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Sample records for ga proposed action

  1. Environmental Assessment - Proposed Actions

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

    availability of Waste Isolation Pilot Plant (WIPP) facilities and infrastructure to scientists who wish to conduct experiments there. DOE would allow these experiments if they can be conducted without interfering with the WIPP's primary transuranic waste disposal mission and if they reflect contemporary budget priorities. This fact sheet presents questions and answers about the proposed action and its alternative. The deep geologic repository at the WIPP could provide a favorable environment for

  2. Categorical Exclusion Determination Form Proposed Action Title...

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

    Proposed Action Title: (0473-1597) Smart Wire Grid, Inc. - Distributed Power Flow Contro l Using Smart Wires for Energy Routing Program or Field Office: Advanced Research Projects ...

  3. Implementation Proposal for the National Action Plan on Demand...

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

    Implementation Proposal for the National Action Plan on DemandResponse - July 2011 Implementation Proposal for the National Action Plan on Demand Response - July 2011 Report to ...

  4. N Springs expedited response action proposal

    SciTech Connect (OSTI)

    Not Available

    1994-01-01

    Since signing the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) in 1989, the parties to the agreement have recognized the need to modify the approach to conducting investigations, studies, and cleanup actions at Hanford. To implement this approach, the parties have jointly developed the Hanford Past-Practice Strategy. The strategy defines a non-time-critical expedited response action (ERA) as a response action ``needed to abate a threat to human health or welfare or the environment where sufficient time exists for formal planning prior to initiation of response. In accordance with the past-practice strategy, DOE proposes to conduct an ERA at the N Springs, located in the Hanford 100 N Area, to substantially reduce the strontium-90 transport into the river through the groundwater pathway. The purpose of this ERA proposal is to provide sufficient information to select a preferred alternative at N Springs. The nature of an ERA requires that alternatives developed for the ERA be field ready; therefore, all the technologies proposed for the ERA should be capable of addressing the circumstances at N Springs. A comparison of these alternatives is made based on protectiveness, cost, technical feasibility, and institutional considerations to arrive at a preferred alternative. Following the selection of an alternative, a design phase will be conducted; the design phase will include a detailed look at design parameters, performance specifications, and costs of the selected alternative. Testing will be conducted as required to generate design data.

  5. Chapter 2 - Proposed Action and Alternatives

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

    Chapter 19 - Small Business Programs Chapter 19 - Small Business Programs 19_Small Business Programs_0.pdf (311.5 KB) AG19 1.pdf (29.07 KB) Department of Energy Partnership Agreement.pdf (3.21 MB) More Documents & Publications Acquisition Guide Chapter 19 Update OPAM Policy Acquisition Guides Guidance of the Department of Energy Subcontracting Program

    2-1 CHAPTER 2 PROPOSED ACTION AND ALTERNATIVES The WIPP facility, in addition to serving its primary mission as a TRU waste disposal site,

  6. ACTION DESCRIPTION MEMORANDUM PROPOSED DECONTAMINATION OF THREE...

    Office of Legacy Management (LM)

    ... of about 400 ha (1000 acres) and is a residential community of more than 45,000 people, ... As part of FUSRAP, the U.S. Department of Energy, Oak Ridge Operations, is proposing to ...

  7. CATEGORICAL EXCLUSION (CX) DETERMINATION BRIEF DESCRIPTION OF PROPOSED ACTION:

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

    'u ", lt~Fs::::N CATEGORICAL EXCLUSION (CX) DETERMINATION BRIEF DESCRIPTION OF PROPOSED ACTION: Southwestern Power Administration proposes to construct a maintenance garage for heavy vehicles and equipment at the Springfield, Missouri facility. PROPOSED BY: Southwestern Power Administration- U.S. Dept. of Energy DATE: December 7,2010 NUMBERS AND TITLES OF THE CATEGORICAL EXCLUSIONS BEING APPLIED: 10 CFR 1021, Appendix B to Subpart D, Part B1.15- Siting, construction or modification of

  8. CATEGORICAL EXCLUSION (CX) DETERMINATION BRIEF DESCRIPTION OF PROPOSED ACTION:

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

    CATEGORICAL EXCLUSION (CX) DETERMINATION BRIEF DESCRIPTION OF PROPOSED ACTION: Southwestern Power Administration (Southwestern) proposes to obtain an easement for an existing access road which is located in Carroll County, Arkansas. The easement will serve to facilitate Southwestern's electrical utility vehicles accessing electrical transmission line 3008, near structure 33, in Carroll County, Arkansas. PROPOSED BY: Southwestern Power Administration- U.S. Dept. of Energy DATE: January 28,2011

  9. The NEPA threshold question revisited: Proposed'' actions and continuing'' activities

    SciTech Connect (OSTI)

    Wolff, T.A. ); Hansen, R.P. )

    1993-01-01

    The National Environmental Policy Act (NEPA) requires Federal agencies to include a detailed statement'' in every recommendation or report on proposals'' for major Federal actions significantly affecting the quality of the human environment.'' Unless the three elements of a proposal are present (major, federal, and action), preparation of a detailed statement is not required. This paper addresses the practical decision-making dilemma that attends determinations of what types of Federal activities meet the NEPA threshold test under what kinds of varying circumstances. The authors' experience with the US Dept. of Energy (DOE) NEPA documentation is used to discuss how decisions may be made to determine whether a proposed action qualifies for a categorical exclusion'' or whether it requires preparation of an environmental assessment (EA) or an environmental impact statement (EIS). The concept of new'' actions versus continuing'' actions which may be bounded'' by previous NEPA documentation is also discussed. A dichotomous key for separating or combining Federal action'' candidates for different levels of NEPA documentation is provided. Leading court opinions on the threshold question and related issues are discussed in lay terms.

  10. CEQ Guidance on the Application of NEPA to Proposed Federal Actions...

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

    States with Transboundary Effects CEQ Guidance on the Application of NEPA to Proposed Federal Actions in the United States with Transboundary Effects CEQ Guidance on the ...

  11. Lasing action and extraordinary reduction in long radiative lifetime of type-II GaSb/GaAs quantum dots using circular photonic crystal nanocavity

    SciTech Connect (OSTI)

    Hsu, Kung-Shu; Chang, Shu-Wei; Hung, Wei-Chun; Chang, Chih-Chi; Lin, Wei-Hsun; Lin, Shih-Yen; Shih, Min-Hsiung; Lee, Po-Tsung; Chang, Yia-Chung

    2015-08-31

    We demonstrated the lasing action and remarkable reduction in long radiative lifetimes of type-II GaSb/GaAs quantum dots using a circular photonic-crystal nano-cavity with high Purcell factors. The associated enhancement in carrier recombination was surprisingly high and could even surpass type-I counterparts in similar conditions. These phenomena reveal that the type-II sample exhibited extremely low nonradiative recombination so that weak radiative transitions were more dominant than expected. The results indicate that type-II nanostructures may be advantageous for applications which require controllable radiative transitions but low nonradiative depletions.

  12. Title 40 CFR 1502.14 Alternatives Including the Proposed Action...

    Open Energy Info (EERE)

    .14 Alternatives Including the Proposed Action Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- Federal RegulationFederal Regulation: Title 40 CFR...

  13. Chromium Project Notice of Proposed Floodplain Action Public Comment Period Closes November 20th,

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

    Chromium Project Notice of Proposed Floodplain Action Public Comment Period Closes November 20th, 2015 The Department of Energy Environmental Management Los Alamos Field Office has prepared a Draft Environmental Assessment for the Chromium Plume Control Interim Measure and Plume-Center Characterization at the Los Alamos National Laboratory (LANL). The proposed action may include well pad and access road installation and maintenance, piezometer placement, and pipeline placement in the 100-year

  14. Categorical Exclusion Determination Form Proposed Action Title: (0474-1528) Ideal Power Converters Inc. -

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

    nt n rgy *Submitby£-mail Categorical Exclusion Determination Form Proposed Action Title: (0474-1528) Ideal Power Converters Inc. - Dual Bi-Directional Silicon IGBTs Modules Enables Breakthrough PV Inverter Using Current-Modulation Topology Program or Field Office: Advanced Research Projects Agency - Energy LocationCs) CCitY/County/State): California, New York, Virginia, Texas Proposed Action Description: Funding will support development of a low-cost, high-efficiency 100 kW power inverter to

  15. Proposed Action Title: U.S. Department of Energy Southwestern Power Administration

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

    Storm Shelter Construction Project Program or Field Office: Southwestern Power Administration Location(s) (City/County/State): Gore/Muskogee/Oklahoma; Jonesboro/Craighead/ Arkansas SWPAF 450.4 (Rev. 05/14) Proposed Action Description: Southwestern Power Administration proposes to construct aboveground storm shelters at at the Gore and Jonesboro Maintenance Facilities. Categorical Exclusion(s) Applied: 10 CFR 1021, Appendix 8 to Subpart D, Part 82.3. Installation of, or improvements to, equipment

  16. Proposed Action Title: U.S. Department of Energy Southwestern Power Administration

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

    Transmission Line Segment Modification, Line 3004, Structures 39, 39A, and 40 Program or Field Office: Southwestern Power Administration Location(s) (City/County/State): Springfield, Christian County, Missouri SWPA F450.4 (Rev. 2/16) Proposed Action Description: Southwestern Power Administration proposes to modify and relocate a small seqment of transmission line to accommodate and provide safety clearance for a retail development project in an urbanized section of Springfield, Missouri.

  17. Appliance Standard Program - The FY 2003 Priority -Setting Summary Report and Actions Proposed

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

    Appliance Standards Program The FY 2003 Priority- Setting Summary Report and Actions Proposed Date: August 22, 2002 Table of Contents i EXECUTIVE SUMMARY.............................................................................................. iv 1 Energy Conservation Program - Product Prioritization Process.......1-1 1.1 Background on Appliance Standards Program........................................... 1-1 1.2 DOE Authority to Add Products

  18. Proposed decision document, other contamination sources, interim response action, South Tank Farm Plume

    SciTech Connect (OSTI)

    Not Available

    1990-08-23

    The South Tank Farm Plume (STFP) is listed under the 'Remediation of Other Contamination Sources' Interim Response Action (IRA) sites under the Final Technical Program Plan FY88-FY92 and the Federal Facility Agreement. The process and guidelines used to assess alternatives, produce this Proposed Decision Document, and implement this IRA are specified in and conducted in accordance with the Federal Facility Agreement. The purposes of the Proposed Decision Document for Other Contamination Sources IRAs are to: (a) state the objective of the IRA; (b) discuss Interim Response Action alternatives, if any, that were considered; (c) provide the rationale for the alternative selected; (d) present the final ARAR decision; (e) summarize the significant comments received regarding the IRA and responses to those comments; and (f) establish an IRA Deadline for completion of the IRA, if appropriate. Each of the above mentioned issues is addressed in this document.

  19. Environmental Assessment for Conducting Astrophysics and Other Basic Science Experiments - Chapter 2 Proposed Action and Alternatives

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

    2-1 CHAPTER 2 PROPOSED ACTION AND ALTERNATIVES Some types of experiments are best (or only) performed deep underground. For this reason, scientists have considered WIPP as a potential site for these types of experiments and have sought permission from DOE to conduct several types of experiments there. As an example, astrophysicists are searching for very small particles with no charge called neutrinos. These particles are so small that they typically pass through the Earth. The only way to

  20. Operable Unit 3: Proposed Plan/Environmental Assessment for interim remedial action

    SciTech Connect (OSTI)

    Not Available

    1993-12-01

    This document presents a Proposed Plan and an Environmental Assessment for an interim remedial action to be undertaken by the US Department of Energy (DOE) within Operable Unit 3 (OU3) at the Fernald Environmental Management Project (FEMP). This proposed plan provides site background information, describes the remedial alternatives being considered, presents a comparative evaluation of the alternatives and a rationnale for the identification of DOE`s preferred alternative, evaluates the potential environmental and public health effects associated with the alternatives, and outlines the public`s role in helping DOE and the EPA to make the final decision on a remedy.

  1. Proposed measurement of spin currents in a GaAs crystal using the electro-optical Pockels effect

    SciTech Connect (OSTI)

    Zhang, Xingchu; Zheng, Yongjun; She, Weilong

    2014-07-14

    A new method for measuring spin currents is proposed, based on the linear electro-optic (Pockels) effect caused by the additional second-order nonlinear electric susceptibility (electro-optic tensor) generated by the spin currents. The non-zero elements of electro-optic tensor induced by spin currents in GaAs crystal are calculated, and the wave coupling theory of linear electro-optic effect is used to analyze the polarization change of a probe beam. The numerical results show that, for a linearly polarized probe beam with a frequency close to the band gap of GaAs crystal, its polarization rotation can be as large as 14 μrad under an applied electric field of about 350 V/mm. This effect should offer an alternative detection method for spintronics.

  2. DOE and FERC Jointly Submit Implementation Proposal for The National Action Plan on Demand Response to Congress

    Office of Energy Efficiency and Renewable Energy (EERE)

    The U.S. Department of Energy and the Federal Energy Regulatory Commission (FERC) jointly submitted to Congress a required “Implementation Proposal for The National Action Plan on Demand Response.”

  3. Site Rehabilitation Completion Report with No Further Action Proposal for the Northeast Site

    SciTech Connect (OSTI)

    Daniel, Joe; Tabor, Charles; Survochak, Scott

    2013-05-01

    The purpose of this Site Rehabilitation Completion Report is to present the post-active-remediation monitoring results for the Northeast Site and to propose No Further Action with Controls. This document includes information required by Chapter 62-780.750(4)(d), 62-780.750(6), and 62-780.600(8)(a)27 Florida Administrative Code (F.A.C.). The Closure Monitoring Plan for the Northeast Site and 4.5 Acre Site (DOE 2009a) describes the approach for post-active-remediation monitoring. The Young - Rainey Science, Technology, and Research Center (STAR Center) is a former U.S. Department of Energy (DOE) facility constructed in the mid-1950s. The 99-acre STAR Center is located in Largo, Florida. The Northeast Site is located in the northeast corner of the STAR Center. The Northeast Site meets all the requirements for an RMO II closure—No Further Action with Controls. DOE is nearing completion of a restrictive covenant for the Northeast Site. DOE has completed post-active-remediation monitoring at the Northeast Site as of September 2012. No additional monitoring will be conducted.

  4. Proposals

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

    Proposals Sign In About | Careers | Contact | Investors | bpa.gov Search Doing Business Expand Doing Business Customer Involvement Expand Customer Involvement Reports & Tools...

  5. Finding of no significant impact proposed corrective action for the Northeast Site at the Pinellas Plant in Largo, Florida

    SciTech Connect (OSTI)

    1995-06-01

    The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA) (DOE/EA-0976) of the proposed corrective action for the Northeast Site at the Pinellas Plant in Largo, Florida. The Northeast Site contains contaminated groundwater that would be removed, treated, and discharged to the Pinellas County Sewer System. Based on the analyses in the EA, the DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act of 1969 (NEPA), 42 U.S.C.4321 et.seq. Therefore, the preparation of an environmental impact statement is not required and the DOE is issuing this Finding of No Significant Impact (FONSI).

  6. Proposed

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

    Proposed Settlement for Hanford Cleanup U.S. Department of Energy ● Washington State Department of Ecology * U.S. Environmental Protection Agency What's this proposed settlement about? Public Comment The Tri-Party Agreement agencies want your feedback. The public comment period is from October 1 through December 11, 2009. These new commitments would address important activities that are needed to protect human health and the environment. The settlement will impose a new, enforceable and

  7. Guidance on the Application of NEPA to Proposed Federal Actions in the United States with Transboundary Effects (CEQ, 1997)

    Broader source: Energy.gov [DOE]

    The purpose of this guidance is to clarify the applicability of the National Environmental Policy Act (NEPA) to proposed federal actions in the United States, including its territories and possessions, that may have transboundary effects extending across the border and affecting another country's environment. While the guidance arises in the context of negotiations undertaken with the governments of Mexico and Canada to develop an agreement on transboundary environmental impact assessment in North America, the guidance pertains to all federal agency actions that are normally subject to NEPA, whether covered by an international agreement or not.

  8. CEQ Guidance on the Application of NEPA to Proposed Federal Actions in the United States with Transboundary Effects

    Broader source: Energy.gov [DOE]

    The purpose of this guidance is to clarify the applicability of the National Environmental Policy Act (NEPA) to proposed federal actions in the United States, including its territories and possessions, that may have transboundary effects extending across the border and affecting another country's environment. While the guidance arises in the context of negotiations undertaken with the governments of Mexico and Canada to develop an agreement on transboundary environmental impact assessment in North America, the guidance pertains to all federal agency actions that are normally subject to NEPA, whether covered by an international agreement or not.

  9. Review and analysis of proposed EPA groundwater standards for the UMTRA Project. [Uranium Mill Tailings Remedial Action (UMTRA) Project

    SciTech Connect (OSTI)

    Not Available

    1987-10-01

    The Title I groundwater standards for inactive uranium mill tailings sites, which were promulgated on January 5, 1983, by the US Environmental Protection Agency (EPA) for the Uranium Mill Tailings Remedial Action (UMTRA) Project, were remanded to the EPA on September 3, 1985, by the US Tenth Circuit Court of Appeals. The Court instructed the EPA to compile general groundwater standards for all sites. On September 24, 1987, the EPA published proposed standards in response to the remand. This Summary Report includes an evaluation of the potential effects of the proposed EPA groundwater standards on the UMTRA Project as well as a discussion of the DOE's position on the proposed standards. This report is accompanied by a detailed Technical Report and Appendices which provide supporting information and analyses. This Summary Report results from a study undertaken to: determine the impact of the proposed standards on the UMTRA Project; and recommend provisions for the implementation of the final standards that will minimize adverse impact to the conduct of the UMTRA Project while ensuring protection of human health and the environment. Specifically, the following were considered: the flexibility of the proposed standards; interpretations of the proposed standards; the extent of aquifer restoration that may be required to implement the proposed standards at each site; the costs of aquifer restoration; and design changes necessary to meet the standards.

  10. US Department of Energy response to standards for remedial actions at inactive uranium processing sites: Proposed rule

    SciTech Connect (OSTI)

    Not Available

    1988-01-29

    The Title I groundwater standards for inactive uranium mill tailings sites, which were promulgated on January 5, 1983, by the US Environmental Protection Agency (EPA) for the Uranium Mill Tailings Remedial Action (UMTRA) Project, were remanded to the EPA on September 3, 1985, by the US Tenth Circuit Court of Appeals. The Court instructed the EPA to compile general groundwater standards for all Title I sites. On September 24, 1987, the EPA published proposed standards (52FR36000-36008) in response to the remand. This report includes an evaluation of the potential effects of the proposed EPA groundwater standards on the UMTRA Project, as well as a discussion of the DOE's position on the proposed standards. The report also contains and appendix which provides supporting information and cost analyses. In order to assess the impacts of the proposed EPA standards, this report summarizes the proposed EPA standards in Section 2.0. The next three sections assess the impacts of the three parts of the EPA standards: Subpart A considers disposal sites; Subpart B is concerned with restoration at processing sites; and Subpart C addresses supplemental standards. Section 6.0 integrates previous sections into a recommendations section. Section 7.0 contains the DOE response to questions posed by the EPA in the preamble to the proposed standards. 6 refs., 5 figs., 3 tabs.

  11. Description of Proposed Action

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

    contained within the WIPP Land Withdrawal Area as part of ... petroleumnatural gas products that pre-exist in ... the other regulatory requirements set forth above are ...

  12. Proposed mechanism to represent the suppression of dark current density by four orders with low energy light ion (H{sup ?}) implantation in quaternary alloy-capped InAs/GaAs quantum dot infrared photodetectors

    SciTech Connect (OSTI)

    Mandal, A.; Ghadi, H.; Mathur, K.L.; Basu, A.; Subrahmanyam, N.B.V.; Singh, P.; Chakrabarti, S.

    2013-08-01

    Graphical abstract: - Abstract: Here we propose a carrier transport mechanism for low energy H{sup ?} ions implanted InAs/GaAs quantum dot infrared photodetectors supportive of the experimental results obtained. Dark current density suppression of up to four orders was observed in the implanted quantum dot infrared photodetectors, which further demonstrates that they are effectively operational. We concentrated on determining how defect-related material and structural changes attributed to implantation helped in dark current density reduction for InAs/GaAs quantum dot infrared photodetectors. This is the first study to report the electrical carrier transport mechanism of H{sup ?} ion-implanted InAs/GaAs quantum dot infrared photodetectors.

  13. Proposed plan for remedial action for the Groundwater Operable Unit at the Chemical Plant Area of the Weldon Spring Site, Weldon Spring, Missouri

    SciTech Connect (OSTI)

    1999-08-10

    This Proposed Plan addresses the remediation of groundwater contamination at the chemical plant area of the Weldon Spring site in Weldon Spring, Missouri. The site is located approximately 48 km (30 mi) west of St. Louis in St. Charles County . Remedial activities at the site will be conducted in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The U.S. Department of Energy (DOE), in conjunction with the U.S. Department of the Army (DA), conducted a joint remedial investigation/feasibility study (RI/FS) to allow for a comprehensive evaluation of groundwater conditions at the Weldon Spring chemical plant area and the Weldon Spring ordnance works area, which is an Army site adjacent to the chemical plant area. Consistent with DOE policy, National Environmental Policy Act (NEPA) values have been incorporated into the CERCLA process. That is, the analysis conducted and presented in the RVFS reports included an evaluation of environmental impacts that is comparable to that performed under NEPA. This Proposed Plan summarizes information about chemical plant area groundwater that is presented in the following documents: (1) The Remedial Investigation (RI), which presents information on the nature and extent of contamination; (2) The Baseline Risk Assessment (BRA), which evaluates impacts to human health and the environment that could occur if no cleanup action of the groundwater were taken (DOE and DA 1997a); and (3) The Feasibility Study (FS) and the Supplemental FS, which develop and evaluate remedial action alternatives for groundwater remediation.

  14. Environmental Assessment for the proposed modification and continued operation of the DIII-D facility

    SciTech Connect (OSTI)

    NONE

    1995-07-01

    The EA evaluates the proposed action of modifying the DIII-D fusion facility and conducting related research activities at the GA San Diego site over 1995-1999 under DOE contract number DE-ACO3-89ER51114. The proposed action is need to advance magnetic fusion research for future generation fusion devices such as ITER and TPX. It was determined that the proposed action is not a major action significantly affecting the quality of the human environment according to NEPA; therefore a finding of no significant impact is made and an environmental impact statement is not required.

  15. Proposal of high efficiency solar cells with closely stacked InAs/In{sub 0.48}Ga{sub 0.52}P quantum dot superlattices: Analysis of polarized absorption characteristics via intermediateband

    SciTech Connect (OSTI)

    Yoshikawa, H. Kotani, T.; Kuzumoto, Y.; Izumi, M.; Tomomura, Y.; Hamaguchi, C.

    2014-07-07

    We present a theoretical study of the electronic structures and polarized absorption properties of quantum dot superlattices (QDSLs) using widegap matrix material, InAs/In{sub 0.48}Ga{sub 0.52}P QDSLs, for realizing intermediateband solar cells (IBSCs) with twostep photonabsorption. The planewave expanded BurtForeman operator ordered 8band kp theory is used for this calculation, where strain effect and piezoelectric effect are taken into account. We find that the absorption spectra of the second transitions of twostep photonabsorption can be shifted to higher energy region by using In{sub 0.48}Ga{sub 0.52}P, which is latticematched material to GaAs substrate, as a matrix material instead of GaAs. We also find that the transverse magnetic polarized absorption spectra in InAs/In{sub 0.48}Ga{sub 0.52}P QDSL with a separate IB from the rest of the conduction minibands can be shifted to higher energy region by decreasing the QD height. As a result, the second transitions of twostep photonabsorption by the sunlight occur efficiently. These results indicate that InAs/In{sub 0.48}Ga{sub 0.52}P QDSLs are suitable material combination of IBSCs toward the realization of ultrahigh efficiency solar cells.

  16. Notice_of_Proposed_Action.pdf

    Office of Legacy Management (LM)

  17. EA-2005: Notice of Proposed Floodplain Action

    Broader source: Energy.gov [DOE]

    Chromium Plume Control Interim Measure and Plume-Center Characterization, Los Alamos National Laboratory, Los Alamos, NM

  18. A hole modulator for InGaN/GaN light-emitting diodes

    SciTech Connect (OSTI)

    Zhang, Zi-Hui; Kyaw, Zabu; Liu, Wei; Ji, Yun; Wang, Liancheng; Tan, Swee Tiam; Sun, Xiao Wei E-mail: VOLKAN@stanfordalumni.org; Demir, Hilmi Volkan E-mail: VOLKAN@stanfordalumni.org

    2015-02-09

    The low p-type doping efficiency of the p-GaN layer has severely limited the performance of InGaN/GaN light-emitting diodes (LEDs) due to the ineffective hole injection into the InGaN/GaN multiple quantum well (MQW) active region. The essence of improving the hole injection efficiency is to increase the hole concentration in the p-GaN layer. Therefore, in this work, we have proposed a hole modulator and studied it both theoretically and experimentally. In the hole modulator, the holes in a remote p-type doped layer are depleted by the built-in electric field and stored in the p-GaN layer. By this means, the overall hole concentration in the p-GaN layer can be enhanced. Furthermore, the hole modulator is adopted in the InGaN/GaN LEDs, which reduces the effective valance band barrier height for the p-type electron blocking layer from ?332?meV to ?294?meV at 80?A/cm{sup 2} and demonstrates an improved optical performance, thanks to the increased hole concentration in the p-GaN layer and thus the improved hole injection into the MQWs.

  19. Proposed Rules Federal Register

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

    5383 Vol. 81, No. 21 Tuesday, February 2, 2016 DEPARTMENT OF ENERGY 10 CFR Part 900 RIN 1901-AB36 Coordination of Federal Authorizations for Electric Transmission Facilities AGENCY: Office of Electricity Delivery and Energy Reliability, Department of Energy. ACTION: Notice of proposed rulemaking. SUMMARY: The Department of Energy (DOE) proposes to amend its regulations for the timely coordination of Federal Authorizations for proposed interstate electric transmission facilities pursuant to

  20. Enhanced thermoelectric transport in modulation-doped GaN/AlGaN core/shell nanowires

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

    Song, Erdong; Li, Qiming; Swartzentruber, Brian; Pan, Wei; Wang, George T.; Martinez, Julio A.

    2015-11-25

    The thermoelectric properties of unintentionally n-doped core GaN/AlGaN core/shell N-face nanowires are reported. We found that the temperature dependence of the electrical conductivity is consistent with thermally activated carriers with two distinctive donor energies. The Seebeck coefficient of GaN/AlGaN nanowires is more than twice as large as that for the GaN nanowires alone. However, an outer layer of GaN deposited onto the GaN/AlGaN core/shell nanowires decreases the Seebeck coefficient at room temperature, while the temperature dependence of the electrical conductivity remains the same. We attribute these observations to the formation of an electron gas channel within the heavily-doped GaN coremore » of the GaN/AlGaN nanowires. The room-temperature thermoelectric power factor for the GaN/AlGaN nanowires can be four times higher than the GaN nanowires. As a result, selective doping in bandgap engineered core/shell nanowires is proposed for enhancing the thermoelectric power.« less

  1. Enhanced thermoelectric transport in modulation-doped GaN/AlGaN core/shell nanowires

    SciTech Connect (OSTI)

    Song, Erdong; Li, Qiming; Swartzentruber, Brian; Pan, Wei; Wang, George T.; Martinez, Julio A.

    2015-11-25

    The thermoelectric properties of unintentionally n-doped core GaN/AlGaN core/shell N-face nanowires are reported. We found that the temperature dependence of the electrical conductivity is consistent with thermally activated carriers with two distinctive donor energies. The Seebeck coefficient of GaN/AlGaN nanowires is more than twice as large as that for the GaN nanowires alone. However, an outer layer of GaN deposited onto the GaN/AlGaN core/shell nanowires decreases the Seebeck coefficient at room temperature, while the temperature dependence of the electrical conductivity remains the same. We attribute these observations to the formation of an electron gas channel within the heavily-doped GaN core of the GaN/AlGaN nanowires. The room-temperature thermoelectric power factor for the GaN/AlGaN nanowires can be four times higher than the GaN nanowires. As a result, selective doping in bandgap engineered core/shell nanowires is proposed for enhancing the thermoelectric power.

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

    SciTech Connect (OSTI)

    Tsai, J.-H. Chiu, S.-Y.; Lour, W.-S.; Guo, D.-F.

    2009-07-15

    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.

  3. RAPIDD Proposals

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

    by ALS management, appropriate to the proposal. Rapid Access Proposals (RA) A proportion of beam time on some beamlines is reserved to provide rapid access for simple,...

  4. Action Items

    Office of Environmental Management (EM)

    ACTION ITEMS Presentation to the DOE High Level Waste Corporate Board July 29, 2009 Kurt Gerdes Office of Waste Processing DOE-EM Office of Engineering & Technology 2 ACTION ITEMS...

  5. ACTION PLAN

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

    -1 ACTION PLAN 1.0 INTRODUCTION 1.1 PURPOSE The purpose of this action plan is to establish the overall plan for hazardous waste permitting, meeting closure and postclosure requirements, and remedial action under the Federal Resource Conservation and Recovery Act (RCRA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and the Washington State Hazardous Waste Management Act. All actions required to be taken pursuant to this Agreement shall be taken in accordance

  6. RAPIDD Proposals

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

    RAPIDD Proposals RAPIDD Proposals Print Tuesday, 21 August 2012 14:41 The combined process for Rapid Access Proposals, Industry, and Director's Discretion (RAPIDD) beam time accommodates users who require limited or rapid access to ALS beam time. There are a number of proposal types that are available on a variety of beamlines, as described below. Log in to ALSHub to submit a RAPIDD proposal. The RAPIDD process is not suitable for users requiring significant beam time for an extended program of

  7. Notes and Action Items

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

    Notes and Action Items Notes and Action Items ERSUG Action Items from June 1996 meeting at Germantown, MD Get DOE staff on mailers for broadcast of ERSUG issues Responsibility: Kendall and Kitchens Review and comment on ERSUG Proposal to SAC Responsibility: All of ERSUG Comments to Rick Kendall by July 17th email: ra_kendall@pnl.gov Fax : (509) 375-6631 Review and comment on Requirements Document "Greenbook" Responsibility: All of ERSUG Comments to Rick Kendall by August 7th email:

  8. RAPIDD Proposals

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

    RAPIDD Proposals Print The combined process for Rapid Access Proposals, Industry, and Director's Discretion (RAPIDD) beam time accommodates users who require limited or rapid access to ALS beam time. There are a number of proposal types that are available on a variety of beamlines, as described below. Log in to ALSHub to submit a RAPIDD proposal. The RAPIDD process is not suitable for users requiring significant beam time for an extended program of research or those wanting to perform complex

  9. EIS-0476: Vogtle Electric Generating Plant in Burke County, GA | Department

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

    of Energy 6: Vogtle Electric Generating Plant in Burke County, GA EIS-0476: Vogtle Electric Generating Plant in Burke County, GA February 8, 2012 EIS-0476: Final Environmental Impact Statement Department of Energy Loan Guarantees for Proposed Units 3 and 4 at the Vogtle Electric Generating Plant, Burke County, GA February 25, 2014 EIS-0476: Record of Decision Department of Energy Loan Guarantees for Proposed Units 3 and 4 at the Vogtle Electric Generating Plant, Burke County, GA

  10. United States Forest Service - Forest Service Schedule of Proposed...

    Open Energy Info (EERE)

    Actions Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: United States Forest Service - Forest Service Schedule of Proposed Actions Abstract The...

  11. Corrective Action

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

    of Corrective Action Complete is demonstrated by one of the following: Eliminate Exposure (11 SMAs, 16 Sites) SMA SITE Submittal Date Document 2M-SMA-2.2 03-003(k) September...

  12. Unsolicited Proposals

    Broader source: Energy.gov [DOE]

    The Department of Energy's (DOE’s) central point of receipt for all Unsolicited Proposals is the National Energy Technology Laboratory (NETL) which includes all DOE Program Research Areas.   

  13. EA-1595: Mitigation Action Plan | Department of Energy

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

    Mitigation Action Plan EA-1595: Mitigation Action Plan Davis-Mead 230-kV Transmission Line Reconductor Project Western Area Power Administration proposes to reconductor ...

  14. EIS-0389: Mitigation Action Plan | Department of Energy

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

    Action Plan EIS-0389: Mitigation Action Plan Trinity Public Utilities District Direct Interconnection Project Western Area Power Administration (Western) proposes to...

  15. Proposed Rules

    Energy Savers [EERE]

    EIS, Draft Corridors - September 2007. | Department of Energy Proposed Energy Transport Corridors: West-wide energy corridor programmatic EIS, Draft Corridors - September 2007. Proposed Energy Transport Corridors: West-wide energy corridor programmatic EIS, Draft Corridors - September 2007. Map of the area covered by a programmatic environmental impact statement (PEIS), "Designation of Energy Corridors on Federal Land in the 11 Western States" (DOE/EIS-0386) to address the

  16. Proposal Process

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

    Proposal Process Network R&D Software-Defined Networking (SDN) Experimental Network Testbeds 100G SDN Testbed Testbed Description Proposal Process Terms and Conditions Dark Fiber Testbed Test Circuit Service Testbed Results Current Testbed Research Previous Testbed Research Performance (perfSONAR) Software & Tools Development Data for Researchers Partnerships Publications Workshops Contact Us Technical Assistance: 1 800-33-ESnet (Inside US) 1 800-333-7638 (Inside US) 1 510-486-7600

  17. Proposed Rules

    National Nuclear Security Administration (NNSA)

    4414 Federal Register / Vol. 78, No. 209 / Tuesday, October 29, 2013 / Proposed Rules NRC about the availability of information for the proposed Waste Confidence rule and DGEIS. You may access publicly available information related to these documents by any of the following methods: * Federal Rulemaking Web Site: Go to http://www.regulations.gov and search for Docket ID NRC-2012-0246. * NRC's Waste Confidence Web site: Go to http://www.nrc.gov/waste/spent- fuel-storage/wcd.html. * NRC's

  18. Unsolicited Proposals

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

    2002-02-27

    The order sets forth Department of Energy (DOE) requirements and responsibilities for the receipt, processing, and review of unsolicited proposals (USPs). To ensure that those submitting USPs are notified in a timely manner of the status (e.g., pending, accepted for funding, or declined) of their Supersedes DOE O 542.2. Certified 12-28-06.

  19. p-doping-free InGaN/GaN light-emitting diode driven by three-dimensional hole gas

    SciTech Connect (OSTI)

    Zhang, Zi-Hui; Tiam Tan, Swee; Kyaw, Zabu; Liu, Wei; Ji, Yun; Ju, Zhengang; Zhang, Xueliang [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore) [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Wei Sun, Xiao, E-mail: EXWSUN@ntu.edu.sg [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Department of Electronics and Electrical Engineering, South University of Science and Technology of China, Shenzhen, Guangdong 518055 (China); Volkan Demir, Hilmi, E-mail: VOLKAN@stanfordalumni.org [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Department of Electrical and Electronics, UNAM-Institute of Material Science and Nanotechnology, Bilkent University, Ankara TR-06800 (Turkey); Department of Physics, UNAM-Institute of Material Science and Nanotechnology, Bilkent University, Ankara TR-06800 (Turkey)

    2013-12-23

    Here, GaN/Al{sub x}Ga{sub 1-x}N heterostructures with a graded AlN composition, completely lacking external p-doping, are designed and grown using metal-organic-chemical-vapour deposition (MOCVD) system to realize three-dimensional hole gas (3DHG). The existence of the 3DHG is confirmed by capacitance-voltage measurements. Based on this design, a p-doping-free InGaN/GaN light-emitting diode (LED) driven by the 3DHG is proposed and grown using MOCVD. The electroluminescence, which is attributed to the radiative recombination of injected electrons and holes in InGaN/GaN quantum wells, is observed from the fabricated p-doping-free devices. These results suggest that the 3DHG can be an alternative hole source for InGaN/GaN LEDs besides common Mg dopants.

  20. Mitigation Action Plan

    SciTech Connect (OSTI)

    Not Available

    1994-02-01

    This Mitigation Action Plan (MAP) focuses on mitigation commitments stated in the Supplemental Environmental Impact Statement (SEIS) and the Record of Decision (ROD) for the Naval Petroleum Reserve No. 1 (NPR-1). Specific commitments and mitigation implementation actions are listed in Appendix A-Mitigation Actions, and form the central focus of this MAP. They will be updated as needed to allow for organizational, regulatory, or policy changes. It is the intent of DOE to comply with all applicable federal, state, and local environmental, safety, and health laws and regulations. Eighty-six specific commitments were identified in the SEIS and associated ROD which pertain to continued operation of NPR-1 with petroleum production at the Maximum Efficient Rate (MER). The mitigation measures proposed are expected to reduce impacts as much as feasible, however, as experience is gained in actual implementation of these measures, some changes may be warranted.

  1. GaNPAs Solar Cells Lattice-Matched To GaP: Preprint

    SciTech Connect (OSTI)

    Geisz, J. F.; Friedman, D. J.; Kurtz, S.

    2002-05-01

    This conference paper describes the III-V semiconductors grown on silicon substrates are very attractive for lower-cost, high-efficiency multijunction solar cells, but lattice-mismatched alloys that result in high dislocation densities have been unable to achieve satisfactory performance. GaNxP1-x-yAsy is a direct-gap III-V alloy that can be grown lattice-matched to Si when y= 4.7x - 0.1. We propose the use of lattice-matched GaNPAs on silicon for high-efficiency multijunction solar cells. We have grown GaNxP1-x-yAsy on GaP (with a similar lattice constant to silicon) by metal-organic chemical vapor phase epitaxy with direct band-gaps in the range of 1.5 to 2.0 eV. We demonstrate the performance of single-junction GaNxP1-x-yAsy solar cells grown on GaP substrates and discuss the prospects for the development of monolithic high-efficiency multijunction solar cells based on silicon substrates.

  2. General Atomics (GA) | Princeton Plasma Physics Lab

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

    General Atomics (GA) Subscribe to RSS - General Atomics (GA) General Atomics Image: General Atomics (GA) The Scorpion's Strategy: "Catch and Subdue" Read more about The Scorpion's...

  3. Defining the no action alternative for NEPA document of continuing actions

    SciTech Connect (OSTI)

    McCold, L.N.; Saulsbury, J.W.

    1995-12-01

    Environmental professionals today must address many issues that might not have been foreseen by developers of the National Environmental Policy Act of 1969 (NEPA) or the President`s Council on Environmental Quality (CEQ) regulations for implementing NEPA. One issue is the definition of the no action alternative for NEPA documentation of continuing actions. The CEQ regulations do not define the no action alternative, but merely state that NEPA analyses shall {open_quotes}include the alternative of no action{close_quotes}. For NEPA analyses of newly proposed actions, the practical definition of the no action alternative is clear (i.e., the agency will not implement the proposed action or alternative actions). However, the practical definition for NEPA analyses of continuing actions is not so clear. To clarify the definition of the no action alternative for continuing actions, particularly those that involve agency decisions about relicensing existing projects or continuing to operate existing programs or facilities. In trying to clarify the definition of the no action alternative for continuing actions, this paper examines the function of the no action alternative for NEPA analyses in general. Pertinent issues include how the definition of the no action alternative affects the selection of the baseline for environmental analysis and whether inclusion of the no action alternative really forces agencies to consider no action as a realistic alternative. To address these issues, this paper begins with a discussion of relevant legal decisions involving the no action alternative in NEPA analyses. The paper then examines some agency NEPA regulations and recent NEPA documents to provide examples of how some agencies address the no action alternative for continuing actions. Finally, the paper suggests definitions of the no action alternative for continuing actions and methods for addressing no action as a realistic alternative.

  4. Portsmouth Remedial Actions Documents | Department of Energy

    Energy Savers [EERE]

    Remedial Actions Documents Portsmouth Remedial Actions Documents Remedial Action documents for: Portsmouth Site Process Buildings and Complex Facilities D&D Decision Portsmouth Site Site-Wide Waste Disposition Decision Proposed Plan for the Site-wide Waste Disposition Evaluation Project (5.76 MB) Proposed Plan for the Process Buildings and Complex Facilities D&D Evaluation Project (1.66 MB) RI/FS Report for the Site-Wide Waste Disposition Evaluation Project for Portsmouth incl.

  5. EA-1934: Mitigation Action Plan | Department of Energy

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

    Mitigation Action Plan EA-1934: Mitigation Action Plan Expansion of Active Borrow Areas, Hanford Site, Richland, Washington This Mitigation Action Plan is an integral part of the Finding of No Significant Impact for the proposed action within the Expansion of Active Borrow Areas, Hanford Site. The proposed action would expand 11active borrow pits on the Hanford Site that were included in the previous Environmental Assessments (DOE/EA-1403, DOE/EA-1454), and establish 1 new borrow source. This

  6. RCRA corrective action determination of no further action

    SciTech Connect (OSTI)

    1996-06-01

    On July 27, 1990, the U.S. Environmental Protection Agency (EPA) proposed a regulatory framework (55 FR 30798) for responding to releases of hazardous waste and hazardous constituents from solid waste management units (SWMUs) at facilities seeking permits or permitted under the Resource Conservation and Recovery Act (RCRA). The proposed rule, `Corrective Action for Solid Waste Management Units at Hazardous Waste Facilities`, would create a new Subpart S under the 40 CFR 264 regulations, and outlines requirements for conducting RCRA Facility Investigations, evaluating potential remedies, and selecting and implementing remedies (i.e., corrective measures) at RCRA facilities. EPA anticipates instances where releases or suspected releases of hazardous wastes or constituents from SWMUs identified in a RCRA Facility Assessment, and subsequently addressed as part of required RCRA Facility Investigations, will be found to be non-existent or non-threatening to human health or the environment. Such releases may require no further action. For such situations, EPA proposed a mechanism for making a determination that no further corrective action is needed. This mechanism is known as a Determination of No Further Action (DNFA) (55 FR 30875). This information Brief describes what a DNFA is and discusses the mechanism for making a DNFA. This is one of a series of Information Briefs on RCRA corrective action.

  7. 30-Day Federal Register Notice - Proposed

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

    ACTION: Notice and Request for OMB Review and Comment SUMMARY: The Department of Energy (DOE) has submitted to the Office of Management and Budget (OMB) for clearance, a proposal ...

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

    SciTech Connect (OSTI)

    Vladimir Dmitriev

    2007-06-30

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

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

    SciTech Connect (OSTI)

    Mreke, Janina Uren, Michael J.; Kuball, Martin; Novikov, Sergei V.; Foxon, C. Thomas; Hosseini Vajargah, Shahrzad; Wallis, David J.; Humphreys, Colin J.; Haigh, Sarah J.; Al-Khalidi, Abdullah; Wasige, Edward; Thayne, Iain

    2014-07-07

    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.

  10. 30-Day Federal Register Notice - Proposed

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

    Revised 11-2009 30-Day Federal Register Notice - Proposed [6450-01-P] DEPARTMENT OF ENERGY Proposed Agency Information Collection AGENCY: U.S. Department of Energy. ACTION: Notice and Request for OMB Review and Comment SUMMARY: The Department of Energy (DOE) has submitted to the Office of Management and Budget (OMB) for clearance, a proposal for collection of information under the provisions of the Paperwork Reduction Act of 1995. The proposed collection will {enter a brief description of the

  11. 30-Day Federal Register Notice - Proposed

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

    30-Day Federal Register Notice - Proposed [6450-01-P] DEPARTMENT OF ENERGY Proposed Agency Information Collection AGENCY: U.S. Department of Energy. ACTION: Notice and Request for OMB Review and Comment SUMMARY: The Department of Energy (DOE) has submitted to the Office of Management and Budget (OMB) for clearance, a proposal for collection of information under the provisions of the Paperwork Reduction Act of 1995. The proposed collection will {enter a brief description of the collection that

  12. 60-DAY Federal Register Notice - Proposed

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

    Proposed [6450-01-P] DEPARTMENT OF ENERGY Proposed Agency Information Collection AGENCY: U.S. Department of Energy ACTION: Notice and Request for Comments SUMMARY: The Department of Energy (DOE) invites public comment on a proposed collection of information that DOE is developing for submission to the Office of Management and Budget (OMB) pursuant to the Paperwork Reduction Act of 1995. Comments are invited on: (a) whether the proposed collection of information is necessary for the proper

  13. Discovery in Action - Pacific Northwest National Laboratory

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

    Discovery in Action Discovery in Action

  14. GA SNC Solar | Open Energy Information

    Open Energy Info (EERE)

    GA-SNC Solar Place: Nevada Sector: Solar Product: Nevada-based PV project developer and joint venture of GA-Solar North America and Sierra Nevada Corp. References: GA-SNC...

  15. Property:NEPA Proposed Action | Open Energy Information

    Open Energy Info (EERE)

    line (Alternative D) or two parallel lines (Alternative E) running 63 miles from the Red Substation near Killdeer to the new White Substation and on to the Blue Substation and...

  16. EIS-0385: Notice of Proposed Floodplain and Wetland Actions ...

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

    Announcement The Department of Energy (DOE) is preparing an environmental impact statement (EIS) for site selection for expansion of the Strategic Petroleum Reserve, as required by...

  17. Defining the no-action alternative for National Environmental Policy Act analyses of continuing actions

    SciTech Connect (OSTI)

    McCold, L.N.; Saulsbury, J.W.

    1998-01-01

    The Council on Environmental Quality (CEQ) regulations for implementing the National Environmental Policy Act of 1969 (NEPA) do not define the no-action alternative, stating only that EPA analyses shall include the alternative of no action. The definition of the no-action alternative for newly proposed actions seems clear. However, for continuing actions, the meaning of the no-action alternative is ambiguous. This article examines the overall function of the no-action alternative for NEPA analyses of continuing actions. It begins with a discussion of the conflicting definitions of the no-action alternative for continuing activities, including CEQ regulations and guidelines related to the no-action alternative and legal decisions that have helped establish precedence for defining no action. A review of NEPA regulations and guidelines of 10 federal agencies shows how different agencies define no-action for continuing actions. Review of six recent NEPA documents on continuing actions reveals how their definition of the no-action alternative promote or impede informed decision-making.

  18. EA-1993: Proposed High Explosive Science & Engineering Project...

    Office of Environmental Management (EM)

    The proposed action would be to design, construct, and operate a High Explosive Science ... scientific staff and supporting computational and experimental capabilities as well ...

  19. QER- Comment of Berkshire Environmental Action Team

    Broader source: Energy.gov [DOE]

    Dear members of the Quadrennial Energy Review Task Force, Please find attached comments from the Berkshire Environmental Action Team, Inc. (BEAT) regarding the proposed natural gas pipeline expansion. Thank you for considering our comments.

  20. Status of Corrective Actions

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

    WIPP AIB Report Status of Corrective Actions Status of Corrective Actions at LANL Department of Energy Issues Accident Investigation Board (AIB) Report on February 14 Incident ...

  1. Atomic structure of defects in GaN:Mg grown with Ga polarity

    SciTech Connect (OSTI)

    Liliental-Weber, Z.; Tomaszewicz, T.; Zakharov, D.; Jasinski, J.; O'Keefe, M.A.; Hautakangas, S.; Laakso, A.; Saarinen, K.

    2003-11-25

    Electron microscope phase images, produced by direct reconstruction of the scattered electron wave from a focal series of high-resolution images, were used to determine the nature of defects formed in GaN:Mg crystals. We studied bulk crystals grown from dilute solutions of atomic nitrogen in liquid gallium at high pressure and thin films grown by the MOCVD method. All the crystals were grown with Ga-polarity. In both types of samples the majority of defects were three dimensional Mg-rich hexagonal pyramids with bases on the (0001) plane and six walls on {l_brace}11{und 2}3{r_brace} planes seen in cross-section as triangulars. Some other defects appear in cross-section as trapezoidal (rectangular) defects as a result of presence of truncated pyramids. Both type of defects have hollow centers. They are decorated by Mg on all six side walls and a base. The GaN which grows inside on the defect walls shows polarity inversion. It is shown that change of polarity starts from the defect tip and propagates to the base, and that the stacking sequence changes from ab in the matrix to bc inside the defect. Exchange of the Ga sublattice with the N sublattice within the defect leads to 0.6 {+-} 0.2{angstrom} displacement between Ga sublattices outside and inside the defects. It is proposed that lateral overgrowth of the cavities formed within the defect takes place to restore matrix polarity on the defect base.

  2. RCRA corrective action program guide (Interim)

    SciTech Connect (OSTI)

    Not Available

    1993-05-01

    The US Department of Energy (DOE) is responsible for compliance with an increasingly complex spectrum of environmental regulations. One of the most complex programs is the corrective action program proposed by the US Environmental Protection Agency (EPA) under the authority of the Resource Conservation and Recovery Act (RCRA) as amended by the Hazardous and Solid Waste Amendments (HSWA). The proposed regulations were published on July 27, 1990. The proposed Subpart S rule creates a comprehensive program for investigating and remediating releases of hazardous wastes and hazardous waste constituents from solid waste management units (SWMUs) at facilities permitted to treat, store, or dispose of hazardous wastes. This proposed rule directly impacts many DOE facilities which conduct such activities. This guidance document explains the entire RCRA Corrective Action process as outlined by the proposed Subpart S rule, and provides guidance intended to assist those persons responsible for implementing RCRA Corrective Action at DOE facilities.

  3. GaInNAs laser gain

    SciTech Connect (OSTI)

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

    2000-05-23

    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.

  4. Electronic contribution to friction on GaAs

    SciTech Connect (OSTI)

    Applied Science and Technology Graduate Group, UC Berkeley; Dept. of Materials Sciences and Engineering, UC Berkeley; Salmeron, Miquel; Qi, Yabing; Park, J.Y.; Hendriksen, B.L.M.; Ogletree, D.F.; Salmeron, Miquel

    2008-04-15

    The electronic contribution to friction at semiconductor surfaces was investigated by using a Pt-coated tip with 50nm radius in an atomic force microscope sliding against an n-type GaAs(100) substrate. The GaAs surface was covered by an approximately 1 nm thick oxide layer. Charge accumulation or depletion was induced by the application of forward or reverse bias voltages. We observed a substantial increase in friction force in accumulation (forward bias) with respect to depletion (reverse bias). We propose a model based on the force exerted by the trapped charges that quantitatively explains the experimental observations of excess friction.

  5. Mitigation Action Plans (MAP) and Related Documents | Department...

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

    EA-1704: Mitigation Action Plan Construction and Operation of a Proposed Cellulosic Biorefinery, BlueFire Fulton Renewable Energy, LLC, Fulton, Mississippi March 10, 2010...

  6. EIS-0425: Mitigation Action Plan | Department of Energy

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

    Project BPA decided to implement the Proposed Action of the Mid-Columbia Coho Restoration Program as described in the Mid-Columbia Coho Restoration Program Final Environmental...

  7. EIS-0384: Mitigation Action Plan | Department of Energy

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

    project designers and reviewers minimized short-term and long-term environmental and social impacts of the Proposed Action through project design, consultation with regulatory...

  8. Department of Energy Initiates Formal Enforcement Action in Los...

    Office of Environmental Management (EM)

    actions today against the University of California (UC) and the Los Alamos National ... of Violation to the University of California with a 3,000,000 proposed civil ...

  9. Corrective Actions Process

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

    Community, Environment » Environmental Stewardship » Environmental Cleanup » Corrective Actions Corrective Actions Process The general process for evaluating and remediating potential release sites is called the corrective action process. Contact Environmental Communication & Public Involvement P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505) 667-0216 Email Corrective actions The Laboratory's corrective actions process refers to the way in which the Laboratory investigates, stabilizes,

  10. LANSCE | User Resources | Proposals

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

    Proposals LANSCE accepts proposals for the Lujan Neutron Scattering Center, Proton Radiography (pRad) and the Weapons Neutron Research Facility (WNR). Calls for proposals are typically issued twice a year, for each run cycle of the accelerator. Deadlines will be posted. Lujan Center pRad WNR Lujan Center call for proposals is closed. Proposal Submission Read the Lujan Center call for proposals. Deadline: May 21, 2016, 5:00 p.m. (MDT) Unclassified Proposal Submission: Unclassified proposals must

  11. 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; Masson, Denis; Riel, Bruno; Fafard, Simon; Jaouad, Abdelatif; Turala, Artur; Ares, Richard; Aimez, Vincent

    2010-10-14

    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}.

  12. DOE Initiates Enforcement Actions Against 4 Showerhead Manufacturers

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

    (Notice of Proposed Civil Penalty and Requests for Test Data Issued) | Department of Energy Initiates Enforcement Actions Against 4 Showerhead Manufacturers (Notice of Proposed Civil Penalty and Requests for Test Data Issued) DOE Initiates Enforcement Actions Against 4 Showerhead Manufacturers (Notice of Proposed Civil Penalty and Requests for Test Data Issued) March 7, 2010 - 3:41pm Addthis The Office of General Counsel has issued a Notice of Proposed Civil Penalty to Hudson-Reed Limited

  13. 2014 Joint Action Workshop

    Broader source: Energy.gov [DOE]

    The Joint Action Workshop is an annual event for joint action agencies and their members to meet informally and discuss emerging policy, regulatory, and power supply issues, and other topics...

  14. General User Proposals (GUPs)

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

    or until the number of shifts recommended by the Proposal Study Panels (PSP) for the life of the proposal have been used. Users may decide whether to submit a new proposal or...

  15. Mitigation Action Plan

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

    Mitigation Action Plan FutureGen 2.0 Project DOE/EIS-0460 U.S. Department of Energy National Energy Technology Laboratory March 2014 DOE/EIS-0460 FUTUREGEN 2.0 PROJECT MITIGATION ACTION PLAN INTENTIONALLY LEFT BLANK DOE/EIS-0460 FUTUREGEN 2.0 PROJECT MITIGATION ACTION PLAN TABLE OF CONTENTS Introduction ................................................................................................................................................... 1 Purpose

  16. Mitigation Action Plan

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

    Mitigation Action Plan FutureGen 2.0 Project DOE/EIS-0460 U.S. Department of Energy National Energy Technology Laboratory March 2014 DOE/EIS-0460 FUTUREGEN 2.0 PROJECT MITIGATION ACTION PLAN INTENTIONALLY LEFT BLANK DOE/EIS-0460 FUTUREGEN 2.0 PROJECT MITIGATION ACTION PLAN TABLE OF CONTENTS Introduction ................................................................................................................................................... 1 Purpose

  17. Temperature coefficients for GaInP/GaAs/GaInNAsSb solar cells

    SciTech Connect (OSTI)

    Aho, Arto; Isoaho, Riku; Tukiainen, Antti; Polojärvi, Ville; Aho, Timo; Raappana, Marianna; Guina, Mircea

    2015-09-28

    We report the temperature coefficients for MBE-grown GaInP/GaAs/GaInNAsSb multijunction solar cells and the corresponding single junction sub-cells. Temperature-dependent current-voltage measurements were carried out using a solar simulator equipped with a 1000 W Xenon lamp and a three-band AM1.5D simulator. The triple-junction cell exhibited an efficiency of 31% at AM1.5G illumination and an efficiency of 37–39% at 70x real sun concentration. The external quantum efficiency was also measured at different temperatures. The temperature coefficients up to 80°C, for the open circuit voltage, the short circuit current density, and the conversion efficiency were determined to be −7.5 mV/°C, 0.040 mA/cm{sup 2}/°C, and −0.09%/°C, respectively.

  18. Trident Call for Proposals

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

    Trident Call for Proposals Trident Call for Proposals Enabling world-class science in high-energy density physics and fundamental laser-matter interactions Contact Operations Team ...

  19. Intense terahertz emission from molecular beam epitaxy-grown GaAs/GaSb(001)

    SciTech Connect (OSTI)

    Sadia, Cyril P.; Laganapan, Aleena Maria; Agatha Tumanguil, Mae; Estacio, Elmer; Somintac, Armando; Salvador, Arnel; Que, Christopher T.; Yamamoto, Kohji; Tani, Masahiko

    2012-12-15

    Intense terahertz (THz) electromagnetic wave emission was observed in undoped GaAs thin films deposited on (100) n-GaSb substrates via molecular beam epitaxy. GaAs/n-GaSb heterostructures were found to be viable THz sources having signal amplitude 75% that of bulk p-InAs. The GaAs films were grown by interruption method during the growth initiation and using various metamorphic buffer layers. Reciprocal space maps revealed that the GaAs epilayers are tensile relaxed. Defects at the i-GaAs/n-GaSb interface were confirmed by scanning electron microscope images. Band calculations were performed to infer the depletion region and electric field at the i-GaAs/n-GaSb and the air-GaAs interfaces. However, the resulting band calculations were found to be insufficient to explain the THz emission. The enhanced THz emission is currently attributed to a piezoelectric field induced by incoherent strain and defects.

  20. EA-1915: Mitigation Action Plan | Department of Energy

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

    Mitigation Action Plan EA-1915: Mitigation Action Plan Proposed Conveyance of Land at the Hanford Site, Richland, Washington DOE prepared a Mitigation Action Plan (MAP) as an integral part of the Finding of No Significant Impact for DOE's EA. For more information on this project, see the project webpage: http://energy.gov/nepa/ea-1915-proposed-conveyance-land-hanford-site-ric... EA-1915-MAP-2015.pdf (86.09 KB) More Documents & Publications EA-1915: Final Environmental Assessment EA-1915:

  1. ADDENDUM TO ACTION DESCRIPTION MEMORANDUM NIAGARA FALLS STORAGE SITE

    Office of Legacy Management (LM)

    ADDENDUM TO ACTION DESCRIPTION MEMORANDUM NIAGARA FALLS STORAGE SITE PROPOSED INTERIM REMEDIAL ACTIONS FOR FY 1983-85 ACCELERATED PROGRAM (1984 VICINITY PROPERTIES CLEANUP) Prepared by Environmental Research Division Argonne National Laboratory Argonne, Illinois July 1984 Prepared for U.S. Department of Energy Oak Ridge Operations Technical Services Division Oak Ridge, Tennessee CONTENTS Page SUMMARY OF PROPOSED ACTION AND RELATED ACTIVITIES ........... 1 HISTORY AND ENVIRONMENTAL SETTING

  2. NETL: Unsolicited Proposals

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

    Unsolicited Proposals The Department of Energy's (DOE's) central point of receipt for all Unsolicited Proposals is the National Energy Technology Laboratory (NETL) as outlined in the link below which includes all DOE Program Research Areas. The "Guide for the Submission of Unsolicited Proposals" provides more information on the unsolicited proposal process. DOE encourages organizations and individuals to submit self-generated, unsolicited proposals that are relevant to DOE's research

  3. PROPOSAL PREPARATION INSTRUCTIONS

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

    Contract No. DE-AC27-08RV14800 Modification No. A015 PROPOSAL PREPARATION INSTRUCTIONS 1. INTRODUCTION This document contains instructions to the contractor for the preparation of a proposal in response to the modification of the contract which defines work that will be funded by and performed under the provisions of the American Recovery and Reinvestment Act (Recovery Act). The contractor shall provide a written proposal consisting of a Technical Proposal and a Cost and Fee Proposal. The

  4. Trident Call for Proposals

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

    Trident Call for Proposals Trident Call for Proposals Enabling world-class science in high-energy density physics and fundamental laser-matter interactions Contact Operations Team Leader Randy Johnson (505) 665-5089 Email Trident Governing Board Contact Ray Leeper (505) 667-3653 Email Call for Proposals 2015-2016 The Trident Laser Facility is accepting proposals for experiments to be performed at the facility during the period October 2015 through September 2016. All proposals submitted are

  5. LANSCE | User Resources | Proposals

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

    Proposals dotline Lujan Center: Material Science FY17 Call for Proposals Proposal Submission: https://www.lanl.gov/orgs/lansce/ Lujan Center Call for Proposals is Open. Deadline: May 21, 2016 at 5:00 pm (MDT). lansce.lanl.gov lansce.lanl.gov/lujan The Los Alamos Neutron Science Center (LANSCE) invites proposals for material science experiments at the Lujan Center addressing science of NNSA and LANL programmatic interest for the September 2016 - February 2017 run cycle. The Lujan Center utilizes

  6. Action Item Review and Status

    Office of Environmental Management (EM)

    Board Action Items Action Item Resolution Action Item Strategic Planning Initiative Optimization Study Resolution Presentation by S. Schneider (HLW System Integrated Project...

  7. Analysis of the GaInP/GaAs/1-eV/Ge Cell and Related Structures for Terrestrial Concentrator Application: Preprint

    SciTech Connect (OSTI)

    Friedman, D. J.; Kurtz, S. R.; Geisz, J. F.

    2002-05-01

    This conference paper describes the analysis of the potential of GaInP/GaAs/1-eV/Ge four-junction solar cell to improve on the efficiency of the state-of-the-art GaInP/GaAs/Ge benchmark. We emphasize three factors: (1) The newly proposed terrestrial concentrator spectrum has a lower ratio of red to blue light than does the old AM1.5 direct standard spectrum. (2) Standard two-layer antireflection coatings do not provide near-zero reflectance over the full spectral range of interest for these devices. (3) GaInNAs junctions used to date for the 1-eV junction have quantum efficiencies less than {approx}75%. These factors all limit the device current, adversely affecting the four-junction efficiency. We discuss strategies for ameliorating this problem, including going to alternate structures such as a GaInP/GaAs/0.9-eV three-junction device.

  8. LANSCE | User Resources | Proposals

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

    Proposals | FY2017 pRad: Call for Proposals Proposal Submission Deadline: 5:00 pm (MST) Wednesday, March 16, 2016. PAC Review: April 6th and 7th, 2016. Call for Proposals: Proton Radiography FY17 The Los Alamos Neutron Science Center (LANSCE) is issuing a Call for Proposals for experiments for the Proton Radiography Facility (pRad) during Fiscal Year 2017. Proposals for FY18 experiments that will not be ready to be performed FY17 will be considered. The proton radiography facility uses 800 MeV

  9. Call for Proposals

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

    Proposals | FY2016 pRad: Call for Proposals Proposal Submission Deadline: 5:00 pm (MST) Wednesday, March 16, 2016. PAC Review: April 6th and 7th, 2016. Call for Proposals: Proton Radiography FY17 The Los Alamos Neutron Science Center (LANSCE) is issuing a Call for Proposals for experiments for the Proton Radiography Facility (pRad) during Fiscal Year 2017. Proposals for FY18 experiments that will not be ready to be performed FY17 will be considered. The proton radiography facility uses 800 MeV

  10. 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.

    2005-11-01

    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.

  11. Action Plan - Hanford Site

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

    Agreement Action Plan Tri-Party Agreement The Agreement Action Plan Announcements List of Approved Changes TPA Project Manager's Lists Modifications for Public Comment Data Management MP-14 WIDS Information Hanford Site Waste Management Units Report Hanford Public Involvement Plan Administrative Record (AR) Related Links Action Plan Email Email Page | Print Print Page | Text Increase Font Size Decrease Font Size Executive Summary 1.0 Introduction 1.1 Purpose 1.2 Regulatory Authorities 1.3

  12. Protective Actions and Reentry

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

    1997-08-21

    This volume defines appropriate protective actions and reentry of a site following an emergency. Canceled by DOE G 151.1-4.

  13. General User Proposals (GUPs)

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

    General User Proposals (GUPs) General User Proposals (GUPs) Print Tuesday, 01 June 2010 09:36 General Users are granted beam time through a peer review proposal process. They may use beamlines and endstations provided by the ALS or the Participating Research Team (PRT) that operates the beamline. Before Submitting a Proposal Review the ALS Beamlines Directory to learn about the research capabilities of individual beamlines at the ALS. Contact the beamline scientist or the local contact listed in

  14. Call for Proposal Submissions

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

    call for proposal submissions Call for Proposal Submissions The Jupiter Laser Facility (JLF) announces that the Request for Proposals for the JLF User Program for experiments in Calendar Year 2017, January through December, is open. Jupiter is a multi-platform, intermediate-scale laser user facility located at Lawrence Livermore National Laboratory. Proposals will be accepted for the laser platforms Titan, Janus, and COMET. Information and submission instructions are available at

  15. Submit CSES Proposals

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

    Submit Proposals Submit CSES Proposals High quality, cutting-edge science in the areas of astrophysics, space physics, solid planetary geoscience, and climate science. Contact Director Reiner Friedel (505) 665-1936 Email Professional Staff Assistant Georgia D. Sanchez (505) 665-0855 Email FY16 Call for Proposals period is now closed. The Center for Space and Earth Science (CSES) at Los Alamos National Laboratory (LANL) annually solicits proposals in the disciplines of geoscience, climate,

  16. Development of 1.25 eV InGaAsN for triple junction solar cells

    SciTech Connect (OSTI)

    LI,N.Y.; SHARPS,P.R.; HILLS,J.S.; HOU,H.; CHANG,PING-CHIH; BACA,ALBERT G.

    2000-05-16

    Development of next generation high efficiency space monolithic multifunction solar cells will involve the development of new materials lattice matched to GaAs. One promising material is 1.05 eV InGaAsN, to be used in a four junction GaInP{sub 2}/GaAs/InGaAsN/Ge device. The AMO theoretical efficiency of such a device is 38--42%. Development of the 1.05 eV InGaAsN material for photovoltaic applications, however, has been difficult. Low electron mobilities and short minority carrier lifetimes have resulted in short minority carrier diffusion lengths. Increasing the nitrogen incorporation decreases the minority carrier lifetime. The authors are looking at a more modest proposal, developing 1.25 eV InGaAsN for a triple junction GaInP{sub 2}/InGaAsN/Ge device. The AMO theoretical efficiency of this device is 30--34%. Less nitrogen and indium are required to lower the bandgap to 1.25 eV and maintain the lattice matching to GaAs. Hence, development and optimization of the 1.25 eV material for photovoltaic devices should be easier than that for the 1.05 eV material.

  17. On the redox origin of surface trapping in AlGaN/GaN high electron mobility transistors

    SciTech Connect (OSTI)

    Gao, Feng; Chen, Di; Tuller, Harry L.; Thompson, Carl V.; Palacios, Toms

    2014-03-28

    Water-related redox couples in ambient air are identified as an important source of the surface trapping states, dynamic on-resistance, and drain current collapse in AlGaN/GaN high electron mobility transistors (HEMTs). Through in-situ X-ray photoelectron spectroscopy (XPS), direct signature of the water-related specieshydroxyl groups (OH) was found at the AlGaN surface at room temperature. It was also found that these species, as well as the current collapse, can be thermally removed above 200?C in vacuum conditions. An electron trapping mechanism based on the H{sub 2}O/H{sub 2} and H{sub 2}O/O{sub 2} redox couples is proposed to explain the 0.5?eV energy level commonly attributed to the surface trapping states. Finally, the role of silicon nitride passivation in successfully removing current collapse in these devices is explained by blocking the water molecules away from the AlGaN surface.

  18. WREP Mitigation Action Plan

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

    Electrical Interconnection of the Whistling Ridge Energy Project 1 Mitigation Action Plan June 2015 Mitigation Action Plan for the Whistling Ridge Energy Project Measure Implementation Timeline Implementation Responsibility Earth (geology, soils, topography, and geologic hazards) Prior to Project construction, confirm subsurface soil and rock types and strength properties through a detailed geotechnical investigation of the specific locations of all wind Project elements, including wind

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

    DOE Patents [OSTI]

    Kurtz, Steven R.; Allerman, Andrew A.; Klem, John F.; Jones, Eric D.

    2001-01-01

    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%.

  20. Magnetism and transport properties of epitaxial Fe-Ga thin films on GaAs(001)

    SciTech Connect (OSTI)

    Duong Anh Tuan; Shin, Yooleemi; Cho, Sunglae; Dang Duc Dung; Vo Thanh Son

    2012-04-01

    Epitaxial Fe-Ga thin films in disordered bcc {alpha}-Fe crystal structure (A2) have been grown on GaAs(001) by molecular beam epitaxy. The saturated magnetization (M{sub S}) decreased from 1371 to 1105 kA/m with increasing Ga concentration from 10.5 to 24.3 % at room temperature. The lattice parameter increased with the increase in Ga content because of the larger atomic radius of Ga atom than that of Fe. The increase in carrier density with Ga content caused in lower resistivity.

  1. 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

    2014-10-20

    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.

  2. Band Structure of Strain-Balanced GaAsBi/GaAsN Super-lattices on GaAs

    SciTech Connect (OSTI)

    Hwang, J.; Phillips, J. D.

    2011-05-31

    GaAs alloys with dilute content of Bi and N provide a large reduction in band-gap energy with increasing alloy composition. GaAsBi/GaAsN heterojunctions have a type-II band alignment, where superlattices based on these materials offer a wide range for designing effective band-gap energy by varying superlattice period and alloy composition. The miniband structure and effective band gap for strain-balanced GaAsBi/GaAsN superlattices with effective lattice match to GaAs are calculated for alloy compositions up to 5% Bi and N using the kp method. The effective band gap for these superlattices is found to vary between 0.89 and 1.32 eV for period thickness ranging from 10 to 100 . The joint density of states and optical absorption of a 40/40 GaAs0.96Bi0.04/GaAs0.98N0.02 superlattice are reported demonstrating a ground-state transition at 1.005 eV and first excited transition at 1.074 eV. The joint density of states is similar in magnitude to GaAs, while the optical absorption is approximately one order of magnitude lower due to the spatially indirect optical transition in the type-II structure. The GaAsBi/GaAsN system may provide a new material system with lattice match to GaAs in a spectral range of high importance for optoelectronic devices including solar cells, photodetectors, and light emitters.

  3. Optical and magnetotransport properties of InGaAs/GaAsSb/GaAs structures doped with a magnetic impurity

    SciTech Connect (OSTI)

    Kalentyeva, I. L. Zvonkov, B. N.; Vikhrova, O. V.; Danilov, Yu. A.; Demina, P. B.; Dorokhin, M. V.; Zdoroveyshchev, A. V.

    2015-11-15

    InGaAs/GaAsSb/GaAs bilayer quantum-well structures containing a magnetic-impurity δ-layer (Mn) at the GaAs/InGaAs interface are experimentally studied for the first time. The structures are fabricated by metal organic chemical-vapor deposition (MOCVD) and laser deposition on substrates of conducting (n{sup +}) and semi-insulating GaAs in a single growth cycle. The InGaAs-layer thickness is varied from 1.5 to 5 nm. The significant effect of a decrease in the InGaAs quantum-well thickness on the optical and magnetotransport properties of the structures under study is detected. Nonlinear magnetic-field dependence of the Hall resistance and negative magnetoresistance at temperatures of ≤30–40 K, circular polarization of the electroluminescence in a magnetic field, opposite behaviors of the photoluminescence and electroluminescence emission intensities in the structures, and an increase in the contribution of indirect transitions with decreasing InGaAs thickness are observed. Simulation shows that these effects can be caused by the influence of the δ-layer of acceptor impurity (Mn) on the band structure and the hole concentration distribution in the bilayer quantum well.

  4. General User Proposals (GUPs)

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

    General User Proposals (GUPs) Print General Users are granted beam time through a peer review proposal process. They may use beamlines and endstations provided by the ALS or the Participating Research Team (PRT) that operates the beamline. Before Submitting a Proposal Review the ALS Beamlines Directory to learn about the research capabilities of individual beamlines at the ALS. Contact the beamline scientist or the local contact listed in the tables, for additional information about the

  5. Requests for Proposals

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

    Requests for Proposals Requests for Proposals World-class experts and capabilities countering all aspects of explosive threats, and aiming predominantly at enhanced detection capabilities. What LACED cannot do LACED is prohibited by US Federal Law from responding to RFPs on its own or as a co-respondent. Organizations responding to a RFP can reference a "unique" capability or service available at LACED in an RFP proposal response. Such a reference should specify that LACED

  6. LANSCE | User Resources | Proposals

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

    2016 Neutron and Nuclear Science Facility Call for Proposals Proposal Submission Neutron and Nuclear Science Facility (WNR and Lujan Center) Deadline: Friday, April 29, 2016, 5:00 pm (MDT). lansce.lanl.gov wnr.lanl.gov The Los Alamos Neutron Science Center (LANSCE) is issuing a Call for Proposals for Nuclear Science at the Lujan Center and WNR Facility for the upcoming run cycle - September 2016 - February 2017. The Neutron and Nuclear Science Research Facility (WNR) and Lujan Center provide

  7. General User Proposal Scores

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

    Proposal Scores Print Scoring Proposals are scored on a scale of 1 to 5, with 1 being the best score and 5 the worst. Reviewers are requested to use the following ranking schema: Must do High Priority Medium Priority Low priority Don't do Beam time is assigned based on each proposal's score in relation to all other proposals for a given beamline. For beamlines where beam time requests exceed available beam time, a cutoff score is assigned after which no beam time is allocated. Individual Beam

  8. Categories for IGPPS Proposals

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

    on an independent, revolutionary scientific idea that has Los Alamos National Laboratory mission relevance. The proposed work must not be related to the programmatic research...

  9. 2015 Electricity Form Proposals

    Gasoline and Diesel Fuel Update (EIA)

    Quarterly Electricity Imports and Exports Report (EIA-111) OMB Clearance Renewal in 2015 ... Report (EIA-111) survey on August 26, 2015. The initial proposals were announced to ...

  10. Proposals and Design Reports

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

    Proposals and Design Reports Proposals and Design Reports Proposal (1/2/04) Proposal Addendum (29/3/04) Physics Case and Detector Technology Report (12/04) Technical Design Report (7/06) Reviews DOE CD-4 DOE 2008 DOE CD-3b CD-3b Readiness DOE CD-1/2/3a CD-2/3a Readiness CD-1 Readiness PAC Report (4/05) Approvals FNAL PAC Approval: April 15, 2004 DOE Critical Decision 1,2,3a (Performance Baseline, Construction Start) Approval: March 30, 2007 DOE Critical Decision 4 (Project Completion) Approval:

  11. General User Proposals (GUPs)

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

    operates the beamline. Before Submitting a Proposal Review the ALS Beamlines Directory to learn about the research capabilities of individual beamlines at the ALS. Contact the...

  12. MITIGATION ACTION PLAN

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

    Georgia MITEC Small Business Boot Camp In Georgia October 4, 2016 9:00AM to 3:00PM EDT Atlanta, GA DOE's Clean Energy Manufacturing Initiative (CEMI) is hosting a MITEC Boot Camp in Atlanta, Georgia coordinated through the Manufacturing Impacts Through Energy and Commerce (MITEC) program. This boot camp is designed to help small- to medium-sized enterprises (SMEs) in advanced energy sectors access DOE national lab capabilities and assets; learn about DOE programs targeting SMEs including the

  13. Determining the band alignment of TbAs:GaAs and TbAs:In0.53Ga0.47As

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

    Bomberger, Cory C.; Vanderhoef, Laura R.; Rahman, Abdur; Shah, Deesha; Chase, D. Bruce; Taylor, Antoinette J.; Azad, Abul K.; Doty, Matthew F.; Zide, Joshua M. O.

    2015-09-10

    Here, we propose and systematically justify a band structure for TbAs nanoparticles in GaAs and In0.53Ga0.47As host matrices. Moreover, fluence-dependent optical-pump terahertz-probe measurements suggest the TbAs nanoparticles have a band gap and provide information on the carrier dynamics, which are determined by the band alignment. Spectrophotometry measurements provide the energy of optical transitions in the nanocomposite systems and reveal a large blue shift in the absorption energy when the host matrix is changed from In0.53Ga0.47As to GaAs. Finally, Hall data provides the approximate Fermi level in each system. From this data, we deduce that the TbAs:GaAs system forms a typemore » I (straddling) heterojunction and the TbAs:In0.53Ga0.47As system forms a type II (staggered) heterojunction.« less

  14. Status of Corrective Actions

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

    Report on February 14 Incident at the Waste Isolation Pilot Project in Carlsbad, New Mexico April 12, 2012 x x Contact Communication Office (505) 667-7000 Corrective Actions...

  15. Notices ACTION: Notice.

    Office of Environmental Management (EM)

    8867 Federal Register Vol. 80, No. 215 Friday, November 6, 2015 Notices ACTION: Notice. SUMMARY: This notice announces EPA's receipt of an application 91163-EUP-R from Texas...

  16. Notices ACTION: Notice.

    Energy Savers [EERE]

    867 Federal Register Vol. 80, No. 215 Friday, November 6, 2015 Notices ACTION: Notice. SUMMARY: This notice announces EPA's receipt of an application 91163-EUP-R from Texas...

  17. Degradation mechanisms of 2 MeV proton irradiated AlGaN/GaN HEMTs...

    Office of Scientific and Technical Information (OSTI)

    irradiated AlGaNGaN HEMTs This content will become publicly available on August 26, 2016 Title: Degradation mechanisms of 2 MeV proton irradiated AlGaNGaN HEMTs Authors: ...

  18. AlGaAsSb/GaSb Distributed Bragg Reflectors Grown by Organometallic Vapor Phase Epitaxy

    SciTech Connect (OSTI)

    C.A. Wang; C.J. Vineis; D.R. Calawa

    2002-02-13

    The first AlGaAsSb/GaSb quarter-wave distributed Bragg reflectors grown by metallic vapor phase epitaxy are reported. The peak reflectance is 96% for a 10-period structure.

  19. Corrective Action Program Guide

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

    2006-03-02

    This Guide was developed to assist the Department of Energy (DOE) organizations and contractors in the development, implementation, and followup of corrective action programs utilizing the feedback and improvement core safety function within DOE's Integrated Safety Management System. This Guide outlines some of the basic principles, concepts, and lessons learned that DOE managers and contractors might consider when implementing corrective action programs based on their specific needs. Canceled by DOE G 414.1-2B. Does not cancel other directives.

  20. Climate Action Champion: Technical

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

    energy.gov/betterbuildings Climate Action Champion: Technical Assistance to the City of Seattle Planning for Seattle's new Building Energy Code Overview The City of Seattle, identified as a Climate Action Champion (CAC) by the Department of Energy (DOE), is revising its 2012 Energy Code, already one of the most progressive in the country. Seattle has made a pledge to be carbon neutral by 2050. Seattle received technical assistance from the Pacific Northwest National Laboratory in order to

  1. (In,Ga)As/GaP electrical injection quantum dot laser

    SciTech Connect (OSTI)

    Heidemann, M. Höfling, S.; Kamp, M.

    2014-01-06

    The paper reports on the realization of multilayer (In,Ga)As/GaP quantum dot (QD) lasers grown by gas source molecular beam epitaxy. The QDs have been embedded in (Al,Ga)P/GaP waveguide structures. Laser operation at 710 nm is obtained for broad area laser devices with a threshold current density of 4.4 kA/cm{sup 2} at a heat-sink temperature of 80 K.

  2. Proposed Rules Federal Register

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

    7963 Vol. 79, No. 128 Thursday, July 3, 2014 DEPARTMENT OF ENERGY 10 CFR Part 429 [Docket No. EERE-2013-BT-NOC-0039] Appliance Standards and Rulemaking Federal Advisory Committee: Cancellation of Open Meetings AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of cancellation of open meetings. SUMMARY: The Department of Energy (DOE) announces the cancellation of open meetings for the Commercial and Industrial Pumps Working Group of the Appliance

  3. Proposed Rules Federal Register

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

    8019 Vol. 80, No. 127 Thursday, July 2, 2015 DEPARTMENT OF ENERGY 5 CFR Chapter XXII 10 CFR Chapters II, III, and X Reducing Regulatory Burden AGENCY: Office of the General Counsel, Department of Energy. ACTION: Request for information (RFI). SUMMARY: As part of its implementation of Executive Order 13563, ''Improving Regulation and Regulatory Review,'' issued by the President on January 18, 2011, the Department of Energy (Department or DOE) is seeking comments and information from interested

  4. Proposed Rules Federal Register

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

    28736 Vol. 81, No. 90 Tuesday, May 10, 2016 DEPARTMENT OF ENERGY 5 CFR Chapter XXIII 10 CFR Chapters II, III, and X Reducing Regulatory Burden AGENCY: Office of the General Counsel, Department of Energy. ACTION: Request for information (RFI). SUMMARY: As part of its implementation of Executive Order 13563, ''Improving Regulation and Regulatory Review,'' issued by the President on January 18, 2011, the Department of Energy (Department or DOE) is seeking comments and information from interested

  5. Proposed Rules Federal Register

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

    75798 Vol. 76, No. 233 Monday, December 5, 2011 DEPARTMENT OF ENERGY 5 CFR Chapter XXIII 10 CFR Chapters II, III, X Reducing Regulatory Burden AGENCY: Office of the General Counsel, Department of Energy. ACTION: Request for information. SUMMARY: As part of its implementation of Executive Order 13563, ''Improving Regulation and Regulatory Review,'' issued by the President on January 18, 2011, the Department of Energy (Department or DOE) is seeking comments and information from interested parties

  6. Proposed Rules Federal Register

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

    28518 Vol. 77, No. 94 Tuesday, May 15, 2012 DEPARTMENT OF ENERGY 5 CFR Chapter XXII 10 CFR Chapters II, III, X Reducing Regulatory Burden AGENCY: Office of the General Counsel, Department of Energy. ACTION: Request for information. SUMMARY: As part of its implementation of Executive Order 13563, ''Improving Regulation and Regulatory Review,'' issued by the President on January 18, 2011, the Department of Energy (Department or DOE) is seeking comments and information from interested parties to

  7. Proposed Rules Federal Register

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

    31548 Vol. 77, No. 103 Tuesday, May 29, 2012 DEPARTMENT OF ENERGY 5 CFR Chapter XXII 10 CFR Chapters II, III, X Reducing Regulatory Burden AGENCY: Office of the General Counsel, Department of Energy. ACTION: Notice of extension of public comment period. SUMMARY: This notice announces that the period for submitting comments on the Department of Energy's (DOE) request for information (RFI) issued as part of its implementation of Executive Order 13563, ''Improving Regulation and Regulatory

  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.

    2005-08-01

    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. Chapter 5 - Publicizing Contract Actions | Department of Energy

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

    5 - Publicizing Contract Actions Chapter 5 - Publicizing Contract Actions Acquisition Guide Chapter 5.1 - Congressional Notifications - (May 2015) (3 MB) 5.2_Synopsizing_Proposed_Non-Competitive_Actions_Citing_the_Authority_of_FAR_6302-1_0.pdf (100.9 KB) More Documents & Publications Policy Flash 2015-20 Policy Flash 2016-29 Update to Congressional Notifications - Acquisition Guide Chapter 5.1 and Guide to Financial Assistance Chapter 2, Section 2.6.1

  10. EA-1704: Mitigation Action Plan | Department of Energy

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

    4: Mitigation Action Plan EA-1704: Mitigation Action Plan Construction and Operation of a Proposed Cellulosic Biorefinery, BlueFire Fulton Renewable Energy, LLC, Fulton, Mississippi This Mitigation Action Plan specifies the methods for implementing mitigation measures that address the potential environmental impacts associated with the construction and operation of a lignocellulosic ethanol refinery, BlueFire Fulton Renewable Energy, LLC in Fulton, Mississippi. EA-1704-MAP-2010.pdf (2.11 MB)

  11. Wong's equations and the small x effective action in QCD (Journal...

    Office of Scientific and Technical Information (OSTI)

    Wong's equations and the small x effective action in QCD Citation Details In-Document Search Title: Wong's equations and the small x effective action in QCD We propose a new form ...

  12. Approved Program Proposals (AP)

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

    Approved Program Proposals (AP) Print An Approved Program (AP) enables an investigator, or a group of investigators, to receive a set percentage of beam time to partner with ALS staff both to carry out an extended research program and to develop new tools and/or new research protocols that will be made available to the general user population. APs are arranged for a period of up to three years. AP Proposal Submission Deadlines January 15 July 15 AP Proposal Submission Guidelines Step 1: Contact

  13. Approved Program Proposals (AP)

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

    Approved Program Proposals (AP) Approved Program Proposals (AP) Print Thursday, 13 May 2010 11:53 An Approved Program (AP) enables an investigator, or a group of investigators, to receive a set percentage of beam time to partner with ALS staff both to carry out an extended research program and to develop new tools and/or new research protocols that will be made available to the general user population. APs are arranged for a period of up to three years. AP Proposal Submission Deadlines January

  14. Approved Program Proposals (AP)

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

    Approved Program Proposals (AP) Print An Approved Program (AP) enables an investigator, or a group of investigators, to receive a set percentage of beam time to partner with ALS staff both to carry out an extended research program and to develop new tools and/or new research protocols that will be made available to the general user population. APs are arranged for a period of up to three years. AP Proposal Submission Deadlines January 15 July 15 AP Proposal Submission Guidelines Step 1: Contact

  15. Approved Program Proposals (AP)

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

    Approved Program Proposals (AP) Print An Approved Program (AP) enables an investigator, or a group of investigators, to receive a set percentage of beam time to partner with ALS staff both to carry out an extended research program and to develop new tools and/or new research protocols that will be made available to the general user population. APs are arranged for a period of up to three years. AP Proposal Submission Deadlines January 15 July 15 AP Proposal Submission Guidelines Step 1: Contact

  16. Approved Program Proposals (AP)

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

    Approved Program Proposals (AP) Print An Approved Program (AP) enables an investigator, or a group of investigators, to receive a set percentage of beam time to partner with ALS staff both to carry out an extended research program and to develop new tools and/or new research protocols that will be made available to the general user population. APs are arranged for a period of up to three years. AP Proposal Submission Deadlines January 15 July 15 AP Proposal Submission Guidelines Step 1: Contact

  17. Approved Program Proposals (AP)

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

    Approved Program Proposals (AP) Print An Approved Program (AP) enables an investigator, or a group of investigators, to receive a set percentage of beam time to partner with ALS staff both to carry out an extended research program and to develop new tools and/or new research protocols that will be made available to the general user population. APs are arranged for a period of up to three years. AP Proposal Submission Deadlines January 15 July 15 AP Proposal Submission Guidelines Step 1: Contact

  18. 2015 Electricity Form Proposals

    Gasoline and Diesel Fuel Update (EIA)

    (Photovoltaic) Survey Forms November 19, 2015 In early 2016 the U.S. Energy Information ... Details will be provided closer to that date. Proposed changes as of December 2015 Forms ...

  19. Approved Program Proposals (AP)

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

    its recommendations to the ALS Division Director. A letter will be sent to the PIs of successful proposals specifying the percentage of beam time and the period of the AP. The...

  20. PROPOSAL PREPARATION INSTRUCTIONS

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

    Contract No. DE-AC27-08RV14800 Modification No. A015 PROPOSAL PREPARATION INSTRUCTIONS 1. ... in response to the modification of the contract which defines work that will be funded ...

  1. Proposal Study Panels

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

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  2. PROPOSED RULEMAKING MEETING

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

    UNITED STATES DEPARTMENT OF ENERGY INTEGRATED INTERAGENCY PRE-APPLICATION (IIP) NOTICE OF PROPOSED RULEMAKING PUBLIC WORKSHOP Washington, D.C. Tuesday, March 22, 2016 PROPOSED RULEMAKING MEETING Page: 2 Anderson Court Reporting -- 703-519-7180 -- www.andersonreporting.net 1 PARTICIPANTS: 2 SARAH BALL Edison Electric Institute 3 CAITLIN CALLAGHAN 4 US DOE/OE 5 LESLIE CARPENTER TEP 6 SUSAN CHILSON 7 American Transmission Company 8 STEPHEN FUSILIER Bureau of Land Management 9 DEVIN GLADDEN 10 US

  3. Proposal Study Panels

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

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  4. Proposal Study Panels

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

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  5. Proposal Study Panels

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

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  6. Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

    SciTech Connect (OSTI)

    Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

    2015-05-04

    We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

  7. ES H action plan

    SciTech Connect (OSTI)

    Not Available

    1991-01-01

    This document contains planned actions to correct the deficiencies identified in the Pre-Tiger Team Self-Assessment (PTTSA), January 1991, of Sandia National Laboratories (SNL -- Albuquerque, New Mexico; Tonopah, Nevada; and Kauai, Hawaii). The Self-Assessment was conducted by a Self-Assessment Working Group consisting of 19 department managers, with support from Environment, Safety, and Health (ES H) professionals, from October through December 1990. Findings from other past audits, dating back to 1985, were reviewed and compared with the PTTSA findings to determine if additional findings, key findings, or root causes were warranted. The resulting ES H Action Plan and individual planned actions were prepared by the ES H Action Plan Project Group with assistance from the Program owners/authors during February and March 1991. The plan was reviewed by SNL Management in April 1991. This document serves as a planning instrument for the Laboratories to aid in the scoping and sizing of activities related to ES H compliance for the coming five years. It will be modified as required to ensure a workload/funding balance and to address the findings resulting from the Tiger Team assessment at SNL, Albuquerque. The process of producing this document has served well to prepare SNL, Albuquerque, for the coming task of producing the required post-Tiger Team action plan document. 8 tabs.

  8. 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.; Fujioka, H.

    2014-05-05

    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.

  9. DOE Withdraws Proposed Rulemaking (Test Procedure) and Proposed...

    Energy Savers [EERE]

    Withdraws Proposed Rulemaking (Test Procedure) and Proposed Coverage Determination (Energy Conservation Standard) for Set-Top Boxes DOE Withdraws Proposed Rulemaking (Test ...

  10. Notes and Action Items

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

    Notes and Action Items Notes and Action Items Report on the NUGEX business meeting of June 6, 2000, in Oak Ridge Minute notes by Bas Braams First of all, many thanks to the organizers of the preceding NUG meeting: Roberta Boucher, David Dean, Brian Hingerty, Bill Kramer, Donald Spong and Malcolm Stocks. Likewise thanks to Brian Hingerty and Mike Minkoff for organizing the Users Helping Users events, and to Tom DeBoni, Osni Marques, Jeffrey Squyres and David Turner for the NERSC training classes.

  11. Appendix VI Corrective Action Strategy

    National Nuclear Security Administration (NNSA)

    ......... 15 3.0 Underground Test Area............ 13 3-1 Underground Test Area Corrective Action ...

  12. EIS-0476: Vogtle Electric Generating Plant in Burke County, GA...

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

    6: Vogtle Electric Generating Plant in Burke County, GA EIS-0476: Vogtle Electric Generating Plant in Burke County, GA EIS-0476: Final Environmental Impact Statement EIS-0476: ...

  13. EA-1628: Construction and Operation of a Proposed Lignocellulosic Biorefinery, Emmetsburg, Iowa

    Broader source: Energy.gov [DOE]

    This EA evaluated the potential environmental impacts of a DOE proposal to provide financial assistance (the Proposed Action) to POET Project LIBERTY, LLC (POET) for the construction and operation...

  14. Unsolicited Proposals | Department of Energy

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

    Unsolicited Proposals Unsolicited Proposals The Department of Energy's (DOE's) central point of receipt for all Unsolicited Proposals is the National Energy Technology Laboratory ...

  15. Proposed Drill Sites

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

    Lane, Michael

    Proposed drill sites for intermediate depth temperature gradient holes and/or deep resource confirmation wells. Temperature gradient contours based on shallow TG program and faults interpreted from seismic reflection survey are shown, as are two faults interpreted by seismic contractor Optim but not by Oski Energy, LLC.

  16. Proposed Drill Sites

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

    Lane, Michael

    2013-06-28

    Proposed drill sites for intermediate depth temperature gradient holes and/or deep resource confirmation wells. Temperature gradient contours based on shallow TG program and faults interpreted from seismic reflection survey are shown, as are two faults interpreted by seismic contractor Optim but not by Oski Energy, LLC.

  17. EIS-0195: Remedial Actions at Operable Unit 4, Fernald Environmental Management Project, Fernald, Ohio

    Broader source: Energy.gov [DOE]

    This EIS evaluates the potential environmental impacts of a proposal to conduct remedial action at Operable Unit 4 at the Fernald Environmental Management Project.

  18. Proposed environmental remediation at Argonne National Laboratory, Argonne, Illinois

    SciTech Connect (OSTI)

    1997-05-01

    The Department of Energy (DOE) has prepared an Environmental Assessment evaluating proposed environmental remediation activity at Argonne National Laboratory-East (ANL-E), Argonne, Illinois. The environmental remediation work would (1) reduce, eliminate, or prevent the release of contaminants from a number of Resource Conservation and Recovery Act (RCRA) Solid Waste Management Units (SWMUs) and two radiologically contaminated sites located in areas contiguous with SWMUs, and (2) decrease the potential for exposure of the public, ANL-E employees, and wildlife to such contaminants. The actions proposed for SWMUs are required to comply with the RCRA corrective action process and corrective action requirements of the Illinois Environmental Protection Agency; the actions proposed are also required to reduce the potential for continued contaminant release. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required.

  19. GaNPAs Solar Cells that Can Be Lattice-Matched to Silicon

    SciTech Connect (OSTI)

    Geisz, J. F.; Friedman, D. J.; McMahon, W. E.; Ptak, A. J.; Kibbler, A. E.; Olson, J. M.; Kurtz, S.; Kramer, C.; Young, M.; Duda, A.; Reedy, R. C.; Keyes, B. M.; Dippo, P.; Metzger, W. K.

    2003-05-01

    III-V semiconductors grown on silicon substrates are very attractive for lower-cost, high-efficiency multijunction solar cells, but lattice-mismatched alloys that result in high dislocation densities have been unable to achieve satisfactory performance. GaNxP1-x-yAsy is a direct-gap III-V alloy that can be grown lattice-matched to Si when y= 4.7x - 0.1. We have proposed the use of lattice-matched GaNPAs on silicon for high-efficiency multijunction solar cells. We have grown GaNxP1-x-yAsy on GaP (with a similar lattice constant to silicon) by metal-organic chemical vapor phase epitaxy with direct bandgaps in the range of 1.5 to 2.0 eV. We have demonstrated the performance of single-junction GaNxP1-x-yAsy solar cells grown on GaP substrates and shown improvements in material quality by reducing carbon and hydrogen impurities through optimization of growth conditions. We have achieved quantum efficiencies (QE) in these cells as high as 60% and PL lifetimes as high as 3.0 ns.

  20. Carrier quenching in InGaP/GaAs double heterostructures

    SciTech Connect (OSTI)

    Wells, Nathan P. Driskell, Travis U.; Hudson, Andrew I.; LaLumondiere, Stephen D.; Lotshaw, William T.; Forbes, David V.; Hubbard, Seth M.

    2015-08-14

    Photoluminescence measurements on a series of GaAs double heterostructures demonstrate a rapid quenching of carriers in the GaAs layer at irradiance levels below 0.1 W/cm{sup 2} in samples with a GaAs-on-InGaP interface. These results indicate the existence of non-radiative defect centers at or near the GaAs-on-InGaP interface, consistent with previous reports showing the intermixing of In and P when free As impinges on the InGaP surface during growth. At low irradiance, these defect centers can lead to sub-ns carrier lifetimes. The defect centers involved in the rapid carrier quenching can be saturated at higher irradiance levels and allow carrier lifetimes to reach hundreds of nanoseconds. To our knowledge, this is the first report of a nearly three orders of magnitude decrease in carrier lifetime at low irradiance in a simple double heterostructure. Carrier quenching occurs at irradiance levels near the integrated Air Mass Zero (AM0) and Air Mass 1.5 (AM1.5) solar irradiance. Additionally, a lower energy photoluminescence band is observed both at room and cryogenic temperatures. The temperature and time dependence of the lower energy luminescence is consistent with the presence of an unintentional InGaAs or InGaAsP quantum well that forms due to compositional mixing at the GaAs-on-InGaP interface. Our results are of general interest to the photovoltaic community as InGaP is commonly used as a window layer in GaAs based solar cells.

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

    SciTech Connect (OSTI)

    Tatebayashi, J. Ota, Y.; Ishida, S.; Nishioka, M.; Iwamoto, S.; Arakawa, Y.

    2014-09-08

    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.

  2. Oxidation of ultrathin GaSe

    SciTech Connect (OSTI)

    Thomas Edwin Beechem; McDonald, Anthony E.; Ohta, Taisuke; Howell, Stephen W.; Kalugin, Nikolai G.; Kowalski, Brian M.; Brumbach, Michael T.; Spataru, Catalin D.; Pask, Jesse A.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga2Se3 and amorphous Se. Furthermore, photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.

  3. Oxidation of ultrathin GaSe

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

    Thomas Edwin Beechem; McDonald, Anthony E.; Ohta, Taisuke; Howell, Stephen W.; Kalugin, Nikolai G.; Kowalski, Brian M.; Brumbach, Michael T.; Spataru, Catalin D.; Pask, Jesse A.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga2Se3 and amorphous Se. Furthermore, photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.

  4. request for proposals

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

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

  5. Proposed Rules IV. Conclusion

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

    686 Federal Register / Vol. 81, No. 44 / Monday, March 7, 2016 / Proposed Rules IV. Conclusion For the reasons cited in this document, the NRC is denying PRM- 50-106. The NRC is denying this petition because the current regulations already address environmental qualification in both mild and design basis event conditions of electrical equipment located both inside and outside of the containment building that is important to safety, and the petitioners did not provide significant new or

  6. Zinc blende GaAs films grown on wurtzite GaN/sapphire templates

    SciTech Connect (OSTI)

    Chaldyshev, V.V.; Nielsen, B.; Mendez, E.E.; Musikhin, Yu.G.; Bert, N.A.; Ma, Zh.; Holden, Todd

    2005-03-28

    1-{mu}m-thick zinc-blende GaAs (111) films were grown by molecular-beam epitaxy on wurtzite GaN/sapphire (0001) templates. In spite of a {approx}20% lattice mismatch, epitaxial growth was realized, so that the GaAs films showed good adhesion and their surface had a larger mirror-like area with an average surface roughness of 10 nm. Transmission electron microscopy revealed a flat and abrupt epitaxial GaAs/GaN interface with some nanocavities and a large number of dislocations. Reasonably good crystalline quality of the GaAs films was confirmed by Raman characterization. Spectroscopic ellipsometry showed sharp interference fringes and characteristic parameters in the range of 0.75-5.3 eV. Photoluminescence study revealed extended band tails and dominance of non-radiative carrier recombination.

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

    SciTech Connect (OSTI)

    Kuppulingam, B. Singh, Shubra Baskar, K.

    2014-04-24

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

  8. Princeton Plasma Physics Lab - General Atomics (GA)

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

    general-atomics-ga General Atomics en The Scorpion's Strategy: "Catch and Subdue" http:www.pppl.govnode1132

  9. SAVEnergy Action Plans

    SciTech Connect (OSTI)

    Mayo, K.; Westby, R.; deMonsabert, S.; Ginsberg, M.

    1994-04-01

    The Department of Energy`s Federal Energy Management Program (FEMP) is charged with carrying out key sections of EPACT and Executive Order 12903, to make the Federal government operate more efficiently. A congressionally mandated energy and water conservation audit program is one component of this growing DOE program. This paper traces the SAVEnergy Action Plan program throughout its development from (1) identifying projects and Agency champions, (2) establishing a protocol and fitting auditors into the program, (3) developing a data base to track the audits and measure their success, and (4) evaluating the process, learning from mistakes, and charting and transferring successes. A major tenet of the SAVEnergy program is to proactively prescreen all audit activities to ensure that -- where audits are done and Action Plans completed -- projects will be done.

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

    SciTech Connect (OSTI)

    Das, Palash Biswas, Dhrubes

    2014-04-24

    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.

  11. Remedial Action Performed

    Office of Legacy Management (LM)

    Aliquippa Forge Site in Aliquippa, Pennsylvania Department of Energy Former Sites Restoration Division Oak Ridge Operations Office November 1996 CERTIFICATION DOCKE.~ FOR THE REMEDIAL ACTION PERFORMED AT THE ALIQUIPPA FORGE SITE IN ALIQUIPPA, PENNSYLVANIA NOVEMBER 1996 Prepared for . UNITED STATES DEPARTMENT OF ENERGY Oak Ridge Operations Office Under Contract No. DE-AC05-9 1 OR2 1949 Bechtel National, Inc. Oak Ridge, Tennessee Bechtel Job No. 14501 CONTENTS Page FIGURES v . . . . . . . . . . .

  12. Remedial Action Performed

    Office of Legacy Management (LM)

    Baker and Williams Warehouses Site in New York, New York, 7997 - 7993 Department of Energy Former Sites Restoration Division Oak Ridge Operations Office November 7 995 CERTIFICATION DOCKET FOR THE REMEDIAL ACTION PERFORMED AT THE BAKER AND WILLIAMS WAREHOUSES SITE IN NEW YORK, NEW YORK, 1991-1993 NOVEMBER 1995 Prepared for United States Department of Energy Oak Ridge Operations Office Under Contract No. DE-AC05-910R21949 BY Bechtel National, Inc. Oak Ridge, Tennessee Bechtel Job No. 14501 __

  13. Remedial Action Performed

    Office of Legacy Management (LM)

    Alba Craft Laboratory and Vicinity Properties Site in Oxford, Ohio C Department of Energy Former Sites Restoration Division Oak Ridge Operations Office January 1997 $$@T Op% 3 @!B . i~d!l Ab Printed on recycled/recyclable paper. CERTIFICATION DOCKET FOR THE REMEDIAL ACTION PERFORMED AT THE FORMER ALBA CRAFT LABORATORY AND VICINITY PROPERTIES SITE IN OXFORD, OHIO JANUARY 1997 Prepared for United States Department of Energy Oak Ridge Operations Office Under Contract No. DE-AC0591 OR2 1949 Bechtel

  14. Interim Action Determination

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

    Interim Action Determination Processing of Plutonium Materials from the DOE Standard 3013 Surveillance Program in H-Canyon at the Savannah River Site The Department of Energy (DOE) is preparing the Surplus Plutonium Disposition Supplemental Environmental Impact Statement (SPD SEIS, DOE/EIS-0283-S2). DOE is evaluating alternatives for disposition of non-pit plutonium that is surplus to the national security needs of the United States. Although the Deputy Secretary of Energy approved Critical

  15. GaTe semiconductor for radiation detection

    DOE Patents [OSTI]

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

    2009-06-23

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

  16. InGaN/GaN multiple-quantum-well light-emitting diodes with a grading InN composition suppressing the Auger recombination

    SciTech Connect (OSTI)

    Zhang, Zi-Hui; Liu, Wei; Ju, Zhengang; Tan, Swee Tiam; Ji, Yun; Kyaw, Zabu; Zhang, Xueliang; Wang, Liancheng; Sun, Xiao Wei E-mail: VOLKAN@stanfordalumni.org; Demir, Hilmi Volkan E-mail: VOLKAN@stanfordalumni.org

    2014-07-21

    In conventional InGaN/GaN light-emitting diodes (LEDs), thin InGaN quantum wells are usually adopted to mitigate the quantum confined Stark effect (QCSE), caused due to strong polarization induced electric field, through spatially confining electrons and holes in small recombination volumes. However, this inevitably increases the carrier density in quantum wells, which in turn aggravates the Auger recombination, since the Auger recombination scales with the third power of the carrier density. As a result, the efficiency droop of the Auger recombination severely limits the LED performance. Here, we proposed and showed wide InGaN quantum wells with the InN composition linearly grading along the growth orientation in LED structures suppressing the Auger recombination and the QCSE simultaneously. Theoretically, the physical mechanisms behind the Auger recombination suppression are also revealed. The proposed LED structure has experimentally demonstrated significant improvement in optical output power and efficiency droop, proving to be an effective solution to this important problem of Auger recombination.

  17. Magnetic coupling in ferromagnetic semiconductor (Ga,Mn)As/(Al,Ga,Mn)As bilayers

    SciTech Connect (OSTI)

    Wang, M.; Wadley, P.; Campion, R. P.; Rushforth, A. W.; Edmonds, K. W.; Gallagher, B. L.; Charlton, T. R.; Kinane, C. J.; Langridge, S.

    2015-08-07

    We report on a study of ferromagnetic semiconductor (Ga,Mn)As/(Al,Ga,Mn)As bilayers using magnetometry and polarized neutron reflectivity (PNR). From depth-resolved characterization of the magnetic structure obtained by PNR, we concluded that the (Ga,Mn)As and (Al,Ga,Mn)As layers have in-plane and perpendicular-to-plane magnetic easy axes, respectively, with weak interlayer coupling. Therefore, the layer magnetizations align perpendicular to each other under low magnetic fields and parallel at high fields.

  18. CONVENTION ON SUPPLEMENTARY COMPENSATION NOTICE OF PROPOSED RULEMAKING |

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

    Department of Energy After a regulatory action has been completed, Executive Order 12866 requires agencies to identify the substantive changes between the draft submitted to Office of Information and Regulatory Affairs (OIRA) for review and the action subsequently announced, and to identify those changes made at the suggestions or recommendation of OIRA. CSC NOPR Compare (3.91 MB) More Documents & Publications CONVENTION ON SUPPLEMENTARY COMPENSATION NOTICE OF PROPOSED RULEMAKING Changes

  19. Accelerated aging of GaAs concentrator solar cells

    SciTech Connect (OSTI)

    Gregory, P.E.

    1982-04-01

    An accelerated aging study of AlGaAs/GaAs solar cells has been completed. The purpose of the study was to identify the possible degradation mechanisms of AlGaAs/GaAs solar cells in terrestrial applications. Thermal storage tests and accelerated AlGaAs corrosion studies were performed to provide an experimental basis for a statistical analysis of the estimated lifetime. Results of this study suggest that a properly designed and fabricated AlGaAs/GaAs solar cell can be mechanically rugged and environmentally stable with projected lifetimes exceeding 100 years.

  20. Corrective Action Plan for Corrective Action Unit 417: Central Nevada Test Area Surface, Nevada

    SciTech Connect (OSTI)

    K. Campbell

    2000-04-01

    This Corrective Action Plan provides methods for implementing the approved corrective action alternative as provided in the Corrective Action Decision Document for the Central Nevada Test Area (CNTA), Corrective Action Unit (CAU) 417 (DOE/NV, 1999). The CNTA is located in the Hot Creek Valley in Nye County, Nevada, approximately 137 kilometers (85 miles) northeast of Tonopah, Nevada. The CNTA consists of three separate land withdrawal areas commonly referred to as UC-1, UC-3, and UC-4, all of which are accessible to the public. CAU 417 consists of 34 Corrective Action Sites (CASs). Results of the investigation activities completed in 1998 are presented in Appendix D of the Corrective Action Decision Document (DOE/NV, 1999). According to the results, the only Constituent of Concern at the CNTA is total petroleum hydrocarbons (TPH). Of the 34 CASs, corrective action was proposed for 16 sites in 13 CASs. In fiscal year 1999, a Phase I Work Plan was prepared for the construction of a cover on the UC-4 Mud Pit C to gather information on cover constructibility and to perform site management activities. With Nevada Division of Environmental Protection concurrence, the Phase I field activities began in August 1999. A multi-layered cover using a Geosynthetic Clay Liner as an infiltration barrier was constructed over the UC-4 Mud Pit. Some TPH impacted material was relocated, concrete monuments were installed at nine sites, signs warning of site conditions were posted at seven sites, and subsidence markers were installed on the UC-4 Mud Pit C cover. Results from the field activities indicated that the UC-4 Mud Pit C cover design was constructable and could be used at the UC-1 Central Mud Pit (CMP). However, because of the size of the UC-1 CMP this design would be extremely costly. An alternative cover design, a vegetated cover, is proposed for the UC-1 CMP.

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

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram E-mail: rajan@ece.osu.edu; Akyol, Fatih; Rajan, Siddharth E-mail: rajan@ece.osu.edu

    2014-10-06

    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. October is Energy Action Month

    Broader source: Energy.gov [DOE]

    President Obama declared October Energy Action Month, and we are sharing tips about how you can save energy.

  3. 3RS action plan

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    The goal of the Solid Waste Interim Steering Committee (SWISC) process is to develop a long-term waste management system for the Greater Toronto Area (GTA), to be in place by 1996, which is environmentally, socially, economically and technically sound. This background report is being released to the public and member Regional Councils to facilitate input to the SWISC planning process. The report documents current reduction, reuse and recycling initiatives in the GTA, identifies opportunities for coordination and collaboration among the GTA communities, and develops an action plan for improving the effectiveness of the reduction, reuse and recycling efforts within the GTA.

  4. VIOLENT FRAMES IN ACTION

    SciTech Connect (OSTI)

    Sanfilippo, Antonio P.; McGrath, Liam R.; Whitney, Paul D.

    2011-11-17

    We present a computational approach to radical rhetoric that leverages the co-expression of rhetoric and action features in discourse to identify violent intent. The approach combines text mining and machine learning techniques with insights from Frame Analysis and theories that explain the emergence of violence in terms of moral disengagement, the violation of sacred values and social isolation in order to build computational models that identify messages from terrorist sources and estimate their proximity to an attack. We discuss a specific application of this approach to a body of documents from and about radical and terrorist groups in the Middle East and present the results achieved.

  5. RCRA corrective action and closure

    SciTech Connect (OSTI)

    Not Available

    1995-02-01

    This information brief explains how RCRA corrective action and closure processes affect one another. It examines the similarities and differences between corrective action and closure, regulators` interests in RCRA facilities undergoing closure, and how the need to perform corrective action affects the closure of DOE`s permitted facilities and interim status facilities.

  6. Proposed solar two project Barstow, California

    SciTech Connect (OSTI)

    Not Available

    1994-01-01

    This Environmental Assessment (EA) evaluates the environmental consequences of the proposed conversion and operation of the existing Solar One Facility in Daggett, Ca, near the city of Barstow, to a nitrate salt based heat transfer system, Solar Two. The EA also addresses the alternatives of different solar conversion technologies and alternative sites and discusses a no action alternative. A primary objective of the Solar Two Project is to demonstrate the technical and economic feasibility of a solar central receiver power plant using molten salt as the thermal storage and transport fluid medium. If successful, the information gathered from the Solar Two Project could be used to design larger commercial solar power plants.

  7. Oklahoma State University proposed Advanced Technology Research Center. Environmental Assessment

    SciTech Connect (OSTI)

    1995-06-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA) evaluating the construction and equipping of the proposed Advanced Technology Research Center (ATRC) at Oklahoma State University (OSU) in Stillwater, Oklahoma. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required.

  8. Semi-automated lab-on-a-chip for dispensing GA-68 radiotracers

    SciTech Connect (OSTI)

    Weinberg, Irving

    2014-03-12

    We solved a technical problem that is hindering American progress in molecular medicine, and restricting US citizens from receiving optimal diagnostic care. Specifically, the project deals with a mother/daughter generator of positron-emitting radiotracers (Ge-68/Ga-68). These generator systems are approved in Europe but cannot be used in the USA, because of safety issues related to possible breakthrough of long-lived Ge-68 (mother) atoms. Europeans have demonstrated abilities of Ga-68-labeled radiotracers to image cancer foci with high sensitivity and specificity, and to use such methods to effectively plan therapy.The USA Food and Drug Administration (FDA) and Nuclear Regulatory Commission (NRC) have taken the position that every patient administration of Ga-68 should be preceded by an assay demonstrated that Ge-68 breakthrough is within acceptable limits. Breakthrough of parent elements is a sensitive subject at the FDA, as evidenced by the recent recall of Rb-82 generators due to inadvertent administrations of Sr-82. Commercially, there is no acceptable rapid method for assaying breakthrough of Ge-68 prior to each human administration. The gamma emissions of daughter Ga-68 have higher energies than the parent Ge-68, so that the shielding assays typically employed for Mo-99/Tc-99m generators cannot be applied to Ga-68 generators. The half-life of Ga-68 is 68 minutes, so that the standard 10-half-life delay (used to assess breakthrough in Sr-82/Rb-82 generators) cannot be applied to Ga-68 generators. As a result of the aforementioned regulatory requirements, Ga-68 generators are sold in the USA for animal use only.The American clinical communitys inability to utilize Ga-68 generators impairs abilities to treat patients domestically, and puts the USA at a disadvantage in developing exportable products. The proposed DOE project aimed to take advantage of recent technological advances developed for lab-on-a-chip (LOC) applications. Based on our experiences

  9. GaP ring-like nanostructures on GaAs (100) with In{sub 0.15}Ga{sub 0.85}As compensation layers

    SciTech Connect (OSTI)

    Prongjit, Patchareewan Pankaow, Naraporn Boonpeng, Poonyasiri Thainoi, Supachok Panyakeow, Somsak Ratanathammaphan, Somchai

    2013-12-04

    We present the fabrication of GaP ring-like nanostructures on GaAs (100) substrates with inserted In{sub 0.15}Ga{sub 0.85}As compensation layers. The samples are grown by droplet epitaxy using solid-source molecular beam epitaxy. The dependency of nanostructural and optical properties of GaP nanostructures on In{sub 0.15}Ga{sub 0.85}As layer thickness is investigated by ex-situ atomic force microscope (AFM) and photoluminescence (PL). It is found that the characteristics of GaP ring-like structures on GaAs strongly depend on the In{sub 0.15}Ga{sub 0.85}As layer thickness.

  10. 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.; Charache, G.W.

    1997-05-01

    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.

  11. 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)

    2013-12-02

    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.

  12. Impact of stress relaxation in GaAsSb cladding layers on quantum dot creation in InAs/GaAsSb structures grown on GaAs (001)

    SciTech Connect (OSTI)

    Bremner, S. P.; Ban, K.-Y.; Faleev, N. N.; Honsberg, C. B.; Smith, D. J.

    2013-09-14

    We describe InAs quantum dot creation in InAs/GaAsSb barrier structures grown on GaAs (001) wafers by molecular beam epitaxy. The structures consist of 20-nm-thick GaAsSb barrier layers with Sb content of 8%, 13%, 15%, 16%, and 37% enclosing 2 monolayers of self-assembled InAs quantum dots. Transmission electron microscopy and X-ray diffraction results indicate the onset of relaxation of the GaAsSb layers at around 15% Sb content with intersected 60° dislocation semi-loops, and edge segments created within the volume of the epitaxial structures. 38% relaxation of initial elastic stress is seen for 37% Sb content, accompanied by the creation of a dense net of dislocations. The degradation of In surface migration by these dislocation trenches is so severe that quantum dot formation is completely suppressed. The results highlight the importance of understanding defect formation during stress relaxation for quantum dot structures particularly those with larger numbers of InAs quantum-dot layers, such as those proposed for realizing an intermediate band material.

  13. Proposal Types | Advanced Photon Source

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

    from anywhere in the world to use the APS through a competitive access process. CAT Member and Staff Proposals Proposals from members and staff of Collaborative Access...

  14. Technical Proposal Disclosure Policy - ITER

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

    Proposal Disclosure Policy - ITER Pursuant to this solicitation, UT-Battelle will treat confidential proposal information as such and will disclose such information on a need to ...

  15. Sodium dichromate expedited response action assessment

    SciTech Connect (OSTI)

    Not Available

    1993-09-01

    The US Environmental Protection Agency (EPA) and Washington Department of Ecology (Ecology) recommended that the US Department of Energy (DOE) perform an expedited response action (ERA) for the Sodium Dichromate Barrel Disposal Landfill. The ERA lead regulatory agency is Ecology and EPA is the support agency. The ERA was categorized as non-time-critical, which required preparation of an engineering evaluation and cost analysis (EE/CA). The EE/CA was included in the ERA proposal. The EE/CA is a rapid, focused evaluation of available technologies using specific screening factors to assess feasibility, appropriateness, and cost. The ERA goal is to reduce the potential for any contaminant migration from the landfill to the soil column, groundwater, and Columbia River. Since the Sodium Dichromate Barrel Disposal Landfill is the only waste site within the operable unit, the removal action may be the final remediation of the 100-IU-4 Operable Unit. This ERA process started in March 1992. The ERA proposal went through a parallel review process with Westinghouse Hanford Company (WHC), DOE Richland Operations (RL), EPA, Ecology, and a 30-day public comment period. Ecology and EPA issued an Action Agreement Memorandum in March 1993 (Appendix A). The memorandum directed excavation of all anomalies and disposal of the collected materials at the Hanford Site Central Landfill. Primary field activities were completed by the end of April 1993. Final waste disposal of a minor quantity of hazardous waste was completed in July 1993.

  16. EA-2006: Finding of No Significant Impact and Mitigation Action Plan |

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

    Department of Energy Finding of No Significant Impact and Mitigation Action Plan EA-2006: Finding of No Significant Impact and Mitigation Action Plan Columbia Estuary Ecosystem Restoration Program Bonneville Power Administration issued a FONSI and a floodplain and wetland statement of findings for a proposed program of actions to help restore ecological structure, function, and biodiversity within the Columbia River estuary. The mitigation measures listed in the Mitigation Action Plan and

  17. Proposed Remedial Action Plan: Proposed Plan for Remedial Action at the Quarry Residuals Operable Unit of the Weldon Spring Site. DOE/OR/21548-724

    Office of Legacy Management (LM)

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

    SciTech Connect (OSTI)

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

    2004-09-24

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

  19. DOE Institutes Enforcement Action against 4 Showerhead Manufacturers for

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

    Failure to Certify 116 Products | Department of Energy Institutes Enforcement Action against 4 Showerhead Manufacturers for Failure to Certify 116 Products DOE Institutes Enforcement Action against 4 Showerhead Manufacturers for Failure to Certify 116 Products January 28, 2010 - 1:49pm Addthis WASHINGTON DC - The Office of General Counsel has issued Notices of Proposed Civil Penalty to Zoe Industries, Altmans Products LLC, EZ-FLO International, and Watermark Designs, Ltd. for failing to

  20. Guam Energy Action Plan

    SciTech Connect (OSTI)

    Conrad, M. D.; Ness, J. E.

    2013-07-01

    Describes the four near-term strategies selected by the Guam Energy Task Force during action planning workshops conducted in March 2013, and outlines the steps being taken to implement those strategies. Each strategy addresses one of the energy sectors identified in the earlier Guam strategic energy plan as being an essential component of diversifying Guam's fuel sources and reducing fossil energy consumption 20% by 2020. The four energy strategies selected are: (1) expanding public outreach on energy efficiency and conservation, (2) establishing a demand-side management revolving loan program, (3) exploring waste-to-energy options, and (4) influencing the transportation sector via anti-idling legislation, vehicle registration fees, and electric vehicles.

  1. Emergencies and Emergency Actions | Department of Energy

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

    and Emergency Actions Emergencies and Emergency Actions Selected documents on the topic of Emergencies and Emergency Actions under NEPA. May 12, 2010 Memorandum for Heads of...

  2. Ecology Action: Small Market Advanced Retrofit Transformation...

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

    Ecology Action: Small Market Advanced Retrofit Transformation Program (SMART) Ecology Action: Small Market Advanced Retrofit Transformation Program (SMART) Ecology Action: Small ...

  3. Climate Action Tracker | Open Energy Information

    Open Energy Info (EERE)

    References: Climate Action Tracker1 "This "Climate Action Tracker" is an independent science-based assessment, which tracks the emission commitments and actions of countries. The...

  4. GaAs photoconductive semiconductor switch

    DOE Patents [OSTI]

    Loubriel, G.M.; Baca, A.G.; Zutavern, F.J.

    1998-09-08

    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.

  5. GaAs photoconductive semiconductor switch

    DOE Patents [OSTI]

    Loubriel, Guillermo M.; Baca, Albert G.; Zutavern, Fred J.

    1998-01-01

    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.

  6. GaN: Defect and Device Issues

    SciTech Connect (OSTI)

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

    1998-11-09

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

  7. On the Modified Palatini Action Coupled to Fermionic Matter

    SciTech Connect (OSTI)

    Lagraa, Meriem Hadjer

    2010-10-31

    From the generalized Palatini's action proposed recently in [1], we show that we can obtain the standard effective action of the theory of Einstein-Cartan coupled to the fermionic matter without the usual current-current interaction. Therefore, an effective action which is free from the Barbero-Immirzi parameter [2] and the non-vanishing torsion resulting from the presence of the minimal coupling of fermionic matter. This establishes the equivalence between the theories of general relativity and Einstein-Cartan minimally coupled to fermions [3].

  8. Corrective Action Investigation Plan for Corrective Action Unit...

    Office of Legacy Management (LM)

    ... Number Title Page 1-1 Process Flow Diagram for Underground Test Area Corrective Action ... NPDES National Pollutant Discharge Elimination System NTS Nevada Test Site pdf Probability ...

  9. Evaluation Criteria for PDIL Proposal

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

    Criteria for PDIL Proposal The selection/decision criteria used by the NCPV Business Development Team are the following: 1. Quality and Relevance of the Proposed Technical Plan (30%) * Technology impact with industry and likelihood of success. Demonstrated benefits of success to both the proposer and NREL to meet the DOE SunShot goals. * Proposed task descriptions and time line. Clear demonstration of entrance and exit strategies in the PDIL. * Extent to which the Proposer and NREL can rapidly

  10. Optical spectroscopy of quantum confined states in GaAs/AlGaAs quantum well tubes

    SciTech Connect (OSTI)

    Shi, Teng; Fickenscher, Melodie; Smith, Leigh; Jackson, Howard; Yarrison-Rice, Jan; Gao, Qiang; Tan, Hoe; Jagadish, Chennupati; Etheridge, Joanne; Wong, Bryan M.

    2013-12-04

    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.

  11. InGaAs/GaAs quantum dot interdiffiusion induced by cap layer overgrowth

    SciTech Connect (OSTI)

    Jasinski, J.; Babinski, A.; Czeczott, M.; Bozek, R.

    2000-06-28

    The effect of thermal treatment during and after growth of InGaAs/GaAs quantum dot (QD) structures was studied. Transmission electron microscopy and atomic force microscopy confirmed the presence of interacting QDs, as was expected from analysis of temperature dependence of QD photoluminescence (PL) peak. The results indicate that the effect of post-growth annealing can be similar to the effect of elevated temperature of capping layer growth. Both, these thermal treatments can lead to a similar In and Ga interdiffiusion resulting in a similar blue-shift of QD PL peak.

  12. 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.; Gotschke, T.; Stoica, T.; Calarco, R.; Sutter, E.; Ciston, J.; Cusco, R.; Artus, L.; Kremling, S.; Hofling, S.; et al

    2011-01-01

    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 GaNmore » 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, μ-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.« less

  13. Structural and optical properties of InGaN--GaN nanowire heterostructures grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Limbach, F.; Gotschke, T.; Stoica, T.; Calarco, R.; Sutter, E.; Ciston, J.; Cusco, R.; Artus, L.; Kremling, S.; Hofling, S.; Worschech, L.; Grutzmacher, D.

    2011-01-01

    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, μ-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.

  14. Structural and optical properties of InGaNGaN nanowire heterostructures grown by molecular beam epitaxy

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

    Limbach, F.; Gotschke, T.; Stoica, T.; Calarco, R.; Sutter, E.; Ciston, J.; Cusco, R.; Artus, L.; Kremling, S.; Ho?fling, S.; et al

    2011-01-01

    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 GaNmoreto 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.less

  15. Investigation of surface-plasmon coupled red light emitting InGaN/GaN multi-quantum well with Ag nanostructures coated on GaN surface

    SciTech Connect (OSTI)

    Li, Yi; Liu, Bin E-mail: rzhang@nju.edu.cn; Zhang, Rong E-mail: rzhang@nju.edu.cn; Xie, Zili; Zhuang, Zhe; Dai, JiangPing; Tao, Tao; Zhi, Ting; Zhang, Guogang; Chen, Peng; Ren, Fangfang; Zhao, Hong; Zheng, Youdou

    2015-04-21

    Surface-plasmon (SP) coupled red light emitting InGaN/GaN multiple quantum well (MQW) structure is fabricated and investigated. The centre wavelength of 5-period InGaN/GaN MQW structure is about 620?nm. The intensity of photoluminescence (PL) for InGaN QW with naked Ag nano-structures (NS) is only slightly increased due to the oxidation of Ag NS as compared to that for the InGaN QW. However, InGaN QW with Ag NS/SiO{sub 2} structure can evidently enhance the emission efficiency due to the elimination of surface oxide layer of Ag NS. With increasing the laser excitation power, the PL intensity is enhanced by 25%53% as compared to that for the SiO{sub 2} coating InGaN QW. The steady-state electric field distribution obtained by the three-dimensional finite-difference time-domain method is different for both structures. The proportion of the field distributed in the Ag NS for the GaN/Ag NS/SiO{sub 2} structure is smaller as compared to that for the GaN/naked Ag NS structure. As a result, the energy loss of localized SP modes for the GaN/naked Ag NS structure will be larger due to the absorption of Ag layer.

  16. Strain-compensated (Ga,In)N/(Al,Ga)N/GaN multiple quantum wells for improved yellow/amber light emission

    SciTech Connect (OSTI)

    Lekhal, K.; Damilano, B. De Mierry, P.; Venngus, P.; Ngo, H. T.; Rosales, D.; Gil, B.; Hussain, S.

    2015-04-06

    Yellow/amber (570600?nm) emitting In{sub x}Ga{sub 1?x}N/Al{sub y}Ga{sub 1?y}N/GaN multiple quantum wells (QWs) have been grown by metal organic chemical vapor deposition on GaN-on- sapphire templates. When the (Al,Ga)N thickness of the barrier increases, the room temperature photoluminescence is red-shifted while its yield increases. This is attributed to an increase of the QW internal electric field and an improvement of the material quality due to the compensation of the compressive strain of the In{sub x}Ga{sub 1?x}N QWs by the Al{sub y}Ga{sub 1?y}N layers, respectively.

  17. Environmental assessment of remedial action at the Maybell uranium mill tailings site near Maybell, Colorado: Revision 2

    SciTech Connect (OSTI)

    Not Available

    1994-11-01

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment and a floodplain/wetlands assessment are included as part of this EA. This report and attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service (FWS).

  18. Environmental assessment of remedial action at the Maybell Uranium Mill Tailings Site near Maybell, Colorado. Revision 1

    SciTech Connect (OSTI)

    Not Available

    1994-04-01

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment (Attachment 1) and a floodplain/wetlands attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service (FWS).

  19. DOE Withdraws Proposed Rulemaking (Test Procedure) and Proposed Coverage

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

    Determination (Energy Conservation Standard) for Set-Top Boxes | Department of Energy Withdraws Proposed Rulemaking (Test Procedure) and Proposed Coverage Determination (Energy Conservation Standard) for Set-Top Boxes DOE Withdraws Proposed Rulemaking (Test Procedure) and Proposed Coverage Determination (Energy Conservation Standard) for Set-Top Boxes December 23, 2013 - 12:00am Addthis The Department of Energy (DOE) has issued pre-publication Federal Register notices withdrawing the notice

  20. Composition profiling of GaAs/AlGaAs quantum dots grown by droplet epitaxy

    SciTech Connect (OSTI)

    Bocquel, J.; Koenraad, P. M.; Giddings, A. D.; Prosa, T. J.; Larson, D. J.; Mano, T.

    2014-10-13

    Droplet epitaxy (DE) is a growth method which can create III-V quantum dots (QDs) whose optoelectronic properties can be accurately controlled through the crystallisation conditions. In this work, GaAs/AlGaAs DE-QDs have been analyzed with the complimentary techniques of cross-sectional scanning tunneling microscopy and atom probe tomography. Structural details and a quantitative chemical analysis of QDs of different sizes are obtained. Most QDs were found to be pure GaAs, while a small proportion exhibited high intermixing caused by a local etching process. Large QDs with a high aspect ratio were observed to have an Al-rich crown above the GaAs QD. This structure is attributed to differences in mobility of the cations during the capping phase of the DE growth.

  1. High-field quasi-ballistic transport in AlGaN/GaN heterostructures

    SciTech Connect (OSTI)

    Danilchenko, B. A.; Tripachko, N. A.; Belyaev, A. E.; Vitusevich, S. A. Hardtdegen, H.; Lth, H.

    2014-02-17

    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.

  2. Environmental Management Headquarters Corrective Action Plan...

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

    II Environmental Management Headquarters Corrective Action Plan - Radiological Release ... actions for addressing Office of Environmental Management (EM) Headquarters (HQ) ...

  3. International Program Action Table - October 2012 | Department...

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

    Communication & Engagement International Programs International Program Action Table - October 2012 International Program Action Table - October 2012 International Program ...

  4. On strongly GA-convex functions and stochastic processes

    SciTech Connect (OSTI)

    Bekar, Nurgl Okur; Akdemir, Hande Gnay; ??can, ?mdat

    2014-08-20

    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.

  5. Sheet resistance under Ohmic contacts to AlGaN/GaN heterostructures

    SciTech Connect (OSTI)

    Hajłasz, M.; Donkers, J. J. T. M.; Sque, S. J.; Heil, S. B. S.; Gravesteijn, D. J.; Rietveld, F. J. R.; Schmitz, J.

    2014-06-16

    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.

  6. On-sun concentrator performance of GaInP/GaAs tandem cells

    SciTech Connect (OSTI)

    Friedman, D.J.; Kurtz, S.R.; Sinha, K.; McMahon, W.E.; Olson, J.M.

    1996-05-01

    The GaInP/GaAs concentrator device has been adapted for and tested in a prototype {open_quotes}real-world{close_quotes} concentrator power system. The device achieved an on-sun efficiency of 28% {+-} 1% in the range of approximately 200-260 suns with device operating temperatures of 38{degrees}C to 42{degrees}C. The authors discuss ways of further improving this performance for future devices.

  7. InGaAs/GaAs (110) quantum dot formation via step meandering

    SciTech Connect (OSTI)

    Diez-Merino, Laura; Tejedor, Paloma

    2011-07-01

    InGaAs (110) semiconductor quantum dots (QDs) offer very promising prospects as a material base for a new generation of high-speed spintronic devices, such as single electron transistors for quantum computing. However, the spontaneous formation of InGaAs QDs is prevented by two-dimensional (2D) layer-by-layer growth on singular GaAs (110) substrates. In this work we have studied, by using atomic force microscopy and photoluminescence spectroscopy (PL), the growth of InGaAs/GaAs QDs on GaAs (110) stepped substrates by molecular beam epitaxy (MBE), and the modification of the adatom incorporation kinetics to surface steps in the presence of chemisorbed atomic hydrogen. The as-grown QDs exhibit lateral dimensions below 100 nm and emission peaks in the 1.35-1.37 eV range. It has been found that a step meandering instability derived from the preferential attachment of In adatoms to [110]-step edges relative to [11n]-type steps plays a key role in the destabilization of 2D growth that leads to 3D mound formation on both conventional and H-terminated vicinal substrates. In the latter case, the driving force for 3D growth via step meandering is enhanced by H-induced upward mass transport in addition to the lower energy cost associated with island formation on H-terminated substrates, which results in a high density array of InGaAs/GaAs dots selectively nucleated on the terrace apices with reduced lateral dimensions and improved PL efficiency relative to those of conventional MBE-grown samples.

  8. 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; Luque, Antonio

    2014-09-26

    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.

  9. Lateral and Vertical Transistors Using the AlGaN/GaN Heterostructure

    SciTech Connect (OSTI)

    Chowdhury, S; Mishra, UK

    2013-10-01

    Power conversion losses are endemic in all areas of electricity consumption, including motion control, lighting, air conditioning, and information technology. Si, the workhorse of the industry, has reached its material limits. Increasingly, the lateral AlGaN/GaN HEMT based on gallium nitride (GaN-on-Si) is becoming the device of choice for medium power electronics as it enables high-power conversion efficiency and reduced form factor at attractive pricing for wide market penetration. The reduced form factor enabled by high-efficiency operation at high frequency further enables significant system price reduction because of savings in bulky extensive passive elements and heat sink costs. The high-power market, however, still remains unaddressed by lateral GaN devices. The current and voltage demand for high power conversion application makes the chip area in a lateral topology so large that it becomes more difficult to manufacture. Vertical GaN devices would play a big role alongside of silicon carbide (SiC) to address the high power conversion needs. In this paper, the development, performance, and status of lateral and vertical GaN devices are discussed.

  10. LAMPF: proposal status and summaries

    SciTech Connect (OSTI)

    Rayburn, L.; Talley, B.

    1982-03-01

    Revisions and additions are given for LAMPF proposal summaries and status reports. These apply to LA-7444-MS. (GHT)

  11. ARM - Propose a Field Campaign

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

    govCampaignsPropose a Campaign Guidelines Overview Annual Facility Call Proposal Deadline Guidance Small Field Campaigns Review Criteria Expectations for Principal Investigators Forms Propose a Campaign Instrument Support Request (ISR) Form (Word, 89KB) Unmanned Aerial System (UAS) Mission Request Form (Word, 72KB) Documentation Submitting Field Campaign Data and Metadata Field Campaign Guidelines (PDF, 574KB) Unmanned Aerial System Operation Safety at ARM Sites (PDF, 639KB) Propose a Campaign :

  12. CY2017 Proposal Submission Instructions

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

    proposal submission instructions CY2017 Proposal Submission Instructions A proposal is necessary for shot-time allocated on the Titan, Janus, and COMET laser platforms at the Jupiter Laser Facility (JLF). The CY2017 period is January through December 2017. JLF will be closed until March 2017 for maintenance and upgrades. Experiment time will be allotted in 4-week Experimental Run Periods, with one-week maintenance breaks between experiments. The schedule will be determined after proposals have

  13. Determining the band alignment of TbAs:GaAs and TbAs:In0.53Ga0.47As

    SciTech Connect (OSTI)

    Bomberger, Cory C.; Vanderhoef, Laura R.; Rahman, Abdur; Shah, Deesha; Chase, D. Bruce; Taylor, Antoinette J.; Azad, Abul K.; Doty, Matthew F.; Zide, Joshua M. O.

    2015-09-10

    Here, we propose and systematically justify a band structure for TbAs nanoparticles in GaAs and In0.53Ga0.47As host matrices. Moreover, fluence-dependent optical-pump terahertz-probe measurements suggest the TbAs nanoparticles have a band gap and provide information on the carrier dynamics, which are determined by the band alignment. Spectrophotometry measurements provide the energy of optical transitions in the nanocomposite systems and reveal a large blue shift in the absorption energy when the host matrix is changed from In0.53Ga0.47As to GaAs. Finally, Hall data provides the approximate Fermi level in each system. From this data, we deduce that the TbAs:GaAs system forms a type I (straddling) heterojunction and the TbAs:In0.53Ga0.47As system forms a type II (staggered) heterojunction.

  14. ESPC ENABLE Final Proposal Requirements

    Broader source: Energy.gov [DOE]

    Document describes the final proposal requirements for consideration by an energy service company (ESCO) for an agency’s Request for Quote/Notice of Opportunity or final proposal. If selected to perform a site investment grade audit, the ESCO will be required to present the findings from the IGA and a project price to the agency in the form of a final proposal.

  15. Mid-infrared pump-related electric-field domains in GaAs/(Al,Ga)As quantum-cascade structures for terahertz lasing without population inversion

    SciTech Connect (OSTI)

    Giehler, M.; Wienold, M.; Schrottke, L.; Hey, R.; Grahn, H. T.; Pavlov, S. G.; Huebers, H.-W.; Winnerl, S.; Schneider, H.

    2011-11-15

    We investigate the effect of mid-infrared (MIR) pumping on the transport properties of GaAs/(Al,Ga)As terahertz (THz) quantum lasers (TQLs), which rely on quantum coherence effects of intersubband transitions. Aiming at THz lasing at elevated temperatures, we extend the concept of THz gain with and without population inversion of a single, MIR-pumped, electrically driven THz stage proposed by Waldmueller et al.[Phys. Rev. Lett. 99, 117401 (2007)] to an entire TQL. However, experiments using a CO{sub 2} as well as a free-electron laser and numerical simulations show that this resonant MIR pumping causes a negative differential conductivity (NDC) in addition to the NDC caused by sequential tunneling. Lasing of these TQLs is prevented by the formation of electric-field domains below the resonance field strength for gain of each single THz stage.

  16. Ohmic contact formation process on low n-type gallium arsenide (GaAs) using indium gallium zinc oxide (IGZO)

    SciTech Connect (OSTI)

    Yang, Seong-Uk; Jung, Woo-Shik; Lee, In-Yeal; Jung, Hyun-Wook; Kim, Gil-Ho; Park, Jin-Hong

    2014-02-01

    Highlights: We propose a method to fabricate non-gold Ohmic contact on low n-type GaAs with IGZO. 0.15 A/cm{sup 2} on-current and 1.5 on/off-current ratio are achieved in the junction. InAs and InGaAs formed by this process decrease an electron barrier height. Traps generated by diffused O atoms also induce a trap-assisted tunneling phenomenon. - Abstract: Here, an excellent non-gold Ohmic contact on low n-type GaAs is demonstrated by using indium gallium zinc oxide and investigating through time of flight-secondary ion mass spectrometry, X-ray photoelectron spectroscopy, transmission electron microscopy, JV measurement, and H [enthalpy], S [entropy], Cp [heat capacity] chemistry simulation. In is diffused through GaAs during annealing and reacts with As, forming InAs and InGaAs phases with lower energy bandgap. As a result, it decreases the electron barrier height, eventually increasing the reverse current. In addition, traps generated by diffused O atoms induce a trap-assisted tunneling phenomenon, increasing generation current and subsequently the reverse current. Therefore, an excellent Ohmic contact with 0.15 A/cm{sup 2} on-current density and 1.5 on/off-current ratio is achieved on n-type GaAs.

  17. Coalescence of GaAs on (001) Si nano-trenches based on three-stage epitaxial lateral overgrowth

    SciTech Connect (OSTI)

    He, Yunrui; Wang, Jun Hu, Haiyang; Wang, Qi; Huang, Yongqing; Ren, Xiaomin

    2015-05-18

    The coalescence of selective area grown GaAs regions has been performed on patterned 1.8 μm GaAs buffer layer on Si via metal-organic chemical vapor deposition. We propose a promising method of three-stage epitaxial lateral overgrowth (ELO) to achieve uniform coalescence and flat surface. Rough surface caused by the coalescence of different growth fronts is smoothened by this method. Low root-mean-square surface roughness of 6.29 nm has been obtained on a 410-nm-thick coalesced ELO GaAs layer. Cross-sectional transmission electron microscope study shows that the coalescence of different growth fronts will induce some new dislocations. However, the coalescence-induced dislocations tend to mutually annihilate and only a small part of them reach the GaAs surface. High optical quality of the ELO GaAs layer has been confirmed by low temperature (77 K) photoluminescence measurements. This research promises a very large scale integration platform for the monolithic integration of GaAs-based device on Si.

  18. 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.

    2006-01-01

    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.

  19. First-principles studies on molecular beam epitaxy growth of GaAs1-xBix

    SciTech Connect (OSTI)

    Luo, Guangfu; Yang, Shujiang; Li, Jincheng; Arjmand, Mehrdad; Szlufarska, Izabela; Brown, April S.; Kuech, Thomas F.; Morgan, Dane

    2015-07-14

    We investigate the molecular beam epitaxy (MBE) growth of GaAs1-xBix film using density functional theory with spin-orbit coupling to understand the growth of this film, especially the mechanisms of Bi incorporation. We study the stable adsorption structures and kinetics of the incident molecules (As? molecule, Ga atom, Bi atom, and Bi? molecule) on the (2 x 1)-Gasub||Bi surface and a proposed q(1 x 1)-Gasub||AsAs surface has a quasi-(1 x 1) As layer above the Ga-terminated GaAs substrate and a randomly oriented As dimer layer on top. We obtain the desorption and diffusion barriers of the adsorbed molecules and also the reaction barriers of three key processes related to Bi evolution, namely, Bi incorporation, As/Bi exchange, and Bi clustering. The results help explain the experimentally observed dependence of Bi incorporation on the As/Ga ratio and growth temperature. Furthermore, we find that As? exchange with Bi of the (2 x 1)-Gasub||Bi surface is a key step controlling the kinetics of the Bi incorporation. Finally, we explore two possible methods to enhance the Bi incorporation, namely, replacing the MBE growth mode from codeposition of all fluxes with a sequential deposition of fluxes and applying asymmetric in-plane strain to the substrate.

  20. Hybrid type-I InAs/GaAs and type-II GaSb/GaAs quantum dot structure with enhanced photoluminescence

    SciTech Connect (OSTI)

    Ji, Hai-Ming; Liang, Baolai Simmonds, Paul J.; Juang, Bor-Chau; Yang, Tao; Young, Robert J.; Huffaker, Diana L.

    2015-03-09

    We investigate the photoluminescence (PL) properties of a hybrid type-I InAs/GaAs and type-II GaSb/GaAs quantum dot (QD) structure grown in a GaAs matrix by molecular beam epitaxy. This hybrid QD structure exhibits more intense PL with a broader spectral range, compared with control samples that contain only InAs or GaSb QDs. This enhanced PL performance is attributed to additional electron and hole injection from the type-I InAs QDs into the adjacent type-II GaSb QDs. We confirm this mechanism using time-resolved and power-dependent PL. These hybrid QD structures show potential for high efficiency QD solar cell applications.

  1. Properties of (Ga,Mn)As codoped with Li

    SciTech Connect (OSTI)

    Miyakozawa, Shohei; Chen, Lin; Matsukura, Fumihiro; Ohno, Hideo

    2014-06-02

    We grow Li codoped (Ga,Mn)As layers with nominal Mn composition up to 0.15 by molecular beam epitaxy. The layers before and after annealing are characterized by x-ray diffraction, transport, magnetization, and ferromagnetic resonance measurements. The codoping with Li reduces the lattice constant and electrical resistivity of (Ga,Mn)As after annealing. We find that (Ga,Mn)As:Li takes similar Curie temperature to that of (Ga,Mn)As, but with pronounced magnetic moments and in-plane magnetic anisotropy, indicating that the Li codoping has nontrivial effects on the magnetic properties of (Ga,Mn)As.

  2. Enforcement actions: Significant actions resolved individual actions. Semiannual progress report, January 1996--June 1996

    SciTech Connect (OSTI)

    1996-08-01

    This document summarizes significant enforcement actions that have been resolved during the period of January-June 1996. The report includes copies of Orders and Notices of Violations sent by the Nuclear Regulatory Commission to individuals with respect to the enforcement actions.

  3. Remedial action plan and site design for stabilization of the inactive uranium mill tailings sites at Slick Rock, Colorado: Remedial Action Selection Report. Preliminary final

    SciTech Connect (OSTI)

    Not Available

    1994-03-01

    This proposed remedial action plan incorporates the results of detailed investigation of geologic, geomorphic, and seismic conditions at the proposed disposal site. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/waterborne materials to a permanent repository at the proposed Burro Canyon disposal cell. The proposed disposal site will be geomorphically stable. Seismic design parameters were developed for the geotechnical analyses of the proposed cell. Cell stability was analyzed to ensure long-term performance of the disposal cell in meeting design standards, including slope stability, settlement, and liquefaction potential. The proposed cell cover and erosion protection features were also analyzed and designed to protect the RRM (residual radioactive materials) against surface water and wind erosion. The location of the proposed cell precludes the need for permanent drainage or interceptor ditches. Rock to be used on the cell top-, side-, and toeslopes was sized to withstand probable maximum precipitation events.

  4. Proposal

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

    More MiniBooNE Antineutrino Data Taking The MiniBooNE Collaboration (Dated: February 4, ... However, the low-energy excess is presently unexplained. Additional antineutrino data and ...

  5. Study of the effects of GaN buffer layer quality on the dc characteristics of AlGaN/GaN high electron mobility transistors

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

    Ahn, Shihyun; Zhu, Weidi; Dong, Chen; Le, Lingcong; Hwang, Ya-Hsi; Kim, Byung-Jae; Ren, Fan; Pearton, Stephen J.; Lind, Aaron G.; Jones, Kevin S.; et al

    2015-04-21

    Here we studied the effect of buffer layer quality on dc characteristics of AlGaN/GaN high electron mobility (HEMTs). AlGaN/GaN HEMT structures with 2 and 5 μm GaN buffer layers on sapphire substrates from two different vendors with the same Al concentration of AlGaN were used. The defect densities of HEMT structures with 2 and 5 μm GaN buffer layer were 7 × 109 and 5 × 108 cm₋2, respectively, as measured by transmission electron microscopy. There was little difference in drain saturation current or in transfer characteristics in HEMTs on these two types of buffer. However, there was no dispersionmore » observed on the nonpassivated HEMTs with 5 μm GaN buffer layer for gate-lag pulsed measurement at 100 kHz, which was in sharp contrast to the 71% drain current reduction for the HEMT with 2 μm GaN buffer layer.« less

  6. Webinar for Tribes, States, Local Governments, and Territories on the Clean Power Plan Supplemental Proposal

    Broader source: Energy.gov [DOE]

    On Tuesday, October 28, 2014, EPA issued an action related to the proposed Clean Power Plan to cut carbon pollution from power plants. EPA is following through on its commitment made in June to...

  7. Reactive codoping of GaAlInP compound semiconductors

    DOE Patents [OSTI]

    Hanna, Mark Cooper; Reedy, Robert

    2008-02-12

    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.

  8. Environmental assessment of remedial action at the Maybell uranium mill tailings site near Maybell, Colorado

    SciTech Connect (OSTI)

    Not Available

    1993-09-01

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment (Attachment 1) and a floodplain/wetlands assessment (Assessment 2) are included as part of this EA. The following sections and attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service.

  9. Three-junction solar cells comprised of a thin-film GaInP/GaAs tandem cell mechanically stacked on a Si cell

    SciTech Connect (OSTI)

    Yazawa, Y.; Tamura, K.; Watahiki, S.; Kitatani, T.; Ohtsuka, H.; Warabisako, T.

    1997-12-31

    Three-junction tandem solar cells were fabricated by mechanical stacking of a thin-film GaInP/GaAs monolithic tandem cell and a Si cell. The epitaxial lift-off (ELO) technique was used for the thinning of GaInP/GaAs tandem cells. Both spectral responses of the GaInP top cell and the GaAs middle cell in the thin-film GaInP/GaAs monolithic tandem cell were conserved. The Si cell performance has been improved by reducing the absorption loss in the GaAs substrate.

  10. American Samoa Energy Action Plan

    SciTech Connect (OSTI)

    Haase, Scott; Esterly, Sean; Herdrich, David; Bodell, Tim; Visser, Charles

    2013-08-01

    Describes the five near-term strategies selected by the American Samoa Renewable Energy Committee (ASREC) during action planning workshops conducted in May 2013, and outlines the actions being taken to implement those strategies. Each option is tied to a priority identified in the earlier draft American Samoa Strategic Energy Plan as being an essential component of reducing American Samoa'spetroleum energy consumption. The actions described for each strategy provide a roadmap to facilitate the implementation of each strategy. This document is intended to evolve along with the advancement of the projects, and will be updated to reflect progress.

  11. RCRA corrective action: Work plans

    SciTech Connect (OSTI)

    Not Available

    1995-02-01

    This Information Brief describes the work plans that owners/operators may have to prepare in conjunction with the performance of corrective action for compliance with RCRA guidelines. In general, the more complicated the performance of corrective action appears from the remedial investigation and other analyses, the more likely it is that the regulator will impose work plan requirements. In any case, most owner/operators will prepare work plans in conjunction with the performance of corrective action processes as a matter of best engineering management practices.

  12. Chemical beam epitaxy growth of AlGaAs/GaAs tunnel junctions using trimethyl aluminium for multijunction solar cells

    SciTech Connect (OSTI)

    Paquette, B.; DeVita, M.; Turala, A.; Kolhatkar, G.; Boucherif, A.; Jaouad, A.; Aimez, V.; Ars, R.; Wilkins, M.; Wheeldon, J. F.; Walker, A. W.; Hinzer, K.; Fafard, S.

    2013-09-27

    AlGaAs/GaAs tunnel junctions for use in high concentration multijunction solar cells were designed and grown by chemical beam epitaxy (CBE) using trimethyl aluminium (TMA) as the p-dopant source for the AlGaAs active layer. Controlled hole concentration up to 4?10{sup 20} cm{sup ?3} was achieved through variation in growth parameters. Fabricated tunnel junctions have a peak tunneling current up to 6140 A/cm{sup 2}. These are suitable for high concentration use and outperform GaAs/GaAs tunnel junctions.

  13. ARM - Submitting Proposals : Guideline Overview

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

    govField CampaignsSubmitting Proposals : Guideline Overview Guidelines Overview Annual Facility Call Proposal Deadline Guidance Small Field Campaigns Review Criteria Expectations for Principal Investigators Forms Propose a Campaign Instrument Support Request (ISR) Form (Word, 89KB) Unmanned Aerial System (UAS) Mission Request Form (Word, 72KB) Documentation Submitting Field Campaign Data and Metadata Field Campaign Guidelines (PDF, 574KB) Unmanned Aerial System Operation Safety at ARM Sites

  14. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1eV)/GaInAs(0.7eV) Four-Junction Solar Cell

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-01-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga{sub 0.5}In{sub 0.5} P/GaAs/Ga{sub 0.75}In{sub 0.25}As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga{sub 0.75}In{sub 0.25}As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap Ga{sub x}In{sub 1-x}As fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the Ga{sub x}In{sub 1-x}As fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  15. Integrating AlGaN/GaN high electron mobility transistor with Si: A comparative study of integration schemes

    SciTech Connect (OSTI)

    Mohan, Nagaboopathy; Raghavan, Srinivasan; Manikant,; Soman, Rohith

    2015-10-07

    AlGaN/GaN high electron mobility transistor stacks deposited on a single growth platform are used to compare the most common transition, AlN to GaN, schemes used for integrating GaN with Si. The efficiency of these transitions based on linearly graded, step graded, interlayer, and superlattice schemes on dislocation density reduction, stress management, surface roughness, and eventually mobility of the 2D-gas are evaluated. In a 500 nm GaN probe layer deposited, all of these transitions result in total transmission electron microscopy measured dislocations densities of 1 to 3 × 10{sup 9}/cm{sup 2} and <1 nm surface roughness. The 2-D electron gas channels formed at an AlGaN-1 nm AlN/GaN interface deposited on this GaN probe layer all have mobilities of 1600–1900 cm{sup 2}/V s at a carrier concentration of 0.7–0.9 × 10{sup 13}/cm{sup 2}. Compressive stress and changes in composition in GaN rich regions of the AlN-GaN transition are the most effective at reducing dislocation density. Amongst all the transitions studied the step graded transition is the one that helps to implement this feature of GaN integration in the simplest and most consistent manner.

  16. Electron tunneling spectroscopy study of electrically active traps in AlGaN/GaN high electron mobility transistors

    SciTech Connect (OSTI)

    Yang, Jie Cui, Sharon; Ma, T. P.; Hung, Ting-Hsiang; Nath, Digbijoy; Krishnamoorthy, Sriram; Rajan, Siddharth

    2013-11-25

    We investigate the energy levels of electron traps in AlGaN/GaN high electron mobility transistors by the use of electron tunneling spectroscopy. Detailed analysis of a typical spectrum, obtained in a wide gate bias range and with both bias polarities, suggests the existence of electron traps both in the bulk of AlGaN and at the AlGaN/GaN interface. The energy levels of the electron traps have been determined to lie within a 0.5?eV band below the conduction band minimum of AlGaN, and there is strong evidence suggesting that these traps contribute to Frenkel-Poole conduction through the AlGaN barrier.

  17. Method for triggering an action

    DOE Patents [OSTI]

    Hall, David R.; Bartholomew, David B.; Johnson, Monte L.; Moon, Justin; Koehler, Roger O.

    2006-10-17

    A method for triggering an action of at least one downhole device on a downhole network integrated into a downhole tool string synchronized to an event comprises determining latency, sending a latency adjusted signal, and performing the action. The latency is determined between a control device and the at least one downhole device. The latency adjusted signal for triggering an action is sent to the downhole device. The action is performed downhole synchronized to the event. A preferred method for determining latency comprises the steps: a control device sends a first signal to the downhole device; after receiving the signal, the downhole device sends a response signal to the control device; and the control device analyzes the time from sending the signal to receiving the response signal.

  18. ICDF Complex Remedial Action Report

    SciTech Connect (OSTI)

    W. M. Heileson

    2007-09-26

    This Idaho CERCLA Disposal Facility (ICDF) Remedial Action Report has been prepared in accordance with the requirements of Section 6.2 of the INEEL CERCLA Disposal Facility Remedial Action Work Plan. The agency prefinal inspection of the ICDF Staging, Storage, Sizing, and Treatment Facility (SSSTF) was completed in June of 2005. Accordingly, this report has been developed to describe the construction activities completed at the ICDF along with a description of any modifications to the design originally approved for the facility. In addition, this report provides a summary of the major documents prepared for the design and construction of the ICDF, a discussion of relevant requirements and remedial action objectives, the total costs associated with the development and operation of the facility to date, and identification of necessary changes to the Agency-approved INEEL CERCLA Disposal Facility Remedial Action Work Plan and the ICDF Complex Operations and Maintenance Plan.

  19. Recapping National Energy Action Month

    Broader source: Energy.gov [DOE]

    Energy Department officials spent National Energy Action Month on the road, meeting and learning from Americans who are advancing our energy security, growing the economy and protecting the environment.

  20. Complexity, action, and black holes

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

    Brown, Adam R.; Roberts, Daniel A.; Susskind, Leonard; Swingle, Brian; Zhao, Ying

    2016-04-18

    In an earlier paper "Complexity Equals Action" we conjectured that the quantum computational complexity of a holographic state is given by the classical action of a region in the bulk (the `Wheeler-DeWitt' patch). We provide calculations for the results quoted in that paper, explain how it fits into a broader (tensor) network of ideas, and elaborate on the hypothesis that black holes are the fastest computers in nature.

  1. Raman spectroscopy of InGaAs/GaAs nanoheterostructures δ-doped with Mn

    SciTech Connect (OSTI)

    Plankina, S. M.; Vikhrova, O. V.; Danilov, Yu. A.; Zvonkov, B. N.; Kalentyeva, I. L.; Nezhdanov, A. V.; Chunin, I. I.; Yunin, P. A.

    2015-01-15

    The results of complex studies of InGaAs/GaAs nanoheterostructures δ-doped with Mn are reported. The structures are grown by metal-organic vapor-phase epitaxy in combination with laser deposition. By confocal Raman spectroscopy, it is shown that the low-temperature δ-doped GaAs cap layers are of higher crystal quality compared to uniformly doped layers. Scattering of light in the coupled phonon-plasmon mode is observed. The appearance of this mode is conditioned by the diffusion of manganese from the δ-layer. The thickness of the cap layer is found to be d{sub c} ≈ 9–20 nm, optimal for attainment of the highest photoluminescence intensity of the quantum well and the highest layer concentration of holes by doping with manganese.

  2. Efficiency enhancement of InGaN/GaN solar cells with nanostructures

    SciTech Connect (OSTI)

    Bai, J.; Yang, C. C.; Athanasiou, M.; Wang, T.

    2014-02-03

    We demonstrate InGaN/GaN multi-quantum-well solar cells with nanostructures operating at a wavelength of 520?nm. Nanostructures with a periodic nanorod or nanohole array are fabricated by means of modified nanosphere lithography. Under 1 sun air-mass 1.5 global spectrum illumination, a fill factor of 50 and an open circuit voltage of 1.9?V are achieved in spite of very high indium content in InGaN alloys usually causing degradation of crystal quality. Both the nanorod array and the nanohole array significantly improve the performance of solar cells, while a larger enhancement is observed for the nanohole array, where the conversion efficiency is enhanced by 51%.

  3. Electrical compensation by Ga vacancies in Ga{sub 2}O{sub 3} thin films

    SciTech Connect (OSTI)

    Korhonen, E.; Tuomisto, F.; Gogova, D.; Wagner, G.; Baldini, M.; Galazka, Z.; Schewski, R.; Albrecht, M.

    2015-06-15

    The authors have applied positron annihilation spectroscopy to study the vacancy defects in undoped and Si-doped Ga{sub 2}O{sub 3} thin films. The results show that Ga vacancies are formed efficiently during metal-organic vapor phase epitaxy growth of Ga{sub 2}O{sub 3} thin films. Their concentrations are high enough to fully account for the electrical compensation of Si doping. This is in clear contrast to another n-type transparent semiconducting oxide In{sub 2}O{sub 3}, where recent results show that n-type conductivity is not limited by cation vacancies but by other intrinsic defects such as O{sub i}.

  4. Graphene in ohmic contact for both n-GaN and p-GaN

    SciTech Connect (OSTI)

    Zhong, Haijian; Liu, Zhenghui; Shi, Lin; Xu, Gengzhao; Fan, Yingmin; Huang, Zengli; Wang, Jianfeng; Ren, Guoqiang; Xu, Ke

    2014-05-26

    The wrinkles of single layer graphene contacted with either n-GaN or p-GaN were found both forming ohmic contacts investigated by conductive atomic force microscopy. The local IV results show that some of the graphene wrinkles act as high-conductive channels and exhibiting ohmic behaviors compared with the flat regions with Schottky characteristics. We have studied the effects of the graphene wrinkles using density-functional-theory calculations. It is found that the standing and folded wrinkles with zigzag or armchair directions have a tendency to decrease or increase the local work function, respectively, pushing the local Fermi level towards n- or p-type GaN and thus improving the transport properties. These results can benefit recent topical researches and applications for graphene as electrode material integrated in various semiconductor devices.

  5. Photocapacitance study of type-II GaSb/GaAs quantum ring solar cells

    SciTech Connect (OSTI)

    Wagener, M. C.; Botha, J. R.; Carrington, P. J.; Krier, A.

    2014-01-07

    In this study, the density of states associated with the localization of holes in GaSb/GaAs quantum rings are determined by the energy selective charging of the quantum ring distribution. The authors show, using conventional photocapacitance measurements, that the excess charge accumulated within the type-II nanostructures increases with increasing excitation energies for photon energies above 0.9?eV. Optical excitation between the localized hole states and the conduction band is therefore not limited to the ?(k?=?0) point, with pseudo-monochromatic light charging all states lying within the photon energy selected. The energy distribution of the quantum ring states could consequently be accurately related from the excitation dependence of the integrated photocapacitance. The resulting band of localized hole states is shown to be well described by a narrow distribution centered 407?meV above the GaAs valence band maximum.

  6. A InGaN/GaN quantum dot green ({lambda}=524 nm) laser

    SciTech Connect (OSTI)

    Zhang Meng; Banerjee, Animesh; Lee, Chi-Sen; Hinckley, John M.; Bhattacharya, Pallab

    2011-05-30

    The characteristics of self-organized InGaN/GaN quantum dot lasers are reported. The laser heterostructures were grown on c-plane GaN substrates by plasma-assisted molecular beam epitaxy and the laser facets were formed by focused ion beam etching with gallium. Emission above threshold is characterized by a peak at 524 nm (green) and linewidth of 0.7 nm. The lowest measured threshold current density is 1.2 kA/cm{sup 2} at 278 K. The slope and wall plug efficiencies are 0.74 W/A and {approx}1.1%, respectively, at 1.3 kA/cm{sup 2}. The value of T{sub 0}=233 K in the temperature range of 260-300 K.

  7. Analysis of defects in GaAsN grown by chemical beam epitaxy on high index GaAs substrates

    SciTech Connect (OSTI)

    Bouzazi, Boussairi; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi

    2013-09-27

    The lattice defects in GaAsN grown by chemical beam epitaxy on GaAs 311B and GaAs 10A toward [110] were characterized and discussed by using deep level transient spectroscopy (DLTS) and on the basis of temperature dependence of the junction capacitances (C{sub J}). In one hand, GaAsN films grown on GaAs 311B and GaAs 10A showed n-type and p-type conductivities, respectively although the similar and simultaneous growth conditions. This result is indeed in contrast to the common known effect of N concentration on the type of conductivity, since the surface 311B showed a significant improvement in the incorporation of N. Furthermore, the temperature dependence of C{sub J} has shown that GaAs 311B limits the formation of N-H defects. In the other hand, the energy states in the forbidden gap of GaAsN were obtained. Six electron traps, E1 to E6, were observed in the DLTS spectrum of GaAsN grown on GaAs 311B, with apparent activation energies of 0.02, 0.14, 0.16, 0.33, 0.48, and 0.74 eV below the bottom edge of the conduction band, respectively. In addition, four hole traps, H1 to H4, were observed in the DLTS spectrum of GaAsN grown on GaAs 10A, with energy depths of 0.13, 0.20, 0.39, and 0.52 eV above the valence band maximum of the alloy, respectively. Hence, the surface morphology of the GaAs substrate was found to play a key factor role in clarifying the electrical properties of GaAsN grown by CBE.

  8. Refractive index of erbium doped GaN thin films

    SciTech Connect (OSTI)

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

    2014-08-25

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

  9. Application of the ASME code in the design of the GA-4 and GA-9 casks

    SciTech Connect (OSTI)

    Mings, W.J. ); Koploy, M.A. )

    1992-01-01

    General Atomics (GA) is developing two spent fuel shipping casks for transport by legal weight truck (LWT). The casks are designed to the loading, environmental conditions and safety requirements defined in Title 10 of the Code of Federal Regulations, Part 71 (10CFR71). To ensure that all components of the cask meet the 10CFR71 rules, GA established structural design criteria for each component based on NRC Regulatory Guides and the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code). This paper discusses the criteria used for different cask components, how they were applied and the conservatism and safety margins built into the criteria and assumption.

  10. Application of the ASME code in the design of the GA-4 and GA-9 casks

    SciTech Connect (OSTI)

    Mings, W.J.; Koploy, M.A.

    1992-08-01

    General Atomics (GA) is developing two spent fuel shipping casks for transport by legal weight truck (LWT). The casks are designed to the loading, environmental conditions and safety requirements defined in Title 10 of the Code of Federal Regulations, Part 71 (10CFR71). To ensure that all components of the cask meet the 10CFR71 rules, GA established structural design criteria for each component based on NRC Regulatory Guides and the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code). This paper discusses the criteria used for different cask components, how they were applied and the conservatism and safety margins built into the criteria and assumption.

  11. Photoluminescence studies of individual and few GaSb/GaAs quantum rings

    SciTech Connect (OSTI)

    Young, M. P.; Woodhead, C. S.; Roberts, J.; Noori, Y. J.; Noble, M. T.; Krier, A.; Hayne, M.; Young, R. J.; Smakman, E. P.; Koenraad, P. M.

    2014-11-15

    We present optical studies of individual and few GaSb quantum rings embedded in a GaAs matrix. Contrary to expectation for type-II confinement, we measure rich spectra containing sharp lines. These lines originate from excitonic recombination and are observed to have resolution-limited full-width at half maximum of 200 ?eV. The detail provided by these measurements allows the characteristic type-II blueshift, observed with increasing excitation power, to be studied at the level of individual nanostructures. These findings are in agreement with hole-charging being the origin of the observed blueshift.

  12. Temperature dependency of the emission properties from positioned In(Ga)As/GaAs quantum dots

    SciTech Connect (OSTI)

    Braun, T.; Schneider, C.; Maier, S.; Forchel, A.; Höfling, S.; Kamp, M.; Igusa, R.; Iwamoto, S.; Arakawa, Y.

    2014-09-15

    In this letter we study the influence of temperature and excitation power on the emission linewidth from site-controlled InGaAs/GaAs quantum dots grown on nanoholes defined by electron beam lithography and wet chemical etching. We identify thermal electron activation as well as direct exciton loss as the dominant intensity quenching channels. Additionally, we carefully analyze the effects of optical and acoustic phonons as well as close-by defects on the emission linewidth by means of temperature and power dependent micro-photoluminescence on single quantum dots with large pitches.

  13. Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces

    SciTech Connect (OSTI)

    Kang, M.; Wu, J. H.; Chen, H. Y.; Thornton, K.; 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); 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); Beskin, I. [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)

    2013-08-12

    We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport.

  14. GaInNAs Structures Grown by MBE for High-Efficiency Solar Cells: Final Report; 25 June 1999--24 August 2002

    SciTech Connect (OSTI)

    Tu, C. W.

    2003-08-01

    The focus of this work is to improve the quality of GaInNAs by advanced thin-film growth techniques, such as digital-alloy growth techniques and migration-enhanced epitaxy (MEE). The other focus is to further investigate the properties of such materials, which are potentially beneficial for high-efficiency, multijunction solar cells. 400-nm-thick strain-compensated Ga0.92In0.08As/GaN0.03As0.97 short-period superlattices (SPSLs) are grown lattice-matched to GaAs substrates. The photoluminescence (PL) intensity of digital alloys is 3 times higher than that of random alloys at room temperature, and the improvement is even greater at low temperature, by a factor of about 12. The room-temperature PL intensity of the GaInNAs quantum well grown by the strained InAs/GaN0.023As SPSL growth mode is higher by a factor 5 as compare to the continuous growth mode. The SPSL growth method allows for independent adjustment of the In-to-Ga ratio without group III competition. MEE reduces the low-energy tail of PL, and PL peaks become more intense and sharper. The twin peaks photoluminescence of GaNAs grown on GaAs was observed at room temperature. The peaks splitting increase with increase in nitrogen alloy content. The strain-induced splitting of light-hole and heavy-hole bands of tensile-strained GaNAs is proposed as an explanation of such behavior.

  15. Enforcement actions: Significant actions resolved individuals actions. Semiannual progress report, July--December 1996

    SciTech Connect (OSTI)

    1997-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July - December 1996) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to-these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

  16. Enforcement actions: Significant actions resolved individual actions. Semiannual progress report, January 1997--June 1997

    SciTech Connect (OSTI)

    1997-09-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (January - June 1997) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

  17. Proposal of Removal Action in the Southeast Drainage. SE-200-201-1.07.

    Office of Legacy Management (LM)

  18. Proposals For Four Interim Response Actions. IR-600-604-1.01.

    Office of Legacy Management (LM)

  19. Proposed Interim Response Action, Construction of Ash Pond Isolation System at the Weldon Spring Site.

    Office of Legacy Management (LM)

  20. Transcript of Proceedings: Quarry Waste Removal Proposed Plan Weldon Spring Site Remedial Action Projec

    Office of Legacy Management (LM)

  1. DOE/EA-1915 MITIGATION ACTION PLAN PROPOSED CONVEYANCE OF LAND...

    Energy Savers [EERE]

    ... including extraction or production of any coal, oil, gas, geothermal steam, associated ... to protect property (e.g., wildlands, buildings, and equipment) by minimizing fire risk. ...

  2. Implementation Proposal for the National Action Plan on Demand Response- July 2011

    Broader source: Energy.gov [DOE]

    Report to Congress prepared by the staff of the Federal Energy Regulatory Commission (FERC) and the Department of Energy.

  3. Baseline requirements of the proposed action for the Transportation Management Division routing models

    SciTech Connect (OSTI)

    Johnson, P.E.; Joy, D.S.

    1995-02-01

    The potential impacts associated with the transportation of hazardous materials are important to shippers, carriers, and the general public. This is particularly true for shipments of radioactive material. The shippers are primarily concerned with safety, security, efficiency, and equipment requirements. The carriers are concerned with the potential impact that radioactive shipments may have on their operations--particularly if such materials are involved in an accident. The general public has also expressed concerns regarding the safety of transporting radioactive and other hazardous materials through their communities. Because transportation routes are a central concern in hazardous material transport, the prediction of likely routes is the first step toward resolution of these issues. In response to these routing needs, several models have been developed over the past fifteen years at Oak Ridge National Laboratory (ORNL). The HIGHWAY routing model is used to predict routes for truck transportation, the INTERLINE routing model is used to predict both rail and barge routes, and the AIRPORT locator model is used to determine airports with specified criteria near a specific location. As part of the ongoing improvement of the US Department of Energy`s (DOE) Environmental Management Transportation Management Division`s (EM-261) computer systems and development efforts, a Baseline Requirements Assessment Session on the HIGHWAY, INTERLINE, and AIRPORT models was held at ORNL on April 27, 1994. The purpose of this meeting was to discuss the existing capabilities of the models and data bases and to review enhancements of the models and data bases to expand their usefulness. The results of the Baseline Requirements Assessment Section will be discussed in this report. The discussions pertaining to the different models are contained in separate sections.

  4. Appliance Standard Program - The FY 2003 Priority -Setting Summary Report and Actions Proposed - Appendix B

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

    APPENDIX B: Data Sheets for Existing Products Table of Contents Product Rulemaking Priority Page Product Rulemaking Priority Page Commercial Air-Cooled Central A/C & Air-Source HP, 65-240 kBtu/h Standards High B-1 High Intensity Discharge Lamps Determination High B-27 Central A/C & HP, 3 phase, < 65 kBtu/h Standards Medium B-2 Test Procedure Low B-28 Clothes Dryers Standards Low B-3 Lamps, Fluorescent Standards Low B-29 Test Procedure Low B-4 Test Procedure Low B-30 Clothes Washers

  5. Appliance Standards Program - The FY 2003 Priority Setting Report and Actions Proposed - Appendix C

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

    APPENDIX C: Data Sheets for New Products Table of Contents Product Page Product Page Commercial Refrigeration Miscellaneous Residential Equipment Standards Consideration C-1 Standards Consideration C-50 Beverage Merchandisers Test Procedure Summary C-3 Ceiling Fans Test Procedure Summary C-52 Standards Consideration C-4 Compact Audio Standards Consideration C-53 Ice Machines Test Procedure Summary C-6 Component Stereo and Rack Audio Standards Consideration C-54 Reach-In Freezers Standards

  6. DOE/EA-1915 MITIGATION ACTION PLAN PROPOSED CONVEYANCE OF LAND...

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

    ... Indian Policy and Order 144.1, Department of Energy Grantor requires Grantee's acoustic and noise signature on the premises will not exceed current Washington State standards and ...

  7. Description of Proposed Interim Remedial Action at the Weldon Spring Site.

    Office of Legacy Management (LM)

  8. Letter: EPA has reviewed the DOE's proposals for the following four interim response actions

    Office of Legacy Management (LM)

  9. GaP/Si heterojunction Solar Cells

    SciTech Connect (OSTI)

    Saive, R.; Chen, C.; Emmer, H.; Atwater, H.

    2015-05-11

    Improving the efficiency of solar cells requires the introduction of novel device concepts. Recent developments have shown that in Si solar cell technology there is still room for tremendous improvement. Using the heterojunction with intrinsic thin layer (HIT) approach 25.6 % power conversion efficiency was achieved. However, a-Si as a window and passivation layer comes with disadvantages as a-Si shows low conductivity and high parasitic absorption. Therefore, it is likely that using a crystalline material as window layer with high band gab and high mobility can further improve efficiency. We have studied GaP grown by MOCVD on Si with (001) and (112) orientation. We obtained crystalline layers with carrier mobility around 100 cm2/Vs and which passivate Si as confirmed by carrier lifetime measurements. We performed band alignment studies by X-ray photoelectron spectroscopy yielding a valence band offset of 0.3 eV. Comparing this value with the Schottky-model leads to an interface dipole of 0.59 eV. The open circuit voltage increases with increasing doping and is consistent with the theoretical open circuit voltage deduced from work function difference and interface dipole. We obtain an open circuit voltage of 0.38 V for n-doped GaP with doping levels in the order of 10^17 1/cm^3. In our next steps we will increase the doping level further in order to gain higher open circuit voltage. We will discuss the implications of these findings for GaP/Si heterojunction solar cells.

  10. Part 3: Removal Action | Department of Energy

    Office of Environmental Management (EM)

    3: Removal Action Part 3: Removal Action Question: When may removal actions be initiated? Answer: Removal actions may be initiated when DOE determines that the action will prevent, minimize, stabilize, or eliminate a risk to health or the environment. The NCP specifies that the determination that a risk to health or the environment is appropriate for removal action should be based on: actual or potential exposure of humans, animals, or the food chain the presence of contained hazardous

  11. Guidance on the Consideration of Past Actions in Cumulative Effects Analysis (CEQ, 2005)

    Broader source: Energy.gov [DOE]

    In this Memorandum, the Council on Environmental Quality provides guidance on the extent to which agencies of the Federal government are required to analyze the environmental effects of past actions when they describe the cumulative environmental effect of a proposed action.

  12. Original Workshop Proposal and Description

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

    Notes for Vis Requirements » Original Workshop Proposal and Description Original Workshop Proposal and Description Visualization Requirements for Computational Science and Engineering Applications Proposal for a DoE Workshop to Be Held 
at the Berkeley Marina Radisson Hotel,
Berkeley, California, June 5, 2002
(date and location are tenative) Workshop Co-organizers: Bernd Hamann 
University of California-Davis Lawrence Berkeley Nat'l Lab. E. Wes Bethel 
Lawrence Berkeley Nat'l Lab.

  13. Modulating emission intensity of GaN-based green light emitting diodes on c-plane sapphire

    SciTech Connect (OSTI)

    Du, Chunhua; Ma, Ziguang; Zhou, Junming; Lu, Taiping; Jiang, Yang; Jia, Haiqiang; Liu, Wuming; Chen, Hong

    2014-04-14

    The asymmetric dual-wavelength (green/blue) coupled InGaN/GaN multiple quantum wells were proposed to modulate the green emission intensity. Electroluminescent measurements demonstrate the conspicuous increment of the green light intensity by decreasing the coupled barrier thickness. This was partly attributed to capture of more carriers when holes tunnel across the thinner barrier from the blue quantum wells, as a hole reservoir, to the green quantum wells. While lower effective barrier height of the blue quantum wells benefits improved hole transportation from p-GaN to the active region. Efficiency droop of the green quantum wells was partially alleviated due to the enhanced injection efficiency of holes.

  14. Distributed bragg reflector using AIGaN/GaN

    DOE Patents [OSTI]

    Waldrip, Karen E.; Lee, Stephen R.; Han, Jung

    2004-08-10

    A supported distributed Bragg reflector or superlattice structure formed from a substrate, a nucleation layer deposited on the substrate, and an interlayer deposited on the nucleation layer, followed by deposition of (Al,Ga,B)N layers or multiple pairs of (Al,Ga,B)N/(Al,Ga,B)N layers, where the interlayer is a material selected from AlN, Al.sub.x Ga.sub.1-x N, and AlBN with a thickness of approximately 20 to 1000 angstroms. The interlayer functions to reduce or eliminate the initial tensile growth stress, thereby reducing cracking in the structure. Multiple interlayers utilized in an AlGaN/GaN DBR structure can eliminate cracking and produce a structure with a reflectivity value greater than 0.99.

  15. Energy Agency Coordinators for Energy Action Month

    Broader source: Energy.gov [DOE]

    Agency coordinators serve as primary Federal agency points of contact for Energy Action Month. Contact them if you have questions about implementing an Energy Action Month campaign.

  16. Inter Action Corp | Open Energy Information

    Open Energy Info (EERE)

    Action Corp Jump to: navigation, search Name: Inter Action Corp Place: Kanagawa, Japan Zip: 236-0004 Product: Semiconductor equipment and testing devices maker building a PV...

  17. Climate Action Plan | OpenEI Community

    Open Energy Info (EERE)

    actions that the administration believes will mitigate the environmental and economic costs of climate change. Obama's six Climate Action Initiatives: 1. Phasing out Fossil Fuels...

  18. California Climate Action Registry | Open Energy Information

    Open Energy Info (EERE)

    Climate Action Registry Jump to: navigation, search Name: California Climate Action Registry Place: Los Angeles, California Zip: 90014 Product: Los Angeles-based NPO which develops...

  19. Renewable Energy Action Project | Open Energy Information

    Open Energy Info (EERE)

    Action Project Jump to: navigation, search Name: Renewable Energy Action Project Place: San Francisco, California Zip: 94107 Product: REAP is a San Francisco-based non-profit...

  20. Energy Action Month October 2013 Poster

    Broader source: Energy.gov [DOE]

    Poster for Federal Energy Management Program (FEMP) features slogan "Take Action Now: Empower a Secure Energy Future" for October 2013 Energy Action Month.

  1. Presidential Climate Action Project | Open Energy Information

    Open Energy Info (EERE)

    Page Edit with form History Presidential Climate Action Project Jump to: navigation, search Name: Presidential Climate Action Project Place: Denver, Colorado Zip: 80217-3364...

  2. EAC Recommendations for DOE Action Regarding Interconnection...

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

    Interconnection-Wide Planning - June 6, 2013 EAC Recommendations for DOE Action Regarding Interconnection-Wide Planning - June 6, 2013 EAC Recommendations for DOE Action Regarding ...

  3. Climate Protection Action Fund | Open Energy Information

    Open Energy Info (EERE)

    Repower America Retrieved from "http:en.openei.orgwindex.php?titleClimateProtectionActionFund&oldid767417" Categories: Organizations Political Action Committees Policy...

  4. Action Codes Table | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Action Codes Table Action codes *U.S.: **IAEA: A - Shipper's original data A B - Receiver's data accepting shipper's weights without measurement W C - Shipper's adjustment or ...

  5. Intermediate band solar cell simulation use InAs quantum dot in GaAs

    SciTech Connect (OSTI)

    Hendra P, I. B. Rahayu, F.; Sahdan, M. F.; Darma, Y.

    2015-04-16

    Intermediate band solar cell (IBSC) has become a new approach in increasing solar cell efficiency significantly. One way to create intermediate band is by proposing quantum dots (QD) technology. One of the important aspects in utilizing IBSC is the absorption of light. In this work we simulated the influence of QD arrangement in order to increase absorption coefficient and solar cell efficiency. We also simulated the influence of QD size to capture a wider light spectrum. We present a simple calculation method with low computing power demand. Results show that the increasing in quantum dot size can increase in capturing wider spectrum of light. Arrangement InAs QD in bulk material GaAs can capture wider spectrum of light and increase the absorption coefficient. The arrangement InAs QD 2 nm in GaAs bulk can increase solar cell efficiency up to 49.68%.

  6. High-Efficiency GaInP/GaAs Tandem Solar Cells

    SciTech Connect (OSTI)

    Bertness, K. A.; Friedman, D. J.; Kurtz, S. R.; Kibbler, A. E.; Cramer, C.; Olson, J. M.

    1996-09-01

    GaInP/GaAs tandem solar cells have achieved efficiencies between 25.7-30.2%, depending on illumination conditions. The efficiencies are the highest confirmed two-terminal values measured for any solar cell within each standard illumination category. The monolithic, series-connected design of the tandem cells allows them to be substituted for silicon or gallium arsenide cells in photovoltaic panel systems with minimal design changes. The advantages of using GaInP/GaAs tandem solar cells in space and terrestrial applications are discussed primarily in terms of the reduction in balance-of-system costs that accrues when using a higher efficiency cell. The new efficiency values represent a significant improvement over previous efficiencies for this materials system, and we identify grid design, back interface passivation, and top interface passivation as the three key factors leading to this improvement. In producing the high-efficiency cells, we have addressed nondestructive diagnostics and materials growth reproducibility as well as peak cell performance.

  7. High-efficiency GaInP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Bertness, K.A.; Friedman, D.J.; Kurtz, S.R.; Kibbler, A.E.; Kramer, C.; Olson, J.M.

    1994-12-01

    GaInP/GaAs tandem solar cells have achieved new record efficiencies, specifically 25.7% under air-mass 0 (AM0) illumination, 29.5% under AM 1.5 global (AM1.5G) illumination, and 30.2% at 140-180x concentration under AM 1.5 direct (AM1.5D) illumination. These values are the highest two-terminal efficiencies achieved by any solar cell under these illumination conditions. The monolithic, series-connected design of the tandem cells allows them to be substituted for silicon or gallium arsenide cells in photovoltaic panel systems with minimal design changes. The advantages of using GaInP/GaAs tandem solar cells in space and terrestrial applications are discussed primarily in terms of the reduction in balance-of-system costs that accrues when using a higher efficiency cell. The new efficiency values represent a significant improvement over previous efficiencies for this materials system, and we identify grid design, back interface passivation, and top interface passivation as the three key factors leading to this improvement. In producing the high-efficiency cells, we have addressed nondestructive diagnostics and materials growth reproducibility as well as peak cell performance. 31 refs.

  8. AlGaAs/InGaAlP tunnel junctions for multijunction solar cells

    SciTech Connect (OSTI)

    SHARPS,P.R.; LI,N.Y.; HILLS,J.S.; HOU,H.; CHANG,PING-CHIH; BACA,ALBERT G.

    2000-05-16

    Optimization of GaInP{sub 2}/GaAs dual and GaInP{sub 2}/GaAs/Ge triple junction cells, and development of future generation monolithic multi-junction cells will involve the development of suitable high bandgap tunnel junctions. There are three criteria that a tunnel junction must meet. First, the resistance of the junction must be kept low enough so that the series resistance of the overall device is not increased. For AMO, 1 sun operation, the tunnel junction resistance should be below 5 x 10{sup {minus}2} {Omega}-cm. Secondly, the peak current density for the tunnel junction must also be larger than the J{sub sc} of the cell so that the tunnel junction I-V curve does not have a deleterious effect on the I-V curve of the multi-junction device. Finally, the tunnel junction must be optically transparent, i.e., there must be a minimum of optical absorption of photons that will be collected by the underlying subcells. The paper reports the investigation of four high bandgap tunnel junctions grown by metal-organic chemical vapor deposition.

  9. TJ Solar Cell (GaInP/GaAs/Ge Ultrahigh-Efficiency Solar Cells

    SciTech Connect (OSTI)

    Friedman, Daniel

    2002-04-17

    This talk will discuss recent developments in III-V multijunction photovoltaic technology which have led to the highest-efficiency solar cells ever demonstrated. The relationship between the materials science of III-V semiconductors and the achievement of record solar cell efficiencies will be emphasized. For instance, epitaxially-grown GAInP has been found to form a spontaneously-ordered GaP/InP (111) superlattice. This ordering affects the band gap of the material, which in turn affects the design of solar cells which incorporate GaInP. For the next generation of ultrahigh-efficiency III-V solar cells, we need a new semiconductor which is lattice-matched to GaAs, has a band gap of 1 eV, and has long minority-carrier diffusion lengths. Out of a number of candidate materials, the recently-discovered alloy GaInNAs appears to have the greatest promise. This material satisfies the first two criteria, but has to date shown very low diffusion lengths, a problem which is our current focus in the development of these next-generation cells.

  10. Multijunction GaInP/GaInAs/Ge solar cells with Bragg reflectors

    SciTech Connect (OSTI)

    Emelyanov, V. M. Kalyuzhniy, N. A.; Mintairov, S. A.; Shvarts, M. Z.; Lantratov, V. M.

    2010-12-15

    Effect of subcell parameters on the efficiency of GaInP/Ga(In)As/Ge tandem solar cells irradiated with 1-MeV electrons at fluences of up to 3 x 10{sup 15} cm{sup -2} has been theoretically studied. The optimal thicknesses of GaInP and GaInAs subcells, which provide the best photocurrent matching at various irradiation doses in solar cells with and without built-in Bragg reflectors, were determined. The dependences of the photoconverter efficiency on the fluence of 1-MeV electrons and on the time of residence in the geostationary orbit were calculated for structures optimized to the beginning and end of their service lives. It is shown that the optimization of the subcell heterostructures for a rated irradiation dose and the introduction of Bragg reflectors into the structure provide a 5% overall increase in efficiency for solar cells operating in the orbit compared with unoptimized cells having no Bragg reflector.

  11. Localized corrosion of GaAs surfaces and formation of porous GaAs

    SciTech Connect (OSTI)

    Schmuki, P.; Vitus, C.M.; Isaacs, H.S.; Fraser, J.; Graham, M.J.

    1995-12-01

    The present work deals with pitting corrosion of p- and n-type GaAs (100). Pit growth can be electrochemically initiated on both conduction types in chloride-containing solutions and leads after extended periods of time to the formation of a porous GaAs structure. In the case of p-type material, localized corrosion is only observed if a passivating film is present on the surface, otherwise -- e.g. in acidic solutions -- the material suffers from a uniform attack (electropolishing) which is independent of the anion present. In contrast, pitting corrosion of n-type material can be triggered independent of the presence of an oxide film. This is explained in terms of the different current limiting factor for the differently doped materials (oxide film in the case of the p- and a space charge layer in the case of the n-GaAs). The porous structure was characterized by SEM, EDX and AES, and consists mainly of GaAs. From scratch experiments it is clear that the pit initiation process is strongly influenced by surface defects. For n-type material, AFM investigations show that light induced roughening of the order of several hundred nm occurs under non-passivating conditions. This nm- scale roughening however does not affect the pitting process.

  12. High order Chin actions in path integral Monte Carlo

    SciTech Connect (OSTI)

    Sakkos, K.; Casulleras, J.; Boronat, J.

    2009-05-28

    High order actions proposed by Chin have been used for the first time in path integral Monte Carlo simulations. Contrary to the Takahashi-Imada action, which is accurate to the fourth order only for the trace, the Chin action is fully fourth order, with the additional advantage that the leading fourth-order error coefficients are finely tunable. By optimizing two free parameters entering in the new action, we show that the time step error dependence achieved is best fitted with a sixth order law. The computational effort per bead is increased but the total number of beads is greatly reduced and the efficiency improvement with respect to the primitive approximation is approximately a factor of 10. The Chin action is tested in a one-dimensional harmonic oscillator, a H{sub 2} drop, and bulk liquid {sup 4}He. In all cases a sixth-order law is obtained with values of the number of beads that compare well with the pair action approximation in the stringent test of superfluid {sup 4}He.

  13. EA-1945: Finding of No Significant Impact and Mitigation Action Plan |

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

    Department of Energy Finding of No Significant Impact and Mitigation Action Plan EA-1945: Finding of No Significant Impact and Mitigation Action Plan Northern Mid-Columbia Joint Project; Grant, Douglas, and Chelan Counties, Washington Bonneville Power Administration (BPA) issued a finding of no significant impact, which includes a floodplain statement of findings, for the proposed Northern Mid-Columbia Joint Project, a 230-kilvolt transmission line proposed by BPA and the Public Utility

  14. The proposed Institute for Micro-manufacturing, Louisiana Tech University

    SciTech Connect (OSTI)

    Not Available

    1994-07-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA) DOE/EA-0958, evaluating the construction and equipping of two components of the proposed Institute for Micro-manufacturing at Louisiana Tech University (LTU), a proposed R and D facility to be located in Ruston, LA. and, the proposed installation of a beamline for micro-machining applications at the Center for Advanced Microstructures and Devices (CAMD) facility at Louisiana State University in Baton Rouge, LA. The objective of the proposed project is to focus on the applied, rather than basic research emphasizing the design and development, metrology, inspection and testing, and the assembly and production of micron and submicron structures and devices. Also, the objective of the beamline at CAMD would be the fundamental study of processing and analysis technologies, including x-ray lithography, which are important to microstructures fabrication and electronic device development. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required.

  15. Remedial Action Contacts Directory - 1997

    SciTech Connect (OSTI)

    1997-05-01

    This document, which was prepared for the US Department of Energy (DOE) Office of Environmental Restoration (ER), is a directory of 2628 individuals interested or involved in environmental restoration and/or remedial actions at radioactively contaminated sites. This directory contains a list of mailing addresses and phone numbers of DOE operations, area, site, project, and contractor offices; an index of DOE operations, area, site, project, and contractor office sorted by state; a list of individuals, presented by last name, facsimile number, and e-mail address; an index of affiliations presented alphabetically, with individual contacts appearing below each affiliation name; and an index of foreign contacta sorted by country and affiliation. This document was generated from the Remedial Action Contacts Database, which is maintained by the Remedial Action Program Information Center (RAPIC).

  16. fe0013961-GaTech | netl.doe.gov

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

    Performer Georgia Tech Research Corporation, Atlanta GA 30332 Background While earlier research focused on the properties of the hydrate mass per se (Sloan Jr and Koh 2007), ...

  17. Photoluminescence from GaAs nanodisks fabricated by using combination...

    Office of Scientific and Technical Information (OSTI)

    GaAs nanodisks fabricated by using combination of neutral beam etching and atomic hydrogen-assisted molecular beam epitaxy regrowth Citation Details In-Document Search Title:...

  18. Inverse spin Hall effect in Pt/(Ga,Mn)As

    SciTech Connect (OSTI)

    Nakayama, H.; Chen, L.; Chang, H. W.; Ohno, H.; Matsukura, F.

    2015-06-01

    We investigate dc voltages under ferromagnetic resonance in a Pt/(Ga,Mn)As bilayer structure. A part of the observed dc voltage is shown to originate from the inverse spin Hall effect. The sign of the inverse spin Hall voltage is the same as that in Py/Pt bilayer structure, even though the stacking order of ferromagnetic and nonmagnetic layers is opposite to each other. The spin mixing conductance at the Pt/(Ga,Mn)As interface is determined to be of the order of 10{sup 19 }m{sup −2}, which is about ten times greater than that of (Ga,Mn)As/p-GaAs.

  19. First-principles studies on molecular beam epitaxy growth of GaAs1-xBix

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

    Luo, Guangfu; Yang, Shujiang; Li, Jincheng; Arjmand, Mehrdad; Szlufarska, Izabela; Brown, April S.; Kuech, Thomas F.; Morgan, Dane

    2015-07-14

    We investigate the molecular beam epitaxy (MBE) growth of GaAs1-xBix film using density functional theory with spin-orbit coupling to understand the growth of this film, especially the mechanisms of Bi incorporation. We study the stable adsorption structures and kinetics of the incident molecules (As₂ molecule, Ga atom, Bi atom, and Bi₂ molecule) on the (2 x 1)-Gasub||Bi surface and a proposed q(1 x 1)-Gasub||AsAs surface has a quasi-(1 x 1) As layer above the Ga-terminated GaAs substrate and a randomly oriented As dimer layer on top. We obtain the desorption and diffusion barriers of the adsorbed molecules and also themore » reaction barriers of three key processes related to Bi evolution, namely, Bi incorporation, As/Bi exchange, and Bi clustering. The results help explain the experimentally observed dependence of Bi incorporation on the As/Ga ratio and growth temperature. Furthermore, we find that As₂ exchange with Bi of the (2 x 1)-Gasub||Bi surface is a key step controlling the kinetics of the Bi incorporation. Finally, we explore two possible methods to enhance the Bi incorporation, namely, replacing the MBE growth mode from codeposition of all fluxes with a sequential deposition of fluxes and applying asymmetric in-plane strain to the substrate.« less

  20. Structural and optical properties of (Ag,Cu)(In,Ga)Se{sub 2} polycrystalline thin film alloys

    SciTech Connect (OSTI)

    Boyle, J. H.; Shafarman, W. N.; Birkmire, R. W.; McCandless, B. E.

    2014-06-14

    The structural and optical properties of pentenary alloy (Ag,Cu)(In,Ga)Se{sub 2} polycrystalline thin films were characterized over the entire compositional range at a fixed (Cu + Ag)/(In + Ga) ratio. Films deposited at 550 °C on bare and molybdenum coated soda-lime glass by elemental co-evaporation in a single-stage process with constant incident fluxes exhibit single phase chalcopyrite structure, corresponding to 122 spacegroup (I-42d) over the entire compositional space. Unit cell refinement of the diffraction patterns show that increasing Ag substitution for Cu, the refined a{sub o} lattice constant, (Ag,Cu)-Se bond length, and anion displacement increase in accordance with the theoretical model proposed by Jaffe, Wei, and Zunger. However, the refined c{sub o} lattice constant and (In,Ga)-Se bond length deviated from theoretical expectations for films with mid-range Ag and Ga compositions and are attributed to influences from crystallographic bond chain ordering or cation electronegativity. The optical band gap, derived from transmission and reflection measurements, widened with increasing Ag and Ga content, due to influences from anion displacement and cation electronegativity, as expected from theoretical considerations for pseudo-binary chalcopyrite compounds.

  1. Deep level defects in n-type GaAsBi and GaAs grown at low temperatures

    SciTech Connect (OSTI)

    Mooney, P. M.; Watkins, K. P.; Jiang, Zenan; Basile, A. F.; Lewis, R. B.; Bahrami-Yekta, V.; Masnadi-Shirazi, M.; Beaton, D. A.; Tiedje, T.

    2013-04-07

    Deep level defects in n-type GaAs{sub 1-x}Bi{sub x} having 0 < x < 0.012 and GaAs grown by molecular beam epitaxy (MBE) at substrate temperatures between 300 and 400 Degree-Sign C have been investigated by Deep Level Capacitance Spectroscopy. Incorporating Bi suppresses the formation of an electron trap with activation energy 0.40 eV, thus reducing the total trap concentration in dilute GaAsBi layers by more than a factor of 20 compared to GaAs grown under the same conditions. We find that the dominant traps in dilute GaAsBi layers are defect complexes involving As{sub Ga}, as expected for MBE growth at these temperatures.

  2. Au impact on GaAs epitaxial growth on GaAs (111){sub B} substrates in molecular beam epitaxy

    SciTech Connect (OSTI)

    Liao, Zhi-Ming; Chen, Zhi-Gang; Xu, Hong-Yi; Guo, Ya-Nan; Sun, Wen; Zhang, Zhi; Yang, Lei; Lu, Zhen-Yu; Chen, Ping-Ping; Lu, Wei; Zou, Jin; Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Queensland 4072

    2013-02-11

    GaAs growth behaviour under the presence of Au nanoparticles on GaAs {l_brace}111{r_brace}{sub B} substrate is investigated using electron microscopy. It has been found that, during annealing, enhanced Ga surface diffusion towards Au nanoparticles leads to the GaAs epitaxial growth into {l_brace}113{r_brace}{sub B} faceted triangular pyramids under Au nanoparticles, governed by the thermodynamic growth, while during conventional GaAs growth, growth kinetics dominates, resulting in the flatted triangular pyramids at high temperature and the epitaxial nanowires growth at relatively low temperature. This study provides an insight of Au nanoparticle impact on GaAs growth, which is critical for understanding the formation mechanisms of semiconductor nanowires.

  3. Deep level centers and their role in photoconductivity transients of InGaAs/GaAs quantum dot chains

    SciTech Connect (OSTI)

    Kondratenko, S. V. Vakulenko, O. V.; Mazur, Yu. I. Dorogan, V. G.; Marega, E.; Benamara, M.; Ware, M. E.; Salamo, G. J.

    2014-11-21

    The in-plane photoconductivity and photoluminescence are investigated in quantum dot-chain InGaAs/GaAs heterostructures. Different photoconductivity transients resulting from spectrally selecting photoexcitation of InGaAs QDs, GaAs spacers, or EL2 centers were observed. Persistent photoconductivity was observed at 80?K after excitation of electron-hole pairs due to interband transitions in both the InGaAs QDs and the GaAs matrix. Giant optically induced quenching of in-plane conductivity driven by recharging of EL2 centers is observed in the spectral range from 0.83?eV to 1.0?eV. Conductivity loss under photoexcitation is discussed in terms of carrier localization by analogy with carrier distribution in disordered media.

  4. Isotropic Hall effect and ''freeze-in'' of carriers in the InGaAs self-assembled quantum wires

    SciTech Connect (OSTI)

    Kunets, Vas. P.; Prosandeev, S.; Mazur, Yu. I.; Ware, M. E.; Teodoro, M. D.; Dorogan, V. G.; Lytvyn, P. M.; Salamo, G. J.

    2011-10-15

    Using molecular beam epitaxy, we prepared an anisotropic media consisting of InGaAs quantum wires epitaxially grown on GaAs (311)A. Anisotropy is observed in the lateral conductivity and photoluminescence polarization. However, an isotropic Hall effect is observed in the same samples. We show that the Hall effect in this anisotropic heterostructure remains isotropic regardless of the change of the doping in GaAs barriers and regardless of the InGaAs coverage, whereas the conductivity anisotropy experiences a strong change under these actions. In addition, we observed an anomalous increase in carrier density, ''freeze-in,'' at low temperatures. In order to explain this, we generalized the theory of Look [D. C. Look, Phys. Rev B 42, 3578 (1990)] by considering the low field magneto-transport in anisotropic media. This theory confirms that the Hall constant remains isotropic in anisotropic semiconductor heterostructures, agreeing with our experiment and explains the anomalous behavior of carriers as a result of multi-band conductivity.

  5. Texas Solar Collaboration Action Plan

    SciTech Connect (OSTI)

    Winland, Chris

    2013-02-14

    Texas Solar Collaboration Permitting and Interconenction Process Improvement Action Plan. San Antonio-specific; Investigate feasibility of using electronic signatures; Investigate feasibility of enabling other online permitting processes (e.g., commercial); Assess need for future document management and workflow/notification IT improvements; Update Information Bulletin 153 regarding City requirements and processes for PV; Educate contractors and public on CPS Energy’s new 2013 solar program processes; Continue to discuss “downtown grid” interconnection issues and identify potential solutions; Consider renaming Distributed Energy Resources (DER); and Continue to participate in collaborative actions.

  6. Self-catalyzed growth of dilute nitride GaAs/GaAsSbN/GaAs core-shell nanowires by molecular beam epitaxy

    SciTech Connect (OSTI)

    Kasanaboina, Pavan Kumar; Ahmad, Estiak; Li, Jia; Iyer, Shanthi; Reynolds, C. Lewis; Liu, Yang

    2015-09-07

    Bandgap tuning up to 1.3 μm in GaAsSb based nanowires by incorporation of dilute amount of N is reported. Highly vertical GaAs/GaAsSbN/GaAs core-shell configured nanowires were grown for different N contents on Si (111) substrates using plasma assisted molecular beam epitaxy. X-ray diffraction analysis revealed close lattice matching of GaAsSbN with GaAs. Micro-photoluminescence (μ-PL) revealed red shift as well as broadening of the spectra attesting to N incorporation in the nanowires. Replication of the 4K PL spectra for several different single nanowires compared to the corresponding nanowire array suggests good compositional homogeneity amongst the nanowires. A large red shift of the Raman spectrum and associated symmetric line shape in these nanowires have been attributed to phonon localization at point defects. Transmission electron microscopy reveals the dominance of stacking faults and twins in these nanowires. The lower strain present in these dilute nitride nanowires, as opposed to GaAsSb nanowires having the same PL emission wavelength, and the observation of room temperature PL demonstrate the advantage of the dilute nitride system offers in the nanowire configuration, providing a pathway for realizing nanoscale optoelectronic devices in the telecommunication wavelength region.

  7. An inverted AlGaAs/GaAs patterned-Ge tunnel junction cascade concentrator solar cell

    SciTech Connect (OSTI)

    Venkatasubramanian, R. )

    1993-01-01

    This report describes work to develop inverted-grown Al[sub 0.34]Ga[sub 0.66]As/GaAs cascades. Several significant developments are reported on as follows: (1) The AM1.5 1-sun total-area efficiency of the top Al[sub 0.34]Ga[sub 0.66]As cell for the cascade was improved from 11.3% to 13.2% (NREL measurement [total-area]). (2) The cycled'' organometallic vapor phase epitaxy growth (OMVPE) was studied in detail utilizing a combination of characterization techniques including Hall-data, photoluminescence, and secondary ion mass spectroscopy. (3) A technique called eutectic-metal-bonding (EMB) was developed by strain-free mounting of thin GaAs-AlGaAs films (based on lattice-matched growth on Ge substrates and selective plasma etching of Ge substrates) onto Si carrier substrates. Minority-carrier lifetime in an EMB GaAs double-heterostructure was measured as high as 103 nsec, the highest lifetime report for a freestanding GaAs thin film. (4) A thin-film, inverted-grown GaAs cell with a 1-sun AM1.5 active-area efficiency of 20.3% was obtained. This cell was eutectic-metal-bonded onto Si. (5) A thin-film inverted-grown, Al[sub 0.34]Ga[sub 0.66]As/GaAs cascade with AM1.5 efficiency of 19.9% and 21% at 1-sun and 7-suns, respectively, was obtained. This represents an important milestone in the development of an AlGaAs/GaAs cascade by OMVPE utilizing a tunnel interconnect and demonstrates a proof-of-concept for the inverted-growth approach.

  8. DC characteristics of OMVPE-grown N-p-n InGaP/InGaAsN DHBTs

    SciTech Connect (OSTI)

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

    2000-01-04

    The authors demonstrate, for the first time, a functional N-p-n heterojunction bipolar transistor using a novel material, InGaAsN, with a bandgap energy of 1.2eV as the p-type base layer. A 300{angstrom}-thick In{sub x}Ga{sub 1-x}As graded layer was introduced to reduce the conduction band offset at the p-type InGaAsN base and n-type GaAs collector junction. For an emitter size of 500 {mu}m{sup 2}, a peak current gain of 5.3 has been achieved.

  9. Corrective Action Decision Document for Corrective Action Unit 562: Waste Systems Nevada Test Site, Nevada, Revision 0

    SciTech Connect (OSTI)

    Mark Krause

    2010-08-01

    action is required. Assessment of the data generated from investigation activities conducted at CAU 562 is shown in Table ES-1. Based on the evaluation of analytical data from the CAI, review of future and current operations at the 13 CASs, and the detailed and comparative analysis of the potential CAAs, the following corrective actions are recommended for CAU 562. • No further action is the preferred corrective action for CASs 02-60-01, 02-60-06, and 02-60-07. • Clean closure is the preferred corrective action for CASs 02-26-11, 02-44-02, 02-59-01, 02-60-02, 02-60-03, 02-60-04, 02-60-05, 23-60-01, 23-99-06, and 25-60-04. The preferred CAAs were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. The alternatives were judged to meet all requirements for the technical components evaluated. The alternatives meet all applicable federal and state regulations for closure of the site and will reduce potential exposures to contaminated media to acceptable levels. The DOE, National Nuclear Security Administration Nevada Site Office provides the following recommendations: • No further corrective action is required at CASs 02-60-01, 02-60-06, and 02-60-07. • Clean closure is recommended for the remaining 10 CASs in CAU 562. • A Corrective Action Plan will be submitted to the Nevada Division of Environmental Protection that contains a detailed description of the proposed actions that will be taken to implement the selected corrective actions.

  10. Reliability of AlGaN/GaN high electron mobility transistors on low dislocation density bulk GaN substrate: Implications of surface step edges

    SciTech Connect (OSTI)

    Killat, N. E-mail: Martin.Kuball@bristol.ac.uk; Montes Bajo, M.; Kuball, M. E-mail: Martin.Kuball@bristol.ac.uk; Paskova, T.; Materials Science and Engineering Department, North Carolina State University, Raleigh, North Carolina 27695 ; Evans, K. R.; Leach, J.; Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 ; Li, X.; Özgür, Ü.; Morkoç, H.; Chabak, K. D.; Crespo, A.; Gillespie, J. K.; Fitch, R.; Kossler, M.; Walker, D. E.; Trejo, M.; Via, G. D.; Blevins, J. D.

    2013-11-04

    To enable gaining insight into degradation mechanisms of AlGaN/GaN high electron mobility transistors, devices grown on a low-dislocation-density bulk-GaN substrate were studied. Gate leakage current and electroluminescence (EL) monitoring revealed a progressive appearance of EL spots during off-state stress which signify the generation of gate current leakage paths. Atomic force microscopy evidenced the formation of semiconductor surface pits at the failure location, which corresponds to the interaction region of the gate contact edge and the edges of surface steps.

  11. A monolithic white LED with an active region based on InGaN QWs separated by short-period InGaN/GaN superlattices

    SciTech Connect (OSTI)

    Tsatsulnikov, A. F. Lundin, W. V.; Sakharov, A. V.; Zavarin, E. E.; Usov, S. O.; Nikolaev, A. E.; Kryzhanovskaya, N. V.; Synitsin, M. A.; Sizov, V. S.; Zakgeim, A. L.; Mizerov, M. N.

    2010-06-15

    A new approach to development of effective monolithic white-light emitters is described based on using a short-period InGaN/GaN superlattice as a barrier layer in the active region of LED structures between InGaN quantum wells emitting in the blue and yellow-green spectral ranges. The optical properties of structures of this kind have been studied, and it is demonstrated that the use of such a superlattice makes it possible to obtain effective emission from the active region.

  12. EM International Program Action Table - June 2014 | Department...

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

    Action Table - June 2014 EM International Program Action Table - June 2014 EM International Program Action Table - June 2014 PDF icon EM International Program Action Table - June ...

  13. Guidance Regarding Actions That May Proceed During the NEPA Process...

    Office of Environmental Management (EM)

    Actions That May Proceed During the NEPA Process: Interim Actions Guidance Regarding Actions That May Proceed During the NEPA Process: Interim Actions DOE guidance to provide...

  14. Environmental Assessment of Remedial Action at the Riverton Uranium Mill Tailings Site, Riverton, Wyoming

    SciTech Connect (OSTI)

    1987-06-01

    The US Department of Energy (DOE) has prepared an environmental assessment (DOE/EA-0254) on the proposed remedial action at the inactive uranium milling site near Riverton, Wyoming. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321, et seq.). Therefore, the preparation of an environmental impact statement (EIS) is not required.

  15. Action

    National Nuclear Security Administration (NNSA)

    ... personal belongings will be subject to a physical search. ... have the ability to enter into payment for order flow ... parameters, the specific terms governing the orders that ...

  16. Climate Action Champions | Department of Energy

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

    Initiatives » Climate Action Champions Climate Action Champions Climate Action Champions The White House launched the Climate Action Champions (CAC) Initiative in December 2014 with the U.S. Department of Energy (DOE) as lead Agency. The Administration expanded the Initiative in December 2015 through a strategic partnership with the Corporation for National Community Service (CNCS). PROGRAM POLICY OBJECTIVES The Climate Action Champions Initiative supports local and tribal government climate

  17. Photoeffects in WO{sub 3}/GaAs electrode

    SciTech Connect (OSTI)

    Yoon, K.H.; Lee, J.W.; Cho, Y.S.; Kang, D.H.

    1996-12-01

    Photoeffects of a {ital p}-type GaAs coated with WO{sub 3} thin film have been investigated as a function of film thickness and photoresponse transients of the WO{sub 3}/GaAs electrode were studied. Also, these results were compared to those for a single {ital p}-type GaAs electrode. The photocurrent of the WO{sub 3}/GaAs electrode depended on the film thickness of the WO{sub 3}, showing an optimum photon efficiency for specimens of 800 A thickness. This is due to the existence of an effective interface state within the band gap which reduces trapping of carriers and facilitates carrier movement. For an 800-A-thick WO{sub 3} thin film deposited {ital p}-GaAs photoelectrode, the photogenerated electrons were found to move to an electrolyte at a higher positive onset potential compared with that of single {ital p}-type GaAs, which was confirmed as a result of transient behavior. {ital I}{endash}{ital V} and {ital C}{endash}{ital V} characteristics of the WO{sub 3}/GaAs electrode were also compared with those of a single {ital p}-type GaAs electrode. {copyright} {ital 1996 American Institute of Physics.}

  18. Category:Proposed deletion | Open Energy Information

    Open Energy Info (EERE)

    History Category:Proposed deletion Jump to: navigation, search This category contains articles which have been proposed for deletion. To tag an article for proposed deletion use...

  19. proposed surface and subsurface marker designs

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

    Images of proposed markers for the surface and subsurface Large Surface Marker - Proposed Design with Plaques of Text and Images Small Subsurface Marker - Proposed Design

  20. Research Proposal Milestones | Department of Energy

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

    Proposal Milestones Research Proposal Milestones Research Proposal Milestones, from the U.S. Department of Energy's Postdoctoral Research Awards program. templateformilestones.xl...

  1. Long-wavelength shift and enhanced room temperature photoluminescence efficiency in GaAsSb/InGaAs/GaAs-based heterostructures emitting in the spectral range of 1.01.2??m due to increased charge carrier's localization

    SciTech Connect (OSTI)

    Kryzhkov, D. I. Yablonsky, A. N.; Morozov, S. V.; Aleshkin, V. Ya.; Krasilnik, Z. F.; Zvonkov, B. N.; Vikhrova, O. V.

    2014-11-28

    In this work, a study of the photoluminescence (PL) temperature dependence in quantum well GaAs/GaAsSb and double quantum well InGaAs/GaAsSb/GaAs heterostructures grown by metalorganic chemical vapor deposition with different parameters of GaAsSb and InGaAs layers has been performed. It has been demonstrated that in double quantum well InGaAs/GaAsSb/GaAs heterostructures, a significant shift of the PL peak to a longer-wavelength region (up to 1.2??m) and a considerable reduction in the PL thermal quenching in comparison with GaAs/GaAsSb structures can be obtained due to better localization of charge carriers in the double quantum well. For InGaAs/GaAsSb/GaAs heterostructures, an additional channel of radiative recombination with participation of the excited energy states in the quantum well, competing with the main ground-state radiative transition, has been revealed.

  2. Growth of GaN@InGaN Core-Shell and Au-GaN Hybrid Nanostructures for Energy Applications

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

    Kuykendall, Tevye; Aloni, Shaul; Jen-La Plante, Ilan; Mokari, Taleb

    2009-01-01

    We demonstrated a method to control the bandgap energy of GaN nanowires by forming GaN@InGaN core-shell hybrid structures using metal organic chemical vapor deposition (MOCVD). Furthermore, we show the growth of Au nanoparticles on the surface of GaN nanowires in solution at room temperature. The work shown here is a first step toward engineering properties that are crucial for the rational design and synthesis of a new class of photocatalytic materials. The hybrid structures were characterized by various techniques, including photoluminescence (PL), energy dispersive x-ray spectroscopy (EDS), transmission and scanning electron microscopy (TEM and SEM), and x-ray diffraction (XRD).

  3. Raman spectroscopy of GaP/GaNP core/shell nanowires

    SciTech Connect (OSTI)

    Dobrovolsky, A.; Chen, W. M.; Buyanova, I. A.; Sukrittanon, S.; Kuang, Y. J.; Tu, C. W.

    2014-11-10

    Raman spectroscopy is employed to characterize structural and phonon properties of GaP/GaNP core/shell nanowires (NWs) grown by molecular beam epitaxy on Si substrates. According to polarization-dependent measurements performed on single NWs, the dominant Raman modes associated with zone-center optical phonons obey selection rules in a zinc-blende lattice, confirming high crystalline quality of the NWs. Two additional modes at 360 and 397 cm{sup −1} that are specific to the NW architecture are also detected in resonant Raman spectra and are attributed to defect-activated scattering involving zone-edge transverse optical phonons and surface optical phonons, respectively. It is concluded that the formation of the involved defect states are mainly promoted during the NW growth with a high V/III ratio.

  4. Room temperature spin transport in undoped (110) GaAs/AlGaAs quantum wells

    SciTech Connect (OSTI)

    Yokota, Nobuhide Aoshima, Yohei; Ikeda, Kazuhiro; Kawaguchi, Hitoshi

    2014-02-17

    We are reporting on our first observation of a micrometer-order electron spin transport in a (110) GaAs/AlGaAs multiple quantum well (QW) at room temperature using a space- and time-resolved Kerr rotation technique. A 37-μm transport was observed within an electron spin lifetime of 1.2 ns at room temperature when using an in-plane electric field of 1.75 kV/cm. The spatio-temporal profiles of electron spins were well reproduced by the spin drift-diffusion equations coupled with the Poisson equation, supporting the validity of the measurement. The results suggest that (110) QWs are useful as a spin transport layer for semiconductor spintronic devices operating at room temperature.

  5. Large linear magnetoresistance in a GaAs/AlGaAs heterostructure

    SciTech Connect (OSTI)

    Aamir, Mohammed Ali Goswami, Srijit Ghosh, Arindam; Baenninger, Matthias; Farrer, Ian; Ritchie, David A.; Tripathi, Vikram; Pepper, Michael

    2013-12-04

    We report non-saturating linear magnetoresistance (MR) in a two-dimensional electron system (2DES) at a GaAs/AlGaAs heterointerface in the strongly insulating regime. We achieve this by driving the gate voltage below the pinch-off point of the device and operating it in the non-equilibrium regime with high source-drain bias. Remarkably, the magnitude of MR is as large as 500% per Tesla with respect to resistance at zero magnetic field, thus dwarfing most non-magnetic materials which exhibit this linearity. Its primary advantage over most other materials is that both linearity and the enormous magnitude are retained over a broad temperature range (0.3 K to 10 K), thus making it an attractive candidate for cryogenic sensor applications.

  6. Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings

    SciTech Connect (OSTI)

    Wagener, M. C.; Botha, J. R.; Carrington, P. J.; Krier, A.

    2014-07-28

    The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudo-monochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo- and thermal-emission characteristics of the quantum rings.

  7. Sidewall passivation for InGaN/GaN nanopillar light emitting diodes

    SciTech Connect (OSTI)

    Choi, Won Hyuck; Abraham, Michael; Yu, Shih-Ying [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); You, Guanjun; Liu, Jie; Wang, Li; Xu, Jian, E-mail: jianxu@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Mohney, Suzanne E., E-mail: mohney@ems.psu.edu [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-07-07

    We studied the effect of sidewall passivation on InGaN/GaN multiquantum well-based nanopillar light emitting diode (LED) performance. In this research, the effects of varying etch rate, KOH treatment, and sulfur passivation were studied for reducing nanopillar sidewall damage and improving device efficiency. Nanopillars prepared under optimal etching conditions showed higher photoluminescence intensity compared with starting planar epilayers. Furthermore, nanopillar LEDs with and without sulfur passivation were compared through electrical and optical characterization. Suppressed leakage current under reverse bias and four times higher electroluminescence (EL) intensity were observed for passivated nanopillar LEDs compared with unpassivated nanopillar LEDs. The suppressed leakage current and EL intensity enhancement reflect the reduction of non-radiative recombination at the nanopillar sidewalls. In addition, the effect of sulfur passivation was found to be very stable, and further insight into its mechanism was gained through transmission electron microscopy.

  8. Ultrafast dynamics of type-II GaSb/GaAs quantum dots

    SciTech Connect (OSTI)

    Komolibus, K.; Piwonski, T.; Gradkowski, K.; Reyner, C. J.; Liang, B.; Huffaker, D. L.; Huyet, G.; Houlihan, J.

    2015-01-19

    In this paper, room temperature two-colour pump-probe spectroscopy is employed to study ultrafast carrier dynamics in type-II GaSb/GaAs quantum dots. Our results demonstrate a strong dependency of carrier capture/escape processes on applied reverse bias voltage, probing wavelength and number of injected carriers. The extracted timescales as a function of both forward and reverse bias may provide important information for the design of efficient solar cells and quantum dot memories based on this material. The first few picoseconds of the dynamics reveal a complex behaviour with an interesting feature, which does not appear in devices based on type-I materials, and hence is linked to the unique carrier capture/escape processes possible in type-II structures.

  9. Elastic properties of Pu metal and Pu-Ga alloys

    SciTech Connect (OSTI)

    Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A

    2010-01-05

    We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga ({delta}) alloys together with ab initio equilibrium equation-of-state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from {alpha} {yields} {beta} {yields} {gamma} plutonium, thus suggesting increasing f-electron correlation (localization). For the {delta}-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants, suggest a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.

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

    SciTech Connect (OSTI)

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

    2010-09-01

    concert with sophisticated molecular-dynamics calculations of surface and defect-mediated NW thermal transport. This proposal seeks to elucidate long standing material science questions for GaN while addressing issues critical to realizing reliable GaN NW devices.

  11. Germanium subcells for multijunction GaInP/GaInAs/Ge solar cells

    SciTech Connect (OSTI)

    Kalyuzhnyy, N. A.; Gudovskikh, A. S.; Evstropov, V. V.; Lantratov, V. M.; Mintairov, S. A.; Timoshina, N. Kh.; Shvarts, M. Z.; Andreev, V. M.

    2010-11-15

    Photovoltaic converters based on n-GaInP/n-p-Ge heterostructures grown by the OMVPE under different conditions of formation of the p-n junction are studied. The heterostructures are intended for use as narrow-gap subcells of the GaInP/GaInAs/Ge three-junction solar cells. It is shown that, in Ge p-tn junctions, along with the diffusion mechanism, the tunneling mechanism of the current flow exists; therefore, the two-diode electrical equivalent circuit of the Ge p-n junction is used. The diode parameters are determined for both mechanisms from the analysis of both dark and 'light' current-voltage dependences. It is shown that the elimination of the component of the tunneling current allows one to increase the efficiency of the Ge subcell by {approx}1% with conversion of nonconcentrated solar radiation. The influence of the tunneling current on the efficiency of the Ge-based devices can be in practice reduced to zero at photogenerated current density of {approx}1.5 A/cm{sup 2} due to the use of the concentrated solar radiation.

  12. Thermal Design and Characterization of Heterogeneously Integrated InGaP/GaAs HBTs

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

    Choi, Sukwon; Peake, Gregory M.; Keeler, Gordon A.; Geib, Kent M.; Briggs, Ronald D.; Beechem, Thomas E.; Shaffer, Ryan A.; Clevenger, Jascinda; Patrizi, Gary A.; Klem, John F.; et al

    2016-04-21

    Flip-chip heterogeneously integrated n-p-n InGaP/GaAs heterojunction bipolar transistors (HBTs) with integrated thermal management on wide-bandgap AlN substrates followed by GaAs substrate removal are demonstrated. Without thermal management, substrate removal after integration significantly aggravates self-heating effects, causing poor I–V characteristics due to excessive device self-heating. An electrothermal codesign scheme is demonstrated that involves simulation (design), thermal characterization, fabrication, and evaluation. Thermoreflectance thermal imaging, electrical-temperature sensitive parameter-based thermometry, and infrared thermography were utilized to assess the junction temperature rise in HBTs under diverse configurations. In order to reduce the thermal resistance of integrated devices, passive cooling schemes assisted by structural modification, i.e.,more » positioning indium bump heat sinks between the devices and the carrier, were employed. By implementing thermal heat sinks in close proximity to the active region of flip-chip integrated HBTs, the junction-to-baseplate thermal resistance was reduced over a factor of two, as revealed by junction temperature measurements and improvement of electrical performance. In conclusion, the suggested heterogeneous integration method accounts for not only electrical but also thermal requirements providing insight into realization of advanced and robust III–V/Si heterogeneously integrated electronics.« less

  13. Transport properties of InGaAs/GaAs Heterostructures with {delta}-doped quantum wells

    SciTech Connect (OSTI)

    Baidus, N. V.; Vainberg, V. V.; Zvonkov, B. N.; Pylypchuk, A. S. Poroshin, V. N.; Sarbey, O. G.

    2012-05-15

    The lateral transport of electrons in single- and double-well pseudomorphic GaAs/n-InGaAs/GaAs heterostructures with quantum wells 50-100 meV deep and impurity {delta}-layers in the wells, with concentrations in the range 10{sup 11} < N{sub s} < 10{sup 12} cm{sup -2}, has been investigated. Single-well structures with a doped well at the center exhibit a nonmonotonic temperature dependence of the Hall coefficient and an increase in low-temperature electron mobility with an increase in the impurity concentration. The results obtained indicate that the impurity-band electron states play an important role in the conductivity of these structures. Involvement of the impurity band also allows to explain adequately the characteristics of the conductivity of double-well structures; in contrast to single-well structures, band bending caused by asymmetric doping is of great importance. The numerical calculations of conductivity within the model under consideration confirm these suggestions.

  14. Effect of catalyst diameter on vapour-liquid-solid growth of GaAs nanowires

    SciTech Connect (OSTI)

    O'Dowd, B. J. Shvets, I. V.; Wojtowicz, T.; Kolkovsky, V.; Wojciechowski, T.; Zgirski, M.; Rouvimov, S.; Liu, X.; Pimpinella, R.; Dobrowolska, M.; Furdyna, J.

    2014-08-14

    GaAs nanowires were grown on (111)B GaAs substrates using the vapour-liquid-solid mechanism. The Au/Pt nanodots used to catalyse wire growth were defined lithographically and had varying diameter and separation. An in-depth statistical analysis of the resulting nanowires, which had a cone-like shape, was carried out. This revealed that there were two categories of nanowire present, with differing height and tapering angle. The bimodal nature of wire shape was found to depend critically on the diameter of the Au-Ga droplet atop the nanowire. Transmission electron microscopy analysis also revealed that the density of stacking faults in the wires varied considerably between the two categories of wire. It is believed that the cause of the distinction in terms of shape and crystal structure is related to the contact angle between the droplet and the solid-liquid interface. The dependency of droplet diameter on contact angle is likely related to line-tension, which is a correction to Young's equation for the contact angle of a droplet upon a surface. The fact that contact angle may influence resulting wire structure and shape has important implications for the planning of growth conditions and the preparation of wires for use in proposed devices.

  15. Optical properties of multi-stacked InGaAs/GaNAs quantum dot solar cell fabricated on GaAs (311)B substrate

    SciTech Connect (OSTI)

    Shoji, Yasushi; Akimoto, Katsuhiro; Okada, Yoshitaka

    2012-09-15

    Quantum dot solar cells (QDSCs) comprised of 10 stacked pairs of strain-compensated InGaAs/GaNAs QD structure have been fabricated by atomic hydrogen-assisted molecular beam epitaxy. A homogeneous and high-density QD array structure with improved in-plane ordering and total density of {approx}10{sup 12} cm{sup -2} has been achieved on GaAs (311)B grown at 460 Degree-Sign C after stacking. The external quantum efficiency (EQE) of InGaAs/GaNAs QDSC increases in the longer wavelength range due to additive contribution from QD layers inserted in the intrinsic region. The short-circuit current density measured for QDSC is 17.2 mA/cm{sup 2} compared to 14.8 mA/cm{sup 2} of GaAs reference cell. Further, an increase in EQE due to photocurrent production by 2-step photon absorption has been observed at room temperature though it is still small at around 0.1%.

  16. Reactive codoping of GaAlInP compound semiconductors (Patent...

    Office of Scientific and Technical Information (OSTI)

    Patent: Reactive codoping of GaAlInP compound semiconductors Citation Details In-Document Search Title: Reactive codoping of GaAlInP compound semiconductors A GaAlInP compound ...

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

    Office of Scientific and Technical Information (OSTI)

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

  18. General Atomics (GA) Fusion News: A New Spin on Understanding Plasma

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

    Confinement | Princeton Plasma Physics Lab General Atomics (GA) Fusion News: A New Spin on Understanding Plasma Confinement American Fusion News Category: General Atomics (GA) Link: General Atomics (GA) Fusion News: A New Spin on Understanding Plasma Confinement

  19. Generation and control of spin-polarized photocurrents in GaMnAs heterostructures

    SciTech Connect (OSTI)

    Bezerra, Anibal T. Farinas, Paulo F.; Studart, Nelson; Degani, Marcos H.; Maialle, Marcelo Z.

    2014-01-13

    Photocurrents are calculated for a specially designed GaMnAs semiconductor heterostructure. The results reveal regions in the infrared range of the energy spectrum, in which the proposed structure is remarkably spin-selective. For such photon energies, the generated photocurrents are strongly spin-polarized. Application of a relatively small static bias in the growth direction of the structure is predicted to efficiently reverse the spin-polarization for some photon energies. This behavior suggests the possibility of conveniently simple switching mechanisms. The physics underlying the results is studied and understood in terms of the spin-dependent properties emerging from the particular potential profile of the structure.

  20. Proposal Review Panel | Stanford Synchrotron Radiation Lightsource

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

    Proposal Review Panel Submitting a proposal is the first step to access beam time at SSRL. Proposals are peer reviewed and rated by the SSRL Proposal Review Panel (PRP) on a scale ...

  1. Action Sheet 36 Final Report

    SciTech Connect (OSTI)

    Kips, R E; Kristo, M J; Hutcheon, I D

    2012-02-24

    Pursuant to the Arrangement between the European Commission DG Joint Research Centre (EC-JRC) and the Department of Energy (DOE) to continue cooperation on research, development, testing, and evaluation of technology, equipment, and procedures in order to improve nuclear material control, accountancy, verification, physical protection, and advanced containment and surveillance technologies for international safeguards, dated 1 September 2008, the IRMM and LLNL established cooperation in a program on the Study of Chemical Changes in Uranium Oxyfluoride Particles under IRMM-LLNL Action Sheet 36. The work under this action sheet had 2 objectives: (1) Achieve a better understanding of the loss of fluorine in UO{sub 2}F{sub 2} particles after exposure to certain environmental conditions; and (2) Provide feedback to the EC-JRC on sample reproducibility and characteristics.

  2. Holography of gravitational action functionals

    SciTech Connect (OSTI)

    Mukhopadhyay, Ayan; Padmanabhan, T.

    2006-12-15

    Einstein-Hilbert (EH) action can be separated into a bulk and a surface term, with a specific ('holographic') relationship between the two, so that either can be used to extract information about the other. The surface term can also be interpreted as the entropy of the horizon in a wide class of spacetimes. Since EH action is likely to just the first term in the derivative expansion of an effective theory, it is interesting to ask whether these features continue to hold for more general gravitational actions. We provide a comprehensive analysis of Lagrangians of the form {radical}(-g)L={radical}(-g)Q{sub a}{sup bcd}R{sup a}{sub bcd}, in which Q{sub a}{sup bcd} is a tensor with the symmetries of the curvature tensor, made from metric and curvature tensor and satisfies the condition {nabla}{sub c}Q{sub a}{sup bcd}=0, and show that they share these features. The Lanczos-Lovelock Lagrangians are a subset of these in which Q{sub a}{sup bcd} is a homogeneous function of the curvature tensor. They are all holographic, in a specific sense of the term, and--in all these cases--the surface term can be interpreted as the horizon entropy. The thermodynamics route to gravity, in which the field equations are interpreted as TdS=dE+pdV, seems to have a greater degree of validity than the field equations of Einstein gravity itself. The results suggest that the holographic feature of EH action could also serve as a new symmetry principle in constraining the semiclassical corrections to Einstein gravity. The implications are discussed.

  3. Take the Energy Action Challenge

    K-12 Energy Lesson Plans and Activities Web site (EERE)

    Students will work in pairs or small groups to apply knowledge of energy-wise habits to evaluate energy use in their homes and schools and make recommendations for improved efficiency. They will use an energy audit tool to collect data on their home and school energy habits and present an action plan to their class. Further communication at the school and district level is encouraged.

  4. Defect reduction in epitaxial GaSb grown on nanopatterned GaAs substrates using full wafer block copolymer lithography

    SciTech Connect (OSTI)

    Jha, Smita; Liu, C.-C.; Nealey, P. F.; Kuech, T. F.; Kuan, T. S.; Babcock, S. E.; Park, J. H.; Mawst, L. J.

    2009-08-10

    Defect reduction in the large lattice mismatched system of GaSb on GaAs, {approx}7%, was accomplished using full wafer block copolymer (BCP) lithography. A self-assembled BCP mask layer was used to generate a hexagonal pattern of {approx}20 nm holes on {approx}40 nm centers in a 20 nm SiO{sub 2} layer. GaSb growth initially takes place selectively within these holes leading to a dense array of small, strain-relaxed epitaxial GaSb islands. The GaSb grown on the patterned SiO{sub 2} layer exhibits a reduction in the x-ray linewidth attributed to a decrease in the threading dislocation density when compared to blanket pseudomorphic film growth.

  5. Structural and emission properties of InGaAs/GaAs quantum dots emitting at 1.3??m

    SciTech Connect (OSTI)

    Goldmann, Elias Jahnke, Frank; Paul, Matthias; Kettler, Jan; Jetter, Michael; Michler, Peter; Krause, Florian F.; Mller, Knut; Mehrtens, Thorsten; Rosenauer, Andreas

    2014-10-13

    A combined experimental and theoretical study of InGaAs/GaAs quantum dots (QDs) emitting at 1.3??m under the influence of a strain-reducing InGaAs quantum well is presented. We demonstrate a red shift of 2040?nm observed in photoluminescence spectra due to the quantum well. The InGaAs/GaAs QDs grown by metal organic vapor phase epitaxy show a bimodal height distribution (1?nm and 5?nm) and indium concentrations up to 90%. The emission properties are explained with combined tight-binding and configuration-interaction calculations of the emission wavelengths in conjunction with high-resolution scanning transmission electron microscopy investigations of QD geometry and indium concentrations in the QDs, which directly enter the calculations. QD geometries and concentration gradients representative for the ensemble are identified.

  6. Progress toward technology transition of GaInP{sub 2}/GaAs/Ge multijunction solar cells

    SciTech Connect (OSTI)

    Keener, D.N.; Marvin, D.C.; Brinker, D.J.; Curtis, H.B.; Price, P.M.

    1997-12-31

    The objective of the joint WL/PL/NASA Multijunction Solar Cell Manufacturing Technology (ManTech) Program is to scale up high efficiency GaInP{sub 2}/GaAs/Ge multijunction solar cells to production size, quantity, and yield while limiting the production cost/Watt ($/W) to 15% over GaAs cells. Progress made by the program contractors, Spectrolab and TECSTAR, include, respectively, best cell efficiencies of 25.76% and 24.7% and establishment of 24.2% and 23.8% lot average efficiency baseline designs. The paper also presents side-by-side testing results collected by Phillips Laboratory and NASA Lewis on Phase 1 deliverable cells, which shows compliance with program objectives. Cell performance, pre- and post-radiation, and temperature coefficient results on initial production GaInP{sub 2}/GaAs/Ge solar cells will be presented.

  7. Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

    SciTech Connect (OSTI)

    Calciati, Marco; Vallone, Marco; Zhou, Xiangyu; Ghione, Giovanni; Goano, Michele Bertazzi, Francesco; Meneghini, Matteo; Meneghesso, Gaudenzio; Zanoni, Enrico; Verzellesi, Giovanni; Zhu, Dandan; Humphreys, Colin

    2014-06-15

    Electroluminescence (EL) characterization of InGaN/GaN light-emitting diodes (LEDs), coupled with numerical device models of different sophistication, is routinely adopted not only to establish correlations between device efficiency and structural features, but also to make inferences about the loss mechanisms responsible for LED efficiency droop at high driving currents. The limits of this investigative approach are discussed here in a case study based on a comprehensive set of current- and temperature-dependent EL data from blue LEDs with low and high densities of threading dislocations (TDs). First, the effects limiting the applicability of simpler (closed-form and/or one-dimensional) classes of models are addressed, like lateral current crowding, vertical carrier distribution nonuniformity, and interband transition broadening. Then, the major sources of uncertainty affecting state-of-the-art numerical device simulation are reviewed and discussed, including (i) the approximations in the transport description through the multi-quantum-well active region, (ii) the alternative valence band parametrizations proposed to calculate the spontaneous emission rate, (iii) the difficulties in defining the Auger coefficients due to inadequacies in the microscopic quantum well description and the possible presence of extra, non-Auger high-current-density recombination mechanisms and/or Auger-induced leakage. In the case of the present LED structures, the application of three-dimensional numerical-simulation-based analysis to the EL data leads to an explanation of efficiency droop in terms of TD-related and Auger-like nonradiative losses, with a C coefficient in the 10{sup −30} cm{sup 6}/s range at room temperature, close to the larger theoretical calculations reported so far. However, a study of the combined effects of structural and model uncertainties suggests that the C values thus determined could be overestimated by about an order of magnitude. This preliminary

  8. Allocation Proposal (ERCAP) Application Deadlines

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

    Application Deadlines Allocation Proposal (ERCAP) Application Deadlines Award Type ERCAP Submission Open ERCAP Submission Deadline Award Decision Allocation Period Startup and Education Ongoing November 10, 2016 Within 3 weeks of applying 18 months from award (but must be renewed for the next allocation year) Production (DOE awarded) for the rest of allocation year (AY) 2016 Ongoing November 10, 2016 Within 4 weeks of applying (pending sufficient DOE reserves of time) through January 9, 2017 All

  9. Ultra-thin GaAs single-junction solar cells integrated with a reflective back scattering layer

    SciTech Connect (OSTI)

    Yang, Weiquan; Becker, Jacob; Liu, Shi; Kuo, Ying-Shen; Li, Jing-Jing; Zhang, Yong-Hang; Landini, Barbara; Campman, Ken

    2014-05-28

    This paper reports the proposal, design, and demonstration of ultra-thin GaAs single-junction solar cells integrated with a reflective back scattering layer to optimize light management and minimize non-radiative recombination. According to our recently developed semi-analytical model, this design offers one of the highest potential achievable efficiencies for GaAs solar cells possessing typical non-radiative recombination rates found among commercially available III-V arsenide and phosphide materials. The structure of the demonstrated solar cells consists of an In{sub 0.49}Ga{sub 0.51}P/GaAs/In{sub 0.49}Ga{sub 0.51}P double-heterostructure PN junction with an ultra-thin 300?nm thick GaAs absorber, combined with a 5??m thick Al{sub 0.52}In{sub 0.48}P layer with a textured as-grown surface coated with Au used as a reflective back scattering layer. The final devices were fabricated using a substrate-removal and flip-chip bonding process. Solar cells with a top metal contact coverage of 9.7%, and a MgF{sub 2}/ZnS anti-reflective coating demonstrated open-circuit voltages (V{sub oc}) up to 1.00?V, short-circuit current densities (J{sub sc}) up to 24.5?mA/cm{sup 2}, and power conversion efficiencies up to 19.1%; demonstrating the feasibility of this design approach. If a commonly used 2% metal grid coverage is assumed, the anticipated J{sub sc} and conversion efficiency of these devices are expected to reach 26.6?mA/cm{sup 2} and 20.7%, respectively.

  10. Portsmouth Removal Actions | Department of Energy

    Energy Savers [EERE]

    Removal Actions Portsmouth Removal Actions Links to the Portsmouth Removal Action Reports in PDF. Final Action Memorandum for the Plant Support Buildings and Structures at Portsmouth - March 2012 (6.98 MB) Removal Action Completion Report for Phases I and II of X-334 Transformer Cleaning/Storage Building at Portsmouth - Nov 2011 (4.75 MB) Removal Action Completion Report for X-103 Auxiliary Office Building at Portsmouth - Nov 2011 (4.1 MB) Construction Completion Report for Phases I and II of

  11. CORRECTIVE ACTION PLAN FOR CORRECTIVE ACTION UNIT 543: LIQUID DISPOSAL UNITS, NEVADA TEST SITE, NEVADA

    SciTech Connect (OSTI)

    2006-09-01

    The purpose of this Corrective Action Plan is to provide the detailed scope of work required to implement the recommended corrective actions as specified in the approved Corrective Action Decision Document.

  12. Effect of InGaAs interlayer on the properties of GaAs grown on Si (111) substrate by molecular beam epitaxy

    SciTech Connect (OSTI)

    Wen, Lei; Gao, Fangliang; Li, Jingling; Guan, Yunfang; Wang, Wenliang; Zhou, Shizhong; Lin, Zhiting; Zhang, Xiaona; Zhang, Shuguang E-mail: mssgzhang@scut.edu.cn; Li, Guoqiang E-mail: mssgzhang@scut.edu.cn

    2014-11-21

    High-quality GaAs films have been epitaxially grown on Si (111) substrates by inserting an In{sub x}Ga{sub 1−x}As interlayer with proper In composition by molecular beam epitaxy (MBE). The effect of In{sub x}Ga{sub 1−x}As (0 < x < 0.2) interlayers on the properties of GaAs films grown on Si (111) substrates by MBE has been studied in detailed. Due to the high compressive strain between InGaAs and Si, InGaAs undergoes partial strain relaxation. Unstrained InGaAs has a larger lattice constant than GaAs. Therefore, a thin InGaAs layer with proper In composition may adopt a close lattice constant with that of GaAs, which is beneficial to the growth of high-quality GaAs epilayer on top. It is found that the proper In composition in In{sub x}Ga{sub 1−x}As interlayer of 10% is beneficial to obtaining high-quality GaAs films, which, on the one hand, greatly compensates the misfit stress between GaAs film and Si substrate, and on the other hand, suppresses the formation of multiple twin during the heteroepitaxial growth of GaAs film. However, when the In composition does not reach the proper value (∼10%), the In{sub x}Ga{sub 1−x}As adopts a lower strain relaxation and undergoes a lattice constant smaller than unstrained GaAs, and therefore introduces compressive stress to GaAs grown on top. When In composition exceeds the proper value, the In{sub x}Ga{sub 1−x}As will adopt a higher strain relaxation and undergoes a lattice constant larger than unstrained GaAs, and therefore introduces tensile stress to GaAs grown on top. As a result, In{sub x}Ga{sub 1−x}As interlayers with improper In composition introduces enlarged misfit stress to GaAs epilayers grown on top, and deteriorates the quality of GaAs epilayers. This work demonstrates a simple but effective method to grow high-quality GaAs epilayers and brings up a broad prospect for the application of GaAs-based optoelectronic devices on Si substrates.

  13. Novel attributes in modeling and optimizing of the new graphene based In{sub x}Ga{sub 1?x}N Schottky barrier solar cells

    SciTech Connect (OSTI)

    Arefinia, Zahra [Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz 51666-14766 (Iran, Islamic Republic of); Asgari, Asghar, E-mail: asgari@tabrizu.ac.ir [Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz 51666-14766 (Iran, Islamic Republic of); School of Electrical, Electronic, and Computer Engineering, University of Western Australia, Crawley, WA 6009 (Australia)

    2014-05-21

    Based on the ability of In{sub x}Ga{sub 1?x}N materials to optimally span the solar spectrum and their superior radiation resistance, solar cells based on p-type In{sub x}Ga{sub 1?x}N with low indium contents and interfacing with graphene film (G/In{sub x}Ga{sub 1?x}N), is proposed to exploit the benefit of transparency and work function tunability of graphene. Then, their solar power conversion efficiency modeled and optimized using a new analytical approach taking into account all recombination processes and accurate carrier mobility. Furthermore, their performance was compared with graphene on silicon counterparts and G/p-In{sub x}Ga{sub 1?x}N showed relatively smaller short-circuits current (?7?mA/cm{sup 2}) and significantly higher open-circuit voltage (?4?V) and efficiency (?30%). The thickness, doping concentration, and indium contents of p-In{sub x}Ga{sub 1?x}N and graphene work function were found to substantially affect the performance of G/p-In{sub x}Ga{sub 1?x}N.

  14. Environmental Assessment and FONSI Proposed Decontamination and Disassembly of the Argonne Thermal Source Reactor (ATSR) at Argonne National Laboratory

    SciTech Connect (OSTI)

    N /A

    1998-07-15

    The purpose of this project is to protect human health and the environment from risks associated with the contaminated surplus ATSR. The proposed action is needed because the ATSR, a former experimental reactor, contains residual radioactivity and hazardous materials.

  15. Comparison of the degradation characteristics of AlON/InGaAs and Al{sub 2}O{sub 3}/InGaAs stacks

    SciTech Connect (OSTI)

    Palumbo, F. Krylov, I.; Eizenberg, M.

    2015-03-14

    In this paper, the degradation characteristics of MOS (Metal-Oxide-Semiconductor) stacks with Al{sub 2}O{sub 3}/AlON or Al{sub 2}O{sub 3} only as dielectric layers on InGaAs were studied. The dielectric nitrides are proposed as possible passivation layers to prevent InGaAs oxidation. At negative bias, it has been found out that the main contribution to the overall degradation of the gate oxide is dominated by the generation of positive charge in the gate oxide. This effect is pronounced in MOS stacks with Al{sub 2}O{sub 3}/AlON as dielectric, where we think the positive charge is mainly generated in the AlON interlayer. At positive bias, the degradation is dominated by buildup of negative charge due to electron trapping in pre-existing or stress-induced traps. For stress biases where the leakage currents are low, the changes in the electrical characteristics are dominated by electron-trapping into traps located in energy levels in the upper part of the semiconductor gap. For stress biases with higher leakage current levels, the electron trapping occurs in stress-induced traps increasing the shift of V{sub FB} towards positive bias. The overall results clearly show that the improvement of the high-k dielectric/InGaAs interface by introducing N into the Al-oxide does not necessarily mean an increase in the reliability of the MOS stack.

  16. Ferromagnetism in undoped One-dimensional GaN Nanowires

    SciTech Connect (OSTI)

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

    2014-05-15

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

  17. Characterization of Zns-GaP Naon-composites

    SciTech Connect (OSTI)

    Todd, V.

    1993-12-09

    It proved possible to produce consistent, high-quality nanocrystalline ZnS powders with grain sizes as small as 8 nm. These powders are nano-porous and are readily impregnated with GaP precursor, although inconsistently. Both crystal structure and small grain size of the ZnS can be maintained through the use of GaP. Heat treatment of the impregnated powders results in a ZnS-GaP composite structure where the grain sizes of the phases are on the order of 10--20 nm. Conventional powder processing should be able to produce optically dense ceramic compacts with improved mechanical properties and suitable IR transmission.

  18. III. Waiver of Proposed Rulemaking

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

    82 Federal Register / Vol. 77, No. 241 / Friday, December 14, 2012 / Rules and Regulations technical errors in § 447.400(a) and § 447.405 listed on page 66701. One correction ensures consistency between two sentences in the same paragraph and the other restores text inadvertently omitted from the final rule that had been included in the May 11, 2012 notice of proposed rulemaking (77 FR 27671) on pages 26789-90. Thus, we are correcting page 66701 to reflect the correct information. III. Waiver

  19. High Voltage GaN Schottky Rectifiers

    SciTech Connect (OSTI)

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

    1999-10-25

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

  20. Making it pay in Athens, GA

    SciTech Connect (OSTI)

    Malloy, M.G.

    1997-04-01

    The materials recovery facility (MRF) in Athens, GA, is a well-fed recycling facility. But, if the local government has its way, it will be even better fed in the near future. The Athens-Clarke County (ACC) regional municipality in which the facility resides has a put-or-pay contract with the plant`s owner/operator, under which the more it feeds the MRF, the more money it receives in return, through the sale of recycled end products. The ACC Solid Waste Department uses a volume-based waste collection system that encourages residents to recycle--the more they recycle, the less trash they have to put out, and the less they pay each month. The Athens facility, which will be a featured site tour at next month`s WasteExpo `97 in nearby Atlanta, had its ground-breaking two years ago, in April 1995. ACC is responsible for delivering material--or seeing that recyclables are delivered--to the MRF, which is owned and operated by Resource Recovery Systems (RRS, Centerbrook, Conn.). Over the past year, ACC has stepped up various incentives for businesses to recycle and send their recyclables to the facility, including instituting pilot programs for commercial interests that offer them versions of volume-based collection similar to that done by residents.

  1. City of Boulder- Climate Action Plan Fund

    Broader source: Energy.gov [DOE]

    Note: As of 2015, the Climate Action Plan is now referred to as the Climate Commitment. In November 2015, Boulder voters approved an extension of the  Climate Action Plan tax through 2020, with...

  2. Proposal Submission | Linac Coherent Light Source

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

    Proposal Submission Check-In | Computer Accounts | Data Collection & Analysis | Policies | Schedules | Shipping | User Portal The call for new LCLS Proposals for Run 14 closed 4 PM PACIFIC January 11, 2016. Submit new Protein Crystal Screening (PCS) Proposals for Run 14 by 4 PM PACIFIC March 21, 2016. Submit new LCLS Proposals for Run 15 by 4 PM PACIFIC November 7, 2016. LCLS PROPOSALS & PROPOSAL REVIEW PROCESS ( PROPOSAL REVIEW PANEL) Please note the following important information

  3. Outdoor Testing of GaInP2/GaAs Tandem Cells with Top Cell Thickness Varied

    SciTech Connect (OSTI)

    McMahon, W. E.; Emergy, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

    2005-08-01

    In this study, we measure the performance of GaInP2/GaAs tandem cells under direct beam sunlight outdoors in order to quantify their sensitivity to both spectral variation and GaInP2 top-cell thickness. A set of cells with five different top-cell thicknesses was mounted on a two-axis tracker with the incident sunlight collimated to exclude all except the direct beam. Current-voltage (I-V) curves were taken throughout the course of several days, along with measurements of the direct solar spectrum. Our two major conclusions are: (1) GaInP2/GaAs tandem cells designed for either the ASTM G-173 direct (G-173D) spectrum or the "air mass 1.5 global" (AM1.5G) spectrum perform the best, and (2) cells can be characterized indoors and modeled using outdoor spectra with the same result. These results are equally valid for GaInP2/GaAs/Ge triple-junction cells.

  4. SEAB Climate Action Plan | Department of Energy

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

    SEAB Climate Action Plan SEAB Climate Action Plan A presentation on the Climate Action Plan presented by Dr. Jonathan Pershing, Deputy Assistant Secretary for Climate Change at the U.S. Department of Energy. Climate Action Plan (pdf) (998.5 KB) More Documents & Publications U.S. Energy Sector Vulnerabilities to Climate Change and Extreme Weather Climate Change and the U.S. Energy Sector: Regional Vulnerabilities and Resilience Solutions Climate Change: Energy and Community Impacts

  5. EIS-0380: Mitigation Action Plan Annual Report

    Broader source: Energy.gov [DOE]

    Los Alamos National Laboratory Site-Wide Environmental Impact Statement Fiscal Year 2012 Mitigation Action Plan Annual Report

  6. Energy Action Month October 2014 Campaign Materials

    Broader source: Energy.gov [DOE]

    Campaign materials for "Transition to a Clean Energy Reality," the theme for Energy Action Month October 2014.

  7. NREL: Technology Deployment - Climate Action Planning Tool

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

    Home Technology Deployment Climate Action Planning Tool Technology Deployment - Climate Action Planning Tool NREL's Climate Action Planning Tool provides a quick, basic estimate of how various technology options can contribute to an overall climate action plan for your research campus. Use the tool to identify which options will lead to the most significant reductions in consumption of fossil fuels and in turn meet greenhouse gas reduction goals. Follow these four steps: Gather baseline energy

  8. Climate Action Plan | Department of Energy

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

    Climate Action Plan Climate Action Plan Since President Obama's announcement of the Climate Action Plan (CAP) on June 25, 2013, the Department of Energy (DOE) has moved forward to lead initiatives and support interagency efforts that cut carbon pollution, augment resilience and preparedness in the face of climate impacts, and strengthen international partnerships addressing the issue. This effort involves activities all across the Department, including actions led by the Office of International

  9. Energy Action Month | Department of Energy

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

    Energy Action Month Energy Action Month Energy Action Month Lead our nation to a secure, clean, and prosperous energy future As proclaimed by President Obama, October marks Energy Action Month. With the March announcement of Executive Order 13693: Planning for Federal Sustainability in the Next Decade, the federal government faces even more challenging goals to reduce energy consumption. Agencies are committed to stepping up and adopting more sustainable operations to cut greenhouse gas

  10. Action Recommendation for Cyber Resilience

    SciTech Connect (OSTI)

    Choudhury, Sutanay; Rodriguez, Luke R.; Curtis, Darren S.; Oler, Kiri J.; Nordquist, Peter L.; Chen, Pin-Yu; Ray, Indrajit

    2015-09-01

    This paper presents an unifying graph-based model for representing the infrastructure, behavior and missions of an enterprise. We describe how the model can be used to achieve resiliency against a wide class of failures and attacks. We introduce an algorithm for recommending resilience establishing actions based on dynamic updates to the models. Without loss of generality, we show the effectiveness of the algorithm for preserving latency based quality of service (QoS). Our models and the recommendation algorithms are implemented in a software framework that we seek to release as an open source framework for simulating resilient cyber systems.

  11. Local Structures and Interface Morphology of InGaAsN Thin Films Grown on GaAs

    SciTech Connect (OSTI)

    Allerman, A.A.; Chen, J.G.; Geisz, J.F.; Huang, S.; Hulbert, S.L.; Jones, E.D.; Kao, Y.H.; Kurtz, S.; Kurtz, S.R.; Olson, J.M.; Soo, Y.L.

    1999-02-23

    The compound semiconductor system InGaAsN exhibits many intriguing properties which are particularly useful for the development of innovative high efficiency thin film solar cells and long wavelength lasers. The bandgap in these semiconductors can be varied by controlling the content of N and In and the thin films can yet be lattice-matched to GaAs. In the present work, x-ray absorption fine structure (XAFS) and grazing incidence x-ray scattering (GIXS) techniques have been employed to probe the local environment surrounding both N and In atoms as well as the interface morphology of InGaAsN thin films epitaxially grown on GaAs. The soft x-ray XAFS results around nitrogen K-edge reveal that N is in the sp{sup 3} hybridized bonding configuration in InGaAsN and GaAsN, suggesting that N impurities most likely substitute for As sites in these two compounds. The results of In K-edge XAFS suggest a possible trend of a slightly larger coordination number of As nearest neighbors around In atoms in InGaAsN samples with a narrower bandgap whereas the In-As interatomic distance remains practically the same as in InAs within the experimental uncertainties. These results combined suggest that N-substitution of the As sites plays an important role of bandgap-narrowing while in the meantime counteracting the compressive strain caused by In-doping. Grazing incidence x-ray scattering (GIXS) experiments verify that InGaAsN thin films can indeed form very smooth interfaces with GaAs yielding an average interfacial roughness of 5-20{angstrom}.

  12. Electrical spin injection using GaCrN in a GaN based spin light emitting diode

    SciTech Connect (OSTI)

    Banerjee, D.; Ganguly, S.; Saha, D.; Adari, R.; Sankaranarayan, S.; Kumar, A.; Aldhaheri, R. W.; Hussain, M. A.; Balamesh, A. S.

    2013-12-09

    We have demonstrated electrical spin-injection from GaCrN dilute magnetic semiconductor (DMS) in a GaN-based spin light emitting diode (spin-LED). The remanent in-plane magnetization of the thin-film semiconducting ferromagnet has been used for introducing the spin polarized electrons into the non-magnetic InGaN quantum well. The output circular polarization obtained from the spin-LED closely follows the normalized in-plane magnetization curve of the DMS. A saturation circular polarization of ?2.5% is obtained at 200?K.

  13. Microscopic, electrical and optical studies on InGaN/GaN quantum wells based LED devices

    SciTech Connect (OSTI)

    Mutta, Geeta Rani; Venturi, Giulia; Castaldini, Antonio; Cavallini, Anna

    2014-02-21

    We report here on the micro structural, electronic and optical properties of a GaN-based InGaN/GaN MQW LED grown by the MOVPE method. The present study shows that the threading dislocations present in these LED structures are terminated as V pits at the surface and have an impact on the electrical and optical activity of these devices. It has been pointed that these dislocations were of edge, screw and mixed types. EBIC maps suggest that the electrically active defects are screw and mixed dislocations and behave as nonradiative recombinant centres.

  14. Effects of light illumination on electron velocity of AlGaN/GaN heterostructures under high electric field

    SciTech Connect (OSTI)

    Guo, Lei; Yang, Xuelin Cheng, Jianpeng; Sang, Ling; Xu, Fujun; Tang, Ning; Feng, Zhihong; Lv, Yuanjie; Wang, Xinqiang; Shen, B.; Ge, Weikun

    2014-12-15

    We have investigated the variation of electron velocity in AlGaN/GaN heterostructures depending on illuminating light intensity and wavelength. It is shown that the electron velocity at high electric field increases under above-band light illumination. This electron velocity enhancement is found to be related to the photo-generated cold holes which interact with hot electrons and thus accelerate the energy relaxation at high electric field. The results suggest an alternative way to improve the electron energy relaxation rate and hence the electron velocity in GaN based heterostructures.

  15. High-power InGaAs/GaAs quantum-well laser with enhanced broad spectrum of stimulated emission

    SciTech Connect (OSTI)

    Wang, Huolei; Yu, Hongyan; Zhou, Xuliang; Kan, Qiang; Yuan, Lijun; Wang, Wei; Pan, Jiaoqing; Chen, Weixi; Ding, Ying

    2014-10-06

    We report the demonstration of an InGaAs/GaAs quantum well (QW) broadband stimulated emission laser with a structure that integrated a GaAs tunnel junction with two QW active regions. The laser exhibits ultrabroad lasing spectral coverage of ?51?nm at a center wavelength of 1060?nm with a total emission power of 790 mW, corresponding to a high average spectral power density of 15.5 mW/nm, under pulsed current conditions. Compared to traditional lasers, this laser with an asymmetric separate-confinement heterostructure shows broader lasing bandwidth and higher spectral power density.

  16. Final Environmental Assessment of remedial action at the Falls City uranium mill tailings site, Falls City, Texas

    SciTech Connect (OSTI)

    Not Available

    1991-12-01

    This environmental assessment (EA) is prepared pursuant to the National Environmental Policy Act (NEPA), which requires Federal agencies to assess the impacts that their actions may have on the environment. This EA examines the short- and long-term effects of the DOE`s proposed remedial action for the Falls City tailings site. The no action alternative is also examined. The DOE will use the information and analyses presented here to determine whether the proposed action would have a significant impact on the environment. If the impacts are determined to be significant, an EIS will be prepared. If the impacts are not judged to be significant, the DOE will issue an official ``Finding of No Significant Impact`` and implement the proposed action.

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

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

    Liquefied Natural Gas Imports from Qatar (Million Cubic Feet) Elba Island, GA Liquefied Natural Gas Imports from Qatar (Million Cubic Feet) Year Jan Feb Mar Apr May Jun Jul Aug Sep...

  18. Elba Island, GA Natural Gas Liquefied Natural Gas Imports from...

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

    Egypt (Million Cubic Feet) Elba Island, GA Natural Gas Liquefied Natural Gas Imports from Egypt (Million Cubic Feet) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2011 5,780 ...

  19. Linear and nonlinear optical properties of GaAs/Al{sub x}Ga{sub 1?x}As/GaAs/Al{sub y}Ga{sub 1?y}As multi-shell spherical quantum dot

    SciTech Connect (OSTI)

    Emre Kavruk, Ahmet E-mail: aekavruk@gmail.com; Koc, Fatih; Sahin, Mehmet E-mail: mehsahin@gmail.com

    2013-11-14

    In this work, the optical properties of GaAs/Al{sub x}Ga{sub 1?x}As/GaAs/Al{sub y}Ga{sub 1?y}As multi-shell quantum dot heterostructure have been studied as a function of Al doping concentrations for cases with and without a hydrogenic donor atom. It has been observed that the absorption coefficient strength and/or resonant absorption wavelength can be adjusted by changing the Al content of inner-barrier and/or outer-barrier regions. Besides, it has been shown that the donor atom has an important effect on the control of the electronic and optical properties of the structure. The results have been presented as a function of the Al contents of the inner-barrier x and outer-barrier y regions and probable physical reasons have been discussed.

  20. Evaporation-based Ge/.sup.68 Ga Separation

    DOE Patents [OSTI]

    Mirzadeh, Saed; Whipple, Richard E.; Grant, Patrick M.; O'Brien, Jr., Harold A.

    1981-01-01

    Micro concentrations of .sup.68 Ga in secular equilibrium with .sup.68 Ge in strong aqueous HCl solution may readily be separated in ionic form from the .sup.68 Ge for biomedical use by evaporating the solution to dryness and then leaching the .sup.68 Ga from the container walls with dilute aqueous solutions of HCl or NaCl. The chloro-germanide produced during the evaporation may be quantitatively recovered to be used again as a source of .sup.68 Ga. If the solution is distilled to remove any oxidizing agents which may be present as impurities, the separation factor may easily exceed 10.sup.5. The separation is easily completed and the .sup.68 Ga made available in ionic form in 30 minutes or less.

  1. Proposal Submittal and Scheduling Procedures for Macromolecular

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

    Crystallography | Stanford Synchrotron Radiation Lightsource Proposal Submittal and Scheduling Procedures for Macromolecular Crystallography Beam time for macromolecular crystallography projects is obtained by submitting an SSRL Macromolecular Crystallography Proposal. This proposal is peer reviewed by the Structural Molecular Biology and Biophysics subpanel of the SSRL Proposal Review Panel (PRP) for scientific merit and rating and for criticality of synchrotron radiation use. Proposal

  2. DOE Issues Draft Request for Proposals for Hanford Site Occupational

    Office of Environmental Management (EM)

    Certify Air Conditioners and Heat Pumps | Department of Energy Against AeroSys, Inc. for Failure to Certify Air Conditioners and Heat Pumps DOE Institutes Enforcement Action Against AeroSys, Inc. for Failure to Certify Air Conditioners and Heat Pumps February 4, 2010 - 1:58pm Addthis Washington, DC - The Department of Energy's Office of General Counsel has issued a Notice of Proposed Civil Penalty to AeroSys, Inc. for failing to file certification reports or filing data that was not derived

  3. High Quantum Efficiency AlGaN/InGaN Photodetectors

    SciTech Connect (OSTI)

    Buckley, James H; Leopold, Daniel

    2009-11-24

    High efficiency photon counting detectors in use today for high energy particle detection applications have a significant spectral mismatch with typical sources and have a number of practical problems compared with conventional bialkali photomultiplier tubes. Numerous high energy physics experiments that employ scintillation light detectors or Cherenkov detectors would benefit greatly from photomultipliers with higher quantum efficiencies. The need for extending the sensitivity of photon detectors to the blue and UV wavebands comes from the fact that both Cherenkov light and some scintillators have an emission spectrum which is peaked at short wavelengths. This research involves the development of high quantum efficiency, high gain, UV/blue photon counting detectors based on AlGaN/InGaN photocathode heterostructures grown by molecular beam epitaxy (MBE). The work could eventually lead to nearly ideal light detectors with a number of distinct advantages over existing technologies for numerous applications in high-energy physics and particle astrophysics. Potential advantages include much lower noise detection, better stability and radiation resistance than other cathode structures, very low radioactive background levels for deep underground experiments and high detection efficiency of individual UV-visible photons. We are also working on the development of photocathodes with intrinsic gain, initially improving the detection efficiency of hybrid semiconductor-vacuum tube devices, and eventually leading to an all-solid-state photomultiplier device.

  4. Enhanced optical property in quaternary GaInAsSb/AlGaAsSb quantum wells

    SciTech Connect (OSTI)

    Lin, Chien-Hung Lee, Chien-Ping

    2014-10-21

    High quality GaInAsSb/AlGaAsSb quantum wells (QWs) have been grown by molecular beam epitaxy using proper interface treatments. By controlling the group-V elements at interfaces, we obtained excellent optical quality QWs, which were free from undesired localized trap states, which may otherwise severely affect the exciton recombination. Strong and highly efficient exciton emissions up to room temperature with a wavelength of 2.2 μm were observed. A comprehensive investigation on the QW quality was carried out using temperature dependent and power dependent photoluminescence (PL) measurements. The PL emission intensity remains nearly constant at low temperatures and is free from the PL quenching from the defect induced localized states. The temperature dependent emission energy had a bulk-like behavior, indicating high quality well/barrier interfaces. Because of the uniformity of the QWs and smooth interfaces, the low temperature limit of inhomogeneous line width broadening is as small as 5 meV.

  5. 2015 Discovery Science Call for Proposal

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

    users 2015 Discovery Science Call for Proposal Reference Links: - Basic NIF Specs (User ... proposals via the web based form June 30, 2015. Full proposals are due by September 1, ...

  6. Guidance Regarding Actions That May Proceed During the NEPA Process: Interim Actions (DOE, 2003)

    Broader source: Energy.gov [DOE]

    DOE guidance to provide assistance in determining whether an action within the scope of an EIS may be taken before a record of decision is issued. The guidance reviews applicable requirements, gives examples of the types of actions that may proceed as interim actions, describes case studies, and outlines the steps in the EIS process for interim actions.

  7. Guidance Regarding Actions That May Proceed During the NEPA Process: Interim Actions

    Broader source: Energy.gov [DOE]

    DOE guidance to provide assistance in determining whether an action within the scope of an EIS may be taken before a record of decision is issued. The guidance reviews applicable requirements, gives examples of the types of actions that may proceed as interim actions, describes case studies, and outlines the steps in the EIS process for interim actions.

  8. Mismatch relaxation by stacking fault formation of AlN islands in AlGaN/GaN structures on m-plane GaN substrates

    SciTech Connect (OSTI)

    Smalc-Koziorowska, Julita; Sawicka, Marta; Skierbiszewski, Czeslaw; Grzegory, Izabella

    2011-08-08

    We study the mismatch relaxation of 2-5 nm thin elongated AlN islands formed during growth of AlGaN on bulk m-plane GaN by molecular beam epitaxy. The relaxation of these m-plane AlN layers is anisotropic and occurs through the introduction of stacking faults in [0001] planes during island coalescence, while no relaxation is observed along the perpendicular [1120] direction. This anisotropy in the mismatch relaxation and the formation of stacking faults in the AlN islands are explained by the growth mode of the AlN platelets and their coalescence along the [0001] direction.

  9. A new InGaP/GaAs tunneling heterostructure-emitter bipolar transistor (T-HEBT)

    SciTech Connect (OSTI)

    Tsai, Jung-Hui; Lee, Ching-Sung; Lour, Wen-Shiung; Ma, Yung-Chun; Ye, Sheng-Shiun

    2011-05-15

    Excellent characteristics of an InGaP/GaAs tunneling heterostructure-emitter bipolar transistor (T-HEBT) are first demonstrated. The insertion of a thin n-GaAs emitter layer between tynneling confinement and base layers effectivelty eliminates the potential spike at base-emitter junction and reduces the collector-emitter offset voltage, while the thin InGaP tunneling confinement layer is employed to reduce the transporting time across emitter region for electrons and maintain the good confinement effect for holes. Experimentally, the studied T-HEBN exhibits a maximum current gain of 285, a relatively low offset voltage of 40 mW, and a current-gain cutoff frequency of 26.4 GHz.

  10. Characterization of Cu(In,Ga)Se2 (CIGS) films with varying gallium ratios

    SciTech Connect (OSTI)

    Claypoole, Jesse; Peace, Bernadette; Sun, Neville; Dwyer, Dan; Eisaman, Matthew D.; Haldar, Pradeep; Efstathiadis, Harry

    2015-09-05

    Cu(In1-x,Gax)Se2 (CIGS) absorber layers were deposited on molybdenum (Mo) coated soda-lime glass substrates with varying Ga content (described as Ga/(In+Ga) ratios) with respect to depth. As the responsible mechanisms for the limitation of the performance of the CIGS solar cells with high Ga contents are not well understood, the goal of this work was to investigate different properties of CIGS absorber films with Ga/(In+Ga) ratios varied between 0.29 and 0.41 (as determined by X-ray florescence spectroscopy (XRF)) in order to better understand the role that the Ga content has on film quality. The Ga grading in the CIGS layer has the effect causing a higher bandgap toward the surface and Mo contact while the band gap in the middle of the CIGS layer is lower. Also, a wider and larger Ga/(In+Ga) grading dip located deeper in the CIGS absorber layers tend to produce larger grains in the regions of the films that have lower Ga/(In+Ga) ratios. It was found that surface roughness decreases from 51.2 nm to 41.0 nm with increasing Ga/(In+Ga) ratios. However, the surface roughness generally decreases if the Ga grading occurs deeper in the absorber layer.

  11. Quaternary AlInGaN/InGaN quantum well on vicinal c-plane substrate for high emission intensity of green wavelengths

    SciTech Connect (OSTI)

    Park, Seoung-Hwan; Pak, Y. Eugene; Park, Chang Young; Mishra, Dhaneshwar; Yoo, Seung-Hyun; Cho, Yong-Hee Shim, Mun-Bo; Kim, Sungjin

    2015-05-14

    Electronic and optical properties of non-trivial semipolar AlInGaN/InGaN quantum well (QW) structures are investigated by using the multiband effective-mass theory and non-Markovian optical model. On vicinal c-plane GaN substrate miscut by a small angle (??GaN/InGaN system is shown to have ?3 times larger spontaneous emission peak intensity than the conventional InGaN/GaN system at green wavelength. It is attributed to much larger optical matrix element of the quaternary AlInGaN/InGaN system, derived from the reduction of internal electric field induced by polarizations. This effect exceeds the performance-degrading factor of smaller quasi-Fermi-level separation for the quaternary AlInGaN/InGaN system than that for the conventional InGaN/GaN system. Results indicate that the use of quaternary III-nitride QWs on vicinal substrates may be beneficial in improving the performance of optical devices emitting green light.

  12. Proposal Submittal and Scheduling Procedures for Macromolecular...

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

    This proposal is peer reviewed by the Structural Molecular Biology and Biophysics subpanel ... Once a complete proposal is received, it is sent to the Structural Molecular Biology and ...

  13. LOPP Proposal Checklist | Open Energy Information

    Open Energy Info (EERE)

    of specific proposal requirements for lease of power privilege proposals. Author Bureau of Reclamation Published Department of Interior, 2015 DOI Not Provided Check for DOI...

  14. Request for Proposal Guidance | Department of Energy

    Energy Savers [EERE]

    Request for Proposal Guidance Request for Proposal Guidance When purchasing plug-in electric vehicle charging stations as part of your workplace charging program, your organization ...

  15. The first principle study of Ni{sub 2}ScGa and Ni{sub 2}TiGa

    SciTech Connect (OSTI)

    zduran, Mustafa; Turgut, Kemal; Arikan, Nihat; ?yigr, Ahmet; Candan, Abdullah

    2014-10-06

    We computed the electronic structure, elastic moduli, vibrational properties, and Ni{sub 2}TiGa and Ni{sub 2}ScGa alloys in the cubic L2{sub 1} structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C{sub 11}, C{sub 12} and C{sub 44}. We calculated elastic constants in L2{sub 1} structure for Ni{sub 2}TiGa and Ni{sub 2}ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso program package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni{sub 2}TiGa, Ni 3d states and Sc 3d states for Ni{sub 2}ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni{sub 2}TiGa, 0.76 states/eV Cell for Ni{sub 2}ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L2{sub 1} phase is unstable since the phonon calculations have imagine modes.

  16. Climate Action Champions: Portland, OR

    Broader source: Energy.gov [DOE]

    In 1993, Portland became the first local government in the U.S. to adopt a plan for reducing carbon emissions. The current Portland Climate Action Plan was adopted by Portland City Council in 2009. Portland’s overarching climate objective is to reduce emissions to 80 percent below 1990 levels by 2050, with an interim goal of a 40 percent reduction by 2030. Portland has reduced emissions by 14 percent as of 2013, through a combination of improved efficiency in buildings, appliances, and vehicles; a shift to lower-carbon energy sources; a focus on a compact urban development pattern; and a rise in walking, biking and transit made possible by shifts in infrastructure investment.

  17. Fiscal Year 2013 Trails Management Program Mitigation Action Plan Annual Report, October 2013

    SciTech Connect (OSTI)

    Pava, Daniel S.

    2015-03-25

    This Trails Management Program Mitigation Action Plan Annual Report (Trails MAPAR) has been prepared for the Department of Energy (DOE)/National Nuclear Security Administration (NNSA) as part of implementing the 2003 Final Environmental Assessment for the Proposed Los Alamos National Laboratory Trails Management Program (DOE 2003). The Trails Mitigation Action Plan (MAP) is now a part of the Site-Wide Environmental Impact Statement for the Continued Operation of Los Alamos National Laboratory (DOE/EIS 0380) Mitigation Action Plan (2008 SWEIS MAP) (DOE 2008). The MAP provides guidance for the continued implementation of the Trails Management Program at Los Alamos National Laboratory (LANL) and integration of future mitigation actions into the 2008 SWEIS MAP to decrease impacts associated with recreational trails use at LANL. This eighth MAPAR includes a summary of Trails Management Program activities and actions during Fiscal Year (FY) 2013, from October 2012 through September 2013.

  18. Efficient carrier relaxation and fast carrier recombination of N-polar InGaN/GaN light emitting diodes

    SciTech Connect (OSTI)

    Feng, Shih-Wei Liao, Po-Hsun; Leung, Benjamin; Han, Jung; Yang, Fann-Wei; Wang, Hsiang-Chen

    2015-07-28

    Based on quantum efficiency and time-resolved electroluminescence measurements, the effects of carrier localization and quantum-confined Stark effect (QCSE) on carrier transport and recombination dynamics of Ga- and N-polar InGaN/GaN light-emitting diodes (LEDs) are reported. The N-polar LED exhibits shorter ns-scale response, rising, delay, and recombination times than the Ga-polar one does. Stronger carrier localization and the combined effects of suppressed QCSE and electric field and lower potential barrier acting upon the forward bias in an N-polar LED provide the advantages of more efficient carrier relaxation and faster carrier recombination. By optimizing growth conditions to enhance the radiative recombination, the advantages of more efficient carrier relaxation and faster carrier recombination in a competitive performance N-polar LED can be realized for applications of high-speed flash LEDs. The research results provide important information for carrier transport and recombination dynamics of an N-polar InGaN/GaN LED.

  19. Effects of high-temperature AIN buffer on the microstructure of AlGaN/GaN HEMTs

    SciTech Connect (OSTI)

    Coerekci, S.; Oeztuerk, M. K.; Yu, Hongbo; Cakmak, M.; Oezcelik, S.; Oezbay, E.

    2013-06-15

    Effects on AlGaN/GaN high-electron-mobility transistor structure of a high-temperature AlN buffer on sapphire substrate have been studied by high-resolution x-ray diffraction and atomic force microscopy techniques. The buffer improves the microstructural quality of GaN epilayer and reduces approximately one order of magnitude the edge-type threading dislocation density. As expected, the buffer also leads an atomically flat surface with a low root-mean-square of 0.25 nm and a step termination density in the range of 10{sup 8} cm{sup -2}. Due to the high-temperature buffer layer, no change on the strain character of the GaN and AlGaN epitaxial layers has been observed. Both epilayers exhibit compressive strain in parallel to the growth direction and tensile strain in perpendicular to the growth direction. However, an high-temperature AlN buffer layer on sapphire substrate in the HEMT structure reduces the tensile stress in the AlGaN layer.

  20. Optical Performance of Top-Down Fabricated InGaN/GaN Nanorod...

    Office of Scientific and Technical Information (OSTI)

    Resource Type: Journal Article Resource Relation: Journal Name: Optics Express; Related Information: Proposed for publication in Optics Express. Research Org: Sandia National ...

  1. EA-1923: Mitigation Action Plan | Department of Energy

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

    Mitigation Action Plan EA-1923: Mitigation Action Plan Green Energy School Wind Turbine Project on Saipan, Commonwealth of the Northern Mariana Islands This Mitgation Action Plan ...

  2. EIS-0397: Mitigation Action Plan | Department of Energy

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

    Mitigation Action Plan EIS-0397: Mitigation Action Plan Lyle Falls Fish Passage Project This Mitigation Action Plan identifies measures that are intended to avoid, reduce, or...

  3. China-Partnership for Climate Action | Open Energy Information

    Open Energy Info (EERE)

    Partnership for Climate Action (Redirected from Partnership for Climate Action - China) Jump to: navigation, search Name Partnership for Climate Action - China AgencyCompany...

  4. Environmental assessment of remedial action at the Naturita Uranium Processing Site near Naturita, Colorado. Revision 4

    SciTech Connect (OSTI)

    Not Available

    1994-05-01

    The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law (PL) 95-604, authorized the US Department of Energy (DOE) to perform remedial action at the Naturita, Colorado, uranium processing site to reduce the potential health effects from the radioactive materials at the site and at vicinity properties associated with the site. The US Environmental Protection Agency (EPA) promulgated standards for the UMTRCA that contain measures to control the contaminated materials and to protect groundwater quality. Remedial action at the Naturita site must be performed in accordance with these standards and with the concurrence of the US Nuclear Regulatory Commission (NRC) and the state of Colorado. The proposed remedial action for the Naturita processing site is relocation of the contaminated materials and debris to either the Dry Flats disposal site, 6 road miles (mi) [10 kilometers (km)] to the southeast, or a licensed non-DOE disposal facility capable of handling RRM. At either disposal site, the contaminated materials would be stabilized and covered with layers of earth and rock. The proposed Dry Flats disposal site is on land administered by the Bureau of Land Management (BLM) and used primarily for livestock grazing. The final disposal site would cover approximately 57 ac (23 ha), which would be permanently transferred from the BLM to the DOE and restricted from future uses. The remedial action would be conducted by the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. This report discusses environmental impacts associated with the proposed remedial action.

  5. Environmental assessment of remedial action at the Naturita Uranium processing site near Naturita, Colorado. Revision 2

    SciTech Connect (OSTI)

    Not Available

    1994-01-01

    The proposed remedial action for the Naturita processing site is relocation of the contaminated materials and debris to the Dry Flats disposal sits, 6 road miles (mi) [10 kilometers (km)) to the southeast. At the disposal site, the contaminated materials would be stabilized and covered with layers of earth and rock. The proposed disposal site is on land administered by the Bureau of Land Management (BLM) and used primarily for livestock grazing. The final disposal sits would cover approximately 57 ac (23 ha), which would be permanently transferred from the BLM to the DOE and restricted from future uses. The remedial action activities would be conducted by the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The proposed remedial action would result in the loss of approximately 162 ac (66 ha) of soils at the processing and disposal sites; however, 133 ac (55 ha) of these soils at and adjacent to the processing site are contaminated and cannot be used for other purposes. If supplemental standards are approved by the NRC and state of Colorado, approximately 112 ac (45 ha) of contaminated soils adjacent to the processing site would not be cleaned up. This area is steeply sloped. The cleanup of this contamination would have adverse environmental consequences and would be potentially hazardous to remedial action workers. Another 220 ac (89 ha) of soils would be temporarily disturbed during the remedial action. The final disposal site would result in approximately 57 ac (23 ha) being removed from livestock grazing and wildlife use.

  6. Environmental assessment of remedial action at the Naturita uranium processing site near Naturita, Colorado. Revision 3

    SciTech Connect (OSTI)

    Not Available

    1994-02-01

    The proposed remedial action for the Naturita processing site is relocation of the contaminated materials and debris to the Dry Flats disposal site, 6 road miles (mi) [10 kilometers (km)] to the southeast. At the disposal site, the contaminated materials would be stabilized and covered with layers of earth and rock. The proposed disposal site is on land administered by the Bureau of Land Management (BLM) and used primarily for livestock grazing. The final disposal site would cover approximately 57 ac (23 ha), which would be permanently transferred from the BLM to the DOE and restricted from future uses. The remedial action activities would be conducted by the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The proposed remedial action would result in the loss of approximately 162 ac (66 ha) of soils at the processing and disposal sites; however, 133 ac (55 ha) of these soils at and adjacent to the processing site are contaminated and cannot be used for other purposes. If supplemental standards are approved by the NRC and state of Colorado, approximately 112 ac (45 ha) of contaminated soils adjacent to the processing site would not be cleaned up. This area is steeply sloped. The cleanup of this contamination would have adverse environmental consequences and would be potentially hazardous to remedial action workers. Another 220 ac (89 ha) of soils would be temporarily disturbed during the remedial action. The final disposal site would result in approximately 57 ac (23 ha) being removed from livestock grazing and wildlife use.

  7. Corrective Action Decision Document/Closure Report for Corrective Action Unit 309: Area 12 Muckpiles, Nevada Test Site, Nevada, Rev. No.: 0 with Errata Sheet

    SciTech Connect (OSTI)

    Alfred Wickline

    2005-12-01

    This Corrective Action Decision Document/Closure Report (CADD/CR) has been prepared for Corrective Action Unit (CAU) 309, Area 12 Muckpiles, Nevada Test Site (NTS), Nevada. The corrective actions proposed in this document are according to the ''Federal Facility Agreement and Consent Order'' (FFACO) that was agreed to by the State of Nevada, U.S. Department of Energy (DOE), and the U.S. Department of Defense (FFACO, 1996). The NTS is approximately 65 miles (mi) northwest of Las Vegas, Nevada (Figure 1-1). Corrective Action Unit 309 is comprised of the three Corrective Action Sites (CASs) (Figure 1-1) listed below: (1) CAS 12-06-09, Muckpile; (2) CAS 12-08-02, Contaminated Waste Dump (CWD); and (3) CAS 12-28-01, I-, J-, and K-Tunnel Debris. Corrective Action Sites 12-06-09 and 12-08-02 will be collectively referred to as muckpiles in this document. Corrective Action Site 12-28-01 will be referred to as the fallout plume because of the extensive lateral area of debris and fallout contamination resulting from the containment failures of the J- and K-Tunnels. A detailed discussion of the history of this CAU is presented in the ''Corrective Action Investigation Plan (CAIP) for Corrective Action Unit 309: Area 12 Muckpiles, Nevada Test Site (NTS), Nevada.'' (NNSA/NSO, 2004). This CADD/CR provides justification for the closure of CAU 309 without further corrective action. This justification is based on process knowledge and the results of the investigative activities conducted according to the CAIP (NNSA/NSO, 2004), which provides information relating to the history, planning, and scope of the investigation. Therefore, this information will not be repeated in this CADD/CR.

  8. Intermixing of InGaAs/GaAs Quantum Well Using Multiple Cycles Annealing Cu-doped SiO2

    SciTech Connect (OSTI)

    Hongpinyo, V; Ding, Y H; Dimas, C E; Wang, Y; Ooi, B S; Qiu, W; Goddard, L L; Behymer, E M; Cole, G D; Bond, T C

    2008-06-11

    The authors investigate the effect of intermixing in InGaAs/GaAs quantum well structure using Cu-doped SiO{sub 2}. The incorporation of Cu into the silica film yields larger bandgap shift than typical impurity-free vacancy diffusion (IFVD) method at a lower activation temperature. We also observe enhancement of the photoluminescence (PL) signal from the intermixed InGaAs/GaAs quantum well structure after being cycle-annealed at 850 C.

  9. Characterization of Cu(In,Ga)Se2 (CIGS) films with varying gallium ratios

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

    Claypoole, Jesse; Peace, Bernadette; Sun, Neville; Dwyer, Dan; Eisaman, Matthew D.; Haldar, Pradeep; Efstathiadis, Harry

    2015-09-05

    Cu(In1-x,Gax)Se2 (CIGS) absorber layers were deposited on molybdenum (Mo) coated soda-lime glass substrates with varying Ga content (described as Ga/(In+Ga) ratios) with respect to depth. As the responsible mechanisms for the limitation of the performance of the CIGS solar cells with high Ga contents are not well understood, the goal of this work was to investigate different properties of CIGS absorber films with Ga/(In+Ga) ratios varied between 0.29 and 0.41 (as determined by X-ray florescence spectroscopy (XRF)) in order to better understand the role that the Ga content has on film quality. The Ga grading in the CIGS layer hasmore » the effect causing a higher bandgap toward the surface and Mo contact while the band gap in the middle of the CIGS layer is lower. Also, a wider and larger Ga/(In+Ga) grading dip located deeper in the CIGS absorber layers tend to produce larger grains in the regions of the films that have lower Ga/(In+Ga) ratios. It was found that surface roughness decreases from 51.2 nm to 41.0 nm with increasing Ga/(In+Ga) ratios. However, the surface roughness generally decreases if the Ga grading occurs deeper in the absorber layer.« less

  10. Radiation damage of GaAs thin-film solar cells on Si substrates

    SciTech Connect (OSTI)

    Itoh, Y.; Yamaguchi, M.; Nishioka, T.; Yamamoto, A.

    1987-01-15

    1-MeV electron irradiation damages in GaAs thin-film solar cells on Si substrates are examined for the first time. Damage constant for minority-carrier diffusion length in GaAs heteroepitaxial films on Si substrates is found to be the same as that in GaAs homoepitaxial films on GaAs substrates. This agreement suggests that GaAs/Si has the same defect introduction rate with radiation as GaAs/GaAs. The degradation of GaAs solar cells on Si with electron irradiation is less than that of GaAs solar cells on GaAs, because in the present, GaAs films on Si substrates have lower minority-carrier diffusion length compared to GaAs films on GaAs and these films are insensitive to radiation. The p/sup +/-p/sup +/-n AlGaAs-GaAs heteroface solar cell with junction depth of about 0.3 ..mu..m is concluded to be useful for a high-efficiency and radiation-resistant solar cell fabricated on a Si substrate.

  11. Recommendation 191: ETTP contract proposal review

    Broader source: Energy.gov [DOE]

    The ORSSAB offers recommendations Regarding the Request for Proposals for the East Tennessee Technology Park Contract.

  12. Dislocation related droop in InGaN/GaN light emitting diodes investigated via cathodoluminescence

    SciTech Connect (OSTI)

    Pozina, Galia; Ciechonski, Rafal; Bi, Zhaoxia; Samuelson, Lars; Monemar, Bo

    2015-12-21

    Today's energy saving solutions for general illumination rely on efficient white light emitting diodes (LEDs). However, the output efficiency droop experienced in InGaN based LEDs with increasing current injection is a serious limitation factor for future development of bright white LEDs. We show using cathodoluminescence (CL) spatial mapping at different electron beam currents that threading dislocations are active as nonradiative recombination centers only at high injection conditions. At low current, the dislocations are inactive in carrier recombination due to local potentials, but these potentials are screened by carriers at higher injection levels. In CL images, this corresponds to the increase of the dark contrast around dislocations with the injection (excitation) density and can be linked with droop related to the threading dislocations. Our data indicate that reduction of droop in the future efficient white LED can be achieved via a drastic reduction of the dislocation density by using, for example, bulk native substrates.

  13. Radiation resistance of GaAs-GaAlAs vertical cavity surface emitting lasers

    SciTech Connect (OSTI)

    Jabbour, J.; Zazoui, M.; Sun, G.C.; Bourgoin, J.C.; Gilard, O.

    2005-02-15

    The variations of the optical and electrical characteristics of a vertical cavity surface emitting laser based on GaAs quantum wells have been monitored versus irradiation with 1 MeV electrons. The results are understood by the introduction of nonradiative recombination centers in the wells whose characteristics, capture cross section for minority carriers times their introduction rate, can be determined. A similar study performed for proton irradiation shows that the results can be explained in the same way when the introduction rate of the defects is replaced by the proton energy loss into atomic collisions. These results allow us to deduce the equivalence between electron and proton irradiations: A flux of 1 proton cm{sup -2} which loses an energy E{sub nl} (eV) into atomic collisions is equivalent to a fluence of about 9x10{sup -2} E{sub nl} cm{sup -2}, 1 MeV electrons.

  14. Laser Gain and Threshold Properties in Compressive-Strained and Lattice-Matched GaInNAs/GaAs Quantum Wells

    SciTech Connect (OSTI)

    Chow, W.W.; Jones, E.D.; Modine, N.A.; Allerman, A.A.; Kurtz, S.R.

    1999-08-04

    The optical gain spectra for compressive-strained and lattice-matched 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 lasing threshold current density for different GAInNAs/GaAs laser structures.

  15. Structural and optical properties of Ga{sub 2}O{sub 3}:In films deposited on MgO (1 0 0) substrates by MOCVD

    SciTech Connect (OSTI)

    Kong Lingyi; Ma Jin; Luan Caina; Zhu Zhen

    2011-08-15

    Ga{sub 2}O{sub 3}:In films with different indium (In) content x [x=In/(Ga+In) atomic ratio] have been deposited on MgO (1 0 0) substrates by metalorganic chemical vapor deposition (MOCVD). Structural analyses revealed that the film deposited with actual In content (x') of 0.09 was an epitaxial film and the films with x'=0.18 and 0.37 had mixed-phase structures of monoclinic Ga{sub 2}O{sub 3} and bixbyite In{sub 2}O{sub 3}. The absolute average transmittance of the obtained films in the visible region exceeded 95%, and the band gap was in the range of 4.74-4.87 eV. Photoluminescence (PL) measurements were performed at room temperature, in which the visible luminescences were strong and could be seen by the naked eye. The strong emissions in the visible light region were proposed to originate from the gallium vacancies, oxygen deficiencies and other defects in these films. - Graphical abstract: Low magnification XTEM (a), HRTEM (b) and SAED (c) micrographs of the interface area between Ga{sub 1.82}In{sub 0.18}O{sub 3} film and MgO substrate have showed the Ga{sub 1.82}In{sub 0.18}O{sub 3} is an epitaxial film. Highlights: > Ga{sub 1.82}In{sub 0.18}O{sub 3} epitaxial film was deposited on MgO(1 0 0) substrate. > The transmittance of the Ga{sub 2}O{sub 3}:In films in the visible region exceeded 95%. > Strong emissions were observed in the photoluminescence measurements of the films.

  16. Monthly Progress Report for Corrective Actions 2016

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

    Progress Reports for Corrective Actions 2016 Monthly Progress Report for Corrective Actions Prescribed in Attachment A of the Settlement Agreement and Stipulated Final Order, Dated January 22, 2016, NO. HWB-14-21 (CO) Waste Isolation Pilot Plant EPA I.D. Number: NM4890139088-TSDF dated August 31, 2016 Monthly Progress Report for Corrective Actions Prescribed in Attachment A of the Settlement Agreement and Stipulated Final Order, Dated January 22, 2016, NO. HWB-14-21 (CO) Waste Isolation Pilot

  17. Environmental Management Headquarters Corrective Action Plan - Radiological

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

    Release Phase II | Department of Energy II Environmental Management Headquarters Corrective Action Plan - Radiological Release Phase II The purpose of this Corrective Action Plan (CAP) is to specify U.S. Department of Energy (DOE) actions for addressing Office of Environmental Management (EM) Headquarters (HQ) issues identified in the Accident Investigation Report for the Phase 2: Radiological Release Event at the Waste Isolation Pilot Plant (WIPP) on February 14, 2014. The report identified

  18. Key Actions for Optimizing for KNL

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

    Key Actions for Optimizing for KNL Key Actions for Optimizing for KNL This webinar consisted of a presentation by Nathan Wichmann of Cray entitled, "Key Actions When Optimizing for KNL." Nathan is a Principal Performance Engineer responsible for tackling performance problems at Cray for many years and he is our contact for the NERSC/Cray Cori Applications Center of Excellence. Nathan's presentation results, in part, from his participation in several "brainstorming" telecons

  19. Vertical zone melt growth of GaAs

    SciTech Connect (OSTI)

    Henry, R.L.; Nordquist, P.E.R.; Gorman, R.J.

    1993-12-31

    A Vertical Zone Melt (VZM) technique has been applied to the single crystal growth of GaAs. A pyrolytic boron nitride crucible and a (100) oriented seed were used along with liquid encapsulation by boric oxide. In the case of GaAs, the ampoule was pressurized with either argon or argensic vapor from elemental arsenic at pressures ranging from 1 to 2 atmospheres. A molten zone length of 22 mm gave a growth interface which is nearly flat and resulted in routine single crystal growth. Temperature gradients of 4{degrees}C/cm. and 9{degrees}C/cm. have produced dislocation densities of <1000/cm{sup 2} and 2000-5000/cm{sup 2} respectively for 34 mm diameter crystals of GaAs. Post growth cooling rates for GaAs have been 35, 160 and 500{degrees}C/hr. The cooling rate has been found to affect the number and size of arsenic precipitates and the EL2 concentration in the GaAs crystal. The effects of these and other growth parameters on the crystalline perfection and electrical properties of the crystals will be discussed.

  20. Nuclear facility decommissioning and site remedial actions

    SciTech Connect (OSTI)

    Knox, N.P.; Webb, J.R.; Ferguson, S.D.; Goins, L.F.; Owen, P.T.

    1990-09-01

    The 394 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eleventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Programs, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Grand Junction Remedial Action Program, (7) Uranium Mill Tailings Management, (8) Technical Measurements Center, (9) Remedial Action Program, and (10) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and keywords. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects and analyzes information on remedial actions and relevant radioactive waste management technologies.

  1. Worldwide Energy Efficiency Action through Capacity Building...

    Open Energy Info (EERE)

    Capacity Building and Training (WEACT) Jump to: navigation, search Logo: Worldwide Energy Efficiency Action through Capacity Building and Training (WEACT) Name Worldwide...

  2. Mitigation Action Implementation Network (MAIN) | Open Energy...

    Open Energy Info (EERE)

    of Nationally Appropriate Mitigation Actions (NAMAs) and Low-Carbon Development (LCD) strategies in developing countries through regionally based dialogues, web-based...

  3. Climate Protection Action Fund | Open Energy Information

    Open Energy Info (EERE)

    Repower America References The Climate Protetion Action Fund - Contact Us Learn More About Repower America Retrieved from "http:en.openei.orgw...

  4. Solar Action Network | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Solar Action Network Address: PO Box 15546 Place: San Luis Obispo, California Zip: 93401 Phone Number: 5058476527 Website:...

  5. Utilities Working with Industry: Action Plan

    SciTech Connect (OSTI)

    none,

    2010-06-25

    This action plan outlines joint ITP and utility activities that will help reach a national goal of reducing energy by 25 percent over then next 10 years.

  6. Rainforest Action Network RAN | Open Energy Information

    Open Energy Info (EERE)

    pressure corporations into publicly adopting policies that protect rainforests and the human rights of those living in those areas. References: Rainforest Action Network (RAN)1...

  7. A comparison of the RCRA Corrective Action and CERCLA Remedial Action Processes

    SciTech Connect (OSTI)

    Traceski, Thomas T.

    1994-02-01

    This document provides a comprehensive side-by-side comparison of the RCRA corrective action and the CERCLA remedial action processes. On the even-numbered pages a discussion of the RCRA corrective action process is presented and on the odd-numbered pages a comparative discussion of the CERCLA remedial action process can be found. Because the two programs have a difference structure, there is not always a direct correlation between the two throughout the document. This document serves as an informative reference for Departmental and contractor personnel responsible for oversight or implementation of RCRA corrective action and CERCLA remedial action activities at DOE environmental restoration sites.

  8. Rulison Site corrective action report

    SciTech Connect (OSTI)

    1996-09-01

    Project Rulison was a joint US Atomic Energy Commission (AEC) and Austral Oil Company (Austral) experiment, conducted under the AEC`s Plowshare Program, to evaluate the feasibility of using a nuclear device to stimulate natural gas production in low-permeability gas-producing geologic formations. The experiment was conducted on September 10, 1969, and consisted of detonating a 40-kiloton nuclear device at a depth of 2,568 m below ground surface (BGS). This Corrective Action Report describes the cleanup of petroleum hydrocarbon- and heavy-metal-contaminated sediments from an old drilling effluent pond and characterization of the mud pits used during drilling of the R-EX well at the Rulison Site. The Rulison Site is located approximately 65 kilometers (40 miles) northeast of Grand Junction, Colorado. The effluent pond was used for the storage of drilling mud during drilling of the emplacement hole for the 1969 gas stimulation test conducted by the AEC. This report also describes the activities performed to determine whether contamination is present in mud pits used during the drilling of well R-EX, the gas production well drilled at the site to evaluate the effectiveness of the detonation in stimulating gas production. The investigation activities described in this report were conducted during the autumn of 1995, concurrent with the cleanup of the drilling effluent pond. This report describes the activities performed during the soil investigation and provides the analytical results for the samples collected during that investigation.

  9. 230 s room-temperature storage time and 1.14 eV hole localization energy in In{sub 0.5}Ga{sub 0.5}As quantum dots on a GaAs interlayer in GaP with an AlP barrier

    SciTech Connect (OSTI)

    Bonato, Leo Sala, Elisa M.; Stracke, Gernot; Nowozin, Tobias; Strittmatter, André; Ajour, Mohammed Nasser; Daqrouq, Khaled; Bimberg, Dieter

    2015-01-26

    A GaP n{sup +}p-diode containing In{sub 0.5}Ga{sub 0.5}As quantum dots (QDs) and an AlP barrier is characterized electrically, together with two reference samples: a simple n{sup +}p-diode and an n{sup +}p-diode with AlP barrier. Localization energy, capture cross-section, and storage time for holes in the QDs are determined using deep-level transient spectroscopy. The localization energy is 1.14(±0.04) eV, yielding a storage time at room temperature of 230(±60) s, which marks an improvement of 2 orders of magnitude compared to the former record value in QDs. Alternative material systems are proposed for still higher localization energies and longer storage times.

  10. NE-24 Unlverslty of Chicayo Remedial Action Plan

    Office of Legacy Management (LM)

    (YJ 4 tlsj .?I2 416 17 1983 NE-24 Unlverslty of Chicayo Remedial Action Plan 22&d 7 IA +-- E. I.. Keller, Director Technical Services Division Oak Ridge Operations Ufflce In response to your memorandum dated July 29, 1983, the Field Task Proposal/Agreement (FTP/A) received frw Aryonne National Laboratory (ANL) appears to be satisfactory, and this office concurs in the use of ANL to provide the decontamination effort as noted in the FTP/A. The final decontaminatton report should Include the

  11. Increased bismuth concentration in MBE GaAs{sub 1−x}Bi{sub x} films by oscillating III/V flux ratio during growth

    SciTech Connect (OSTI)

    Wood, Adam W. Babcock, Susan E.; Li, Jincheng; Brown, April S.

    2015-05-15

    The authors have examined bismuth concentration profiles in GaAs{sub 1−x}Bi{sub x} films grown by molecular beam epitaxy using high angle annular dark field imaging (Z-contrast imaging) in an aberration-corrected scanning transmission electron microscope in conjunction with x-ray diffraction. Samples were grown with a gradient in each of the component fluxes, and therefore, the III/V ratio across the substrate. Rotating the sample during growth exposed the growth surface to an oscillating III/V flux ratio. Sinusoidal [Bi] profiles resulted in the growth direction, the wavelength and number of which were consistent with the growth rate and the rate of substrate rotation. However, the magnitude of [Bi] in the observed fluctuations was greater than the maximum [Bi] achieved using the same Bi flux and Ga/As flux ratios in steady-state conditions on a stationary substrate, suggesting that varying the III/V flux ratio during growth promotes the incorporation of Bi in GaAs{sub 1−x}Bi{sub x} films. A proposed qualitative model for how this enhancement might occur hypothesizes a critical role for alternating growth and shrinkage of Ga-Bi predroplet clusters on the surface as the growing material is rotated through Ga-rich and As-rich flux compositions.

  12. Portsmouth Proposed Plan for the Process Buildings and Complex Facilities Decontamination and Decommissioning Evaluation Project

    Broader source: Energy.gov [DOE]

    DOE has evaluated alternatives for demolishing the buildings at the Portsmouth Site. Two remedial alternatives were developed for consideration. This Proposed Plan describes the required no-action alternative (Alternative 1) and a D&D alternative (Alternative 2). The preferred alternative is Alternative 2, controlled demolition of the process buildings and complex facilities.

  13. EA-1993: Proposed High Explosive Science & Engineering Project, Pantex Plant, Amarillo, Texas

    Broader source: Energy.gov [DOE]

    The proposed action would be to design, construct, and operate a High Explosive Science and Engineering (HE S&E) facility that would support NNSA’s mission at the Pantex Plant. The HE S&E facility would serve as the scientific and engineering hub supporting all High Explosive Center of Excellence activities and technology development activities at Pantex.

  14. Quaternary InGaAsSb Thermophotovoltaic Diode Technology

    SciTech Connect (OSTI)

    M Dashiell; J Beausang; H Ehsani; G Nichols; D DePoy; L Danielson; P Talamo; K Rahner; E Brown; S Burger; P Fourspring; W Topper; P Baldasaro; C Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; Jizhong Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryl

    2005-01-26

    Thermophotovoltaic (TPV) diodes fabricated from InGaAsSb alloys lattice-matched to GaSb substrates are grown by Metal Organic Vapor Phase Epitaxy (MOVPE). 0.53eV InGaAsSb TPV diodes utilizing front-surface spectral control filters have been tested in a vacuum cavity and a TPV thermal-to-electric conversion efficiency ({eta}{sub TPV}) and a power density (PD) of {eta}{sub TPV} = 19% and PD=0.58 W/cm{sup 2} were measured for T{sub radiator} = 950 C and T{sub diode} = 27 C. Recombination coefficients deduced from minority carrier measurements and the theory reviewed in this article predict a practical limit to the maximum achievable conversion efficiency and power density for 0.53eV InGaAsSb TPV. The limits for the above operating temperatures are projected to be {eta}{sub TPV} = 26% and PD = 0.75 W/cm{sup 2}. These limits are extended to {eta}{sub TPV} = 30% and PD = 0.85W/cm{sup 2} if the diode active region is bounded by a reflective back surface to enable photon recycling and a two-pass optical path length. The internal quantum efficiency of the InGaAsSb TPV diode is close to the theoretically predicted limits, with the exception of short wavelength absorption in GaSb contact layers. Experiments show that the open circuit voltage of the 0.53eV InGaAsSb TPV diodes is not strongly dependent on the device architectures studied in this work where both N/P and P/N double heterostructure diodes have been grown with various acceptor and donor doping levels, having GaSb and AlGaAsSb confinement, and also partial back surface reflectors. Lattice matched InGaAsSb TPV diodes were fabricated with bandgaps ranging from 0.6 to 0.5eV without significant degradation of the open circuit voltage factor, quantum efficiency, or fill factor as the composition approached the miscibility gap. The key diode performance parameter which is limiting efficiency and power density below the theoretical limits in InGaAsSb TPV devices is the open circuit voltage. The open circuit voltages of

  15. Structural transformations in amorphous ↔ crystalline phase change of Ga-Sb alloys

    SciTech Connect (OSTI)

    Edwards, T. G.; Sen, S.; Hung, I.; Gan, Z.; Kalkan, B.; Raoux, S.

    2013-12-21

    Ga-Sb alloys with compositions ranging between ∼12 and 50 at. % Ga are promising materials for phase change random access memory applications. The short-range structures of two such alloys with compositions Ga{sub 14}Sb{sub 86} and Ga{sub 46}Sb{sub 54} are investigated, in their amorphous and crystalline states, using {sup 71}Ga and {sup 121}Sb nuclear magnetic resonance spectroscopy and synchrotron x-ray diffraction. The Ga and Sb atoms are fourfold coordinated in the as-deposited amorphous Ga{sub 46}Sb{sub 54} with nearly 40% of the constituent atoms being involved in Ga-Ga and Sb-Sb homopolar bonding. This necessitates extensive bond switching and elimination of homopolar bonds during crystallization. On the other hand, Ga and Sb atoms are all threefold coordinated in the as-deposited amorphous Ga{sub 14}Sb{sub 86}. Crystallization of this material involves phase separation of GaSb domains in Sb matrix and a concomitant increase in the Ga coordination number from 3 to 4. Results from crystallization kinetics experiments suggest that the melt-quenching results in the elimination of structural “defects” such as the homopolar bonds and threefold coordinated Ga atoms in the amorphous phases of these alloys, thereby rendering them structurally more similar to the corresponding crystalline states compared to the as-deposited amorphous phases.

  16. Nano-scale luminescence characterization of individual InGaN/GaN quantum wells stacked in a microcavity using scanning transmission electron microscope cathodoluminescence

    SciTech Connect (OSTI)

    Schmidt, Gordon Mller, Marcus; Veit, Peter; Bertram, Frank; Christen, Jrgen; Glauser, Marlene; Carlin, Jean-Franois; Cosendey, Gatien; Butt, Raphal; Grandjean, Nicolas

    2014-07-21

    Using cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope at liquid helium temperatures, the optical and structural properties of a 62 InGaN/GaN multiple quantum well embedded in an AlInN/GaN based microcavity are investigated at the nanometer scale. We are able to spatially resolve a spectral redshift between the individual quantum wells towards the surface. Cathodoluminescence spectral linescans allow directly visualizing the critical layer thickness in the quantum well stack resulting in the onset of plastic relaxation of the strained InGaN/GaN system.

  17. Call for General User Proposals - Upcoming Deadline

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

    Call for General User Proposals - Upcoming Deadline Call for General User Proposals - Upcoming Deadline Print The User Office is accepting new General User Proposals (GUPs) from scientists who wish to conduct research at the ALS in the 2016-2 July-Dec cycle. PROPOSAL SUBMISSION DEADLINE: March 2, 2016 Please log in to ALSHub to submit a new GUP or to make a Beam Time Request (BTR) on an existing active proposal. Users are reminded that they need to have an ALSHub account to submit proposals, and

  18. Highly transparent ammonothermal bulk GaN substrates

    SciTech Connect (OSTI)

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

    2014-10-01

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

  19. Graphene/GaN diodes for ultraviolet and visible photodetectors

    SciTech Connect (OSTI)

    Lin, Fang; Chen, Shao-Wen; Meng, Jie; Tse, Geoffrey; Fu, Xue-Wen; Xu, Fu-Jun [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Shen, Bo; Liao, Zhi-Min, E-mail: liaozm@pku.edu.cn, E-mail: yudp@pku.edu.cn; Yu, Da-Peng, E-mail: liaozm@pku.edu.cn, E-mail: yudp@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-08-18

    The Schottky diodes based on graphene/GaN interface are fabricated and demonstrated for the dual-wavelength photodetection of ultraviolet (UV) and green lights. The physical mechanisms of the photoelectric response of the diodes with different light wavelengths are different. For UV illumination, the photo-generated carriers lower the Schottky barrier and increase the photocurrent. For green light illumination, as the photon energy is smaller than the bandgap of GaN, the hot electrons excited in graphene via internal photoemission are responsible for the photoelectric response. Using graphene as a transparent electrode, the diodes show a ?mS photoresponse, providing an alternative route toward multi-wavelength photodetectors.

  20. Simple intrinsic defects in GaAs : numerical supplement.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2012-04-01

    This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

  1. Polycrystalline MBE-grown GaAs for solar cells

    SciTech Connect (OSTI)

    Friedman, D.J.; Kurtz, S.R.; Kibbler, A.E.; Al-Jassim, M.; Jones, K.; Keyes, B.; Matson, R.

    1997-02-01

    This paper will discuss initial studies of thin-film GaAs grown by molecular-beam epitaxy for use in developing a thin-film GaAs solar cell. Photocurrent and photoluminescence intensity are related to the material morphology as a function of growth conditions. Growth temperature and V/III ratio have a dramatic effect on the photocurrent. However, it seems likely that even after optimizing such growth parameters, it will be necessary to provide substrates that can provide templates to enhance grain size from the start of thin-film growth. {copyright} {ital 1997 American Institute of Physics.}

  2. Polycrystalline MBE-grown GaAs for solar cells

    SciTech Connect (OSTI)

    Friedman, D. J.; Kurtz, Sarah R.; Kibbler, A. E.; Al-Jassim, M.; Jones, K.; Keyes, B.; Matson, R.

    1997-02-15

    This paper will discuss initial studies of thin-film GaAs grown by molecular-beam epitaxy for use in developing a thin-film GaAs solar cell. Photocurrent and photoluminescence intensity are related to the material morphology as a function of growth conditions. Growth temperature and V/III ratio have a dramatic effect on the photocurrent. However, it seems likely that even after optimizing such growth parameters, it will be necessary to provide substrates that can provide templates to enhance grain size from the start of thin-film growth.

  3. Corrective Action Plan for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada

    SciTech Connect (OSTI)

    K. B. Campbell

    2002-06-01

    This Corrective Action Plan (CAP) provides selected corrective action alternatives and proposes the closure methodology for Corrective Action Unit (CAU) 262, Area 25 Septic Systems and Underground Discharge Point. CAU 262 is identified in the Federal Facility Agreement and Consent Order (FFACO) of 1996. Remediation of CAU 262 is required under the FFACO. CAU 262 is located in Area 25 of the Nevada Test Site (NTS), approximately 100 kilometers (km) (62 miles [mi]) northwest of Las Vegas, Nevada. The nine Corrective Action Sites (CASs) within CAU 262 are located in the Nuclear Rocket Development Station complex. Individual CASs are located in the vicinity of the Reactor Maintenance, Assembly, and Disassembly (R-MAD); Engine Maintenance, Assembly, and Disassembly (E-MAD); and Test Cell C compounds. CAU 262 includes the following CASs as provided in the FFACO (1996); CAS 25-02-06, Underground Storage Tank; CAS 25-04-06, Septic Systems A and B; CAS 25-04-07, Septic System; CAS 25-05-03, Leachfield; CAS 25-05-05, Leachfield; CAS 25-05-06, Leachfield; CAS 25-05-08, Radioactive Leachfield; CAS 25-05-12, Leachfield; and CAS 25-51-01, Dry Well. Figures 2, 3, and 4 show the locations of the R-MAD, the E-MAD, and the Test Cell C CASs, respectively. The facilities within CAU 262 supported nuclear rocket reactor engine testing. Activities associated with the program were performed between 1958 and 1973. However, several other projects used the facilities after 1973. A significant quantity of radioactive and sanitary waste was produced during routine operations. Most of the radioactive waste was managed by disposal in the posted leachfields. Sanitary wastes were disposed in sanitary leachfields. Septic tanks, present at sanitary leachfields (i.e., CAS 25-02-06,2504-06 [Septic Systems A and B], 25-04-07, 25-05-05,25-05-12) allowed solids to settle out of suspension prior to entering the leachfield. Posted leachfields do not contain septic tanks. All CASs located in CAU 262 are

  4. Enhanced sheet carrier densities in polarization controlled AlInN/AlN/GaN/InGaN field-effect transistor on Si (111)

    SciTech Connect (OSTI)

    Hennig, J. Dadgar, A.; Witte, H.; Bläsing, J.; Lesnik, A.; Strittmatter, A.; Krost, A.

    2015-07-15

    We report on GaN based field-effect transistor (FET) structures exhibiting sheet carrier densities of n = 2.9 10{sup 13} cm{sup −2} for high-power transistor applications. By grading the indium-content of InGaN layers grown prior to a conventional GaN/AlN/AlInN FET structure control of the channel width at the GaN/AlN interface is obtained. The composition of the InGaN layer was graded from nominally x{sub In} = 30 % to pure GaN just below the AlN/AlInN interface. Simulations reveal the impact of the additional InGaN layer on the potential well width which controls the sheet carrier density within the channel region of the devices. Benchmarking the In{sub x}Ga{sub 1−x}N/GaN/AlN/Al{sub 0.87}In{sub 0.13}N based FETs against GaN/AlN/AlInN FET reference structures we found increased maximum current densities of I{sub SD} = 1300 mA/mm (560 mA/mm). In addition, the InGaN layer helps to achieve broader transconductance profiles as well as reduced leakage currents.

  5. Strain relaxation in GaN/Al{sub x}Ga{sub 1-x}N superlattices grown by plasma-assisted molecular-beam epitaxy

    SciTech Connect (OSTI)

    Kotsar, Y.; Bellet-Amalric, E.; Das, A.; Monroy, E.; Sarigiannidou, E.

    2011-08-01

    We have investigated the misfit relaxation process in GaN/Al{sub x}Ga{sub 1-x}N (x = 0.1, 0.3, 0.44) superlattices (SL) deposited by plasma-assisted molecular beam epitaxy. The SLs under consideration were designed to achieve intersubband absorption in the mid-infrared spectral range. We have considered the case of growth on GaN (tensile stress) and on AlGaN (compressive stress) buffer layers, both deposited on GaN-on-sapphire templates. Using GaN buffer layers, the SL remains almost pseudomorphic for x = 0.1, 0.3, with edge-type threading dislocation densities below 9 x 10{sup 8} cm{sup -2} to 2 x 10{sup 9} cm{sup -2}. Increasing the Al mole fraction to 0.44, we observe an enhancement of misfit relaxation resulting in dislocation densities above 10{sup 10} cm{sup -2}. In the case of growth on AlGaN, strain relaxation is systematically stronger, with the corresponding increase in the dislocation density. In addition to the average relaxation trend of the SL, in situ measurements indicate a periodic fluctuation of the in-plane lattice parameter, which is explained by the different elastic response of the GaN and AlGaN surfaces to the Ga excess at the growth front. The results are compared with GaN/AlN SLs designed for near-infrared intersubband absorption.

  6. Alloy inhomogeneity and carrier localization in AlGaN sections and AlGaN/AlN nanodisks in nanowires with 240350?nm emission

    SciTech Connect (OSTI)

    Himwas, C.; Hertog, M. den; Dang, Le Si; Songmuang, R.; Monroy, E.

    2014-12-15

    We present structural and optical studies of AlGaN sections and AlGaN/AlN nanodisks (NDs) in nanowires grown by plasma-assisted molecular beam epitaxy. The Al-Ga intermixing at Al(Ga)N/GaN interfaces and the chemical inhomogeneity in AlGaN NDs evidenced by scanning transmission electron microscopy are attributed to the strain relaxation process. This interpretation is supported by the three-dimensional strain distribution calculated by minimizing the elastic energy in the structure. The alloy inhomogeneity increases with the Al content, leading to enhanced carrier localization signatures in the luminescence characteristics, i.e., red shift of the emission, s-shaped temperature dependence, and linewidth broadening. Despite these effects, the emission energy of AlGaN/AlN NDs can be tuned in the 240350?nm range with internal quantum efficiencies around 30%.

  7. Characteristics of InGaP/InGaAs pseudomorphic high electron mobility transistors with triple delta-doped sheets

    SciTech Connect (OSTI)

    Chu, Kuei-Yi; Chiang, Meng-Hsueh Cheng, Shiou-Ying; Liu, Wen-Chau

    2012-02-15

    Fundamental and insightful characteristics of InGaP/InGaAs double channel pseudomorphic high electron mobility transistors (DCPHEMTs) with graded and uniform triple {delta}-doped sheets are coomprehensively studied and demonstrated. To gain physical insight, band diagrams, carrier densities, and direct current characteristics of devices are compared and investigated based on the 2D semiconductor simulator, Atlas. Due to uniform carrier distribution and high electron density in the double InGaAs channel, the DCPHEMT with graded triple {delta}-doped sheets exhibits better transport properties, higher and linear transconductance, and better drain current capability as compared with the uniformly triple {delta}-doped counterpart. The DCPHEMT with graded triple {delta}-doped structure is fabricated and tested, and the experimental data are found to be in good agreement with simulated results.

  8. High-performance broadband optical coatings on InGaN/GaN solar cells for multijunction device integration

    SciTech Connect (OSTI)

    Young, N. G. Farrell, R. M.; Iza, M.; Speck, J. S.; Perl, E. E.; Keller, S.; Bowers, J. E.; Nakamura, S.; DenBaars, S. P.

    2014-04-21

    We demonstrate InGaN/GaN multiple quantum well solar cells grown by metalorganic chemical vapor deposition on a bulk (0001) substrate with high-performance broadband optical coatings to improve light absorption. A front-side anti-reflective coating and a back-side dichroic mirror were designed to minimize front surface reflections across a broad spectral range and maximize rear surface reflections only in the spectral range absorbed by the InGaN, making the cells suitable for multijunction solar cell integration. Application of optical coatings increased the peak external quantum efficiency by 56% (relative) and conversion efficiency by 37.5% (relative) under 1 sun AM0 equivalent illumination.

  9. Fabrication and Characterization of a Single Hole Transistor in p-type GaAs/AlGaAs Heterostructures

    SciTech Connect (OSTI)

    Tracy, Lisa A; Reno, John L.; Hargett, Terry W.

    2015-09-01

    Most spin qubit research to date has focused on manipulating single electron spins in quantum dots. However, hole spins are predicted to have some advantages over electron spins, such as reduced coupling to host semiconductor nuclear spins and the ability to control hole spins electrically using the large spin-orbit interaction. Building on recent advances in fabricating high-mobility 2D hole systems in GaAs/AlGaAs heterostructures at Sandia, we fabricate and characterize single hole transistors in GaAs. We demonstrate p-type double quantum dot devices with few-hole occupation, which could be used to study the physics of individual hole spins and control over coupling between hole spins, looking towards eventual applications in quantum computing. Intentionally left blank

  10. Terahertz intersubband absorption in non-polar m-plane AlGaN/GaN quantum wells

    SciTech Connect (OSTI)

    Edmunds, C.; Malis, O.; Shao, J.; Shirazi-HD, M.; Manfra, M. J.

    2014-07-14

    We demonstrate THz intersubband absorption (15.6–26.1 meV) in m-plane AlGaN/GaN quantum wells. We find a trend of decreasing peak energy with increasing quantum well width, in agreement with theoretical expectations. However, a blue-shift of the transition energy of up to 14 meV was observed relative to the calculated values. This blue-shift is shown to decrease with decreasing charge density and is, therefore, attributed to many-body effects. Furthermore, a ∼40% reduction in the linewidth (from roughly 8 to 5 meV) was obtained by reducing the total sheet density and inserting undoped AlGaN layers that separate the wavefunctions from the ionized impurities in the barriers.

  11. Inversion-mode GaAs wave-shaped field-effect transistor on GaAs (100) substrate

    SciTech Connect (OSTI)

    Zhang, Jingyun; Si, Mengwei; Wu, Heng; Ye, Peide D.; Lou, Xiabing; Gordon, Roy G.; Shao, Jiayi; Manfra, Michael J.

    2015-02-16

    Inversion-mode GaAs wave-shaped metal-oxide-semiconductor field-effect transistors (WaveFETs) are demonstrated using atomic-layer epitaxy of La{sub 2}O{sub 3} as gate dielectric on (111)A nano-facets formed on a GaAs (100) substrate. The wave-shaped nano-facets, which are desirable for the device on-state and off-state performance, are realized by lithographic patterning and anisotropic wet etching with optimized geometry. A well-behaved 1 μm gate length GaAs WaveFET shows a maximum drain current of 64 mA/mm, a subthreshold swing of 135 mV/dec, and an I{sub ON}/I{sub OFF} ratio of greater than 10{sup 7}.

  12. Degradation of InGaN/GaN laser diodes investigated by micro-cathodoluminescence and micro-photoluminescence

    SciTech Connect (OSTI)

    Meneghini, M. Carraro, S.; Meneghesso, G.; Trivellin, N.; Zanoni, E.; Rossi, F.; Salviati, G.; Schade, L.; Karunakaran, M. A.; Schwarz, U. T.

    2013-12-02

    We present an investigation of the degradation of InGaN/GaN laser diodes grown on a GaN substrate. The results indicate that: (i) Ageing induces a significant increase in the threshold current (Ith) of the lasers, which is attributed to an increase in non-radiative recombination; (ii) Ith increase is correlated to a decrease in the micro-cathodoluminescence signal measured (after the removal of the top metallization) in the region under the ridge; (iii) micro-photoluminescence measurements indicate that constant current stress increases non-radiative recombination within the quantum wells (and not only within the barriers), and induces an increase in the emission wavelength of the degraded region.

  13. Strong enhancement of terahertz emission from GaAs in InAs/GaAs quantum dot structures

    SciTech Connect (OSTI)

    Estacio, Elmer; Pham, Minh Hong; Takatori, Satoru; Cadatal-Raduban, Marilou; Nakazato, Tomoharu; Shimizu, Toshihiko; Sarukura, Nobuhiko; Somintac, Armando; Defensor, Michael; Awitan, Fritz Christian B.; Jaculbia, Rafael B.; Salvador, Arnel; Garcia, Alipio

    2009-06-08

    We report on the intense terahertz emission from InAs/GaAs quantum dot (QD) structures grown by molecular beam epitaxy. Results reveal that the QD sample emission was as high as 70% of that of a p-type InAs wafer, the most intense semiconductor emitter to date. Excitation wavelength studies showed that the emission was due to absorption in strained undoped GaAs, and corresponds to a two order-of-magnitude enhancement. Moreover, it was found that multilayer QDs emit more strongly compared with a single layer QD sample. At present, we ascribe the intense radiation to huge strain fields at the InAs/GaAs interface.

  14. Corrective Action Plan for Corrective Action Unit 424: Area 3 Landfill Complex, Tonopah Test Range, Nevada

    SciTech Connect (OSTI)

    Bechtel Nevada

    1998-08-31

    This corrective action plan provides the closure implementation methods for the Area 3 Landfill Complex, Corrective Action Unit (CAU) 424, located at the Tonopah Test Range. The Area 3 Landfill Complex consists of 8 landfill sites, each designated as a separate corrective action site.

  15. Evaluation and Selection of CSES Proposals

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

    Evaluating, Selecting Proposals Evaluation and Selection of CSES Proposals High quality, cutting-edge science in the areas of astrophysics, space physics, solid planetary geoscience, and climate science. Contact Director Reiner Friedel (505) 665-1936 Email Professional Staff Assistant Georgia D. Sanchez (505) 665-0855 Email Geophysics W. Scott Baldridge (505) 667-4338 Email New student and postdoc proposals All new proposals undergo peer review by scientists in the broad research community who

  16. Microsoft Word - AAFS_Proposal_VB.doc

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

    PROPOSAL FACT SHEET PAC cycle: (Do not complete) Date: Assigned Experiment Number Title: Experiment Spokesperson and Alternate: Telephone and...

  17. Proposal Process in Brief | Argonne National Laboratory

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

    Process in Brief The international scientific community can perform research at the CNM through a general user access program. Proposals are submitted through a online proposal system. Proposals are peer-reviewed, rated, and time is allocated on the basis of these reviews by appropriate allocation committees. How to Submit a Proposal You must register online through the User Facility Registration System. Study the CNM Research Groups and identify the capabilities you plan to use. Consult the

  18. Proposal Writing Guidelines and Scoring Criteria

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

    Proposal Writing Guidelines and Scoring Criteria Print Principal Investigator The proposal form asks for the names and contact information of the experiment leader completing the form and the Principal Investigator (PI). The PI is the leader and the individual responsible for the group, and the experiment leader is often the person completing the proposal form. In this way the ALS would like to encourage postdocs and students to gain experience in submitting proposals as the experiment leader,

  19. Return on investment (ROI) proposal preparation guide

    SciTech Connect (OSTI)

    VALERO, O.J.

    1998-10-09

    The ROI Proposal Preparation Guide is a tool to assist Hanford waste generators in preparing ROI proposal forms for submittal to Department of Energy, Richland Operations Office (DOE/RL) for funding. The guide describes the requirements for submitting an ROI proposal and provides examples of completed ROI forms. The intent is to assist waste generators in identifying projects that meet the criteria, provide information necessary to complete the ROI forms, and submit a proposal that is eligible to receive funding.

  20. 2013 INCITE Proposals due June 27

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

    INCITE Proposals 2013 INCITE Proposals due June 27 June 15, 2012 by Francesca Verdier The Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program promotes transformational advances in science and technology through large allocations of computer time, supporting resources, and data storage at the Argonne and Oak Ridge Leadership Computing Facilities. 2013 proposals are due June 27. See 2013 INCITE Call for Proposals. Subscribe via RSS Subscribe Browse by Date August