Sample records for island ga everett

  1. ISLANDER

    Energy Science and Technology Software Center (OSTI)

    003251WKSTN00 Genomic Island Identification Software v 1.0  http://bioinformatics.sandia.gov/software 

  2. A Theological Argument for an Everett Multiverse

    E-Print Network [OSTI]

    Don N. Page

    2012-12-21T23:59:59.000Z

    Science looks for the simplest hypotheses to explain observations. Starting with the simple assumption that {\\em the actual world is the best possible world}, I sketch an {\\it Optimal Argument for the Existence of God}, that the sufferings in our universe would not be consistent with its being alone the best possible world, but the total world could be the best possible if it includes an omnipotent, omniscient, omnibenevolent God who experiences great value in creating and knowing a universe with great mathematical elegance, even though such a universe has suffering. God seems loathe to violate elegant laws of physics that He has chosen to use in His creation, such as Maxwell's equations for electromagnetism or Einstein's equations of general relativity for gravity within their classical domains of applicability, even if their violation could greatly reduce human suffering (e.g., from falls). If indeed God is similarly loathe to violate quantum unitarity (though such violations by judicious collapses of the wavefunction could greatly reduce human suffering by always choosing only favorable outcomes), the resulting unitary evolution would lead to an Everett multiverse of `many worlds', meaning many different quasiclassical histories beyond the quasiclassical history that each of us can observe over his or her lifetime. This is a theological argument for one reason why God might prefer to create a multiverse much broader than what one normally thinks of for a history of the universe.

  3. Classical Anthropic Everett model: indeterminacy in a preordained multiverse

    E-Print Network [OSTI]

    Brandon Carter

    2012-03-05T23:59:59.000Z

    Although ultimately motivated by quantum theoretical considerations, Everett's many-world idea remains valid, as an approximation, in the classical limit. However to be applicable it must in any case be applied in conjunction with an appropriate anthropic principle, whose precise formulation involves an anthropic quotient that can be normalised to unity for adult humans but that would be lower for infants and other animals. The outcome is a deterministic multiverse in which the only function of chance is the specification of one's particular identity.

  4. EVERETT L. REDMOND II Senior Director, Policy Development

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy Chinaof EnergyImpactOn July 2, 2014 in theGroup Report | DepartmentDepartmentEVERETT

  5. The End of the Many-Worlds? (or Could we save Everett's interpretation)

    E-Print Network [OSTI]

    A. Drezet

    2015-03-03T23:59:59.000Z

    This is a manuscript to be published as a book chapter. The text summarizes some of my critics concerning Everett's theory as seen from the perspective of a Bohmian. This is the second draft and comments are still welcome.

  6. A NEW ROBOT DESIGN TO PASSIVELY DAMP FLEXIBLE ROBOTIC ARMS Louis J. Everett

    E-Print Network [OSTI]

    Everett, Louis J.

    applications as well as the Department of Energy's Environmental Waste Management projects. Most of the robotsA NEW ROBOT DESIGN TO PASSIVELY DAMP FLEXIBLE ROBOTIC ARMS Louis J. Everett Mechanical and Industrial Engineering University of Texas El Paso USA Marc Compere Mechanical Engineering Department

  7. Nucleation of GaN/AlN quantum dots

    SciTech Connect (OSTI)

    Adelmann, C; Daudin, B; Oliver, R; Briggs, G; Rudd, R

    2003-10-13T23:59:59.000Z

    We study the nucleation of GaN islands grown by plasma-assisted molecular-beam epitaxy on AlN in a Stranski-Krastanov mode. In particular, we assess the variation of their height and density as a function of GaN coverage. We show that the GaN growth passes four stages: initially, the growth is layer-by-layer; subsequently, bidimensional precursor islands form, which transform into genuine three-dimensional islands. During the latter stage, the height and the density of the islands increase with GaN coverage until the density saturates. During further GaN growth, the density remains constant and a bimodal height distribution appears. The variation of island height and density as a function of substrate temperature is discussed in the framework of an equilibrium model for Stranski-Krastanov growth [R. E. Rudd et al., Phys. Rev. Lett. 90, 146101 (2003)].

  8. ambrym island vanuatu: Topics by E-print Network

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

    subpicosecond carrier dynamics C. Kadowa) Materials; accepted for publication 5 October 1999 We report the growth of self-assembled ErAs islands embedded in GaAs by molecular beam...

  9. anticosti island laurentia: Topics by E-print Network

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

    subpicosecond carrier dynamics C. Kadowa) Materials; accepted for publication 5 October 1999 We report the growth of self-assembled ErAs islands embedded in GaAs by molecular beam...

  10. aegna island tallinn: Topics by E-print Network

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

    subpicosecond carrier dynamics C. Kadowa) Materials; accepted for publication 5 October 1999 We report the growth of self-assembled ErAs islands embedded in GaAs by molecular beam...

  11. Strain dependent facet stabilization in selective-area heteroepitaxial growth of GaN nanostructures

    E-Print Network [OSTI]

    Sharma, Pradeep

    of submicron GaN islands on GaN-sapphire, AlN-sapphire, and bare sapphire substrates. It is shown that strain due to the lattice mismatch between GaN and the underlying substrate has a significant influence- structures has received less attention. Heteroepitaxial growth of GaN is commonly carried out on substrates

  12. Island Energy Snapshots

    Office of Energy Efficiency and Renewable Energy (EERE)

    These energy snapshots highlight the energy landscape of islands in the Caribbean and the surrounding area.

  13. aphae island shinan-gun: Topics by E-print Network

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

    subpicosecond carrier dynamics C. Kadowa) Materials; accepted for publication 5 October 1999 We report the growth of self-assembled ErAs islands embedded in GaAs by molecular beam...

  14. aphaedo island shinan-gun: Topics by E-print Network

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

    subpicosecond carrier dynamics C. Kadowa) Materials; accepted for publication 5 October 1999 We report the growth of self-assembled ErAs islands embedded in GaAs by molecular beam...

  15. The Biogeography of Globally Threatened Seabirds and Island Conservation Opportunities

    E-Print Network [OSTI]

    Spatz, Dena R.

    2013-01-01T23:59:59.000Z

    Phoenix Islands Huksan Do Persian Gulf Persian Gulf MaltaMaltaIslands Malta Islands Malta Islands Malta Islands Malta

  16. Arctic ice islands

    SciTech Connect (OSTI)

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01T23:59:59.000Z

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  17. Improved InGaN/GaN light-emitting diodes with a p-GaN/n-GaN/p-GaN/n-GaN/p-GaN current-

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Improved InGaN/GaN light-emitting diodes with a p-GaN/n-GaN/p-GaN/n-GaN/p-GaN current- spreading experimental and theoretical studies on the InGaN/GaN light-emitting diodes (LEDs) with optical output power and external quantum efficiency (EQE) levels substantially enhanced by incorporating p-GaN/n-GaN/p-GaN/n-GaN/p-GaN

  18. Interconnection Guidelines (Rhode Island)

    Broader source: Energy.gov [DOE]

    Rhode Island enacted legislation (HB 6222) in June 2011 to standardize the application process for the interconnection of customer-sited renewable-energy systems to the state’s distribution grid....

  19. Forestry Policies (Rhode Island)

    Broader source: Energy.gov [DOE]

    Rhode Island's forests cover over half of the state's land area, and are managed by the Department of Environmental Management, Division of Forest Environment. The State issued its "Forest...

  20. On the effect of N-GaN/P-GaN/N-GaN/P-GaN/N-GaN built-in junctions in the n-GaN layer for

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    On the effect of N-GaN/P-GaN/N-GaN/P-GaN/N- GaN built-in junctions in the n-GaN layer for InGaN/GaN: N-GaN/P-GaN/N-GaN/P-GaN/N-GaN (NPNPN-GaN) junctions embedded between the n-GaN region and multiple the performance of InGaN/GaN light emitting diodes (LEDs) in this work. In the proposed architecture, each thin P-GaN

  1. Elemental diffusion during the droplet epitaxy growth of In(Ga)As/GaAs(001) quantum dots by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Chen, Z. B.; Chen, B.; Wang, Y. B.; Liao, X. Z., E-mail: xiaozhou.liao@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Lei, W. [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009 (Australia); Tan, H. H.; Jagadish, C. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Zou, J. [Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, QLD 4072 (Australia); Ringer, S. P. [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia)

    2014-01-13T23:59:59.000Z

    Droplet epitaxy is an important method to produce epitaxial semiconductor quantum dots (QDs). Droplet epitaxy of III-V QDs comprises group III elemental droplet deposition and the droplet crystallization through the introduction of group V elements. Here, we report that, in the droplet epitaxy of InAs/GaAs(001) QDs using metal-organic chemical vapor deposition, significant elemental diffusion from the substrate to In droplets occurs, resulting in the formation of In(Ga)As crystals, before As flux is provided. The supply of As flux suppresses the further elemental diffusion from the substrate and promotes surface migration, leading to large island formation with a low island density.

  2. A new golden era in island biogeography

    E-Print Network [OSTI]

    Fernandez-Palacios, Jose Maria; Kueffer, Christoph; Drake, Donald

    2015-01-01T23:59:59.000Z

    Insular woodiness on the Canary Islands: a remarkable caseevery five days in the Canary Islands (Martín Esquivel et

  3. PSEG Long Island- Net Metering

    Broader source: Energy.gov [DOE]

    Although PSEG Long Island’s net metering policy is not governed by the State’s net metering law, the provisions are similar to the State law. Net metering is available for residential, non-reside...

  4. Long Island Solar Farm

    SciTech Connect (OSTI)

    Anders, R.

    2013-05-01T23:59:59.000Z

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  5. Step-flow growth mode instability of N-polar GaN under N-excess

    SciTech Connect (OSTI)

    Chèze, C. [TopGaN Ltd., Soko?owska 29/37, 01142 Warszawa (Poland)] [TopGaN Ltd., Soko?owska 29/37, 01142 Warszawa (Poland); Sawicka, M.; Siekacz, M.; ?ucznik, B.; Bo?kowski, M.; Skierbiszewski, C. [TopGaN Ltd., Soko?owska 29/37, 01142 Warszawa (Poland) [TopGaN Ltd., Soko?owska 29/37, 01142 Warszawa (Poland); Institute of High Pressure Physics, PAS, Soko?owska 29/37, 01142 Warszawa (Poland); Turski, H.; Cywi?ski, G.; Smalc-Koziorowska, J.; Weyher, J. L.; Kry?ko, M. [Institute of High Pressure Physics, PAS, Soko?owska 29/37, 01142 Warszawa (Poland)] [Institute of High Pressure Physics, PAS, Soko?owska 29/37, 01142 Warszawa (Poland)

    2013-08-12T23:59:59.000Z

    GaN layers were grown on N-polar GaN substrates by plasma-assisted molecular beam epitaxy under different III/V ratios. Ga-rich conditions assure step-flow growth with atomically flat surface covered by doubly-bunched steps, as for Ga-polar GaN. Growth under N-excess however leads to an unstable step-flow morphology. Particularly, for substrates slightly miscut towards <1010>, interlacing fingers are covered by atomic steps pinned on both sides by small hexagonal pits. In contrast, a three-dimensional island morphology is observed on the Ga-polar equivalent sample. We attribute this result to lower diffusion barriers on N-polar compared to Ga-polar GaN under N-rich conditions.

  6. GREEN HOMES LONG ISLAND

    E-Print Network [OSTI]

    Kammen, Daniel M.

    energy bill, reduce your carbon footprint... at little or no cost to you. #12;A Message From Supervisor energy-efficient and reduce our community's carbon footprint. Why do we call it Long Island Green Homes to yourevery day. By making basic improvements to yourevery day home, you can reduce your carbon footprint

  7. Culturing revolution : the local Communists of China's Hainan Island

    E-Print Network [OSTI]

    Murray, Jeremy Andrew

    2011-01-01T23:59:59.000Z

    One: Deserted Treasure Island……………………………………………….13 ChapterChapter One Deserted Treasure Island: The Social Ecology andIsolated Island/Treasure Island – Gudao / Baodao Social and

  8. Rhode Island Stormwater Design and Installation Standards Manual (Rhode Island)

    Broader source: Energy.gov [DOE]

    Rhode Island's stormwater design and installation standards manual has been developed to describe mandatory and suggested stormwater design and performance criteria for applicants to the Department...

  9. Nanostructured GaN Nucleation Layer for Light-Emitting Diodes

    SciTech Connect (OSTI)

    Narayan, Jagdish [North Carolina State University; Pant, Punam [North Carolina State University; Wei, Wei [North Carolina State University; Narayan, Roger [University of North Carolina, Chapel Hill; Budai, John D [ORNL

    2007-01-01T23:59:59.000Z

    This paper addresses the formation of nanostructured gallium nitride nucleation (NL) or initial layer (IL), which is necessary to obtain a smooth surface morphology and reduce defects in h-GaN layers for light-emitting diodes and lasers. From detailed X-ray and HR-TEM studies, researchers determined that this layer consists of nanostructured grains with average grain size of 25 nm, which are separated by small-angle grain boundaries (with misorientation 1 ), known as subgrain boundaries. Thus NL is considered to be single-crystal layer with mosaicity of about 1 . These nc grains are mostly faulted cubic GaN (c-GaN) and a small fraction of unfaulted c-GaN. This unfaulted Zinc-blende c-GaN, which is considered a nonequilibrium phase, often appears as embedded or occluded within the faulted c-GaN. The NL layer contained in-plane tensile strain, presumably arising from defects due to island coalescence during Volmer-Weber growth. The 10L X-ray scans showed c-GaN fraction to be over 63% and the rest h-GaN. The NL layer grows epitaxially with the (0001) sapphire substrate by domain matching epitaxy, and this epitaxial relationship is remarkably maintained when c-GaN converts into h-GaN during high-temperature growth.

  10. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2003 ­ August 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  11. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

  12. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2003 ­ May 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  13. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2003 ­ November 30, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  14. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  15. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2004 ­ August 31, 2004 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  16. Minnesota Nuclear Profile - Prairie Island

    U.S. Energy Information Administration (EIA) Indexed Site

    Prairie Island" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

  17. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2004 ­ February 28, 2005 Prepared for Massachusetts.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distribution

  18. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2004 ­ November 30, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution.............

  19. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2005 ­ May 31, 2005 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distribution

  20. Photoluminescence line width of self-assembled Ge(Si) islands arranged between strained Si layers

    SciTech Connect (OSTI)

    Shaleev, M. V., E-mail: shaleev@ipm.sci-nnov.ru; Novikov, A. V.; Baydakova, N. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Kuznetsov, O. A. [Nizhny Novgorod State University, Physico-Technical Research Institute (Russian Federation); Lobanov, D. N.; Krasilnik, Z. F. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2011-02-15T23:59:59.000Z

    The effect of variations in the strained Si layer thicknesses, measurement temperature, and optical excitation power on the width of the photoluminescence line produced by self-assembled Ge(Si) nanoislands, which are grown on relaxed SiGe/Si(001) buffer layers and arranged between strained Si layers, is studied. It is shown that the width of the photoluminescence line related to the Ge(Si) islands can be decreased or increased by varying the thickness of strained Si layers lying above and under the islands. A decrease in the width of the photoluminescence line of the Ge(Si) islands to widths comparable with the width of the photoluminescence line of quantum dot (QD) structures based on direct-gap InAs/GaAs semiconductors is attained with consideration of diffusive smearing of the strained Si layer lying above the islands.

  1. MHTGR-Nuclear Island Engineering: Final summary report for the period November 30, 1987 through December 1, 1988

    SciTech Connect (OSTI)

    NONE

    1988-12-01T23:59:59.000Z

    This report summarizes the Modular High-Temperature Gas-Cooled Reactor (MHTGR) - Nuclear Island Engineering (NIE) design and development work performed by General Atomics (GA) for the period November 30, 1987 through December 1, 1988, under the Department of Energy (DOE) Contract AC03-88SF17367. The scope of the report includes work performed by Bechtel National Inc. (BNI), Combustion Engineering Inc. (C-E), and James Howden Company, as major subcontractors to GA.

  2. Quantifying Vegetation Recovery on Santa Rosa Island

    E-Print Network [OSTI]

    Rentschlar, Elizabeth

    2014-12-09T23:59:59.000Z

    The rate of recovery on barrier islands after hurricanes is not well understood, because the majority of studies have focused on the geomorphic impact of storms on barrier islands. Dune vegetation recovery is a vital component of barrier island...

  3. Advantages of the Blue InGaN/GaN Light-Emitting Diodes with an AlGaN/GaN/AlGaN Quantum Well Structured Electron Blocking Layer

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Advantages of the Blue InGaN/GaN Light-Emitting Diodes with an AlGaN/GaN/AlGaN Quantum Well ABSTRACT: InGaN/GaN light-emitting diodes (LEDs) with p-(AlGaN/GaN/AlGaN) quantum well structured electron. The proposed QWEBL LED structure, in which a p-GaN QW layer is inserted in the p-AlGaN electron blocking layer

  4. Nauru Island Effect Study

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at 2:00 P.M. Next8,NatureNauru Island

  5. Micromechanical resonators fabricated from lattice-matched and etch-selective GaAs/InGaP/GaAs heterostructures

    E-Print Network [OSTI]

    Micromechanical resonators fabricated from lattice-matched and etch-selective GaAs/InGaP September 2007 Utilizing lattice-matched GaAs/InGaP/GaAs heterostructures, clean micromechanical resonators are fabricated and characterized. The nearly perfect selectivity of GaAs/InGaP is demonstrated by realizing

  6. Small-Scale Solar Grants (Rhode Island)

    Broader source: Energy.gov [DOE]

    The Rhode Island Economic Development Corporation (RIEDC) provides incentives for renewable-energy projects. Incentive programs are funded by the Rhode Island Renewable Energy Fund (RIREF) and...

  7. Energy Transition Initiative: Islands Playbook (Book) | OSTI...

    Office of Scientific and Technical Information (OSTI)

    Energy Transition Initiative: Islands Playbook (Book) Re-direct Destination: The Island Energy Playbook (the Playbook) provides an action-oriented guide to successfully initiating,...

  8. The Theory of Island Biogeography

    E-Print Network [OSTI]

    Landweber, Laura

    The Theory of Island Biogeography Robert H. MacArthur and Edward O. Wilson The young biologists" dominated by the collection of data. In The Theory of Island Biogeography they set out to change that by devel- oping a general mathema- tical theory that would make sense of a key ecological problem

  9. Ga nanoparticle-enhanced photoluminescence of GaAs

    SciTech Connect (OSTI)

    Kang, M.; Al-Heji, A. A.; Jeon, S.; Wu, J. H. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Lee, J.-E.; Saucer, T. W.; Zhao, L.; Sih, V. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States); Katzenstein, A. L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, Eckerd College, St. Petersburg, Florida 33711-4744 (United States); Sofferman, D. L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, Adelphi University, Garden City, New York 11530-0701 (United States); Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)

    2013-09-02T23:59:59.000Z

    We have examined the influence of surface Ga nanoparticles (NPs) on the enhancement of GaAs photoluminescence (PL) efficiency. We have utilized off-normal focused-ion-beam irradiation of GaAs surfaces to fabricate close-packed Ga NP arrays. The enhancement in PL efficiency is inversely proportional to the Ga NP diameter. The maximum PL enhancement occurs for the Ga NP diameter predicted to maximize the incident electromagnetic (EM) field enhancement. The PL enhancement is driven by the surface plasmon resonance (SPR)-induced enhancement of the incident EM field which overwhelms the SPR-induced suppression of the light emission.

  10. Nucleation of single GaN nanorods with diameters smaller than 35 nm by molecular beam epitaxy

    SciTech Connect (OSTI)

    Chen, Yen-Ting [Institute of Atomic and Molecular Sciences, Academia Sinica, 10617 Taipei, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, 10617 Taipei, Taiwan (China); Department of Physics, Chemistry and Biology (IFM), Linköping University, S-58183 Linköping (Sweden); Araki, Tsutomu [Department of Electrical and Electronic Engineering, Ritsumeikan University, 525-8577 Shiga (Japan)] [Department of Electrical and Electronic Engineering, Ritsumeikan University, 525-8577 Shiga (Japan); Palisaitis, Justinas; Persson, Per O. Å.; Olof Holtz, Per; Birch, Jens [Department of Physics, Chemistry and Biology (IFM), Linköping University, S-58183 Linköping (Sweden)] [Department of Physics, Chemistry and Biology (IFM), Linköping University, S-58183 Linköping (Sweden); Chen, Li-Chyong [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China)] [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China); Chen, Kuei-Hsien [Institute of Atomic and Molecular Sciences, Academia Sinica, 10617 Taipei, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, 10617 Taipei, Taiwan (China); Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China); Nanishi, Yasushi [Global Innovation Research Organization, Ritsumeikan University, 525-8577 Shiga (Japan)] [Global Innovation Research Organization, Ritsumeikan University, 525-8577 Shiga (Japan)

    2013-11-11T23:59:59.000Z

    Nucleation mechanism of catalyst-free GaN nanorod grown on Si(111) is investigated by the fabrication of uniform and narrow (<35 nm) nanorods without a pre-defined mask by molecular beam epitaxy. Direct evidences show that the nucleation of GaN nanorods stems from the sidewall of the underlying islands down to the Si(111) substrate, different from commonly reported ones on top of the island directly. Accordingly, the growth and density control of the nanorods is exploited by a “narrow-pass” approach that only narrow nanorod can be grown. The optimal size of surrounding non-nucleation area around single nanorod is estimated as 88 nm.

  11. Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots

    SciTech Connect (OSTI)

    Huang, S.; Kim, S. J.; Pan, X. Q. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Goldman, R. S., E-mail: rsgold@umich.edu [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-07-21T23:59:59.000Z

    We have examined the origins of interlayer formation and misfit dislocation (MD) displacement in the vicinity of InAs/GaAs quantum dots (QDs). For QDs formed by the Stranski-Krastanov mode, regularly spaced MDs nucleate at the interface between the QD and the GaAs buffer layer. In the droplet epitaxy case, both In island formation and In-induced “nano-drilling” of the GaAs buffer layer are observed during In deposition. Upon annealing under As flux, the In islands are converted to InAs QDs, with an InGaAs interlayer at the QD/buffer interface. Meanwhile, MDs nucleate at the QD/interlayer interface.

  12. AlGaN/GaN-based power semiconductor switches

    E-Print Network [OSTI]

    Lu, Bin, Ph. D. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    AlGaN/GaN-based high-electron-mobility transistors (HEMTs) have great potential for their use as high efficiency and high speed power semiconductor switches, thanks to their high breakdown electric field, mobility and ...

  13. GaAs/InGaP/AlGaAs quantum-well infrared photodetectors

    SciTech Connect (OSTI)

    Keshagupta, P.; Radpour, F. [Univ. of Cincinnati, OH (United States)

    1994-12-31T23:59:59.000Z

    In this paper, a new quantum-well infrared photodetector (QWIP) based on bound-to-miniband transitions in a GaAs/InGaP quantum well with GaAs/AlGaAs short superlattice barriers is presented and compared with the conventional GaAs/InGaP QWIPs. Results of the theoretical calculations of the detector parameters and the preliminary fabrication results of an embedded-well to miniband (EWTMB) GaAs/InGaP/AlGaAs quantum well/superlattice detector are presented. The advantages of the proposed design include improvement of the material quality, ability to adjust the peak wavelength in 8--12 {micro}m range, and in the lower dark current.

  14. Island Political Economy Geoff Bertram & Bernard Poirine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    323 Chapter 10 Island Political Economy Geoff Bertram & Bernard Poirine Introduction In this chapter we build on the observation that island economies, and especially small ones (population below one of development strategies. Common elements of "islandness" may serve to define island economies as a general

  15. Long Island Solar Farm Project Overview

    E-Print Network [OSTI]

    Ohta, Shigemi

    Long Island Solar Farm #12;Project Overview The Long Island Solar Farm (LISF) is a 32-megawatt. Project Developer/Owner/Operator: Long Island Solar Farm, LLC (BP Solar & MetLife) Purchaser of Power and construct arrays ~ 2 years of output (88,000 MWh equivalent) Long Island Solar Farm #12;Other Pollutants

  16. The State of Coral Reef Ecosystems of the Republic of the Marshall Islands MarshallIslands

    E-Print Network [OSTI]

    Queensland, University of

    The State of Coral Reef Ecosystems of the Republic of the Marshall Islands 387 MarshallIslands The State of Coral Reef Ecosystems of the Republic of the Marshall Islands Maria Beger1 , Dean Jacobson22 (1,940,000 mi2 ), the Republic of the Marshall Islands (RMI) is comprised of 1,225 islands

  17. EIS-0006: Wind Turbine Generator System, Block Island, Rhode Island

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy prepared this EIS to evaluate the environmental impacts of installing and operating a large experimental wind turbine, designated the MOD-OA, which is proposed to be installed on a knoll in Rhode Island's New Meadow Hill Swamp, integrated with the adjacent Block Island Power Company power plant and operated to supply electricity to the existing utility network.

  18. Carrier spin relaxation in GaInNAsSb/GaNAsSb/GaAs quantum well

    SciTech Connect (OSTI)

    Asami, T.; Nosho, H.; Tackeuchi, A. [Department of Applied Physics, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Li, L. H.; Harmand, J. C. [Laboratory for Photonics and Nanostructures-CNRS, Site Alcatel de Marcoussis, Route de Nozay, 91460 Marcoussis (France); Lu, S. L. [Suzhou Institute of Nano-tech and Nano-bionics, CAS, Dushu, Lake Higher Education Town, Ruoshui Road 398, Suzhou Industrial Park, Suzhou 215125 (China)

    2011-12-23T23:59:59.000Z

    We have investigated the carrier spin relaxation in GaInNAsSb/GaNAsSb/GaAs quantum well (QW) by time-resolved photoluminescence (PL) measurement. The sample consists of an 8-nm-thick GaIn{sub 0.36}N{sub 0.006}AsSb{sub 0.015} well, 5-nm-thick GaN{sub 0.01}AsSb{sub 0.11} intermediate barriers and 100-nm-thick GaAs barriers grown by molecular beam epitaxy on a GaAs(100) substrate. The spin relaxation time and recombination lifetime at 10 K are measured to be 228 ps and 151 ps, respectively. As a reference, we have also obtained a spin relaxation time of 125 ps and a recombination lifetime of 63 ps for GaInNAs/GaNAs/GaAs QW. This result shows that crystal quality is slightly improved by adding Sb, although these short carrier lifetimes mainly originate from a nonradiative recombination. These spin relaxation times are longer than the 36 ps spin relaxation time of InGaAs/InP QWs and shorter than the 2 ns spin relaxation time of GaInNAs/GaAs QW.

  19. No Company Is An Island

    E-Print Network [OSTI]

    Maddox, A.

    No company is an island. Utilities and their industrial customers are discovering that collaboration can breed opportunity while isolation can lead to ruin. Inter company relationships have changed over recent years and HL&P and its customers...

  20. Pacific Islands Region News Release

    E-Print Network [OSTI]

    Pacific Islands Region News Release Contact: Wende Goo FOR IMMEDIATE RELEASE 808-721-4098 May 27 of these unique twins by contributing more than 100 hours of work to construct a holding pen for the young seal

  1. Climate Action Plan (Rhode Island)

    Broader source: Energy.gov [DOE]

    In the fall of 2001, the Department of Environmental Management (DEM), the RI State Energy Office (SEO), and the Governor's office convened the Rhode Island Greenhouse Gas Stakeholder Project in...

  2. The Long Island Solar Farm

    Broader source: Energy.gov [DOE]

    In November 2011, a utility-scale solar array became operational in the most unlikely of places: at Brookhaven National Laboratory on densely populated Long Island, New York. Now the largest...

  3. Compositionally-graded InGaAsInGaP alloys and GaAsSb alloys for metamorphic InP on GaAs

    E-Print Network [OSTI]

    Compositionally-graded InGaAs­InGaP alloys and GaAsSb alloys for metamorphic InP on GaAs Li Yang a of tandem graded layers of InGaAs and InGaP with compositional grading of the In concentration. This tandem

  4. Site response at Treasure and Yerba Buena Islands, California

    E-Print Network [OSTI]

    Baise, L G; Glaser, Steven D; Dreger, D

    2003-01-01T23:59:59.000Z

    array at the Treasure Island Naval Station. ’’ Loma Prietadamage in Oakland, Treasure Island, and San Francisco. ’’C. H. ?1969?. ‘‘Treasure Island ?ll. ’’ Bay mud developments

  5. Low frequency noise in AlGaN/InGaN/GaN double heterostructure field effect transistors

    E-Print Network [OSTI]

    Pala, Nezih

    Torr and consisted of a 1.4 lm undoped GaN buffer layer on i-SiC substrate, * Corresponding authorLow frequency noise in AlGaN/InGaN/GaN double heterostructure field effect transistors N. Pala a November 2002 Abstract Low-frequency noise in AlGaN/InGaN/GaN double heterostructure field effect

  6. Polarization-engineered GaN/InGaN/GaN tunnel diodes

    E-Print Network [OSTI]

    Sriram Krishnamoorthy; Digbijoy N. Nath; Fatih Akyol; Pil Sung Park; Michele Esposto; Siddharth Rajan

    2010-08-24T23:59:59.000Z

    We report on the design and demonstration of polarization-engineered GaN/InGaN/GaN tunnel junction diodes with high current density and low tunneling turn-on voltage. Wentzel-Kramers-Brillouin (WKB) calculations were used to model and design tunnel junctions with narrow bandgap InGaN-based barrier layers. N-polar p-GaN/In0.33Ga0.67N/n-GaN heterostructure tunnel diodes were grown using molecular beam epitaxy. Efficient zero bias tunneling turn-on with a high current density of 118 A/cm2 at a reverse bias of 1V, reaching a maximum current density up to 9.2 kA/cm2 were obtained. These results represent the highest current density reported in III-nitride tunnel junctions, and demonstrate the potential of III-nitride tunnel devices for a broad range of optoelectronic and electronic applications.

  7. Violet to deep-ultraviolet InGaN/GaN and GaN/AlGaN quantum structures for UV electroabsorption modulators

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Violet to deep-ultraviolet InGaN/GaN and GaN/AlGaN quantum structures for UV electroabsorption In this paper, we present four GaN based polar quantum structures grown on c-plane embedded in p-i-n diode GaN/AlGaN quantum structures for operation in the deep-UV spectral region and the other three

  8. Luminescence Efficiency of InGaN/GaN Quantum Wells on Bulk GaN Substrate M. Dworzak1

    E-Print Network [OSTI]

    Nabben, Reinhard

    Luminescence Efficiency of InGaN/GaN Quantum Wells on Bulk GaN Substrate M. Dworzak1 , T. Stempel1/37, 01-142 Warsaw, Poland ABSTRACT Time-integrated and time-resolved photoluminescence measurements on InGaN quantum wells grown by MOCVD on two different substrates (sapphire and GaN) show that the lumines- cence

  9. Biofuel Feedstock Inter-Island Transportation

    E-Print Network [OSTI]

    Biofuel Feedstock Inter-Island Transportation Prepared for the U.S. Department of Energy Office ........................................................................... 11 Options for liquid biofuel feedstock transport ............................................................................. agency thereof. #12;A Comparison of Hawaii's Inter-Island Maritime Transportation of Solid Versus Liquid

  10. REAP Islanded Grid Wind Power Conference

    Broader source: Energy.gov [DOE]

    Hosted by Renewable Energy Alaska Project, this three-day conference will show attendees how to learn, network, and share information on wind systems in island and islanded grid environments through expert panel discussions, stakeholder dialogue, and training.

  11. Analysis of InGaN light-emitting diodes with GaN-AlGaN and AlGaN-GaN composition-graded barriers

    SciTech Connect (OSTI)

    Yang, Yujue; Wang, Junxi; Li, Jinmin; Zeng, Yiping, E-mail: ypzeng@semi.ac.cn [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2014-06-21T23:59:59.000Z

    The effects of InGaN-based light-emitting diodes (LEDs) with Al composition increasing and decreasing GaN-AlGaN barriers along the growth direction are studied numerically. Simulation results suggest that the LEDs with GaN-AlGaN composition-decreased barriers show more significant enhancement of light-output power and internal quantum efficiency than LEDs with composition-increasing GaN-AlGaN barriers when compared with the conventional LED with GaN barriers, due to the improvement in hole injection efficiency and electron blocking capability. Moreover, the optical performance is further improved by replacing GaN-AlGaN barriers with AlGaN-GaN barriers of the same Al composition-decreasing range, which are mainly attributed to the modified band diagrams. In addition, the major causes of the different efficiency droop behaviors for all the designed structures are explained by the electron leakage current and the different increase rates of hole concentration with injection current.

  12. Design and fabrication of InGaN/GaN heterojunction bipolar transistors for microwave power amplifiers

    E-Print Network [OSTI]

    Keogh, David Martin

    2006-01-01T23:59:59.000Z

    T. Henderson, “High- Speed InGaP/GaAs HBT’s Using a SimpleA typical AlGaAs/GaAs HBT or InGaP/GaAs HBT has the opposite

  13. Evolution Of Surface Topography On GaAs(100) And GaAs(111) At Normal And Oblique Incidence Of Ar{sup +}-Ions

    SciTech Connect (OSTI)

    Venugopal, V.; Basu, T.; Garg, S.; Majumder, S.; Sarangi, S. N.; Som, T. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Das, P.; Bhattacharyya, S. R.; Chini, T. K. [Surface Physics Division, Saha Institute of Nuclear Physics, Kolkata 700 064 (India)

    2010-10-04T23:59:59.000Z

    Nanoscale surface structures emerging from medium energy (50-60 keV)Ar{sup +}-ion sputtering of p-type GaAs(100) and semi-insulating GaAs(111) substrates have been investigated. For normally incident 50 keV Ar{sup +}-ions of fluence 1x10{sup 17} ions/cm{sup 2} on GaAs(100) and GaAs(111) features in the form of nanoscale pits/holes without short range ordering are observed with densities 5.2x10{sup 9} /cm{sup 2} and 5.9x10{sup 9} /cm{sup 2}, respectively along with irregularly shaped patches of islands. For GaAs(111) on increasing the influence to 5x10{sup 17} /cm{sup 2} the pit density increases marginally to 6.2x10{sup 9} /cm{sup 2}. For 60 deg. off-normal incidence of 60 keV Ar.{sup +}-ions of fluence 2x10{sup 17} ions/cm{sup 2} on GaAs(100) microscale wavelike surface topography is observed. In all cases well-defined nanodots are absent on the surface.

  14. Islands and Our Renewable Energy Future (Presentation)

    SciTech Connect (OSTI)

    Baring-Gould, I.; Gevorgian, V.; Kelley, K.; Conrad, M.

    2012-05-01T23:59:59.000Z

    Only US Laboratory Dedicated Solely to Energy Efficiency and Renewable Energy. High Contribution Renewables in Islanded Power Systems.

  15. Investigation of the GaN-on-GaAs interface for vertical power device applications

    SciTech Connect (OSTI)

    Möreke, Janina, E-mail: janina.moereke@bristol.ac.uk; Uren, Michael J.; Kuball, Martin [H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Novikov, Sergei V.; Foxon, C. Thomas [Department of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Hosseini Vajargah, Shahrzad; Wallis, David J.; Humphreys, Colin J. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Haigh, Sarah J. [Super STEM Laboratory, STFC Daresbury Campus, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Al-Khalidi, Abdullah; Wasige, Edward; Thayne, Iain [School of Engineering, University of Glasgow, Rankine Bldg, Oakfield Avenue, Glasgow G12 8LT (United Kingdom)

    2014-07-07T23:59:59.000Z

    GaN layers were grown onto (111) GaAs by molecular beam epitaxy. Minimal band offset between the conduction bands for GaN and GaAs materials has been suggested in the literature raising the possibility of using GaN-on-GaAs for vertical power device applications. I-V and C-V measurements of the GaN/GaAs heterostructures however yielded a rectifying junction, even when both sides of the junction were heavily doped with an n-type dopant. Transmission electron microscopy analysis further confirmed the challenge in creating a GaN/GaAs Ohmic interface by showing a large density of dislocations in the GaN layer and suggesting roughening of the GaN/GaAs interface due to etching of the GaAs by the nitrogen plasma, diffusion of nitrogen or melting of Ga into the GaAs substrate.

  16. ANNUAL FISH PASSAGE REPORT ROCK ISLAND DAM

    E-Print Network [OSTI]

    ANNUAL FISH PASSAGE REPORT ROCK ISLAND DAM COLUMBIA RIVER, WASHINGTON, 1959 :y .iiJA/i-3ri ^' WUUUi. ANNUAL FISH PASSAGE REPORT - ROCK ISLAND DAM COLUMBIA RIVER, WASHINGTON, 1959 by Paul D. Zimmer, Clifton and observations 10 Summary 13 #12;#12;ANNUAL FISH PASSAGE REPORT - ROCK ISLAND DAM COLUMBIA RIVER, WASHINGTON

  17. ANNUAL FISH PASSAGE REPORT ROCK ISLAND DAM

    E-Print Network [OSTI]

    ANNUAL FISH PASSAGE REPORT ROCK ISLAND DAM COLUMBIA RIVER, WASHINGTON 1960 . SPECIAL SCIENTIFIC ISLAND DAM COLUMBIA RIVER, WASHINGTON, 1960 by Paul D. Zimmer and Clifton C. Davidson United States Fish This annual report of fishway operations at Rock Island Dam in 1960 is dedicated to the memory of co

  18. ANNUAL FISH PASSAGE REPORT ROCK ISLAND DAM

    E-Print Network [OSTI]

    42) ANNUAL FISH PASSAGE REPORT ROCK ISLAND DAM COLUMBIA RIVER, WASHINGTON 1961 Marine Biological. McKeman, Director ANNUAL FISH PASSAGE REPORT - ROCK ISLAND DAM COLUMBIA RIVER, WASHINGTON, 1961--Fisheries No. 421 Washington, D. C. April 1962 #12;Rock Island Dam, Columbia River, Washington ii #12;CONTENTS

  19. Annual Fish Passage Report -Rock Island Dam

    E-Print Network [OSTI]

    Annual Fish Passage Report - Rock Island Dam Columbia River, Washington, 1965 By Paul D. Zimmer L. McKeman, Director Annual Fish Passage Report - Rock Island Dam Columbia River, Washington, 1965;#12;Annual Fish Passage Report - Rock Island Dam Columbia River, Washington, 1965 By PAUL D. ZIMMER, Fishery

  20. Close Encounters Treasure Island: Sequencing Moorea

    E-Print Network [OSTI]

    Wildermuth, Mary C

    Close Encounters Also... Treasure Island: Sequencing Moorea Devon Zagory on Food Safety College Features 12 CLOSE ENCOUNTERS by Claire Cain Miller Passing earth science to the next generation 20 TREASURE ISLAND by Erika Check Barcoding CNR's island research station Departments 2 L

  1. Slide 1

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

    America LNG Import Terminals Status: Existing Source: Various Public Sources Everett Cove Point Lake Charles Elba Island Gulf Gateway (*Decommissioning) Altamira Existing Terminals...

  2. Ga NMR spectra and relaxation in wurtzite GaN M. Corti and A. Gabetta

    E-Print Network [OSTI]

    Svane, Axel Torstein

    69,71 Ga NMR spectra and relaxation in wurtzite GaN M. Corti and A. Gabetta Department of Physics properties of wurtzite GaN are studied by Ga nuclear magnetic resonance NMR in a GaN bulk crystal containing GaN is a wide band-gap semiconductor which crystallizes in the hexagonal wurtzite structure

  3. Cross-sectional Scanning Tunneling Microscopy and Spectroscopy of InGaP/GaAs Heterojunctions

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Cross-sectional Scanning Tunneling Microscopy and Spectroscopy of InGaP/GaAs Heterojunctions Y Abstract Compositionally abrupt InGaP/GaAs heterojunctions grown by gas-source molecular beam epitaxy have the InGaP layer show non-uniform In and Ga distribution. About 1.5 nm of transition region

  4. Role of Electrochemical Reactions in the Degradation Mechanisms of AlGaN/GaN HEMTs

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    Role of Electrochemical Reactions in the Degradation Mechanisms of AlGaN/GaN HEMTs Feng Gao1, USA tpalacios@mit.edu; (617) 324-2395 Keywords: AlGaN/GaN HEMTs, reliability, moisture, electro-chemical reactions Abstract The nature of structural degradation in AlGaN/GaN high electron mobility transistors

  5. Dopant-Free GaN/AlN/AlGaN Radial Nanowire Heterostructures as High

    E-Print Network [OSTI]

    Li, Yat

    Dopant-Free GaN/AlN/AlGaN Radial Nanowire Heterostructures as High Electron Mobility Transistors, 2006 ABSTRACT We report the rational synthesis of dopant-free GaN/AlN/AlGaN radial nanowire-organic chemical vapor deposition (MOCVD). Transmission electron microscopy (TEM) studies reveal that the GaN/ AlN/AlGaN

  6. Beta decay of Ga-62 

    E-Print Network [OSTI]

    Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.

    2003-01-01T23:59:59.000Z

    We report a study of the beta decay of Ga-62, whose dominant branch is a superallowed 0(+)-->0(+) transition to the ground state of Zn-62. We find the total half-life to be 115.84+/-0.25 ms. This is the first time that the Ga-62 half-life has been...

  7. Influence of GaAs surface termination on GaSb/GaAs quantum dot structure and band offsets

    SciTech Connect (OSTI)

    Zech, E. S.; Chang, A. S.; Martin, A. J.; Canniff, J. C.; Millunchick, J. M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Lin, Y. H. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)

    2013-08-19T23:59:59.000Z

    We have investigated the influence of GaAs surface termination on the nanoscale structure and band offsets of GaSb/GaAs quantum dots (QDs) grown by molecular-beam epitaxy. Transmission electron microscopy reveals both coherent and semi-coherent clusters, as well as misfit dislocations, independent of surface termination. Cross-sectional scanning tunneling microscopy and spectroscopy reveal clustered GaSb QDs with type I band offsets at the GaSb/GaAs interfaces. We discuss the relative influences of strain and QD clustering on the band offsets at GaSb/GaAs interfaces.

  8. Simple method for calculating island widths

    SciTech Connect (OSTI)

    Cary, J.R. (Department of Astrophysical, Planetary, and Atmospheric Sciences, and Department of Physics, University of Colorado, Boulder, Colorado 80309-0391 (USA)); Hanson, J.D. (Department of Physics, Auburn University, Auburn, Alabama 36849 (USA))

    1991-04-01T23:59:59.000Z

    A simple method for calculating magnetic island widths has been developed. This method uses only that information obtained from integrating along the closed field line at the island center. Thus, this method is computationally less intensive than the usual method of producing surfaces of section of sufficient detail to locate and resolve the island separatrix. This method has been implemented numerically and used to analyze the buss work islands of ATF (Fusion Technol. {bold 10}, 179 (1986)). In this case the method proves to be accurate to at least within 20% even though the islands are within a factor of 2 of overlapping.

  9. Magnetic island evolution in hot ion plasmas

    SciTech Connect (OSTI)

    Ishizawa, A.; Nakajima, N. [National Institute for Fusion Science, Toki 509-5292 (Japan); Waelbroeck, F. L.; Fitzpatrick, R.; Horton, W. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2012-07-15T23:59:59.000Z

    Effects of finite ion temperature on magnetic island evolution are studied by means of numerical simulations of a reduced set of two-fluid equations which include ion as well as electron diamagnetism in slab geometry. The polarization current is found to be almost an order of magnitude larger in hot than in cold ion plasmas, due to the strong shear of ion velocity around the separatrix of the magnetic islands. As a function of the island width, the propagation speed decreases from the electron drift velocity (for islands thinner than the Larmor radius) to values close to the guiding-center velocity (for islands of order 10 times the Larmor radius). In the latter regime, the polarization current is destabilizing (i.e., it drives magnetic island growth). This is in contrast to cold ion plasmas, where the polarization current is generally found to have a healing effect on freely propagating magnetic island.

  10. Pathogenicity island mobility and gene content.

    SciTech Connect (OSTI)

    Williams, Kelly Porter

    2013-10-01T23:59:59.000Z

    Key goals towards national biosecurity include methods for analyzing pathogens, predicting their emergence, and developing countermeasures. These goals are served by studying bacterial genes that promote pathogenicity and the pathogenicity islands that mobilize them. Cyberinfrastructure promoting an island database advances this field and enables deeper bioinformatic analysis that may identify novel pathogenicity genes. New automated methods and rich visualizations were developed for identifying pathogenicity islands, based on the principle that islands occur sporadically among closely related strains. The chromosomally-ordered pan-genome organizes all genes from a clade of strains; gaps in this visualization indicate islands, and decorations of the gene matrix facilitate exploration of island gene functions. A %E2%80%9Clearned phyloblocks%E2%80%9D method was developed for automated island identification, that trains on the phylogenetic patterns of islands identified by other methods. Learned phyloblocks better defined termini of previously identified islands in multidrug-resistant Klebsiella pneumoniae ATCC BAA-2146, and found its only antibiotic resistance island.

  11. Floating Cities, Islands and States

    E-Print Network [OSTI]

    Bolonkin, Alexander

    2008-01-01T23:59:59.000Z

    Many small countries are in need of additional territory. They build landfills and expensive artificial islands. The ocean covers 71 per cent of the Earth surface. Those countries (or persons of wealth) starting the early colonization of the ocean may obtain advantages through additional territory or creating their own independent state. An old idea is building a big ship. The best solution to this problem, however, is the provision of floating cities, islands, and states. The author idea is to use for floating cities, islands, and states a cheap floating platform created from a natural ice field taken from the Arctic or Antarctic oceans. These cheap platforms protected by air-film (bottom and sides) and a conventional insulating cover (top) and having a cooling system can exist for an unlimited time. They can be increased in number or size at any time, float in warm oceans, travel to different continents and countries, serve as artificial airports, harbors and other marine improvements, as well as floating c...

  12. Multiple-band-edge quantum-well intermixing in the InGaAs/InGaAsP/InGaP material system

    E-Print Network [OSTI]

    Coldren, Larry A.

    Multiple-band-edge quantum-well intermixing in the InGaAs/InGaAsP/InGaP material system Erik J InGaAs/InGaAsP/InGaP material system. © 2005 American Institute of Physics. DOI: 10 of achieving QWI in such active regions.3,4 However, InGaAs/InGaAsP/InGaP-based de- vices offer numerous

  13. A signature for turbulence driven magnetic islands

    SciTech Connect (OSTI)

    Agullo, O.; Muraglia, M.; Benkadda, S. [Aix-Marseille Université, CNRS, PIIM, UMR 7345 Marseille (France); France-Japan Magnetic Fusion Laboratory, LIA 336 CNRS, Marseille (France); Poyé, A. [Univ. Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33405 Talence (France); Yagi, M. [Plasma Theory and Simulation Gr., JAEA, Rokkasho (Japan); Garbet, X. [IRFM, CEA, St-Paul-Lez-Durance 13108 (France); Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2014-09-15T23:59:59.000Z

    We investigate the properties of magnetic islands arising from tearing instabilities that are driven by an interchange turbulence. We find that such islands possess a specific signature that permits an identification of their origin. We demonstrate that the persistence of a small scale turbulence maintains a mean pressure profile, whose characteristics makes it possible to discriminate between turbulence driven islands from those arising due to an unfavourable plasma current density gradient. We also find that the island poloidal turnover time, in the steady state, is independent of the levels of the interchange and tearing energy sources. Finally, we show that a mixing length approach is adequate to make theoretical predictions concerning island flattening in the island rotation frame.

  14. GaInNAs laser gain

    SciTech Connect (OSTI)

    CHOW,WENG W.; JONES,ERIC D.; MODINE,NORMAND A.; KURTZ,STEVEN R.; ALLERMAN,ANDREW A.

    2000-05-23T23:59:59.000Z

    The optical gain spectra for GaInNAs/GaAs quantum wells are computed using a microscopic laser theory. From these spectra, the peak gain and carrier radiative decay rate as functions of carrier density are determined. These dependences allow the study of the lasing threshold current density of GaInNAs/GaAs quantum well structures.

  15. Red emitting photonic devices using InGaP/InGaAlP material system

    E-Print Network [OSTI]

    Kangude, Yamini

    2005-01-01T23:59:59.000Z

    In this thesis, two red emitting photonic devices are presented using the InGaP/InGaAlP material system. InGaP/InGaAlP material system provides large flexibility in the band gap energy while being lattice matched to GaAs ...

  16. ANNUAL WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    ANNUAL WIND DATA REPORT Thompson Island March 1, 2002 ­ February 28, 2003 Prepared.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  17. WIND DATA REPORT Deer Island Outfall

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Deer Island Outfall August 18, 2003 ­ December 4, 2003 Prepared for Massachusetts...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 7 Wind Speed Distributions

  18. WIND DATA REPORT Deer Island Parking Lot

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Deer Island Parking Lot May 1, 2003 ­ July 15, 2003 Prepared for Massachusetts...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 7 Wind Speed Distributions

  19. Nauru Island Effect Detection Data Set

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Long, Chuck

    During Nauru99 it was noted that the island was producing small clouds that advected over the ARM site. The Nauru Island Effect Study was run for 1.5 years and the methodology developed to detect the occurrence. Nauru ACRF downwelling SW, wind direction, and air temperature data are used, along with downwelling SW data from Licor radiometers located on the southern end of the island near the airport landing strip. A statistical analysis and comparison of data from the two locations is used to detect the likely occurrence of an island influence on the Nauru ACRF site data

  20. Pennsylvania Nuclear Profile - Three Mile Island

    U.S. Energy Information Administration (EIA) Indexed Site

    Three Mile Island" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

  1. Asian American Pacific Islander Heritage Month

    Broader source: Energy.gov [DOE]

    Generations of Asian Americans and Pacific Islanders (AAPIs) have helped make America what it is today. Their histories recall bitter hardships and proud accomplishments -- from the laborers who...

  2. Dendrochronology of Strain-Relaxed Islands

    SciTech Connect (OSTI)

    Merdzhanova, T.; Kiravittaya, S.; Rastelli, A.; Stoffel, M.; Denker, U.; Schmidt, O.G. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)

    2006-06-09T23:59:59.000Z

    We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes.

  3. Simple method for calculating island widths

    SciTech Connect (OSTI)

    Cary, J.R.; Hanson, J.D.; Carreras, B.A.; Lynch, V.E.

    1989-01-01T23:59:59.000Z

    A simple method for calculating magnetic island widths has been developed. This method uses only information obtained from integrating along the closed field line at the island center. Thus, this method is computationally less intensive than the usual method of producing surfaces of section of sufficient detail to locate and resolve the island separatrix. This method has been implemented numerically and used to analyze the buss work islands of ATF. In this case the method proves to be accurate to at least within 30%. 7 refs.

  4. Northern Mariana Islands - Territory Energy Profile Overview...

    U.S. Energy Information Administration (EIA) Indexed Site

    islands of Pagan and Saipan - unique in Micronesia in having abundant geothermal energy potential, and CNMI has excellent resources for both wind and solar power. CNMI enacted a...

  5. Aeromagnetic Survey And Interpretation, Ascention Island, South...

    Open Energy Info (EERE)

    Interpretation, Ascention Island, South Atlantic Ocean Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Aeromagnetic Survey And Interpretation,...

  6. Morphological barrier island changes and recovery of dunes after Hurricane Dennis, St. George Island, Florida

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    of the barrier island are analyzed, along with the short-term post-storm recovery of secondary dunes. ResultsMorphological barrier island changes and recovery of dunes after Hurricane Dennis, St. George September 2009 Keywords: Dune recovery LiDAR Overwash Hurricane Dennis Barrier island During the summer

  7. AlGaAs/InGaAs/AlGaAs Double Barrier

    E-Print Network [OSTI]

    Perera, A. G. Unil

    -state Er. Tunneling Quantum Dot Sensors for Multi-band Infrared and Terahertz Radiation Detection G radiation detection are demonstrated. In T-QDIP structures, photoabsorption takes place in InGaAs QDs (due

  8. HEALTH EFFECTS OF THE NUCLEAR ACCIDENT AT THREE MILE ISLAND

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01T23:59:59.000Z

    Commission on the Accident at Three Mile Island (Fabrikant,Commission on the Accident at Three Mile Island. (Fahrikant,Commission on the Accident at Three Mile Island. (Fabrikant,

  9. The dynamics of genetic and morphological variation on volcanic islands

    E-Print Network [OSTI]

    Thorpe, Roger Stephen

    : volcanism; phylogeography; geographical variation; natural selection; Canary islands; Tarentola 1 and Canary islands). It has been argued that population extinctions, recolonizations and associ- ated a role in shaping geographical variation. The islands of the Canary Archipelago provide an excellent

  10. Rhode Island to Build First Offshore Wind Farm

    Broader source: Energy.gov [DOE]

    Block Island, a small town with only 1,000 full-time, residents, is the site for a big project, when it will become home to Rhode Island’s first offshore wind farm.

  11. Monhegan Island | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose BendMiasole IncMinuteman WindMoana(Tempel,MoeMonhegan Island Jump

  12. Island Gas | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunanInformation sourceInvensysIsland Gas Jump to: navigation,

  13. Composition and Interface Analysis of InGaN/GaN Multiquantum...

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

    Composition and Interface Analysis of InGaNGaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography. Composition and Interface Analysis of InGaNGaN Multiquantum-Wells...

  14. GaAs, AlGaAs and InGaP Tunnel Junctions for Multi-Junction Solar Cells Under Concentration: Resistance Study

    SciTech Connect (OSTI)

    Wheeldon, Jeffrey F.; Valdivia, Christopher E.; Walker, Alex; Kolhatkar, Gitanja; Hall, Trevor J.; Hinzer, Karin [Centre for Research in Photonics, University of Ottawa, Ottawa, ON (Canada); Masson, Denis; Riel, Bruno; Fafard, Simon [Cyrium Technologies Inc., Ottawa, ON (Canada); Jaouad, Abdelatif; Turala, Artur; Ares, Richard; Aimez, Vincent [Centre de Recherche en Nanofabrication et en Nanocaracterisation CRN2, Universite de Sherbrooke, Sherbrooke, QC (Canada)

    2010-10-14T23:59:59.000Z

    The following four TJ designs, AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs are studied to determine minimum doping concentration to achieve a resistance of <10{sup -4} {omega}{center_dot}cm{sup 2} and a peak tunneling current suitable for MJ solar cells up to 1500-suns concentration (operating current of 21 A/cm{sup 2}). Experimentally calibrated numerical models are used to determine how the resistance changes as a function of doping concentration. The AlGaAs/GaAs TJ design is determined to require the least doping concentration to achieve the specified resistance and peak tunneling current, followed by the GaAs/GaAs, and AlGaAs/AlGaAs TJ designs. The AlGaAs/InGaP TJ design can only achieve resistances >5x10{sup -4} {omega}cm{sup 2}.

  15. PRESSURE DEPENDENCE OF OPTICAL TRANSITIONS IN InGaN/GaN MULTIPLE QUANTUM WELLS

    E-Print Network [OSTI]

    McCluskey, Matthew

    -µm thick GaN layer deposited on a sapphire substrate, and it is capped by a 0.2-µm GaN:Mg pPRESSURE DEPENDENCE OF OPTICAL TRANSITIONS IN InGaN/GaN MULTIPLE QUANTUM WELLS W. Shan,* J.W. Ager pressure on optical transitions in InGaN/GaN multiple quantum wells (MQWs) has been studied

  16. Free carrier accumulation at cubic AlGaN/GaN heterojunctions Q. Y. Wei,1

    E-Print Network [OSTI]

    As, Donat Josef

    ) substrate,7 with GaN and AlGaN layer thickness of 600 nm and 30 nm, respectively. The layer thicknessFree carrier accumulation at cubic AlGaN/GaN heterojunctions Q. Y. Wei,1 T. Li,1 J. Y. Huang,1 F. A (Received 24 February 2012; accepted 19 March 2012; published online 3 April 2012) Cubic Al0.3Ga0.7N/GaN

  17. news: Bern Convention group of experts on European island biological diversity: an international network to preserve island biodiversity

    E-Print Network [OSTI]

    Borges, Paulo A. V.

    2009-01-01T23:59:59.000Z

    by the Government of Canary Islands at Tenerife (1-3 Octoberthe Gov- ernments of Canary Islands, Azores and Madeira inAzores, Madeira and Canary Islands (Macaronesia), Balearic

  18. The Long Island Solar Farm | Department of Energy

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

    of Energy The Long Island Solar Farm More Documents & Publications The Long Island Solar Farm EA-1663: Final Environmental Assessment EA-1928: Final Environmental Assessment...

  19. The Long Island Solar Farm | Department of Energy

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

    in the East. The Long Island Solar Farm More Documents & Publications The Long Island Solar Farm EA-1663: Final Environmental Assessment EA-1928: Final Environmental Assessment...

  20. asian pacific islanders: Topics by E-print Network

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

    Department of Mangroves of the Pacific Islands:Agriculture Environmental Sciences and Ecology Websites Summary: . The perception of mangroves by people in the Pacific islands...

  1. Commercial-Scale Renewable-Energy Grants (Rhode Island)

    Broader source: Energy.gov [DOE]

    The Rhode Island Economic Development Corporation (RIEDC) provides incentives for renewable-energy projects. Incentive programs are funded by the Rhode Island Renewable Energy Fund (RIREF) and...

  2. Energy Transformation in the U.S. Virgin Islands | Department...

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

    About Us Initiatives & Projects Energy Transition Initiative Energy Transformation in the U.S. Virgin Islands Energy Transformation in the U.S. Virgin Islands Click on the...

  3. amchitka island alaska: Topics by E-print Network

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

    MA August 2005 Prepared for Massachusetts for August 2005 This update summarizes the monthly data results for the Thompson Island monitoring site Island for the month of August...

  4. adak island alaska: Topics by E-print Network

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

    MA August 2005 Prepared for Massachusetts for August 2005 This update summarizes the monthly data results for the Thompson Island monitoring site Island for the month of August...

  5. akutan island alaska: Topics by E-print Network

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

    MA August 2005 Prepared for Massachusetts for August 2005 This update summarizes the monthly data results for the Thompson Island monitoring site Island for the month of August...

  6. The Biogeography of Globally Threatened Seabirds and Island Conservation Opportunities

    E-Print Network [OSTI]

    Spatz, Dena R.

    2013-01-01T23:59:59.000Z

    and North Islands, Hispaniola, etc. ). The conservation ofand North Islands, Hispaniola, etc. ). The conservation ofGreater Antilles (Hispaniola) Lesser Antilles Galapagos

  7. Observation of energetic electrons within magnetic islands

    E-Print Network [OSTI]

    Loss, Daniel

    that energetic electron fluxes peak at sites of compressed density within islands, which imposes a new constraintLETTERS Observation of energetic electrons within magnetic islands L.-J. CHEN1 *, A. BHATTACHARJEE1, University of New Hampshire, Durham, New Hampshire 03824, USA 2 National Astronomical Observatory of Japan, 2

  8. InGaP/GaAs/InGaP double-heterojunction bipolar transistors grown by solid-source molecular-beam epitaxy with a valved phosphorus cracker

    E-Print Network [OSTI]

    Woodall, Jerry M.

    InGaP/GaAs/InGaP double-heterojunction bipolar transistors grown by solid-source molecular; accepted 17 November 1995 The growth and device characterization of an InGaP/GaAs double-quality phosphorus-containing compounds.1­4 The growth of high-performance InGaP/ GaAs and InGaAs/InP single

  9. InGaP/InGaAsN/GaAs NpN double-heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Chang, P. C. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Baca, A. G. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Li, N. Y. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States)] [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Xie, X. M. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States)] [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Hou, H. Q. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States)] [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Armour, E. [Emcore Corporation, Somerset, New Jersey 08873 (United States)] [Emcore Corporation, Somerset, New Jersey 08873 (United States)

    2000-04-17T23:59:59.000Z

    We have demonstrated a functional NpN double-heterojunction bipolar transistor (DHBT) using InGaAsN for the base layer. The InGaP/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs DHBT has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in a InGaP/GaAs heterojunction bipolar transistor (HBT). The lower turn-on voltage is attributed to the smaller band gap (1.20 eV) of metalorganic chemical vapor deposition-grown In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} base layer. GaAs is used for the collector; thus the breakdown voltage (BV{sub CEO}) is 10 V, consistent with the BV{sub CEO} of InGaP/GaAs HBTs of comparable collector thickness and doping level. To alleviate the current blocking phenomenon caused by the larger conduction band discontinuity between InGaAsN and GaAs, a graded InGaAs layer with {delta} doping is inserted at the base-collector junction. The improved device has a peak current gain of seven with ideal current-voltage characteristics. (c) 2000 American Institute of Physics.

  10. InGaP/InGaAsN/GaAs NpN double heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Chang, P.C.; Baca, A.G.; Li, N.Y.; Xie, X.M.; Sharps, P.R.; Hou, H.Q.

    2000-01-10T23:59:59.000Z

    The authors have demonstrated a functional NpN double heterojunction bipolar transistor (DHBT) using InGaAsN for base layer. The InGaP/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs DHBT has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in a InGaP/GaAs HBT. The lower V{sub ON} is attributed to the smaller bandgap (E{sub g}=1.20eV) of MOCVD grown In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} base layer. GaAs is used for the collector; thus the BV{sub CEO} is 10 V, consistent with the BV{sub CEO} of InGaP/GaAs Hbts of comparable collector thickness and doping level. To alleviate the current blocking phenomenon caused by the larger {triangle}E{sub C} between InGaAsN and GaAs, a graded InGaAs layer with {delta}-doping is inserted at the base-collector junction. The improved device has a peak current gain of 7 with ideal IV characteristics.

  11. Intrafacet migration effects in InGaN/GaN structures grown on triangular GaN ridges studied by submicron beam x-ray diffraction

    E-Print Network [OSTI]

    Sirenko, Andrei

    Intrafacet migration effects in InGaN/GaN structures grown on triangular GaN ridges studied for x-ray diffraction and reciprocal space mapping of InGaN/GaN multiple-quantum-well MQW structures grown on the sidewalls of 10- m-wide triangular GaN ridges with 1-1.1 facets. Samples were produced

  12. GaN0.011P0.989–GaP Double-Heterostructure Red Light-Emitting Diodes Directly Grown on GaP Substrates

    E-Print Network [OSTI]

    Tu, Charles W

    2000-01-01T23:59:59.000Z

    and C. W. Tu, GaN diodes on GaP substrates, 2000. [7] J. W.on a GaN directly grown on a GaP substrate was successfullyDH) directly a GaN grown on a (100) GaP substrate. Fig. 1(a)

  13. AlGaAs/InGaAsN/GaAs PnP double heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Chang, P.C.; Baca, A.G.; Li, N.Y.; Sharps, P.R.; Hou, H.Q.; Laroche, J.R.; Ren, F.

    2000-01-11T23:59:59.000Z

    The authors have demonstrated a functional MOCVD-grown AlGaAs/InGaAsN/GaAsPnP DHBT that is lattice matched to GaAs and has a peak current gain ({beta}) of 25. Because of the smaller bandgap (E{sub g}=1.20eV)of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} used for the base layer, this device has a low V{sub ON} of 0.79 V, 0.25 V lower than in a comparable Pnp AlGaAs/GaAs HBT. The BV{sub CEO} is 12 V, consistent with its GaAs collector thickness and doping level.

  14. Asymmetric interfacial abruptness in N-polar and Ga-polar GaN/AlN/GaN heterostructures

    SciTech Connect (OSTI)

    Mazumder, B.; Hurni, C. A.; Zhang, J. Y.; Speck, J. S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Wong, M. H.; Mishra, U. K. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

    2012-08-27T23:59:59.000Z

    In this letter, we report on the interfacial abruptness of GaN/AlN/GaN heterostructures with pulsed laser atom probe tomography (APT). The samples were grown by plasma-assisted molecular beam epitaxy (MBE) under both metal-rich and N-rich conditions on both Ga-polar (0001) GaN templates and N-polar (0001) GaN substrates. An NH{sub 3} assisted MBE technique was involved to grow similar Ga-polar and N-polar structures on GaN:Fe substrates and GaN/Al{sub 2}O{sub 3} templates, respectively, for a comparison study. We find in all cases the interface with net positive polarization charge was chemically abrupt, whereas the interface with net negative polarization charge was diffuse. We discuss the implications on device design and performance. These data validate the efficiency of APT in studying interfaces for better performance in devices.

  15. Superior radiation-resistant properties of InGaP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Yamaguchi, M.; Okuda, T.; Taylor, S.J.; Takamoto, T. [Toyota Technological Institute 2-12-1 Hisakata, Tempaku, Nagoya 468 (Japan)] [Toyota Technological Institute 2-12-1 Hisakata, Tempaku, Nagoya 468 (Japan); Ikeda, E.; Kurita, H. [Central Resource Laboratory, Japan Energy Company, Niizo-Minami, Toda, Saitama 335 (Japan)] [Central Resource Laboratory, Japan Energy Company, Niizo-Minami, Toda, Saitama 335 (Japan)

    1997-03-01T23:59:59.000Z

    The observation of minority-carrier injection-enhanced annealing of radiation damage to InGa{sub 0.5}P{sub 0.5}/GaAs tandem solar cells is reported. Radiation resistance of InGaP/GaAs tandem solar cells as is similar with GaAs-on-Ge cells have been confirmed with 1 MeV electron irradiations. Moreover, minority-carrier injection under light illumination and forward bias conditions is shown to enhance defect annealing in InGaP and to result in the recovery of InGaP/GaAs tandem solar cell properties. These results suggest that the InGaP/GaAs(/Ge) multijunction solar cells and InGaP-based devices have great potential for space applications. {copyright} {ital 1997 American Institute of Physics.}

  16. Beta decay of Ga-62

    E-Print Network [OSTI]

    Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.

    2003-01-01T23:59:59.000Z

    from the ex- perimental ft value for a 01?01 b decay between analog states with the relation @3# 0556-2813/2003/68~1!/015501~6!/$20.00 68 015501- of 62Ga . Hardy, V. E. Mayes, R. G. Neilson, M. Sanchez-Vega, and R. E. Tribble y, College Station...

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

    E-Print Network [OSTI]

    Espinosa, Horacio D.

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

  18. Self-aligned AlGaN/GaN transistors for sub-mm wave applications

    E-Print Network [OSTI]

    Saadat, Omair I

    2010-01-01T23:59:59.000Z

    This thesis describes work done towards realizing self-aligned AlGaN/GaN high electron mobility transistors (HEMTs). Self-aligned transistors are important for improving the frequency of AlGaN/GaN HEMTs by reducing source ...

  19. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA June 2005 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA at Thompson Island for the month of June 2005, at the highest anemometer height of 40 m. Thompson Island Wind

  20. Invited Paper GaN HEMT reliability

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    Invited Paper GaN HEMT reliability J.A. del Alamo *, J. Joh Microsystems Technology Laboratories mechanism recently identified in GaN high-electron mobility transistors subject to electrical stress. Under high voltage, it has been found that electrically active defects are generated in the AlGaN barrier

  1. New GaInP/GaAs/GaInAs, Triple-Bandgap, Tandem Solar Cell for High-Efficiency Terrestrial Concentrator Systems

    SciTech Connect (OSTI)

    Kurtz, S.; Wanlass, M.; Kramer, C.; Young, M.; Geisz, J.; Ward, S.; Duda, A.; Moriarty, T.; Carapella, J.; Ahrenkiel, P.; Emery. K.; Jones, K.; Romero, M.; Kibbler, A.; Olson, J.; Friedman, D.; McMahon, W.; Ptak, A.

    2005-11-01T23:59:59.000Z

    GaInP/GaAs/GaInAs three-junction cells are grown in an inverted configuration on GaAs, allowing high quality growth of the lattice matched GaInP and GaAs layers before a grade is used for the 1-eV GaInAs layer. Using this approach an efficiency of 37.9% was demonstrated.

  2. InAs=InGaP=GaAs heterojunction power Schottky rectifiers

    E-Print Network [OSTI]

    Woodall, Jerry M.

    InAs=InGaP=GaAs heterojunction power Schottky rectifiers A. Chen, M. Young and J.M. Woodall A low-matched InGaP on GaAs, to make a high-temperature power rectifier. The LT molecular beam epitaxy technique enables the formation of an abrupt interface between InAs and InGaP. This heterojunction rectifier

  3. Monolithic Millimeter-wave Distributed Amplifiers using AlGaN/GaN HEMTs

    E-Print Network [OSTI]

    York, Robert A.

    Monolithic Millimeter-wave Distributed Amplifiers using AlGaN/GaN HEMTs Rajkumar Santhakumar, Yi have been designed and fabricated using AlGaN/GaN HEMTs. One of them uses a standard HEMT for the unit-gate distributed amplifier achieves a CW peak output power of 1W and a PAE of about 16% at 4GHz. Index Terms -- GaN

  4. Role of strain in polarization switching in semipolar InGaN/GaN quantum wells

    E-Print Network [OSTI]

    Role of strain in polarization switching in semipolar InGaN/GaN quantum wells Qimin Yan,1,a Patrick November 2010 The effect of strain on the valence-band structure of 112¯2 semipolar InGaN grown on GaN D6 is calculated for GaN and InN using density functional theory with the Heyd­Scuseria­ Ernzerhof

  5. GaN/AlGaN heterojunction infrared detector responding in 814 and 2070 m ranges

    E-Print Network [OSTI]

    Perera, A. G. Unil

    GaN/AlGaN heterojunction infrared detector responding in 8­14 and 20­70 m ranges G. Ariyawansa, M October 2006 A GaN/AlGaN heterojunction interfacial work function internal photoemission infrared detector, the work demonstrates 54 m 5.5 THz operation of the detector based on 1s­2p± transition of Si donors in GaN

  6. Elba Island, GA LNG Imports (Price) from Qatar (Dollars per Thousand Cubic

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469DecadeOrigin State1,237 1,471Cubic

  7. Elba Island, GA LNG Imports (Price) from Qatar (Dollars per Thousand Cubic

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469DecadeOrigin State1,237 1,471CubicFeet) Year Jan

  8. Elba Island, GA Liquefied Natural Gas Imports from Qatar (Million Cubic

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469DecadeOrigin State1,237 1,471CubicFeet) Year

  9. Elba Island, GA Liquefied Natural Gas Total Imports (Million Cubic Feet)

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469DecadeOrigin State1,237 1,471CubicFeet) YearTotal

  10. Elba Island, GA Natural Gas Liquefied Natural Gas Imports from Egypt

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469DecadeOrigin State1,237 1,471CubicFeet)

  11. Elba Island, GA Natural Gas Liquefied Natural Gas Imports from Trinidad and

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469DecadeOrigin State1,237 1,471CubicFeet)Tobago

  12. Price of Elba Island, GA Liquefied Natural Gas Total Imports (Dollars per

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousand CubicThousandCubic

  13. Price of Elba Island, GA Liquefied Natural Gas Total Imports (Dollars per

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousand CubicThousandCubicThousand

  14. Price of Elba Island, GA Natural Gas LNG Imports from Egypt (Nominal

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousand

  15. Price of Elba Island, GA Natural Gas LNG Imports from Egypt (Nominal

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousandDollars per Thousand Cubic

  16. Price of Elba Island, GA Natural Gas LNG Imports from Equatorial Guinea

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousandDollars per Thousand

  17. Price of Elba Island, GA Natural Gas LNG Imports from Nigeria (Nominal

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousandDollars per ThousandDollars per

  18. Price of Elba Island, GA Natural Gas LNG Imports from Trinidad and Tobago

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousandDollars per ThousandDollars

  19. Price of Elba Island, GA Natural Gas LNG Imports from Trinidad and Tobago

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYearperThousandDollars per

  20. U.S. Virgin Islands- Net Metering

    Broader source: Energy.gov [DOE]

    In February 2007, the U.S. Virgin Islands Public Services Commission approved a limited net-metering program for residential and commercial photovoltaic (PV), wind-energy or other renewable energ...

  1. Qualifying RPS State Export Markets (Rhode Island)

    Broader source: Energy.gov [DOE]

    This entry lists the states with Renewable Portfolio Standard (RPS) policies that accept generation located in Rhode Island as eligible sources towards their RPS targets or goals. For specific...

  2. 11 Life on Herbert Island (part 2)

    E-Print Network [OSTI]

    Leonard, Stephen Pax

    last updated on Monday, 4 April 2011 Accession Form for Individual Recordings: Collection / Collector Name Stephen Leonard Tape No. / Track / Item No. 11 Length of track 45 minutes Title of track Life on Herbert Island (part 2) Translation...

  3. 13 Life on Herbert Island (part 3)

    E-Print Network [OSTI]

    Leonard, Stephen Pax

    last updated on Monday, 4 April 2011 Accession Form for Individual Recordings: Collection / Collector Name Stephen Leonard Tape No. / Track / Item No. 13 Length of track 30 minutes Title of track Life on Herbert Island (part 3) Translation...

  4. 12 Life on Herbert Island (part 1)

    E-Print Network [OSTI]

    Leonard, Stephen Pax

    last updated on Monday, 4 April 2011 Accession Form for Individual Recordings: Collection / Collector Name Stephen Leonard Tape No. / Track / Item No. 12 Length of track 1 hour 35 minutes Title of track Life on Herbert Island (part 1...

  5. Community Redevelopment Case Study: Jekyll Island

    Broader source: Energy.gov [DOE]

    Presentation—given at the April 2012 Federal Utility Partnership Working Group (FUPWG) meeting—features photos from a case study about Jekyll Island's community redevelopment project in Georgia.

  6. Alternative Fuels Data Center: Rhode Island Information

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    facilities in Rhode Island, use the TransAtlas interactive mapping tool or use BioFuels Atlas to show the use and potential production of biofuels throughout the U.S. and...

  7. Solar School Program in Reunion Island

    E-Print Network [OSTI]

    David, M.; Adelard, L.

    2004-01-01T23:59:59.000Z

    system efficiency. In Réunion Island, the industrial engineering laboratory is involved in the regional solar school program. Its aim is to gather some local construction actors (city technical offices, architects, civil engineers, specialized university...

  8. The Jobs Development Act (Rhode Island)

    Broader source: Energy.gov [DOE]

    The Jobs Development Act provides an incremental reduction in the corporate income tax rate (9%) to companies creating jobs in Rhode Island. For every ten new jobs created for companies with fewer...

  9. Job Creation Guaranty Program (Rhode Island)

    Broader source: Energy.gov [DOE]

    RIEDC’s Job Creation Guaranty Program provides businesses looking to expand or relocate in Rhode Island with access to capital and credit. RIEDC guarantees loans by private lenders or guarantees...

  10. CAYMAN ISLANDS National Biodiversity Action Plan

    E-Print Network [OSTI]

    Exeter, University of

    down to us by those who went before, the natural wealth and beauty which is ours. John F. Kennedy environment for the Cayman Islands. CH2M Hill "Study on the Provision of Construction Aggregate and Fill

  11. Bainbridge Island Data Dashboard | Department of Energy

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

    The data dashboard for Bainbridge Island, a partner in the U.S. Department of Energy's Better Buildings Neighborhood Program. bban0003805pmcdashboardy13-q3.xls More Documents...

  12. Macroalgal distribution at Lee Stocking Island, Bahamas

    E-Print Network [OSTI]

    Roberts, Jill Christie

    1997-01-01T23:59:59.000Z

    from the reef community, macroalgae have been increasing in abundance on the reefs surrounding Lee Stocking Island (LSI), Bahamas. Macroalgal patches prevent coral recruitment and growth, thereby restructuring the reef. In such cases, coral and algal...

  13. DYER ISLAND CONSERVATION TRUST LETTER OF CONCERN

    E-Print Network [OSTI]

    de Villiers, Marienne

    ..........................................................................................................................8 4 GENERAL POTENTIAL IMPACTS OF THE NPS ON THE MARINE ENVIRONMENTDYER ISLAND CONSERVATION TRUST LETTER OF CONCERN ASSOCIATED WITH THE ESTABLISHMENT OF A NUCLEAR....................................................................................................................................6 3 THE MARINE ENVIRONMENT SURROUNDING BANTAMSKLIP

  14. US Virgin Islands renewable energy future

    E-Print Network [OSTI]

    Oldfield, Brian (Brian K.)

    2013-01-01T23:59:59.000Z

    The US Virgin Islands must face drastic changes to its electrical system. There are two problems with electricity production in the USVI-it's dirty and it's expensive. Nearly one hundred percent of the electricity in these ...

  15. Solar School Program in Reunion Island 

    E-Print Network [OSTI]

    David, M.; Adelard, L.

    2004-01-01T23:59:59.000Z

    Because of its particular geographic situation and relatively high altitude (3069 meters), Reunion Island is composed of a very large amount of micro-climates which have a direct impact on buildings' comfort, energy consumptions and renewable energy...

  16. N. Mariana Islands- Renewables Portfolio Standard

    Broader source: Energy.gov [DOE]

    The Commonwealth of the Northern Mariana Islands enacted its Renewables Portfolio Standard in September 2007, in which a certain percentage of its net electricity sales must come from renewable e...

  17. Long Island Power Authority- Renewable Electricity Goal

    Broader source: Energy.gov [DOE]

    As a municipal utility, the Long Island Power Authority (LIPA) is not obligated to comply with the [http://www.dsireusa.org/library/includes/incentive2.cfm?Incentive_Code=N... New York Renewable...

  18. Metromorphosis : evolution on the urban island

    E-Print Network [OSTI]

    Vezina, Kenrick (Kenrick Freitas)

    2011-01-01T23:59:59.000Z

    Cities are very much alive. Like islands, they provide a natural testing ground for evolution. With more than half of the world's population living in urban areas now, the influence cities have on the planet's life is ...

  19. PSEG Long Island- Renewable Electricity Goal

    Broader source: Energy.gov [DOE]

    As a municipal utility, the Long Island Power Authority (LIPA) is not obligated to comply with the New York Renewable Portfolio Standard (RPS). The LIPA Board of Trustees has nevertheless decided...

  20. Effect of buffer structures on AlGaN/GaN high electron mobility transistor reliability

    SciTech Connect (OSTI)

    Liu, L. [University of Florida, Gainesville; Xi, Y. Y. [University of Florida, Gainesville; Ren, F. [University of Florida; Pearton, S. J. [University of Florida; Laboutin, O. [Kopin Corporation, Taunton, MA; Cao, Yu [Kopin Corporation, Taunton, MA; Johnson, Wayne J. [Kopin Corporation, Taunton, MA; Kravchenko, Ivan I [ORNL

    2012-01-01T23:59:59.000Z

    AlGaN/GaN high electron mobility transistors (HEMTs) with three different types of buffer layers, including a GaN/AlGaN composite layer, or 1 or 2 lm GaN thick layers, were fabricated and their reliability compared. The HEMTs with the thick GaN buffer layer showed the lowest critical voltage (Vcri) during off-state drain step-stress, but this was increased by around 50% and 100% for devices with the composite AlGaN/GaN buffer layers or thinner GaN buffers, respectively. The Voff - state for HEMTs with thin GaN and composite buffers were 100 V, however, this degraded to 50 60V for devices with thick GaN buffers due to the difference in peak electric field near the gate edge. A similar trend was observed in the isolation breakdown voltage measurements, with the highest Viso achieved based on thin GaN or composite buffer designs (600 700 V), while a much smaller Viso of 200V was measured on HEMTs with the thick GaN buffer layers. These results demonstrate the strong influence of buffer structure and defect density on AlGaN/GaN HEMT performance and reliability.

  1. A Theological Argument for an Everett Multiverse

    E-Print Network [OSTI]

    Page, Don N

    2012-01-01T23:59:59.000Z

    Science looks for the simplest hypotheses to explain observations. Starting with the simple assumption that {\\em the actual world is the best possible world}, I sketch an {\\it Optimal Argument for the Existence of God}, that the sufferings in our universe would not be consistent with its being alone the best possible world, but the total world could be the best possible if it includes an omnipotent, omniscient, omnibenevolent God who experiences great value in creating and knowing a universe with great mathematical elegance, even though such a universe has suffering. God seems loathe to violate elegant laws of physics that He has chosen to use in His creation, such as Maxwell's equations for electromagnetism or Einstein's equations of general relativity for gravity within their classical domains of applicability, even if their violation could greatly reduce human suffering (e.g., from falls). If indeed God is similarly loathe to violate quantum unitarity (though such violations by judicious collapses of the w...

  2. 24 Everett Street Cambridge, MA 02138

    E-Print Network [OSTI]

    Gunawardena, Jeremy

    is disrupted during inflammatory bowel disease. Industry Experience 06/2014 - 08/2014 Software Developer, futures, swaps, and other exotic energy and agricultural derivatives. Implemented arbitrage-free Monte by using large datasets to quantify historic risk and propose new investment strategies. Publications T

  3. Everett, Washington: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 NoEurope BV Jump to: navigation, search

  4. Growth of AlGaN/GaN heterojunction field effect transistors on semi-insulating GaN using an AlGaN interlayer

    SciTech Connect (OSTI)

    Chen, Z.; Denbaars, S. P. [Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States); Materials Department, University of California, Santa Barbara, California 93106 (United States); Pei, Y.; Newman, S.; Chu, R.; Brown, D.; Keller, S.; Mishra, U. K. [Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States); Chung, R.; Nakamura, S. [Materials Department, University of California, Santa Barbara, California 93106 (United States)

    2009-03-16T23:59:59.000Z

    Semi-insulating (SI) GaN layers were grown on 4H-SiC substrates by inserting an AlGaN layer between the AlN buffer and the GaN layer. Secondary ion mass spectroscopy measurements showed that the AlGaN layer prevented Si from diffusing from the substrate into the GaN layer. X-ray diffraction and atomic force microscopy analyses showed that an optimized AlGaN interlayer does not degrade the crystal quality or surface morphology of the SI GaN. The room temperature mobility of an AlGaN/GaN heterostructure using this SI GaN was 2200 cm{sup 2}/V s. High electron mobility transistors (HEMTs) with 0.65 {mu}m long gates were also fabricated on these SI GaN buffers. A power density of 19.0 W/mm with a power added efficiency of 48% was demonstrated at 10 GHz at a drain bias of 78 V. These HEMTs also exhibited sharp pinch off, low leakage, and negligible dispersion.

  5. Strain variations in InGaAsP/InGaP superlattices studied by scanning probe microscopy

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Strain variations in InGaAsP/InGaP superlattices studied by scanning probe microscopy Huajie Chen, Kista, Sweden Abstract Strain-compensated InGaAsP/InGaP superlattices are studied in cross- section. The strain compensated InGaAsP/InGaP/InP superlattices studied here have application for light sources

  6. AlGaN/GaN Metal Oxide Semiconductor Field Effect Transistors using Titanium Dioxide P. J. HANSEN

    E-Print Network [OSTI]

    York, Robert A.

    AlGaN/GaN Metal Oxide Semiconductor Field Effect Transistors using Titanium Dioxide P. J. HANSEN 1 epitaxially on AlGaN/GaN HFET structures by molecular beam epitaxy (MBE). Growth was first performed on GaN templates to establish epitaxial growth conditions. X-ray diffraction showed [001] TiO2 || [1010]GaN

  7. AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium titanate

    E-Print Network [OSTI]

    York, Robert A.

    AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium; published 13 October 2004) Use of high-k gate dielectrics in AlGaN/GaN heterostructure field transconductance and pinchoff voltage. To achieve this, AlGaN/GaN metal-oxide-semiconductor heterostructure field

  8. In this paper, an AlGaN/GaN high electron mobility transistor (HEMT) device based on a

    E-Print Network [OSTI]

    Yang, Kyounghoon

    205 Abstract In this paper, an AlGaN/GaN high electron mobility transistor (HEMT) device basedBm at 2 GHz have been demonstrated from the fabricated device. 1. Introduction In recent years, AlGaN/GaN noise amplifier and switch. Superior results have been reported in microwave power performance of AlGaN/GaN

  9. A New Architecture for AlGaN/GaN HEMT Frequency Doubler Using Active Integrated Antenna Design Approach

    E-Print Network [OSTI]

    Itoh, Tatsuo

    A New Architecture for AlGaN/GaN HEMT Frequency Doubler Using Active Integrated Antenna Design presents a new architecture for an AlGaN/GaN HEMT frequency doubler using the active integrated antenna. The antenna operates as a fundamental frequency reflector in this circuit. Using AlGaN/GaN with 1mm gate

  10. Generation-Recombination Defects In AlGaN/GaN HEMT On SiC Substrate,

    E-Print Network [OSTI]

    Boyer, Edmond

    Generation-Recombination Defects In AlGaN/GaN HEMT On SiC Substrate, Evidenced By Low Frequency Aristide Briand, 92.195 Meudon, France Abstract. Wide bandgap devices such as AlGaN/GaN High Electron of GR- bulges related respectively to AlGaN/GaN interface and quantum well are identified. Each GR

  11. Effect of dislocations on electron mobility in AlGaN/GaN and AlGaN/AlN/GaN heterostructures

    SciTech Connect (OSTI)

    Kaun, Stephen W.; Burke, Peter G.; Kyle, Erin C. H.; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Wong, Man Hoi; Mishra, Umesh K. [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)

    2012-12-24T23:59:59.000Z

    Al{sub x}Ga{sub 1-x}N/GaN (x = 0.06, 0.12, 0.24) and AlGaN/AlN/GaN heterostructures were grown on 6 H-SiC, GaN-on-sapphire, and free-standing GaN, resulting in heterostructures with threading dislocation densities of {approx}2 Multiplication-Sign 10{sup 10}, {approx}5 Multiplication-Sign 10{sup 8}, and {approx}5 Multiplication-Sign 10{sup 7} cm{sup -2}, respectively. All growths were performed under Ga-rich conditions by plasma-assisted molecular beam epitaxy. Dominant scattering mechanisms with variations in threading dislocation density and sheet concentration were indicated through temperature-dependent Hall measurements. The inclusion of an AlN interlayer was also considered. Dislocation scattering contributed to reduced mobility in these heterostructures, especially when sheet concentration was low or when an AlN interlayer was present.

  12. High efficiency InGaP solar cells for InGaP/GaAs tandem cell application

    SciTech Connect (OSTI)

    Takamoto, T.; Ikeda, E.; Kurita, H.; Ohmori, M. [Japan Energy Corp., Toda, Saitama (Japan). Central Research Lab.

    1994-12-31T23:59:59.000Z

    In this paper, high conversion efficiency single junction InGaP solar cells with n-p-p{sup +} structure are presented and their application to InGaP/GaAs monolithic tandem cells is discussed. In the InGaP cells, a best conversion efficiency of 18.48% was achieved by introducing the p{sup +} peak back surface field (BSF) layer with a high carrier concentration of 2 {times} 10{sup 18} cm{sup {minus}3}, which improved both short circuit current (Isc) and open circuit voltage (Voc). However, in the case of InGaP/GaAs tandem cells, a decrease in carrier concentration of the InGaP BSF layer, which was caused by the diffusion of Zn, was found to reduce the Isc and Voc of the tandem cell. The reduction in the carrier concentration was suppressed by using a thicker BSF layer of 0.5 {micro}m, which reduced the current density in the GaAs bottom cell. An InGaP/GaAs tandem cell with 27.3% efficiency and a high Voc of 2.418 V was obtained.

  13. Relaxed, high-quality InP on GaAs by using InGaAs and InGaP graded buffers to avoid phase separation

    E-Print Network [OSTI]

    Relaxed, high-quality InP on GaAs by using InGaAs and InGaP graded buffers to avoid phaseAs was 70% of that on bulk InP at both temperatures. To achieve this, graded buffers in the InGaAs, InGaP

  14. AlGaN/GaN HEMTs grown by Molecular Beam Epitaxy on sapphire, Sic, and HVPE GaN templates

    E-Print Network [OSTI]

    Manfra, Michael J.

    PS-4 AlGaN/GaN HEMTs grown by Molecular Beam Epitaxy on sapphire, Sic, and HVPE GaN templates Nils ABSTRACT Molecular Beam Epitaxy of GaN and related alloys is becoming a rival to the more established, and HVPE SI-GaN templates on sapphire. While sapphire and SI-Sic are established substrates for the growth

  15. ZrO2 gate dielectrics produced by ultraviolet ozone oxidation for GaN and AlGaN/GaN transistors

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    MOSCAP process ?ow: n-GaN substrate; Ohmic metallization andtion for a AlGaN/ GaN HEMT on a substrate which has a poorsapphire substrate, a well-passivated AlGaN/ GaN HEMT grown

  16. Lattice-engineered Si{sub 1-x}Ge{sub x}-buffer on Si(001) for GaP integration

    SciTech Connect (OSTI)

    Skibitzki, Oliver, E-mail: skibitzki@ihp-microelectronics.com; Zaumseil, Peter; Yamamoto, Yuji; Andreas Schubert, Markus [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Paszuk, Agnieszka; Hannappel, Thomas [Technische Universität Ilmenau, Gustav-Kirchhoff-Str. 5, 98693 Ilmenau (Germany); Hatami, Fariba; Ted Masselink, W. [Institut für Physik, Humboldt Universität zu Berlin, Newtonstrasse 15, 12489 Berlin (Germany); Trampert, Achim [Paul Drude Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Tillack, Bernd [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Technische Universität Berlin, HFT4, Einsteinufer 25, 10587 Berlin (Germany); Schroeder, Thomas [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Brandenburgische Technische Universität, Konrad-Zuse Str. 1, 03046 Cottbus (Germany)

    2014-03-14T23:59:59.000Z

    We report a detailed structure and defect characterization study on gallium phosphide (GaP) layers integrated on silicon (Si) (001) via silicon-germanium (SiGe) buffer layers. The presented approach uses an almost fully relaxed SiGe buffer heterostructure of only 400?nm thickness whose in-plane lattice constant is matched to GaP—not at room but at GaP deposition temperature. Single crystalline, pseudomorphic 270?nm thick GaP is successfully grown by metalorganic chemical vapour deposition on a 400?nm Si{sub 0.85}Ge{sub 0.15}/Si(001) heterosystem, but carries a 0.08% tensile strain after cooling down to room temperature due to the bigger thermal expansion coefficient of GaP with respect to Si. Transmission electron microscopy (TEM) studies confirm the absence of misfit dislocations in the pseudomorphic GaP film but growth defects (e.g., stacking faults, microtwins, etc.) especially at the GaP/SiGe interface region are detected. We interpret these growth defects as a residue of the initial 3D island coalescence phase of the GaP film on the SiGe buffer. TEM-energy-dispersive x-ray spectroscopy studies reveal that these defects are often correlated with stoichiometric inhomogeneities in the GaP film. Time-of-flight Secondary ion mass spectrometry detects sharp heterointerfaces between GaP and SiGe films with a minor level of Ga diffusion into the SiGe buffer.

  17. Green light emission by InGaN/GaN multiple-quantum-well microdisks

    SciTech Connect (OSTI)

    Hsu, Yu-Chi; Lo, Ikai, E-mail: ikailo@mail.phys.nsysu.edu.tw; Shih, Cheng-Hung; Pang, Wen-Yuan; Hu, Chia-Hsuan; Wang, Ying-Chieh; Tsai, Cheng-Da; Chou, Mitch M. C. [Department of Physics, Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China)] [Department of Physics, Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Hsu, Gary Z. L. [United Crystal Corporation, No. 243-3, Wenshan 36061, Miaoli, Taiwan (China)] [United Crystal Corporation, No. 243-3, Wenshan 36061, Miaoli, Taiwan (China)

    2014-03-10T23:59:59.000Z

    The high-quality In{sub x}Ga{sub 1?x}N/GaN multiple quantum wells were grown on GaN microdisks with ?-LiAlO{sub 2} substrate by using low-temperature two-step technique of plasma-assisted molecular beam epitaxy. We demonstrated that the hexagonal GaN microdisk can be used as a strain-free substrate to grow the advanced In{sub x}Ga{sub 1?x}N/GaN quantum wells for the optoelectronic applications. We showed that the green light of 566-nm wavelength (2.192?eV) emitted from the In{sub x}Ga{sub 1?x}N/GaN quantum wells was tremendously enhanced in an order of amplitude higher than the UV light of 367-nm wavelength (3.383?eV) from GaN.

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

    DOE Patents [OSTI]

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

    2001-01-01T23:59:59.000Z

    An InGaAsN/GaAs semiconductor p-n heterojunction is disclosed for use in forming a 0.95-1.2 eV bandgap photodetector with application for use in high-efficiency multi-junction solar cells. The InGaAsN/GaAs p-n heterojunction is formed by epitaxially growing on a gallium arsenide (GaAs) or germanium (Ge) substrate an n-type indium gallium arsenide nitride (InGaAsN) layer having a semiconductor alloy composition In.sub.x Ga.sub.1-x As.sub.1-y N.sub.y with 0GaAs layer, with the InGaAsN and GaAs layers being lattice-matched to the substrate. The InGaAsN/GaAs p-n heterojunction can be epitaxially grown by either molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD). The InGaAsN/GaAs p-n heterojunction provides a high open-circuit voltage of up to 0.62 volts and an internal quantum efficiency of >70%.

  19. Controls of Magnetic Islands by Pellet Injection in Tokamaks

    SciTech Connect (OSTI)

    Shaing, K. C. [University of Wisconsin; Houlberg, Wayne A [ORNL; Peng, Yueng Kay Martin [ORNL

    2007-01-01T23:59:59.000Z

    The appearance of magnetic islands in tokamaks degrades plasma confinement. It is therefore important to control or eliminate the growth of the islands to improve the performance of a tokamak. A theory is developed to control magnetic islands using the localized pressure gradient driven bootstrap current by injecting pellets at the O-point of the island to create a peaked plasma pressure profile inside the island. This localized bootstrap current replenishes the missing equilibrium bootstrap current density that causes the island to grow in the first place. It is shown that the effect of the localized bootstrap current tends to reduce or eliminate the original drive for the growth of the island in the island evolution equation. The theory is also valid for the localized bootstrap current created by localized heating, but with much less effectiveness. A possibility of eliminating the island by controlling the equilibrium profiles is also discussed.

  20. Control of magnetic islands by pellet injection in tokamaks

    SciTech Connect (OSTI)

    Shaing, K. C. [University of Wisconsin; Rome, James A [ORNL; Peng, Yueng Kay Martin [ORNL

    2007-01-01T23:59:59.000Z

    The appearance of magnetic islands in tokamaks degrades plasma confinement. It is therefore important to control or eliminate the growth of the islands to improve the performance of a tokamak. A theory is developed to control magnetic islands using the localized pressure gradient driven bootstrap current by injecting pellets at the O-point of the island to create a peaked plasma pressure profile inside the island. This localized bootstrap current replenishes the missing equilibrium bootstrap current density that causes the island to grow in the first place. It is shown that the effect of the localized bootstrap current tends to reduce or eliminate the original drive for the growth of the island in the island evolution equation. The theory is also valid for the localized bootstrap current created by localized heating, but with much less effectiveness. A possibility of eliminating the island by controlling the equilibrium profiles is also discussed. (c) 2007 American Institute of Physics.

  1. Control of magnetic islands by pellet injection in tokamaks

    SciTech Connect (OSTI)

    Shaing, K. C.; Houlberg, W. A.; Peng, M. [Engineering Physics Department, University of Wisconsin, Madison, Wisconsin 53706 (United States); Fusion Energy Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2007-07-15T23:59:59.000Z

    The appearance of magnetic islands in tokamaks degrades plasma confinement. It is therefore important to control or eliminate the growth of the islands to improve the performance of a tokamak. A theory is developed to control magnetic islands using the localized pressure gradient driven bootstrap current by injecting pellets at the O-point of the island to create a peaked plasma pressure profile inside the island. This localized bootstrap current replenishes the missing equilibrium bootstrap current density that causes the island to grow in the first place. It is shown that the effect of the localized bootstrap current tends to reduce or eliminate the original drive for the growth of the island in the island evolution equation. The theory is also valid for the localized bootstrap current created by localized heating, but with much less effectiveness. A possibility of eliminating the island by controlling the equilibrium profiles is also discussed.

  2. InGaP/GaAs and InGaAs mechanically-stacked triple-junction solar cells

    SciTech Connect (OSTI)

    Takamoto, T.; Ikeda, E.; Agui, T. [Japan Energy Corp., Toda, Saitama (Japan)] [and others

    1997-12-31T23:59:59.000Z

    Triple-junction cells with AM1.5 efficiencies of over 33% have been demonstrated. A planar type InGaP/GaAs monolithic dual-junction cell was fabricated on a semi-insulating FaAs substrate, which has high infra-red transparency. Then a dual-junction cell, with efficiency of 27--28%, was mechanically stacked on an InGaAs cell fabricated on an InP substrate. The bottom InGaAs cell showed an efficiency of 6.2% under the InGaP/GaAs cell, and a total efficiency of 33--34% was achieved for the four-terminal triple-junction cell.

  3. Graphene induced remote surface scattering in graphene/AlGaN/GaN heterostructures

    SciTech Connect (OSTI)

    Liu, Xiwen; Li, Dan; Wang, Bobo; Liu, Bin; Chen, Famin; Jin, Guangri; Lu, Yanwu, E-mail: ywlu@bjtu.edu.cn [Department of Physics, Beijing Jiaotong University, Beijing 100044 (China)

    2014-10-20T23:59:59.000Z

    The mobilities of single-layer graphene combined with AlGaN/GaN heterostructures on two-dimensional electron gases in graphene/AlGaN/GaN double heterojunction are calculated. The impact of electron density in single-layer graphene is also studied. Remote surface roughness (RSR) and remote interfacial charge (RIC) scatterings are introduced into this heterostructure. The mobilities limited by RSR and RIC are an order of magnitude higher than that of interface roughness and misfit dislocation. This study contributes to designing structures for generation of higher electron mobility in graphene/AlGaN/GaN double heterojunction.

  4. Experimental evidence of Ga-vacancy induced room temperature ferromagnetic behavior in GaN films

    SciTech Connect (OSTI)

    Roul, Basanta; Kumar, Mahesh [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Central Research Laboratory, Bharat Electronics, Bangalore 560013 (India); Rajpalke, Mohana K.; Bhat, Thirumaleshwara N.; Krupanidhi, S. B. [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Kalghatgi, A. T. [Central Research Laboratory, Bharat Electronics, Bangalore 560013 (India); Kumar, Nitesh; Sundaresan, A. [Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064 (India)

    2011-10-17T23:59:59.000Z

    We have grown Ga deficient GaN epitaxial films on (0001) sapphire substrate by plasma-assisted molecular beam epitaxy and report the experimental evidence of room temperature ferromagnetic behavior. The observed yellow emission peak in room temperature photoluminescence spectra and the peak positioning at 300 cm{sup -1} in Raman spectra confirms the existence of Ga vacancies. The x-ray photoelectron spectroscopic measurements further confirmed the formation of Ga vacancies; since the N/Ga is found to be >1. The ferromagnetism is believed to originate from the polarization of the unpaired 2p electrons of N surrounding the Ga vacancy.

  5. Ultra-Thin, Triple-Bandgap GaInP/GaAs/GaInAs Monolithic Tandem Solar Cells

    SciTech Connect (OSTI)

    Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

    2007-02-01T23:59:59.000Z

    The performance of state-of-the-art, series-connected, lattice-matched (LM), triple-junction (TJ), III-V tandem solar cells could be improved substantially (10-12%) by replacing the Ge bottom subcell with a subcell having a bandgap of {approx}1 eV. For the last several years, research has been conducted by a number of organizations to develop {approx}1-eV, LM GaInAsN to provide such a subcell, but, so far, the approach has proven unsuccessful. Thus, the need for a high-performance, monolithically integrable, 1-eV subcell for TJ tandems has remained. In this paper, we present a new TJ tandem cell design that addresses the above-mentioned problem. Our approach involves inverted epitaxial growth to allow the monolithic integration of a lattice-mismatched (LMM) {approx}1-eV GaInAs/GaInP double-heterostructure (DH) bottom subcell with LM GaAs (middle) and GaInP (top) upper subcells. A transparent GaInP compositionally graded layer facilitates the integration of the LM and LMM components. Handle-mounted, ultra-thin device fabrication is a natural consequence of the inverted-structure approach, which results in a number of advantages, including robustness, potential low cost, improved thermal management, incorporation of back-surface reflectors, and possible reclamation/reuse of the parent crystalline substrate for further cost reduction. Our initial work has concerned GaInP/GaAs/GaInAs tandem cells grown on GaAs substrates. In this case, the 1-eV GaInAs experiences 2.2% compressive LMM with respect to the substrate. Specially designed GaInP graded layers are used to produce 1-eV subcells with performance parameters nearly equaling those of LM devices with the same bandgap (e.g., LM, 1-eV GaInAsP grown on InP). Previously, we reported preliminary ultra-thin tandem devices (0.237 cm{sup 2}) with NREL-confirmed efficiencies of 31.3% (global spectrum, one sun) (1), 29.7% (AM0 spectrum, one sun) (2), and 37.9% (low-AOD direct spectrum, 10.1 suns) (3), all at 25 C. Here, we include recent results of testing similar devices under the concentrated AMO spectrum, and also present the first demonstration of a high-efficiency, ultra-thin GaInP/GaAs/GaInAs tandem cell processed on a flexible kapton handle.

  6. September 16-21, 2007 Las Vegas, Nevada Gate recess technology on AlGaN/GaN HFET with InGaN as etch-stop layer

    E-Print Network [OSTI]

    Pala, Nezih

    0 2 V(V) C(pF) Before etching (material) After etching (device) G AlGaN substrate i-GaN DS AlN AlGaN substrate AlN i-GaN AlGaN S G DAlGaNAlGaN InGaNInGaN Standard gate recess InGaN stop layer gate recess InGaNICNS 7 September 16-21, 2007 ­ Las Vegas, Nevada Gate recess technology on AlGaN/GaN HFET with InGaN

  7. Rutile films grown by molecular beam epitaxy on GaN and AlGaN/GaN P. J. Hansen

    E-Print Network [OSTI]

    York, Robert A.

    Rutile films grown by molecular beam epitaxy on GaN and AlGaN/GaN P. J. Hansen Materials Department March 2005 Titanium dioxide TiO2, with the rutile structure was grown on 0001 oriented GaN and 0001 Al0.33Ga0.67N/GaN heterostructure field effect transistor HFET structures by molecular beam epitaxy. X

  8. Single-Wire Light-Emitting Diodes Based on GaN Wires Containing Both Polar and Nonpolar InGaN/GaN Quantum Wells

    E-Print Network [OSTI]

    Single-Wire Light-Emitting Diodes Based on GaN Wires Containing Both Polar and Nonpolar InGaN/GaN based on radial p­i­n multi quantum well (QW) junctions have been realized from GaN wires grown by catalyst- free metal organic vapor phase epitaxy. The Inx Ga1Àx N/GaN undoped QW system is coated over both

  9. High density plasma damage in InGaP/GaAs as AlGaAs/GaAs high electron mobility transistors

    SciTech Connect (OSTI)

    Lee, J.W.; Pearton, S.J. [Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering; Ren, F.; Kopf, R.F.; Kuo, J.M. [Bell Labs., Murray Hill, NJ (United States). Lucent Technologies; Shul, R.J. [Sandia National Labs., Albuquerque, NM (United States); Constantine, C.; Johnson, D. [Plasma-Therm Inc., St. Petersburg, FL (United States)

    1998-11-01T23:59:59.000Z

    The introduction of plasma damage in InGaP/GaAs and AlGaAs/GaAs high electron mobility transistors (HEMTs) has been investigated using both inductively coupled plasma and electron cyclotron resonance Ar discharges. The saturated drain-source current is found to be decreased through introduction of compensating deep levels into the InGaP or AlGaAs donor layer. The degradation of device performance is a strong function of ion energy and ion flux, and an advantage of both high density plasma tools is that ion energy can be reduced by increasing the plasma density. Increasing process pressure and source power, and decreasing radio-frequency chuck power produce the lowest amounts of plasma damage in HEMTs.

  10. Comparison of compressive and tensile relaxed composition-graded GaAsP and ,,Al...InGaP substrates

    E-Print Network [OSTI]

    Comparison of compressive and tensile relaxed composition-graded GaAsP and ,,Al...InGaP substrates, around 104 cm-2 . The structures, grown on GaP or GaAs, consist of graded In-fraction InGaP and AlInGaP. High surface roughness and branch defects in Al InGaP lead to the lowest quality virtual substrates we

  11. Carrier Dynamics in InGaN/GaN SQW Structure Probed by the Transient Grating Method

    E-Print Network [OSTI]

    Okamoto, Koichi

    Carrier Dynamics in InGaN/GaN SQW Structure Probed by the Transient Grating Method; 78.55.Cr; 78.67.De; S7.14 Carrier dynamics in GaN and InGaN/GaN SQW structures were observed by using inhomogeneity of In composition. Recently, InGaN/GaN-based light emitting diodes (LEDs) have been commercialized

  12. N-Face GaN/AlGaN HEMTs Fabricated Through Layer Transfer Technology

    E-Print Network [OSTI]

    Chung, Jinwook

    We present a new method to fabricate N-face GaN/AlGaN high electron mobility transistors (HEMTs). These devices are extremely promising for ultrahigh frequency applications where low contact resistances and excellent carrier ...

  13. Development and Industrialization of InGaN/GaN LEDs on Patterned...

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

    of InGaNGaN LEDs on Patterned Sapphire Substrates for Low Cost Emitter Architecture Development and Industrialization of InGaNGaN LEDs on Patterned Sapphire...

  14. Breakdown mechanism in AlGaN/GaN HEMTs on Si substrate

    E-Print Network [OSTI]

    Lu, Bin

    AlGaN/GaN high electron mobility transistors (HEMTs) grown on Si substrates have attracted a great interest for power electronics applications. Despite the low cost of the Si substrate, the breakdown voltage (V[subscript ...

  15. U.S. Navy - San Clemente Island, California | Department of Energy

    Energy Savers [EERE]

    San Clemente Island, California U.S. Navy - San Clemente Island, California Photo of Wind Turbine on San Clemente Island, California San Clemente Island is one of the Channel...

  16. Siemens Pittsburgh, PA Novelis Corporation Atlanta, GA

    E-Print Network [OSTI]

    McGaughey, Alan

    Industrial Design ­ Shanghai, China Eaton Corporation ­ Pittsburgh, PA CMU, CTTEC ­ PittsburghSiemens ­ Pittsburgh, PA Novelis Corporation ­ Atlanta, GA Expense

  17. Strain-balanced InGaN/GaN multiple quantum wells

    SciTech Connect (OSTI)

    Van Den Broeck, D. M.; Hosalli, A. M.; Bedair, S. M. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Bharrat, D.; El-Masry, N. A. [Department of Material Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-07-21T23:59:59.000Z

    InGaN/GaN multiple quantum well (MQW) structures suffer from a high amount of compressive strain in the InGaN wells and the accompanied piezoelectric field resulting in both a blue shift in emission and a reduction of emission intensity. We report the growth of In{sub x}Ga{sub 1?x}N/GaN “strain-balanced” multiple quantum wells (SBMQWs) grown on thick In{sub y}Ga{sub 1?y}N templates for x?>?y by metal organic chemical vapor deposition. SBMQWs consist of alternating layers of In{sub x}Ga{sub 1?x}N wells and GaN barriers under compressive and tensile stress, respectively, which have been lattice matched to a thick In{sub y}Ga{sub 1?y}N template. Growth of the In{sub y}Ga{sub 1?y}N template is also detailed in order to achieve thick, relaxed In{sub y}Ga{sub 1?y}N grown on GaN without the presence of V-grooves. When compared to conventional In{sub x}Ga{sub 1?x}N/GaN MQWs grown on GaN, the SBMQW structures exhibit longer wavelength emission and higher emission intensity for the same InN mole fraction due to a reduction in the well strain and piezoelectric field. By matching the average lattice constant of the MQW active region to the lattice constant of the In{sub y}Ga{sub 1?y}N template, essentially an infinite number of periods can be grown using the SBMQW growth method without relaxation-related effects. SBMQWs can be utilized to achieve longer wavelength emission in light emitting diodes without the use of excess indium and can be advantageous in addressing the “green gap.”.

  18. High current gain InGaN=GaN HBTs with C operating temperature

    E-Print Network [OSTI]

    Asbeck, Peter M.

    with an $20 nm low-temperature (Tg ¼ 550 C) GaN buffer layer on a (0001) sapphire substrate. The layer 1018 cmÀ3 Buffer GaN 2.5 mm ­ Substrate Sapphire ­ ­ HBT device processing began by depositing a 100 nmHigh current gain InGaN=GaN HBTs with 300 C operating temperature D.M. Keogh, P.M. Asbeck, T. Chung

  19. Switchable piezoelectric transduction in AlGaN/GaN MEMS resonators

    E-Print Network [OSTI]

    Weinstein, Dana

    This work presents a new switching mechanism in piezoelectric transduction of AlGaN/GaN bulk acoustic resonators. A piezoelectric transducer is formed in the AlGaN, between a top Schottky electrode and a 2D electron gas ...

  20. Spontaneous emission in GaN/InGaN photonic crystal nanopillars

    E-Print Network [OSTI]

    Boyer, Edmond

    . Sigalas, "InGaN/GaN quantum-well heterostructure light-emitting diodes employing photonic crystal, "III-nitride blue and ultraviolet photonic crystal light emitting diodes," Appl. Phys. Lett. 84, 466, and H. Benisty, "Photonic-crystal GaN light-emitting diodes with tailored guided modes distribution

  1. Geographic and Temporal Variability of Middle Holocene Red Abalone Middens on San Miguel Island, California

    E-Print Network [OSTI]

    Braje, Todd J

    2007-01-01T23:59:59.000Z

    survey of the south coast of San Miguel Island as part of Chaimel Islands National Park's cultural resource management plan (

  2. A Distributed Generation Control Architecture for Islanded AC Microgrids

    E-Print Network [OSTI]

    Dominguez-Garcia, Alejandro

    1 A Distributed Generation Control Architecture for Islanded AC Microgrids Stanton T. Cady, Student architecture for generation control in islanded microgrids, and illustrate the performance Member, IEEE Abstract In this paper, we propose a distributed architecture for generation control

  3. The UNIVERSITY OF DELAWARE The Canary Islands Health Care Systems

    E-Print Network [OSTI]

    Firestone, Jeremy

    The UNIVERSITY OF DELAWARE and the Present The Canary Islands Health Care Systems 3 week internship to the local community in the Canary Islands by teaching English to the local residents or volunteering

  4. Global isotopic signatures of oceanic island basalts / by

    E-Print Network [OSTI]

    Oschmann, Lynn A

    1991-01-01T23:59:59.000Z

    Sr, Nd and Pb isotopic analyses of 477 samples representing 30 islands or island groups, 3 seamounts or seamount chains, 2 oceanic ridges and 1 oceanic plateau [for a total of 36 geographic features] are compiled to form ...

  5. andres island school: Topics by E-print Network

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

    2 Solar School Program in Reunion Island Texas A&M University - TxSpace Summary: system efficiency. In Runion Island, the industrial engineering laboratory is involved in the...

  6. Community Economic Development Business Program (Prince Edward Island, Canada)

    Broader source: Energy.gov [DOE]

    The Community Economic Development Business (CEDB) program has been created as part of the Prince Edward Island Rural Action Plan to support local investment in innovative Prince Edward Island...

  7. Perceptions of nature in the Caribbean island of Dominica 

    E-Print Network [OSTI]

    Yarde, Therese Natalie

    2012-11-29T23:59:59.000Z

    The Commonwealth of Dominica has acquired a reputation as the nature island of the Caribbean. This thesis sets out to explore how Dominicans perceive and relate to nature in their nature island. It considers these perceptions ...

  8. GaInP/GaAs/GaInAs Monolithic Tandem Cells for High-Performance Solar Concentrators

    SciTech Connect (OSTI)

    Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

    2005-08-01T23:59:59.000Z

    We present a new approach for ultra-high-performance tandem solar cells that involves inverted epitaxial growth and ultra-thin device processing. The additional degree of freedom afforded by the inverted design allows the monolithic integration of high-, and medium-bandgap, lattice-matched (LM) subcell materials with lower-bandgap, lattice-mismatched (LMM) materials in a tandem structure through the use of transparent compositionally graded layers. The current work concerns an inverted, series-connected, triple-bandgap, GaInP (LM, 1.87 eV)/GaAs (LM, 1.42 eV)/GaInAs (LMM, {approx}1 eV) device structure grown on a GaAs substrate. Ultra-thin tandem devices are fabricated by mounting the epiwafers to pre-metallized Si wafer handles and selectively removing the parent GaAs substrate. The resulting handle-mounted, ultra-thin tandem cells have a number of important advantages, including improved performance and potential reclamation/reuse of the parent substrate for epitaxial growth. Additionally, realistic performance modeling calculations suggest that terrestrial concentrator efficiencies in the range of 40-45% are possible with this new tandem cell approach. A laboratory-scale (0.24 cm2), prototype GaInP/GaAs/GaInAs tandem cell with a terrestrial concentrator efficiency of 37.9% at a low concentration ratio (10.1 suns) is described, which surpasses the previous world efficiency record of 37.3%.

  9. Genomic islands predict functional adaptation in marine actinobacteria

    E-Print Network [OSTI]

    Penn, Kevin

    2010-01-01T23:59:59.000Z

    Ecological adaptations among bacterial populations have been linked to genomic islands, strain-specific regions of DNA that house

  10. United States Virgin Islands: St. Thomas (Bovoni) & St. Croix (Longford)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Roberts, O.; Andreas, A.

    Two measurement stations to collect wind data to support future wind power generation in the U.S. Virgin Islands.

  11. Fine structure of Fe-Co-Ga and Fe-Cr-Ga alloys with low Ga content

    SciTech Connect (OSTI)

    Kleinerman, Nadezhda M., E-mail: kleinerman@imp.uran.ru; Serikov, Vadim V., E-mail: kleinerman@imp.uran.ru; Vershinin, Aleksandr V., E-mail: kleinerman@imp.uran.ru; Mushnikov, Nikolai V., E-mail: kleinerman@imp.uran.ru; Stashkova, Liudmila A., E-mail: kleinerman@imp.uran.ru [Institute of Metal Physics UB RAS, S. Kovalevskaya str. 18, 620990 Ekaterinburg (Russian Federation)

    2014-10-27T23:59:59.000Z

    Investigation of Ga influence on the structure of Fe-Cr and Fe-Co alloys was performed with the use of {sup 57}Fe Mössbauer spectroscopy and X-ray diffraction methods. In the alloys of the Fe-Cr system, doping with Ga handicaps the decomposition of solid solutions, observed in the binary alloys, and increases its stability. In the alloys with Co, Ga also favors the uniformity of solid solutions. The analysis of Mössbauer experiments gives some grounds to conclude that if, owing to liquation, clusterization, or initial stages of phase separation, there exist regions enriched in iron, some amount of Ga atoms prefer to enter the nearest surroundings of iron atoms, thus forming binary Fe-Ga regions (or phases)

  12. TEM Characterization of InAs/GaAs Quantum Dots Capped by a GaSb/GaAs Layer

    SciTech Connect (OSTI)

    Beltran, AM [Universidad de Cadiz, Spain; Ben, Teresa [Universidad de Cadiz, Spain; Sanchez, AM [Universidad de Cadiz, Spain; Sales Lerida, David [ORNL; Chisholm, Matthew F [ORNL; Varela del Arco, Maria [ORNL; Pennycook, Stephen J [ORNL; Galindo, Pedro [Universidad de Cadiz, Spain; Ripalda, JM [Instituto de Microelectronica de Madrid (CNM, CSIC); Molina Rubio, Sergio I [ORNL

    2008-01-01T23:59:59.000Z

    It is well known that there is intense interest in expanding the usable wavelength for electronic devices. This is one of the reasons to study new self-assembled semiconductor nanostructures. Telecommunication applications use InGaAsP/InP emitting at 1.3 and 1.55 m. Research efforts are dedicated to develop GaAs technology in order to achieve emission at the same range as InP, so GaAs could be used for optical fibre communications. Ga(As)Sb on InAs/GaAs quantum dots (QDs) is a promising nanostructure to be used in telecommunications. The introduction of antimony during or after the QDs growth is an effective solution to obtain a red shift in the emission wavelength, even at room temperature.

  13. Excitonic properties of strained wurtzite and zinc-blende GaNAlxGa1xN quantum dots

    E-Print Network [OSTI]

    Fonoberov, Vladimir

    Excitonic properties of strained wurtzite and zinc-blende GaNÕAlxGa1ÀxN quantum dots Vladimir A 2003 We investigate exciton states theoretically in strained GaN/AlN quantum dots with wurtzite WZ of GaN QDs.1­8 Molecu- lar beam epitaxial growth in the Stranski­Krastanov mode of wurtzite WZ Ga

  14. Morphological and compositional variations in strain-compensated InGaAsP/InGaP superlattices

    E-Print Network [OSTI]

    Feenstra, Randall

    Morphological and compositional variations in strain- compensated InGaAsP/InGaP superlattices R of Technology, Kista, Sweden Abstract We have investigated the properties of strain-compensated InGaAsP/In- GaP superlattices, grown by metalorganic vapor phase epitaxy, with and without InP interlayers inserted in the InGaP

  15. Operating Characteristics of GaAs/InGaP Self Aligned Stripe Lasers Benjamin J. Stevens1

    E-Print Network [OSTI]

    Operating Characteristics of GaAs/InGaP Self Aligned Stripe Lasers Benjamin J. Stevens1 , Kristian of GaAs based self-aligned lasers based upon a single overgrowth. A lattice matched n-doped InGaP layer were exposed to oxygen. True buried heterostructures devices utilising InGaP clad- ding layers have

  16. Microstructure and luminescent properties of novel InGaP alloys on relaxed GaAsP substrates

    E-Print Network [OSTI]

    Microstructure and luminescent properties of novel InGaP alloys on relaxed GaAsP substrates M. J of unconventional alloys of InGaP with In fraction of 0.2­0.4 grown on fully relaxed GaAsP virtual substrates demonstrate growth of extremely high quality InGaP heterostructures which hold promise for fabrication

  17. Band Offsets of InGaP/GaAs Heterojunctions by Scanning Tunneling Spectroscopy Y. Dong and R. M. Feenstra

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Band Offsets of InGaP/GaAs Heterojunctions by Scanning Tunneling Spectroscopy Y. Dong and R. M Abstract Scanning tunneling microscopy and spectroscopy are used to study InGaP/GaAs heterojunctions computation of the tunnel current. Curve fitting of theory to experiment is performed. Using an InGaP band gap

  18. Negative capacitance in GaN/AlGaN heterojunction dual-band detectors L. E. Byrum,1

    E-Print Network [OSTI]

    Dietz, Nikolaus

    Negative capacitance in GaN/AlGaN heterojunction dual-band detectors L. E. Byrum,1 G. Ariyawansa,1 online 2 September 2009 A study of trap states in n+ -GaN/AlGaN heterostructures using electrical related absorption centers attributed to shallow Si-donor pinned to the AlGaN barrier , N-vacancy/ C

  19. High Power Wideband AlGaN/GaN HEMT Feedback Amplifier Module with Drain and Feedback Loop

    E-Print Network [OSTI]

    Itoh, Tatsuo

    High Power Wideband AlGaN/GaN HEMT Feedback Amplifier Module with Drain and Feedback Loop amplifier module using AlGaN/GaN high electron mobility transistor (HEMT) has been developed that covers radars and communications systems. GaN-based HEMT's for high power applications at microwave frequencies

  20. New constraints on the Slate Islands impact structure, Ontario, Canada

    E-Print Network [OSTI]

    Herrick, Robert R.

    New constraints on the Slate Islands impact structure, Ontario, Canada Virgil L. Sharpton Lunar, Canada John Scott ABSTRACT The Slate Islands in northern Lake Superior represent the eroded remains constrained. INTRODUCTION The Slate Islands are an 7-km-wide archipelago located in northern Lake Superior 10

  1. Stomach contents of cetaceans stranded in the Canary Islands 19962006

    E-Print Network [OSTI]

    Pierce, Graham

    Stomach contents of cetaceans stranded in the Canary Islands 1996­2006 r. fernandez1 , m.b. santos2, Kogiidae and Ziphiidae, stranded between 1996 and 2006 in the Canary Islands. Cephalopod mandibles (beaks teuthophagous whales. Keywords: feeding, Canary Islands, cetaceans, cephalopods, plastic Submitted 5 August 2008

  2. ORIGINAL PAPER Bird pollination of Canary Island endemic plants

    E-Print Network [OSTI]

    Northampton, University of

    ORIGINAL PAPER Bird pollination of Canary Island endemic plants Jeff Ollerton & Louise Cranmer /Accepted: 29 September 2008 # Springer-Verlag 2008 Abstract The Canary Islands are home to a guild Bird vision . Canary Islands . Mutualism . Pollinator. Tenerife Introduction The endemic flora

  3. ORIGINAL PAPER Bird pollination of Canary Island endemic plants

    E-Print Network [OSTI]

    Chittka, Lars

    ORIGINAL PAPER Bird pollination of Canary Island endemic plants Jeff Ollerton & Louise Cranmer) was an effective pollinator of these species. Keywords Bird vision . Canary Islands . Mutualism . Pollinator. Tenerife Introduction The endemic flora of the Canary Islands, situated off the west coast of North Africa

  4. SysBioMed Canary Islands Cancer Research

    E-Print Network [OSTI]

    Timmer, Jens

    SysBioMed Canary Islands Cancer Research Institute Winter School on Systems Biology for Medical Applications 27th February ­ 2nd March 2007 Puerto de la Cruz, Tenerife (Canary Islands) Supported by the European Commission (FP6 projects COSBICS and SysBioMed) and the Canary Islands Institute for Cancer

  5. The Urban Heat Island: Linking Science, Society, and Technology

    E-Print Network [OSTI]

    Hall, Sharon J.

    The Urban Heat Island: Linking Science, Society, and Technology Living in the desert has always much heat. As Phoenix has grown, the natural environment has been transformed from native desert: · Investigate the Urban Heat Island phenomenon · Explore the impact of the Urban Heat Island on people and other

  6. Data Update for Thompson Island, Boston Harbor, MA August 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA August 2008 Prepared for Massachusetts 2008 This update summarizes the monthly data results for the Thompson Island monitoring site in Boston this maintenance. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island for the month

  7. Data Update for Thompson Island, Boston Harbor, MA January 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA January 2008 Prepared for Massachusetts for January 2008 This update summarizes the monthly data results for the Thompson Island monitoring site is a graph of wind speed at Thompson Island for the month of January 2008, at the highest anemometer height

  8. Data Update for Thompson Island, Boston Harbor, MA February 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA February 2007 Prepared for Massachusetts for February 2007 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of February 2007, at the highest anemometer height of 40 m. #12;

  9. Data Update for Thompson Island, Boston Harbor, MA October 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA October 2007 Prepared for Massachusetts for October 2007 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of October 2007, at the highest anemometer height of 40 m. #12;

  10. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA July 2006 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA the next service visit. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  11. Data Update for Thompson Island, Boston Harbor, MA November 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA November 2008 Prepared for Massachusetts for November 2008 This update summarizes the monthly data results for the Thompson Island monitoring site is a graph of wind speed at Thompson Island for the month of November 2008, at the highest anemometer height

  12. Data Update for Thompson Island, Boston Harbor, MA November 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA November 2006 Prepared for Massachusetts for November 2006 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of November 2006, at the highest anemometer height of 40 m

  13. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA March 2007 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA speed at Thompson Island for the month of March 2007, at the highest anemometer height of 40 m. #12;

  14. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA May 2008 Prepared for Massachusetts Technology summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA, at 42° 18 below is a graph of wind speed at Thompson Island for the month of May 2008, at the highest anemometer

  15. Data Update for Thompson Island, Boston Harbor, MA November 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA November 2007 Prepared for Massachusetts for November 2007 This update summarizes the monthly data results for the Thompson Island monitoring site Data Time Series Seen below is a graph of wind speed at Thompson Island for the month of November 2007

  16. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA May 2006 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA the next site visit. · Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  17. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA March 2006 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA the spring of 2006. · Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  18. Data Update for Thompson Island, Boston Harbor, MA December 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA December 2007 Prepared for Massachusetts for December 2007 This update summarizes the monthly data results for the Thompson Island monitoring site. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island for the month of December

  19. Data Update for Thompson Island, Boston Harbor, MA January 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA January 2007 Prepared for Massachusetts for January 2007 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of January 2007, at the highest anemometer height of 40 m. #12;

  20. Data Update for Thompson Island, Boston Harbor, MA December 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA December 2008 Prepared for Massachusetts for December 2008 This update summarizes the monthly data results for the Thompson Island monitoring site is a graph of wind speed at Thompson Island for the month of December 2008, at the highest anemometer height

  1. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA July 2007 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA speed at Thompson Island for the month of July 2007, at the highest anemometer height of 40 m. #12;

  2. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA June 2008 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA to the sensor cables. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  3. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA April 2007 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA speed at Thompson Island for the month of April 2007, at the highest anemometer height of 40 m. #12;

  4. Data Update for Thompson Island, Boston Harbor, MA October 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA October 2006 Prepared for Massachusetts for October 2006 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of October 2006, at the highest anemometer height of 40 m

  5. Data Update for Thompson Island, Boston Harbor, MA September 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA September 2006 Prepared for Massachusetts for September 2006 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of September 2006, at the highest anemometer height of 40 m

  6. Data Update for Thompson Island, Boston Harbor, MA August 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA August 2006 Prepared for Massachusetts for August 2006 This update summarizes the monthly data results for the Thompson Island monitoring site Seen below is a graph of wind speed at Thompson Island for the month of August 2006, at the highest

  7. Data Update for Thompson Island, Boston Harbor, MA September 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA September 2007 Prepared for Massachusetts for September 2007 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of September 2007, at the highest anemometer height of 40 m. #12;

  8. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA June 2006 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA the next service visit. · Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  9. Data Update for Thompson Island, Boston Harbor, MA February 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA February 2006 Prepared for Massachusetts for February 2006 This update summarizes the monthly data results for the Thompson Island monitoring site of 2006. · Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island for the month

  10. Data Update for Thompson Island, Boston Harbor, MA October 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA October 2008 Prepared for Massachusetts for October 2008 This update summarizes the monthly data results for the Thompson Island monitoring site issues arose this month. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  11. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA April 2006 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA the next service visit. · Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  12. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA June 2007 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA speed at Thompson Island for the month of June 2007, at the highest anemometer height of 40 m. #12;

  13. Data Update for Thompson Island, Boston Harbor, MA August 2007

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA August 2007 Prepared for Massachusetts 2007 This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Time Series Seen below is a graph of wind speed at Thompson Island for the month of August 2007

  14. Data Update for Thompson Island, Boston Harbor, MA September 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA September 2008 Prepared for Massachusetts for September 2008 This update summarizes the monthly data results for the Thompson Island monitoring site issues arose this month. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  15. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA March 2008 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA is a graph of wind speed at Thompson Island for the month of March 2008, at the highest anemometer height

  16. Data Update for Thompson Island, Boston Harbor, MA December 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA December 2006 Prepared for Massachusetts for December 2006 This update summarizes the monthly data results for the Thompson Island monitoring site speed at Thompson Island for the month of December 2006, at the highest anemometer height of 40 m

  17. Data Update for Thompson Island, Boston Harbor, MA January 2006

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA January 2006 Prepared for Massachusetts for January 2006 This update summarizes the monthly data results for the Thompson Island monitoring site. · Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island for the month of January

  18. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA July 2008 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA to the sensor cables. Monthly Data Time Series Seen below is a graph of wind speed at Thompson Island

  19. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA May 2007 Prepared for Massachusetts Technology summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA, at 42° 18 speed at Thompson Island for the month of May 2007, at the highest anemometer height of 40 m. #12;

  20. Data Update for Thompson Island, Boston Harbor, MA February 2008

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA February 2008 Prepared for Massachusetts for February 2008 This update summarizes the monthly data results for the Thompson Island monitoring site is a graph of wind speed at Thompson Island for the month of February 2008, at the highest anemometer height

  1. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA July 2005 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA Series #12;Seen below is a graph of wind speed at Thompson Island for the month of July 2005

  2. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    and the islands' geology. Rain water harvesting is required by law and serves as the principal water sourceVirgin Islands Water Resources Research Institute Annual Technical Report FY 2009 Virgin Islands Water Resources Research Institute Annual Technical Report FY 2009 1 #12;Introduction The U. S. Virgin

  3. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    always been a major concern in these small volcanic islands where rain water harvesting, ground waterVirgin Islands Water Resources Research Institute Annual Technical Report FY 2007 Virgin Islands Water Resources Research Institute Annual Technical Report FY 2007 1 #12;Introduction The United States

  4. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    areas. In the U. S. Virgin Islands rain water harvesting and seawater desalination are the principalVirgin Islands Water Resources Research Institute Annual Technical Report FY 2005 Introduction The Virgin Islands Water Resources Research Institute (VI-WRRI) is located at the University of the Virgin

  5. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    water harvesting are the principal sources of fresh water. Ground water supplies are very limited. WaterVirgin Islands Water Resources Research Institute Annual Technical Report FY 2008 Virgin Islands Water Resources Research Institute Annual Technical Report FY 2008 1 #12;Introduction The Virgin Islands

  6. Marine Iguanas Older Than Their Islands Jeff Mitton

    E-Print Network [OSTI]

    Mitton, Jeffry B.

    Marine Iguanas Older Than Their Islands Jeff Mitton Natural Selections (Appeared in the Boulder Camera, December 11, 2009) The Galapagos Islands ride on the Nazca plate, a tectonic plate drifting toward Ecuador at the rate of one and a half inches per year. But the Galapagos Islands will never reach

  7. Impact ionization in N-polar AlGaN/GaN high electron mobility transistors

    SciTech Connect (OSTI)

    Killat, N., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk; Uren, M. J.; Kuball, M., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk [Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Keller, S.; Kolluri, S.; Mishra, U. K. [Department of Electrical and Computer Engineering, University of Santa Barbara California, Santa Barbara, California 93106 (United States)

    2014-08-11T23:59:59.000Z

    The existence of impact ionization as one of the open questions for GaN device reliability was studied in N-polar AlGaN/GaN high electron mobility transistors. Electroluminescence (EL) imaging and spectroscopy from underneath the device gate contact revealed the presence of hot electrons in excess of the GaN bandgap energy even at moderate on-state bias conditions, enabling impact ionization with hole currents up to several hundreds of pA/mm. The detection of high energy luminescence from hot electrons demonstrates that EL analysis is a highly sensitive tool to study degradation mechanisms in GaN devices.

  8. Michael J. Poston Atlanta, GA 30307

    E-Print Network [OSTI]

    Orlando, Thomas

    Page | 1 Michael J. Poston Atlanta, GA 30307 Michael.Poston@gatech.edu Cell: 770.561.4756 U.S. Citizen Education PhD Candidate in Chemistry Georgia Institute of Technology, Atlanta, GA August 2007 with Application to Lunar Observations," JGR ­ Planets, 118, 105, doi: 10.1002/jgre.20025. Poston, M. J

  9. Tunable two-dimensional plasmon resonances in an InGaAs/InP high electron mobility transistor

    E-Print Network [OSTI]

    Peale, Robert E.

    of materials systems such as GaAs/AlGaAs,3 InGaP/InGaAs/GaAs,4 GaN/AlGaN,2,5 and Si Ref. 1 have been explored

  10. FUPWG Meeting Agenda - Atlanta, GA | Department of Energy

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

    Atlanta, GA FUPWG Meeting Agenda - Atlanta, GA Energy on My Mind FUPWG Atlanta, GA May 3-4, 2006 Hosted by: AGL Resources Logo May 3-4, 2006 Hosted by AGL Resources Atlanta,...

  11. Energy Transition Initiative: Islands Playbook (Book)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01T23:59:59.000Z

    The Island Energy Playbook (the Playbook) provides an action-oriented guide to successfully initiating, planning, and completing a transition to an energy system that primarily relies on local resources to eliminate a dependence on one or two imported fuels. It is intended to serve as a readily available framework that any community can adapt to organize its own energy transition effort.

  12. AlGaN/GaN heterostructure prepared on a Si (110) substrate via pulsed sputtering

    SciTech Connect (OSTI)

    Watanabe, T.; Ohta, J.; Kondo, T.; Ohashi, M.; Ueno, K.; Kobayashi, A. [Institute of Industrial Science (IIS), The University of Tokyo, 4-6-1 Komaba, Tokyo 153-8505 (Japan); Fujioka, H., E-mail: hfujioka@iis.u-tokyo.ac.jp [Institute of Industrial Science (IIS), The University of Tokyo, 4-6-1 Komaba, Tokyo 153-8505 (Japan); CREST, Japan Science and Technology Corporation (JST), 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan)

    2014-05-05T23:59:59.000Z

    GaN films were grown on Si (110) substrates using a low-temperature growth technique based on pulsed sputtering. Reduction of the growth temperature suppressed the strain in the GaN films, leading to an increase in the critical thickness for crack formation. In addition, an AlGaN/GaN heterostructure with a flat heterointerface was prepared using this technique. Furthermore, the existence of a two dimensional electron gas at the heterointerface with a mobility of 1360 cm{sup 2}/Vs and a sheet carrier density of 1.3?×?10{sup 13}?cm{sup ?2} was confirmed. Finally, the use of the AlGaN/GaN heterostructure in a high electron mobility transistor was demonstrated. These results indicate that low-temperature growth via pulsed sputtering is quite promising for the fabrication of GaN-based electronic devices.

  13. 56 IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 1, JANUARY 2012 Metamorphic GaAsP and InGaP Solar Cells on GaAs

    E-Print Network [OSTI]

    Haller, Gary L.

    56 IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 1, JANUARY 2012 Metamorphic GaAsP and InGaP Solar bandgap range. Index Terms--Epitaxy, GaAsP, InGaP, metamorphic. I. INTRODUCTION TODAY'S highest efficiency

  14. Storage conditions and eruptive dynamics of central versus flank eruptions in volcanic islands: the case of Tenerife (Canary Islands,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : the case of Tenerife (Canary Islands, Spain) Joan Andújara,* , Fidel Costab , Bruno Scailleta a. Université1 Storage conditions and eruptive dynamics of central versus flank eruptions in volcanic islands eruptions (ca. 1 km3 ) of the Teide-Pico Viejo complex (Tenerife Island). Combined with previous

  15. Within-island differentiation and between-island homogeneity: non-equilibrium population structure in the seaweed

    E-Print Network [OSTI]

    in the seaweed Cladophoropsis membranacea (Chlorophyta) in the Canary Islands HAN J. VAN DER STRATE1, 2 , LOUIS stone model at larger spatial scales. In the present survey, 23 sites were sampled in the Canary Islands among the Canary Islands regardless of how geographic distances were computed. Only when the Canary

  16. US Army Corps of Engineers Caribbean Islands Region Version 2.0 WETLAND DETERMINATION DATA FORM Caribbean Islands Region

    E-Print Network [OSTI]

    US Army Corps of Engineers

    US Army Corps of Engineers Caribbean Islands Region ­ Version 2.0 WETLAND DETERMINATION DATA FORM ­ Caribbean Islands Region Project/Site: Municipality/Town: Sampling Date: Applicant/Owner: PR or USVI or problematic. Hydrophytic Vegetation Present? Yes No Remarks: #12;US Army Corps of Engineers Caribbean Islands

  17. Defect structures in rapidly degraded InGaAsP/InGaP double-heterostructure lasers

    SciTech Connect (OSTI)

    Ueda, O.; Wakao, K.; Yamaguchi, A.; Isozumi, S.; Komiya, S.

    1985-03-01T23:59:59.000Z

    Rapidly degraded InGaAsP/InGaP double-heterostructure lasers grown on (001)-oriented GaAs substrates by liquid phase epitaxy have been investigated by photolumi

  18. Emission properties of heterostructures with a (GaAsSb-InGaAs)/GaAs bilayer quantum well

    SciTech Connect (OSTI)

    Zvonkov, B. N.; Nekorkin, S. M.; Vikhrova, O. V.; Dikareva, N. V., E-mail: dikareva@nifti.unn.ru [Nizhni Novgorod State University, Physical-Technical Research Institute (Russian Federation)

    2013-09-15T23:59:59.000Z

    The specific features of the emission characteristics of GaAs-based heterostructures with a GaAs{sub 1-x}Sb{sub x}-In{sub y}Ga{sub 1-y}As bilayer quantum well are studied. The heterostructures are grown by metal-organic chemical vapor deposition (MOCVD). With an analysis of previously reported data on the MOCVD growth process taken into account, the temperature range (560-580 Degree-Sign C), the relation between the fluxes emitted by the sources of Group-V and -III elements ( Less-Than-Or-Equivalent-To 1), and the order of layer growth for the production of the active region of a GaAs/InGaP laser heterostructure are determined experimentally. The active region is a GaAs{sub 0.75}Sb{sub 0.25}-In{sub 0.2}Ga{sub 0.8}As bilayer quantum well. For the structure, a 1075-nm electroluminescence signal attributed to indirect transitions between the valence band of the GaAs{sub 0.75}Sb{sub 0.25} layer and the conduction band of the In{sub 0.2}Ga{sub 0.8}As layer is observed. An increase in the continuous-wave pump current yields a decrease in the 1075-nm emission intensity and initiates stable lasing at a wavelength of 1022 nm at a threshold current density of 1.4 kA cm{sup -2} at room temperature. Lasing occurs at transitions direct in coordinate space.

  19. AlGaN/GaN HFET Single-Ended Frequency Doubler Younkyu Chung and Tatsuo Itoh

    E-Print Network [OSTI]

    Itoh, Tatsuo

    AlGaN/GaN HFET Single-Ended Frequency Doubler Younkyu Chung and Tatsuo Itoh Department-mail: ykchung@ee.ucla.edu Abstract - This paper presents the first single-ended AlGaN/GaN heterojunction field, respectively. For the frequency doubler with 1mm gate periphery AlGaN/GaN HFET, conversion gain of 0.17 d

  20. Materials Science and Engineering B59 (1999) 319322 Microcalorimetric absorption spectroscopy in GaNAlGaN

    E-Print Network [OSTI]

    Nabben, Reinhard

    1999-01-01T23:59:59.000Z

    Microcalorimetric measurements of small absorption coefficients have been performed on thin GaN­AlGaN quantum wells in GaN­AlGaN quantum wells Axel Go¨ldner a, *, Axel Hoffmann a , Bernard Gil b , Pierre Lefebvre b at the energy of the GaN buffer and at the energy of the thick AlGaN barrier layers, we could also readily

  1. Al fraction induced effects on the capacitance characteristics -GaN/AlxGa1-xN IR detectors

    E-Print Network [OSTI]

    Dietz, Nikolaus

    substrate. As shown in Fig. 1(a), the device structures consist of a 0.2 m n+ -GaN top contact (emitter.1117/12.828156 Proc. of SPIE Vol. 7467 74670W-1 #12;(a) Sapphire Substrate n GaN Bottom Contact AlxGa1-xN Barrier n GaNAl fraction induced effects on the capacitance characteristics of n+ -GaN/AlxGa1-xN IR detectors

  2. Improvement of breakdown voltage in InGaP/InGaAs/GaAs heterostructure MESFETs for MMICs

    SciTech Connect (OSTI)

    Koh, Inoue; Yamane, Yasuro; Shiojima, Kenji [NTT LSI Lab., Kanagawa (Japan)] [and others

    1995-12-31T23:59:59.000Z

    This paper describes the trade-off between breakdown voltage and RF performance of InGaP/InGaAs/GaAs heterostructure MESFETs for power amplifiers and oscillators in multi-function MMICs in the millimeter-wave range. The authors successfully improved both gate-drain and drain-source breakdown voltages while maintaining excellent high-frequency performance by using a double-layered gate consisting of WSiN with different nitrogen contents, and by varying epitaxial layer thickness and implantation dose.

  3. Structural and optical properties of InGaN–GaN nanowire heterostructures grown by molecular beam epitaxy

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

    Limbach, F. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Gotschke, T. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Stoica, T. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Calarco, R. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Sutter, E. [Brookhaven National Lab., Upton, NY (United States); Ciston, J. [Brookhaven National Lab., Upton, NY (United States); Cusco, R. [Consell Superior d'Investigacions Cientifiques (CSIC), Barcelona (Spain); Artus, L. [Consell Superior d'Investigacions Cientifiques (CSIC), Barcelona (Spain); Kremling, S. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Hofling, S. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Worschech, L. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Grutzmacher, D. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany)

    2011-01-07T23:59:59.000Z

    InGaN/GaN nanowire (NW) heterostructures grown by plasma assisted molecular beam epitaxy were studied in comparison to their GaN and InGaN counterparts. The InGaN/GaN heterostructure NWs are composed of a GaN NW, a thin InGaN shell, and a multifaceted InGaN cap wrapping the top part of the GaN NW. High-resolution transmission electron microscopy (HRTEM) images taken from different parts of a InGaN/GaN NW show a wurtzite structure of the GaN core and the epitaxial InGaN shell around it, while additional crystallographic domains are observed whithin the InGaN cap region. Large changes in the lattice parameter along the wire, from pure GaN to higher In concentration demonstrate the successful growth of a complex InGaN/GaN NW heterostructure. Photoluminescence (PL) spectra of these heterostructure NW ensembles show rather broad and intense emission peak at 2.1 eV. However, ?-PL spectra measured on single NWs reveal a reduced broadening of the visible luminescence. The analysis of the longitudinal optical phonon Raman peak position and its shape reveal a variation in the In content between 20% and 30%, in agreement with the values estimated by PL and HRTEM investigations. The reported studies are important for understanding of the growth and properties of NW heterostructures suitable for applications in optoelectronics and photovoltaics.

  4. Necessity of Ga prelayers in GaAs/Ge growth using gas-source molecular beam epitaxy

    E-Print Network [OSTI]

    in a highly defective GaAs layer.as5 Recently, InGaP light-emitting diodes have been fabricated on Si using

  5. High-efficiency radiation-resistant InGaP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Takamoto, T. [Toyota Technological Inst., Tempaku, Nagoya (Japan); [Japan Energy Corp., Toda, Saitama (Japan); Yamaguchi, M.; Taylor, S.J. [Toyota Technological Inst., Tempaku, Nagoya (Japan); Ikeda, E.; Agui, T.; Kurita, H. [Japan Energy Corp., Toda, Saitama (Japan)

    1997-12-31T23:59:59.000Z

    A world-record efficiency of 26.9% (AM0, 28 C) has been obtained for InGaP/GaAs tandem solar cells fabricated by the MOCVD method. The radiation resistance of the InGaP/GaAs tandem solar cells has also been evaluated following 1 MeV electron irradiation. Degradation in the tandem cell performance has been confirmed to be mainly attributed to large degradation in the GaAs bottom cell, which features a highly doped base layer. Similar radiation-resistance with GaAs-on-Ge cells has been observed for the InGaP/GaAs tandem cell. However, some recovery of the tandem cell performance has been found due to minority-carrier injection under light illumination of forward bias, which causes defect annealing in InGaP cells. The optimal design of the InGaP base layer thickness for current matching at end of life (EOL) (after irradiation with 10{sup 15} electrons cm{sup {minus}2}) has been examined.

  6. Highly uniform, multi-stacked InGaAs/GaAs quantum dots embedded in a GaAs nanowire

    SciTech Connect (OSTI)

    Tatebayashi, J., E-mail: tatebaya@iis.u-tokyo.ac.jp; Ota, Y. [NanoQUINE, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Ishida, S.; Nishioka, M.; Iwamoto, S.; Arakawa, Y. [NanoQUINE, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2014-09-08T23:59:59.000Z

    We demonstrate a highly uniform, dense stack of In{sub 0.22}Ga{sub 0.78}As/GaAs quantum dot (QD) structures in a single GaAs nanowire (NW). The size (and hence emission energy) of individual QD is tuned by careful control of the growth conditions based on a diffusion model of morphological evolution of NWs and optical characterization. By carefully tailoring the emission energies of individual QD, dot-to-dot inhomogeneous broadening of QD stacks in a single NW can be as narrow as 9.3?meV. This method provides huge advantages over traditional QD stack using a strain-induced Stranski-Krastanow growth scheme. We show that it is possible to fabricate up to 200 uniform QDs in single GaAs NWs using this growth technique without degradation of the photoluminescence intensity.

  7. Strain induced variations in band offsets and built-in electric fields in InGaN/GaN multiple quantum wells

    E-Print Network [OSTI]

    Alpay, S. Pamir

    Strain induced variations in band offsets and built-in electric fields in InGaN/GaN multiple InxGa1-xN(InGaN)/GaN multilayers on the In composition and misfit strain. The results indicate that for non-polar m-plane configurations with ½1210InGaN//½1210GaN and ½0001InGaN//½0001GaN epitaxial

  8. Multi-bands photoconductive response in AlGaN/GaN multiple quantum wells

    SciTech Connect (OSTI)

    Chen, G.; Rong, X.; Xu, F. J.; Tang, N. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Wang, X. Q., E-mail: wangshi@pku.edu.cn; Shen, B., E-mail: bshen@pku.edu.cn [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Fu, K.; Zhang, B. S. [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Ruoshui Road 398, 215123 Suzhou (China); Hashimoto, H.; Yoshikawa, A. [Center for SMART Green Innovation Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Ge, W. K. [Department of Physics, Tsinghua University, Beijing 100871 (China)

    2014-04-28T23:59:59.000Z

    Based on the optical transitions among the quantum-confined electronic states in the conduction band, we have fabricated multi-bands AlGaN/GaN quantum well infrared photodetectors. Crack-free AlGaN/GaN multiple quantum wells (MQWs) with atomically sharp interfaces have been achieved by inserting an AlN interlayer, which releases most of the tensile strain in the MQWs grown on the GaN underlayer. With significant reduction of dark current by using thick AlGaN barriers, photoconductive responses are demonstrated due to intersubband transition in multiple regions with center wavelengths of 1.3, 2.3, and 4??m, which shows potential applications on near infrared detection.

  9. High-performance InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Tsai, J.-H. [National Kaohsiung Normal University, Department of Electronic Engineering (China)], E-mail: jhtsai@nknucc.nknu.edu.tw; Chiu, S.-Y.; Lour, W.-S. [National Taiwan Ocean University, Department of Electrical Engineering (China); Guo, D.-F. [Air Force Academy, Department of Electronic Engineering (China)

    2009-07-15T23:59:59.000Z

    In this article, a novel InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor is first demonstrated. Though the valence band discontinuity at InGaP/GaAs heterojunction is relatively large, the addition of a {delta}-doped sheet between two spacer layers at the emitter-base (E-B) junction effectively eliminates the potential spike and increases the confined barrier for electrons, simultaneously. Experimentally, a high current gain of 25 and a relatively low E-B offset voltage of 60 mV are achieved. The offset voltage is much smaller than the conventional InGaP/GaAs pnp HBT. The proposed device could be used for linear amplifiers and low-power complementary integrated circuit applications.

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

    SciTech Connect (OSTI)

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

    2014-04-24T23:59:59.000Z

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

  11. Effect of polarization on intersubband transition in AlGaN/GaN multiple quantum wells

    SciTech Connect (OSTI)

    Chen, G.; Li, Z. L.; Wang, X. Q.; Huang, C. C.; Rong, X.; Xu, F. J.; Tang, N.; Qin, Z. X.; Shen, B. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Sang, L. W.; Sumiya, M. [Optical and Electronic Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [Optical and Electronic Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Chen, Y. H. [Laboratory of Semiconductor Material Science, Institute of Semiconductors, CAS, Beijing 100083 (China)] [Laboratory of Semiconductor Material Science, Institute of Semiconductors, CAS, Beijing 100083 (China); Ge, W. K. [Department of Physics, Tsinghua University, Beijing 100871 (China)] [Department of Physics, Tsinghua University, Beijing 100871 (China)

    2013-05-13T23:59:59.000Z

    Intersubband transitions (ISBT) of AlGaN/GaN multiple quantum wells (MQWs) with wavelength towards atmospheric window (3-5 {mu}m) have been investigated. A Ga-excess epitaxial method is used in the molecular beam epitaxy leading to ultra-sharp interface and negligible elements inter-diffusion. The absorption peak wavelength of the ISBT was successfully tuned in the range of 3-4 {mu}m by modifying the GaN well thickness from 2.8 to 5.5 nm. It was further found that the polarization charge density of the AlGaN/GaN MQWs was about -0.034 C/m{sup 2} which gave rise to blueshift of the ISBT wavelength and thus partially compensated its redshift with increasing well thickness.

  12. InGaN/GaN single-quantum-well microdisks

    SciTech Connect (OSTI)

    Hsu, Yu-Chi; Lo, Ikai; Shih, Cheng-Hung; Pang, Wen-Yuan; Hu, Chia-Hsuan; Wang, Ying-Chieh; Chou, Mitch M. C. [Department of Physics, Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China)

    2012-06-11T23:59:59.000Z

    We have grown In{sub x}Ga{sub 1-x}N/GaN quantum wells atop GaN microdisk with {gamma}-LiAlO{sub 2} substrate by using plasma-assisted molecular beam epitaxy. The structural and optical properties of the samples were analyzed by transmission electron microscopy, x-ray diffraction, cathodoluminescence, and photoluminescence measurements. Based on the measured results, we obtained the indium concentration of the In{sub x}Ga{sub 1-x}N/GaN single quantum well to be x = 0.25 with a band-gap energy of 2.31 eV, which is consistent with the bowing effect of bulk In{sub x}Ga{sub 1-x}N: E{sub g}(x) = [3.42 - x * 2.65 - x * (1 - x) * 2.4] eV.

  13. Atomic layer deposition of GaN using GaCl3 and NH3 Oh Hyun Kim, Dojun Kim, and Tim Andersona

    E-Print Network [OSTI]

    Anderson, Timothy J.

    be grown at lower temperature than by CVD. As example, ALD growth of device quality GaAs, GaP, and InGaP

  14. Dependence of the ground-state transition energy versus optical pumping in GaAsSb/InGaAs/GaAs heterostructures

    SciTech Connect (OSTI)

    Morozov, S. V.; Kryzhkov, D. I., E-mail: krizh@ipmras.ru; Aleshkin, V. Ya. [Institute for Physics of Microstructures, RAS, 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod (Russian Federation); Yablonsky, A. N.; Krasilnik, Z. F. [Institute for Physics of Microstructures, RAS, 603950 Nizhny Novgorod (Russian Federation); Zvonkov, B. N.; Vikhrova, O. V. [Physical-Technical Research Institute, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod (Russian Federation)

    2014-01-13T23:59:59.000Z

    In this work, we report on the time-resolved photoluminescence studies of a double quantum well In{sub 0.2}Ga{sub 0.8}As/GaAs{sub 0.8}Sb{sub 0.2}/GaAs heterostructure which, in contrast to the GaAsSb/GaAs structures, is expected to provide effective confinement of electrons due to additional InGaAs layer. The studies at 4.2?K have revealed a complicated nonmonotonic dependence of the ground-state transition energy on the concentration of nonequilibrium charge carriers in the quantum well. The effect observed in this work is important in terms of creating sources of radiation, including stimulated emission, on the basis of InGaAs/GaAsSb/GaAs structures.

  15. AlGaN/GaN field effect transistors for power electronics—Effect of finite GaN layer thickness on thermal characteristics

    SciTech Connect (OSTI)

    Hodges, C., E-mail: chris.hodges@bristol.ac.uk; Anaya Calvo, J.; Kuball, M. [H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom)] [H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom); Stoffels, S.; Marcon, D. [IMEC, Kapeldreef 75, B3001 Leuven (Belgium)] [IMEC, Kapeldreef 75, B3001 Leuven (Belgium)

    2013-11-11T23:59:59.000Z

    AlGaN/GaN heterostructure field effect transistors with a 150?nm thick GaN channel within stacked Al{sub x}Ga{sub 1?x}N layers were investigated using Raman thermography. By fitting a thermal simulation to the measured temperatures, the thermal conductivity of the GaN channel was determined to be 60?W m{sup ?1} K{sup ?1}, over 50% less than typical GaN epilayers, causing an increased peak channel temperature. This agrees with a nanoscale model. A low thermal conductivity AlGaN buffer means the GaN spreads heat; its properties are important for device thermal characteristics. When designing power devices with thin GaN layers, as well as electrical considerations, the reduced channel thermal conductivity must be considered.

  16. InGaAsP/InGaP buried heterostructure lasers at 810 nm

    SciTech Connect (OSTI)

    Wakao, K.; Isozumi, S.; Nishi, H.; Ohsaka, S.

    1984-12-01T23:59:59.000Z

    InGaAsP/InGaP buried heterostructure lasers emitting at 810 nm have been grown on GaAs substrates using two-step liquid-phase epitaxy. A threshold current of 79 mA and an external differential quantum efficiency of 26% are obtained. Fundamental transverse mode operation up to 3 mW is achieved in the laser with the active region of 3.5 ..mu..m wide.

  17. Simplified 2DEG carrier concentration model for composite barrier AlGaN/GaN HEMT

    SciTech Connect (OSTI)

    Das, Palash, E-mail: d.palash@gmail.com; Biswas, Dhrubes, E-mail: d.palash@gmail.com [Indian Institute of Technology Kharagpur, Kharagpur - 721302, West Bengal (India)

    2014-04-24T23:59:59.000Z

    The self consistent solution of Schrodinger and Poisson equations is used along with the total charge depletion model and applied with a novel approach of composite AlGaN barrier based HEMT heterostructure. The solution leaded to a completely new analytical model for Fermi energy level vs. 2DEG carrier concentration. This was eventually used to demonstrate a new analytical model for the temperature dependent 2DEG carrier concentration in AlGaN/GaN HEMT.

  18. Ohmic contacts to n-GaSb

    E-Print Network [OSTI]

    Yang, Zhengchong

    1997-01-01T23:59:59.000Z

    In recent years, the Ill-V semiconductor GaSb and its ternary alloys containing antimony have exhibited interesting electrical and optical properties for device applications which include negative resistance tunnel devices, lasers, detectors and FET...

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

    SciTech Connect (OSTI)

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

    1985-05-01T23:59:59.000Z

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

  20. Suggested guidelines for anti-islanding screening.

    SciTech Connect (OSTI)

    Ellis, Abraham; Ropp, Michael

    2012-02-01T23:59:59.000Z

    As increasing numbers of photovoltaic (PV) systems are connected to utility systems, distribution engineers are becoming increasingly concerned about the risk of formation of unintentional islands. Utilities desire to keep their systems secure, while not imposing unreasonable burdens on users wishing to connect PV. However, utility experience with these systems is still relatively sparse, so distribution engineers often are uncertain as to when additional protective measures, such as direct transfer trip, are needed to avoid unintentional island formation. In the absence of such certainty, utilities must err on the side of caution, which in some cases may lead to the unnecessary requirement of additional protection. The purpose of this document is to provide distribution engineers and decision makers with guidance on when additional measures or additional study may be prudent, and also on certain cases in which utilities may allow PV installations to proceed without additional study because the risk of an unintentional island is extremely low. The goal is to reduce the number of cases of unnecessary application of additional protection, while giving utilities a basis on which to request additional study in cases where it is warranted.

  1. Resuspension studies in the Marshall Islands

    SciTech Connect (OSTI)

    Shinn, J.H.; Homan, D.N.; Robison, W.L. [Lawrence Livermore National Lab., CA (United States)

    1997-07-01T23:59:59.000Z

    The contribution of inhalation exposure to the total dose for residents of the Marshall Islands was monitored at occasions of opportunity on several islands in the Bikini and Enewetak Atolls. To determine the long-term potential for inhalation exposure, and to understand the mechanisms of redistribution and personal exposure, additional investigations were undertaken on Bikini Island under modified and controlled conditions. Experiments were conducted to provide key parameters for the assessment of inhalation exposure from plutonium-contaminated dust aerosols: characterization of the contribution of plutonium in soil-borne aerosols as compared to sea spray and organic aerosols, determination of plutonium resuspension rates as measured by the meteorological flux-gradient method during extreme conditions of a bare-soil vs. a stabilized surface, determination of the approximate individual exposures to resuspended plutonium by traffic, and studies of exposures to individuals in different occupational environments simulated by personal air sampling of workers assigned to a variety of tasks. Enhancement factors (defined as ratios of the plutonium-activity), of suspended aerosols relative to the plutonium-activity of the soil were determined to be less than 1 (typically 0.4 to 0.7) in the undisturbed, vegetated areas, but greater than 1 (as high as 3) for the case studies of disturbed bare soil, roadside travel, and for occupational duties in fields and in and around houses. 12 refs., 5 figs., 8 tabs.

  2. Over 30{percent} efficient InGaP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Takamoto, T.; Ikeda, E.; Kurita, H. [Central Research Laboratory, Japan Energy Corporation, 3-17-35 Niizo-Minami, Toda, Saitama 335 (Japan)] [Central Research Laboratory, Japan Energy Corporation, 3-17-35 Niizo-Minami, Toda, Saitama 335 (Japan); Ohmori, M. [Japan Energy Research Center Company, Ltd., 1-11-9 Azabudai, Minato-ku, Tokyo 106 (Japan)] [Japan Energy Research Center Company, Ltd., 1-11-9 Azabudai, Minato-ku, Tokyo 106 (Japan)

    1997-01-01T23:59:59.000Z

    A two-terminal monolithic InGaP/GaAs tandem solar cell with a new efficiency record of 30.28{percent} is realized with a practical large area of 4 cm{sup 2} under one-sun air-mass 1.5 global illumination. We report improvements of the tandem cell performance by introducing a double-hetero (hereafter DH) structure InGaP tunnel junction, in which the InGaP layers are surrounded by high band gap AlInP barriers. The DH structure by AlInP barriers increase the peak current of InGaP tunnel junction. The AlInP barrier directly below the InGaP top cell, which takes the part of a back surface field (hereafter BSF) layer, is found to be considerably effective in reflecting minority carriers in the top cell. The AlInP BSF layer does not only form a high potential barrier but also prevents the diffusion of zinc from a high doped tunnel junction toward the top cell during epitaxial growth. Furthermore, an InGaP tunnel junction reduces the absorption loss, which exists in a GaAs tunnel junction, and increases the photogenerated current in the GaAs bottom cell. {copyright} {ital 1997 American Institute of Physics.}

  3. GaTe semiconductor for radiation detection

    DOE Patents [OSTI]

    Payne, Stephen A. (Castro Valley, CA); Burger, Arnold (Nashville, TN); Mandal, Krishna C. (Ashland, MA)

    2009-06-23T23:59:59.000Z

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

  4. Probing temperature gradients within the GaN buffer layer of AlGaN/GaN high electron mobility transistors with Raman thermography

    SciTech Connect (OSTI)

    Hodges, C., E-mail: chris.hodges@bristol.ac.uk; Pomeroy, J.; Kuball, M. [H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom)

    2014-02-14T23:59:59.000Z

    We demonstrate the ability of confocal Raman thermography using a spatial filter and azimuthal polarization to probe vertical temperature gradients within the GaN buffer layer of operating AlGaN/GaN high electron mobility transistors. Temperature gradients in the GaN layer are measured by using offset focal planes to minimize the contribution from different regions of the GaN buffer. The measured temperature gradient is in good agreement with a thermal simulation treating the GaN thermal conductivity as homogeneous throughout the layer and including a low thermal conductivity nucleation layer to model the heat flow between the buffer and substrate.

  5. A Statistical Model of Magnetic Islands in a Large Current Layer

    E-Print Network [OSTI]

    Fermo, R L; Swisdak, M

    2009-01-01T23:59:59.000Z

    We develop a statistical model describing the dynamics of magnetic islands in very large current layers that develop in space plasma. Two parameters characterize the island distribution: the flux contained in the island and the area it encloses. We derive an integro-differential evolution equation for this distribution function, based on rules that govern the small-scale generation of secondary islands, the rates of island growth, and island merging. Our numerical solutions of this equation produce island distributions relevant to the magnetosphere and corona. We also derive and analytically solve a differential equation for large islands that explicitly shows the role merging plays in island growth.

  6. Thermoelectric effects in wurtzite GaN and AlxGa1-xN alloys and Alexander A. Balandin

    E-Print Network [OSTI]

    with the active thermoelectric cooling implemented on the same material system can improve the device performance, for the pro- posed cooling system should also be based on GaN. To real- ize this, the high-efficiency Ga,6 Great progress has been achieved in GaN-based microwave technology. GaN transistors with very high

  7. Journal of Crystal Growth 298 (2007) 272275 Dislocation analysis in homoepitaxial GaInN/GaN light emitting

    E-Print Network [OSTI]

    Wetzel, Christian M.

    2007-01-01T23:59:59.000Z

    of GaInN/GaN-based light emitting diodes (LED) on quasi-bulk GaN with an atomically flat polished were much improved. The optical output power of the light emitting diode increased by more than one. Cathodoluminescence; A1. Threading dislocation density; A2. Homoepitaxial growth; B1. GaInN; B3. Light emitting diode

  8. The Effect of the Thermal Boundary Resistance on Self-Heating of AlGaN/GaN HFETs

    E-Print Network [OSTI]

    The Effect of the Thermal Boundary Resistance on Self-Heating of AlGaN/GaN HFETs 1. Introduction, performance of these devices has been limited by self-heating [1] [6]. Thus, accurate modeling of heat diffusion and self-heating effects in AlGaN/GaN heterostructures and device optimization based

  9. InAsGaPInGaP high-temperature power Schottky rectifier and J. M. Woodall

    E-Print Network [OSTI]

    Woodall, Jerry M.

    °C. Further improvement of the thermal stability is expected to be achieved by reducing the diffusion is thought to be due to strong covalent bonding at the InAs/GaP interface. The InAs/GaP heterointerface effectively blocks impurity diffusion. Since InGaP is superior to GaP for high-power applica- tions, as shown

  10. GaAs-based self-aligned laser incorporating InGaP opto-electronic confinement layer

    E-Print Network [OSTI]

    GaAs-based self-aligned laser incorporating InGaP opto-electronic confinement layer K.M. Groom, B fabrication, is demonstrated. An n-doped InGaP layer is utilised for both electrical and optical confinement-doped InGaP current blocking layer that also provides optical confinement. This tech- nology relies

  11. GaN/ZnO and AlGaN/ZnO heterostructure LEDs: growth, fabrication, optical and electrical characterization

    E-Print Network [OSTI]

    Wetzel, Christian M.

    GaN/ZnO and AlGaN/ZnO heterostructure LEDs: growth, fabrication, optical and electrical 12180-3590, U.S.A. ABSTRACT The wide bandgap polar semiconductors GaN and ZnO and their related alloys fields, and surface terminations. With a small lattice mismatch of ~1.8 % between GaN and Zn

  12. Direct Evidence of Nanoscale Carrier Localization in InGaN/GaN Structures Grown on Si Substrates

    E-Print Network [OSTI]

    Nabben, Reinhard

    Direct Evidence of Nanoscale Carrier Localization in InGaN/GaN Structures Grown on Si Substrates: time-resolved photoluminescence, quantum dots, InGaN, Si substrate There exists a strong continuous expensive and are limited in size. Thus, heteroepitaxial growth of GaN on silicon substrates seems

  13. Inclined dislocation-pair relaxation mechanism in homoepitaxial green GaInN/GaN light-emitting diodes

    E-Print Network [OSTI]

    Wetzel, Christian M.

    -emitting diodes LEDs on low-defect density bulk GaN substrate, but not in green LEDs on sapphire substrate an ideal substrate for homoepitaxial growth. Here we study the microstructural properties of green GaInN/GaN-Koehler force10 resulting from a macroscopic relaxation of strain. II. CRYSTAL GROWTH c plane bulk GaN substrate

  14. Junction Temperature Measurements and Thermal Modeling of GaInN/GaN Quantum Well Light-Emitting Diodes

    E-Print Network [OSTI]

    Wetzel, Christian M.

    quantum well (QW) light-emitting diodes (LEDs) grown on sapphire and bulk GaN substrate by micro efficiency in dies grown on GaN substrates with a thermal resistance of 75 K/W. For dies on sapphire of GaN-based blue and green LEDs grown on sapphire and GaN substrates using micro-Raman spectroscopy

  15. Correlation between structural properties and optical amplification in InGaN/GaN heterostructures grown by molecular beam epitaxy

    E-Print Network [OSTI]

    Nabben, Reinhard

    . The lateral homogeneity can be drastically improved using a template of GaN grown on the sapphire substrate-grown heterostructures can drastically be reduced by using a template of MOVPE-GaN on the sapphire substrate, which leadsCorrelation between structural properties and optical amplification in InGaN/GaN heterostructures

  16. SURFACE REMEDIATION IN THE ALEUTIAN ISLANDS: A CASE STUDY OF AMCHITKA ISLAND, ALASKA

    SciTech Connect (OSTI)

    Giblin, M. O.; Stahl, D. C.; Bechtel, J. A.

    2002-02-25T23:59:59.000Z

    Amchitka Island, Alaska, was at one time an integral player in the nation's defense program. Located in the North Pacific Ocean in the Aleutian Island archipelago, the island was intermittently inhabited by several key government agencies, including the U.S. Army, the U.S. Atomic Energy Commission (predecessor agency to the U.S. Department of Energy), and the U.S. Navy. Since 1993, the U.S. Department of Energy (DOE) has conducted extensive investigations on Amchitka to determine the nature and extent of contamination resulting from historic nuclear testing. The uninhabited island was the site of three high-yield nuclear tests from 1965 to 1971. These test locations are now part of the DOE's National Nuclear Security Administration Nevada Operations Office's Environmental Management Program. In the summer of 2001, the DOE launched a large-scale remediation effort on Amchitka to perform agreed-upon corrective actions to the surface of the island. Due to the lack of resources available on Amchitka and logistical difficulties with conducting work at such a remote location, the DOE partnered with the Navy and U.S. Army Corps of Engineers (USACE) to share certain specified costs and resources. Attempting to negotiate the partnerships while organizing and implementing the surface remediation on Amchitka proved to be a challenging endeavor. The DOE was faced with unexpected changes in Navy and USACE scope of work, accelerations in schedules, and risks associated with construction costs at such a remote location. Unfavorable weather conditions also proved to be a constant factor, often slowing the progress of work. The Amchitka Island remediation project experience has allowed the DOE to gain valuable insights into how to anticipate and mitigate potential problems associated with future remediation projects. These lessons learned will help the DOE in conducting future work more efficiently, and can also serve as a guide for other agencies performing similar work.

  17. Harbour Island: The Comparative Archaeology of a Maritime Community 

    E-Print Network [OSTI]

    Hatch, Heather E

    2013-08-01T23:59:59.000Z

    Marie Neilly and the Westley Methodist Church of Harbour Island, Pat Barry, Jeremy Clark, and Wade Higgs and Brenda Clark Higgs. Many others in the community also provided support and encouragement, and I am deeply grateful to them as well. v I... Street Higgs House (DHH)???????????????????... 154 Maritime Cultural Landscape of Harbour Island?????????????... 157 Summary????????????????????????????? 162 CHAPTER VI PATTERNS OF CULTURE AT HARBOUR ISLAND ...................... 163 Kitchen Group...

  18. Ultra-high frequency photoconductivity decay in GaAs/Ge/GaAs double heterostructure grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Hudait, M. K.; Zhu, Y. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Johnston, S. W. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)] [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Maurya, D.; Priya, S. [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States); Umbel, R. [Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-03-04T23:59:59.000Z

    GaAs/Ge/GaAs double heterostructures (DHs) were grown in-situ using two separate molecular beam epitaxy chambers. High-resolution x-ray rocking curve demonstrates a high-quality GaAs/Ge/GaAs heterostructure by observing Pendelloesung oscillations. The kinetics of the carrier recombination in Ge/GaAs DHs were investigated using photoconductivity decay measurements by the incidence excitation from the front and back side of 15 nm GaAs/100 nm Ge/0.5 {mu}m GaAs/(100)GaAs substrate structure. High-minority carrier lifetimes of 1.06-1.17 {mu}s were measured when excited from the front or from the back of the Ge epitaxial layer, suggests equivalent interface quality of GaAs/Ge and Ge/GaAs. Wavelength-dependent minority carrier recombination properties are explained by the wavelength-dependent absorption coefficient of Ge.

  19. Metastable states in InGaN/GaN MQW structures doped with Sm, Eu, and Eu + Sm

    SciTech Connect (OSTI)

    Mezdrogina, M. M., E-mail: Margaret.M@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Kozhanova, Yu. V. [St. Petersburg State Polytechnical University (Russian Federation)

    2013-04-15T23:59:59.000Z

    Measurements of the microphotoluminescence (microPL) spectra of InGaN/GaN:Sm and InGaN/GaN:Eu quantum well (QW) structures show that the action of a magnetic field gives rise to Van Vleck paramagnetism for Eu{sup 3+} and Sm{sup 3+}. The macrophotoluminescence (macroPL) spectra recorded after measuring the microPL spectra of InGaN/GaN QW structures doped with Sm or Eu + Sm at a high excitation level (>10{sup 23} photons cm{sup -2} s{sup -1}) in magnetic fields contain no QW emission lines which are present in the macroPL spectra recorded before these microPL measurements. This is indicative of the presence of photoinduced defects. Annealing of the InGaN/GaN:Sm and InGaN/GaN:(Eu + Sm) structures reduces the concentration of photoinduced defects.

  20. Gas-source molecular beam epitaxial growth and characterization of the (Al,In,Ga)NP/GaP material system and Its applications to light-emitting diodes

    E-Print Network [OSTI]

    Odnoblyudov, Vladimir

    2006-01-01T23:59:59.000Z

    on metamorphic growth of InGaP layers on GaP substrates, astemperature amber photoluminescence from InGaP QWs, grownon a metamorphic InGaP layer. References: Fred Shubert E. ,

  1. InGaN/GaN tunnel junctions for hole injection in GaN light emitting diodes

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram, E-mail: krishnamoorthy.13@osu.edu, E-mail: rajan@ece.osu.edu; Akyol, Fatih [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Rajan, Siddharth, E-mail: krishnamoorthy.13@osu.edu, E-mail: rajan@ece.osu.edu [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2014-10-06T23:59:59.000Z

    InGaN/GaN tunnel junction contacts were grown using plasma assisted molecular beam epitaxy (MBE) on top of a metal-organic chemical vapor deposition (MOCVD)-grown InGaN/GaN blue (450?nm) light emitting diode. A voltage drop of 5.3?V at 100?mA, forward resistance of 2 × 10{sup ?2} ? cm{sup 2}, and a higher light output power compared to the reference light emitting diodes (LED) with semi-transparent p-contacts were measured in the tunnel junction LED (TJLED). A forward resistance of 5?×?10{sup ?4} ? cm{sup 2} was measured in a GaN PN junction with the identical tunnel junction contact as the TJLED, grown completely by MBE. The depletion region due to the impurities at the regrowth interface between the MBE tunnel junction and the MOCVD-grown LED was hence found to limit the forward resistance measured in the TJLED.

  2. antilles island arc: Topics by E-print Network

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

    The morphology of the underthrust oceanic crust controls the mag matic activity of the island arc, and particularly the development, in space and time, of "arc compartments." Denis...

  3. Comparison of Secondary Islands in Collisional Reconnection to Hall Reconnection

    SciTech Connect (OSTI)

    Shepherd, L. S.; Cassak, P. A. [Department of Physics, West Virginia University, Morgantown, West Virginia, 26506 (United States)

    2010-07-02T23:59:59.000Z

    Large-scale resistive Hall-magnetohydrodynamic simulations of the transition from Sweet-Parker (collisional) to Hall (collisionless) magnetic reconnection are presented; the first to separate secondary islands from collisionless effects. Three main results are described. There exists a regime with secondary islands but without collisionless effects, and the reconnection rate is faster than Sweet-Parker, but significantly slower than Hall reconnection. This implies that secondary islands do not cause the fastest reconnection rates. The onset of Hall reconnection ejects secondary islands from the vicinity of the X line, implying that energy is released more rapidly during Hall reconnection. Coronal applications are discussed.

  4. Commonwealth of Northern Mariana Islands Initial Technical Assessment

    SciTech Connect (OSTI)

    Baring-Gould, I.; Hunsberger, R.; Visser, C.; Voss, P.

    2011-07-01T23:59:59.000Z

    This document is an initial energy assessment for the Commonwealth of the Northern Mariana Islands (CNMI), the first of many steps in developing a comprehensive energy strategy.

  5. Energy Office Grant Helps the Virgin Islands Environmental Resource...

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

    Office Grant Helps the Virgin Islands Environmental Resource Station Install Solar Panels, Improve Efficiency, and Cut Monthly Energy Use Nearly 30% Energy Office Grant Helps the...

  6. National Park Service - San Miguel Island, California | Department...

    Energy Savers [EERE]

    Islands National Park by conserving, recycling, using alternative fuel vehicles, applying renewable energy, and using resources wisely. It also seeks to replace conventional fuels...

  7. U.S. Virgin Islands Leadership Embraces Inclusiveness to Ensure...

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

    Leadership Embraces Inclusiveness to Ensure Community Ownership of Clean Energy Vision U.S. Virgin Islands Leadership Embraces Inclusiveness to Ensure Community Ownership of Clean...

  8. Validation in Genomics: CpG Island Methylation Revisited

    E-Print Network [OSTI]

    Segal, Mark R

    2006-01-01T23:59:59.000Z

    analysis. In: Functional Genomics: Methods and Protocols, M.Segal: Validation in Genomics: CpG Island Methylationpackage and applications to genomics. Bioinformatics and

  9. ,"Grand Island, NY Natural Gas Pipeline Imports From Canada ...

    U.S. Energy Information Administration (EIA) Indexed Site

    Imports From Canada (MMcf)" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description"," Of Series","Frequency","Latest Data for" ,"Data 1","Grand Island,...

  10. Long Island Power Authority- Commercial Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Long Island Power Authority offers a variety of incentives for its non-residential customers to increase the energy efficiency of facilities through the Commercial Efficiency Program. Major...

  11. ccsd-00000821(version1):6Nov2003 Alloy effects in Ga1-xInxN/GaN heterostructures

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ccsd-00000821(version1):6Nov2003 Alloy effects in Ga1-xInxN/GaN heterostructures Duc-Phuong Nguyen, France We show that the large band offsets between GaN and InN and the heavy carrier effec- tive masses preclude the use of the Virtual Crystal Approximation to describe the electronic structure of Ga1-xInxN/GaN

  12. DESIGN, GROWTH, FABRICATION AND CHARACTERIZATION OF HIGH-BAND GAP InGaN/GaN SOLAR CELLS

    E-Print Network [OSTI]

    Honsberg, Christiana

    DESIGN, GROWTH, FABRICATION AND CHARACTERIZATION OF HIGH-BAND GAP InGaN/GaN SOLAR CELLS Omkar Jani1 with a band gap of 2.4 eV or greater. InxGa1-xN is one of a few alloys that can meet this key requirement. InGaN.4 eV. InGaN has the appropriate optical properties and has been well demonstrated for light

  13. AlGaN/GaN MIS-HEMT Gate Structure Improvement Using Al2O3 Deposited by PEALD

    E-Print Network [OSTI]

    Boyer, Edmond

    AlGaN/GaN MIS-HEMT Gate Structure Improvement Using Al2O3 Deposited by PEALD R. Meunier1 , A, 38054 Grenoble Cedex 9, France 2 LAAS-CNRS, 7 Avenue du Colonel Roche, 31400 Toulouse, France AlGaN /GaN behavior. Those trapped charges can be associated to the carbon contamination of the AlGaN surface

  14. Emission mechanisms of bulk GaN and InGaN quantum wells prepared by lateral epitaxial overgrowth

    E-Print Network [OSTI]

    Bowers, John

    Emission mechanisms of bulk GaN and InGaN quantum wells prepared by lateral epitaxial overgrowth S for publication 5 January 1999 The emission mechanisms of bulk GaN and InGaN quantum wells QWs were studied suggest that TDs simply reduce the net volume of light-emitting area. This effect is less pronounced in InGaN

  15. Comparison of strong coupling regimes in bulk GaAs, GaN and ZnO semiconductor microcavities

    E-Print Network [OSTI]

    Boyer, Edmond

    , transmission and absorption spectra of bulk GaAs, GaN and ZnO microcavities, in order to compareComparison of strong coupling regimes in bulk GaAs, GaN and ZnO semiconductor microcavities SAs and GaN microcavities. PACS numbers: 78.67.-n, 71.36.+c, 78.20.Ci, 78.55.Cr, 78.55.Et Keywords: polariton

  16. Near ultraviolet emission from nonpolar cubic AlxGa1-xN/GaN quantum wells

    E-Print Network [OSTI]

    As, Donat Josef

    molecular beam epitaxy on free standing 3C-SiC 001 substrates. During growth of Al0.15Ga0.85N/GaN quantum growth of the quantum structures an 800 nm thick GaN buffer layer was deposited on the 3C-SiC substrate. The buffer and the c-AlGaN/GaN quantum wells were grown at a substrate temperature of 720 °C. The layers were

  17. Nanoair-bridged lateral overgrowth of GaN on ordered nanoporous GaN template

    SciTech Connect (OSTI)

    Wang, Y.D.; Zang, K.Y.; Chua, S.J.; Tripathy, S.; Chen, P.; Fonstad, C.G. [Singapore-MIT Alliance, E4-04-10, 4 Engineering Drive 3, Singapore 117576 (Singapore) and Centre for Optoelectronics, Department of Electrical and Computer Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Department of Electrical and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2005-12-19T23:59:59.000Z

    We report the growth of high-quality GaN epilayers on an ordered nanoporous GaN template by metalorganic chemical vapor deposition. The nanopores in GaN template were created by inductively coupled plasma etching using anodic aluminum oxide film as an etch mask. The average pore diameter and interpore distance is about 65 and 110 nm, respectively. Subsequent overgrowth of GaN first begins at the GaN crystallite surface between the pores, and then air-bridge-mediated lateral overgrowth leads to the formation of the continuous layer. Microphotoluminescence and micro-Raman measurements show improved optical properties and significant strain relaxation in the overgrown layer when compared to GaN layer of same thickness simultaneously grown on sapphire without any template. Similar to conventional epitaxial lateral overgrown GaN, such overgrown GaN on a nanopatterned surface would also serve as a template for the growth of ultraviolet-visible light-emitting III-nitride devices.

  18. AlGaN/GaN HEMT With 300-GHz fmax

    E-Print Network [OSTI]

    Chung, Jinwook W.

    We report on a gate-recessed AlGaN/GaN high-electron mobility transistor (HEMT) on a SiC substrate with a record power-gain cutoff frequency (f[subscript max]). To achieve this high f[subscript max], we combined a low-damage ...

  19. Gate-First AlGaN/GaN HEMT Technology for High-Frequency Applications

    E-Print Network [OSTI]

    Piner, Edwin L.

    This letter describes a gate-first AlGaN/GaN high-electron mobility transistor (HEMT) with a W/high-k dielectric gate stack. In this new fabrication technology, the gate stack is deposited before the ohmic contacts, and ...

  20. High Indium Concentration InGaN/GaN Grown on Sapphire Substrate by MOCVD

    E-Print Network [OSTI]

    Hartono, Haryono

    The InGaN system provides the opportunity to fabricate light emitting devices over the whole visible and ultraviolet spectrum due to band-gap energies E[subscript g] varying between 3.42 eV for GaN and 1.89 eV for InN. ...

  1. Schottky-Drain Technology for AlGaN/GaN High-Electron Mobility Transistors

    E-Print Network [OSTI]

    Lu, Bin

    In this letter, we demonstrate 27% improvement in the buffer breakdown voltage of AlGaN/GaN high-electron mobility transistors (HEMTs) grown on Si substrate by using a new Schottky-drain contact technology. Schottky-drain ...

  2. Investigation of Strain in AlGaN/GaN Multi Quantum Wells by Complementary Techniques

    SciTech Connect (OSTI)

    Devaraju, G.; Sathish, N.; Pathak, A. P. [School of Physics, University of Hyderabad, Central University (P.0), Hyderabad 500 046 (India); Dhamodaran, S. [Department of Physics, Indian Institute of Technology, IIT P O, Kanpur UP 208016 (India); Gaca, J.; Wojcik, M. [Institute of Electronic Materials Technology, 01-919 Warsaw, ul. Wolczynska 133 (Poland); Turos, A. [Institute of Electronic Materials Technology, 01-919 Warsaw, ul. Wolczynska 133 (Poland); Soltan Institute for Nuclear Studies, Swierk/Otwock, Warsaw (Poland); Arora, B. M. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005 (India)

    2009-03-10T23:59:59.000Z

    Al{sub 0.49}Ga{sub 0.51}N(12 nm)/GaN (13 nm) Multi Quantum Wells of 15 periods are grown on sapphire by MOCVD technique. GaN/AlN, each of thickness 200 nm and 20 nm respectively, are used as buffer layers between substrate and epilayer to incorporate the strain in epilayers. It is a well established technique to engineer the band gap in Al{sub x}Ga{sub 1-x}N by adjusting alloy composition. These samples are used in visible and UV light emitters. In the present study, we employ a photoluminescence technique to estimate the composition and luminescence peak positions of AlGaN and GaN. Crystallinity and quality of interfaces have been studied by Rocking curve scan. The Threading Dislocations formed at the GaN buffer layer travel across the entire layers to the surface to form good quality films. Photo-luminescence results show a very sharp GaN peak at 3.4 eV, as observed and reported by others, which shows that samples are free from point defects.

  3. Gallium surface diffusion on GaAs (001) surfaces measured by crystallization dynamics of Ga droplets

    SciTech Connect (OSTI)

    Bietti, Sergio, E-mail: sergio.bietti@mater.unimib.it; Somaschini, Claudio; Esposito, Luca; Sanguinetti, Stefano [L–NESS and Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 55, I–20125 Milano (Italy); Fedorov, Alexey [L–NESS and CNR–IFN, via Anzani 42, I-22100 Como (Italy)

    2014-09-21T23:59:59.000Z

    We present accurate measurements of Ga cation surface diffusion on GaAs surfaces. The measurement method relies on atomic force microscopy measurement of the morphology of nano–disks that evolve, under group V supply, from nanoscale group III droplets, earlier deposited on the substrate surface. The dependence of the radius of such nano-droplets on crystallization conditions gives direct access to Ga diffusion length. We found an activation energy for Ga on GaAs(001) diffusion E{sub A}=1.31±0.15 eV, a diffusivity prefactor of D{sub 0}?=?0.53(×2.1±1) cm{sup 2} s{sup ?1} that we compare with the values present in literature. The obtained results permit to better understand the fundamental physics governing the motion of group III ad–atoms on III–V crystal surfaces and the fabrication of designable nanostructures.

  4. Lattice-matched epitaxial GaInAsSb/GaSb thermophotovoltaic devices

    SciTech Connect (OSTI)

    Wang, C.A.; Choi, H.K.; Turner, G.W.; Spears, D.L.; Manfra, M.J. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.; Charache, G.W. [Lockheed Martin, Inc., Schenectady, NY (United States)

    1997-05-01T23:59:59.000Z

    The materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for lattice-matched thermophotovoltaic (TPV) devices is reported. Epilayers with cutoff wavelength 2--2.4 {micro}m at room temperature and lattice-matched to GaSb substrates were grown by both low-pressure organometallic vapor phase epitaxy and molecular beam epitaxy. These layers exhibit high optical and structural quality. For demonstrating lattice-matched thermophotovoltaic devices, p- and n-type doping studies were performed. Several TPV device structures were investigated, with variations in the base/emitter thicknesses and the incorporation of a high bandgap GaSb or AlGaAsSb window layer. Significant improvement in the external quantum efficiency is observed for devices with an AlGaAsSb window layer compared to those without one.

  5. Green cubic GaInN/GaN light-emitting diode on microstructured silicon (100)

    SciTech Connect (OSTI)

    Stark, Christoph J. M.; Detchprohm, Theeradetch; Wetzel, Christian, E-mail: wetzel@ieee.org [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States) [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Future Chips Constellation, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States); Lee, S. C.; Brueck, S. R. J. [Department of Electrical and Computer Engineering and Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 (United States)] [Department of Electrical and Computer Engineering and Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 (United States); Jiang, Y.-B. [Department of Earth and Planetary Science, University of New Mexico, Albuquerque, New Mexico 87131 (United States)] [Department of Earth and Planetary Science, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2013-12-02T23:59:59.000Z

    GaInN/GaN light-emitting diodes free of piezoelectric polarization were prepared on standard electronic-grade Si(100) substrates. Micro-stripes of GaN and GaInN/GaN quantum wells in the cubic crystal structure were grown on intersecting (111) planes of microscale V-grooved Si in metal-organic vapor phase epitaxy, covering over 50% of the wafer surface area. Crystal phases were identified in electron back-scattering diffraction. A cross-sectional analysis reveals a cubic structure virtually free of line defects. Electroluminescence over 20 to 100??A is found fixed at 487?nm (peak), 516?nm (dominant). Such structures therefore should allow higher efficiency, wavelength-stable light emitters throughout the visible spectrum.

  6. History on Mona Island: Long-term human and landscape dynamics of an 'uninhabited' island

    E-Print Network [OSTI]

    Samson, Alice V. M.; Cooper, Jago

    2015-05-26T23:59:59.000Z

    largely concerned with Mona’s oscillating position with respect to either one of its larger island neighbors, Puerto Rico, and the Dominican Republic/Republic of Haiti. Its archaeology has been used as a barometer to test the weather of the cultural...

  7. opinion: Political erosion dismantles the conservation network existing in the Canary Islands

    E-Print Network [OSTI]

    Fernández?Palacios, José María; de Nascimento, Lea

    2011-01-01T23:59:59.000Z

    seagrass meadows in the Canary Islands: a mul? tiscaled genetic diversity in the  Canary  Islands:  A  conservation synthesis for the Canary Islands.   Trends in Ecology and 

  8. U.S. Virgin Islands- Renewable Energy Feed-in-Tariff

    Broader source: Energy.gov [DOE]

    There is a 10 MW limit for aggregate production via feed-in-tariff contracts on the islands of St. Thomas, St. John, Water Island, and other offshore keys and islands and a similar 5 MW limit for...

  9. Large internal dipole moment in InGaN/GaN quantum dots Irina A. Ostapenko, Gerald Hnig, Christian Kindel, Sven Rodt, Andr Strittmatter et al.

    E-Print Network [OSTI]

    Nabben, Reinhard

    Large internal dipole moment in InGaN/GaN quantum dots Irina A. Ostapenko, Gerald Hönig, Christian transitions in wurtzite InGaN/GaN coupled quantum dot nanowire heterostructures with polarization internal dipole moment in InGaN/GaN quantum dots Irina A. Ostapenko,a Gerald Hönig, Christian Kindel, Sven

  10. Investigation of large Stark shifts in InGaN/GaN multiple quantum wells Guibao Xu, Guan Sun, Yujie J. Ding, Hongping Zhao, Guangyu Liu et al.

    E-Print Network [OSTI]

    Gilchrist, James F.

    Investigation of large Stark shifts in InGaN/GaN multiple quantum wells Guibao Xu, Guan Sun, Yujie overgrowth on residual strain and In incorporation in a-plane InGaN/GaN quantum wells on r- sapphire substrates J. Appl. Phys. 113, 023506 (2013) Anisotropic lattice relaxation in non-c-plane InGaN/GaN multiple

  11. Quantum confinement in GaP nanoclusters

    SciTech Connect (OSTI)

    Laurich, B.K.; Smith, D.C.; Healy, M.D.

    1994-06-01T23:59:59.000Z

    We have prepared GaP and GaAs nanoclusters from organometallic condensation reactions of E[Si(ChH{sub 3})3]3 (E = P, As) and GaCl{sub 3}. The size of the as synthesized clusters is 10 {Angstrom} to 15 {Angstrom}. Larger clusters of 20 {Angstrom} to 30 {Angstrom} size were obtained by thermal annealing of the as grown material. X-ray diffraction and transmission electron microscopy confirm the high crystalline quality. A lattice contraction of 6.7% could be seen for 10 {Angstrom} sized GaAs clusters. The clusters are nearly spherical in shape. Optical absorption spectra show a distinct line which can be assigned to the fundamental transition of the quantum confined electronic state. The measured blue shift, with respect to the GaP bulk absorption edge is 0.53 eV. As the cluster is smaller than the exciton radius, we can calculate the cluster size from this blue shift and obtain 20.2 {Angstrom}, consistent with the results from X-ray diffraction of 19.5 {Angstrom} for the same sample.

  12. Pacific Island Energy Snapshots | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed offOCHCO2:Introduction toManagementOPAM5 Accretion-of-DutiesPROPERTY3-0127 - In thePacific Island

  13. Fox Islands Wind Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489Information HydroFontana,datasetWind Farm JumpPhaseIslands

  14. Interconnecting gold islands with DNA origami

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes | National Nuclear SecurityIntellectualInterconnecting gold islands

  15. MWRA Deer Island Wind | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose Bend < MHKconverter <WAG BuoyYOG <MP2MWRA Deer Island Wind

  16. Grey Island Energy Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG ContractingGreenOrderNebraska: EnergyStrategy | OpenGreshamGrey Island

  17. Block Island Power Co | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty EditCalifornia: EnergyAvignon,Belcher HomesLyonsBirchBlock Island Power Co Jump to:

  18. Block Island Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty EditCalifornia: EnergyAvignon,Belcher HomesLyonsBirchBlock Island Power Co Jump

  19. Kauai Island Utility Cooperative | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |Jilin Zhongdiantou New Energy CoKERAFOLKarlsruheKauai Island Utility

  20. Long Island Power Authority | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |Jilin ZhongdiantouLichuan CityLiqcrytechLong Island Power Authority

  1. Falkland Islands: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 NoEurope BV Jump to:FASFMI-HDFRED TypeFairlawn,Falkland Islands:

  2. UID-GaN doping1016 cm-3 2 m 5 m2 m

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2 µm Drain Silicon UID-GaN ­ doping1016 cm-3 1.1 µm 2 µm GateSource 2 µm 5 µm2 µm AirAir Al0.25GaN ­ doping1015 cm-3 30 nm Drain Silicon UID-GaN P-GaNSource AirAir AlxGaN Drain Silicon UID-GaN GateSource AirAir AlxGaN Gate (a) (b) (c) Drain Silicon UID-GaN P-GaNSource AirAir AlxGaN Gate (d) P-GaN P-GaN 30

  3. anti-islanding method based: Topics by E-print Network

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

    Page Topic Index 1 Hybrid Anti-Islanding Algorithm for Utility Interconnection of Distributed Generation CiteSeer Summary: Abstract- In this paper hybrid anti-islanding...

  4. Proceedings of the Sixth California Islands Symposium, Ventura, California, December 1 3, 2003

    E-Print Network [OSTI]

    Silver, Whendee

    Proceedings of the Sixth California Islands Symposium, Ventura, California, December 1 ­ 3, 2003 of the Sixth California Islands Symposium, Ventura, California, December 1 ­ 3, 2003. National Park Service

  5. Data Update for Thompson Island, Boston Harbor, MA September 2005

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA September 2005 Prepared for Massachusetts for September 2005 This update summarizes the monthly data results for the Thompson Island monitoring site no maintenance issues to report. Monthly Data Time Series #12;Seen below is a graph of wind speed at Thompson

  6. Data Update for Thompson Island, Boston Harbor, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA April 2008 Prepared for Massachusetts Technology This update summarizes the monthly data results for the Thompson Island monitoring site in Boston Harbor, MA to this report if and when this happens. Monthly Data Time Series Seen below is a graph of wind speed at Thompson

  7. Data Update for Thompson Island, Boston Harbor, MA November 2005

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA November 2005 Prepared for Massachusetts for November 2005 This update summarizes the monthly data results for the Thompson Island monitoring site during the spring of 2006. Monthly Data Time Series Seen below is a graph of wind speed at Thompson

  8. Data Update for Thompson Island, Boston Harbor, MA August 2005

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA August 2005 Prepared for Massachusetts for August 2005 This update summarizes the monthly data results for the Thompson Island monitoring site no maintenance issues to report. Monthly Data Time Series #12;Seen below is a graph of wind speed at Thompson

  9. Data Update for Thompson Island, Boston Harbor, MA December 2005

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA December 2005 Prepared for Massachusetts for December 2005 This update summarizes the monthly data results for the Thompson Island monitoring site during the spring of 2006. Monthly Data Time Series Seen below is a graph of wind speed at Thompson

  10. Data Update for Thompson Island, Boston Harbor, MA October 2005

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Update for Thompson Island, Boston Harbor, MA October 2005 Prepared for Massachusetts for October 2005 This update summarizes the monthly data results for the Thompson Island monitoring site no maintenance issues to report. #12;Monthly Data Time Series Seen below is a graph of wind speed at Thompson

  11. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    of the few places in the world where rain water harvesting is required by law. Buildings are constructed and quality issues of water harvesting, development of alternative on-site sewage disposal systems and nonVirgin Islands Water Resources Research Institute Annual Technical Report FY 2013 Virgin Islands

  12. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    , rain water harvesting has been a principal source of potable water for the residents of the USVI such as rain water harvesting, alternative on-site sewage disposal systems and investigation of applicableVirgin Islands Water Resources Research Institute Annual Technical Report FY 2010 Virgin Islands

  13. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    . Historically, rain water harvesting has been a principal source of potable water for the residents of the USVI such as rain water harvesting, alternative on-site sewage disposal systems and investigation of applicableVirgin Islands Water Resources Research Institute Annual Technical Report FY 2011 Virgin Islands

  14. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    harvesting had been a principal source of potable water for the residents of the USVI with some reliance such as rain water harvesting, development of alternative on-site sewage disposal systems and investigationVirgin Islands Water Resources Research Institute Annual Technical Report FY 2012 Virgin Islands

  15. Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids Mehdi@et.aau.dk Abstract-- The concept of microgrid hierarchical control is presented, recently. In this paper, a hierarchical scheme which includes primary and secondary control levels is proposed for islanded microgrids

  16. Introduction The island of Hispaniola has reduced its malaria burden,

    E-Print Network [OSTI]

    Klein, Ophir

    Introduction The island of Hispaniola has reduced its malaria burden, with parasite prevalence feasible. The risk of imported malaria cases to the island of Hispaniola appears extremely low, e.g., fewer than 10 infections were imported from outside Hispaniola to the Dominican Republic in 2012. Based

  17. Virgin Islands Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    of the biological contamination of waters that have been used for the last 100 years have been shown to lack certainVirgin Islands Water Resources Research Institute Annual Technical Report FY 2000 Introduction The Virgin Islands Water Resources Research Institute (WRRI) is a unit of the University of the Virgin

  18. Wind resource assessment: San Nicolas Island, California

    SciTech Connect (OSTI)

    McKenna, E. [National Renewable Energy Lab., Golden, CO (United States); Olsen, T.L. [Timothy L. Olsen Consulting, (United States)

    1996-01-01T23:59:59.000Z

    San Nicolas Island (SNI) is the site of the Navy Range Instrumentation Test Site which relies on an isolated diesel-powered grid for its energy needs. The island is located in the Pacific Ocean 85 miles southwest of Los Angeles, California and 65 miles south of the Naval Air Weapons Station (NAWS), Point Mugu, California. SNI is situated on the continental shelf at latitude N33{degree}14` and longitude W119{degree}27`. It is approximately 9 miles long and 3.6 miles wide and encompasses an area of 13,370 acres of land owned by the Navy in fee title. Winds on San Nicolas are prevailingly northwest and are strong most of the year. The average wind speed is 7.2 m/s (14 knots) and seasonal variation is small. The windiest months, March through July, have wind speeds averaging 8.2 m/s (16 knots). The least windy months, August through February, have wind speeds averaging 6.2 m/s (12 knots).

  19. Carrier capture dynamics of single InGaAs/GaAs quantum-dot layers

    SciTech Connect (OSTI)

    Chauhan, K. N.; Riffe, D. M.; Everett, E. A.; Kim, D. J.; Yang, H. [Physics Department, Utah State University, Logan, Utah 84322-4415 (United States)] [Physics Department, Utah State University, Logan, Utah 84322-4415 (United States); Shen, F. K. [Center for Surface Analysis and Applications, Utah State University, Logan, Utah 84322-4415 (United States)] [Center for Surface Analysis and Applications, Utah State University, Logan, Utah 84322-4415 (United States)

    2013-05-28T23:59:59.000Z

    Using 800 nm, 25-fs pulses from a mode locked Ti:Al{sub 2}O{sub 3} laser, we have measured the ultrafast optical reflectivity of MBE-grown, single-layer In{sub 0.4}Ga{sub 0.6}As/GaAs quantum-dot (QD) samples. The QDs are formed via two-stage Stranski-Krastanov growth: following initial InGaAs deposition at a relatively low temperature, self assembly of the QDs occurs during a subsequent higher temperature anneal. The capture times for free carriers excited in the surrounding GaAs (barrier layer) are as short as 140 fs, indicating capture efficiencies for the InGaAs quantum layer approaching 1. The capture rates are positively correlated with initial InGaAs thickness and annealing temperature. With increasing excited carrier density, the capture rate decreases; this slowing of the dynamics is attributed to Pauli state blocking within the InGaAs quantum layer.

  20. Epitaxial GaN films by hyperthermal ion-beam nitridation of Ga droplets

    SciTech Connect (OSTI)

    Gerlach, J. W.; Ivanov, T.; Neumann, L.; Hoeche, Th.; Hirsch, D.; Rauschenbach, B. [Leibniz-Institut fuer Oberflaechenmodifizierung (IOM), D-04318 Leipzig (Germany)

    2012-06-01T23:59:59.000Z

    Epitaxial GaN film formation on bare 6H-SiC(0001) substrates via the process of transformation of Ga droplets into a thin GaN film by applying hyperthermal nitrogen ions is investigated. Pre-deposited Ga atoms in well defined amounts form large droplets on the substrate surface which are subsequently nitridated at a substrate temperature of 630 Degree-Sign C by a low-energy nitrogen ion beam from a constricted glow-discharge ion source. The Ga deposition and ion-beam nitridation process steps are monitored in situ by reflection high-energy electron diffraction. Ex situ characterization by x-ray diffraction and reflectivity techniques, Rutherford backscattering spectrometry, and electron microscopy shows that the thickness of the resulting GaN films depends on the various amounts of pre-deposited gallium. The films are epitaxial to the substrate, exhibit a mosaic like, smooth surface topography and consist of coalesced large domains of low defect density. Possible transport mechanisms of reactive nitrogen species during hyperthermal nitridation are discussed and the formation of GaN films by an ion-beam assisted process is explained.

  1. GaAs photoconductive semiconductor switch

    DOE Patents [OSTI]

    Loubriel, G.M.; Baca, A.G.; Zutavern, F.J.

    1998-09-08T23:59:59.000Z

    A high gain, optically triggered, photoconductive semiconductor switch (PCSS) implemented in GaAs as a reverse-biased pin structure with a passivation layer above the intrinsic GaAs substrate in the gap between the two electrodes of the device is disclosed. The reverse-biased configuration in combination with the addition of the passivation layer greatly reduces surface current leakage that has been a problem for prior PCSS devices and enables employment of the much less expensive and more reliable DC charging systems instead of the pulsed charging systems that needed to be used with prior PCSS devices. 5 figs.

  2. GaAs photoconductive semiconductor switch

    DOE Patents [OSTI]

    Loubriel, Guillermo M. (Sandia Park, NM); Baca, Albert G. (Albuquerque, NM); Zutavern, Fred J. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A high gain, optically triggered, photoconductive semiconductor switch (PCSS) implemented in GaAs as a reverse-biased pin structure with a passivation layer above the intrinsic GaAs substrate in the gap between the two electrodes of the device. The reverse-biased configuration in combination with the addition of the passivation layer greatly reduces surface current leakage that has been a problem for prior PCSS devices and enables employment of the much less expensive and more reliable DC charging systems instead of the pulsed charging systems that needed to be used with prior PCSS devices.

  3. GaN: Defect and Device Issues

    SciTech Connect (OSTI)

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

    1998-11-09T23:59:59.000Z

    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.

  4. High-temperature molecular beam epitaxial growth of AlGaN/GaN on GaN templates with reduced interface impurity levels

    SciTech Connect (OSTI)

    Koblmueller, G. [Department of Materials, University of California, Santa Barbara, California 93106 (United States); Walter Schottky Institut, Technische Universitaet Muenchen, D-85748 Garching (Germany); Chu, R. M.; Raman, A.; Mishra, U. K. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States); Speck, J. S. [Department of Materials, University of California, Santa Barbara, California 93106 (United States)

    2010-02-15T23:59:59.000Z

    We present combined in situ thermal cleaning and intentional doping strategies near the substrate regrowth interface to produce high-quality AlGaN/GaN high electron mobility transistors on semi-insulating (0001) GaN templates with low interfacial impurity concentrations and low buffer leakage. By exposing the GaN templates to an optimized thermal dissociation step in the plasma-assisted molecular beam epitaxy environment, oxygen, carbon, and, to lesser extent, Si impurities were effectively removed from the regrowth interface under preservation of good interface quality. Residual Si was further compensated by C-doped GaN via CBr{sub 4} to yield highly resistive GaN buffer layers. Improved N-rich growth conditions at high growth temperatures were then utilized for subsequent growth of the AlGaN/GaN device structure, yielding smooth surface morphologies and low residual oxygen concentration with large insensitivity to the (Al+Ga)N flux ratio. Room temperature electron mobilities of the two-dimensional electron gas at the AlGaN/GaN interface exceeded >1750 cm{sup 2}/V s and the dc drain current reached {approx}1.1 A/mm at a +1 V bias, demonstrating the effectiveness of the applied methods.

  5. Defect studies in low-temperature-grown GaAs

    SciTech Connect (OSTI)

    Bliss, D.E.

    1992-11-01T23:59:59.000Z

    High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V[sub Ga]. The neutral AsGa-related defects were measured by infrared absorption at 1[mu]m. Gallium vacancies, V[sub Ga], was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10[sup 19] cm[sup [minus]3] Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As[sub Ga] in the layer. As As[sub Ga] increases, photoquenchable As[sub Ga] decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As[sub Ga] content around 500C, similar to irradiation damaged and plastically deformed Ga[sub As], as opposed to bulk grown GaAs in which As[sub Ga]-related defects are stable up to 1100C. The lower temperature defect removal is due to V[sub Ga] enhanced diffusion of As[sub Ga] to As precipitates. The supersaturated V[sub GA] and also decreases during annealing. Annealing kinetics for As[sub Ga]-related defects gives 2.0 [plus minus] 0.3 eV and 1.5 [plus minus] 0.3 eV migration enthalpies for the As[sub Ga] and V[sub Ga]. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As[sub Ga]-related defects anneal with an activation energy of 1.1 [plus minus] 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As[sub Ga]-Be[sub Ga] pairs. Si donors can only be partially activated.

  6. PHYSICAL REVIEW B 85, 045319 (2012) Photoluminescence from In0.5Ga0.5As/GaP quantum dots coupled to photonic crystal cavities

    E-Print Network [OSTI]

    Vuckovic, Jelena

    2012-01-01T23:59:59.000Z

    in materials systems, including InP/InGaP,6­9 InP/GaP,10,11 InP/AlGaInP,12,13 GaInP/GaP,14 InAs/GaP,15 and Al have been observed only in the InP/InGaP and InP/AlGaInP systems. GaP-based materials, by contrastP compared to InGaP is preferable for on-chip frequency downconversion to telecom wavelengths. Recently,17

  7. Optical spectroscopy of quantum confined states in GaAs/AlGaAs quantum well tubes

    SciTech Connect (OSTI)

    Shi, Teng; Fickenscher, Melodie; Smith, Leigh; Jackson, Howard [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Yarrison-Rice, Jan [Department of Physics, Miami University, Oxford, OH 45056 (United States); Gao, Qiang; Tan, Hoe; Jagadish, Chennupati [Department of Electronic Materials and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Etheridge, Joanne [Monash Centre for Electron Microscopy, Monash University, Victoria, 3800 (Australia); Wong, Bryan M. [Materials Chemistry Department, Sandia National Laboratories, Livermore, CA 94551 (United States)

    2013-12-04T23:59:59.000Z

    We have investigated the quantum confinement of electronic states in GaAs/Al{sub x}Ga{sub 1?x}As nanowire heterostructures which contain radial GaAs quantum wells of either 4nm or 8nm. Photoluminescence and photoluminescence excitation spectroscopy are performed on single nanowires. We observed emission and excitation of electron and hole confined states. Numerical calculations of the quantum confined states using the detailed structural information on the quantum well tubes show excellent agreement with these optical results.

  8. Strain-induced fundamental optical transition in (In,Ga)As/GaP quantum dots

    SciTech Connect (OSTI)

    Robert, C., E-mail: cedric.robert@insa-rennes.fr, E-mail: cedric.robert@tyndall.ie; Pedesseau, L.; Cornet, C.; Jancu, J.-M.; Even, J.; Durand, O. [Université Européenne de Bretagne, INSA Rennes, France and CNRS, UMR 6082 Foton, 20 Avenue des Buttes de Coësmes, 35708 Rennes (France)] [Université Européenne de Bretagne, INSA Rennes, France and CNRS, UMR 6082 Foton, 20 Avenue des Buttes de Coësmes, 35708 Rennes (France); Nestoklon, M. O. [Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation)] [Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Pereira da Silva, K. [ICMAB-CSIC, Campus UAB, 08193 Bellaterra (Spain) [ICMAB-CSIC, Campus UAB, 08193 Bellaterra (Spain); Departamento de Física, Universidade Federal do Ceará, P.O. Box 6030, Fortaleza–CE, 60455-970 (Brazil); Alonso, M. I. [ICMAB-CSIC, Campus UAB, 08193 Bellaterra (Spain)] [ICMAB-CSIC, Campus UAB, 08193 Bellaterra (Spain); Goñi, A. R. [ICMAB-CSIC, Campus UAB, 08193 Bellaterra (Spain) [ICMAB-CSIC, Campus UAB, 08193 Bellaterra (Spain); ICREA, Passeig Lluís Companys 23, 08010 Barcelona (Spain); Turban, P. [Equipe de Physique des Surfaces et Interfaces, Institut de Physique de Rennes UMR UR1-CNRS 6251, Université de Rennes 1, F-35042 Rennes Cedex (France)] [Equipe de Physique des Surfaces et Interfaces, Institut de Physique de Rennes UMR UR1-CNRS 6251, Université de Rennes 1, F-35042 Rennes Cedex (France)

    2014-01-06T23:59:59.000Z

    The nature of the ground optical transition in an (In,Ga)As/GaP quantum dot is thoroughly investigated through a million atoms supercell tight-binding simulation. Precise quantum dot morphology is deduced from previously reported scanning-tunneling-microscopy images. The strain field is calculated with the valence force field method and has a strong influence on the confinement potentials, principally, for the conduction band states. Indeed, the wavefunction of the ground electron state is spatially confined in the GaP matrix, close to the dot apex, in a large tensile strain region, having mainly Xz character. Photoluminescence experiments under hydrostatic pressure strongly support the theoretical conclusions.

  9. Midinfrared intersubband absorption in GaN/AlGaN superlattices on Si(111) templates

    SciTech Connect (OSTI)

    Kandaswamy, P. K.; Monroy, E. [CEA/CNRS group 'Nanophysique et semiconducteurs', INAC/SP2M/NPSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Machhadani, H.; Sakr, S.; Tchernycheva, M.; Julien, F. H. [Photis, Institut d'Electronique Fondamentale, Universite Paris-Sud, 91405 Orsay Cedex (France); Bougerol, C. [CEA/CNRS group 'Nanophysique et semiconducteurs', Institut Neel, 25 rue des Martyrs, 38042 Grenoble Cedex 9 (France)

    2009-10-05T23:59:59.000Z

    We report on the observation of midinfrared intersubband absorption in Si-doped GaN/AlGaN superlattices grown by plasma-assisted molecular-beam epitaxy on semi-insulating GaN-on-Si(111) templates. TM-polarized absorption attributed to transition between the first two electronic levels in the quantum wells peaked in the range from 2 to 9 {mu}m. The relative spectral width remains around 20% in the whole midinfrared spectral range. Doping is predicted to have a large influence on the intersubband absorption energy due to screening of polarization-induced internal electric field.

  10. Cultural contributions to the island of St. John, United States Virgin Islands: underwater historical archaeology at Cruz Bay

    E-Print Network [OSTI]

    Marquez, Carmen M

    1995-01-01T23:59:59.000Z

    The United States Virgin Islands, St. Thomas, St. Croix and St. John, in the Lesser Antilles, were discovered by Christopher Columbus in November, 1493, on his second voyage. The islands were not revisited by the Spanish for over 57 years. During...

  11. Wave Power Resources off the Hawaiian Islands luisvega@hawaii.edu Wave Resources for Representative Sites Around the Hawaiian Islands

    E-Print Network [OSTI]

    Wave Power Resources off the Hawaiian Islands luisvega@hawaii.edu 1 Wave Resources for Representative Sites Around the Hawaiian Islands Table of Contents Summary p2 Background: Wave Power Conversion p3 Licensing and Permitting p3 Challenges and Barriers p4 Wave Power Resources: Previous Work p5 Wave

  12. Energy Development in Island Nations (EDIN), Partnering to Increase Island Energy Security Around the World (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-06-01T23:59:59.000Z

    This fact sheet provides an overview of the international partnership for Energy Development in Island nations, including mission, goals, and organization. It also includes background on EDIN's three pilot projects: U.S. Virgin Islands, Iceland-Dominica Collaboration, and New Zealand-Geothermal Potential in the Pacific.

  13. Energy absorption in Ni-Mn-Ga/ polymer composites

    E-Print Network [OSTI]

    Feuchtwanger, Jorge

    2006-01-01T23:59:59.000Z

    In recent years Ni-Mn-Ga has attracted considerable attention as a new kind of actuator material. Off-stoichiometric single crystals of Ni2MnGa can regularly exhibit 6% strain in tetragonal martensites and orthorhombic ...

  14. Degradation mechanisms of GaN high electron mobility transistors

    E-Print Network [OSTI]

    Joh, Jungwoo

    2007-01-01T23:59:59.000Z

    In spite of their extraordinary performance, GaN high electron mobility transistors (HEMT) have still limited reliability. In RF power applications, GaN HEMTs operate at high voltage where good reliability is essential. ...

  15. On strongly GA-convex functions and stochastic processes

    SciTech Connect (OSTI)

    Bekar, Nurgül Okur [Department of Statistics, Giresun University, Giresun (Turkey); Akdemir, Hande Günay; ??can, ?mdat [Department of Mathematics, Giresun University, Giresun (Turkey)

    2014-08-20T23:59:59.000Z

    In this study, we introduce strongly GA-convex functions and stochastic processes. We provide related well-known Kuhn type results and Hermite-Hadamard type inequality for strongly GA-convex functions and stochastic processes.

  16. TEM-Untersuchungen an GaN basierten Halbleiterheterostrukturen fur

    E-Print Network [OSTI]

    Schubart, Christoph

    TEM-Untersuchungen an GaN basierten Halbleiterheterostrukturen f¨ur optoelektronische Anwendungen . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 5.1.2 Versetzungen bei Homoapitaxie auf GaN-Substraten . . . . 79 5.2 Versetzungsreduktion durch

  17. GaN Nanopore Arrays: Fabrication and Characterization

    E-Print Network [OSTI]

    Wang, Yadong

    GaN nanopore arrays with pore diameters of approximately 75 nm were fabricated by inductively coupled plasma etching (ICP) using anodic aluminum oxide (AAO) films as etch masks. Nanoporous AAO films were formed on the GaN ...

  18. Kinematic studies of transport across an island wake, with application to the Canary islands

    E-Print Network [OSTI]

    Mathias Sandulescu; Emilio Hernandez-Garcia; Cristobal Lopez; Ulrike Feudel

    2006-05-29T23:59:59.000Z

    Transport from nutrient-rich coastal upwellings is a key factor influencing biological activity in surrounding waters and even in the open ocean. The rich upwelling in the North-Western African coast is known to interact strongly with the wake of the Canary islands, giving rise to filaments and other mesoscale structures of increased productivity. Motivated by this scenario, we introduce a simplified two-dimensional kinematic flow describing the wake of an island in a stream, and study the conditions under which there is a net transport of substances across the wake. For small vorticity values in the wake, it acts as a barrier, but there is a transition when increasing vorticity so that for values appropriate to the Canary area, it entrains fluid and enhances cross-wake transport.

  19. Distributed Wind Case Study: Cross Island Farms, Wellesley Island, New York (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-04-01T23:59:59.000Z

    Installing a small wind turbine can sometimes be difficult due to economics, zoning issues, public perception, and other barriers. Persistence and innovation, however, can result in a successful installation. Dani Baker and David Belding own Cross Island Farms, a 102-acre certified organic farm on Wellesley Island in northern New York. In 2009, they took their interest in renewable energy to the next level by researching the logistics of a small wind installation on their land to make their farm even more sustainable. Their renewable energy system consists of one 10-kilowatt Bergey Excel wind turbine, a solar array, and a propane-powered generator. This case study describes funding for the project and the installation process.

  20. Height stabilization of GaSb/GaAs quantum dots by Al-rich capping

    SciTech Connect (OSTI)

    Smakman, E. P., E-mail: e.p.smakman@tue.nl; Koenraad, P. M. [Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven (Netherlands); DeJarld, M.; Martin, A. J.; Millunchick, J. [Department of Material Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Luengo-Kovac, M.; Sih, V. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-09-01T23:59:59.000Z

    GaSb quantum dots (QDs) in a GaAs matrix are investigated with cross-sectional scanning tunneling microscopy (X-STM) and photoluminescence (PL). We observe that Al-rich capping materials prevent destabilization of the nanostructures during the capping stage of the molecular beam epitaxy (MBE) growth process and thus preserves the QD height. However, the strain induced by the absence of destabilization causes many structural defects to appear around the preserved QDs. These defects originate from misfit dislocations near the GaSb/GaAs interface and extend into the capping layer as stacking faults. The lack of a red shift in the QD PL suggests that the preserved dots do not contribute to the emission spectra. We suggest that a better control over the emission wavelength and an increase of the PL intensity is attainable by growing smaller QDs with an Al-rich overgrowth.

  1. 2DEG electrodes for piezoelectric transduction of AlGaN/GaN MEMS resonators

    E-Print Network [OSTI]

    Weinstein, Dana

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

  2. High-field quasi-ballistic transport in AlGaN/GaN heterostructures

    SciTech Connect (OSTI)

    Danilchenko, B. A.; Tripachko, N. A. [Institute of Physics, NASU, Pr. Nauki 46, Kiev 03028 (Ukraine); Belyaev, A. E. [Institute of Semiconductor Physics, NASU, Pr. Nauki 45, Kiev 03028 (Ukraine); Vitusevich, S. A., E-mail: s.vitusevich@fz-juelich.de; Hardtdegen, H.; Lüth, H. [Peter Grünberg Institute (PGI-8,PGI-9), Forschungszentrum Jülich, Jülich D-52425 (Germany)

    2014-02-17T23:59:59.000Z

    Mechanisms of electron transport formation in 2D conducting channels of AlGaN/GaN heterostructures in extremely high electric fields at 4.2?K have been studied. Devices with a narrow constriction for the current flow demonstrate high-speed electron transport with an electron velocity of 6.8?×?10{sup 7}?cm/s. Such a velocity is more than two times higher than values reported for conventional semiconductors and about 15% smaller than the limit value predicted for GaN. Superior velocity is attained in the channel with considerable carrier reduction. The effect is related to a carrier runaway phenomenon. The results are in good agreement with theoretical predictions for GaN-based materials.

  3. AlGaN/GaN High-Electron-Mobility Transistor Employing an Additional Gate for High-Voltage Switching Applications

    E-Print Network [OSTI]

    Seo, Kwang Seok

    AlGaN/GaN High-Electron-Mobility Transistor Employing an Additional Gate for High-Voltage Switching 16, 2004; accepted May 10, 2005; published September 8, 2005) We have proposed and fabricated an AlGaN/GaN: GaN, AlGaN, HEMT, switch 1. Introduction GaN has attracted attention for high-power and high

  4. Cubic AlGaN/GaN Hetero-Junction Field-Effect Transistors with Normally-on and Normally-off

    E-Print Network [OSTI]

    As, Donat Josef

    Cubic AlGaN/GaN Hetero-Junction Field-Effect Transistors with Normally-on and Normally-effect transistors (HFETs) in GaN technology. HFET structures were fabricated of non-polar cubic AlGaN/GaN hetero insulation of 3C-SiC was realized by Ar+ implantation before c-AlGaN/GaN growth. HFETs with normally

  5. A 3-10 GHZLCR-matched Power Amplifier using Flip-Chip Mounted AlGaN/GaN HEMTs

    E-Print Network [OSTI]

    York, Robert A.

    WE4A-5 A 3-10 GHZLCR-matched Power Amplifier using Flip-Chip Mounted AlGaN/GaN HEMTs Jane J a GaN-based broadband power amplifier using AlGaN/GaN-HEMTs, grown on sapphire substrates amplifier using GaN- HEMTs-on-Sapphire. I INTRODUCTION GaN HEMTs have enormous potential for realizing high

  6. IPAP Conference Series 1: IWN2000, Nov., 2000 1 Morphology Dependent Growth Kinetics of Ga-polar GaN(0001)

    E-Print Network [OSTI]

    Cohen, Philip I.

    IPAP Conference Series 1: IWN2000, Nov., 2000 1 Morphology Dependent Growth Kinetics of Ga-polar GaN, cohen@ece.umn.edu GaN grown on Ga polar GaN templates prepared by metal-organic vapor deposition shows to equilibrium models of the growth. The results indicate that Ga-polar GaN(0001) has a step energy of the order

  7. Engineering of AlGaN-Delta-GaN Quantum-Well Gain Media for Mid-and Deep-Ultraviolet Lasers

    E-Print Network [OSTI]

    Gilchrist, James F.

    Engineering of AlGaN-Delta-GaN Quantum-Well Gain Media for Mid- and Deep-Ultraviolet Lasers Volume.1109/JPHOT.2013.2248705 1943-0655/$31.00 Ó2013 IEEE #12;Engineering of AlGaN-Delta-GaN Quantum-Well Gain@Lehigh.Edu). Abstract: The gain characteristics of AlGaN-delta-GaN quantum wells (QWs) with varying delta-GaN positions

  8. Recent progress in InGaAsSb/GaSb TPV devices

    SciTech Connect (OSTI)

    Shellenbarger, Z.A.; Mauk, M.G.; DiNetta, L.C. [AstroPower, Inc., Newark, DE (United States); Charache, G.W. [Lockheed Martin Corp., Schenectady, NY (United States)

    1996-05-01T23:59:59.000Z

    AstroPower is developing InGaAsSb thermophotovoltaic (TPV) devices. This photovoltaic cell is a two-layer epitaxial InGaAsSb structure formed by liquid-phase epitaxy on a GaSb substrate. The (direct) bandgap of the In{sub 1{minus}x}Ga{sub x}As{sub 1{minus}y}Sb{sub y} alloy is 0.50 to 0.55 eV, depending on its exact alloy composition (x,y); and is closely lattice-matched to the GaSb substrate. The use of the quaternary alloy, as opposed to a ternary alloy--such as, for example InGaAs/InP--permits low bandgap devices optimized for 1,000 to 1,500 C thermal sources with, at the same time, near-exact lattice matching to the GaSb substrate. Lattice matching is important since even a small degree of lattice mismatch degrades device performance and reliability and increases processing complexity. Internal quantum efficiencies as high as 95% have been measured at a wavelength of 2 microns. At 1 micron wavelengths, internal quantum efficiencies of 55% have been observed. The open-circuit voltage at currents of 0.3 A/cm{sup 2} is 0.220 volts and 0.280 V for current densities of 2 A/cm{sup 2}. Fill factors of 56% have been measured at 60 mA/cm{sup 2}. However, as current density increases there is some decrease in fill factor. The results to date show that the GaSb-based quaternary compounds provide a viable and high performance energy conversion solution for thermophotovoltaic systems operating with 1,000 to 1,500 C source temperatures.

  9. AlGaAs/GaAs photovoltaic converters for high power narrowband radiation

    SciTech Connect (OSTI)

    Khvostikov, Vladimir; Kalyuzhnyy, Nikolay; Mintairov, Sergey; Potapovich, Nataliia; Shvarts, Maxim; Sorokina, Svetlana; Andreev, Viacheslav [Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021 (Russian Federation); Luque, Antonio [Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021, Russia and Instituto de Energia Solar, Universidad Politecnica de Madrid, Madrid (Spain)

    2014-09-26T23:59:59.000Z

    AlGaAs/GaAs-based laser power PV converters intended for operation with high-power (up to 100 W/cm{sup 2}) radiation were fabricated by LPE and MOCVD techniques. Monochromatic (? = 809 nm) conversion efficiency up to 60% was measured at cells with back surface field and low (x = 0.2) Al concentration 'window'. Modules with a voltage of 4 V and the efficiency of 56% were designed and fabricated.

  10. Sheet resistance under Ohmic contacts to AlGaN/GaN heterostructures

    SciTech Connect (OSTI)

    Haj?asz, M., E-mail: m.hajlasz@m2i.nl [Materials innovation institute (M2i), Mekelweg 2, 2628 CD, Delft (Netherlands); MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands); Donkers, J. J. T. M.; Sque, S. J.; Heil, S. B. S. [NXP Semiconductors Research, High Tech Campus 46, 5656 AE, Eindhoven (Netherlands); Gravesteijn, D. J. [NXP Semiconductors Research, High Tech Campus 46, 5656 AE, Eindhoven (Netherlands); MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands); Rietveld, F. J. R. [NXP Semiconductors, Gerstweg 2, 6534 AE, Nijmegen (Netherlands); Schmitz, J. [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands)

    2014-06-16T23:59:59.000Z

    For the determination of specific contact resistance in semiconductor devices, it is usually assumed that the sheet resistance under the contact is identical to that between the contacts. This generally does not hold for contacts to AlGaN/GaN structures, where an effective doping under the contact is thought to come from reactions between the contact metals and the AlGaN/GaN. As a consequence, conventional extraction of the specific contact resistance and transfer length leads to erroneous results. In this Letter, the sheet resistance under gold-free Ti/Al-based Ohmic contacts to AlGaN/GaN heterostructures on Si substrates has been investigated by means of electrical measurements, transmission electron microscopy, and technology computer-aided design simulations. It was found to be significantly lower than that outside of the contact area; temperature-dependent electrical characterization showed that it exhibits semiconductor-like behavior. The increase in conduction is attributed to n-type activity of nitrogen vacancies in the AlGaN. They are thought to form during rapid thermal annealing of the metal stack when Ti extracts nitrogen from the underlying semiconductor. The high n-type doping in the region between the metal and the 2-dimensional electron gas pulls the conduction band towards the Fermi level and enhances horizontal electron transport in the AlGaN. Using this improved understanding of the properties of the material underneath the contact, accurate values of transfer length and specific contact resistance have been extracted.

  11. TEM and HRXRD Analysis of LP MOVPE Grown InGaP/GaAs epilayers

    SciTech Connect (OSTI)

    Pelosi, Claudio; Bosi, Matteo; Attolini, Giovanni; Germini, Fabrizio; Frigeri, Cesare [CNR-IMEM Institute, Parco Area delle Scienze 37a, Loc Fontanini 43010 Parma (Italy); Prutskij, Tatiana [Instituto de Ciencias, BUAP, Privada 17 Norte, no. 3417, colSanMiguel Hueyotlipan, 72050 Puebla, Pue. (Mexico)

    2007-04-10T23:59:59.000Z

    The diffusion phenomena at interfaces between GaAs/InGaP layers grown by low pressure MOVPE have been studied by dark field (DF) transmission Electron Microscopy (TEM) and High resolution X-ray Diffractometry (HRXRD). By comparing the results of the two techniques a mismatched layer containing P or P and In has been evidenced. The causes of this behavior are briefly discussed.

  12. Guided Neuronal Growth on Arrays of Biofunctionalized GaAs/InGaAs Semiconductor Microtubes

    E-Print Network [OSTI]

    Cornelius S. Bausch; Aune Koitmäe; Eric Stava; Amanda Price; Pedro J. Resto; Yu Huang; David Sonnenberg; Yuliya Stark; Christian Heyn; Justin C. Williams; Erik W. Dent; Robert H. Blick

    2013-05-06T23:59:59.000Z

    We demonstrate embedded growth of cortical mouse neurons in dense arrays of semiconductor microtubes. The microtubes, fabricated from a strained GaAs/InGaAs heterostructure, guide axon growth through them and enable electrical and optical probing of propagating action potentials. The coaxial nature of the microtubes -- similar to myelin -- is expected to enhance the signal transduction along the axon. We present a technique of suppressing arsenic toxicity and prove the success of this technique by overgrowing neuronal mouse cells.

  13. InGaN/GaN quantum wells for polariton laser diodes: Role of inhomogeneous broadening

    SciTech Connect (OSTI)

    Glauser, Marlene; Mounir, Christian; Rossbach, Georg; Feltin, Eric; Carlin, Jean-François; Butté, Raphaël; Grandjean, Nicolas [École Polytechnique Fédérale de Lausanne (EPFL), Institute of Condensed Matter Physics, CH-1015 Lausanne (Switzerland)

    2014-06-21T23:59:59.000Z

    Contrary to the case of III-nitride based visible light-emitting diodes for which the inhomogeneous linewidth broadening characteristic of InGaN-based multiple quantum well (MQW) heterostructures does not appear as a detrimental parameter, such a broadening issue can prevent a microcavity (MC) system entering into the strong light-matter coupling regime (SCR). The impact of excitonic disorder in low indium content (x???0.1) In{sub x}Ga{sub 1–x}N/GaN MQW active regions is therefore investigated for the subsequent realization of polariton laser diodes by considering both simulations and optical characterizations. It allows deriving the requirements for such MQWs in terms of absorption, emission linewidth, and Stokes shift. Systematic absorption-like and photoluminescence (PL) spectroscopy experiments are performed on single and multiple In{sub 0.1}Ga{sub 0.9}N/GaN quantum wells (QWs). Micro-PL mappings reveal a low temperature PL linewidth of ?30?meV, compatible with SCR requirements, for single QWs for which the microscopic origin responsible for this broadening is qualitatively discussed. When stacking several InGaN/GaN QWs, a departure from such a narrow linewidth value and an increase in the Stokes shift are observed. Various possible reasons for this degradation such as inhomogeneous built-in field distribution among the QWs are then identified. An alternative solution for the MC design to achieve the SCR with the InGaN alloy is briefly discussed.

  14. Rapid Communications Strong piezoelectricity in individual GaN nanowires

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Rapid Communications Strong piezoelectricity in individual GaN nanowires Majid Minary@northwestern.edu (Received 12 July 2011; accepted 15 September 2011) Abstract GaN nanowires are promising building blocks piezoelectricity in individual single-crystal GaN nanowires revealed by direct measurement of the piezoelectric

  15. GaN Radiation Detectors for Particle Physics and

    E-Print Network [OSTI]

    Glasgow, University of

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

  16. New Faces of GaN: Growth, Doping and Devices

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    New Faces of GaN: Growth, Doping and Devices James S. Speck Materials Department University of California Santa Barbara, CA LEO of a-GaN from circular opening Engineering Insights 2006 #12;#12;Personnel. Wraback (ARL) $$$ JST ­ ERATO UCSB SSLDC AFOSR ONR #12;Reversed direction of polarization Bulk GaN

  17. Analysis of the AlGaN/GaN vertical bulk current on Si, sapphire, and free-standing GaN substrates

    SciTech Connect (OSTI)

    Perez-Tomas, A.; Fontsere, A.; Llobet, J. [IMB-CNM-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, CAT (Spain); Placidi, M. [IREC, Jardins Dones de Negre 1, 08930 Sant Adria de Besos, Barcelona (Spain); Rennesson, S.; Chenot, S.; Moreno, J. C.; Cordier, Y. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Baron, N. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); PICOGIGA International, Pl M. Rebuffat, Courtaboeuf 7, 91140 Villejust (France)

    2013-05-07T23:59:59.000Z

    The vertical bulk (drain-bulk) current (I{sub db}) properties of analogous AlGaN/GaN hetero-structures molecular beam epitaxially grown on silicon, sapphire, and free-standing GaN (FS-GaN) have been evaluated in this paper. The experimental I{sub db} (25-300 Degree-Sign C) have been well reproduced with physical models based on a combination of Poole-Frenkel (trap assisted) and hopping (resistive) conduction mechanisms. The thermal activation energies (E{sub a}), the (soft or destructive) vertical breakdown voltage (V{sub B}), and the effect of inverting the drain-bulk polarity have also been comparatively investigated. GaN-on-FS-GaN appears to adhere to the resistive mechanism (E{sub a} = 0.35 eV at T = 25-300 Degree-Sign C; V{sub B} = 840 V), GaN-on-sapphire follows the trap assisted mechanism (E{sub a} = 2.5 eV at T > 265 Degree-Sign C; V{sub B} > 1100 V), and the GaN-on-Si is well reproduced with a combination of the two mechanisms (E{sub a} = 0.35 eV at T > 150 Degree-Sign C; V{sub B} = 420 V). Finally, the relationship between the vertical bulk current and the lateral AlGaN/GaN transistor leakage current is explored.

  18. Subsidence at the Weeks Island SPR Facility

    SciTech Connect (OSTI)

    Bauer, S.J.

    1999-01-01T23:59:59.000Z

    The elevation change data measured at the Weeks Island SPR site over the last 16+ years has been studied and analyzed. The subsidence rate is not constant with time and while the subsidence rate may have increased slightly during the past several years, recently the rate has increased more dramatically. The most recent increase comes at a time when the Strategic Petroleum Reserve (SPR) storage mine had been emptied of oil and was in the process of being refilled with brine. Damage to surface structures that has been observed during the past 12-18 months is attributed to the continued subsidence and dtierential subsidence across structures. The recent greater subsidence rates were unanticipated according to analysis results and will be used to aid further subsidence model development.

  19. A New Combustion Synthesis Method for GaN:Eu3+ and Ga2O3 :Eu3+

    E-Print Network [OSTI]

    McKittrick, Joanna

    A New Combustion Synthesis Method for GaN:Eu3+ and Ga2O3 :Eu3+ Luminescent Powders G. A. Hirata1 between the precursors. The preparation of Eu-doped Ga2O3 powders was achieved using a new combustion)3 and Ga(NO3)3 as the precursors and hydrazine as (non-carbonaceous) fuel. A spontaneous combustion

  20. Electron mobility enhancement in AlN/GaN/AlN heterostructures with InGaN nanogrooves

    E-Print Network [OSTI]

    improve the room-temperature carrier mobility in wurtzite AlN/GaN/AlN heterostructures, which is limited consider a narrow groove made of InxGa1-xN with small In content x inside a wurtzite AlN/GaN/AlN heteroN 2 nm /GaN 3 nm /AlN 3 nm . A well-known feature of wurtzite heterostructures is a strong buit

  1. Growth of GaN on porous SiC and GaN substrates C. K. Inoki1

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Growth of GaN on porous SiC and GaN substrates C. K. Inoki1 , T. S. Kuan1 , Ashutosh Sagar2 , C, Albuquerque, NM 87185 4 Beckman Institute, University of Illinois, Urbana, IL 61801 GaN films were grown on porous SiC and GaN templates using both plasma-assisted molecular beam epitaxy (PAMBE) and metal

  2. Structural, morphological, and optical properties of AlGaN/GaN heterostructures with AlN buffer and interlayer

    E-Print Network [OSTI]

    Ozbay, Ekmel

    N buffer layer BL grown on an Al2O3 substrate and an AlN IL grown under the AlGaN ternary layer TL. In the present study, we investigate the effects of an AlN BL on an Al2O3 substrate and an AlN IL between an AlGaNStructural, morphological, and optical properties of AlGaN/GaN heterostructures with AlN buffer

  3. From Schottky to Ohmic graphene contacts to AlGaN/GaN heterostructures: Role of the AlGaN layer microstructure

    SciTech Connect (OSTI)

    Fisichella, G. [CNR-IMM, Strada VIII, 5, 95121 Catania (Italy); Department of Electronic Engineering, University of Catania, 95124 Catania (Italy); Greco, G.; Roccaforte, F.; Giannazzo, F. [CNR-IMM, Strada VIII, 5, 95121 Catania (Italy)

    2014-08-11T23:59:59.000Z

    The electrical behaviour of graphene (Gr) contacts to Al{sub x}Ga{sub 1?x}N/GaN heterostructures has been investigated, focusing, in particular, on the impact of the AlGaN microstructure on the current transport at Gr/AlGaN interface. Two Al{sub 0.25}Ga{sub 0.75}N/GaN heterostructures with very different quality in terms of surface roughness and defectivity, as evaluated by atomic force microscopy (AFM) and transmission electron microscopy, were compared in this study, i.e., a uniform and defect-free sample and a sample with a high density of typical V-defects, which locally cause a reduction of the AlGaN thickness. Nanoscale resolution current voltage (I-V) measurements by an Au coated conductive AFM tip were carried out at several positions both on the bare and Gr-coated AlGaN surfaces. Rectifying contacts were found onto both bare AlGaN surfaces, but with a more inhomogeneous and lower Schottky barrier height (?{sub B}???0.6?eV) for AlGaN with V-defects, with respect to the case of the uniform AlGaN (?{sub B}???0.9?eV). Instead, very different electrical behaviours were observed in the presence of the Gr interlayer between the Au tip and AlGaN, i.e., a Schottky contact with reduced barrier height (?{sub B} ? 0.4?eV) for the uniform AlGaN and an Ohmic contact for the AlGaN with V-defects. Interestingly, excellent lateral uniformity of the local I-V characteristics was found in both cases and can be ascribed to an averaging effect of the Gr electrode over the AlGaN interfacial inhomogeneities. Due to the locally reduced AlGaN layer thickness, V defect act as preferential current paths from Gr to the 2DEG and can account for the peculiar Ohmic behaviour of Gr contacts on defective AlGaN.

  4. Lattice-Mismatched GaAs/InGaAs Two-Junction Solar Cells by Direct Wafer Bonding

    SciTech Connect (OSTI)

    Tanabe, K.; Aiken, D. J.; Wanlass, M. W.; Morral, A. F.; Atwater, H. A.

    2006-01-01T23:59:59.000Z

    Direct bonded interconnect between subcells of a lattice-mismatched III-V compound multijunction cell would enable dislocation-free active regions by confining the defect network needed for lattice mismatch accommodation to tunnel junction interfaces, while metamorphic growth inevitably results in less design flexibility and lower material quality than is desirable. The first direct-bond interconnected multijunction solar cell, a two-terminal monolithic GaAs/InGaAs two-junction solar cell, is reported and demonstrates viability of direct wafer bonding for solar cell applications. The tandem cell open-circuit voltage was approximately the sum of the subcell open-circuit voltages. This achievement shows direct bonding enables us to construct lattice-mismatched III-V multijunction solar cells and is extensible to an ultrahigh efficiency InGaP/GaAs/InGaAsP/InGaAs four-junction cell by bonding a GaAs-based lattice-matched InGaP/GaAs subcell and an InP-based lattice-matched InGaAsP/InGaAs subcell. The interfacial resistance experimentally obtained for bonded GaAs/InP smaller than 0.10 Ohm-cm{sup 2} would result in a negligible decrease in overall cell efficiency of {approx}0.02%, under 1-sun illumination.

  5. X-ray diffraction analysis of InGaP/GaAs heterointerfaces grown by metalorganic chemical vapor deposition

    SciTech Connect (OSTI)

    Nittono, T.; Hyuga, F. [NTT System Electronics Laboratories 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-01 (Japan)] [NTT System Electronics Laboratories 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-01 (Japan)

    1997-03-01T23:59:59.000Z

    InGaP/GaAs heterointerfaces grown by metalorganic chemical vapor deposition have been characterized by a high-resolution x-ray diffraction analysis of multiple quantum well structures. The flow of AsH{sub 3} to InGaP surface produces an InGaAs-like interfacial layer at the GaAs-on-InGaP interface, indicating P atoms of the InGaP surface are easily replaced by As atoms. The flow of PH{sub 3} to GaAs surface, on the other hand, does not make any detectable interfacial layer, indicating that almost no As atoms of the GaAs surface are replaced by P atoms. It is also found that the flow of trimethylgallium (TMG) to the InGaP surface produces a GaP-like interfacial layer. This interfacial layer is probably formed by the reaction between TMG and excessive P atoms on the InGaP surface or residual PH{sub 3} in the growth chamber. {copyright} {ital 1997 American Institute of Physics.}

  6. Physica B 376377 (2006) 486490 Preferential substitution of Fe on physically equivalent Ga sites in GaN

    E-Print Network [OSTI]

    Nabben, Reinhard

    2006-01-01T23:59:59.000Z

    in GaN W. GehlhoffÃ, D. Azamat1 , U. Haboeck, A. Hoffmann Institute for Solid State Physics, Technical freestanding hydride vapor phase grown GaN have been studied in the X- and Q-band. A complex resonance pattern with C3v symmetry in the wurtzite structure of GaN. Aside from the displacement of their magnetic axis

  7. Superluminescence in Green Emission GaInN/GaN Quantum Well Structures under Pulsed Laser Excitation

    E-Print Network [OSTI]

    Wetzel, Christian M.

    and bulk GaN substrates, respectively. Under intense pulsed photo excitation, we observed strong the same excitation conditions, the blue shift for the m-axis grown structure on bulk GaN substrate is less-plane sapphire substrate and along the non-polar m-axis on m-plane bulk GaN substrate. The frequently used

  8. A SURVEY OF CIGUATERA AT ENEWETAK AND BIKINI, MARSHALL ISLANDS, WITH NOTES ON

    E-Print Network [OSTI]

    A SURVEY OF CIGUATERA AT ENEWETAK AND BIKINI, MARSHALL ISLANDS, WITH NOTES ON THE SYSTEMATICS ofpotentially ciguatoxicfishes from Enewetak and 256 specimens of 23 species from Bikini, Marshall Islands, were names was necessary for a few ofthe fishes. The Marshall Islands are the easternmost islands

  9. Can Microsatellites Be Used to Infer Phylogenies? Evidence from Population Affinities of the Western Canary Island

    E-Print Network [OSTI]

    Danchin, Etienne

    of the Western Canary Island Lizard (Gallotia galloti) Murielle Richard1 and Roger S. Thorpe2 School of the West- ern Canary Island lacertid (Gallotia galloti) as a model. The geological times of island in 12 populations from four islands (representing five haplotype lineages) was investigated in five

  10. Inferring dispersal: a Bayesian approach to phylogeny-based island biogeography,

    E-Print Network [OSTI]

    García-Barros, Enrique

    , with special reference to the Canary Islands Isabel Sanmarti´n1 *, Paul van der Mark2 and Fredrik Ronquist2,3 1 set of published phylogenies of Canary Island organisms to examine overall dispersal rates archipelagos with special reference to the Atlantic Canary Islands. Methods The Canary Islands were divided

  11. ORIGINAL PAPER The diet of feral cats on islands: a review and a call for more

    E-Print Network [OSTI]

    Zavaleta, Erika

    Santa Cruz de La Palma, Canary Islands, Spain M. Nogales Island Ecology and Evolution Research Group (IPNA-CSIC), Astrofi´sico Francisco Sa´nchez 3, 38206 La Laguna Tenerife, Canary Islands, Spain BORIGINAL PAPER The diet of feral cats on islands: a review and a call for more studies E. Bonnaud

  12. Are ightless Galapaganus weevils older than the Galapagos Islands they inhabit?

    E-Print Network [OSTI]

    Farrell, Brian D.

    are the Canary Islands (Thorpe et al., 1994; Juan et al., 1995, 1996) the Gala pagos Islands (Darwin, 1859Are ¯ightless Galapaganus weevils older than the GalaÂpagos Islands they inhabit? ANDREA S and include 10 ¯ightless species endemic to the Gala pagos islands. These beetles thus provide a promising

  13. Island biogeography Much of our current understanding of how many species occupy a community comes from

    E-Print Network [OSTI]

    Creel, Scott

    a balance between ongoing immigration of new species to the island and continuous extinction of species') and E is the maximum rate of extinction (the rate of extinction when the number of species on the island there are no species on the island (logically). But extinction rate increases with increasing species on the island

  14. Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography

    SciTech Connect (OSTI)

    Liu, Fang; Huang, Li; Davis, Robert F.; Porter, Lisa M.; Schreiber, Daniel K.; Kuchibhatla, S. V. N. T.; Shutthanandan, V.; Thevuthasan, Suntharampillai; Preble, Edward; Paskova, Tanya; Evans, K. R.

    2014-09-04T23:59:59.000Z

    In0.20Ga0.80N/GaN multi-quantum wells grown on [0001]-oriented GaN substrates with and without an InGaN buffer layer were characterized using three-dimensional atom probe tomography. In all samples, the upper interfaces of the QWs were slightly more diffuse than the lower interfaces. The buffer layers did not affect the roughness of the interfaces within the quantum well structure, a result attributed to planarization of the surface of the 1st GaN barrier layer which had an average root-mean-square roughness of 0.177 nm. The In and Ga distributions within the MQWs followed the expected distributions for a random alloy with no indications of In clustering.

  15. Point defect balance in epitaxial GaSb

    SciTech Connect (OSTI)

    Segercrantz, N., E-mail: natalie.segercrantz@aalto.fi; Slotte, J.; Makkonen, I.; Kujala, J.; Tuomisto, F. [Department of Applied Physics, Aalto University, P.O. Box 14100, FIN-00076 Aalto Espoo (Finland); Song, Y.; Wang, S. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Göteborg (Sweden); State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences 865 Changning Road, Shanghai 200050 (China)

    2014-08-25T23:59:59.000Z

    Positron annihilation spectroscopy in both conventional and coincidence Doppler broadening mode is used for studying the effect of growth conditions on the point defect balance in GaSb:Bi epitaxial layers grown by molecular beam epitaxy. Positron annihilation characteristics in GaSb are also calculated using density functional theory and compared to experimental results. We conclude that while the main positron trapping defect in bulk samples is the Ga antisite, the Ga vacancy is the most prominent trap in the samples grown by molecular beam epitaxy. The results suggest that the p–type conductivity is caused by different defects in GaSb grown with different methods.

  16. Office of Fossil Energy

    Office of Environmental Management (EM)

    GA 2.9 3.0 5.9 Everett, MA 7.7 7.6 15.4 Freeport, TX - - - Golden Pass, TX - - - Gulf LNG, MS - - - Lake Charles, LA - - - Neptune Deepwater Port - - - Northeast Gateway Energy...

  17. Room-temperature cw operation of InGaAsP/InGaP lasers at 727 nm grown on GaAs substrates by liquid phase epitaxy

    SciTech Connect (OSTI)

    Wakao, K.; Nishi, H.; Kusunoki, T.; Isozumi, S.; Ohsaka, S.

    1984-06-01T23:59:59.000Z

    InGaAsP/InGaP lasers emitting at 724--727 nm have been fabricated on GaAs substrates using liquid phase epitaxy. The threshold current is reduced to 8 kA/cm/sup 2/ by thinning the active layer. Room-temperature cw operation is achieved for the first time in the lasing wavelength range below 760 nm in this quaternary system.

  18. Self-assembled In0.5Ga0.5As quantum dots on GaP Yuncheng Song,a

    E-Print Network [OSTI]

    Haller, Gary L.

    SAQDs . Several groups have investigated the growth of both InP and In-rich InGaP SAQDs on GaP.7­12 Most temperature operation of vis- ible light emitting diodes LEDs using InP/GaP and InGaP/ GaP SAQDs, respectively

  19. Current crowding in GaInN / GaN LEDs grown on insulating substrates X. Guo, E. F. Schubert and J. Jahns

    E-Print Network [OSTI]

    Jahns, Jürgen

    Current crowding in GaInN / GaN LEDs grown on insulating substrates X. Guo, E. F. Schubert and J spreading in a mesa-structure GaN-based LED grown on an insulating or semi-insulating substrate. (b. Jahns Current crowding in mesa-structure GaInN/GaN light-emitting diodes (LEDs) grown on insulating

  20. Gas-source molecular beam epitaxial growth and characterization of the (Al,In,Ga)NP/GaP material system and Its applications to light-emitting diodes

    E-Print Network [OSTI]

    Odnoblyudov, Vladimir

    2006-01-01T23:59:59.000Z

    ? G, Kcal/mol GaP GaN AlN o Substrate temperature, C Figurenm-thick GaN 0.006 P 0.994 layer on substrate temperature.substrate temperature for Reactions formation of AlP, GaP, GaN and

  1. IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 2, FEBRUARY 2003 653 AlGaN/GaN HFET Power Amplifier Integrated With

    E-Print Network [OSTI]

    Itoh, Tatsuo

    the first demonstration of a GaN-based HFET was done on a sapphire substrate in 1993 [1]­[3]. This is due crystal quality compared to that of the sapphire substrate. Thanks to steadfast progress in AlGaN/GaN HFETIEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 2, FEBRUARY 2003 653 AlGaN/GaN

  2. Tunable THz plasmon resonances in InGaAs/InP HEMT R. E. Peale*a

    E-Print Network [OSTI]

    Peale, Robert E.

    , high ns, and small m*. A variety of materials systems such as GaAs/AlGaAs [3], InGaP/InGaAs/GaAs [4

  3. Prospective emission efficiency and in-plane light polarization of nonpolar m-plane InxGa1-xN/GaN blue light emitting diodes fabricated on freestanding GaN substrates

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    fabricated on freestanding GaN substrates T. Koyama and T.on freestanding m-plane GaN substrates. Although the ? inton the freestanding GaN substrate. cause the current was

  4. Reactive codoping of GaAlInP compound semiconductors

    DOE Patents [OSTI]

    Hanna, Mark Cooper (Boulder, CO); Reedy, Robert (Golden, CO)

    2008-02-12T23:59:59.000Z

    A GaAlInP compound semiconductor and a method of producing a GaAlInP compound semiconductor are provided. The apparatus and method comprises a GaAs crystal substrate in a metal organic vapor deposition reactor. Al, Ga, In vapors are prepared by thermally decomposing organometallic compounds. P vapors are prepared by thermally decomposing phospine gas, group II vapors are prepared by thermally decomposing an organometallic group IIA or IIB compound. Group VIB vapors are prepared by thermally decomposing a gaseous compound of group VIB. The Al, Ga, In, P, group II, and group VIB vapors grow a GaAlInP crystal doped with group IIA or IIB and group VIB elements on the substrate wherein the group IIA or IIB and a group VIB vapors produced a codoped GaAlInP compound semiconductor with a group IIA or IIB element serving as a p-type dopant having low group II atomic diffusion.

  5. Influence of Ga content on the structure and anomalous Hall effect of Fe{sub 1?x}Ga{sub x} thin films on GaSb(100)

    SciTech Connect (OSTI)

    Anh Tuan, Duong; Shin, Yooleemi; Viet Cuong, Tran; Cho, Sunglae, E-mail: slcho@ulsan.ac.kr [Department of Physics and Energy Harvest-Storage Research Center, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Phan, The-Long [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)

    2014-05-07T23:59:59.000Z

    The Fe{sub 1?x}Ga{sub x} thin films (x?=?0.4, 0.5) have been grown on GaSb(100) substrate using molecular beam epitaxy. An epitaxial film with bcc ?-Fe crystal structure (A2) is observed in Fe{sub 0.6}Ga{sub 0.4} film, while an impure Fe{sub 3}Ga phase with DO{sub 3} structure is appeared in Fe{sub 0.5}Ga{sub 0.5} film. The saturated magnetizations at room temperature are observed to be 570?emu/cm{sup 3} and 180?emu/cm{sup 3} and the coercivities to be 170 and 364?Oe for Fe{sub 0.6}Ga{sub 0.4} and Fe{sub 0.5}Ga{sub 0.5}, respectively. A hysteresis trend in Hall resistance vs. magnetic field is observed for Fe{sub 0.5}Ga{sub 0.5} film. However, there is a weak hysteresis noticed in Fe{sub 0.4}Ga{sub 0.6} thin film.

  6. Catastrophic degradation of InGaAsP/InGaP double-heterostructure lasers grown on (001) GaAs substrates by liquid-phase epitaxy

    SciTech Connect (OSTI)

    Ueda, O.; Wakao, K.; Komiya, S.; Yamaguchi, A.; Isozumi, S.; Umebu, I.

    1985-12-01T23:59:59.000Z

    Catastrophically degraded InGaAsP/InGaP double-heterostructure lasers grown on (001) GaAs substrates by liquid-phase epitaxy, emitting at 727 and 810 nm are investigated by photoluminescence topography, scanning electron microscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The degradation is mainly due to catastrophic optical damage at the facet, i.e., development of <110> dark-line defects from the facet, and rarely due to catastrophic optical damage at some defects, i.e., development of <110> dark-line defects from the defects inside the stripe region. These <110> dark-line defects correspond to complicated dislocation networks connected with dark knots, and are quite similar to those observed in catastrophically degraded GaAlAs/GaAs double-heterostructure lasers. The degradation characteristics of the InGaAsP/InGaP double-heterostructure lasers are rather similar to those in GaAlAs/GaAs double-heterostructure lasers concerning the catastrophic degradation.

  7. Dynamics of thermalization in GaInN/GaN quantum wells grown on ammonothermal GaN

    SciTech Connect (OSTI)

    Binder, J.; Korona, K. P.; Wysmo?ek, A.; Kami?ska, M. [Faculty of Physics, University of Warsaw, ul. Hoza 69, 00-681 Warsaw (Poland); Köhler, K.; Kirste, L.; Ambacher, O. [Fraunhofer Institute for Applied Solid State Physics, Tullastr. 72, 79108 Freiburg (Germany); Zaj?c, M.; Dwili?ski, R. [AMMONO SA, Czerwonego Krzy?a 2/31, 00-377 Warsaw (Poland)

    2013-12-14T23:59:59.000Z

    In this work, we present measurements of the dynamics of photoexcited carriers in GaInN/GaN quantum wells (QWs) grown on ammonothermal GaN, especially thermalization and recombination rates. Emission properties were measured by time-resolved photoluminescence (PL) and electroluminescence spectroscopy. Due to the use of high quality homoepitaxial material, we were able to obtain very valuable data on carrier thermalization. The temperature dependence of the QW energy observed in PL shows characteristic S-shape with a step of about 10?meV. Such a behavior (related to thermalization and localization at potential fluctuations) is often reported for QWs; but in our samples, the effect is smaller than in heteroepitaxial InGaN/GaN QWs due to lower potential fluctuation in our material. Absorption properties were studied by photocurrent spectroscopy measurements. A comparison of emission and absorption spectra revealed a shift in energy of about 60?meV. Contrary to PL, the QW energy observed in absorption decreases monotonically with temperature, which can be described by a Bose-like dependence E(T)?=?E(0) ? ?/(exp(?/T) ? 1), with parameters ??=?(0.11?±?0.01) eV, ??=?(355?±?20)?K, or by a Varshni dependence with coefficients ??=?(10?±?3) × 10{sup ?4}?eV/K and ??=?(1500?±?500) K. Taking into account absorption and emission, the fluctuation amplitude (according to Eliseev theory) was ??=?14?meV. The time resolved PL revealed that in a short period (<1?ns) after excitation, the PL peaks were broadened because of the thermal distribution of carriers. We interpreted this distribution in terms of quasi-temperature (T{sub q}) of the carriers. The initial T{sub q} was of the order of 500?K. The thermalization led to a fast decrease of T{sub q}. The obtained cooling time in the QW was ?{sub C}?=?0.3?ns, which was faster than the observed recombination time ?{sub R}?=?2.2?ns (at 4?K)

  8. assateague island national: Topics by E-print Network

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

    OF THE DEPARTMENT OF VERTEBRATE ZOOLOGY NATIONAL MUSEUM OF NATURAL surveys of the Marshall and Marianas Islands by L. P. Schultz and colleagues. Vic went on to exceed all...

  9. aeolian islands italy: Topics by E-print Network

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

    de 14 Natural Hazards and Earth System Sciences Tsunami generation in Stromboli island and impact on the CiteSeer Summary: Abstract. Stromboli is one of the most active...

  10. Power Plant Options Report for Thompson Island prepared by the

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Power Plant Options Report for Thompson Island A report prepared by the Renewable Energy Research....................................................................... 7 3. Grid-connected and Autonomous Renewable Power Systems ................................ 9 3.1. Renewable Power Sources .............................................................................. 9 3

  11. 46 Various stories from life on Hebert Island (part 1)

    E-Print Network [OSTI]

    Leonard, Stephen Pax

    last updated on Monday, 4 April 2011 Accession Form for Individual Recordings: Collection / Collector Name Stephen Leonard Tape No. / Track / Item No. 46 Length of track 1 hour 53 minutes Title of track Various stories from life on Hebert Island...

  12. 47 Various stories from life on Hebert Island (part 2)

    E-Print Network [OSTI]

    Leonard, Stephen Pax

    last updated on Monday, 4 April 2011 Accession Form for Individual Recordings: Collection / Collector Name Stephen Leonard Tape No. / Track / Item No. 48 Length of track 2 hour 2 minutes Title of track Various stories from life on Hebert Island...

  13. First Regional Super ESPC a Success on Kodiak Island, Alaska...

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

    at Kodiak Island helped pave the way for additional Super ESPC projects at other agencies. "For these projects to be successful, the agency needs to be committed at the site...

  14. Qualifying RPS Market States (Prince Edward Island, Canada)

    Broader source: Energy.gov [DOE]

    This entry lists the states with RPS policies that accept generation located in Prince Edward Island, Canada as eligible sources towards their Renewable Portfolio Standard targets or goals. For...

  15. Visual Modeling for Aqua Ventus I off Monhegan Island, ME

    SciTech Connect (OSTI)

    Hanna, Luke A.; Whiting, Jonathan M.; Copping, Andrea E.

    2013-11-27T23:59:59.000Z

    To assist the University of Maine in demonstrating a clear pathway to project completion, PNNL has developed visualization models of the Aqua Ventus I project that accurately depict the Aqua Ventus I turbines from various points on Monhegain Island, ME and the surrounding area. With a hub height of 100 meters, the Aqua Ventus I turbines are large and may be seen from many areas on Monhegan Island, potentially disrupting important viewsheds. By developing these visualization models, which consist of actual photographs taken from Monhegan Island and the surrounding area with the Aqua Ventus I turbines superimposed within each photograph, PNNL intends to support the project’s siting and permitting process by providing the Monhegan Island community and various other stakeholders with a probable glimpse of how the Aqua Ventus I project will appear.

  16. Rules and Regulations for Groundwater Quality (Rhode Island)

    Broader source: Energy.gov [DOE]

    These regulations provide standards for groundwater quality in the state of Rhode Island. The rules are intended to protect and restore the quality of the state's groundwater resources for use as...

  17. Quantitative analysis of forest island pattern in selected Ohio landscapes

    SciTech Connect (OSTI)

    Bowen, G.W.; Burgess, R.L.

    1981-07-01T23:59:59.000Z

    The purpose of this study was to quantitatively describe the various aspects of regional distribution patterns of forest islands and relate those patterns to other landscape features. Several maps showing the forest cover of various counties in Ohio were selected as representative examples of forest patterns to be quantified. Ten thousand hectare study areas (landscapes) were delineated on each map. A total of 15 landscapes representing a wide variety of forest island patterns was chosen. Data were converted into a series of continuous variables which contained information pertinent to the sizes, shape, numbers, and spacing of woodlots within a landscape. The continuous variables were used in a factor analysis to describe the variation among landscapes in terms of forest island pattern. The results showed that forest island patterns are related to topography and other environmental features correlated with topography.

  18. MIE Regional Climate Change Impact Webinar Series: Hawaii & Pacific Islands

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy's (DOE's) Minorities in Energy Initiative is hosting a webinar on Hawaii and Pacific Islands impacts of climate change on minority and tribal communities featuring...

  19. Rules and Regulations for Sewage Sludge Management (Rhode Island)

    Broader source: Energy.gov [DOE]

    The purpose of these rules and regulations is to ensure that sewage sludge that is treated, land applied, disposed, distributed, stockpiled or transported in the State of Rhode Island is done so in...

  20. THE UNIVERSITY OF RHODE ISLAND FRINGE BENEFIT AVERAGE RATE

    E-Print Network [OSTI]

    Rhode Island, University of

    THE UNIVERSITY OF RHODE ISLAND FRINGE BENEFIT AVERAGE RATE FY 2015 Allocation Cost or Classified.2% URI Budget & Financial Planning Office 9.17.14 Office:fringebenefits:office of sponsored projects: FY2015 Allocation #12;

  1. PSEG Long Island- Solar Initiative Feed-in Tariff

    Broader source: Energy.gov [DOE]

    The PSEG Long Island Feed-in Tariff II (FIT II) program provides fixed payments for electricity produced by approved photovoltaic systems over a fixed period of time. The program operates under a...

  2. Midwest Quantitative Biology Conference Mission Point Resort, Mackinac Island, Michigan

    E-Print Network [OSTI]

    Midwest Quantitative Biology Conference Mission Point Resort, Mackinac Island, Michigan September Exchange Method for the Free Energy of Conformational Fluctuations Michigan State University 3:05-3:30 Role

  3. Temporal Variation in Fish Communities Off Santa Cruz Island, California

    E-Print Network [OSTI]

    Larson, Ralph

    2008-01-01T23:59:59.000Z

    at sub-tidal reefs and kelp beds at Santa Cruz Island in theand/or by the loss of giant kelp, which occurs during warm-diminishing the extent of giant kelp beds. Student Michelle

  4. A Simple Technique for Islanding Detection with Negligible Nondetection Zone

    E-Print Network [OSTI]

    Kirtley Jr, James L.

    Although active islanding detection techniques have smaller nondetection zones than passive techniques, active methods could degrade the system power quality and are not as simple and easy to implement as passive methods. ...

  5. aegean island arc: Topics by E-print Network

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

    proposed that the maximum observed thickness Cai, Long 10 Geological Setting, Mineral Resources and ancient works of Samos and adjacent islands of the Aegean Sea, 26-30 August...

  6. Closing Event- Asian American and Pacific Islander Heritage Month

    Broader source: Energy.gov [DOE]

    Invited speakers from Congress, the federal government, and DOE will speak about Asian American and Pacific Islander programs and policy at the Department, and their contributions to the DOE...

  7. Asian American and Pacific Islander Heritage Month Program

    Broader source: Energy.gov [DOE]

    Asian Pacific American Heritage Month is a celebration of the culture, traditions, and history of Asian Americans and Pacific Islanders in the United States. Join the Energy Department for the...

  8. Town of Babylon- Long Island Green Homes Program

    Broader source: Energy.gov [DOE]

    The Long Island Green Homes Program is a self-financing residential retrofit program designed to support a goal of upgrading the energy efficiency of existing homes in the Town of Babylon. The...

  9. Long Island Power Authority- Residential Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Long Island Power Authority offers a variety of incentive programs which help residential customers upgrade to more energy efficient equipment and appliances in their homes. The Cool Homes Program...

  10. Demonstration of Black Liquor Gasification at Big Island

    SciTech Connect (OSTI)

    Robert DeCarrera

    2007-04-14T23:59:59.000Z

    This Final Technical Report provides an account of the project for the demonstration of Black Liquor Gasification at Georgia-Pacific LLC's Big Island, VA facility. This report covers the period from May 5, 2000 through November 30, 2006.

  11. A seaside resort in an island of the Aegean

    E-Print Network [OSTI]

    Kriezis, Constantine Anthony

    1988-01-01T23:59:59.000Z

    The purpose of the thesis is the design of a seaside resort in the island of Andros in Greece. A year-round focus of attraction amidst the Aegean Sea the resort would center around sea related activities. The experience ...

  12. Quaternary morphology and paleoenvironmental records of carbonate islands

    E-Print Network [OSTI]

    Toomey, Michael (Michael Ryan)

    2014-01-01T23:59:59.000Z

    Here I use a simple numerical model of reef profile evolution to show that the present-day morphology of carbonate islands has developed largely in response to late Pleistocene sea level oscillations in addition to variable ...

  13. Renewable Energy and Inter-Island Power Transmission (Presentation)

    SciTech Connect (OSTI)

    Gevorgian, V.

    2011-05-01T23:59:59.000Z

    This presentation summarizes recent findings pertaining to inter-island connection of renewable and other energy sources, in particular, as these findings relate cable options, routing, specifications, and pros and cons.

  14. Distribution, Growth, and Disturbance of Catalina Island Rhodoliths

    E-Print Network [OSTI]

    Tompkins, Paul Anthony

    2011-01-01T23:59:59.000Z

    seasonality. Sedimentology 41: 963-984 Friewald A (1998)Godinez-Orta L (2006) Sedimentology and acoustic mapping ofIsland, New Zealand. Sedimentology 55: 249-274 Orth RJ (

  15. Solar Water Heater Rebate Program (U.S. Virgin Islands)

    Broader source: Energy.gov [DOE]

    The Virgin Islands Energy Office currently offers rebates to residents for purchasing solar water heaters from local vendors. The program will cover residential, solar water heaters of 120 gallons...

  16. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    SciTech Connect (OSTI)

    None

    2013-09-01T23:59:59.000Z

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological and seawater samples from the marine and terrestrial environment of Amchitka Island adjacent to the three detonation sites and at a background or reference site, Adak Island, 180 miles to the east. Consistent with the goals of the Amchitka LTS&M Plan, four data quality objectives (DQOs) were developed for the 2011 sampling event.

  17. A wave refraction analysis for an axially symmetrical island

    E-Print Network [OSTI]

    Forst, Ronald John

    1966-01-01T23:59:59.000Z

    A WAVE REFRACTION ANALYSIS FOR AN AXIALLY SYMMETRICAL ISLAND A Thesis By LIEUTENANT RONALD J FORST UNITED STATES NAVY Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE l966 Major Subject Oceanography A WAVE REFRACTION ANALYSIS FOR AN AXIALLY SYMMETRICAL ISLAND A Thesis By LIEUTENANT RONALD J FORST UNITED STATES NAVY Approved as to style and content by; ( airma Committee) Head of Dep rtme t...

  18. Fish assemblages on coral reefs in Guanaja, Bay Islands, Honduras

    E-Print Network [OSTI]

    Mahendran, Christopher Kandiah

    1999-01-01T23:59:59.000Z

    FISH ASSEMBLAGES ON CORAL REEFS IN GUANAJA, BAY ISLANDS, HONDURAS A Thesis by CHRISTOPHER KANDIAH MAHENDRAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1999 Major Subject: Wildlife and Fisheries Sciences FISH ASSEMBLAGES ON CORAL REEFS IN GUANAJA, BAY ISLANDS, HONDURAS A Thesis by CHRISTOPHER KANDIAH MAHENDRAN Submitted to Texas A&M University in partial fulfillment...

  19. Aleutian Pribilof Islands Wind Energy Feasibility Study

    SciTech Connect (OSTI)

    Bruce A. Wright

    2012-03-27T23:59:59.000Z

    Under this project, the Aleutian Pribilof Islands Association (APIA) conducted wind feasibility studies for Adak, False Pass, Nikolski, Sand Point and St. George. The DOE funds were also be used to continue APIA's role as project coordinator, to expand the communication network quality between all participants and with other wind interest groups in the state and to provide continued education and training opportunities for regional participants. This DOE project began 09/01/2005. We completed the economic and technical feasibility studies for Adak. These were funded by the Alaska Energy Authority. Both wind and hydro appear to be viable renewable energy options for Adak. In False Pass the wind resource is generally good but the site has high turbulence. This would require special care with turbine selection and operations. False Pass may be more suitable for a tidal project. APIA is funded to complete a False Pass tidal feasibility study in 2012. Nikolski has superb potential for wind power development with Class 7 wind power density, moderate wind shear, bi-directional winds and low turbulence. APIA secured nearly $1M from the United States Department of Agriculture Rural Utilities Service Assistance to Rural Communities with Extremely High Energy Costs to install a 65kW wind turbine. The measured average power density and wind speed at Sand Point measured at 20m (66ft), are 424 W/m2 and 6.7 m/s (14.9 mph) respectively. Two 500kW Vestas turbines were installed and when fully integrated in 2012 are expected to provide a cost effective and clean source of electricity, reduce overall diesel fuel consumption estimated at 130,000 gallons/year and decrease air emissions associated with the consumption of diesel fuel. St. George Island has a Class 7 wind resource, which is superior for wind power development. The current strategy, led by Alaska Energy Authority, is to upgrade the St. George electrical distribution system and power plant. Avian studies in Nikolski and Sand Point have allowed for proper wind turbine siting without killing birds, especially endangered species and bald eagles. APIA continues coordinating and looking for funding opportunities for regional renewable energy projects. An important goal for APIA has been, and will continue to be, to involve community members with renewable energy projects and energy conservation efforts.

  20. Manipulation of emission energy in GaAs/AlGaAs core-shell nanowires with radial heterostructure

    SciTech Connect (OSTI)

    Barbosa, B. G.; Arakaki, H.; Souza, C. A. de; Pusep, Yu. A. [Instituto de Fisica de São Carlos, Universidade de São Paulo, 13560-970 Sao Carlos, SP (Brazil)

    2014-03-21T23:59:59.000Z

    Photoluminescence was studied in GaAs/AlGaAs nanowires (NWs) with different radial heterostructures. We demonstrated that manipulation of the emission energy may be achieved by appropriate choice of the shell structure. The emission at highest energy is generated in the NWs with tunneling thin AlGaAs inner shell and thin GaAs outer shell due to recombination of the photoexcited electrons confined in the outer shell with the holes in the core. Lower energy emission was shown to occur in the NWs with thick outer shell grown in the form of a short-period GaAs/AlGaAs multiple quantum well structure. In this case, the tunneling probability through the multiple quantum wells controls the energy emitted by the NWs. The doping of core results in dominated low energy emission from the GaAs core.