth kinetics for different catalyst and its diameters were understood. Black-Right-Pointing-Pointer Adatoms vapor pressure inside reactor plays a crucial role in growth kinetics. Black-Right-Pointing-Pointer Diffusion along nanowire sidewalls dominate for gold and nickel catalysts. Black-Right-Pointing-Pointer Gibbs-Thomson effect dominates for palladium catalyst. -- Abstract: GaN nanowires were grown using chemical vapor deposition with controlled aspect ratio. The catalyst and catalyst-diameter dependent growth kinetics is investigated in detail. We first discuss gold catalyst diameter dependent growth kinetics and subsequently compare with nickel and palladium catalyst. For different diameters of gold catalyst there was hardly any variation in the length of the nanowires but for other catalysts with different diameter a strong length variation of the nanowires was observed. We calculated the critical diameter dependence on adatoms pressure inside the reactor and inside the catalytic particle. This gives an increasing trend in critical diameter as per the order gold, nickel and palladium for the current set of experimental conditions. Based on the critical diameter, with gold and nickel catalyst the nanowire growth was understood to be governed by limited surface diffusion of adatoms and by Gibbs-Thomson effect for the palladium

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

    DOE Patents [OSTI]

    Armitage, Robert D.; Weber, Eicke R.

    2005-08-16

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

  4. Formation of manganese {delta}-doped atomic layer in wurtzite GaN

    SciTech Connect (OSTI)

    Shi Meng; Chinchore, Abhijit; Wang Kangkang; Mandru, Andrada-Oana; Liu Yinghao; Smith, Arthur R.

    2012-09-01

    We describe the formation of a {delta}-doped manganese layer embedded within c-plane wurtzite gallium nitride using a special molecular beam epitaxy growth process. Manganese is first deposited on the gallium-poor GaN (0001) surface, forming a {radical}(3) Multiplication-Sign {radical}(3)-R30 Degree-Sign reconstructed phase. This well-defined surface reconstruction is then nitrided using plasma nitridation, and gallium nitride is overgrown. The manganese content of the {radical}(3) Multiplication-Sign {radical}(3)-R30 Degree-Sign phase, namely one Mn per each {radical}(3) Multiplication-Sign {radical}(3)-R30 Degree-Sign unit cell, implies that the MnGaN alloy layer has a Mn concentration of up to 33%. The structure and chemical content of the surface are monitored beginning from the initial growth stage up through the overgrowth of 20 additional monolayers (MLs) of GaN. An exponential-like drop-off of the Mn signal with increasing GaN monolayers, as measured by Auger electron spectroscopy, indicates that the highly concentrated Mn layer remains at the {delta}-doped interface. A model of the resultant {delta}-doped structure is formulated based on the experimental data, and implications for possible spintronic applications are discussed.

  5. Analysis of the carbon-related 'blue' luminescence in GaN

    SciTech Connect (OSTI)

    Armitage, R.; Yang, Q.; Weber, E.R.

    2004-09-24

    The properties of a broad 2.86 eV photoluminescence band in carbon-doped GaN were studied as a function of C-doping level, temperature, and excitation density. The results are consistent with a C{sub Ga}-C{sub N} deep donor-deep acceptor recombination mechanism as proposed by Seager et al. For GaN:C grown by molecular-beam epitaxy (MBE) the 2.86 eV band is observed in Si co-doped layers exhibiting high n-type conductivity as well as in semi-insulating material. For low excitation density (4 W/cm{sup 2}) the 2.86 eV band intensity decreases as a function of cw-laser exposure time over a period of many minutes. The transient behavior is consistent with a model based on carrier diffusion and charge trapping-induced Coulomb barriers. The temperature dependence of the blue luminescence below 150 K was different for carbon-contaminated GaN grown by metalorganic vapor phase epitaxy (MOVPE) compared to C-doped MBE GaN.

  6. Theoretical and experimental study of dynamics of photoexcited carriers in GaN

    SciTech Connect (OSTI)

    Shishehchi, Sara; Bellotti, Enrico; Rudin, Sergey; Garrett, Gregory A.; Wraback, Michael

    2013-12-21

    We present a theoretical and experimental study of the sub-picosecond dynamics of photo-excited carriers in GaN. In the theoretical model, interaction with an external ultrafast laser pulse is treated coherently and to account for the scattering mechanisms and dephasing processes, a generalized Monte-Carlo simulation is used. The scattering mechanisms included are carrier interactions with polar optical phonons and acoustic phonons, and carrier-carrier Coulomb interactions. We study the effect of different scattering mechanisms on the carrier densities. In the case that the excitation energy satisfies the threshold for polar optical scattering, phonon contribution is the dominant process in relaxing the system, otherwise, carrier-carrier mechanism is dominant. Furthermore, we present the temperature and pulse power dependent normalized luminescence intensity. The results are presented over a range of temperatures, electric field, and excitation energy of the laser pulse. For comparison, we also report the experimental time-resolved photoluminescence studies on GaN samples. There is a good agreement between the simulation and experiment in normalized luminescence intensity results. Therefore, we show that we can explain the dynamics of the photo-excited carriers in GaN by including only carrier-carrier and carrier-phonon interactions and a relatively simple two-band electronic structure model.

  7. Vertical GaN power diodes with a bilayer edge termination

    SciTech Connect (OSTI)

    Dickerson, Jeramy R.; Allerman, Andrew A.; Bryant, Benjamin N.; Fischer, Arthur J.; King, Michael P.; Moseley, Michael W.; Armstrong, Andrew M.; Kaplar, Robert J.; Kizilyalli, Isik C.; Aktas, Ozgur; Wierer, Jr., Jonathan J.

    2015-12-07

    Vertical GaN power diodes with a bilayer edge termination (ET) are demonstrated. The GaN p-n junction is formed on a low threading dislocation defect density (104 - 105 cm-2) GaN substrate, and has a 15-μm-thick n-type drift layer with a free carrier concentration of 5 × 1015 cm-3. The ET structure is formed by N implantation into the p+-GaN epilayer just outside the p-type contact to create compensating defects. The implant defect profile may be approximated by a bilayer structure consisting of a fully compensated layer near the surface, followed by a 90% compensated (p) layer near the n-type drift region. These devices exhibit avalanche breakdown as high as 2.6 kV at room temperature. In addition simulations show that the ET created by implantation is an effective way to laterally distribute the electric field over a large area. This increases the voltage at which impact ionization occurs and leads to the observed higher breakdown voltages.

  8. Vertical GaN power diodes with a bilayer edge termination

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

    Dickerson, Jeramy R.; Allerman, Andrew A.; Bryant, Benjamin N.; Fischer, Arthur J.; King, Michael P.; Moseley, Michael W.; Armstrong, Andrew M.; Kaplar, Robert J.; Kizilyalli, Isik C.; Aktas, Ozgur; et al

    2015-12-07

    Vertical GaN power diodes with a bilayer edge termination (ET) are demonstrated. The GaN p-n junction is formed on a low threading dislocation defect density (104 - 105 cm-2) GaN substrate, and has a 15-μm-thick n-type drift layer with a free carrier concentration of 5 × 1015 cm-3. The ET structure is formed by N implantation into the p+-GaN epilayer just outside the p-type contact to create compensating defects. The implant defect profile may be approximated by a bilayer structure consisting of a fully compensated layer near the surface, followed by a 90% compensated (p) layer near the n-type driftmore » region. These devices exhibit avalanche breakdown as high as 2.6 kV at room temperature. In addition simulations show that the ET created by implantation is an effective way to laterally distribute the electric field over a large area. This increases the voltage at which impact ionization occurs and leads to the observed higher breakdown voltages.« less

  9. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2012-12-04

    The Order establishes facility and programmatic safety requirements for DOE and NNSA for nuclear safety design criteria, fire protection, criticality safety, natural phenomena hazards (NPH) mitigation, and System Engineer Program. Cancels DOE O 420.1B, DOE G 420.1-2 and DOE G 420.1-3.

  10. Nuclear Facilities

    Broader source: Energy.gov [DOE]

    The nuclear sites list and map shows how DOE nuclear operations are mostly divided between nuclear weapons stockpile maintenance, research and environmental cleanup. The operations are performed within several different facilities supporting nuclear reactor operations, nuclear research, weapons disassembly, maintenance and testing, hot cell operations, nuclear material storage and processing and waste disposal.

  11. Facility Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-10-13

    Establishes facility safety requirements related to: nuclear safety design, criticality safety, fire protection and natural phenomena hazards mitigation. Cancels DOE 5480.7A, DOE 5480.24, DOE 5480.28 and Division 13 of DOE 6430.1A. Canceled by DOE O 420.1A.

  12. Discovery of low-lying E1 and M1 strengths in {sup 232}Th

    SciTech Connect (OSTI)

    Adekola, A. S.; Hammond, S. L.; Hill, A.; Karwowski, H. J.; Angell, C. T.; Howell, C. R.; Kwan, E.; Kelley, J. H.

    2011-03-15

    Properties of low-energy dipole states in {sup 232}Th have been investigated with the nuclear resonance fluorescence technique. The present work used monoenergetic {gamma}-ray beams at energies of 2-4 MeV from the high-intensity {gamma}-ray source at Triangle Universities Nuclear Laboratory. Over 40 transitions corresponding to deexcitation to the ground state and first excited state were observed for the first time. Excitation energies, integrated cross sections, decay widths, branching ratios, and transition strengths for those states in {sup 232}Th were determined and compared with quasiparticle random-phase-approximation calculations. A large number of E1 transitions were observed for the first time in actinide nuclei with summed strength of 3.28(69)x10{sup -3} e{sup 2} fm{sup 2}. The observed summed M1 strength of 4.26(63){mu}{sub N}{sup 2} is in good agreement with the other actinides and with the systematics of the scissors mode in deformed rare-earth nuclei.

  13. Beam Test Facility

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

    Beam Test Facility Beam Test Facility Print Tuesday, 20 October 2009 09:36 Coming Soon

  14. Metro Methane Recovery Facility Biomass Facility | Open Energy...

    Open Energy Info (EERE)

    Methane Recovery Facility Biomass Facility Jump to: navigation, search Name Metro Methane Recovery Facility Biomass Facility Facility Metro Methane Recovery Facility Sector Biomass...

  15. Spectroscopic and magnetic properties of Mn doped GaN epitaxial films grown by plasma assisted molecular beam epitaxy

    SciTech Connect (OSTI)

    Vidyasagar, R.; Lin, Y.-T.; Tu, L.-W.

    2012-12-15

    Graphical abstract: We report here that micro-Raman scattering spectrum for Mn doped GaN thin film has displayed a new peak manifested at 578 cm{sup −1}, by which it is attributed to interior LVM originated by the incorporation of Mn ions in place of Ga sites. Mn doped GaN thin film also showed the typical negative magnetoresistance up to ∼50 K, revealing that the film showed magnetic ordering of spins below 50 K. Display Omitted Highlights: ► GaN and Mn doped GaN single phase wurtzite structures grown by PAMBE. ► The phase purity of the epilayers investigated by HRXRD, HRSEM and EDX. ► The red shift in near band edge emission has been observed using micro-PL. ► A new peak related LVM at 578 cm{sup −1} in micro-Raman scattering measurements confirmed Mn doped into GaN. ► Negative-magnetoresistance investigations have showed that the film has T{sub c} < 50 K. -- Abstract: Spectroscopic and magnetic properties of Mn doped GaN, and GaN epitaxial films have been investigated by employing micro-photoluminescence, micro-Raman, and temperature dependent magneto-resistance measurements. The HR-XRD profiles have shown that the epitaxial films are in hexagonal wurtzite structures. Morphology and composition of the films have been examined by field emission scanning electron microscopy, and energy-dispersive X-ray analysis. Micro-photoluminescence spectrum displayed a dominant near band edge emission at 362 nm, which is assigned to near band edge transition within the hexagonal structure of GaN. Raman scattering profiles showed a new vibrational mode at 578 cm{sup −1}, which is attributed to the vacancy-related local vibrational mode of Mn occupying the Ga site. Temperature dependent negative magnetoresistance measurements provide a direct evidence of magnetic ordering below 50 K for the Mn doped GaN thin film.

  16. Multicycle rapid thermal annealing optimization of Mg-implanted GaN: Evolution of surface, optical, and structural properties

    SciTech Connect (OSTI)

    Greenlee, Jordan D.; Feigelson, Boris N.; Anderson, Travis J.; Hite, Jennifer K.; Mastro, Michael A.; Eddy, Charles R.; Hobart, Karl D.; Kub, Francis J.; Tadjer, Marko J.

    2014-08-14

    The first step of a multi-cycle rapid thermal annealing process was systematically studied. The surface, structure, and optical properties of Mg implanted GaN thin films annealed at temperatures ranging from 900 to 1200?C were investigated by Raman spectroscopy, photoluminescence, UV-visible spectroscopy, atomic force microscopy, and Nomarski microscopy. The GaN thin films are capped with two layers of in-situ metal organic chemical vapor deposition -grown AlN and annealed in 24 bar of N{sub 2} overpressure to avoid GaN decomposition. The crystal quality of the GaN improves with increasing annealing temperature as confirmed by UV-visible spectroscopy and the full widths at half maximums of the E{sub 2} and A{sub 1} (LO) Raman modes. The crystal quality of films annealed above 1100?C exceeds the quality of the as-grown films. At 1200?C, Mg is optically activated, which is determined by photoluminescence measurements. However, at 1200?C, the GaN begins to decompose as evidenced by pit formation on the surface of the samples. Therefore, it was determined that the optimal temperature for the first step in a multi-cycle rapid thermal anneal process should be conducted at 1150?C due to crystal quality and surface morphology considerations.

  17. Utilization of native oxygen in Eu(RE)-doped GaN for enabling device compatibility in optoelectronic applications

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

    Mitchell, Brandon; Timmerman, D.; Poplawsky, Jonathan D.; Zhu, W.; Lee, D.; Wakamatsu, R.; Takatsu, J.; Matsuda, M.; Guo, Wei; Lorenz, K.; et al

    2016-01-04

    The detrimental influence of oxygen on the performance and reliability of V/III nitride based devices is well known. However, the influence of oxygen on the nature of the incorporation of other co-dopants, such as rare earth ions, has been largely overlooked in GaN. Here, we report the first comprehensive study of the critical role that oxygen has on Eu in GaN, as well as atomic scale observation of diffusion and local concentration of both atoms in the crystal lattice. We find that oxygen plays an integral role in the location, stability, and local defect structure around the Eu ions thatmore » were doped into the GaN host. Although the availability of oxygen is essential for these properties, it renders the material incompatible with GaN-based devices. However, the utilization of the normally occurring oxygen in GaN is promoted through structural manipulation, reducing its concentration by 2 orders of magnitude, while maintaining both the material quality and the favorable optical properties of the Eu ions. Furthermore, these findings open the way for full integration of RE dopants for optoelectronic functionalities in the existing GaN platform.« less

  18. Facility Type!

    Office of Legacy Management (LM)

    ITY: --&L~ ----------- srct-r~ -----------~------~------- if yee, date contacted ------------- cl Facility Type! i I 0 Theoretical Studies Cl Sample 84 Analysis ] Production 1 Diepasal/Storage 'YPE OF CONTRACT .--------------- 1 Prime J Subcontract&- 1 Purchase Order rl i '1 ! Other information (i.e., ---------~---~--~-------- :ontrait/Pirchaee Order # , I C -qXlJ- --~-------~~-------~~~~~~ I I ~~~---~~~~~~~T~~~ FONTRACTING PERIODi IWNERSHIP: ,I 1 AECIMED AECMED GOVT GOUT &NTtiAC+OR

  19. Research Facilities | NREL

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

    Research Facilities Our state-of-the-art facilities are available to industry entrepreneurs, engineers, scientists, and universities for researching and developing their energy technologies. Our researchers and technicians who operate these labs and facilities are ready to work with you and share their expertise. Alphabetical Listings Laboratories Test and User Facilities Popular Facilities Energy Systems Integration Facility Integrated Biorefinery Research Facility Process Development

  20. Ab initio study on noncompensated CrO codoping of GaN for enhanced solar energy conversion

    SciTech Connect (OSTI)

    Pan, Hui; Gu, Baohua; Eres, Gyula; Zhang, Zhenyu

    2010-03-01

    We describe a novel photocatalyst obtained by codoping GaN with CrO, according to a new "noncompensated" codoping concept based on first-principles calculations. The approach enables controllable narrowing of the GaN band gap with significantly enhanced carrier mobility and photocatalytic activity in the visible light region and thus offers immense potential for application in solar energy conversion, water splitting, and a variety of solar-assisted photocatalysis. Our calculations indicate that the formation energy for the cation doping is greatly reduced by noncompensated codoping with an anion. Although Cr doping alone can split the band gap with the formation of an intermediate band, the mobility is low due to carrier trapping by the localized states. The first-principles calculations also demonstrate that CrO codoping of GaN shifts the Fermi level into the conduction band resulting in high carrier density and mobility.

  1. Properties of radio-frequency-sputter-deposited GaN films in a nitrogen/hydrogen mixed gas

    SciTech Connect (OSTI)

    Miyazaki, Takayuki; Takada, Kouhei; Adachi, Sadao; Ohtsuka, Kohji

    2005-05-01

    GaN films have been deposited by reactive sputtering in nitrogen gas at pressures from 0.08 to 2.70 Pa with and without the addition of hydrogen gas. X-ray diffraction (XRD), Fourier transform infrared (FTIR), optical absorption, and photoluminescence (PL) spectroscopy have been used to characterize the sputter-deposited GaN films. The XRD pattern reveals that the GaN films deposited in nitrogen gas at pressures lower than 0.53 Pa are polycrystals with the (0001) texture ({alpha}-GaN), while those deposited at or above 1.07 Pa display mixed crystalline orientations or an amorphous-like nature. The GaN:H films deposited in nitrogen/hydrogen mixed gas, on the other hand, show an amorphous or amorphous-like nature. The FTIR spectra indicate that the GaN:H films show peaks arising from hydrogen-related bonds at {approx}1000 and {approx}3200 cm{sup -1}, in addition to the GaN absorption band at {approx}555 cm{sup -1}. The optical absorption spectra at 300 K indicate the fundamental absorption edges at {approx}3.38 and {approx}3.7 eV for the highly oriented {alpha}-GaN and amorphous GaN:H films, respectively. PL emission has been observed from sputter-deposited {alpha}-GaN films at temperatures below 100 K. The GaN:H films also show strong band-edge and donor-acceptor pair emissions. The PL emission in the GaN:H film may arise from crystalline GaN particles embedded in the amorphous GaN matrix.

  2. Fundamental Bulk/Surface Structure Photoactivity Relationships of Supported (Rh2-yCryO3)/GaN Photocatalysts

    SciTech Connect (OSTI)

    Phivilay, Somphonh; Roberts, Charles; Puretzky, Alexander A; Domen, Kazunari Domen; Wachs, Israel

    2013-01-01

    ABSTRACT. The supported (Rh2-yCryO3)/GaN photocatalyst was examined as a model nitride photocatalyst system to assist in the development of fundamental structure photoactivity relationships for UV activated water splitting. Surface characterization of the outermost surface layers by High Sensitivity-LEIS and High Resolution-XPS revealed for the first time that the GaN support consists of a GaOx outermost surface layer and a thin film of GaOxNy in the surface region. HR-XPS also demonstrates that the supported (Rh2-yCryO3) mixed oxide nanoparticles (NPs) exclusively consist of Cr+3 and Rh+3 cations and are surface enriched for the supported (Rh2-yCryO3)/GaN photocatalyst. Bulk analysis by Raman and UV-vis spectroscopy show that the bulk molecular and electronic structures, respectively, of the GaN support are not perturbed by the deposition of the (Rh2-yCryO3) mixed oxide NPs. The function of the GaN bulk lattice is to generate photoexcited electrons/holes, with the electrons harnessed by the surface Rh+3 sites for evolution of H2 and the holes trapped at the Ga oxide/oxynitride surface sites for splitting of water and evolving O2. These new structure-photoactivity relationships for supported (Rh2-yCryO3)/GaN also extend to the best performing visible light activated supported (Rh2-yCryO3)/(Ga1-xZnx)(N1-xOx) photocatalyst.

  3. NREL: Research Facilities - Webmaster

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

    Your name: Your email address: Your message: Send Message Printable Version Research Facilities Home Laboratories Test & User Facilities Laboratories & Facilities by Technology...

  4. Facilities | Bioenergy | NREL

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

    Facilities At NREL's state-of-the-art bioenergy research facilities, researchers design ... facility to develop, test, evaluate, and demonstrate bioenergy processes and technologies. ...

  5. Research Facility,

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

    Delivering the Data As a general condition for use of the ARM Climate Research Facility, users are required to include their data in the ARM Data Archive. All data acquired must be of sufficient quality to be useful and must be documented such that users will be able to clearly understand the meaning and organization of the data. Final, quality-assured data sets are stored in the Data Archive and are freely accessible to the general scientific community. Upon conclusion of the field campaign,

  6. Electroreflectance study of the effect of {gamma} radiation on the optical properties of epitaxial GaN films

    SciTech Connect (OSTI)

    Belyaev, A. E.; Klyui, N. I. Konakova, R. V.; Lukyanov, A. N.; Danilchenko, B. A.; Sveshnikov, J. N.; Klyui, A. N.

    2012-03-15

    Experimental data on the electroreflectance spectra of {gamma}-irradiated epitaxial GaN films on sapphire are reported. The irradiation doses are 10{sup 5}-2 Multiplication-Sign 10{sup 6} rad. The theoretical electroreflectance spectra calculated on the basis of a model of three types of transitions are in agreement with experimental data with reasonable accuracy. The energies and broadenings of the transitions derived in the context of the model give grounds to infer that, in the GaN films, there are internal stresses dependent on the {gamma}-irradiation dose.

  7. Harrisburg Facility Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    2006 Database Retrieved from "http:en.openei.orgwindex.php?titleHarrisburgFacilityBiomassFacility&oldid397545" Feedback Contact needs updating Image needs updating...

  8. Brookhaven Facility Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    2006 Database Retrieved from "http:en.openei.orgwindex.php?titleBrookhavenFacilityBiomassFacility&oldid397235" Feedback Contact needs updating Image needs updating...

  9. Support - Facilities - Radiation Effects Facility / Cyclotron...

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

    During experiments at the Radiation Effects Facility users are assisted by the experienced ... shops are available to the users of the Radiation Effects Facility for design, ...

  10. Radiation Effects Facility - Facilities - Cyclotron Institute

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

    Radiation Effects Facility Typical DUT(device under test) set-up at the end of the Radiation Effects beamline. The Radiation Effects Facility is available for commercial, ...

  11. Nanoscale size dependence parameters on lattice thermal conductivity of Wurtzite GaN nanowires

    SciTech Connect (OSTI)

    Mamand, S.M.; Omar, M.S.; Muhammad, A.J.

    2012-05-15

    Graphical abstract: Temperature dependence of calculated lattice thermal conductivity of Wurtzite GaN nanowires. Highlights: Black-Right-Pointing-Pointer A modified Callaway model is used to calculate lattice thermal conductivity of Wurtzite GaN nanowires. Black-Right-Pointing-Pointer A direct method is used to calculate phonon group velocity for these nanowires. Black-Right-Pointing-Pointer 3-Gruneisen parameter, surface roughness, and dislocations are successfully investigated. Black-Right-Pointing-Pointer Dislocation densities are decreases with the decrease of wires diameter. -- Abstract: A detailed calculation of lattice thermal conductivity of freestanding Wurtzite GaN nanowires with diameter ranging from 97 to 160 nm in the temperature range 2-300 K, was performed using a modified Callaway model. Both longitudinal and transverse modes are taken into account explicitly in the model. A method is used to calculate the Debye and phonon group velocities for different nanowire diameters from their related melting points. Effect of Gruneisen parameter, surface roughness, and dislocations as structure dependent parameters are successfully used to correlate the calculated values of lattice thermal conductivity to that of the experimentally measured curves. It was observed that Gruneisen parameter will decrease with decreasing nanowire diameters. Scattering of phonons is assumed to be by nanowire boundaries, imperfections, dislocations, electrons, and other phonons via both normal and Umklapp processes. Phonon confinement and size effects as well as the role of dislocation in limiting thermal conductivity are investigated. At high temperatures and for dislocation densities greater than 10{sup 14} m{sup -2} the lattice thermal conductivity would be limited by dislocation density, but for dislocation densities less than 10{sup 14} m{sup -2}, lattice thermal conductivity would be independent of that.

  12. Mechanism of the GaN LED efficiency falloff with increasing current

    SciTech Connect (OSTI)

    Bochkareva, N. I.; Voronenkov, V. V.; Gorbunov, R. I.; Zubrilov, A. S.; Lelikov, Y. S.; Latyshev, F. E.; Rebane, Y. T.; Tsyuk, A. I.; Shreter, Y. G.

    2010-06-15

    The quantum efficiency of GaN LED structures has been studied at various temperatures and biases. It was found that an efficiency falloff is observed with increasing current density and, simultaneously, the tunnel component of the current through the LED grows and the quasi-Fermi levels reach the mobility edge in the InGaN active layer. It is shown that the internal quantum efficiency falloff with increasing current density is due to the carrier leakage from the quantum well as a result of tunnel transitions from its band-tail states to local defect-related energy levels within the energy gaps of the barrier layers.

  13. Impact of the GaN nanowire polarity on energy harvesting

    SciTech Connect (OSTI)

    Gogneau, Noelle Galopin, Elisabeth; Guilet, Stephane; Travers, Laurent; Harmand, Jean-Christophe; Chrétien, Pascal; Houzé, Frédéric

    2014-05-26

    We investigate the piezoelectric generation properties of GaN nanowires (NWs) by atomic force microscopy equipped with a Resiscope module for electrical measurements. By correlating the topography profile of the NWs with the recorded voltage peaks generated by these nanostructures in response to their deformation, we demonstrate the influence of their polarity on the rectifying behavior of the Schottky diode formed between the NWs and the electrode of measurement. These results establish that the piezo-generation mechanism crucially depends on the structural characteristics of the NWs.

  14. Kent County Waste to Energy Facility Biomass Facility | Open...

    Open Energy Info (EERE)

    County Waste to Energy Facility Biomass Facility Jump to: navigation, search Name Kent County Waste to Energy Facility Biomass Facility Facility Kent County Waste to Energy...

  15. Stockton Regional Water Control Facility Biomass Facility | Open...

    Open Energy Info (EERE)

    Stockton Regional Water Control Facility Biomass Facility Jump to: navigation, search Name Stockton Regional Water Control Facility Biomass Facility Facility Stockton Regional...

  16. ARM - Facility News Article

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

    December 4, 2010 [Facility News] Request for Proposals Now Open Bookmark and Share The ARM Climate Research Facility is now accepting applications for use of the ARM mobile facilities, aerial facility, and fixed sites. Proposals are welcome from all members of the scientific community for conducting field campaigns and scientific research using the ARM Facility. Facility availability is as follows: ARM Mobile Facility 2 (AMF2) available FY2013 ARM Mobile Facility 1 (AMF1) available March 2015

  17. Manufacturing Demonstration Facility

    Energy Savers [EERE]

    of Energy Manufacturing Demonstration Facility DOE Advanced Manufacturing Office Merit Review Craig Blue Director, Manufacturing Demonstration Facility Energy and ...

  18. Enhanced UV detection by non-polar epitaxial GaN films

    SciTech Connect (OSTI)

    Mukundan, Shruti; Chandan, Greeshma; Mohan, Lokesh; Krupanidhi, S. B.; Roul, Basanta; Shetty, Arjun

    2015-12-15

    Nonpolar a-GaN (11-20) epilayers were grown on r-plane (1-102) sapphire substrates using plasma assisted molecular beam epitaxy. High resolution x-ray diffractometer confirmed the orientation of the grown film. Effect of the Ga/N ratio on the morphology and strain of a-GaN epilayers was compared and the best condition was obtained for the nitrogen flow of 1 sccm. Atomic force microscopy was used to analyze the surface morphology while the strain in the film was quantitatively measured using Raman spectroscopy and qualitatively analyzed by reciprocal space mapping technique. UV photo response of a-GaN film was measured after fabricating a metal-semiconductor-metal structure over the film with gold metal. The external quantum efficiency of the photodetectors fabricated in the (0002) polar and (11-20) nonpolar growth directions were compared in terms of responsivity and nonpolar GaN showed the best sensitivity at the cost of comparatively slow response time.

  19. Surfactant assisted growth of MgO films on GaN

    SciTech Connect (OSTI)

    Paisley, Elisibeth A.; Shelton, T C; Mita, S; Gaddy, Brian E.; Irving, D L; Christen, Hans M; Sitar, Z; Biegalski, Michael D; Maria, Jon Paul

    2012-01-01

    Thin epitaxial films of <111> oriented MgO on [0001]-oriented GaN were grown by molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) using the assistance of a vapor phase surfactant. In both cases, surfactant incorporation enabled layer-by-layer growth and a smooth terminal surface due to stabilizing the {111} rocksalt facet. MBE growth of MgO in water terminates after several monolayers, and is attributed to saturation of surface active sites needed to facilitate the Mg oxidation reaction. MgO films prepared by PLD grow continuously, this occurs due to the presence of excited oxidizing species in the laser plasma eliminate the need for catalytic surface sites. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly two order of magnitude reduction in leakage current density for the smoother surfactant-assisted samples. Collectively, these data verify numerous predictions and calculations regarding the role of H-termination in regulating the habit of MgO crystals.

  20. The effect of N-polar GaN domains as Ohmic contacts

    SciTech Connect (OSTI)

    Xie, J.; Mita, S.; Collazo, R.; Rice, A.; Tweedie, J.; Sitar, Z.

    2010-09-20

    Transfer line method measurements revealed that if the Ohmic contact regions were replaced by N-polar GaN, the contact resistance could be reduced from 0.71 {Omega} mm (or {rho}{sub c}=4x10{sup -6} {Omega} cm{sup 2}) to 0.24 {Omega} mm for a {approx}200 nm thick Si-doped GaN layer. The reduction in contact resistance was largely due to the {approx}10{sup 19} cm{sup -3} free carriers in N-polar source/drain regions as measured by Hall effect. Secondary ion mass spectroscopy confirmed that oxygen doping in the N-polar region was more than three orders of magnitude greater than that in the Ga-polar region that was explained by the large difference in the adsorption energy for oxygen ({approx}1.3 eV/atom) between the N- and Ga-polar surfaces during the metalorganic chemical vapor deposition.

  1. Excitation mechanisms of Er optical centers in GaN epilayers

    SciTech Connect (OSTI)

    George, D. K.; Hawkins, M. D.; McLaren, M.; Vinh, N. Q.; Jiang, H. X.; Lin, J. Y.; Zavada, J. M.

    2015-10-26

    We report direct evidence of two mechanisms responsible for the excitation of optically active Er{sup 3+} ions in GaN epilayers grown by metal-organic chemical vapor deposition. These mechanisms, resonant excitation via the higher-lying inner 4f shell transitions and band-to-band excitation of the semiconductor host, lead to narrow emission lines from isolated and the defect-related Er optical centers. However, these centers have different photoluminescence spectra, local defect environments, decay dynamics, and excitation cross sections. The photoluminescence at 1.54 μm from the isolated Er optical center which can be excited by either mechanism has the same decay dynamics, but possesses a much higher excitation cross-section under band-to-band excitation. In contrast, the photoluminescence at 1.54 μm from the defect-related Er optical center can only be observed through band-to-band excitation but has the largest excitation cross-section. These results explain the difficulty in achieving gain in Er doped GaN and indicate approaches for realization of optical amplification, and possibly lasing, at room temperature.

  2. Growth modes of InN(000-1) on GaN buffer layers on sapphire

    SciTech Connect (OSTI)

    Liu, Bing; Kitajima, Takeshi; Chen, Dongxue; Leone, Stephen R.

    2005-01-24

    In this work, using atomic force microscopy and scanning tunneling microscopy, we study the surface morphologies of epitaxial InN films grown by plasma-assisted molecular beam epitaxy with intervening GaN buffer layers on sapphire substrates. On smooth GaN buffer layers, nucleation and evolution of three-dimensional InN islands at various coverages and growth temperatures are investigated. The shapes of the InN islands are observed to be predominantly mesa-like with large flat (000-1) tops, which suggests a possible role of indium as a surfactant. Rough GaN buffer layers composed of dense small GaN islands are found to significantly improve uniform InN wetting of the substrates, on which atomically smooth InN films are obtained that show the characteristics of step-flow growth. Scanning tunneling microscopy imaging reveals the defect-mediated surface morphology of smooth InN films, including surface terminations of screw dislocations and a high density of shallow surface pits with depths less than 0.3 nm. The mechanisms of the three-dimensional island size and shape evolution and formation of defects on smooth surfaces are considered.

  3. Impact of defects on the electrical transport, optical properties and failure mechanisms of GaN nanowires.

    SciTech Connect (OSTI)

    Armstrong, Andrew M.; Aubry, Sylvie; Shaner, Eric Arthur; Siegal, Michael P.; Li, Qiming; Jones, Reese E.; Westover, Tyler; Wang, George T.; Zhou, Xiao Wang; Talin, Albert Alec; Bogart, Katherine Huderle Andersen; Harris, C. Thomas; Huang, Jian Yu

    2010-09-01

    We present the results of a three year LDRD project that focused on understanding the impact of defects on the electrical, optical and thermal properties of GaN-based nanowires (NWs). We describe the development and application of a host of experimental techniques to quantify and understand the physics of defects and thermal transport in GaN NWs. We also present the development of analytical models and computational studies of thermal conductivity in GaN NWs. Finally, we present an atomistic model for GaN NW electrical breakdown supported with experimental evidence. GaN-based nanowires are attractive for applications requiring compact, high-current density devices such as ultraviolet laser arrays. Understanding GaN nanowire failure at high-current density is crucial to developing nanowire (NW) devices. Nanowire device failure is likely more complex than thin film due to the prominence of surface effects and enhanced interaction among point defects. Understanding the impact of surfaces and point defects on nanowire thermal and electrical transport is the first step toward rational control and mitigation of device failure mechanisms. However, investigating defects in GaN NWs is extremely challenging because conventional defect spectroscopy techniques are unsuitable for wide-bandgap nanostructures. To understand NW breakdown, the influence of pre-existing and emergent defects during high current stress on NW properties will be investigated. Acute sensitivity of NW thermal conductivity to point-defect density is expected due to the lack of threading dislocation (TD) gettering sites, and enhanced phonon-surface scattering further inhibits thermal transport. Excess defect creation during Joule heating could further degrade thermal conductivity, producing a viscous cycle culminating in catastrophic breakdown. To investigate these issues, a unique combination of electron microscopy, scanning luminescence and photoconductivity implemented at the nanoscale will be used in

  4. Sandia National Laboratories: Facilities

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

    Facilities Bioscience Computing and Information Science Electromagnetics Facilities Electromagnetic Environments Simulator (EMES) Mode Stirred Chamber Lightning Facility Electrostatic Discharge (ESD) Laboratory Other Facilities and Capabilities Programs & Capabilities Partnership Opportunities EM News & Reports Contact Information Engineering Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research Facilities

  5. Tellurium n-type doping of highly mismatched amorphous GaN1-xAsx alloys in plasma-assisted molecular beam epitaxy

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

    Novikov, S. V.; Ting, M.; Yu, K. M.; Sarney, W. L.; Martin, R. W.; Svensson, S. P.; Walukiewicz, W.; Foxon, C. T.

    2014-10-01

    In this paper we report our study on n-type Te doping of amorphous GaN1-xAsx layers grown by plasma-assisted molecular beam epitaxy. We have used a low temperature PbTe source as a source of tellurium. Reproducible and uniform tellurium incorporation in amorphous GaN1-xAsx layers has been successfully achieved with a maximum Te concentration of 9×10²⁰ cm⁻³. Tellurium incorporation resulted in n-doping of GaN1-xAsx layers with Hall carrier concentrations up to 3×10¹⁹ cm⁻³ and mobilities of ~1 cm²/V s. The optimal growth temperature window for efficient Te doping of the amorphous GaN1-xAsx layers has been determined.

  6. CMI Unique Facility: Ferromagnetic Materials Characterization Facility |

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

    Critical Materials Institute Ferromagnetic Materials Characterization Facility The Ferromagnetic Materials Characterization Facility is one of more than a dozen unique facilities developed by the Critical Materials Institute, an Energy Innovation Hub of the U.S. Department of Energy. CMI ferromagnetic materials characterization facility at The Ames Laboratory. In the search for substitute materials to replace rare earths in permanent magnets, whenever promising materials are identified,

  7. Uranium Processing Facility | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Uranium Processing Facility

  8. Effect of ZnO seed layer on the morphology and optical properties of ZnO nanorods grown on GaN buffer layers

    SciTech Connect (OSTI)

    Nandi, R. Mohan, S. Major, S. S.; Srinivasa, R. S.

    2014-04-24

    ZnO nanorods were grown by chemical bath deposition on sputtered, polycrystalline GaN buffer layers with and without ZnO seed layer. Scanning electron microscopy and X-ray diffraction show that the ZnO nanorods on GaN buffer layers are not vertically well aligned. Photoluminescence spectrum of ZnO nanorods grown on GaN buffer layer, however exhibits a much stronger near-band-edge emission and negligible defect emission, compared to the nanorods grown on ZnO buffer layer. These features are attributed to gallium incorporation at the ZnO-GaN interface. The introduction of a thin (25 nm) ZnO seed layer on GaN buffer layer significantly improves the morphology and vertical alignment of ZnO-NRs without sacrificing the high optical quality of ZnO nanorods on GaN buffer layer. The presence of a thick (200 nm) ZnO seed layer completely masks the effect of the underlying GaN buffer layer on the morphology and optical properties of nanorods.

  9. Highly c-axis oriented GaN films grown on free-standing diamond substrates for high-power devices

    SciTech Connect (OSTI)

    Zhang, D. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Bian, J.M., E-mail: jmbian@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Qin, F.W.; Wang, J.; Pan, L. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Zhao, J.M. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Zhao, Y.; Bai, Y.Z. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Du, G.T. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2011-10-15

    Highlights: {yields} GaN films are deposited on diamond substrates by ECR-PEMOCVD. {yields} Influence of deposition temperature on the properties of samples is investigated. {yields} Properties of GaN films are dependent on the deposition temperature. -- Abstract: GaN films with highly c-axis preferred orientation are deposited on free-standing thick diamond films by low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition (ECR-PEMOCVD). The TMGa and N{sub 2} are applied as precursors of Ga and N, respectively. The quality of as-grown GaN films are systematically investigated as a function of deposition temperature by means of X-ray diffraction (XRD) analysis, Hall Effect measurement (HL), room temperature photoluminescence (PL) and atomic force microscopy (AFM). The results show that the dense and uniformed GaN films with highly c-axis preferred orientation are successfully achieved on free-standing diamond substrates under optimized deposition temperature of 400 {sup o}C, and the room temperature PL spectra of the optimized GaN film show a intense ultraviolet near band edge emission and a weak yellow luminescence. The obtained GaN/diamond structure has great potential for the development of high-power semiconductor devices due to its excellent heat dissipation nature.

  10. McKay Bay Facility Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    Biomass Facility Facility McKay Bay Facility Sector Biomass Facility Type Municipal Solid Waste Location Hillsborough County, Florida Coordinates 27.9903597, -82.3017728...

  11. Facilities | Argonne National Laboratory

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

    Facilities Some of the nation's most powerful and sophisticated facilities for energy research Argonne National Laboratory is home to some of the nation's most powerful and sophisticated research facilities. As a U.S. Department of Energy national laboratory, Argonne offers access to the facilities listed below through a variety of arrangements. Advanced Powertrain Research Facility Center for Transportation Research Materials Engineering Research Facility Distributed Energy Research Center

  12. National User Facilities

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

    National User Facilities Our Vision National User Facilities Research Areas In Focus Global Solutions ⇒ Navigate Section Our Vision National User Facilities Research Areas In Focus Global Solutions Berkeley Lab's User Facilities-Engines of Discovery Berkeley Lab's User Facilities provide state-of-the-art resources for scientists across the nation and around the world. About 10,000 researchers a year use these facilities, representing nearly one third of the total for all Department of Energy

  13. Demonstration of forward inter-band tunneling in GaN by polarization engineering

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram; Park, Pil Sung; Rajan, Siddharth

    2011-12-05

    We report on the design, fabrication, and characterization of GaN interband tunnel junction showing forward tunneling characteristics. We have achieved very high forward tunneling currents (153 mA/cm{sup 2} at 10 mV, and 17.7 A/cm{sup 2} peak current) in polarization-engineered GaN/InGaN/GaN heterojunction diodes grown by plasma assisted molecular beam epitaxy. We also report the observation of repeatable negative differential resistance in interband III-Nitride tunnel junctions, with peak-valley current ratio of 4 at room temperature. The forward current density achieved in this work meets the typical current drive requirements of a multi-junction solar cell.

  14. Resonant energy transfer between Eu luminescent sites and their local geometry in GaN

    SciTech Connect (OSTI)

    Timmerman, Dolf; Wakamatsu, Ryuta; Tanaka, Kazuteru; Lee, Dong-gun; Koizumi, Atsushi; Fujiwara, Yasufumi

    2015-10-12

    Eu-doped GaN is a solid state material with promising features for quantum manipulation. In this study, we investigate the population dynamics of Eu in ions in this system by resonant excitation. From differences in the emission related to transitions between the {sup 5}D{sub 0} and {sup 7}F{sub 2} manifold in the Eu ions, we can distinguish different luminescence sites and observe that a resonant energy transfer takes place between two of these sites which are in proximity of each other. The time constants related to this energy transfer are on the order of 100 μs. By using different substrates, the energy transfer efficiency could be strongly altered, and it is demonstrated that the coupling between ions has an out-of-plane character. Based on these results, a microscopic model of this combined center is presented.

  15. Influence of the adatom diffusion on selective growth of GaN nanowire regular arrays

    SciTech Connect (OSTI)

    Gotschke, T.; Schumann, T.; Limbach, F.; Calarco, R.; Stoica, T.

    2011-03-07

    Molecular beam epitaxy (MBE) on patterned Si/AlN/Si(111) substrates was used to obtain regular arrays of uniform-size GaN nanowires (NWs). The silicon top layer has been patterned with e-beam lithography, resulting in uniform arrays of holes with different diameters (d{sub h}) and periods (P). While the NW length is almost insensitive to the array parameters, the diameter increases significantly with d{sub h} and P till it saturates at P values higher than 800 nm. A diffusion induced model was used to explain the experimental results with an effective diffusion length of the adatoms on the Si, estimated to be about 400 nm.

  16. Monolithic single GaN nanowire laser with photonic crystal microcavity on silicon

    SciTech Connect (OSTI)

    Heo, Junseok; Guo Wei; Bhattacharya, Pallab

    2011-01-10

    Optically pumped lasing at room temperature in a silicon based monolithic single GaN nanowire with a two-dimensional photonic crystal microcavity is demonstrated. Catalyst-free nanowires with low density ({approx}10{sup 8} cm{sup -2}) are grown on Si by plasma-assisted molecular beam epitaxy. High resolution transmission electron microscopy images reveal that the nanowires are of wurtzite structure and they have no observable defects. A single nanowire laser fabricated on Si is characterized by a lasing transition at {lambda}=371.3 nm with a linewidth of 0.55 nm. The threshold is observed at a pump power density of {approx}120 kW/cm{sup 2} and the spontaneous emission factor {beta} is estimated to be 0.08.

  17. ARM Climate Research Facility

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

    3 ARM Climate Research Facility Quarterly Ingest Status Report A Koontz C Sivaraman ... DOESC-ARM-14-003 ARM Climate Research Facility Quarterly Ingest Report First Quarter: ...

  18. ARM Climate Research Facility

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

    8 ARM Climate Research Facility Quarterly Ingest Status Report A Koontz C Sivaraman ... DOESC-ARM-14-028 ARM Climate Research Facility Quarterly Ingest Report Fourth Quarter: ...

  19. ARM Climate Research Facility

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

    3 ARM Climate Research Facility Quarterly Ingest Status Report A Koontz C Sivaraman ... DOESC-ARM-15-003 ARM Climate Research Facility Quarterly Ingest Report First Quarter: ...

  20. ARM Climate Research Facility

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

    DOESC-ARM-15-019 ARM Climate Research Facility Quarterly Value-Added Product Report ... implemented by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. ...

  1. ARM Climate Research Facility

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

    DOESC-ARM-15-020 ARM Climate Research Facility Quarterly Ingest Report Second Quarter: ... maintained by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. ...

  2. ARM Climate Research Facility

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

    ARM Climate Research Facility Quarterly Ingest Status Report A Koontz C Sivaraman April ... DOESC-ARM-14-014 ARM Climate Research Facility Quarterly Ingest Report Second Quarter: ...

  3. ARM - NSA Barrow Facility

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

    Barrow Facility NSA Related Links Facilities and Instruments Barrow Atqasuk Oliktok Point (AMF3) ES&H Guidance Statement Operations Science Field Campaigns Visiting the Site NSA...

  4. ARM - Facility News Article

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

    30, 2009 Facility News ARM Aerial Facility Leads International Discussions on Aircraft Research Bookmark and Share Five research aircraft participated in the VAMOS...

  5. ARM - Facility News Article

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

    (BERAC) published findings and recommendations from their assessment of the effectiveness of ARM Climate Research Facility as a national scientific user facility. Based on...

  6. NREL: Wind Research - Facilities

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

    support the growth of wind energy development across the United States. National Wind Technology Center Facilities Our facilities are contained within a 305-acre area that...

  7. NREL: Biomass Research - Facilities

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

    Facilities At NREL's state-of-the-art biomass research facilities, researchers design and optimize processes to convert renewable biomass feedstocks into transportation fuels and...

  8. ARM - Facility News Article

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

    Interferometers Compared for ARM Mobile Facility Deployment in China Bookmark and Share ... Mobile Facility in 2008 for a field campaign to study Aerosol Indirect Effects in China. ...

  9. ARM - Facility News Article

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

    January 11, 2007 Facility News ARM Mobile Facility Moves to China in 2008 for Study of ... China generates exceptionally high amounts of aerosol particles whose influence on the ...

  10. Central Receiver Test Facility

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

    Receiver Test Facility - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us ... Applications National Solar Thermal Test Facility Nuclear Energy Systems ...

  11. ARM - Facility News Article

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

    13, 2014 Facility News Characterizing Ice Nuclei Over Southern Great Plains Bookmark and Share Placed on the upper platform of the SGP Guest Instrument Facility, this filter...

  12. ARM - Facility News Article

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

    facility use by total visitor days and facility to track actual visitors and active user research computer accounts. Historical data show an apparent relationship between the...

  13. ARM - SGP Radiometric Calibration Facility

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

    Radiometric Calibration Facility SGP Related Links Virtual Tour Facilities and Instruments Central Facility Boundary Facility Extended Facility Intermediate Facility Radiometric Calibration Facility Geographic Information ES&H Guidance Statement Operations Science Field Campaigns Visiting the Site Summer Training SGP Fact Sheet Images Information for Guest Scientists Contacts SGP Radiometric Calibration Facility The Radiometric Calibration Facility (RCF) provides shortwave radiometer

  14. Guide to research facilities

    SciTech Connect (OSTI)

    Not Available

    1993-06-01

    This Guide provides information on facilities at US Department of Energy (DOE) and other government laboratories that focus on research and development of energy efficiency and renewable energy technologies. These laboratories have opened these facilities to outside users within the scientific community to encourage cooperation between the laboratories and the private sector. The Guide features two types of facilities: designated user facilities and other research facilities. Designated user facilities are one-of-a-kind DOE facilities that are staffed by personnel with unparalleled expertise and that contain sophisticated equipment. Other research facilities are facilities at DOE and other government laboratories that provide sophisticated equipment, testing areas, or processes that may not be available at private facilities. Each facility listing includes the name and phone number of someone you can call for more information.

  15. The E2/M1 mixing ratio in the excitation of the {Delta} from polarized photo-reactions

    SciTech Connect (OSTI)

    The LEGS Collaboration

    1993-12-01

    In constituent quark models, a tensor interaction, mixing quark spins with their relative motion, is introduced to reproduce the observed baryon spectrum. This has a consequence completely analogous to the nuclear tensor force between the n and p in deuterium. A D state component is mixed into what would otherwise be a purely S-wave object. The D-wave component breaks spherical symmetry, resulting in a non-vanishing matrix element for the nucleon and a static quadrupole moment and deformation for its first excited state, the {Delta} resonance, at {approximately}325 MeV. The magnitude and sign of this D-state component are quite sensitive to the internal structure of the proton and have been of great interest in recent years. The intrinsic deformation of the spin 1/2 nucleon cannot be observed directly; it must be inferred from transition amplitudes such as N {yields} {Delta}. In a spherical bag model, the {Delta} is viewed as a pure quark-spin-flip transition proceeding only through M1 excitation. If there are D-state admixtures in the ground state of the nucleon and/or {Delta}, quadrupole excitation, in addition to spin-flip M1, is also allowed. The problem is to evaluate the relative magnitude of this E2 excitation in the presence of the dominant M1 transition. A variety of models predict this mixing ratio to be quite small, anywhere from {minus}0.9% to {minus}6%, so that a high degree of precision is demanded of experiment.

  16. Efficient Switches for Solar Power Conversion: Four Quadrant GaN Switch Enabled Three Phase Grid-Tied Microinverters

    SciTech Connect (OSTI)

    2012-02-13

    Solar ADEPT Project: Transphorm is developing power switches for new types of inverters that improve the efficiency and reliability of converting energy from solar panels into useable electricity for the grid. Transistors act as fast switches and control the electrical energy that flows in an electrical circuit. Turning a transistor off opens the circuit and stops the flow of electrical current; turning it on closes the circuit and allows electrical current to flow. In this way a transistor can be used to convert DC from a solar panel into AC for use in a home. Transphorm’s transistors will enable a single semiconductor device to switch electrical currents at high-voltage in both directions—making the inverter more compact and reliable. Transphorm is using Gallium Nitride (GaN) as a semiconductor material in its transistors instead of silicon, which is used in most conventional transistors, because GaN transistors have lower losses at higher voltages and switching frequencies.

  17. Method of growing GaN films with a low density of structural defects using an interlayer

    DOE Patents [OSTI]

    Bourret-Courchesne, Edith D.

    2003-01-01

    A dramatic reduction of the dislocation density in GaN was obtained by insertion of a single thin interlayer grown at an intermediate temperature (IT-IL) after the growth of an initial grown at high temperature. A description of the growth process is presented with characterization results aimed at understanding the mechanisms of reduction in dislocation density. A large percentage of the threading dislocations present in the first GaN epilayer are found to bend near the interlayer and do not propagate into the top layer which grows at higher temperature in a lateral growth mode. TEM studies show that the mechanisms of dislocation reduction are similar to those described for the epitaxial lateral overgrowth process, however a notable difference is the absence of coalescence boundaries.

  18. Performance and breakdown characteristics of irradiated vertical power GaN P-i-N diodes

    SciTech Connect (OSTI)

    King, M. P.; Armstrong, A. M.; Dickerson, J. R.; Vizkelethy, G.; Fleming, R. M.; Campbell, J.; Wampler, W. R.; Kizilyalli, I. C.; Bour, D. P.; Aktas, O.; Nie, H.; Disney, D.; Wierer, Jr., J.; Allerman, A. A.; Moseley, M. W.; Kaplar, R. J.

    2015-10-29

    Electrical performance and defect characterization of vertical GaN P-i-N diodes before and after irradiation with 2.5 MeV protons and neutrons is investigated. Devices exhibit increase in specific on-resistance following irradiation with protons and neutrons, indicating displacement damage introduces defects into the p-GaN and n- drift regions of the device that impact on-state device performance. The breakdown voltage of these devices, initially above 1700 V, is observed to decrease only slightly for particle fluence <; 1013 cm-2. Furthermore, the unipolar figure of merit for power devices indicates that while the on-resistance and breakdown voltage degrade with irradiation, vertical GaN P-i-Ns remain superior to the performance of the best available, unirradiated silicon devices and on-par with unirradiated modern SiC-based power devices.

  19. ARM - Facility News Article

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

    February 28, 2010 [Facility News] Footprint Adjustments Underway at Southern Great Plains Site Bookmark and Share Upon completion of the SGP footprint reduction, extended facilities 9, 11, 12, 15 and 21 will remain intact, along with the Central Facility (C1) near Lamont. Instrumentation at the remaining sites will be consolidated into the new, smaller footprint. Facilities closed thus far are colored black. Upon completion of the SGP footprint reduction, extended facilities 9, 11, 12, 15 and 21

  20. ARM - Facility News Article

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

    August 15, 2008 [Facility News] New Ceilometer Evaluated at Southern Great Plains Site Bookmark and Share Dan Nelson, SGP facilities manager, inspects the new ceilometer during its evaluation period on the platform of the SGP Guest Instrument Facility between June and July 2008. Dan Nelson, SGP facilities manager, inspects the new ceilometer during its evaluation period on the platform of the SGP Guest Instrument Facility between June and July 2008. To analyze cloud properties, ARM scientists

  1. ARM - Facility News Article

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

    8, 2011 [Facility News, Publications] Journal Special Issue Includes Mobile Facility Data from Germany Bookmark and Share The ARM Mobile Facility operated in Heselbach, Germany, as part of the COPS surface network. The ARM Mobile Facility operated in Heselbach, Germany, as part of the COPS surface network. In 2007, the ARM Mobile Facility participated in one of the most ambitious field studies ever conducted in Europe-the Convective and Orographically Induced Precipitation Study (COPS). Now, 21

  2. ARM - Facility News Article

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

    22, 2011 [Facility News] Request for Proposals Now Open Bookmark and Share The ARM Climate Research Facility is now accepting applications for use of an ARM mobile facility (AMF), the ARM aerial facility (AAF), and fixed sites. Proposals are welcome from all members of the scientific community for conducting field campaigns and scientific research using the ARM Facility, with availability as follows: AMF2 available December 2013 AMF1 available March 2015 AAF available between June and October

  3. ARM - Facility News Article

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

    May 15, 2008 [Facility News] National User Facility Organization Meets to Discuss Progress and Ideas Bookmark and Share In late April, the ARM Technical Director attended an annual meeting of the National User Facility Organization. Comprised of representatives from Department of Energy (DOE) national user facilities, the purpose of this group is to promote and encourage discussions among user facility administrators, their management, and their user organization representatives by communicating

  4. ARM - Facility News Article

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

    10, 2016 [Facility News] Opportunity for Cloud Properties Retrieval Algorithm Development: Request for Interest Opened Bookmark and Share The ARM Facility is seeking a scientific consultant to develop an operational cloud property algorithm, using data from ARM facilities and instruments like these scanning cloud radars. The ARM Facility is seeking a scientific consultant to develop an operational cloud property algorithm, using data from ARM facilities and instruments like these scanning cloud

  5. Facilities | Argonne National Laboratory

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

    Facilities Argonne maintains two state-of-the-art facilities for high-energy physics research. The Argonne Wakefield Accelerator Facility is home to technology that produces high accelerating gradients that could form the basis of the next generation of particle accelerators. Additionally, the 4 Tesla Magnet Facility reuses hospital MRI magnets to provide benchmarking for new muon experiments that will be performed at Fermilab. 4 Tesla Magnet Facility Learn More » Argonne Wakefield Accelerator

  6. Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

    SciTech Connect (OSTI)

    Bolat, Sami Tekcan, Burak; Ozgit-Akgun, Cagla; Biyikli, Necmi; Okyay, Ali Kemal

    2015-01-15

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metalsemiconductormetal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N{sub 2}/H{sub 2} PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH{sub 3} PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N{sub 2}:H{sub 2} ambient.

  7. Transistors for Electric Motor Drives: High-Performance GaN HEMT Modules for Agile Power Electronics

    SciTech Connect (OSTI)

    2010-09-01

    ADEPT Project: Transphorm is developing transistors with gallium nitride (GaN) semiconductors that could be used to make cost-effective, high-performance power converters for a variety of applications, including electric motor drives which transmit power to a motor. A transistor acts like a switch, controlling the electrical energy that flows around an electrical circuit. Most transistors today use low-cost silicon semiconductors to conduct electrical energy, but silicon transistors don’t operate efficiently at high speeds and voltage levels. Transphorm is using GaN as a semiconductor material in its transistors because GaN performs better at higher voltages and frequencies, and it is more energy efficient than straight silicon. However, Transphorm is using inexpensive silicon as a base to help keep costs low. The company is also packaging its transistors with other electrical components that can operate quickly and efficiently at high power levels—increasing the overall efficiency of both the transistor and the entire motor drive.

  8. GaN nanowires with pentagon shape cross-section by ammonia-source molecular beam epitaxy

    SciTech Connect (OSTI)

    Lin, Yong; Leung, Benjamin; Li, Qiming; Figiel, Jeffrey J.; Wang, George T.

    2015-07-14

    In this study, ammonia-based molecular beam epitaxy (NH3-MBE) was used to grow catalyst-assisted GaN nanowires on (11¯02) r-plane sapphire substrates. Dislocation free [112¯0] oriented nanowires are formed with pentagon shape cross-section, instead of the usual triangular shape facet configuration. Specifically, the cross-section is the result of the additional two nonpolar {101¯0} side facets, which appear due to a decrease in relative growth rate of the {101¯0} facets to the {101¯1} and {101¯1} facets under the growth regime in NH3-MBE. Compared to GaN nanowires grown by Ni-catalyzed metal–organic chemical vapor deposition, the NH3-MBE grown GaN nanowires show more than an order of magnitude increase in band-edge to yellow luminescence intensity ratio, as measured by cathodoluminescence, indicating improved microstructural and optical properties.

  9. Elimination of surface band bending on N-polar InN with thin GaN capping

    SciTech Connect (OSTI)

    Kuzmík, J. Haščík, Š.; Kučera, M.; Kúdela, R.; Dobročka, E.; Adikimenakis, A.; Mičušík, M.; Gregor, M.; Plecenik, A.; Georgakilas, A.

    2015-11-09

    0.5–1 μm thick InN (0001) films grown by molecular-beam epitaxy with N- or In-polarity are investigated for the presence of native oxide, surface energy band bending, and effects introduced by 2 to 4 monolayers of GaN capping. Ex situ angle-resolved x-ray photo-electron spectroscopy is used to construct near-surface (GaN)/InN energy profiles, which is combined with deconvolution of In3d signal to trace the presence of InN native oxide for different types of polarity and capping. Downwards surface energy band bending was observed on bare samples with native oxide, regardless of the polarity. It was found that the In-polar InN surface is most readily oxidized, however, with only slightly less band bending if compared with the N-polar sample. On the other hand, InN surface oxidation was effectively mitigated by GaN capping. Still, as confirmed by ultra-violet photo-electron spectroscopy and by energy band diagram calculations, thin GaN cap layer may provide negative piezoelectric polarization charge at the GaN/InN hetero-interface of the N-polar sample, in addition to the passivation effect. These effects raised the band diagram up by about 0.65 eV, reaching a flat-band profile.

  10. GaN nanowires with pentagon shape cross-section by ammonia-source molecular beam epitaxy

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

    Lin, Yong; Leung, Benjamin; Li, Qiming; Figiel, Jeffrey J.; Wang, George T.

    2015-07-14

    In this study, ammonia-based molecular beam epitaxy (NH3-MBE) was used to grow catalyst-assisted GaN nanowires on (11¯02) r-plane sapphire substrates. Dislocation free [112¯0] oriented nanowires are formed with pentagon shape cross-section, instead of the usual triangular shape facet configuration. Specifically, the cross-section is the result of the additional two nonpolar {101¯0} side facets, which appear due to a decrease in relative growth rate of the {101¯0} facets to the {101¯1} and {101¯1} facets under the growth regime in NH3-MBE. Compared to GaN nanowires grown by Ni-catalyzed metal–organic chemical vapor deposition, the NH3-MBE grown GaN nanowires show more than an ordermore » of magnitude increase in band-edge to yellow luminescence intensity ratio, as measured by cathodoluminescence, indicating improved microstructural and optical properties.« less

  11. Calibration Facilities | Department of Energy

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

    Calibration Facilities Calibration Facilities Calibration Facilities Calibration Facilities Calibration Facilities Calibration Facilities DOE supports the development, standardization, and maintenance of calibration facilities for environmental radiation sensors. Radiation standards at the facilities are primarily used to calibrate portable surface gamma-ray survey meters and borehole logging instruments used for uranium and other mineral exploration and remedial action measurements. Standards

  12. CRAD, Facility Safety- Nuclear Facility Design

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) that can be used for assessment of a contractor's Nuclear Facility Design.

  13. CRAD, Facility Safety- Nuclear Facility Safety Basis

    Office of Energy Efficiency and Renewable Energy (EERE)

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) that can be used for assessment of a contractor's Nuclear Facility Safety Basis.

  14. ORPS Facility Registration Form

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

    ORPS FACILITY REGISTRATION FORM Submit completed form to: U.S. Department of Energy AU User Support EMAIL: ORPSsupport@hq.doe.gov PHONE: 800-473-4375 FAX: 301-903-9823 Note:  Only one facility per form  Type or print all entries 1. TYPE OF CHANGE  Add a Facility (Complete Section 1.A, then go to Section 2)  Change a Facility (Complete Section 1.B, then go to Section)  Delete a Facility (Complete Section 1.C, then go to Section 2) A. Add a New Facility Use this section if you are

  15. Characterization of GaN nanowires grown on PSi, PZnO and PGaN on Si (111) substrates by thermal evaporation

    SciTech Connect (OSTI)

    Shekari, Leila; Hassan, Haslan Abu; Thahab, Sabah M.; Hassan, Zainuriah

    2012-06-20

    In this research, we used an easy and inexpensive method to synthesize highly crystalline GaN nanowires (NWs); on different substrates such as porous silicon (PSi), porous zinc oxide (PZnO) and porous gallium nitride (PGaN) on Si (111) wafer by thermal evaporation using commercial GaN powder without any catalyst. Micro structural studies by scanning electron microscopy and transmission electron microscope measurements reveal the role of different substrates in the morphology, nucleation and alignment of the GaN nanowires. The degree of alignment of the synthesized nanowires does not depend on the lattice mismatch between wires and their substrates. Further structural and optical characterizations were performed using high resolution X-ray diffraction and energy-dispersive X-ray spectroscopy. Results indicate that the nanowires are of single-crystal hexagonal GaN. The quality and density of grown GaN nanowires for different substrates are highly dependent on the lattice mismatch between the nanowires and their substrates and also on the size of the porosity of the substrates. Nanowires grown on PGaN have the best quality and highest density as compared to nanowires on other substrates. By using three kinds of porous substrates, we are able to study the increase in the alignment and density of the nanowires.

  16. Carrier and photon dynamics in a topological insulator Bi{sub 2}Te{sub 3}/GaN type II staggered heterostructure

    SciTech Connect (OSTI)

    Chaturvedi, P.; Chouksey, S.; Banerjee, D.; Ganguly, S.; Saha, D.

    2015-11-09

    We have demonstrated a type-II band-aligned heterostructure between pulsed laser deposited topological insulator bismuth telluride and metal organic-chemical-vapour deposited GaN on a sapphire substrate. The heterostructure shows a large valence band-offset of 3.27 eV as determined from x-ray photoelectron spectroscopy, which is close to the bandgap of GaN (3.4 eV). Further investigation using x-ray diffraction, Raman spectroscopy, and energy-dispersive x-ray spectrum reveals the stoichiometric and material properties of bismuth telluride on GaN. Steady state photon emission from GaN is found to be modulated by the charge transfer process due to diffusion across the junction. The time constant involved with the charge transfer process is found to be 0.6 ns by transient absorption spectroscopy. The heterostructure can be used for designing devices with different functionalities and improving the performance of the existing devices on GaN.

  17. ARM Climate Research Facility

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

    9 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman April ... DOESC-ARM-14-009 ARM Climate Research Facility Quarterly Value-Added Product Report First ...

  18. ARM Climate Research Facility

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

    2 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman January ... DOESC-ARM-14-002 ARM Climate Research Facility Quarterly Value-Added Product Report First ...

  19. ARM Climate Research Facility

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

    7 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman October ... DOESC-ARM-14-027 ARM Climate Research Facility Quarterly Value-Added Product Report ...

  20. ARM Climate Research Facility

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

    3 ARM Climate Research Facility Quarterly Value-Added Product Report Chitra Sivaraman ... DOESC-ARM-11-023 ARM Climate Research Facility Quarterly Value-Added Product Report ...

  1. ARM Climate Research Facility

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

    3 ARM Climate Research Facility Quarterly Ingest Status Report A Koontz C Sivaraman July ... DOESC-ARM-14-023 ARM Climate Research Facility Quarterly Ingest Report Third Quarter: ...

  2. ARM Climate Research Facility

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

    8 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman July 2015 ... DOESC-ARM-15-038 ARM Climate Research Facility Quarterly Value-Added Product Report Third ...

  3. ARM Climate Research Facility

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

    2 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman January ... DOESC-ARM-15-002 ARM Climate Research Facility Quarterly Value-Added Product Report First ...

  4. ARM Climate Research Facility

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

    0 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman July 2014 ... DOESC-ARM-14-020 ARM Climate Research Facility Quarterly Value-Added Product Report Third ...

  5. ARM Climate Research Facility

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

    2 ARM Climate Research Facility Quarterly Value-Added Product Report C Sivaraman February ... DOESC-ARM-12-002 ARM Climate Research Facility Quarterly Value-Added Product Report First ...

  6. ARM Climate Research Facility

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

    1 ARM Climate Research Facility Quarterly Value-Added Product Report Chitra Sivaraman ... DOESC-ARM-11-021 ARM Climate Research Facility Quarterly Value-Added Product Report Third ...

  7. Technology Transitions Facilities Database

    Broader source: Energy.gov [DOE]

    The types of R&D facilities at the DOE Laboratories available to the public typically fall into three broad classes depending on the mode of access: Designated User Facilities, Shared R&D...

  8. ARM - Facility News Article

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

    Data Available from ARM Mobile Facility Deployment in China Bookmark and Share The Study of Aerosol Indirect Effects in China was anchored by the ARM Mobile Facility in Shouxian ...

  9. WIPP - Public Reading Facilities

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

    Public Reading Facilities/Electronic Reading Facilities The Freedom of Information Act (FOIA) and Electronic FOIA (E-FOIA) require that various specific types of records, as well as various other records, be maintained in public reading facilities. Before you submit a FOIA request, we recommend you contact or visit the appropriate public reading facility to determine if the records you are seeking have already been released. The U.S. Department of Energy (DOE), as well as other related DOE

  10. ARM - Facility News Article

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

    January 11, 2011 [Facility News] ARM Mobile Facility Completes Extended Campaign in the Azores; Next Stop-India Bookmark and Share The ARM Mobile Facility obtained data on Graciosa Island in the Azores from May 2009 through December 2010--its longest deployment to date. The ARM Mobile Facility obtained data on Graciosa Island in the Azores from May 2009 through December 2010--its longest deployment to date. December 31, 2010, marked the last official day of data collection for the Clouds,

  11. ARM - Facility News Article

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

    Science Board Established for ARM Climate Research Facility Bookmark and Share The scientific infrastructure established by the ARM Program - heavily instrumented research sites, the ARM Data Archive, and the ARM Mobile Facility under development - is now available for use by scientists worldwide through the ARM Climate Research Facility. As a national user facility, this unique asset provides the opportunity for a broader national and international research community to study global change. The

  12. ARM - Facility News Article

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

    New Backup Software Improves Processing, Reliability at Data Management Facility Bookmark and Share Real-time data from all three of the ARM Climate Research Facility sites (North Slope of Alaska, Southern Great Plains, and Tropical Western Pacific) are collected and processed at the ARM Climate Research Facility Data Management Facility (DMF) each day. Processing involves the application of algorithms for performing simple averaging routines, qualitative comparisons, or more complicated

  13. ARM - Facility News Article

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

    March 20, 2014 [Facility News, Publications] 2013 ARM Annual Report Now Available Bookmark and Share The 2013 edition of the ARM Climate Research Facility Annual Report was published in February 2014. The first 25 pages include a short overview of the Facility, followed by featured field campaigns, user research results, and summaries of infrastructure achievements. The back portion of the report includes a summary of all 2013 field campaigns conducted throughout the ARM Facility and a

  14. ARM - Facility News Article

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

    , 2009 [Facility News] Mobile Facility Begins Marine Cloud Study in the Azores Bookmark and Share Located next to the airport on Graciosa Island, the ARM Mobile Facility's comprehensive and sophisticated instrument suite will obtain atmospheric measurements from the marine boundary layer. Located next to the airport on Graciosa Island, the ARM Mobile Facility's comprehensive and sophisticated instrument suite will obtain atmospheric measurements from the marine boundary layer. Extended

  15. ARM - Facility News Article

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

    March 22, 2007 [Facility News] GEWEX News Features Dust Data from ARM Mobile Facility Deployment Bookmark and Share Data from the recent deployment of the ARM Mobile Facility are featured in the February issue of GEWEX News. The February 2007 issue (Vol. 17, No. 1) of GEWEX News features early results from special observing periods of the African Monsoon Mutidisciplinary Analysis, including data obtained by the ARM Mobile Facility (AMF). The AMF was stationed in the central Sahel from January

  16. ARM - Facility News Article

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

    June 1, 2015 [Facility News] BAMS Features Results of 21-Month ARM Deployment Bookmark and Share Low clouds were observed typically at the Graciosa site during the 21-month ARM Mobile Facility deployment. Low clouds were observed typically at the Graciosa site during the 21-month ARM Mobile Facility deployment. Featured in the March 2015 Bulletin of the American Meteorological Society (BAMS), the 21-month ARM mobile facility deployment in the Azores was the longest of its type in a non-tropical

  17. ARM - Facility News Article

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

    8, 2015 [Facility News] New Science Board Members Tackle ARM's Expanding Landscape Bookmark and Share With facilities around the world hosting field campaigns on a regular basis, the ARM Climate Research Facility continues to be an important resource to the scientific community. Thanks to the vigilance of the ARM Science Board, the ARM Facility is able to support quality science with over 70 campaigns a year. Comprised of highly-respected scientists from the external climate research community,

  18. Sandia National Laboratories: Facilities

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

    Facilities State-Of-The-Art Supporting all elements of IMS projects Facilities Labs and Test Sites Integrated Military Systems maintains a number of state-of-the-art testing and fabrication facilities. Supporting all elements of IMS projects including design, prototyping, fabrication, development, testing, and assessments, these facilities enable customers to quickly realize their projects and get the information they need in a fast and effective way. Use the "left" and

  19. Expertise & Facilities

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

    Expertise & Facilities Expertise & Facilities Our full spectrum of end-to-end integrated capabilities in explosives make Los Alamos the ideal place to develop, characterize, and test all types of explosives and explosives threat scenarios. v Award-winning scientists, state-of-the-art facilities LACED is built upon Los Alamos' unparalleled explosives detection capabilities derived from the expertise of award-winning scientists and state-of-the-art facilities. LACED is made up of 57

  20. ARM - Facility News Article

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

    January 21, 2014 [Facility News] ARM Facility Embarks on Expansion in the United States Bookmark and Share A reconfiguration plan is being set in motion for the ARM Facility that will result in even better observations of atmospheric processes at the SGP site. A reconfiguration plan is being set in motion for the ARM Facility that will result in even better observations of atmospheric processes at the SGP site. Through 20 years of measurements at its observations sites around the world, the ARM

  1. ARM - Facility News Article

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

    July 18, 2016 [Facility News] Next Round of Deadlines for Small Campaigns Coming Up Bookmark and Share The next deadline to propose for smaller field campaigns will be August 22. Small campaigns do not require a full deployment of ARM Facility equipment, like an ARM mobile or aerial facility. They require just an instrument or two, or are in conjunction with a larger facility operation. Costing less than $25,000, these campaigns give researchers access to ARM's equipment to perform focused,

  2. NEAC Facilities Subcommittee Report

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

    Facilities Subcommittee Report Presentation to the NEAC Committee 12/11/2015 John I. Sackett Facilities Subcommittee Members * John Ahearne * Dana Christensen * Tom Cochran * Mike Corradini * Dave Hill * Hussein Khalil * Andy Klein * Paul Murray * John Sackett, chair Subcommittee Objectives * The objective of our deliberations has been to help DOE-NE develop a means to identify, prioritize and make available those facilities important to Nuclear Energy Research and Development. - All facilities

  3. ORAU South Campus Facility

    Broader source: Energy.gov [DOE]

    This document explains the cleanup activities and any use limitations for the land surrounding the ORAU South Campus Facility.

  4. Facilities Management | Jefferson Lab

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

    Facilities Management Facilities Management & Logistics is responsible for performing or specifying performance of all Jefferson Lab facility maintenance, construction, security, property, and facility services. The lab's 206-acre campus includes 169 acres owned by the U.S. Department of Energy and 37 acres owned by the Southeast Universities Research Association. In addition, the Commonwealth of Virginia owns an 8-acre parcel referred to as the Virginia Associated Research Campus (VARC)

  5. Jupiter Laser Facility

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

    jupiter laser facility Jupiter Laser Facility The commissioning of the Titan Petawatt-Class laser to LLNL's Jupiter Laser Facility (JLF) has provided a unique platform for the use of petawatt (PW)-class lasers to explore laser-matter interactions under extreme conditions. The JLF includes the Janus, Callisto, Europa, Titan, and COMET lasers and associated target chambers (see Laser Facilities). Commissioned in 2007, Titan was the first to offer synchronized operation of both a short-pulse PW

  6. TEM studies of laterally overgrown GaN layers grown on non-polarsubstrates

    SciTech Connect (OSTI)

    Liliental-Weber, Z.; Ni, X.; Morkoc, H.

    2006-01-05

    Transmission electron microscopy (TEM) was used to study pendeo-epitaxial GaN layers grown on polar and non-polar 4H SiC substrates. The structural quality of the overgrown layers was evaluated using a number of TEM methods. Growth of pendeo-epitaxial layers on polar substrates leads to better structural quality of the overgrown areas, however edge-on dislocations are found at the meeting fronts of two wings. Some misorientation between the 'seed' area and wing area was detected by Convergent Beam Electron Diffraction. Growth of pendeo-epitaxial layers on non-polar substrates is more difficult. Two wings on the opposite site of the seed area grow in two different polar directions with different growth rates. Most dislocations in a wing grown with Ga polarity are 10 times wider than wings grown with N-polarity making coalescence of these layers difficult. Most dislocations in a wing grown with Ga polarity bend in a direction parallel to the substrate, but some of them also propagate to the sample surface. Stacking faults formed on the c-plane and prismatic plane occasionally were found. Some misorientation between the wings and seed was detected using Large Angle Convergent Beam Diffraction.

  7. Radiation-induced defects in GaN bulk grown by halide vapor phase epitaxy

    SciTech Connect (OSTI)

    Duc, Tran Thien; Pozina, Galia; Son, Nguyen Tien; Janzn, Erik; Hemmingsson, Carl; Ohshima, Takeshi

    2014-09-08

    Defects induced by electron irradiation in thick free-standing GaN layers grown by halide vapor phase epitaxy were studied by deep level transient spectroscopy. In as-grown materials, six electron traps, labeled D2 (E{sub C}0.24?eV), D3 (E{sub C}0.60?eV), D4 (E{sub C}0.69?eV), D5 (E{sub C}0.96?eV), D7 (E{sub C}1.19?eV), and D8, were observed. After 2?MeV electron irradiation at a fluence of 1??10{sup 14?}cm{sup ?2}, three deep electron traps, labeled D1 (E{sub C}0.12?eV), D5I (E{sub C}0.89?eV), and D6 (E{sub C}1.14?eV), were detected. The trap D1 has previously been reported and considered as being related to the nitrogen vacancy. From the annealing behavior and a high introduction rate, the D5I and D6 centers are suggested to be related to primary intrinsic defects.

  8. Electrochemical removal of hydrogen atoms in Mg-doped GaN epitaxial layers

    SciTech Connect (OSTI)

    Lee, June Key E-mail: hskim7@jbnu.ac.kr; Hyeon, Gil Yong; Tawfik, Wael Z.; Choi, Hee Seok; Ryu, Sang-Wan; Jeong, Tak; Jung, Eunjin; Kim, Hyunsoo E-mail: hskim7@jbnu.ac.kr

    2015-05-14

    Hydrogen atoms inside of an Mg-doped GaN epitaxial layer were effectively removed by the electrochemical potentiostatic activation (EPA) method. The role of hydrogen was investigated in terms of the device performance of light-emitting diodes (LEDs). The effect of the main process parameters for EPA such as solution type, voltage, and time was studied and optimized for application to LED fabrication. In optimized conditions, the light output of 385-nm LEDs was improved by about 26% at 30 mA, which was caused by the reduction of the hydrogen concentration by ∼35%. Further removal of hydrogen seems to be involved in the breaking of Ga-H bonds that passivate the nitrogen vacancies. An EPA process with high voltage breaks not only Mg-H bonds that generate hole carriers but also Ga-H bonds that generate electron carriers, thus causing compensation that impedes the practical increase of hole concentration, regardless of the drastic removal of hydrogen atoms. A decrease in hydrogen concentration affects the current-voltage characteristics, reducing the reverse current by about one order and altering the forward current behavior in the low voltage region.

  9. Enhanced stability of Eu in GaN nanoparticles: Effects of Si co-doping

    SciTech Connect (OSTI)

    Kaur, Prabhsharan; Sekhon, S. S.; Zavada, J. M.; Kumar, Vijay

    2015-06-14

    Ab initio calculations on Eu doped (GaN){sub n} (n = 12, 13, and 32) nanoparticles show that Eu doping in nanoparticles is favorable compared with bulk GaN as a large fraction of atoms lie on the surface where strain can be released compared with bulk where often Eu doping is associated with a N vacancy. Co-doping of Si further facilitates Eu doping as strain from an oversized Eu atom and an undersized Si atom is compensated. These results along with low symmetry sites in nanoparticles make them attractive for developing strongly luminescent nanomaterials. The atomic and electronic structures are discussed using generalized gradient approximation (GGA) for the exchange-correlation energy as well as GGA + U formalism. In all cases of Eu (Eu + Si) doping, the magnetic moments are localized on the Eu site with a large value of 6μ{sub B} (7μ{sub B}). Our results suggest that co-doping can be a very useful way to achieve rare-earth doping in different hosts for optoelectronic materials.

  10. Performance enhancement of GaN metalsemiconductormetal ultraviolet photodetectors by insertion of ultrathin interfacial HfO{sub 2} layer

    SciTech Connect (OSTI)

    Kumar, Manoj E-mail: aokyay@ee.bilkent.edu.tr; Tekcan, Burak; Okyay, Ali Kemal E-mail: aokyay@ee.bilkent.edu.tr

    2015-03-15

    The authors demonstrate improved device performance of GaN metalsemiconductormetal ultraviolet (UV) photodetectors (PDs) by ultrathin HfO{sub 2} (UT-HfO{sub 2}) layer on GaN. The UT-HfO{sub 2} interfacial layer is grown by atomic layer deposition. The dark current of the PDs with UT-HfO{sub 2} is significantly reduced by more than two orders of magnitude compared to those without HfO{sub 2} insertion. The photoresponsivity at 360?nm is as high as 1.42 A/W biased at 5 V. An excellent improvement in the performance of the devices is ascribed to allowed electron injection through UT-HfO{sub 2} on GaN interface under UV illumination, resulting in the photocurrent gain with fast response time.

  11. High-power blue laser diodes with indium tin oxide cladding on semipolar (202{sup }1{sup }) GaN substrates

    SciTech Connect (OSTI)

    Pourhashemi, A. Farrell, R. M.; Cohen, D. A.; Speck, J. S.; DenBaars, S. P.; Nakamura, S.

    2015-03-16

    We demonstrate a high power blue laser diode (LD) using indium tin oxide as a cladding layer on semipolar oriented GaN. These devices show peak output powers and external quantum efficiencies comparable to state-of-the-art commercial c-plane devices. Ridge waveguide LDs were fabricated on (202{sup }1{sup }) oriented GaN substrates using InGaN waveguiding layers and GaN cladding layers. At a lasing wavelength of 451?nm at room temperature, an output power of 2.52?W and an external quantum efficiency of 39% were measured from a single facet under a pulsed injection current of 2.34?A. The measured differential quantum efficiency was 50%.

  12. National Solar Thermal Test Facility

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

    National Solar Thermal Test Facility HomeNational Solar Thermal Test Facility Permalink Pratt Whitney Rocketdyne Testing Concentrating Solar Power, EC, Energy, Facilities, ...

  13. ARM - Facility News

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

    News Media Contact Hanna Goss hanna-dot-goss-at-pnnl-dot-gov @armnewsteam Field Notes Blog Topics Field Notes117 AGU 3 AMIE 10 ARM Aerial Facility 2 ARM Mobile Facility 1 7 ARM Mobile Facility 2 47 ARM Mobile Facility 3 1 BAECC 1 BBOP 4 CARES 1 Data Quality Office 2 ENA 2 GOAMAZON 7 HI-SCALE 4 LASIC 3 MAGIC 15 MC3E 17 PECAN 3 SGP 8 STORMVEX 29 TCAP 3 Search News Search Blog News Center All Categories What's this? Social Media Guidance News Center All Categories Features and Releases Facility

  14. ARM - Facility News Archive

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

    Archive Media Contact Hanna Goss hanna-dot-goss-at-pnnl-dot-gov @armnewsteam Field Notes Blog Topics Field Notes117 AGU 3 AMIE 10 ARM Aerial Facility 2 ARM Mobile Facility 1 7 ARM Mobile Facility 2 47 ARM Mobile Facility 3 1 BAECC 1 BBOP 4 CARES 1 Data Quality Office 2 ENA 2 GOAMAZON 7 HI-SCALE 4 LASIC 3 MAGIC 15 MC3E 17 PECAN 3 SGP 8 STORMVEX 29 TCAP 3 Search News Search Blog News Center All Categories What's this? Social Media Guidance News Center All Categories Features and Releases Facility

  15. Wheelabrator Westchester Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    Westchester Biomass Facility Jump to: navigation, search Name Wheelabrator Westchester Biomass Facility Facility Wheelabrator Westchester Sector Biomass Facility Type Municipal...

  16. Hydrodynamic Testing Facilities Database | Open Energy Information

    Open Energy Info (EERE)

    Hydrodynamic Testing Facilities Database (Redirected from Hydrodynamic Testing Facilities) Jump to: navigation, search Facility Operators By viewing Hydrodynamic Testing Facilities...

  17. Oak Ridge Manufacturing Demonstration Facility (MDF) | Department...

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

    Facilities Oak Ridge Manufacturing Demonstration Facility (MDF) Oak Ridge Manufacturing Demonstration Facility (MDF) The Manufacturing Demonstration Facility (MDF) is a ...

  18. Better Catalysts through Microscopy: Nanometer Scale M1/M2 Intergrown Heterostructure in Mo-V-M Complex Oxides

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

    He, Qian; Woo, Jungwon; Belianinov, Alex; Guliants, Vadim V.; Borisevich, Albina Y

    2015-01-01

    In recent decades, catalysis research has transformed from the predominantly empirical field to one where it is possible to control the catalytic properties via characterization and modification of the atomic-scale active centers. Many phenomena in catalysis, such as synergistic effect, however, transcend the atomic scale and also require the knowledge and control of the mesoscale structure of the specimen to harness. In this paper, we use our discovery of atomic-scale epitaxial interfaces in molybdenum vanadium based complex oxide catalysts systems (i.e., MoVMO, M = Ta, Te, Sb, Nb, etc.) to achieve control of the mesoscale structure of this complex mixturemore » of very different active phases. We can now achieve true epitaxial intergrowth between the catalytically critical M1 and M2 phases in the system that are hypothesized to have synergistic interactions, and demonstrate that the resulting catalyst has improved selectivity in the initial studies. Finally, we highlight the crucial role atomic scale characterization and mesoscale structure control play in uncovering the complex underpinnings of the synergistic effect in catalysis.« less

  19. Better Catalysts through Microscopy: Nanometer Scale M1/M2 Intergrown Heterostructure in Mo-V-M Complex Oxides

    SciTech Connect (OSTI)

    He, Qian [ORNL; Woo, Jungwon [University of Cincinnati; Belianinov, Alex [ORNL; Guliants, Vadim V. [University of Cincinnati; Borisevich, Albina Y [ORNL

    2015-01-01

    In recent decades, catalysis research has transformed from the predominantly empirical field to one where it is possible to control the catalytic properties via characterization and modification of the atomic-scale active centers. Many phenomena in catalysis, such as synergistic effect, however, transcend the atomic scale and also require the knowledge and control of the mesoscale structure of the specimen to harness. In this paper, we use our discovery of atomic-scale epitaxial interfaces in molybdenum vanadium based complex oxide catalysts systems (i.e., MoVMO, M = Ta, Te, Sb, Nb, etc.) to achieve control of the mesoscale structure of this complex mixture of very different active phases. We can now achieve true epitaxial intergrowth between the catalytically critical M1 and M2 phases in the system that are hypothesized to have synergistic interactions, and demonstrate that the resulting catalyst has improved selectivity in the initial studies. Finally, we highlight the crucial role atomic scale characterization and mesoscale structure control play in uncovering the complex underpinnings of the synergistic effect in catalysis.

  20. Working with SRNL - Our Facilities- Rapid Fabrication Facility

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

    Rapid Fabrication Facility Working with SRNL Our Facilities - Rapid Fabrication Facility At SRNL's Rapid Fabrication Facility, low-cost prototypes are produced, as well as parts and complete working models

  1. Department of Energy Facilities | Department of Energy

    Energy Savers [EERE]

    Department of Energy Facilities Department of Energy Facilities Department of Energy Facilities View All Maps Addthis...

  2. Department of Energy Facilities | Department of Energy

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

    Department of Energy Facilities Department of Energy Facilities Department of Energy Facilities

  3. Highly mismatched crystalline and amorphous GaN(1-x)As(x) alloys in the whole composition range

    SciTech Connect (OSTI)

    Yu, K. M.; Novikov, S. V.; Broesler, R.; Demchenko, I. N.; Denlinger, J. D.; Liliental-Weber, Z.; Luckert, F.; Martin, R. W.; Walukiewicz, W.; Foxon, C. T.

    2009-08-29

    Alloying is a commonly accepted method to tailor properties of semiconductor materials for specific applications. Only a limited number of semiconductor alloys can be easily synthesized in the full composition range. Such alloys are, in general, formed of component elements that are well matched in terms of ionicity, atom size, and electronegativity. In contrast there is a broad class of potential semiconductor alloys formed of component materials with distinctly different properties. In most instances these mismatched alloys are immiscible under standard growth conditions. Here we report on the properties of GaN1-xAsx, a highly mismatched, immiscible alloy system that was successfully synthesized in the whole composition range using a nonequilibrium low temperature molecular beam epitaxy technique. The alloys are amorphous in the composition range of 0.17GaN to ~;;0.8 eV at x~;;0.85. The reduction in the band gap can be attributed primarily to the downward movement of the conduction band for alloys with x>0.2, and to the upward movement of the valence band for alloys with x<0.2. The unique features of the band structure offer an opportunity of using GaN1-xAsx alloys for various types of solar power conversion devices.

  4. Ultraviolet light-emitting diodes grown by plasma-assisted molecular beam epitaxy on semipolar GaN (2021) substrates

    SciTech Connect (OSTI)

    Sawicka, M.; Grzanka, S.; Skierbiszewski, C.; Turski, H.; Muziol, G.; Krysko, M.; Grzanka, E.; Sochacki, T.; Siekacz, M.; Kucharski, R.

    2013-03-18

    Multi-quantum well (MQW) structures and light emitting diodes (LEDs) were grown on semipolar (2021) and polar (0001) GaN substrates by plasma-assisted molecular beam epitaxy. The In incorporation efficiency was found to be significantly lower for the semipolar plane as compared to the polar one. The semipolar MQWs exhibit a smooth surface morphology, abrupt interfaces, and a high photoluminescence intensity. The electroluminescence of semipolar (2021) and polar (0001) LEDs fabricated in the same growth run peaks at 387 and 462 nm, respectively. Semipolar LEDs with additional (Al,Ga)N cladding layers exhibit a higher optical output power but simultaneously a higher turn-on voltage.

  5. Diagonalization of transfer matrix of supersymmetry U{sub q}(sl-caret(M+1|N+1)) chain with a boundary

    SciTech Connect (OSTI)

    Kojima, Takeo

    2013-04-15

    We study the supersymmetry U{sub q}(sl-caret(M+1|N+1)) analogue of the supersymmetric t-J model with a boundary. Our approach is based on the algebraic analysis method of solvable lattice models. We diagonalize the commuting transfer matrix by using the bosonizations of the vertex operators associated with the quantum affine supersymmetry U{sub q}(sl-caret(M+1|N+1)).

  6. Spearville Wind Energy Facility | Open Energy Information

    Open Energy Info (EERE)

    Wind Energy Facility Jump to: navigation, search Name Spearville Wind Energy Facility Facility Spearville Wind Energy Facility Sector Wind energy Facility Type Commercial Scale...

  7. Baseline Wind Energy Facility | Open Energy Information

    Open Energy Info (EERE)

    Wind Energy Facility Jump to: navigation, search Name Baseline Wind Energy Facility Facility Baseline Wind Energy Facility Sector Wind energy Facility Type Commercial Scale Wind...

  8. Ainsworth Wind Energy Facility | Open Energy Information

    Open Energy Info (EERE)

    Ainsworth Wind Energy Facility Jump to: navigation, search Name Ainsworth Wind Energy Facility Facility Ainsworth Wind Energy Facility Sector Wind energy Facility Type Commercial...

  9. Searsburg Wind Energy Facility | Open Energy Information

    Open Energy Info (EERE)

    Searsburg Wind Energy Facility Jump to: navigation, search Name Searsburg Wind Energy Facility Facility Searsburg Wind Energy Facility Sector Wind energy Facility Type Commercial...

  10. Kammerer Solar Power Facility | Open Energy Information

    Open Energy Info (EERE)

    Power Facility Facility Kammerer Solar Power Facility Sector Solar Facility Type Photovoltaics Facility Status In Service Developer Recurrent Energy Energy Purchaser Sacramento...

  11. Tribal Facilities Retrofits

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

    up resources through reduced demand" Elias Duran - Property Manager  Day to day operations of facilities  Budget control over facilities  Project needs for future space requirements  Maintenance  Capital improvements  Brief history of the Tlingit & Haida Tribes  Tour of our Juneau facilities  Historical utility cost data  Summary of Project Objectives  Expected cost and emission reductions  Strategic planning for future implementation Two separate

  12. ARM - Facility News Article

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

    7, 2009 [Facility News] Town Hall Meeting at AGU 2009 Fall Meeting Bookmark and Share ARM Climate Research Facility - New Measurement Capabilities for Climate Research Thursday, December 17, 6:15-7:15 pm, Moscone West Room 2002 American Recovery and Reinvestment Act American Recovery and Reinvestment Act Scientists from around the world use data from the ARM Climate Research Facility to study the interactions between clouds, aerosol and radiation. Through the American Recovery and Reinvestment

  13. ARM - Facility News Article

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

    January 15, 2006 [Facility News] ARM Mobile Facility Begins Year-Long Deployment in Africa Bookmark and Share Beginning on January 9, the ARM Mobile Facility began officially collecting atmospheric data from a location at the airport in Niamey, Niger, Africa. As part of the RADAGAST field campaign, the AMF will measure the effects of absorbing aerosols from desert dust in the dry season, and the effects of deep convective clouds and associated moisture loadings on the transmission of atmospheric

  14. ARM - Facility News Article

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

    November 15, 2005 [Facility News] More Server Power Improves Performance at the ARM Data Management Facility Bookmark and Share Recently, several new Sun servers joined the production system at the ARM Data Management Facility (DMF). These servers provide much needed cpu-the Central Processing Unit is the computing part of the computer known as the processor-power to handle the ever-increasing processing load. The DMF is responsible for collecting and processing hourly data from all three ARM

  15. ARM - Facility News Article

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

    20, 2010 [Facility News] ARM Mobile Facility Blogs from Steamboat Springs Bookmark and Share This month, team members for the second ARM Mobile Facility (AMF2) are in Steamboat Springs, Colorado, preparing for the Storm Peak Lab Validation Experiment, or STORMVEX. Follow their progress on the AMF2 blog, as they install instrumentation at three sites on Mount Werner. This is the first topic for the ARM News Center blog, which was developed to share a variety of ARM stories and experiences. Be

  16. ARM - Facility News Article

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

    15, 2005 [Facility News] Aging, Overworked Computer Network at SGP Gets Overhauled Bookmark and Share This aerial map of instruments deployed at the SGP Central Facility provides an indication of the computer resources needed to manage data at the site, let alone communicate with other ARM sites. Established as the first ARM research facility in 1992, the Southern Great Plains (SGP) site in Oklahoma is the "old man on the block" when it comes to infrastructure. Though significant

  17. ARM - Facility News Article

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

    30, 2005 [Facility News] Coastal Clouds Field Campaign Takes Off in July Bookmark and Share The 2-channel NFOV gets careful attention as it joins the suite of instruments collecting data for the ARM Mobile Facility field campaign at Point Reyes National Seashore. Since March 2005, the ARM Mobile Facility (AMF) has been at Point Reyes National Seashore in northern California for the Marine Stratus Radiation, Aerosol, and Drizzle Intensive Operational Period. The goals of this 6-month field

  18. ARM - Facility News Article

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

    Mobile Facility Beta Testing Complete; System Headed to California Seashore Bookmark and Share A key addition to the ARM Climate Research Facility scientific infrastructure is ready to roll...literally. In February, the ARM Mobile Facility (AMF) is being packed up and shipped from Richland, Washington, to the Point Reyes National Seashore north of San Francisco, California. There, it will be reassembled in preparation for its first deployment as part of a 6-month experiment to study the

  19. ARM - Facility News Article

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

    1, 2011 [Facility News] Data from Field Campaign in Black Forest, Germany, are Red Hot Bookmark and Share During COPS, the ARM Mobile Facility operated in Heselbach, Germany, obtaining measurements encompassing the entire life cycle of precipitation. The AMF site also hosted a number of guest instruments for supplemental field campaigns throughout the deployment. During COPS, the ARM Mobile Facility operated in Heselbach, Germany, obtaining measurements encompassing the entire life cycle of

  20. ARM - Facility News Article

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

    13, 2012 [Facility News] Another Kind of Rush in Alaska Bookmark and Share Summer time in Alaska this year brought a rush of visitors to the ARM Climate Research Facility Barrow site. North Slope of Alaska facility manager Mark Ivey hosted two prestigious groups of visitors: a Sandia National Laboratory leadership team in June and U.S. Department of Energy management from the Office of Biological and Environmental Research (BER) in August. In August, DOE management from the Office of Biological

  1. ARM - Facility News Article

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

    8, 2012 [Data Announcements, Facility News] New Data from Greenland for Arctic Climate Research Bookmark and Share Instruments for ICECAPS operate on top and inside of the Mobile Science Facility at Summit Station in Greenland. Instruments for ICECAPS operate on top and inside of the Mobile Science Facility at Summit Station in Greenland. In 2010, researchers installed a powerful suite of climate and weather instruments at Greenland's frozen research outpost, Summit Station, for a long-term

  2. ARM - Facility News Article

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

    July 10, 2007 [Facility News] Jim Mather Selected as New ARM Technical Director Bookmark and Share Congratulations to Dr. Jim Mather, who will take the position of Technical Director of the ARM Climate Research Facility effective August 1, 2007. The Technical Director is responsible and accountable for the successful overall management of the user facility and works with the other ARM managers to this end. Jim's leadership will be critical for the successful development and evolution of the

  3. ARM - Facility News Article

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

    9, 2014 [Facility News] Workshops Begin for ARM Megasites Bookmark and Share While the mission of the ARM Climate Research Facility has not changed, it is undergoing a reconfiguration to better support the linking of ARM measurements with process-oriented models. The facility reconfiguration, presented at the recent Atmospheric System Research meeting, will involve three main components: Augmenting measurements at the ARM Southern Great Plains site and the two sites on the North Slope of Alaska,

  4. ARM - Facility News Article

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

    January 15, 2008 [Facility News] ARM Mobile Facility Completes Field Campaign in Germany Bookmark and Share Researchers will study severe precipitation events that occurred in August and October 2007, stalling Rhine River traffic and causing flooding in portions of Germany. (Image source: DW-WORLD.DE) Operations at the ARM Mobile Facility (AMF) site in Heselbach, Germany, officially came to a close on January 1, 2008. As one of several measurement "supersites" situated throughout the

  5. NREL: Transportation Research - Facilities

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

    Facilities NREL conducts vehicles and fuels research in laboratories and test sites on its 327-acre main campus in Golden, Colorado, and at specialized facilities within the region. Industry, government, and university partners benefit from access to NREL equipment and facilities tailored to analyze a broad spectrum of energy-efficient vehicle and fuel technologies and innovations. NREL engineers and researchers work closely with a wide variety of partners to research and develop advanced

  6. DOE Facility Management Contracts Facility Owner Contractor

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

    Facility Management Contracts Facility Owner Contractor Award Date End Date Options/Award Term Ultimate Potential Expiration Date Contract FY Competed Parent Companies INEEL (AMWTP Ops) EM Bechtel BWXT Idaho LLC (Under Protest) 6/15/1999 3/31/2011 2 three month option periods until protest resolved 9/30/2011 M&O 1999 Bechtel National, Inc. (67%) and Babcock and Wilcox Company (33%) Portsmouth Remediation EM LATA/Parallax 1/10/2005 6/30/2010 2/28/2011 Site Clean up 2005 Los Alamos Technical

  7. Existing Facilities Rebate Program

    Broader source: Energy.gov [DOE]

    The NYSERDA Existing Facilities program merges the former Peak Load Reduction and Enhanced Commercial and Industrial Performance programs. The new program offers a broad array of different...

  8. ARM - Facility News Article

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

    Research Facility's North Slope of Alaska (NSA) locale was completed the weekend of April ... observations during arctic winters at the NSA and other high latitude research sites. ...

  9. ARM - Facility News Article

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

    ARM Climate Research Facility Lends Support to Military Flare Tests Bookmark and Share Prior to the flare tests, SGP personnel informed local landowners and fire departments about ...

  10. ARM - Facility News Article

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

    Military Facilities, Restricted Airspace Okayed to Support Arctic Cloud Experiment Bookmark and Share As shown in this aerial photo of Oliktok Point, Alaska, the USAF Long Range ...