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Sample records for junction greenfield grundy

  1. Greenfield Wind | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name Greenfield Wind Facility Greenfield Wind Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Greenfield Wind Power...

  2. Grundy Center Mun Light & Power | Open Energy Information

    Open Energy Info (EERE)

    www.gcmuni.nettextcontactus. Facebook: https:www.facebook.compagesCity-of-Grundy-Center169381736410558 Outage Hotline: (319)-825-5207 References: EIA Form EIA-861 Final...

  3. City of Greenfield, Iowa (Utility Company) | Open Energy Information

    Open Energy Info (EERE)

    of Greenfield Place: Iowa Phone Number: (641) 743-2741 or (641) 743-2914 Website: gmu-ia.com Facebook: https:www.facebook.comGreenfieldMunicipalUtilities Outage Hotline:...

  4. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    SciTech Connect (OSTI)

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  5. Best Practices Case Study: Rural Development, Inc., Wisdom Way Solar Village, Greenfield, MA

    SciTech Connect (OSTI)

    2010-12-01

    Wisdom Way Solar Village is an appropriate moniker for the 20-unit community of energy-efficient duplexes in Greenfield, MA. The homes meet the requirements of the U.S. Department of Energys Builders Challenge, achieving HERS scores of 8 to 18 by packing energy efficiency features into the compact, heavily insulated homes and adding solar water heating and photovoltaics on top, to net home owners energy cost savings of at least $2,500 per year per home.

  6. Nanotube junctions

    DOE Patents [OSTI]

    Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon Sheng; Zettl, Alexander Karlwalter

    2003-01-01

    The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

  7. Nanotube junctions

    DOE Patents [OSTI]

    Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon; Zettl, Alexander Karlwalte

    2004-12-28

    The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

  8. Josephson junction

    DOE Patents [OSTI]

    Wendt, J.R.; Plut, T.A.; Martens, J.S.

    1995-05-02

    A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material. 10 figs.

  9. Josephson junction

    DOE Patents [OSTI]

    Wendt, Joel R.; Plut, Thomas A.; Martens, Jon S.

    1995-01-01

    A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material.

  10. PRB coal safety design considerations for new greenfield plants: an EPCC's perspective

    SciTech Connect (OSTI)

    Brown, J.H.

    2007-11-15

    The article reviews the design and safety aspects to consider in a new greenfield Powder River Basin (PRB) coal-fired power plant such as the 200 MW TS Power Plant (TSPP) in Nevada that Fluor is working on as an engineering, procurement and construction contractor (EPCC). PRB coals can become fragmented and form coal dust that is highly volatile and easily self-ignited. Coal handling systems incorporate features to minimise dust, such as totally enclosed chute works, 'spoon drops' to reduce impact turbulence, and overflow hoods. Conveyors have extended skirtboards and tight clearances between the wear plates and the belts. Storage piles are designed to have high compaction to deprive oxygen and dust suppression monitor hydrants to minimise dust and assist in compaction. The coal silo filling bay is designed to minimise dust once the coal is crushed, and attention is paid to cleaning and lighting. The silos are designed to ensure mass flow to the feeder and incorporate a carbon monoxide monitor and an F-500 fire suppressant. 3 photos.

  11. The Carver-Greenfield Process: dehydration/solvent extraction technology for waste treatment

    SciTech Connect (OSTI)

    Trowbridge, T.D.; Holcombe, T.C.

    1996-12-31

    A combination dehydration/solvent extraction treatment technology, the proprietary Carver-Greenfield (C-G) Process, can be used to separate solid/liquid waste materials into three separate product streams convenient for reuse or disposal: (1) clean, dry solids suitable for fixation of nonhazardous landfilling; (2) water virtually free of solids and oils which can be processed in an industrial or public wastewater treatment facility; and, (3) oil indigenous to the feed, a mixture of extracted hydrocarbon-soluble compounds which typically includes any hazardous contaminants which are present. As normally practices, this dehydration/solvent extraction technology involves slurrying water-wet waste in a hydrocarbon solvent which extracts indigenous oil from contaminated solid particles and concentrates it in the solvent phase. Dehydration also takes place during the treatment; water is evaporated and condensed as a separate product. Dry solids are reslurried in fresh solvent one or more additional times depending on the degree of extraction required. Extracted solids are centrifuged away from the solvent and residual solvent in the centrifuge cake vaporized off the final product solids stream in a desolventizer. Indigenous oil from the waste is separated from the solvent by distillation with recovered solvent being recycled to the process. This paper discusses the C-G Process flexibility and economics as applied to various hazardous waste examples including PCB contaminated sediments, soils and sludges, spent drilling fluids (US EPA SITE Program), refinery wastes, manufactured gas plant (MGP) sites, etc. 8 refs., 1 fig., 9 tabs.

  12. Solar Junction | Open Energy Information

    Open Energy Info (EERE)

    Junction Jump to: navigation, search Name: Solar Junction Place: San Jose, California Zip: CA 95131 Sector: Efficiency, Solar Product: Solar Junction is developing high efficiency...

  13. Building America Case Study: Solar Water Heating in Multifamily Buildings, Greenfield, Massachusetts (Fact Sheet), Efficient Solutions for Existing Homes, Energy Efficiency & Renewable Energy (EERE)

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

    Solar Water Heating in Multifamily Buildings Greenfield, Massachusetts PROJECT INFORMATION Construction: Gut rehab Type: Multifamily Builder: Olive Street Development Partner: Consortium for Advanced Residential Buildings, carb-swa.com Size: 372 ft 2 evacuated tube, 330 gallons storage Price: $31,000 before incentives Incentives Used: * Commonwealth Solar Hot Water Program * 30% Federal tax credit * Modified Accelerated Cost Recovery System (MACRS) * MassSave New Construction program Date

  14. DOE - Office of Legacy Management -- Grand Junction Sites

    Office of Legacy Management (LM)

    Grand Junction Sites Grand Junction Sites gjmap Grand Junction Disposal Site Grand Junction Processing Site Grand Junction Site Contact Us

  15. THERMAL EVALUATION OF THE CONCEPTUAL DHLW DISPOSAL CONTAINER LOADED WITH PU/CS GREENFIELD GLASS (SCPB: N/A)

    SciTech Connect (OSTI)

    T.L. Lotz

    1995-11-13

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) as specified in the Waste Package Implementation Plan (pp. 4-8,4-11,4-24,5-1, and 5-13; Ref. 5.10) and Waste Package Plan (pp. 3-15,3-17, and 3-24; Ref. 5.9). The design data request addressed herein is: Characterize the conceptual Defense High Level Waste (DHLW) Disposal Container design to show that the design is feasible for use in the MGDS environment when loaded with a plutonium/cesium greenfield glass waste form. The purpose of this analysis is to respond to a concern that the long-term disposal thermal issues for the conceptual DHLW disposal container design do not preclude compatibility with the MGDS if it is loaded with alternate waste forms. The objective of this analysis is to provide thermal parameter information for the conceptual DHLW disposal container design loaded with an alternative waste form containing a plutonium/cesium mixture under nominal MGDS repository conditions. The results are intended to show that the design loaded with this alternative waste form has a reasonable chance to meet the MGDS design requirements for normal MGDS operation and to provide the required guidance to determining the major design issues for future design efforts. Future design efforts will focus on specific DHLW vendor designs and improved waste form data when they become available.

  16. Three-junction solar cell

    DOE Patents [OSTI]

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  17. High-Intensity Silicon Vertical Multi-Junction Solar Cells |...

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

    ... Versatility Can be used in ground-mounted and roof-mounted deployments. Contact Information Mico Perales (216) 535-9200 mico.perales@greenfieldsolar.com GreenField Solar ...

  18. Junction Hilltop Wind | Open Energy Information

    Open Energy Info (EERE)

    navigation, search Name Junction Hilltop Wind Facility Junction Hilltop Wind Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Community Owned...

  19. Josephson junction Q-spoiler

    DOE Patents [OSTI]

    Clarke, John; Hilbert, Claude; Hahn, Erwin L.; Sleator, Tycho

    1988-01-01

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  20. Josephson junction Q-spoiler

    DOE Patents [OSTI]

    Clarke, J.; Hilbert, C.; Hahn, E.L.; Sleator, T.

    1986-03-25

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  1. Grand Junction Office Founder Honored...

    Energy Savers [EERE]

    4 Grand Junction Office Founder Honored at the Philip C. Leahy Memorial Park Dedication and Open House The U.S. Department of Energy (DOE) Offce of Legacy Management (LM) held an ...

  2. Electronic thermometry in tunable tunnel junction

    DOE Patents [OSTI]

    Maksymovych, Petro

    2016-03-15

    A tunable tunnel junction thermometry circuit includes a variable width tunnel junction between a test object and a probe. The junction width is varied and a change in thermovoltage across the junction with respect to the change in distance across the junction is determined. Also, a change in biased current with respect to a change in distance across the junction is determined. A temperature gradient across the junction is determined based on a mathematical relationship between the temperature gradient, the change in thermovoltage with respect to distance and the change in biased current with respect to distance. Thermovoltage may be measured by nullifying a thermoelectric tunneling current with an applied voltage supply level. A piezoelectric actuator may modulate the probe, and thus the junction width, to vary thermovoltage and biased current across the junction. Lock-in amplifiers measure the derivatives of the thermovoltage and biased current modulated by varying junction width.

  3. Annual Inspection of the Grand Junction, Colorado, Site

    Office of Legacy Management (LM)

    6 Annual Inspection - Grand Junction, Colorado, Office Site April 2016 Page 1 Annual Inspection of the Grand Junction, Colorado, Site 1.1 Inspection Summary The Grand Junction, ...

  4. Greenfield Solar | Open Energy Information

    Open Energy Info (EERE)

    Place: Oberlin, Ohio Product: Developer of combined hot water and concentrator photovoltaic systems using in-house, proprietary cell architecture. Coordinates: 41.292925,...

  5. Grand Junction, Colorado, Site Fact Sheet

    Office of Legacy Management (LM)

    D D&D Page 1 of 3 Fact Sheet Grand Junction, Colorado, Site This fact sheet provides information about the Grand Junction, Colorado, Site. This site is managed by the U.S. ...

  6. DOE Grand Junction Projects Office Edgemont LTSP

    Office of Legacy Management (LM)

    DOE Grand Junction Projects Office Edgemont LTSP June 1996 Page ii Contents Page 1.0 Introduction ......

  7. Grundy County, Tennessee: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 35.4013452, -85.684578 Show Map Loading map... "minzoom":false,"mappingservice":"googl...

  8. Grundy County, Illinois: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Illinois: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 41.3500531, -88.4016041 Show Map Loading map... "minzoom":false,"mappingservice":"goo...

  9. Grundy County Rural Elec Coop | Open Energy Information

    Open Energy Info (EERE)

    Elec Coop Place: Iowa Phone Number: 319-824-5251 Website: www.grundycountyrecia.com Outage Hotline: 1-800-390-7605 Outage Map: www.iowarec.orgoutages References: EIA Form...

  10. Method for shallow junction formation

    DOE Patents [OSTI]

    Weiner, K.H.

    1996-10-29

    A doping sequence is disclosed that reduces the cost and complexity of forming source/drain regions in complementary metal oxide silicon (CMOS) integrated circuit technologies. The process combines the use of patterned excimer laser annealing, dopant-saturated spin-on glass, silicide contact structures and interference effects creates by thin dielectric layers to produce source and drain junctions that are ultrashallow in depth but exhibit low sheet and contact resistance. The process utilizes no photolithography and can be achieved without the use of expensive vacuum equipment. The process margins are wide, and yield loss due to contact of the ultrashallow dopants is eliminated. 8 figs.

  11. Method for shallow junction formation

    DOE Patents [OSTI]

    Weiner, Kurt H.

    1996-01-01

    A doping sequence that reduces the cost and complexity of forming source/drain regions in complementary metal oxide silicon (CMOS) integrated circuit technologies. The process combines the use of patterned excimer laser annealing, dopant-saturated spin-on glass, silicide contact structures and interference effects creates by thin dielectric layers to produce source and drain junctions that are ultrashallow in depth but exhibit low sheet and contact resistance. The process utilizes no photolithography and can be achieved without the use of expensive vacuum equipment. The process margins are wide, and yield loss due to contact of the ultrashallow dopants is eliminated.

  12. Solar Junction Develops World Record Setting Concentrated Photovoltaic...

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

    Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell April 18, 2013 - ...

  13. Preservationists Tour Historic Log Cabin at the Grand Junction...

    Office of Environmental Management (EM)

    Preservationists Tour Historic Log Cabin at the Grand Junction, Colorado, Office Preservationists Tour Historic Log Cabin at the Grand Junction, Colorado, Office April 19, 2016 - ...

  14. Grand Junction Office Founder Honored at the Philip C. Leahy...

    Office of Environmental Management (EM)

    Grand Junction Office Founder Honored at the Philip C. Leahy Memorial Park Dedication and Open House Grand Junction Office Founder Honored at the Philip C. Leahy Memorial Park ...

  15. Students from Grand Junction High School Triumph in Colorado...

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

    Grand Junction High School Triumph in Colorado Science Bowl For more information contact: e:mail: Public Affairs Golden, Colo., Feb. 12, 2000 - Students from Grand Junction High ...

  16. Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin...

    Office of Scientific and Technical Information (OSTI)

    Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin Temperatures Title: Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin Temperatures ...

  17. Silicon fiber with p-n junction

    SciTech Connect (OSTI)

    Homa, D.; Cito, A.; Pickrell, G.; Hill, C.; Scott, B.

    2014-09-22

    In this study, we fabricated a p-n junction in a fiber with a phosphorous doped silicon core and fused silica cladding. The fibers were fabricated via a hybrid process of the core-suction and melt-draw techniques and maintained overall diameters ranging from 200 to 900??m and core diameters of 20800??m. The p-n junction was formed by doping the fiber with boron and confirmed via the current-voltage characteristic. The demonstration of a p-n junction in a melt-drawn silicon core fiber paves the way for the seamless integration of optical and electronic devices in fibers.

  18. Tunnel junction multiple wavelength light-emitting diodes

    DOE Patents [OSTI]

    Olson, Jerry M.; Kurtz, Sarah R.

    1992-01-01

    A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

  19. Tunnel junction multiple wavelength light-emitting diodes

    DOE Patents [OSTI]

    Olson, J.M.; Kurtz, S.R.

    1992-11-24

    A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.

  20. Semiconductor tunnel junction with enhancement layer

    DOE Patents [OSTI]

    Klem, John F.; Zolper, John C.

    1997-01-01

    The incorporation of a pseudomorphic GaAsSb layer in a runnel diode structure affords a new degree of freedom in designing runnel junctions for p-n junction device interconnects. Previously only doping levels could be varied to control the tunneling properties. This invention uses the valence band alignment band of the GaAsSb with respect to the surrounding materials to greatly relax the doping requirements for tunneling.

  1. Semiconductor tunnel junction with enhancement layer

    DOE Patents [OSTI]

    Klem, J.F.; Zolper, J.C.

    1997-10-21

    The incorporation of a pseudomorphic GaAsSb layer in a runnel diode structure affords a new degree of freedom in designing runnel junctions for p-n junction device interconnects. Previously only doping levels could be varied to control the tunneling properties. This invention uses the valence band alignment band of the GaAsSb with respect to the surrounding materials to greatly relax the doping requirements for tunneling. 5 figs.

  2. Multi-junction solar cell device

    DOE Patents [OSTI]

    Friedman, Daniel J.; Geisz, John F.

    2007-12-18

    A multi-junction solar cell device (10) is provided. The multi-junction solar cell device (10) comprises either two or three active solar cells connected in series in a monolithic structure. The multi-junction device (10) comprises a bottom active cell (20) having a single-crystal silicon substrate base and an emitter layer (23). The multi-junction device (10) further comprises one or two subsequent active cells each having a base layer (32) and an emitter layer (23) with interconnecting tunnel junctions between each active cell. At least one layer that forms each of the top and middle active cells is composed of a single-crystal III-V semiconductor alloy that is substantially lattice-matched to the silicon substrate (22). The polarity of the active p-n junction cells is either p-on-n or n-on-p. The present invention further includes a method for substantially lattice matching single-crystal III-V semiconductor layers with the silicon substrate (22) by including boron and/or nitrogen in the chemical structure of these layers.

  3. A single-gradient junction technique to replace multiple-junction shifts for craniospinal irradiation treatment

    SciTech Connect (OSTI)

    Hadley, Austin; Ding, George X.

    2014-01-01

    Craniospinal irradiation (CSI) requires abutting fields at the cervical spine. Junction shifts are conventionally used to prevent setup errorinduced overdosage/underdosage from occurring at the same location. This study compared the dosimetric differences at the cranial-spinal junction between a single-gradient junction technique and conventional multiple-junction shifts and evaluated the effect of setup errors on the dose distributions between both techniques for a treatment course and single fraction. Conventionally, 2 lateral brain fields and a posterior spine field(s) are used for CSI with weekly 1-cm junction shifts. We retrospectively replanned 4 CSI patients using a single-gradient junction between the lateral brain fields and the posterior spine field. The fields were extended to allow a minimum 3-cm field overlap. The dose gradient at the junction was achieved using dose painting and intensity-modulated radiation therapy planning. The effect of positioning setup errors on the dose distributions for both techniques was simulated by applying shifts of 3 and 5 mm. The resulting cervical spine doses across the field junction for both techniques were calculated and compared. Dose profiles were obtained for both a single fraction and entire treatment course to include the effects of the conventional weekly junction shifts. Compared with the conventional technique, the gradient-dose technique resulted in higher dose uniformity and conformity to the target volumes, lower organ at risk (OAR) mean and maximum doses, and diminished hot spots from systematic positioning errors over the course of treatment. Single-fraction hot and cold spots were improved for the gradient-dose technique. The single-gradient junction technique provides improved conformity, dose uniformity, diminished hot spots, lower OAR mean and maximum dose, and one plan for the entire treatment course, which reduces the potential human error associated with conventional 4-shifted plans.

  4. Methods for the fabrication of thermally stable magnetic tunnel junctions

    DOE Patents [OSTI]

    Chang, Y. Austin; Yang, Jianhua J.; Ladwig, Peter F.

    2009-08-25

    Magnetic tunnel junctions and method for making the magnetic tunnel junctions are provided. The magnetic tunnel junctions are characterized by a tunnel barrier oxide layer sandwiched between two ferromagnetic layers. The methods used to fabricate the magnetic tunnel junctions are capable of completely and selectively oxidizing a tunnel junction precursor material using an oxidizing gas containing a mixture of gases to provide a tunnel junction oxide without oxidizing the adjacent ferromagnetic materials. In some embodiments the gas mixture is a mixture of CO and CO.sub.2 or a mixture of H.sub.2 and H.sub.2O.

  5. Junction-side illuminated silicon detector arrays

    DOE Patents [OSTI]

    Iwanczyk, Jan S.; Patt, Bradley E.; Tull, Carolyn

    2004-03-30

    A junction-side illuminated detector array of pixelated detectors is constructed on a silicon wafer. A junction contact on the front-side may cover the whole detector array, and may be used as an entrance window for light, x-ray, gamma ray and/or other particles. The back-side has an array of individual ohmic contact pixels. Each of the ohmic contact pixels on the back-side may be surrounded by a grid or a ring of junction separation implants. Effective pixel size may be changed by separately biasing different sections of the grid. A scintillator may be coupled directly to the entrance window while readout electronics may be coupled directly to the ohmic contact pixels. The detector array may be used as a radiation hardened detector for high-energy physics research or as avalanche imaging arrays.

  6. Complementary junction heterostructure field-effect transistor

    DOE Patents [OSTI]

    Baca, Albert G.; Drummond, Timothy J.; Robertson, Perry J.; Zipperian, Thomas E.

    1995-01-01

    A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits.

  7. Complementary junction heterostructure field-effect transistor

    DOE Patents [OSTI]

    Baca, A.G.; Drummond, T.J.; Robertson, P.J.; Zipperian, T.E.

    1995-12-26

    A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits. 10 figs.

  8. Fluctuation of heat current in Josephson junctions

    SciTech Connect (OSTI)

    Virtanen, P.; Giazotto, F.

    2015-02-15

    We discuss the statistics of heat current between two superconductors at different temperatures connected by a generic weak link. As the electronic heat in superconductors is carried by Bogoliubov quasiparticles, the heat transport fluctuations follow the Levitov–Lesovik relation. We identify the energy-dependent quasiparticle transmission probabilities and discuss the resulting probability density and fluctuation relations of the heat current. We consider multichannel junctions, and find that heat transport in diffusive junctions is unique in that its statistics is independent of the phase difference between the superconductors.

  9. Grand Junction, Colorado, Processing Site and Disposal Sites Fact Sheet

    Office of Legacy Management (LM)

    Grand Junction, Colorado, Disposal and Processing Sites This fact sheet provides information about the Uranium Mill Tailings Radiation Control Act of 1978 Title I disposal and processing sites at Grand Junction, Colorado. These sites are managed by the U.S. Department of Energy Office of Legacy Management. Locations of the Grand Junction, Colorado, Sites Site Description and History The former Grand Junction processing site, historically known as the Climax uranium mill, sits at an elevation of

  10. High voltage series connected tandem junction solar battery

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1982-01-01

    A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

  11. Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell

    Broader source: Energy.gov [DOE]

    EERE supported the development of Solar Junction's concentrated photovoltaic technology that set a world record for conversion efficiency.

  12. Tandem junction amorphous silicon solar cells

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1981-01-01

    An amorphous silicon solar cell has an active body with two or a series of layers of hydrogenated amorphous silicon arranged in a tandem stacked configuration with one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon arranged in tandem configuration can have the same bandgap or differing bandgaps.

  13. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, J.C.; Shul, R.J.

    1999-02-02

    An ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same are disclosed. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorus co-implantation, in selected III-V semiconductor materials. 19 figs.

  14. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, John C.; Shul, Randy J.

    1999-01-01

    An all-ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorous co-implantation, in selected III-V semiconductor materials.

  15. Semiconductor liquid-junction solar cell

    SciTech Connect (OSTI)

    Parkinson, B.A.

    1982-10-29

    A semiconductor liquid junction photocell in which the photocell is in the configuration of a light concentrator and in which the electrolytic solution both conducts current and facilitates the concentration of incident solar radiation onto the semiconductor. The photocell may be in the configuration of a non-imaging concentrator such as a compound parabolic concentrator, or an imaging concentrator such as a lens.

  16. EA-0930: Facility Operations at the U.S. DOE Grand Junction Projects Office, Grand Junction, Colorado

    Office of Energy Efficiency and Renewable Energy (EERE)

    This EA evaluates the environmental impacts of the proposal to expand and upgrade the U.S. Department of Energy's Grand Junction Projects Office facilities and operations in Grand Junction, Colorado.

  17. Greenfield, Massachusetts: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Massachusetts: Energy Resources Jump to: navigation, search This article is a stub. You can help OpenEI by expanding it. Equivalent URI DBpedia Coordinates 42.5875857,...

  18. QER- Comment of Solar Store of Greenfield

    Broader source: Energy.gov [DOE]

    I speak for many millions of Americans who are ready and able to more the USA towards that goal of 100% renewables by 2050. WE are ready to START TODAY. And in fact we have started already. Thank you for your time and consideration. Claire Chang

  19. Junction conditions in extended Teleparallel gravities

    SciTech Connect (OSTI)

    De la Cruz-Dombriz, lvaro; Dunsby, Peter K.S.; Sez-Gmez, Diego E-mail: peter.dunsby@uct.ac.za

    2014-12-01

    In the context of extended Teleparallel gravity theories, we address the issue of junction conditions required to guarantee the correct matching of different regions of spacetime. In the absence of shells/branes, these conditions turn out to be more restrictive than their counterparts in General Relativity as in other extended theories of gravity. In fact, the general junction conditions on the matching hypersurfaces depend on the underlying theory and a new condition on the induced tetrads in order to avoid delta-like distributions in the field equations. This result imposes strict consequences on the viability of standard solutions such as the Einstein-Straus-like construction. We find that the continuity of the scalar torsion is required in order to recover the usual General Relativity results.

  20. Semiconductor junction formation by directed heat

    DOE Patents [OSTI]

    Campbell, Robert B.

    1988-03-24

    The process of the invention includes applying precursors 6 with N- and P-type dopants therein to a silicon web 2, with the web 2 then being baked in an oven 10 to drive off excessive solvents, and the web 2 is then heated using a pulsed high intensity light in a mechanism 12 at 1100.degree.-1150.degree. C. for about 10 seconds to simultaneously form semiconductor junctions in both faces of the web.

  1. Highly Charged Ion (HCI) Modified Tunnel Junctions

    SciTech Connect (OSTI)

    Pomeroy, J. M.; Grube, H. [Atomic Physics Division, National Institute of Standards and Technology (NIST) 100 Bureau Dr., MS 8423, Gaithersburg, MD 20899-8423 (United States)

    2009-03-10

    The neutralization energy carried by highly charged ions (HCIs) provides an alternative method for localizing energy on a target's surface, producing features and modifying surfaces with fluences and kinetic energy damage that are negligible compared to singly ionized atoms. Since each HCI can deposit an enormous amount of energy into a small volume of the surface (e.g., Xe{sup 44+} delivers 51 keV of neutralization energy per HCI), each individual HCI's interaction with the target can produce a nanoscale feature. Many studies of HCI-surface features have characterized some basic principles of this unique ion-surface interaction, but the activity reported here has been focused on studying ensembles of HCI features in ultra-thin insulating films by fabricating multi-layer tunnel junction devices. The ultra-thin insulating barriers allow current to flow by tunneling, providing a very sensitive means of detecting changes in the barrier due to highly charged ion irradiation and, conversely, HCI modification provides a method of finely tuning the transparency of the tunnel junctions that spans several orders of magnitude for devices produced from a single process recipe. Systematic variation of junction bias, temperature, magnetic field and other parameters provides determination of the transport mechanism, defect densities, and magnetic properties of these nano-features and this novel approach to device fabrication.

  2. DOE - Office of Legacy Management -- Climax Uranium Co Grand Junction Mill

    Office of Legacy Management (LM)

    - CO 0-03 Climax Uranium Co Grand Junction Mill - CO 0-03 FUSRAP Considered Sites Site: Climax Uranium Co. (Grand Junction Mill) (CO.0-03) Licensed to DOE for long-term custody and managed by the Office of Legacy Management. Designated Name: Grand Junction, Colorado, Processing Site Alternate Name: Climax Uranium Company (Grand Junction Mill) Grand Junction Uranium Mill Tailings Remedial Action Site Climax Mill Site Grand Junction Mill 1 Location: Grand Junction, Colorado Evaluation Year:

  3. Single P-N junction tandem photovoltaic device

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw; Ager, III, Joel W.; Yu, Kin Man

    2012-03-06

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  4. Single P-N junction tandem photovoltaic device

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw; Ager, III, Joel W.; Yu, Kin Man

    2011-10-18

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  5. 2012 Annual Inspection Report for the Grand Junction, Colorado, Site

    Office of Legacy Management (LM)

    Annual Inspection - Grand Junction, Colorado, Site March 2012 Page 1 2012 Annual Inspection Report for the Grand Junction, Colorado, Site Summary The Grand Junction, Colorado, Site was inspected on February 23, 2012, and was in excellent condition. Physical and institutional controls enacted at the site continue to be effective in preventing exposure to contamination remaining on the property. A 5-year deficiency-based inspection of all real property assets in compliance with DOE Order 430.1B

  6. 2013 Annual Inspection Report for the Grand Junction, Colorado, Site

    Office of Legacy Management (LM)

    Annual Inspection - Grand Junction, Colorado, Site April 2013 Page 1 2013 Annual Inspection Report for the Grand Junction, Colorado, Site Summary The Grand Junction, Colorado, Site was inspected on March 4, 2013, and was in excellent condition. Physical and institutional controls enacted at the site continue to be effective in preventing exposure to contamination remaining on the property. No cause for a follow-up inspection was identified. 1.0 Introduction This report presents the results of

  7. Annual Inspection of the Grand Junction, Colorado, Site

    Office of Legacy Management (LM)

    Grand Junction, Colorado, Office Site March 2014 Page 1 Annual Inspection of the Grand Junction, Colorado, Site 1.1 Inspection Summary The Grand Junction, Colorado, Site was inspected on February 19, 2014, and was in excellent condition. Physical and institutional controls enacted at the site continue to be effective in preventing exposure to contamination remaining on the property. No maintenance needs were identified and no cause for a follow-up inspection was identified. The site was

  8. Annual Inspection of the Grand Junction, Colorado, Site

    Office of Legacy Management (LM)

    Grand Junction, Colorado, Office Site March 2015 Page 1 Annual Inspection of the Grand Junction, Colorado, Site 1.1 Inspection Summary The Grand Junction, Colorado, Site was inspected on February 18, 2015, and was in good condition. Physical and institutional controls enacted at the site continue to be effective in preventing exposure to contamination remaining on the property. Two minor maintenance needs were identified; however, no cause for a follow-up inspection was identified. The site was

  9. Electromagnetic squeezer for compressing squeezable electron tunneling junctions. Technical report

    SciTech Connect (OSTI)

    Moreland, J.; Hansma, P.K.

    1984-01-01

    The resistance of squeezable electron tunnel junctions (SET junctions) can be adjusted with an electromagnetic squeezer. For junctions immersed in liquid helium, the resistance is stable to approximately 0.1%. This stability is sufficient for measurements of superconducting energy gaps and for superconducting phonon spectroscopy out to 50 mV applied bias. Increased stability, especially at higher biases, will be necessary for inelastic electron tunneling spectroscopy.

  10. Electromagnetic squeezer for compressing squeezable electron tunnelling junctions

    SciTech Connect (OSTI)

    Moreland, J.; Hansma, P.K.

    1984-03-01

    The resistance of squeezable electron tunnel junctions (SET junctions) can be adjusted with an electromagnetic squeezer. For junctions immersed in liquid helium, the resistance is stable to approximately 0.1%. This stability is sufficient for measurements of superconducting energy gaps and for superconducting phonon spectroscopy out to 50-mV applied bias. Increased stability, especially at higher biases, will be necessary for inelastic electron tunnelling spectroscopy.

  11. DNA Gridiron Nanostructures Based on Four-Arm Junctions

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

    DNA Gridiron Nanostructures Based on Four-Arm Junctions Authors: Han, D., Pal, S., Yang, Y., Jiang, S., Nangreave, J., Liu, Y., and Yan, H. Title: DNA Gridiron Nanostructures Based on Four-Arm Junctions Source: Science Year: 2013 Volume: 339 Pages: 1412-1415 ABSTRACT: Engineering wireframe architectures and scaffolds of increasing complexity is one of the important challenges in nanotechnology. We present a design strategy to create gridiron-like DNA structures. A series of four-arm junctions

  12. Superconductive tunnel junction device and method of manufacture

    SciTech Connect (OSTI)

    Kroger, H.

    1983-12-20

    A Josephson tunnel junction device having niobium nitride superconductive electrodes includes a polycrystalline semiconductor tunneling barrier therebetween comprised of silicon, germanium, or an alloy thereof preferably deposited on the lower superconductive electrodes by vapor deposition. The barrier thickness of the junction is controlled by precision doping of the semiconductor material. The active junction is defined after the interfaces between the barrier material and the two superconductor lines are formed, retaining those active interfaces in fully unpolluted character.

  13. Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

    DOE Patents [OSTI]

    Chang, Y. Austin; Yang, Jianhua Joshua

    2008-11-11

    This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

  14. Van der Waals metal-semiconductor junction: Weak Fermi level...

    Office of Scientific and Technical Information (OSTI)

    Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier Citation Details In-Document Search Title: Van der Waals ...

  15. Apache Junction, Arizona: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Junction, Arizona: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 33.4150485, -111.5495777 Show Map Loading map... "minzoom":false,"mappingser...

  16. City of Grand Junction, Iowa (Utility Company) | Open Energy...

    Open Energy Info (EERE)

    Iowa (Utility Company) Jump to: navigation, search Name: Grand Junction Municipal Utilities Place: Iowa Phone Number: (515) 738-2285 or (515) 738-2726 Facebook: https:...

  17. Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin

    Office of Scientific and Technical Information (OSTI)

    Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin Temperatures Borzenets, I. V.; Coskun, U. C.; Mebrahtu, H. T.; Bomze, Yu. V.; Smirnov, A. I.; Finkelstein, G....

  18. Hetero-junctions of Boron Nitride and Carbon Nanotubes: Synthesis...

    Office of Scientific and Technical Information (OSTI)

    3) quantum dots functionalized BNNTs (QDs-BNNTs), 4) BNNTgraphene junctions. We have started to understand their structural, compositional, more and electronic properties. ...

  19. Grand Junction, Colorado: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    district.12 Registered Energy Companies in Grand Junction, Colorado Ruby Canyon Engineering Inc References US Census Bureau Incorporated place and minor civil...

  20. Phonon interference effects in molecular junctions

    SciTech Connect (OSTI)

    Markussen, Troels

    2013-12-28

    We study coherent phonon transport through organic, ?-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in similar molecules. The destructive interference features observed in four different cross-conjugated molecules significantly reduce the thermal conductance with respect to linear conjugated analogues. Such control of the thermal conductance by chemical modifications could be important for thermoelectric applications of molecular junctions.

  1. Subgap biasing of superconducting tunnel junctions without a magnetic field

    SciTech Connect (OSTI)

    Segall, K.; Moyer, J.; Mazo, Juan J.

    2008-08-15

    Superconducting tunnel junctions (STJs) have been successfully used as single-photon detectors but require the use of a magnetic field to operate. A recent paper has proposed the idea to use a circuit of three junctions in place of a single junction in order to achieve the necessary biasing without applying a magnetic field. The nonlinear interaction between the different junctions in the circuit causes the existence of a stable subgap state for one of the junctions, which acts as the detector junction. In this paper, we present the first measurements demonstrating the existence of such a biasing state feasible for STJ detectors. Single junction measurements with an applied magnetic field help determine the functional form of the subgap current versus voltage; then the operating point of a three-junction circuit is measured and fit to theory. The excellent match between theory and experiment demonstrates the existence of the subgap biasing state. The outlook for possible use in detector applications is discussed.

  2. Josephson junctions in high-T/sub c/ superconductors

    DOE Patents [OSTI]

    Falco, C.M.; Lee, T.W.

    1981-01-14

    The invention includes a high T/sub c/ Josephson sperconducting junction as well as the method and apparatus which provides the junction by application of a closely controlled and monitored electrical discharge to a microbridge region connecting two portions of a superconducting film.

  3. Data Compendium for the Logging Test Pits at the ERDA Grand Junction...

    Office of Environmental Management (EM)

    Data Compendium for the Logging Test Pits at the ERDA Grand Junction Compound (December 1975) Data Compendium for the Logging Test Pits at the ERDA Grand Junction Compound ...

  4. Phase diagram of Josephson junction between s and s ± superconductors...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Phase diagram of Josephson junction between s and s superconductors in the dirty limit Title: Phase diagram of Josephson junction between s and ...

  5. Field-effect P-N junction

    DOE Patents [OSTI]

    Regan, William; Zettl, Alexander

    2015-05-05

    This disclosure provides systems, methods, and apparatus related to field-effect p-n junctions. In one aspect, a device includes an ohmic contact, a semiconductor layer disposed on the ohmic contact, at least one rectifying contact disposed on the semiconductor layer, a gate including a layer disposed on the at least one rectifying contact and the semiconductor layer and a gate contact disposed on the layer. A lateral width of the rectifying contact is less than a semiconductor depletion width of the semiconductor layer. The gate contact is electrically connected to the ohmic contact to create a self-gating feedback loop that is configured to maintain a gate electric field of the gate.

  6. Mechanical deformations of boron nitride nanotubes in crossed junctions

    SciTech Connect (OSTI)

    Zhao, Yadong; Chen, Xiaoming; Ke, Changhong; Park, Cheol; Fay, Catharine C.; Stupkiewicz, Stanislaw

    2014-04-28

    We present a study of the mechanical deformations of boron nitride nanotubes (BNNTs) in crossed junctions. The structure and deformation of the crossed tubes in the junction are characterized by using atomic force microscopy. Our results show that the total tube heights are reduced by 20%33% at the crossed junctions formed by double-walled BNNTs with outer diameters in the range of 2.214.67?nm. The measured tube height reduction is found to be in a nearly linear relationship with the summation of the outer diameters of the two tubes forming the junction. The contact force between the two tubes in the junction is estimated based on contact mechanics theories and found to be within the range of 4.27.6 nN. The Young's modulus of BNNTs and their binding strengths with the substrate are quantified, based on the deformation profile of the upper tube in the junction, and are found to be 1.07??0.11 TPa and 0.180.29 nJ/m, respectively. Finally, we perform finite element simulations on the mechanical deformations of the crossed BNNT junctions. The numerical simulation results are consistent with both the experimental measurements and the analytical analysis. The results reported in this paper contribute to a better understanding of the structural and mechanical properties of BNNTs and to the pursuit of their applications.

  7. Effect of current injection into thin-film Josephson junctions

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

    Kogan, V. G.; Mints, R. G.

    2014-11-11

    New thin-film Josephson junctions have recently been tested in which the current injected into one of the junction banks governs Josephson phenomena. One thus can continuously manage the phase distribution at the junction by changing the injected current. Our method of calculating the distribution of injected currents is also proposed for a half-infinite thin-film strip with source-sink points at arbitrary positions at the film edges. The strip width W is assumed small relative to Λ=2λ2/d;λ is the bulk London penetration depth of the film material and d is the film thickness.

  8. Effect of current injection into thin-film Josephson junctions

    SciTech Connect (OSTI)

    Kogan, V. G.; Mints, R. G.

    2014-11-11

    New thin-film Josephson junctions have recently been tested in which the current injected into one of the junction banks governs Josephson phenomena. One thus can continuously manage the phase distribution at the junction by changing the injected current. Our method of calculating the distribution of injected currents is also proposed for a half-infinite thin-film strip with source-sink points at arbitrary positions at the film edges. The strip width W is assumed small relative to Λ=2λ2/d;λ is the bulk London penetration depth of the film material and d is the film thickness.

  9. Selective niobium anodization process for fabricating Josephson tunnel junctions

    SciTech Connect (OSTI)

    Kroger, H.; Smith, L.N.; Jillie, D.W.

    1981-08-01

    A novel process for fabricating refractory sperconducting tunnel junctions is described, which is useful with both deposited and native oxide barriers. The distinguishing feature of the method is that the entire superconductor-barrier-superconductor sandwich is formed before the patterning of any layer. Isolated Josephson junctions are then formed by anodizing through the upper electrode, while the devices themselves are protected by a photoresist mask. Using this process, Nb-Si:H-Nb junctions have been fabricated, whose product of critical current and subgap resistance exceeds 10 mV and whose critical current density varies by about 50% over a 2-in. diameter wafer.

  10. RESULTS OF RADIOLOGICAL MEASUREMENTS TAKEN NEAR JUNCTION OF HIGHWAY...

    Office of Legacy Management (LM)

    RESULTS OF RADIOLOGICAL MEASUREMENTS TAKEN NEAR JUNCTION OF HIGHWAY 3I AND MILITARY ROAD ... RESULTS OF RADIOLOGTCAL ITEASUREMENfi| TAKEN NEAR JUNCTToN 9F HIGESAY 31 AT.ID MILITARY ...

  11. In the OSTI Collections: Josephson Junctions | OSTI, US Dept...

    Office of Scientific and Technical Information (OSTI)

    ... in ferromagnetic Josephson junctions"DoE PAGES. (a) A niobium base layer 150 nanometers thick. (b) A niobium-aluminum-niobium-gold multilayer stack 87.4 nanometers thick. ...

  12. Coso Junction, California: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    OpenEI by expanding it. Coso Junction is a city in Inyo County, California. It is in Rose Valley, south of Dunmovin and west of Sugarloaf Mountain.1 Energy Generation...

  13. White River Junction, Vermont: Energy Resources | Open Energy...

    Open Energy Info (EERE)

    Hide Map This article is a stub. You can help OpenEI by expanding it. White River Junction is a census-designated place in Windsor County, Vermont. It falls under...

  14. Manipulating Josephson junctions in thin-films by nearby vortices

    SciTech Connect (OSTI)

    Kogan, V G; Mints, R G

    2014-07-01

    It is shown that a vortex trapped in one of the banks of a planar edge-type Josephson junction in a narrow thin-film superconducting strip can change drastically the dependence of the junction critical current on the applied field, I-c(H). When the vortex is placed at certain discrete positions in the strip middle, the pattern I-c(H) has zero at H = 0 instead of the traditional maximum of '0-type' junctions. The number of these positions is equal to the number of vortices trapped at the same location. When the junction-vortex separation exceeds similar to W, the strip width, I-c(H) is no longer sensitive to the vortex presence. The same is true for any separation if the vortex approaches the strip edges. (C) 2014 Elsevier B.V. All rights reserved.

  15. Single-charge detection by an atomic precision tunnel junction

    SciTech Connect (OSTI)

    House, M. G. Peretz, E.; Keizer, J. G.; Hile, S. J.; Simmons, M. Y.

    2014-03-17

    We demonstrate sensitive detection of single charges using a planar tunnel junction 8.5?nm wide and 17.2?nm long defined by an atomically precise phosphorus doping profile in silicon. The conductance of the junction responds to a nearby gate potential and also to changes in the charge state of a quantum dot patterned 52?nm away. The response of this detector is monotonic across the entire working voltage range of the device, which will make it particularly useful for studying systems of multiple quantum dots. The charge sensitivity is maximized when the junction is most conductive, suggesting that more sensitive detection can be achieved by shortening the length of the junction to increase its conductance.

  16. Phase diagram of Josephson junction between

    Office of Scientific and Technical Information (OSTI)

    diagram of Josephson junction betweensandssuperconductors in the dirty limit...

  17. Tunnel junction enhanced nanowire ultraviolet light emitting diodes

    SciTech Connect (OSTI)

    Sarwar, A. T. M. Golam; May, Brelon J.; Deitz, Julia I.; Grassman, Tyler J.; McComb, David W.; Myers, Roberto C.

    2015-09-07

    Polarization engineered interband tunnel junctions (TJs) are integrated in nanowire ultraviolet (UV) light emitting diodes (LEDs). A ∼6 V reduction in turn-on voltage is achieved by the integration of tunnel junction at the base of polarization doped nanowire UV LEDs. Moreover, efficient hole injection into the nanowire LEDs leads to suppressed efficiency droop in TJ integrated nanowire LEDs. The combination of both reduced bias voltage and increased hole injection increases the wall plug efficiency in these devices. More than 100 μW of UV emission at ∼310 nm is measured with external quantum efficiency in the range of 4–6 m%. The realization of tunnel junction within the nanowire LEDs opens a pathway towards the monolithic integration of cascaded multi-junction nanowire LEDs on silicon.

  18. EA-1037: Uranium Lease Management Program, Grand Junction, Colorado

    Office of Energy Efficiency and Renewable Energy (EERE)

    This EA evaluates the environmental impacts of the U.S. Department of Energy's Grand Junction Projects Office's proposal to maintain and preserve the nation's immediately accessible supply of...

  19. Heterojunction for Multi-Junction Solar Cells - Energy Innovation Portal

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

    Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Heterojunction for Multi-Junction Solar Cells Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (1,250 KB) Technology Marketing SummarySandia National Laboratories has created a semiconductor p-n heterojunction for use in forming a photodetector that has applications for use in a multi-junction solar cell and detecting light

  20. High Efficiency Multiple-Junction Solar Cells - Energy Innovation Portal

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

    Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search High Efficiency Multiple-Junction Solar Cells Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (937 KB) Technology Marketing SummarySingle junction solar cells have limited efficiency and fail to extract maximum energy from photons outside of a specific spectral region. Higher efficiency and optical to electrical energy conversion is achieved by stacking

    1. EA-1338: Transfer of the Department of Energy Grand Junction Office to Non-DOE Ownership, Grand Junction, Colorado

      Office of Energy Efficiency and Renewable Energy (EERE)

      This EA evaluates the environmental impacts for the proposed transfer of real and personal property at the U.S. Department of Energy's Grand Junction Office to non-DOE ownership.

    2. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

      SciTech Connect (OSTI)

      Beach, R.; Burdick, A.

      2014-03-01

      This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

    3. Junction-based field emission structure for field emission display

      DOE Patents [OSTI]

      Dinh, Long N.; Balooch, Mehdi; McLean, II, William; Schildbach, Marcus A.

      2002-01-01

      A junction-based field emission display, wherein the junctions are formed by depositing a semiconducting or dielectric, low work function, negative electron affinity (NEA) silicon-based compound film (SBCF) onto a metal or n-type semiconductor substrate. The SBCF can be doped to become a p-type semiconductor. A small forward bias voltage is applied across the junction so that electron transport is from the substrate into the SBCF region. Upon entering into this NEA region, many electrons are released into the vacuum level above the SBCF surface and accelerated toward a positively biased phosphor screen anode, hence lighting up the phosphor screen for display. To turn off, simply switch off the applied potential across the SBCF/substrate. May be used for field emission flat panel displays.

    4. Superpoissonian shot noise in organic magnetic tunnel junctions

      SciTech Connect (OSTI)

      Cascales, Juan Pedro; Martinez, Isidoro; Aliev, Farkhad G.; Hong, Jhen-Yong; Lin, Minn-Tsong; Szczepański, Tomasz; Dugaev, Vitalii K.; Barnaś, Józef

      2014-12-08

      Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here, we investigate conductance and shot noise in magnetic tunnel junctions with 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA) barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10% and 40%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5–2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

    5. Advanced materials development for multi-junction monolithic photovoltaic devices

      SciTech Connect (OSTI)

      Dawson, L.R.; Reno, J.L.

      1996-07-01

      We report results in three areas of research relevant to the fabrication of monolithic multi-junction photovoltaic devices. (1) The use of compliant intervening layers grown between highly mismatched materials, GaAs and GaP (same lattice constant as Si), is shown to increase the structural quality of the GaAs overgrowth. (2) The use of digital alloys applied to the MBE growth of GaAs{sub x}Sb{sub l-x} (a candidate material for a two junction solar cell) provides increased control of the alloy composition without degrading the optical properties. (3) A nitrogen plasma discharge is shown to be an excellent p-type doping source for CdTe and ZnTe, both of which are candidate materials for a two junction solar cell.

    6. Environmental Audit of the Grand Junction Projects Office

      SciTech Connect (OSTI)

      Not Available

      1991-08-01

      The Grand Junction Projects Office (GJPO) is located in Mesa County, Colorado, immediately south and west of the Grand Junction city limits. The US Atomic Energy Commission (AEC) established the Colorado Raw Materials Office at the present-day Grand Junction Projects Office in 1947, to aid in the development of a viable domestic uranium industry. Activities at the site included sampling uranium concentrate; pilot-plant milling research, including testing and processing of uranium ores; and operation of a uranium mill pilot plant from 1954 to 1958. The last shipment of uranium concentrate was sent from GJPO in January, 1975. Since that time the site has been utilized to support various DOE programs, such as the former National Uranium Resource Evaluation (NURE) Program, the Uranium Mill Tailings Remedial Action Project (UMTRAP), the Surplus Facilities Management Program (SFMP), and the Technical Measurements Center (TMC). All known contamination at GJPO is believed to be the result of the past uranium milling, analyses, and storage activities. Hazards associated with the wastes impounded at GJPO include surface and ground-water contamination and potential radon and gamma-radiation exposure. This report documents the results of the Baseline Environmental Audit conducted at Grand Junction Projects Office (GJPO) located in Grand Junction, Colorado. The Grand Junction Baseline Environmental Audit was conducted from May 28 to June 12, 1991, by the Office of Environmental Audit (EH-24). This Audit evaluated environmental programs and activities at GJPO, as well as GJPO activities at the State-Owned Temporary Repository. 4 figs., 12 tabs.

    7. Computer-assisted data acquisition on Josephson junctions

      SciTech Connect (OSTI)

      Pagano, S. ); Costabile, G.; Fedullo, V.

      1989-09-01

      An automatic digital data-acquisition system for the test and characterization of superconducting Josephson tunnel junctions is presented. The key feature is represented by the high degree of interaction of the measurement system with the device under test. This is accomplished by an iterated sequence of data acquisitions, automatic analysis, and subsequent modifications of the control signals in the device. In this way, the basic calibration and the value of the relevant quantities involved with the Josephson junction are automatically determined. A connection with a host computer makes possible more complex data analysis, while the full control of the experiment by a dedicated computer allows the operator to perform nonroutine procedures.

    8. Josephson tunnel junctions with chemically vapor deposited polycrystalline germanium barriers

      SciTech Connect (OSTI)

      Kroger, H.; Jillie, D.W.; Smith, L.N.; Phaneuf, L.E.; Potter, C.N.; Shaw, D.M.; Cukauskas, E.J.; Nisenoff, M.

      1984-03-01

      High quality Josephson tunnel junctions have been fabricated whose tunneling barrier is polycrystalline germanium chemically vapor deposited on a NbN base electrode and covered by a Nb counterelectrode. These junctions have excellent characteristics for device applications: values of V/sub m/ (the product of the critical current and the subgap resistance measured at 2 mV and 4.2 K) ranging between 35--48 mV, ideal threshold curves, a steep current rise at the gap voltage, and Josephson current densities from 100 to 1100 A/cm/sup 2/.

    9. Interaction of Josephson Junction and Distant Vortex in Narrow Thin-Film Superconducting Strips

      SciTech Connect (OSTI)

      Kogan, V. G.; Mints, R. G.

      2014-01-31

      The phase difference between the banks of an edge-type planar Josephson junction crossing the narrow thin-film strip depends on wether or not vortices are present in the junction banks. For a vortex close to the junction this effect has been seen by Golod, Rydh, and Krasnov [Phys. Rev. Lett. 104, 227003 (2010)], who showed that the vortex may turn the junction into ? type. It is shown here that even if the vortex is far away from the junction, it still changes the 0 junction to a ? junction when situated close to the strip edges. Within the approximation used, the effect is independent of the vortex-junction separation, a manifestation of the topology of the vortex phase which extends to macroscopic distances of superconducting coherence.

    10. Optimized Triple-Junction Solar Cells Using Inverted Metamorphic Approach (Presentation)

      SciTech Connect (OSTI)

      Geisz, J. F.

      2008-11-01

      Record efficiencies with triple-junction inverted metamorphic designs, modeling useful to optimize, and consider operating conditions before choosing design.

    11. EERE Success Story—Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell

      Broader source: Energy.gov [DOE]

      EERE supported the development of Solar Junction's concentrated photovoltaic technology that set a world record for conversion efficiency.

    12. DOE/Grand Junction Office Bluewater LTSP July 1997 Doc. No. S00012AA...

      Office of Legacy Management (LM)

      DOEGrand Junction Office Bluewater LTSP July 1997 Doc. No. S00012AA, Page iii Contents Page 1.0 Introduction ......

    13. Performance model assessment for multi-junction concentrating photovoltaic systems.

      SciTech Connect (OSTI)

      Riley, Daniel M.; McConnell, Robert.; Sahm, Aaron; Crawford, Clark; King, David L.; Cameron, Christopher P.; Foresi, James S.

      2010-03-01

      Four approaches to modeling multi-junction concentrating photovoltaic system performance are assessed by comparing modeled performance to measured performance. Measured weather, irradiance, and system performance data were collected on two systems over a one month period. Residual analysis is used to assess the models and to identify opportunities for model improvement.

    14. ALTERNATIVE MATERIALS FOR RAMP-EDGE SNS JUNCTIONS

      SciTech Connect (OSTI)

      Jia, Q.; Fan, Y.

      1999-06-01

      We report on the processing optimization and fabrication of ramp-edge high-temperature superconducting junctions by using alternative materials for both superconductor electrodes and normal-metal barrier. By using Ag-doped YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (Ag:YBCO) as electrodes and a cation-modified compound of (Pr{sub y}Gd{sub 0.6{minus}y})Ca{sub 0.4}Ba{sub 1.6}La{sub 0.4}Cu{sub 3}O{sub 7} (y = 0.4, 0.5, and 0.6) as a normal-metal barrier, high-temperature superconducting Josephson junctions have been fabricated in a ramp-edge superconductor/normal-metal/superconductor (SNS) configuration. By using Ag:YBCO as electrodes, we have found that the processing controllability /reproducibility and the stability of the SNS junctions are improved substantially. The junctions fabricated with these alternative materials show well-defined RSJ-like current vs voltage characteristics at liquid nitrogen temperature.

    15. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

      SciTech Connect (OSTI)

      Beach, R.; Burdick, A.

      2014-03-01

      This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance. IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations. These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

    16. August 2015 Groundwater Sampling at the Grand Junction, Colorado, Disposal Site

      Office of Legacy Management (LM)

      Sampling at the Grand Junction, Colorado, Disposal Site October 2015 LMS/GRJ/S00815 This page intentionally left blank U.S. Department of Energy DVP-August 2015, Grand Junction, Colorado October 2015 RIN 15077245 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Disposal Site, Sample Location Map ...................................................3 Data Assessment

    17. January 2016 Groundwater and Surface Water Sampling at the Grand Junction, Colorado, Processing Site

      Office of Legacy Management (LM)

      6 Groundwater and Surface Water Sampling at the Grand Junction, Colorado, Processing Site March 2016 LMS/GJT/S00116 This page intentionally left blank U.S. Department of Energy DVP-January 2016, Grand Junction, Colorado March 2016 RIN 15127576 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Processing Site, Sample Location Map

    18. The chaotic oscillations of a Josephson junction with external magnetic field

      SciTech Connect (OSTI)

      Ma, J.G.; Wolff, I.

      1996-05-01

      Using the Melnikov Method the oscillation of a single Josephson junction with external magnetic field and DC bias is analyzed. Under the external magnetic field the junction can operate in chaos even if there is no bias. The numerical results show that in dependence on some parameters the Josephson junction with external magnetic field will go from stable periodic states to chaotic states.

    19. Antireflection Coating Design for Series Interconnected Multi-Junction Solar Cells

      SciTech Connect (OSTI)

      AIKEN,DANIEL J.

      1999-11-29

      AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J{sub SC}) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices.

    20. 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.

    1. Millikelvin cooling by heavy-fermion-based tunnel junctions

      SciTech Connect (OSTI)

      Prest, Martin; Min, Gao; Whall, Terry

      2015-12-28

      This paper addresses a high-performance electron-tunneling cooler based on a novel heavy-fermion/insulator/superconductor junction for millikelvin cooling applications. We show that the cooling performance of an electronic tunneling refrigerator could be significantly improved using a heavy-fermion metal to replace the normal metal in a conventional normal metal/insulator/superconductor junction. The calculation, based on typical parameters, indicates that, for a bath temperature of 300 mK, the minimum cooling temperature of an electron tunneling refrigerator is reduced from around 170 mK to below 50 mK if a heavy-fermion metal is employed in place of the normal metal. The improved cooling is attributed to an enhancement in electron tunneling due to the existence of a resonant density of states at the Fermi level.

    2. Grain boundary and triple junction diffusion in nanocrystalline copper

      SciTech Connect (OSTI)

      Wegner, M. Leuthold, J.; Peterlechner, M.; Divinski, S. V.; Song, X.; Wilde, G.

      2014-09-07

      Grain boundary and triple junction diffusion in nanocrystalline Cu samples with grain sizes, ?d?, of ?35 and ?44?nm produced by spark plasma sintering were investigated by the radiotracer method using the {sup 63}Ni isotope. The measured diffusivities, D{sub eff}, are comparable with those determined previously for Ni grain boundary diffusion in well-annealed, high purity, coarse grained, polycrystalline copper, substantiating the absence of a grain size effect on the kinetic properties of grain boundaries in a nanocrystalline material at grain sizes d???35?nm. Simultaneously, the analysis predicts that if triple junction diffusion of Ni in Cu is enhanced with respect to the corresponding grain boundary diffusion rate, it is still less than 500?D{sub gb} within the temperature interval from 420?K to 470?K.

    3. Towards understanding junction degradation in cadmium telluride solar cells

      SciTech Connect (OSTI)

      Nardone, Marco

      2014-06-21

      A degradation mechanism in cadmium telluride (CdTe/CdS) solar cells is investigated using time-dependent numerical modeling to simulate various temperature, bias, and illumination stress conditions. The physical mechanism is based on defect generation rates that are proportional to nonequilibrium charge carrier concentrations. It is found that a commonly observed degradation mode for CdTe/CdS solar cells can be reproduced only if defects are allowed to form in a narrow region of the absorber layer close to the CdTe/CdS junction. A key aspect of this junction degradation is that both mid-gap donor and shallow acceptor-type defects must be generated simultaneously in response to photo-excitation or applied bias. The numerical approach employed here can be extended to study other mechanisms for any photovoltaic technology.

    4. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells

      SciTech Connect (OSTI)

      Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

      2011-01-01

      We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n{sup ++} Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

    5. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells: Preprint

      SciTech Connect (OSTI)

      Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

      2011-07-01

      We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n++ Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

    6. Fractional quantum Hall junctions and two-channel Kondo models

      SciTech Connect (OSTI)

      Sandler, Nancy P.; Fradkin, Eduardo

      2001-06-15

      A mapping between fractional quantum Hall (FQH) junctions and the two-channel Kondo model is presented. We discuss this relation in detail for the particular case of a junction of a FQH state at {nu}=1/3 and a normal metal. We show that in the strong coupling regime this junction has a non-Fermi-liquid fixed point. At this fixed point the electron Green{close_quote}s function has a branch cut and the impurity entropy is equal to S=1/2ln2. We construct the space of perturbations at the strong coupling fixed point and find that the dimension of the tunneling operator is 1/2. These properties are strongly reminiscent of the non-Fermi-liquid fixed points of a number of quantum impurity models, particularly the two-channel Kondo model. However we have found that, in spite of these similarities, the Hilbert spaces of these two systems are quite different. In particular, although in a special limit the Hamiltonians of both systems are the same, their Hilbert spaces are not since they are determined by physically distinct boundary conditions. As a consequence the spectrum of operators in the two problems is different.

    7. Environmental assessment of facility operations at the U.S. Department of Energy Grand Junction Projects Office, Grand Junction, Colorado

      SciTech Connect (OSTI)

      1996-06-01

      The US Department of Energy (DOE) has prepared a sitewide environmental assessment (EA) of the proposed action to continue and expand present-day activities on the DOE Grand Junction Projects Office (GJPO) facility in Grand Junction, Colorado. Because DOE-GJPO regularly proposes and conducts many different on-site activities, DOE decided to evaluate these activities in one sitewide EA rather than in multiple, activity-specific documents. On the basis of the information and analyses presented in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, as defined by the National Environmental Policy Act (NEPA) of 1969. Therefore, preparation of an environmental impact statement is not required for facility operations, and DOE is issuing this Finding of No Significant Impact (FONSI).

    8. Joint measurement of current-phase relations and transport properties of hybrid junctions using a three junctions superconducting quantum interference device

      SciTech Connect (OSTI)

      Basset, J.; Delagrange, R.; Weil, R.; Kasumov, A.; Bouchiat, H.; Deblock, R.

      2014-07-14

      We propose a scheme to measure both the current-phase relation and differential conductance dI/dV of a superconducting junction, in the normal and the superconducting states. This is done using a dc Superconducting Quantum Interference Device with two Josephson junctions in parallel with the device under investigation and three contacts. As a demonstration, we measure the current-phase relation and dI/dV of a small Josephson junction and a carbon nanotube junction. In this latter case, in a regime where the nanotube is well conducting, we show that the non-sinusoidal current phase relation we find is consistent with the theory for a weak link, using the transmission extracted from the differential conductance in the normal state. This method holds great promise for future investigations of the current-phase relation of more exotic junctions.

    9. A Model for the Behavior of Magnetic Tunnel Junctions

      SciTech Connect (OSTI)

      Bryan John Baker

      2003-08-05

      A magnetic tunnel junction is a device that changes its electrical resistance with a change in an applied magnetic field. A typical junction consists of two magnetic electrodes separated by a nonmagnetic insulating layer. The magnetizations of the two electrodes can have two possible extreme configurations, parallel and antiparallel. The antiparallel configuration is observed to have the higher measured resistance and the parallel configuration has the lower resistance. To switch between these two configurations a magnetic field is applied to the device which is primarily used to change the orientation of the magnetization of one electrode usually called the free layer, although with sufficient high magnetic field the orientation of the magnetizations of both of the electrodes can be changed. The most commonly used models for describing and explaining the electronic behavior of tunnel junctions are the Simmons model and the Brinkman model. However, both of these models were designed for simple, spin independent tunneling. The Simmons model does not address the issue of applied magnetic fields nor does it address the form of the electronic band structure in the metallic electrodes, including the important factor of spin polarization. The Brinkman model is similar, the main difference between the two models being the shape of the tunneling barrier potential between the two electrodes. Therefore, the research conducted in this thesis has developed a new theoretical model that addresses these important issues starting from basic principles. The main features of the new model include: the development of equations for true spin dependent tunneling through the insulating barrier, the differences in the orientations of the electrode magnetizations on either side of the barrier, and the effects of the density of states function on the behavior of the junction. The present work has explored densities of states that are more realistic than the simplified free electron density

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

      DOE Patents [OSTI]

      Toet, Daniel; Sigmon, Thomas W.

      2005-08-23

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

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

      DOE Patents [OSTI]

      Toet, Daniel; Sigmon, Thomas W.

      2003-01-01

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

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

      DOE Patents [OSTI]

      Toet, Daniel; Sigmon, Thomas W.

      2004-12-07

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

    13. Shunt-capacitor-assisted synchronization of oscillations in intrinsic Josephson junctions stack.

      SciTech Connect (OSTI)

      Martin, I.; Halasz, G. B.; Bulaevskii, L. N.; Koshelev, A. E.; Materials Science Division; LANL

      2010-08-06

      We show that a shunt capacitor, by coupling each Josephson junction to all the other junctions, stabilizes synchronized oscillations in an intrinsic Josephson junction stack biased by a dc current. This synchronization mechanism is similar to the previously discussed radiative coupling between junctions, however, it is not defined by the geometry of the stack. It is particularly important in crystals with smaller numbers of junctions (where the radiation coupling is weak), and is comparable with the effect of strong super-radiation in crystals with many junctions. The shunt also helps to enter the phase-locked regime in the beginning of the oscillations, after switching on the bias current. Furthermore, it may be used to tune radiation power, which drops as the shunt capacitance increases.

    14. Voltage dependence of the differential capacitance of a p{sup +}-n junction

      SciTech Connect (OSTI)

      Shekhovtsov, N. A.

      2013-04-15

      The dependences of the differential capacitance and current of a p{sup +}-n junction with a uniformly doped n region on the voltage in the junction region are calculated. The p{sup +}-n junction capacitance controls the charge change in the junction region taking into account a change in the electric field of the quasi-neutral n region and a change in its bipolar drift mobility with increasing excess charge-carrier concentration. It is shown that the change in the sign of the p{sup +}-n junction capacitance with increasing injection level is caused by a decrease in the bipolar drift mobility as the electron-hole pair concentration in the n region increases. It is shown that the p{sup +}-n junction capacitance decreases with increasing reverse voltage and tends to a constant positive value.

    15. Niobium nitride-niobium Josephson tunnel junctions with sputtered amorphous silicon barriers

      SciTech Connect (OSTI)

      Jillie, D.W.; Kroger, H.; Smith, L.N.; Cukauskas, E.J.; Nisenoff, M.

      1982-04-15

      Niobium nitride-niobium Josephson tunnel junctions with sputtered amorphous silicon barriers (NbN-..cap alpha..Si-Nb) have been prepared using processing that is fully compatible with integrated circuit fabrication. These junctions are of suitable quality and uniformity for digital circuit and S-I-S detector applications. The junction quality depends critically upon the properties of the NbN surface, and seems to correlate well with the UV/visible reflectivity of this surface.

    16. GaInNAs Junctions for Next-Generation Concentrators: Progress and Prospects

      SciTech Connect (OSTI)

      Friedman, D. J.; Ptak, A. J.; Kurtz, S. R.; Geisz, J. F.; Kiehl, J.

      2005-08-01

      We discuss progress in the development of GaInNAs junctions for application in next-generation multijunction concentrator cells. A significant development is the demonstration of near-100% internal quantum efficiencies in junctions grown by molecular-beam epitaxy. Testing at high currents validates the compatibility of these devices with concentrator operation. The efficiencies of several next-generation multijunction structures incorporating these state-of-the-art GaInNAs junctions are projected.

    17. Grand Junction, Colorado, Disposal Site Long-Term Surveillance and Maintenance Program Fact Sheet, July 2001

      Office of Legacy Management (LM)

      Grand Junction Disposal Site Uranium ore was processed at the Climax millsite at Grand Junction, Colorado, between 1951 and 1970. The milling operations created process-related waste and tailings, a sandlike material containing radioactive materials and other contaminants. The tailings were an ideal and inexpensive construction material suitable for concrete, mortar, and fill. Accordingly, the tailings were widely used in the Grand Junction area for these purposes. The U.S. Department of Energy

    18. Greenfield, New Hampshire: Energy Resources | Open Energy Information

      Open Energy Info (EERE)

      County, New Hampshire.1 References US Census Bureau Incorporated place and minor civil division population dataset (All States, all geography) Retrieved from "http:...

    19. Building America Case Study: Conway Street Apartments, Greenfield...

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

      Project Name: Conway Street Apartments: A Multifamily Deep ... America program is engineering the American home for ... LIGHTING, APPLIANCES, AND WATER HEATING * Solar thermal ...

    20. AmeriFlux US-Bn1 Bonanza Creek, 1920 Burn site near Delta Junction

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

      Randerson, James [University of California, Irvine

      2016-01-01

      This is the AmeriFlux version of the carbon flux data for the site US-Bn1 Bonanza Creek, 1920 Burn site near Delta Junction. Site Description - The Delta Junction 1920 Control site is located near Delta Junction, just to the north of the Alaska Range in interior Alaska. All three Delta Junction sites are within a 15-km radius of one another. Composed of a combination of alluvial outwashes, floodplains, and low terraces dissected by glacial streams originating in the nearby Alaska Range. In 2001, total aboveground biomass consisted almost entirely of black spruce (Picea mariana).

    1. NREL and CSEM Jointly Set New Efficiency Record with Dual-Junction...

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

      NREL and CSEM Jointly Set New Efficiency Record with Dual-Junction Solar Cell January 5, 2016 Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) and ...

    2. 2011 Annual Planning Summary for Office of Legacy Management (LM), Grand Junction (See LM APS)

      Broader source: Energy.gov [DOE]

      The ongoing and projected Environmental Assessments and Environmental Impact Statements for 2011 and 2012 within the Office of Legacy Management (LM), Grand Junction (See LM APS).

    3. Proper Orthogonal Decomposition of the Flow in a T-Junction ...

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

      T-Junction (In: Advances in Nuclear Power Plants) Authors: Merzari, E., Pointer, W.D., ... Congress on Advances in Nuclear Power Plants 2010 (ICAPP 2010) Publisher: Curran ...

    4. NREL and CSEM Jointly Set New Efficiency Record with Dual-Junction...

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

      NREL and CSEM Jointly Set New Efficiency Record with Dual-Junction Solar Cell January 5, 2016 Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) and...

    5. Enhancement of tunnel magnetoresistance in magnetic tunnel junction by a superlattice barrier

      SciTech Connect (OSTI)

      Chen, C. H.; Hsueh, W. J.

      2014-01-27

      Tunnel magnetoresistance of magnetic tunnel junction improved by a superlattice barrier composed of alternate layers of a nonmagnetic metal and an insulator is proposed. The forbidden band of the superlattice is used to predict the low transmission range in the superlattice barrier. By forbidding electron transport in the anti-parallel configuration, the tunnel magnetoresistance is enhanced in the superlattice junction. The results show that the tunnel magnetoresistance ratio for a superlattice magnetic tunnel junction is greater than that for traditional single or double barrier junctions.

    6. Engineering ferroelectric tunnel junctions through potential profile shaping

      SciTech Connect (OSTI)

      Boyn, S.; Garcia, V. Fusil, S.; Carrtro, C.; Garcia, K.; Collin, S.; Deranlot, C.; Bibes, M.; Barthlmy, A.

      2015-06-01

      We explore the influence of the top electrode materials (W, Co, Ni, Ir) on the electronic band profile in ferroelectric tunnel junctions based on super-tetragonal BiFeO{sub 3}. Large variations of the transport properties are observed at room temperature. In particular, the analysis of current vs. voltage curves by a direct tunneling model indicates that the metal/ferroelectric interfacial barrier height increases with the top-electrode work function. While larger metal work functions result in larger OFF/ON ratios, they also produce a large internal electric field which results in large and potentially destructive switching voltages.

    7. Inverted GaInP/(In)GaAs/InGaAs Triple-Junction Solar Cells with Low-Stress Metamorphic Bottom Junctions: Preprint

      SciTech Connect (OSTI)

      Geisz, J. F.; Kurtz, S. R.; Wanlass, M. W.; Ward, J. S.; Duda, A.; Friedman, D. J.; Olson, J. M.; McMahon, W. E.; Moriarty, T. E.; Kiehl, J. T.; Romero, M. J.; Norman, A. G.; Jones, K. M.

      2008-05-01

      We demonstrate high efficiency performance in two ultra-thin, Ge-free III-V semiconductor triple-junction solar cell device designs grown in an inverted configuration. Low-stress metamorphic junctions were engineered to achieve excellent photovoltaic performance with less than 3 x 106 cm-2 threading dislocations. The first design with band gaps of 1.83/1.40/1.00 eV, containing a single metamorphic junction, achieved 33.8% and 39.2% efficiencies under the standard one-sun global spectrum and concentrated direct spectrum at 131 suns, respectively. The second design with band gaps of 1.83/1.34/0.89 eV, containing two metamorphic junctions achieved 33.2% and 40.1% efficiencies under the standard one-sun global spectrum and concentrated direct spectrum at 143 suns, respectively.

    8. Low temperature junction growth using hot-wire chemical vapor deposition

      SciTech Connect (OSTI)

      Wang, Qi; Page, Matthew; Iwaniczko, Eugene; Wang, Tihu; Yan, Yanfa

      2014-02-04

      A system and a process for forming a semi-conductor device, and solar cells (10) formed thereby. The process includes preparing a substrate (12) for deposition of a junction layer (14); forming the junction layer (14) on the substrate (12) using hot wire chemical vapor deposition; and, finishing the semi-conductor device.

    9. December 2015 Groundwater and Surface Waater Sampling at the Grand Junction, Colorado, Site

      Office of Legacy Management (LM)

      and Surface Water Sampling at the Grand Junction, Colorado, Site March 2016 LMS/GJO/S01215 This page intentionally left blank U.S. Department of Energy DVP-December 2015, Grand Junction, Colorado March 2016 RIN 15117528 Page i Contents Sampling Event Summary ...............................................................................................................1 Data Assessment Summary

    10. Josephson tunnel junction with polycrystalline silicon, germanium or silicon-germanium alloy tunneling barrier

      SciTech Connect (OSTI)

      Kroger, H.

      1980-09-02

      A Josephson tunnel junction device having niobium nitride superconductive electrodes includes a polycrystalline semiconductor tunnelling barrier therebetween comprised of silicon, germanium or an alloy thereof preferably deposited on the lower superconductive electrodes by chemical vapor deposition. The barrier height of the junction is precisely controlled by precision doping of the semiconductor material.

    11. Imaging the p-n junction in a gallium nitride nanowire with a scanning microwave microscope

      SciTech Connect (OSTI)

      Imtiaz, Atif; Wallis, Thomas M.; Brubaker, Matt D.; Blanchard, Paul T.; Bertness, Kris A.; Sanford, Norman A.; Kabos, Pavel; Weber, Joel C.; Coakley, Kevin J.

      2014-06-30

      We used a broadband, atomic-force-microscope-based, scanning microwave microscope (SMM) to probe the axial dependence of the charge depletion in a p-n junction within a gallium nitride nanowire (NW). SMM enables the visualization of the p-n junction location without the need to make patterned electrical contacts to the NW. Spatially resolved measurements of S{sub 11}{sup ?}, which is the derivative of the RF reflection coefficient S{sub 11} with respect to voltage, varied strongly when probing axially along the NW and across the p-n junction. The axial variation in S{sub 11}{sup ?}? effectively mapped the asymmetric depletion arising from the doping concentrations on either side of the junction. Furthermore, variation of the probe tip voltage altered the apparent extent of features associated with the p-n junction in S{sub 11}{sup ?} images.

    12. Dislocation Dynamics Simulations of Junctions in Hexagonal Close-Packed Crystals

      SciTech Connect (OSTI)

      Wu, C; Aubry, S; Chung, P; Arsenlis, A

      2011-12-05

      The formation and strength of dislocations in the hexagonal closed packed material beryllium are studied through dislocation junctions and the critical stress required to break them. Dislocation dynamics calculations (using the code ParaDiS) of junction maps are compared to an analytical line tension approximation in order to validate our model. Results show that the two models agree very well. Also the critical shear stress necessary to break 30{sup o} - 30{sup o} and 30{sup o} - 90{sup o} dislocation junctions is computed numerically. Yield surfaces are mapped out for these junctions to describe their stability regions as function of resolved shear stresses on the glide planes. The example of two non-coplanar binary dislocation junctions with slip planes [2-1-10] (01-10) and [-12-10] (0001) corresponding to a prismatic and basal slip respectively is chosen to verify and validate our implementation.

    13. Laboratory instrumentation and techniques for characterizing multi-junction solar cells for space applications

      SciTech Connect (OSTI)

      Woodyard, J.R.

      1995-10-01

      Multi-junction solar cells are attractive for space applications because they can be designed to convert a larger fraction of AMO into electrical power at a lower cost than single-junction cells. The performance of multi-junction cells is much more sensitive to the spectral irradiance of the illuminating source than single-junction cells. The design of high efficiency multi-junction cells for space applications requires matching the optoelectronic properties of the junctions to AMO spectral irradiance. Unlike single-junction cells, it is not possible to carry out quantum efficiency measurements using only a monochromatic probe beam and determining the cell short-circuit current assuming linearity of the quantum efficiency. Additionally, current-voltage characteristics can not be calculated from measurements under non-AMO light sources using spectral-correction methods. There are reports in the literature on characterizing the performance of multi junction cells by measuring and convoluting the quantum efficiency of each junction with the spectral irradiance; the technique is of limited value for the characterization of cell performance under AMO power-generating conditions. The authors report the results of research to develop instrumentation and techniques for characterizing multi junction solar cells for space . An integrated system is described which consists of a standard lamp, spectral radiometer, dual-source solar simulator, and personal computer based current-voltage and quantum efficiency equipment. The spectral radiometer is calibrated regularly using the tungsten-halogen standard lamp which has a calibration based on NIST scales. The solar simulator produces the light bias beam for current-voltage and cell quantum efficiency measurements. The calibrated spectral radiometer is used to `fit` the spectral irradiance of the dual-source solar simulator to WRL AMO data.

    14. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

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

      Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

      2014-12-17

      In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Dopplermore » Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.« less

    15. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

      SciTech Connect (OSTI)

      Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

      2014-12-17

      In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.

    16. Ischemic preconditioning enhances integrity of coronary endothelial tight junctions

      SciTech Connect (OSTI)

      Li, Zhao; Jin, Zhu-Qiu

      2012-08-31

      Highlights: Black-Right-Pointing-Pointer Cardiac tight junctions are present between coronary endothelial cells. Black-Right-Pointing-Pointer Ischemic preconditioning preserves the structural and functional integrity of tight junctions. Black-Right-Pointing-Pointer Myocardial edema is prevented in hearts subjected to ischemic preconditioning. Black-Right-Pointing-Pointer Ischemic preconditioning enhances translocation of ZO-2 from cytosol to cytoskeleton. -- Abstract: Ischemic preconditioning (IPC) is one of the most effective procedures known to protect hearts against ischemia/reperfusion (IR) injury. Tight junction (TJ) barriers occur between coronary endothelial cells. TJs provide barrier function to maintain the homeostasis of the inner environment of tissues. However, the effect of IPC on the structure and function of cardiac TJs remains unknown. We tested the hypothesis that myocardial IR injury ruptures the structure of TJs and impairs endothelial permeability whereas IPC preserves the structural and functional integrity of TJs in the blood-heart barrier. Langendorff hearts from C57BL/6J mice were prepared and perfused with Krebs-Henseleit buffer. Cardiac function, creatine kinase release, and myocardial edema were measured. Cardiac TJ function was evaluated by measuring Evans blue-conjugated albumin (EBA) content in the extravascular compartment of hearts. Expression and translocation of zonula occludens (ZO)-2 in IR and IPC hearts were detected with Western blot. A subset of hearts was processed for the observation of ultra-structure of cardiac TJs with transmission electron microscopy. There were clear TJs between coronary endothelial cells of mouse hearts. IR caused the collapse of TJs whereas IPC sustained the structure of TJs. IR increased extravascular EBA content in the heart and myocardial edema but decreased the expression of ZO-2 in the cytoskeleton. IPC maintained the structure of TJs. Cardiac EBA content and edema were reduced in IPC hearts. IPC

    17. Cooperative Research between NREL and Solar Junction Corp: Cooperative Research and Development Final Report, CRADA Number CRD-08-306

      SciTech Connect (OSTI)

      Friedman, D.

      2015-03-01

      NREL and Solar Junction Corp. will perform cooperative research on materials and devices that are alternatives to standard approaches with the goal of improving solar cell efficiency while lowering cost. The general purpose of this work is to model the performance of a multi-junction concentrator cell of Solar Junction, Inc. design under normal concentrator operating conditions.

    18. Performance model assessment for multi-junction concentrating photovoltaic systems.

      SciTech Connect (OSTI)

      Stein, Joshua S.; Riley, Daniel M.; McConnell, Robert.; Sahm, Aaron; Crawford, Clark; King, David L.; Cameron, Christopher P.; Foresi, James S.

      2010-03-01

      Four approaches to modeling multi-junction concentrating photovoltaic system performance are assessed by comparing modeled performance to measured performance. Measured weather, irradiance, and system performance data were collected on two systems over a one month period. Residual analysis is used to assess the models and to identify opportunities for model improvement. Large photovoltaic systems are typically developed as projects which supply electricity to a utility and are owned by independent power producers. Obtaining financing at favorable rates and attracting investors requires confidence in the projected energy yield from the plant. In this paper, various performance models for projecting annual energy yield from Concentrating Photovoltaic (CPV) systems are assessed by comparing measured system output to model predictions based on measured weather and irradiance data. The results are statistically analyzed to identify systematic error sources.

    19. Chemical Fabrication of Heterometallic Nanogaps for Molecular Transport Junctions

      SciTech Connect (OSTI)

      Chen, Xiaodong; Yeganeh, Sina; Qin, Lidong; Li, Shuzhou; Xue, Can; Braunschweig, Adam B.; Schatz, George C.; Ratner, Mark A.; Mirkin, Chad A.

      2009-01-01

      We report a simple and reproducible method for fabricating heterometallic nanogaps, which are made of two different metal nanorods separated by a nanometer-sized gap. The method is based upon on-wire lithography, which is a chemically enabled technique used to synthesize a wide variety of nanowire-based structures (e.g., nanogaps and disk arrays). This method can be used to fabricate pairs of metallic electrodes, which exhibit distinct work functions and are separated by gaps as small as 2 nm. Furthermore, we demonstrate that a symmetric thiol-terminated molecule can be assembled into such heterometallic nanogaps to form molecular transport junctions (MTJs) that exhibit molecular diode behavior. Theoretical calculations demonstrate that the coupling strength between gold and sulfur (Au-S) is 2.5 times stronger than that of Pt-S. In addition, the structures form Raman hot spots in the gap, allowing the spectroscopic characterization of the molecules that make up the MTJs.

    20. Fluxons in a triangular set of coupled long Josephson junctions

      SciTech Connect (OSTI)

      Yukon, Stanford P.; Malomed, Boris A.

      2015-09-15

      We report results of an analysis of the dynamics of magnetic flux solitons in the system of three long Josephson junctions between three bulk superconductors that form a prism. The system is modeled by coupled sine-Gordon equations for the phases of the junctions. The Aharonov-Bohm constraint takes into account the axial magnetic flux enclosed by the prism and reduces the system from three independent phases to two. The equations of motion for the phases include dissipative terms, and a control parameter δ which accounts for the deviation of the enclosed flux from half a quantum. Analyzing the effective potential of the coupled equations, we identify different species of topological and non-topological phase solitons (fluxons) in this system. In particular, subkinks with fractional topological charges ±1/3 and ±2/3, confined inside integer-charge fluxons, may be mapped onto the root diagrams for mesons and baryons in the original quark model of hadrons. Solutions for straight-line kinks and for two types of non-topological solitons are obtained in an explicit analytical form. Numerical tests demonstrate that the former species is unstable against breakup into pairs of separating single-fluxon kinks. The non-topological kinks feature metastability, eventually breaking up into fluxon-antifluxon pairs. Free fractional-fluxon kinks, that connect different potential minima and are, accordingly, pulled by the potential difference, are also considered. Using the momentum-balance method, we predict the velocity at which these kinks should move in the presence of the dissipation. Numerical tests demonstrate that the analysis predicts the velocity quite closely. Higher-energy static solutions for all of the stable kink types mentioned above, as well as kinks connecting false vacua, are found by means of the shooting method. Inelastic collisions among the stable fractional and single-fluxon kinks are investigated numerically.

    1. Realistic-contact-induced enhancement of rectifying in carbon-nanotube/graphene-nanoribbon junctions

      SciTech Connect (OSTI)

      Zhang, Xiang-Hua [School of Physics and Microelectronics Science, Hunan University, Changsha 410082 (China); Department of Electrical and Information Engineering, Hunan Institute of Engineering, Xiangtan 411101 (China); Li, Xiao-Fei, E-mail: xfli@theochem.kth.se [School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Wang, Ling-Ling, E-mail: llwang@hnu.edu.cn; Xu, Liang; Luo, Kai-Wu [School of Physics and Microelectronics Science, Hunan University, Changsha 410082 (China)

      2014-03-10

      Carbon-nanotube/graphene-nanoribbon junctions were recently fabricated by the controllable etching of single-walled carbon-nanotubes [Wei et al., Nat. Commun. 4, 1374 (2013)] and their electronic transport properties were studied here. First principles results reveal that the transmission function of the junctions show a heavy dependence on the shape of contacts, but rectifying is an inherent property which is insensitive to the details of contacts. Interestingly, the rectifying ratio is largely enhanced in the junction with a realistic contact and the enhancement is insensitive to the details of contact structures. The stability of rectifying suggests a significant feasibility to manufacture realistic all-carbon rectifiers in nanoelectronics.

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

      DOE Patents [OSTI]

      Madan, A.

      1984-12-10

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

    3. Performance of single-junction and dual-junction InGaP/GaAs solar cells under low concentration ratios

      SciTech Connect (OSTI)

      Khan, Aurangzeb; Yamaguchi, Masafumi; Takamoto, Tatsuya

      2004-10-11

      A study of the performance of single-junction InGaP/GaAs and dual-junction InGaP/GaAs tandem cells under low concentration ratios (up to 15 suns), before and after 1 MeV electron irradiation is presented. Analysis of the tunnel junction parameters under different concentrated light illuminations reveals that the peak current (J{sub P}) and valley current (J{sub V}) densities should be greater than the short-circuit current density (J{sub sc}) for better performance. The tunnel junction behavior against light intensity improved after irradiation. This led to the suggestion that the peak current density (J{sub P}) and valley current density (J{sub V}) of the tunnel junction were enhanced after irradiation or the peak current was shifted to higher concentration. The recovery of the radiation damage under concentrated light illumination conditions suggests that the performance of the InGaP/GaAs tandem solar cell can be enhanced even under low concentration ratios.

    4. Device characterization for design optimization of 4 junction inverted metamorphic concentrator solar cells

      SciTech Connect (OSTI)

      Geisz, John F.; France, Ryan M.; Steiner, Myles A.; Friedman, Daniel J.; Garca, Ivn

      2014-09-26

      Quantitative electroluminescence (EL) and luminescent coupling (LC) analysis, along with more conventional characterization techniques, are combined to completely characterize the subcell JV curves within a fourjunction (4J) inverted metamorphic solar cell (IMM). The 4J performance under arbitrary spectral conditions can be predicted from these subcell JV curves. The internal radiative efficiency (IRE) of each junction has been determined as a function of current density from the external radiative efficiency using optical modeling, but this required the accurate determination of the individual junction current densities during the EL measurement as affected by LC. These measurement and analysis techniques can be applied to any multijunction solar cell. The 4J IMM solar cell used to illustrate these techniques showed excellent junction quality as exhibited by high IRE and a one-sun AM1.5D efficiency of 36.3%. This device operates up to 1000 suns without limitations due to any of the three tunnel junctions.

    5. Materials en Multi-junction Solar Cells to Push CPV Efficiencies...

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

      ceem.ucsb.edurss News and Events - Center for Energy Efficient Materials en Multi-junction Solar Cells to Push CPV Efficiencies Beyond 50% http:www.compoundsemiconductor.net...

    6. Highly efficient organic multi-junction solar cells with a thiophene based donor material

      SciTech Connect (OSTI)

      Meerheim, Rico Krner, Christian; Leo, Karl

      2014-08-11

      The efficiency of organic solar cells can be increased by serial stacked subcells even upon using the same absorber material. For the multi-junction devices presented here, we use the small molecule donor material DCV5T-Me. The subcell currents were matched by optical transfer matrix simulation, allowing an efficiency increase from 8.3% for a single junction up to 9.7% for a triple junction cell. The external quantum efficiency of the subcells, measured under appropriate light bias illumination, is spectrally shifted due to the microcavity of the complete stack, resulting in a broadband response and an increased cell current. The increase of the power conversion efficiency upon device stacking is even stronger for large area cells due to higher influence of the resistance of the indium tin oxide anode, emphasizing the advantage of multi-junction devices for large-area applications.

    7. AmeriFlux US-Bn2 Bonanza Creek, 1987 Burn site near Delta Junction

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

      Randerson, James [University of California, Irvine

      2016-01-01

      This is the AmeriFlux version of the carbon flux data for the site US-Bn2 Bonanza Creek, 1987 Burn site near Delta Junction. Site Description - The Delta Junction 1987 Burn site is located near Delta Junction, just to the north of the Alaska Range in interior Alaska. All three Delta Junction sites are within a 15-km radius of one another. Composed of a combination of alluvial outwashes, floodplains, and low terraces dissected by glacial streams originating in the nearby Alaska Range. The Granite Creek fire burned ~20,000 ha of black spruce (Picea mariana) during 1987. Approximately half of the dead boles remained upright in 2004, while the other half had fallen over or had become entangled with other boles.

    8. AmeriFlux US-Bn3 Bonanza Creek, 1999 Burn site near Delta Junction

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

      Randerson, James [University of California, Irvine

      2016-01-01

      This is the AmeriFlux version of the carbon flux data for the site US-Bn3 Bonanza Creek, 1999 Burn site near Delta Junction. Site Description - The Delta Junction 1999 Burn site is located near Delta Junction, just to the north of the Alaska Range in interior Alaska. All three Delta Junction sites are within a 15-km radius of one another. Composed of a combination of alluvial outwashes, floodplains, and low terraces dissected by glacial streams originating in the nearby Alaska Range. The Donnelly Flats fire burned ~7,600 ha of black spruce (Picea mariana) during June 1999. The boles of the black spruce remained standing 3 years after the fire. 70% of the surface was not covered by vascular plants.

    9. Low-bias negative differential resistance effect in armchair graphene nanoribbon junctions

      SciTech Connect (OSTI)

      Li, Suchun; Gan, Chee Kwan; Son, Young-Woo; Feng, Yuan Ping; Quek, Su Ying

      2015-01-05

      Graphene nanoribbons with armchair edges (AGNRs) have bandgaps that can be flexibly tuned via the ribbon width. A junction made of a narrower AGNR sandwiched between two wider AGNR leads was recently reported to possess two perfect transmission channels close to the Fermi level. Here, we report that by using a bias voltage to drive these transmission channels into the gap of the wider AGNR lead, we can obtain a negative differential resistance (NDR) effect. Owing to the intrinsic properties of the AGNR junctions, the on-set bias reaches as low as ∼0.2 V and the valley current almost vanishes. We further show that such NDR effect is robust against details of the atomic structure of the junction, substrate, and whether the junction is made by etching or by hydrogenation.

    10. Updated Radiation Exhibit Unveiled at Math and Science Center in Grand Junction, Colorado

      Broader source: Energy.gov [DOE]

      A newly updated radiation exhibit, created by the U.S. Department of Energy (DOE) Office of Legacy Management (LM) office in Grand Junction, Colorado, was recently unveiled at the John McConnell...

    11. Method And Apparatus For Reducing Sample Dispersion In Turns And Junctions Of Micro-Channel Systems

      DOE Patents [OSTI]

      Griffiths, Stewart K. , Nilson, Robert H.

      2004-05-11

      What is disclosed pertains to improvement in the performance of microchannel devices by providing turns, wyes, tees, and other junctions that produce little dispersion of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. The low dispersion features are particularly suited for microfluidic devices and systems using either electromotive force, pressure, or combinations thereof as the principle of fluid transport. Such microfluidic devices and systems are useful for separation of components, sample transport, reaction, mixing, dilution or synthesis, or combinations thereof.

    12. Technology Solutions Case Study: New Insights for Improving the Designs of Flexible Duct Junction Boxes

      SciTech Connect (OSTI)

      2014-01-01

      In this project, IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance.

    13. A Manufacturing Cost Analysis Relevant to Single- and Dual-Junction...

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

      A Manufacturing Cost Analysis Relevant to Single- and Dual-Junction Photovoltaic Cells Fabricated with III-Vs and III-Vs Grown on Silicon A Manufacturing Cost Analysis Relevant to ...

    14. Preservationists Tour Historic Log Cabin at the Grand Junction, Colorado, Office

      Office of Energy Efficiency and Renewable Energy (EERE)

      A working committee of local historic preservation specialists held their monthly meeting at the U.S. Department of Energy Office of Legacy Management (LM) Grand Junction, Colorado, Office on...

    15. Grand Junction Office Founder Honored at the Philip C. Leahy Memorial Park Dedication and Open House

      Broader source: Energy.gov [DOE]

      The U.S. Department of Energy (DOE) Office of Legacy Management (LM) held an open house and park dedication at the Grand Junction, Colorado, Office to commemorate its place in the Manhattan Project...

    16. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

      DOE Patents [OSTI]

      Wanlass, Mark W.

      1994-01-01

      A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

    17. 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.

    18. Quantum interference in thermoelectric molecular junctions: A toy model perspective

      SciTech Connect (OSTI)

      Nozaki, Daijiro E-mail: research@nano.tu-dresden.de; Avdoshenko, Stas M.; Sevinçli, Hâldun; Cuniberti, Gianaurelio

      2014-08-21

      Quantum interference (QI) phenomena between electronic states in molecular circuits offer a new opportunity to design new types of molecular devices such as molecular sensors, interferometers, and thermoelectric devices. Controlling the QI effect is a key challenge for such applications. For the development of single molecular devices employing QI effects, a systematic study of the relationship between electronic structure and the quantum interference is needed. In order to uncover the essential topological requirements for the appearance of QI effects and the relationship between the QI-affected line shape of the transmission spectra and the electronic structures, we consider a homogeneous toy model where all on-site energies are identical and model four types of molecular junctions due to their topological connectivities. We systematically analyze their transmission spectra, density of states, and thermoelectric properties. Even without the degree of freedom for on-site energies an asymmetric Fano peak could be realized in the homogeneous systems with the cyclic configuration. We also calculate the thermoelectric properties of the model systems with and without fluctuation of on-site energies. Even under the fluctuation of the on-site energies, the finite thermoelectrics are preserved for the Fano resonance, thus cyclic configuration is promising for thermoelectric applications. This result also suggests the possibility to detect the cyclic configuration in the homogeneous systems and the presence of the QI features from thermoelectric measurements.

    19. Electron transport in molecular junctions with graphene as protecting layer

      SciTech Connect (OSTI)

      Hüser, Falco; Solomon, Gemma C.

      2015-12-07

      We present ab initio transport calculations for molecular junctions that include graphene as a protecting layer between a single molecule and gold electrodes. This vertical setup has recently gained significant interest in experiment for the design of particularly stable and reproducible devices. We observe that the signals from the molecule in the electronic transmission are overlayed by the signatures of the graphene sheet, thus raising the need for a reinterpretation of the transmission. On the other hand, we see that our results are stable with respect to various defects in the graphene. For weakly physiosorbed molecules, no signs of interaction with the graphene are evident, so the transport properties are determined by offresonant tunnelling between the gold leads across an extended structure that includes the molecule itself and the additional graphene layer. Compared with pure gold electrodes, calculated conductances are about one order of magnitude lower due to the increased tunnelling distance. Relative differences upon changing the end group and the length of the molecule on the other hand, are similar.

    20. Computational Fluid Dynamics Analysis of Flexible Duct Junction Box Design

      SciTech Connect (OSTI)

      Beach, Robert; Prahl, Duncan; Lange, Rich

      2013-12-01

      IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics (CFD) simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance. Current Air Conditioning Contractors of America (ACCA) guidance (Group 11, Appendix 3, ACCA Manual D, Rutkowski 2009) allows for unconstrained variation in the number of takeoffs, box sizes, and takeoff locations. The only variables currently used in selecting an equivalent length (EL) are velocity of air in the duct and friction rate, given the first takeoff is located at least twice its diameter away from the inlet. This condition does not account for other factors impacting pressure loss across these types of fittings. For each simulation, the IBACOS team converted pressure loss within a box to an EL to compare variation in ACCA Manual D guidance to the simulated variation. IBACOS chose cases to represent flows reasonably correlating to flows typically encountered in the field and analyzed differences in total pressure due to increases in number and location of takeoffs, box dimensions, and velocity of air, and whether an entrance fitting is included. The team also calculated additional balancing losses for all cases due to discrepancies between intended outlet flows and natural flow splits created by the fitting. In certain asymmetrical cases, the balancing losses were significantly higher than symmetrical cases where the natural splits were close to the targets. Thus, IBACOS has shown additional design constraints that can ensure better system performance.

    1. Electron transfer statistics and thermal fluctuations in molecular junctions

      SciTech Connect (OSTI)

      Goswami, Himangshu Prabal; Harbola, Upendra

      2015-02-28

      We derive analytical expressions for probability distribution function (PDF) for electron transport in a simple model of quantum junction in presence of thermal fluctuations. Our approach is based on the large deviation theory combined with the generating function method. For large number of electrons transferred, the PDF is found to decay exponentially in the tails with different rates due to applied bias. This asymmetry in the PDF is related to the fluctuation theorem. Statistics of fluctuations are analyzed in terms of the Fano factor. Thermal fluctuations play a quantitative role in determining the statistics of electron transfer; they tend to suppress the average current while enhancing the fluctuations in particle transfer. This gives rise to both bunching and antibunching phenomena as determined by the Fano factor. The thermal fluctuations and shot noise compete with each other and determine the net (effective) statistics of particle transfer. Exact analytical expression is obtained for delay time distribution. The optimal values of the delay time between successive electron transfers can be lowered below the corresponding shot noise values by tuning the thermal effects.

    2. Hydrogenated amorphous silicon barriers for niobium-niobium Josephson junctions

      SciTech Connect (OSTI)

      Kroger, H.; Aucoin, R.; Currier, L.W.; Jillie, D.W.; Potter, C.N.; Shaw, D.W.; Smith, L.N.; Thaxter, J.B.; Willis, P.H.

      1985-03-01

      The authors report on further studies of the effects of hydrogenation of sputtered amorphous silicon barriers upon the current-voltage (I-V) characteristics of Nb-Nb Josephson tunnel junctions. For composite trilayer barriers (a-Si/a-Si:H/a-Si) which are deposited using 8 mT of Ar, we find that there is an abrupt improvement in device characteristics when the central hydrogenated layer is deposited using a hydrogen partial pressure which exceeds about 0.5 mT. They attribute this to the reduction in the density of localized states in the a-Si:H layer. We have observed excellent I-V characteristics with trilayer barrier devices whose central hydrogenated layer is only about 1/7 of the thickness of the entire barrier. This observation suggests that localized states near the geometric center of the barrier are the most significant in degrading device characteristics. Annealing experiments and published data on the diffusion of deuterium in a-Si suggest that the composite barriers will be extremely stable during processing and storage. Zero bias anomalies in device I-V characteristics and spin density in the a-Si and a-Si:H layers have been measured.

    3. Spin Josephson effect in topological superconductor-ferromagnet junction

      SciTech Connect (OSTI)

      Ren, C. D.; Wang, J.

      2014-03-21

      The composite topological superconductor (TS), made of one-dimensional spin-orbit coupled nanowire with proximity-induced s-wave superconductivity, is not a pure p-wave superconductor but still has a suppressed s-wave pairing. We propose to probe the spin texture of the p-wave pairing in this composite TS by examining possible spin supercurrents in an unbiased TS/ferromagnet junction. It is found that both the exchange-coupling induced and spin-flip reflection induced spin currents exist in the setup and survive even in the topological phase. We showed that besides the nontrivial p-wave pairing state accounting for Majorana Fermions, there shall be a trivial p-wave pairing state that contributes to spin supercurrent. The trivial p-wave pairing state is diagnosed from the mixing effect between the suppressed s-wave pairing and the topologically nontrivial p-wave pairing. The d vector of the TS is proved not to be rigorously perpendicular to the spin projection of p-wave pairings. Our findings are also confirmed by the Kitaev's p-wave model with a nonzero s-wave pairing.

    4. High temperature superconductor step-edge Josephson junctions using Ti-Ca-Ba-Cu-O

      DOE Patents [OSTI]

      Ginley, D.S.; Hietala, V.M.; Hohenwarter, G.K.G.; Martens, J.S.; Plut, T.A.; Tigges, C.P.; Vawter, G.A.; Zipperian, T.E.

      1994-10-25

      A process is disclosed for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO[sub 3] crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O[sub 3], followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry. 8 figs.

    5. High temperature superconductor step-edge Josephson junctions using Ti-Ca-Ba-Cu-O

      DOE Patents [OSTI]

      Ginley, David S.; Hietala, Vincent M.; Hohenwarter, Gert K. G.; Martens, Jon S.; Plut, Thomas A.; Tigges, Chris P.; Vawter, Gregory A.; Zipperian, Thomas E.

      1994-10-25

      A process for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO.sub.3 crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O.sub.3, followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry.

    6. Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems

      DOE Patents [OSTI]

      Griffiths, Stewart K.; Nilson, Robert H.

      2001-01-01

      The performance of microchannel devices is improved by providing turns, wyes, tees, and other junctions that produce little dispersions of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. A numerical algorithm was employed to evolve low-dispersion geometries by computing the electric or pressure field within candidate configurations, sample transport through the turn or junction, and the overall effective dispersion. These devices should greatly increase flexibility in the design of microchannel devices by permitting the use of turns and junctions that do not induce large sample dispersion. In particular, the ability to fold electrophoretic and electrochrornatographic separation columns will allow dramatic improvements in the miniaturization of these devices. The low-lispersion devices are particularly suited to electrochromatographic and electrophoretic separations, as well as pressure-driven chromatographic separation. They are further applicable to microfluidic systems employing either electroosrnotic or pressure-driven flows for sample transport, reaction, mixing, dilution or synthesis.

    7. Structure–property relationships in atomic-scale junctions: Histograms and beyond

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

      Mark S. Hybertsen; Venkataraman, Latha

      2016-03-03

      Over the past 10 years, there has been tremendous progress in the measurement, modeling and understanding of structure–function relationships in single molecule junctions. Numerous research groups have addressed significant scientific questions, directed both to conductance phenomena at the single molecule level and to the fundamental chemistry that controls junction functionality. Many different functionalities have been demonstrated, including single-molecule diodes, optically and mechanically activated switches, and, significantly, physical phenomena with no classical analogues, such as those based on quantum interference effects. Experimental techniques for reliable and reproducible single molecule junction formation and characterization have led to this progress. In particular, themore » scanning tunneling microscope based break-junction (STM-BJ) technique has enabled rapid, sequential measurement of large numbers of nanoscale junctions allowing a statistical analysis to readily distinguish reproducible characteristics. Furthermore, harnessing fundamental link chemistry has provided the necessary chemical control over junction formation, enabling measurements that revealed clear relationships between molecular structure and conductance characteristics.« less

    8. Calculation of axial charge spreading in carbon nanotubes and nanotube Y junctions during STM measurement

      SciTech Connect (OSTI)

      Mark, Geza I.; Biro, Laszlo P.; Lambin, Philippe

      2004-09-15

      Distribution of the probability current and the probability density of wave packets was calculated for nanotubes and nanotube Y junctions by solving the three dimensional time-dependent Schroedinger equation for a jellium potential model of the scanning tunneling microscope (STM) tip-nanotube-support system. Four systems were investigated: an infinite single wall nanotube (SWNT) as reference case, a capped SWNT protruding a step of the support surface, a quantum dot (finite tube without support), and a SWNT Y junction. It is found that the spatial distribution of the probability current flowing into the sample is decided by the electron probability density of the tube and by the oscillation in time of the probability current, which in turn is governed by the quasibound states on the tube. For the infinite tube the width of the axial spreading of the wave packet during tunneling is about 5 nm. When the STM tip is above that part of the tube which protrudes from the atomic scale step of the support surface it is found that the current flows ballistically along the tube and the total transmission is the same as for the infinite tube. In the case of quantum dot, however, the finite tube is first charged in a short time then it is discharged very slowly through the tip-nanotube tunnel junction. In the Y junction both the above the junction and off the junction tip positions were investigated. For a 1.2 nm displacement of the tip from the junction the wave packet still 'samples' the junction point which means that in STM and scanning tunneling spectroscopy experiments the signature of the junction should be still present for such tip displacement. For all tunneling situations analyzed the tunnel current is mainly determined by the tip-nanotube junction owing to its large resistance. The tunneling event through the STM model is characterized by two time scales, the nanotube is quickly 'charged' with the wave packet coming from the tip then this 'charge' flows into the

    9. Environmental monitoring report on the US Department of Energy's Grand Junction Projects Office facility, Grand Junction, Colorado, for calendar year 1987

      SciTech Connect (OSTI)

      Not Available

      1988-05-01

      This report presents results of environmental monitoring activities conducted in 1987 at the US Department of Energy's (DOE) Grand Junction Projects Office (GJPO) Facility in Colorado. The site is included under the DOE's Defense Decontamination and Decommissioning (Defense D and D) Program.

    10. Detection of alpha particles using DNA/Al Schottky junctions

      SciTech Connect (OSTI)

      Al-Ta'ii, Hassan Maktuff Jaber E-mail: vengadeshp@um.edu.my; Periasamy, Vengadesh E-mail: vengadeshp@um.edu.my; Amin, Yusoff Mohd

      2015-09-21

      Deoxyribonucleic acid or DNA can be utilized in an organic-metallic rectifying structure to detect radiation, especially alpha particles. This has become much more important in recent years due to crucial environmental detection needs in both peace and war. In this work, we fabricated an aluminum (Al)/DNA/Al structure and generated current–voltage characteristics upon exposure to alpha radiation. Two models were utilized to investigate these current profiles; the standard conventional thermionic emission model and Cheung and Cheung's method. Using these models, the barrier height, Richardson constant, ideality factor and series resistance of the metal-DNA-metal structure were analyzed in real time. The barrier height, Φ value calculated using the conventional method for non-radiated structure was 0.7149 eV, increasing to 0.7367 eV after 4 min of radiation. Barrier height values were observed to increase after 20, 30 and 40 min of radiation, except for 6, 8, and 10 min, which registered a decrease of about 0.67 eV. This was in comparison using Cheung and Cheung's method, which registered 0.6983 eV and 0.7528 eV for the non-radiated and 2 min of radiation, respectively. The barrier height values, meanwhile, were observed to decrease after 4 (0.61 eV) to 40 min (0.6945 eV). The study shows that conventional thermionic emission model could be practically utilized for estimating the diode parameters including the effect of series resistance. These changes in the electronic properties of the Al/DNA/Al junctions could therefore be utilized in the manufacture of sensitive alpha particle sensors.

    11. Analysis of a four lamp flash system for calibrating multi-junction solar cells under concentrated light

      SciTech Connect (OSTI)

      Schachtner, Michael Prado, Marcelo Loyo; Reichmuth, S. Kasimir; Siefer, Gerald; Bett, Andreas W.

      2015-09-28

      It has been known for a long time that the precise characterization of multi-junction solar cells demands spectrally tunable solar simulators. The calibration of innovative multi-junction solar cells for CPV applications now requires tunable solar simulators which provide high irradiation levels. This paper describes the commissioning and calibration of a flash-based four-lamp simulator to be used for the measurement of multi-junction solar cells with up to four subcells under concentrated light.

    12. Junction Evolution During Fabrication of CdS/CdTe Thin-film PV Solar Cells (Presentation)

      SciTech Connect (OSTI)

      Gessert, T. A.

      2010-09-01

      Discussion of the formation of CdTe thin-film PV junctions and optimization of CdTe thin-film PV solar cells.

    13. Laser processing technique for fabricating series-connected and tandem junction series-connected solar cells into a solar battery

      DOE Patents [OSTI]

      Hanak, Joseph J.

      1981-01-01

      A method of fabricating series-connected and tandem junction series-connected solar cells into a solar battery with laser scribing.

    14. Increased efficiency in multijunction solar cells through the incorporation of semimetallic ErAs nanoparticles into the tunnel junction

      SciTech Connect (OSTI)

      Zide, J.M.O.; Kleiman-Shwarsctein, A.; Strandwitz, N.C.; Zimmerman, J.D.; Steenblock-Smith, T.; Gossard, A.C.; Forman, A.; Ivanovskaya, A.; Stucky, G.D.

      2006-04-17

      We report the molecular beam epitaxy growth of Al{sub 0.3}Ga{sub 0.7}As/GaAs multijunction solar cells with epitaxial, semimetallic ErAs nanoparticles at the interface of the tunnel junction. The states provided by these nanoparticles reduce the bias required to pass current through the tunnel junction by three orders of magnitude, and therefore drastically reduce the voltage losses in the tunnel junction. We have measured open-circuit voltages which are 97% of the sum of the constituent cells, which result in nearly double the efficiency of our multijunction cell with a conventional tunnel junction.

    15. Photocurrent spectroscopy of exciton and free particle optical transitions in suspended carbon nanotube pn-junctions

      SciTech Connect (OSTI)

      Chang, Shun-Wen; Theiss, Jesse; Hazra, Jubin; Aykol, Mehmet; Kapadia, Rehan; Cronin, Stephen B.

      2015-08-03

      We study photocurrent generation in individual, suspended carbon nanotube pn-junction diodes formed by electrostatic doping using two gate electrodes. Photocurrent spectra collected under various electrostatic doping concentrations reveal distinctive behaviors for free particle optical transitions and excitonic transitions. In particular, the photocurrent generated by excitonic transitions exhibits a strong gate doping dependence, while that of the free particle transitions is gate independent. Here, the built-in potential of the pn-junction is required to separate the strongly bound electron-hole pairs of the excitons, while free particle excitations do not require this field-assisted charge separation. We observe a sharp, well defined E{sub 11} free particle interband transition in contrast with previous photocurrent studies. Several steps are taken to ensure that the active charge separating region of these pn-junctions is suspended off the substrate in a suspended region that is substantially longer than the exciton diffusion length and, therefore, the photocurrent does not originate from a Schottky junction. We present a detailed model of the built-in fields in these pn-junctions, which, together with phonon-assistant exciton dissociation, predicts photocurrents on the same order of those observed experimentally.

    16. E-cadherin junction formation involves an active kinetic nucleation process

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

      Biswas, Kabir H.; Hartman, Kevin L.; Yu, Cheng -han; Harrison, Oliver J.; Song, Hang; Smith, Adam W.; Huang, William Y. C.; Lin, Wan -Chen; Guo, Zhenhuan; Padmanabhan, Anup; et al

      2015-08-19

      Epithelial (E)-cadherin-mediated cell–cell junctions play important roles in the development and maintenance of tissue structure in multicellular organisms. E-cadherin adhesion is thus a key element of the cellular microenvironment that provides both mechanical and biochemical signaling inputs. Here, we report in vitro reconstitution of junction-like structures between native E-cadherin in living cells and the extracellular domain of E-cadherin in a supported membrane. Junction formation in this hybrid live cell-supported membrane configuration requires both active processes within the living cell and a supported membrane with low E-cad-ECD mobility. The hybrid junctions recruit α-catenin and exhibit remodeled cortical actin. Observations suggest thatmore » the initial stages of junction formation in this hybrid system depend on the trans but not the cis interactions between E-cadherin molecules, and proceed via a nucleation process in which protrusion and retraction of filopodia play a key role.« less

    17. E-cadherin junction formation involves an active kinetic nucleation process

      SciTech Connect (OSTI)

      Biswas, Kabir H.; Hartman, Kevin L.; Yu, Cheng -han; Harrison, Oliver J.; Song, Hang; Smith, Adam W.; Huang, William Y. C.; Lin, Wan -Chen; Guo, Zhenhuan; Padmanabhan, Anup; Troyanovsky, Sergey M.; Dustin, Michael L.; Shapiro, Lawrence; Honig, Barry; Zaidel-Bar, Ronen; Groves, Jay T.

      2015-08-19

      Epithelial (E)-cadherin-mediated cell–cell junctions play important roles in the development and maintenance of tissue structure in multicellular organisms. E-cadherin adhesion is thus a key element of the cellular microenvironment that provides both mechanical and biochemical signaling inputs. Here, we report in vitro reconstitution of junction-like structures between native E-cadherin in living cells and the extracellular domain of E-cadherin in a supported membrane. Junction formation in this hybrid live cell-supported membrane configuration requires both active processes within the living cell and a supported membrane with low E-cad-ECD mobility. The hybrid junctions recruit α-catenin and exhibit remodeled cortical actin. Observations suggest that the initial stages of junction formation in this hybrid system depend on the trans but not the cis interactions between E-cadherin molecules, and proceed via a nucleation process in which protrusion and retraction of filopodia play a key role.

    18. Giant magnetoresistance modulated by magnetic field in graphene p-n junction

      SciTech Connect (OSTI)

      Li, Yuan; Jalil, Mansoor B. A.; Zhou, Guanghui

      2014-11-10

      We investigate the tunneling transport across a graphene p-n junction under the influence of a perpendicular magnetic field (B field). We observe a sideway deflection of the transmission profile, which can be quantitatively explained by invoking the classical Lorentz force. By considering the trajectory of the Dirac fermions along their cyclotron orbits, we analytically derive the incident angles for transmission across the graphene junction under a B field, as well as the critical magnetic field for full suppression of tunneling across the junction. These analytical predictions are consistent with the numerical results obtained via the non-equilibrium Green's function method. A stronger B-field conductance modulation is obtained for a p-n as opposed to an n-n or p-p type graphene junction. The magnetic field also induces a forbidden region of almost zero transmission for electron energy close to the Dirac point, which can be utilized to achieve a giant magnetoresistance effect. Based on our analysis, we devise an optimal magneto-electrical transport modulation, which can potentially realize a giant magnetoresistance effect in graphene p-n junction systems.

    19. Improved tunneling magnetoresistance at low temperature in manganite junctions grown by molecular beam epitaxy

      SciTech Connect (OSTI)

      Werner, R.; Kleiner, R.; Koelle, D.; Petrov, A. Yu.; Davidson, B. A.; Mino, L. Alvarez

      2011-04-18

      We report resistance versus magnetic field measurements for a La{sub 0.65}Sr{sub 0.35}MnO{sub 3}/SrTiO{sub 3}/La{sub 0.65}Sr{sub 0.35}MnO{sub 3} tunnel junction grown by molecular-beam epitaxy, that show a large field window of extremely high tunneling magnetoresistance (TMR) at low temperature. Scanning the in-plane applied field orientation through 360 deg., the TMR shows fourfold symmetry, i.e., biaxial anisotropy, aligned with the crystalline axis but not the junction geometrical long axis. The TMR reaches {approx}1900% at 4 K, corresponding to an interfacial spin polarization of >95% assuming identical interfaces. These results show that uniaxial anisotropy is not necessary for large TMR, and lay the groundwork for future improvements in TMR in manganite junctions.

    20. Sputtered a-silicon tunneling barriers for Nb-Nb Josephson junctions

      SciTech Connect (OSTI)

      Smith, L.N.; Jillie, D.W.; Kroger, H.; Thaxter, J.B.

      1982-11-01

      The authors have developed an IC-compatible process for fabricating Josephson tunnel junctions, which uses dc magnetron-sputtered Nb films as both base and counterelectrodes, and rf-sputtered amorphous silicon as the tunneling barrier. Optical reflectivity measurements have been used to study the silicon barrier, and to allow precise determination of the barrier thickness. The Josephson current density varies exponentially -over several orders of magnitude -- with the barrier thickness. The product of the critical current and subgap resistance V /SUB m/ is constant over this wide range of current density. The specific capacitance of these junctions is about 2.5 ..mu..f/cm/sup 2/ at a current density of a few hundred A/cm/sup 2/. This is lower than the value for lead-alloy junctions, about 4.3 ..mu..f/cm/sup 2/, and is consistent with the measured thickness and dielectric constant of the a-Si barrier.

    1. A versatile optical junction using photonic band-gap guidance and self collimation

      SciTech Connect (OSTI)

      Gupta, Man Mohan; Medhekar, Sarang

      2014-09-29

      We show that it is possible to design two photonic crystal (PC) structures such that an optical beam of desired wavelength gets guided within the line defect of the first structure (photonic band gap guidance) and the same beam gets guided in the second structure by self-collimation. Using two dimensional simulation of a design made of the combination of these two structures, we propose an optical junction that allows for crossing of two optical signals of same wavelength and same polarization with very low crosstalk. Moreover, the junction can be operated at number of frequencies in a wide range. Crossing of multiple beams with very low cross talk is also possible. The proposed junction should be important in future integrated photonic circuits.

    2. Two-band lasing in epitaxially stacked tunnel-junction semiconductor lasers

      SciTech Connect (OSTI)

      Vinokurov, D. A.; Ladugin, M. A.; Lyutetskii, A. V.; Marmalyuk, A. A.; Petrunov, A. N.; Pikhtin, N. A.; Slipchenko, S. O. Sokolova, Z. N.; Stankevich, A. L.; Fetisova, N. V.; Shashkin, I. S.; Averkiev, N. S.; Tarasov, I. S.

      2010-06-15

      Epitaxially stacked tunnel-junction laser hetero structures were grown by hydride metalorganic vapor-phase epitaxy in the system of AlGaAs/GaAs/In GaAs alloys. Based on such structures, mesa stripe lasers with an aperture of 150 s- 7 m were fabricated. The possibility of controlling the lasing wavelength by varying the active region thickness in each tunnel-junction laser structure was demonstrated. Independent two-band lasing at wavelengths of 914 and 925 nm (the difference frequency is 2.3 THz) was achieved at a maximum optical radiation power of 20 W in each band of the epitaxially stacked tunnel-junction semiconductor laser.

    3. UMTRA Project water sampling and analysis plan, Grand Junction, Colorado. Revision 1, Version 6

      SciTech Connect (OSTI)

      1995-09-01

      This water sampling and analysis plan describes the planned, routine ground water sampling activities at the Grand Junction US DOE Uranium Mill Tailings Remedial Action (UMTRA) Project site (GRJ-01) in Grand Junction, Colorado, and at the Cheney Disposal Site (GRJ-03) near Grand Junction. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequencies for the routine monitoring stations at the sites. Regulatory basis is in the US EPA regulations in 40 CFR Part 192 (1994) and EPA ground water quality standards of 1995 (60 FR 2854). This plan summarizes results of past water sampling activities, details water sampling activities planned for the next 2 years, and projects sampling activities for the next 5 years.

    4. US Department of Energy Grand Junction Projects Office Remedial Action Project, final report of the decontamination and decommissioning of Building 36 at the Grand Junction Projects Office Facility

      SciTech Connect (OSTI)

      Widdop, M.R.

      1996-08-01

      The U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore and mill tailings during uranium refining activities of the Manhattan Engineer District and during pilot milling experiments conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJPO Remedial Action Project to clean up and restore the facility lands, improvements, and the underlying aquifer. The site contractor for the facility, Rust Geotech, also is the remedial action contractor. Building 36 was found to be radiologically contaminated and was demolished in 1996. The soil beneath the building was remediated in accordance with identified standards and can be released for unlimited exposure and unrestricted use. This document was prepared in response to a DOE request for an individual final report for each contaminated GJPO building.

    5. Light-splitting photovoltaic system utilizing two dual-junction solar cells

      SciTech Connect (OSTI)

      Xiong, Kanglin; Yang, Hui; Lu, Shulong; Dong, Jianrong; Zhou, Taofei; Wang, Rongxin; Jiang, Desheng

      2010-12-15

      There are many difficulties limiting the further development of monolithic multi-junction solar cells, such as the growth of lattice-mismatched material and the current matching constraint. As an alternative approach, the light-splitting photovoltaic system is investigated intensively in different aspects, including the energy loss mechanism and the choice of energy bandgaps of solar cells. Based on the investigation, a two-dual junction system has been implemented employing lattice-matched GaInP/GaAs and InGaAsP/InGaAs cells grown epitaxially on GaAs and InP substrates, respectively. (author)

    6. Evaluation of power production from the solar electric generating systems at Kramer Junction: 1988 to 1993

      SciTech Connect (OSTI)

      Kolb, G.J.

      1994-12-31

      The five Solar Electric Generating Systems (SEGS) at Kramer Junction, California, now have nearly 30 years of cumulative operating experience. These 30 MW plants employ parabolic trough technology originally deployed by LUZ International in the late 1980`s and are now managed, operated and maintained by the Kramer Junction Company. In this paper, Sandia National Laboratories performed an analysis of the annual energy production from the five plants. Annual solar-to-electric conversion efficiencies are calculated and the major factors that influenced the results are presented. The generally good efficiencies are primarily attributed to the excellent equipment availabilities achieved at all plants.

    7. Hetero-junctions of Boron Nitride and Carbon Nanotubes: Synthesis and Characterization

      SciTech Connect (OSTI)

      Yap, Yoke Khin

      2013-03-14

      Hetero-junctions of boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) are expected to have appealing new properties that are not available from pure BNNTs and CNTs. Theoretical studies indicate that BNNT/CNT junctions could be multifunctional and applicable as memory, spintronic, electronic, and photonics devices with tunable band structures. This will lead to energy and material efficient multifunctional devices that will be beneficial to the society. However, experimental realization of BNNT/CNT junctions was hindered by the absent of a common growth technique for BNNTs and CNTs. In fact, the synthesis of BNNTs was very challenging and may involve high temperatures (up to 3000 degree Celsius by laser ablation) and explosive chemicals. During the award period, we have successfully developed a simple chemical vapor deposition (CVD) technique to grow BNNTs at 1100-1200 degree Celsius without using dangerous chemicals. A series of common catalyst have then been identified for the synthesis of BNNTs and CNTs. Both of these breakthroughs have led to our preliminary success in growing two types of BNNT/CNT junctions and two additional new nanostructures: 1) branching BNNT/CNT junctions and 2) co-axial BNNT/CNT junctions, 3) quantum dots functionalized BNNTs (QDs-BNNTs), 4) BNNT/graphene junctions. We have started to understand their structural, compositional, and electronic properties. Latest results indicate that the branching BNNT/CNT junctions and QDs-BNNTs are functional as room-temperature tunneling devices. We have submitted the application of a renewal grant to continue the study of these new energy efficient materials. Finally, this project has also strengthened our collaborations with multiple Department of Energy’s Nanoscale Science Research Centers (NSRCs), including the Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National Laboratory, and the Center for Integrated Nanotechnologies (CINTs) at Sandia National Laboratories

    8. A Monolithic Interconnected module with a tunnel Junction for Enhanced Electrical and Optical Performance

      SciTech Connect (OSTI)

      Murray, Christopher Sean; Wilt, David Morgan

      1999-06-30

      An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMs), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

    9. NREL, CSEM Jointly Set New Efficiency Record with Dual-Junction Solar Cell

      SciTech Connect (OSTI)

      2016-01-01

      Scientists set a new world record for converting non-concentrated sunlight into electricity using a dual-junction III-V/Si solar cell. National Renewable Energy Laboratory (NREL) and Swiss Center for Electronics and Microtechnology (CSEM) scientists have collaborated to create a novel tandem solar cell that operates at 29.8% conversion efficiency under non-concentrator (1-sun) conditions. In comparison, the 1-sun efficiency of a silicon (Si) single-junction solar cell is probably still a few years away from converging on its practical limit of about 26%.

    10. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

      DOE Patents [OSTI]

      Wanlass, M.W.

      1994-12-27

      A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

    11. Thin-film metal coated insulation barrier in a Josephson tunnel junction. [Patent application

      DOE Patents [OSTI]

      Hawkins, G.A.; Clarke, J.

      1975-10-31

      A highly stable, durable, and reproducible Josephson tunnel junction consists of a thin-film electrode of a hard superconductor, a thin oxide insulation layer over the electrode constituting a Josephson tunnel junction barrier, a thin-film layer of stabilizing metal over the barrier, and a second thin-film hard superconductive electrode over the stabilizing film. The thin stabilizing metal film is made only thick enough to limit penetration of the electrode material through the insulation layer so as to prevent a superconductive short.

    12. Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance

      DOE Patents [OSTI]

      Murray, Christopher S.; Wilt, David M.

      2000-01-01

      An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMS), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

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

      DOE Patents [OSTI]

      Sopori, Bhushan; Rangappan, Anikara

      2014-11-25

      Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

    14. McMillan-Rowell Like Oscillations in a Superconductor-InAs/GaSb-Superconductor Junction

      SciTech Connect (OSTI)

      Shi, Xiaoyan; Yu, Wenlong; Hawkins, Samuel D.; Klem, John F.; Pan, Wei

      2015-08-04

      We fabricated a superconductor (Ta)-InAs/GaSb bilayer-superconductor (Ta) junction device that has a long mean free path and can preserve the wavelike properties of particles (electrons and holes) inside the junction. Differential conductance measurements were also carried out at low temperatures in this device, and McMillan-Rowell like oscillations (MROs) were observed. A much larger Fermi velocity, compared to that from Shubnikov-de Haas oscillations, was obtained from the frequency of MROs. Possible mechanisms are discussed for this discrepancy.

    15. Effect of Front-Side Silver Metallization on Underlying n+-p Junction in Multicrystalline Silicon Solar Cells: Preprint

      SciTech Connect (OSTI)

      Jiang, C. S.; Li, Z. G.; Moutinho, H. R.; Liang, L.; Ionkin, A.; Al-Jassim, M. M.

      2012-06-01

      We report on the effect of front-side Ag metallization on the underlying n+-p junction of multicrystalline Si solar cells. The junction quality beneath the contacts was investigated by characterizing the uniformities of the electrostatic potential and doping concentration across the junction, using scanning Kelvin probe force microscopy and scanning capacitance microscopy. We investigated cells with a commercial Ag paste (DuPont PV159) and fired at furnace setting temperatures of 800 degrees, 840 degrees, and 930 degrees C, which results in actual cell temperatures ~100 degrees C lower than the setting temperature and the three cells being under-, optimal-, and over-fired. We found that the uniformity of the junction beneath the Ag contact was significantly degraded by the over-firing, whereas the junction retained good uniformity with the optimal- and under-fire temperatures. Further, Ag crystallites with widely distributed sizes from <100 nm to several μm were found at the Ag/Si interface of the over-fired cell. Large crystallites were imaged as protrusions into Si deeper than the junction depth. However, the junction was not broken down; instead, it was reformed on the entire front of the crystallite/Si interface. We propose a mechanism of the junction-quality degradation, based on emitter Si melting at the temperature around the Ag-Si eutectic point during firing, and subsequent recrystallization with incorporation of impurities in the Ag paste and with formation of crystallographic defects during quenching.

    16. Tuning electron transport through a single molecular junction by bridge modification

      SciTech Connect (OSTI)

      Li, Xiao-Fei Qiu, Qi; Luo, Yi

      2014-07-07

      The possibility of controlling electron transport in a single molecular junction represents the ultimate goal of molecular electronics. Here, we report that the modification of bridging group makes it possible to improve the performance and obtain new functions in a single cross-conjugated molecular junction, designed from a recently synthesized bipolar molecule bithiophene naphthalene diimide. Our first principles results show that the bipolar characteristic remains after the molecule was modified and sandwiched between two metal electrodes. Rectifying is the intrinsic characteristic of the molecular junction and its performance can be enhanced by replacing the saturated bridging group with an unsaturated group. A further improvement of the rectifying and a robust negative differential resistance (NDR) behavior can be achieved by the modification of unsaturated bridge. It is revealed that the modification can induce a deviation angle about 4° between the donor and the acceptor π-conjugations, making it possible to enhance the communication between the two π systems. Meanwhile, the low energy frontier orbitals of the junction can move close to the Fermi level and encounter in energy at certain biases, thus a transport channel with a considerable transmission can be formed near the Fermi level only at a narrow bias regime, resulting in the improvement of rectifying and the robust NDR behavior. This finding could be useful for the design of single molecular devices.

    17. Rapid, Enhanced IV Characterization of Multi-Junction PV Devices under One Sun at NREL

      SciTech Connect (OSTI)

      Moriarty, Tom; France, Ryan; Steiner, Myles

      2015-06-14

      Multi-junction technology is rapidly advancing, which puts increasing demands on IV characterization resources. We report on a tool and procedure for fast turn-around of IV data under the reference conditions, but also under controlled variations from the reference conditions. This enhanced data set can improve further iterations of device optimization.

    18. Rapid, Enhanced IV Characterization of Multi-Junction PV Devices under One Sun at NREL: Preprint

      SciTech Connect (OSTI)

      Moriarty, Tom; France, Ryan; Steiner, Myles

      2015-09-15

      Multi-junction technology is rapidly advancing, which puts increasing demands on IV characterization resources. We report on a tool and procedure for fast turn-around of IV data under the reference conditions, but also under controlled variations from the reference conditions. This enhanced data set can improve further iterations of device optimization.

    19. In situ Formation of Highly Conducting Covalent Au-C Contacts for Single-Molecule Junctions

      SciTech Connect (OSTI)

      Cheng, Z.L.; Hybertsen, M.; Skouta, R.; Vazquez, H.; Widawsky, J.R.; Schneebeli, S.; Chen, W.; Breslow, R.; Venkataraman, L.

      2011-06-01

      Charge transport across metal-molecule interfaces has an important role in organic electronics. Typically, chemical link groups such as thiols or amines are used to bind organic molecules to metal electrodes in single-molecule circuits, with these groups controlling both the physical structure and the electronic coupling at the interface. Direct metal-carbon coupling has been shown through C60, benzene and {pi}-stacked benzene but ideally the carbon backbone of the molecule should be covalently bonded to the electrode without intervening link groups. Here, we demonstrate a method to create junctions with such contacts. Trimethyl tin (SnMe{sub 3})-terminated polymethylene chains are used to form single-molecule junctions with a break-junction technique. Gold atoms at the electrode displace the SnMe{sub 3} linkers, leading to the formation of direct Au-C bonded single-molecule junctions with a conductance that is {approx}100 times larger than analogous alkanes with most other terminations. The conductance of these Au-C bonded alkanes decreases exponentially with molecular length, with a decay constant of 0.97 per methylene, consistent with a non-resonant transport mechanism. Control experiments and ab initio calculations show that high conductances are achieved because a covalent Au-C sigma ({sigma}) bond is formed. This offers a new method for making reproducible and highly conducting metal-organic contacts.

    20. Silicon Solar Cells with Front Hetero-Contact and Aluminum Alloy Back Junction: Preprint

      SciTech Connect (OSTI)

      Yuan, H.-C.; Page, M. R.; Iwaniczko, E.; Xu, Y.; Roybal, L.; Wang, Q.; Branz, H. M.; Meier, D. L.

      2008-05-01

      We prototype an alternative n-type monocrystalline silicon (c-Si) solar cell structure that utilizes an n/i-type hydrogenated amorphous silicon (a-Si:H) front hetero-contact and a back p-n junction formed by alloying aluminum (Al) with the n-type Si wafer.

    1. The importance of Fe surface states for spintronic devices based on magnetic tunnel junctions

      SciTech Connect (OSTI)

      Chantis, Athanasios N

      2008-01-01

      In this article we give a review of our recent theoretical studies of the influence of Fe(001) surface (interface) states on spin-polarized electron transport across magnetic tunnel junctions with Fe electrodes. We show that minority-spin surface (interface) states are responsible for at least two effects which are important for spin electronics. First, they can produce a sizable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single Fe electrode. The effect is driven by a Rashba shift of the resonant surface band when the magnetization changes direction. This can introduce a new class of spintronic devices, namely, tunneling magnetoresistance junctions with a single ferromagnetic electrode. Second, in Fe/GaAs(001) magnetic tunnel junctions minority-spin interface states produce a strong dependence of the tunneling current spin polarization on applied electrical bias. A dramatic sign reversal within a voltage range of just a few tenths of an eV is predicted. This explains the observed sign reversal of spin polarization in recent experiments of electrical spin injection in Fe/GaAs(001) and related reversal of tunneling magnetoresistance through vertical Fe/GaAs/Fe trilayers.

    2. Superconductive tunnel junction device with enhanced characteristics and method of manufacture

      SciTech Connect (OSTI)

      Kroger, H.; Jillie, D. W.

      1985-08-20

      A superconductive tunnel junction device comprises first and second superconductive electrodes with a barrier disposed therebetween where the first superconductive electrode and the barrier are formed without interruption in the same vacuum system pump down and with the first superconductive electrode subjected to sputter etching in an argon plasma before the deposition of the barrier for improving the characteristics of the device.

    3. Imaging the Solar Cell P-N Junction and Depletion Region Using Secondary Electron Contrast

      SciTech Connect (OSTI)

      Heath, J. T.; Jiang, C. S.; Al-Jassim, M. M.

      2011-01-01

      We report on secondary electron (SE) images of cross-sectioned multicrystalline Si and GaAs/GaInP solar cell devices, focusing on quantifying the relationship between the apparent n{sup +}-p contrast and characteristic electronic features of the device. These samples allow us to compare the SE signal from devices which have very different physical characteristics: differing materials, diffused junction versus abrupt junction, heterojunction versus homojunction. Despite these differences, we find that the SE image contrast for both types of sample, and as a function of reverse bias across the diode, closely agrees with PC1D simulations of the bulk electrostatic potential in the device, accurately yielding the depletion edge and width. A spatial derivative of the SE data shows a local maximum at the metallurgical junction. Such data are valuable, for example, in studying the conformity of a diffused junction to the textured surface topography. These data also extend our understanding of the origin of the SE contrast.

    4. Site observational work plan for the UMTRA Project Site at Grand Junction, Colorado

      SciTech Connect (OSTI)

      1996-03-01

      The U.S. Department of Energy (DOE) has prepared this initial site observational work plan (SOWP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project site in Grand Junction, Colorado. This SOWP is one of the first UMTRA Ground Water Project documents developed to select a compliance strategy that meets the UMTRA ground water standards (40 CFR Part 192, as amended by 60 FR 2854) for the Grand Junction site. This SOWP applies information about the Grand Junction site to the compliance strategy selection framework developed in the UMTRA Ground Water Project draft programmatic environmental impact statement (PEIS). This risk-based, decision-making framework identifies the decision logic for selecting compliance strategies that could be used to meet the ground water standards. The DOE goal is to use the observational method to implement a cost-effective site strategy that complies with the ground water standards and protects human health and the environment. Based on an evaluation of the site characterization and risk assessment data available for the preparation of this SOWP, DOE proposes that the most likely compliance strategy for the Grand Junction site is no remediation based on the application of supplemental standards. This proposed strategy is based on a conceptual site model that indicates site-related contamination is confined to a limited-use aquifer as defined in the ground water standards.

    5. Electrical and photovoltaic characteristics of MoS{sub 2}/Si p-n junctions

      SciTech Connect (OSTI)

      Hao, Lanzhong Liu, Yunjie Gao, Wei; Han, Zhide; Xue, Qingzhong; Zeng, Huizhong; Wu, Zhipeng; Zhu, Jun; Zhang, Wanli

      2015-03-21

      Bulk-like molybdenum disulfide (MoS{sub 2}) thin films were deposited on the surface of p-type Si substrates using dc magnetron sputtering technique and MoS{sub 2}/Si p-n junctions were formed. The vibrating modes of E{sup 1}{sub 2g} and A{sub 1g} were observed from the Raman spectrum of the MoS{sub 2} films. The current density versus voltage (J-V) characteristics of the junction were investigated. A typical J-V rectifying effect with a turn-on voltage of 0.2 V was shown. In different voltage range, the electrical transporting of the junction was dominated by diffusion current and recombination current, respectively. Under the light illumination of 15 mW cm{sup −2}, the p-n junction exhibited obvious photovoltaic characteristics with a short-circuit current density of 3.2 mA cm{sup −2} and open-circuit voltage of 0.14 V. The fill factor and energy conversion efficiency were 42.4% and 1.3%, respectively. According to the determination of the Fermi-energy level (∼4.65 eV) and energy-band gap (∼1.45 eV) of the MoS{sub 2} films by capacitance-voltage curve and ultraviolet-visible transmission spectra, the mechanisms of the electrical and photovoltaic characteristics were discussed in terms of the energy-band structure of the MoS{sub 2}/Si p-n junctions. The results hold the promise for the integration of MoS{sub 2} thin films with commercially available Si-based electronics in high-efficient photovoltaic devices.

    6. TH-C-BRD-12: Robust Intensity Modulated Proton Therapy Plan Can Eliminate Junction Shifts for Craniospinal Irradiation

      SciTech Connect (OSTI)

      Liao, L; Jiang, S; Li, Y; Wang, X; Li, H; Zhu, X; Sahoo, N; Gillin, M; Mahajan, A; Grosshans, D; Zhang, X; Lim, G

      2014-06-15

      Purpose: The passive scattering proton therapy (PSPT) technique is the commonly used radiotherapy technique for craniospinal irradiation (CSI). However, PSPT involves many numbers of junction shifts applied over the course of treatment to reduce the cold and hot regions caused by field mismatching. In this work, we introduced a robust planning approach to develop an optimal and clinical efficient techniques for CSI using intensity modulated proton therapy (IMPT) so that junction shifts can essentially be eliminated. Methods: The intra-fractional uncertainty, in which two overlapping fields shift in the opposite directions along the craniospinal axis, are incorporated into the robust optimization algorithm. Treatment plans with junction sizes 3,5,10,15,20,25 cm were designed and compared with the plan designed using the non-robust optimization. Robustness of the plans were evaluated based on dose profiles along the craniospinal axis for the plans applying 3 mm intra-fractional shift. The dose intra-fraction variations (DIV) at the junction are used to evaluate the robustness of the plans. Results: The DIVs are 7.9%, 6.3%, 5.0%, 3.8%, 2.8% and 2.2%, for the robustly optimized plans with junction sizes 3,5,10,15,20,25 cm. The DIV are 10% for the non-robustly optimized plans with junction size 25 cm. The dose profiles along the craniospinal axis exhibit gradual and tapered dose distribution. Using DIVs less than 5% as maximum acceptable intrafractional variation, the overlapping region can be reduced to 10 cm, leading to potential reduced number of the fields. The DIVs are less than 5% for 5 mm intra-fractional shifts with junction size 25 cm, leading to potential no-junction-shift for CSI using IMPT. Conclusion: This work is the first report of the robust optimization on CSI based on IMPT. We demonstrate that robust optimization can lead to much efficient carniospinal irradiation by eliminating the junction shifts.

    7. 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.

    8. Spin and charge transport in double-junction Fe/MgO/GaAs/MgO/Fe heterostructures

      SciTech Connect (OSTI)

      Wolski, S. Szczepa?ski, T.; Dugaev, V. K.; Barna?, J.; Landgraf, B.; Slobodskyy, T.; Hansen, W.

      2015-01-28

      We present theoretical and experimental results on tunneling current in single Fe/MgO/GaAs and double Fe/MgO/GaAs/MgO/Fe tunnel junctions. The charge and spin currents are calculated as a function of external voltage for different sets of parameters characterizing the semiconducting GaAs layer. Transport characteristics of a single Fe/MgO/GaAs junction reveal typical diode as well as spin diode features. The results of numerical calculations are compared with current-voltage characteristics measured experimentally for double tunnel junction structures, and a satisfactory agreement of the theoretical and experimental results has been achieved.

    9. Correlation between amplitude of spin accumulation signals investigated by Hanle effect measurement and effective junction barrier height in CoFe/MgO/n{sup +}-Si junctions

      SciTech Connect (OSTI)

      Saito, Y. Ishikawa, M.; Sugiyama, H.; Inokuchi, T.; Hamaya, K.; Tezuka, N.

      2015-05-07

      Correlation between the amplitude of the spin accumulation signals and the effective barrier height estimated from the slope of the log (RA) - t{sub MgO} plot (RA: resistance area product, t{sub MgO}: thickness of MgO tunnel barrier) in CoFe/MgO/n{sup +}-Si junctions was investigated. The amplitude of spin accumulation signals increases with increasing effective barrier heights. This increase of the amplitude of spin accumulation is originated from the increase of the spin polarization (P{sub Si}) in Si. The estimated absolute values of P{sub Si} using three-terminal Hanle signals are consistent with those estimated by four-terminal nonlocal-magnetoresistance (MR) and two-terminal local-MR. To demonstrate large spin accumulation in Si bulk band and enhance the local-MR through Si channel, these results indicate that the increase of the effective barrier height at ferromagnet/(tunnel barrier)/n{sup +}-Si junction electrode is important.

    10. US Department of Energy Grand Junction Projects Office Remedial Action Project. Final report of the decontamination and decommissioning of Building 52 at the Grand Junction Projects Office Facility

      SciTech Connect (OSTI)

      Krabacher, J.E.

      1996-08-01

      The U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore and mill tailings during uranium refining activities of the Manhattan Engineer District and during pilot milling experiments conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJPO Remedial Action Project to clean up and restore the facility lands, improvements, and the underlying aquifer. The site contractor for the facility, Rust Geotech, also was the remedial action contractor. Building 52 was found to be radiologically contaminated and was demolished in 1994. The soil area within the footprint of the building has been remediated in accordance with the identified standards and the area can be released for unlimited exposure and unrestricted use. This document was prepared in response to a DOE request for an individual final report for each contaminated GJPO building.

    11. Multiple junction cell characterization using the LBIC method : early results, issues, and pathways to improvement.

      SciTech Connect (OSTI)

      Finn, Jason R.; Granata, Jennifer E.; Hansen, Barry R.

      2010-03-01

      A light beam induced current (LBIC) measurement is a non-destructive technique that produces a spatial graphical representation of current response in photovoltaic cells with respect to position when stimulated by a light beam. Generally, a laser beam is used for these measurements because the spot size can be made very small, on the order of microns, and very precise measurements can be made. Sandia National Laboratories Photovoltaic System Evaluation Laboratory (PSEL) uses its LBIC measurement technique to characterize single junction mono-crystalline and multi-crystalline solar cells ranging from miniature to conventional sizes. Sandia has modified the already valuable LBIC technique to enable multi-junction PV cells to be characterized.

    12. Vector spin modeling for magnetic tunnel junctions with voltage dependent effects

      SciTech Connect (OSTI)

      Manipatruni, Sasikanth Nikonov, Dmitri E.; Young, Ian A.

      2014-05-07

      Integration and co-design of CMOS and spin transfer devices requires accurate vector spin conduction modeling of magnetic tunnel junction (MTJ) devices. A physically realistic model of the MTJ should comprehend the spin torque dynamics of nanomagnet interacting with an injected vector spin current and the voltage dependent spin torque. Vector spin modeling allows for calculation of 3 component spin currents and potentials along with the charge currents/potentials in non-collinear magnetic systems. Here, we show 4-component vector spin conduction modeling of magnetic tunnel junction devices coupled with spin transfer torque in the nanomagnet. Nanomagnet dynamics, voltage dependent spin transport, and thermal noise are comprehended in a self-consistent fashion. We show comparison of the model with experimental magnetoresistance (MR) of MTJs and voltage degradation of MR with voltage. Proposed model enables MTJ circuit design that comprehends voltage dependent spin torque effects, switching error rates, spin degradation, and back hopping effects.

    13. Giant amplification of tunnel magnetoresistance in a molecular junction: Molecular spin-valve transistor

      SciTech Connect (OSTI)

      Dhungana, Kamal B.; Pati, Ranjit

      2014-04-21

      Amplification of tunnel magnetoresistance by gate field in a molecular junction is the most important requirement for the development of a molecular spin valve transistor. Herein, we predict a giant amplification of tunnel magnetoresistance in a single molecular spin valve junction, which consists of Ru-bis-terpyridine molecule as a spacer between two ferromagnetic nickel contacts. Based on the first-principles quantum transport approach, we show that a modest change in the gate field that is experimentally accessible can lead to a substantial amplification (320%) of tunnel magnetoresistance. The origin of such large amplification is attributed to the spin dependent modification of orbitals at the molecule-lead interface and the resultant Stark effect induced shift in channel position with respect to the Fermi energy.

    14. Perpendicular magnetic tunnel junctions with double barrier and single or synthetic antiferromagnetic storage layer

      SciTech Connect (OSTI)

      Cuchet, La; Rodmacq, Bernard; Auffret, Stphane; Sousa, Ricardo C.; Prejbeanu, Ioan L.; Dieny, Bernard

      2015-06-21

      The magnetic properties of double tunnel junctions with perpendicular anisotropy were investigated. Two synthetic antiferromagnetic references are used, while the middle storage magnetic layer can be either a single ferromagnetic or a synthetic antiferromagnetic FeCoB-based layer, with a critical thickness as large as 3.0?nm. Among the different achievable magnetic configurations in zero field, those with either antiparallel references, and single ferromagnetic storage layer, or parallel references, and synthetic antiferromagnetic storage layer, are of particular interest since they allow increasing the efficiency of spin transfer torque writing and the thermal stability of the stored information as compared to single tunnel junctions. The latter configuration can be preferred when stray fields would favour a parallel orientation of the reference layers. In this case, the synthetic antiferromagnetic storage layer is also less sensitive to residual stray fields.

    15. Assessing thermal damage in silicon PN-junctions using Raman thermometry

      SciTech Connect (OSTI)

      Beechem, Thomas E.; Serrano, Justin R.; McDonald, Anthony; Mani, Seethambal

      2013-03-28

      Laser machining is frequently utilized in the manufacture of photovoltaics. A natural by-product of these fabrication processes, heat, not only serves as a means of material removal but also modifies the material in an extended region beyond that ideally intended for alteration. This modified region, termed the heat affected zone, is detrimental to performance and should therefore be minimized. While undoubtedly thermal in origin, it is unclear exactly how the thermal environment during laser machining correlates to changes in the PN-junction that reduce performance. In response, we combine in-situ Raman based thermometry measurements with post-event failure analysis to identify the physical mechanisms damaging the junction during laser machining. From this approach, damage is shown to initiate prior to melting and be driven primarily by the diffusion of dopants for fluences that do not induce ablation. Additionally, comparatively small regions of damage are shown to have a large impact on operation.

    16. Proximity induced vortices and long-range triplet supercurrents in ferromagnetic Josephson junctions and spin valves

      SciTech Connect (OSTI)

      Alidoust, Mohammad; Halterman, Klaus

      2015-03-28

      Using a spin-parameterized quasiclassical Keldysh-Usadel technique, we theoretically study supercurrent transport in several types of diffusive ferromagnetic (F)/superconducting (S) configurations with differing magnetization textures. We separate out the even- and odd-frequency components of the supercurrent within the low proximity limit and identify the relative contributions from the singlet and triplet channels. We first consider inhomogeneous one-dimensional Josephson structures consisting of a uniform bilayer magnetic S/F/F/S structure and a trilayer S/F/F/F/S configuration, in which case the outer F layers can have either a uniform or conical texture relative to the central uniform F layer. Our results demonstrate that for supercurrents flowing perpendicular to the F/F interfaces, incorporating a conical texture yields the most effective way to observe the signatures of long-ranged spin-triplet supercurrents. We also consider three different types of finite-sized two-dimensional magnetic structures subjected to an applied magnetic field normal to the junction plane: a S/F/S junction with uniform magnetization texture and two S/F/F/S configurations with differing F/F bilayer arrangements. In one case, the F/F interface is parallel with the S/F junction interfaces while in the other case, the F/F junction is oriented perpendicular to the S/F interfaces. We then discuss the proximity vortices and corresponding spatial maps of currents inside the junctions. For the uniform S/F/S junction, we analytically calculate the magnetic field induced supercurrent and pair potential in both the narrow and wide junction regimes, thus providing insight into the variations in the Fraunhofer diffraction patterns and proximity vortices when transitioning from a wide junction to a narrow one. Our extensive computations demonstrate that the induced long-range spin-triplet supercurrents can deeply penetrate uniform F/F bilayers when spin-singlet supercurrents flow parallel to the

    17. EIS-0126: Remedial Actions at the Former Climax Uranium Company Uranium Mill Site, Grand Junction, Mesa County, Colorado

      Broader source: Energy.gov [DOE]

      The U.S. Department of Energy developed this EIS to assess the environmental impacts of remediating the residual radioactive materials left from the inactive uranium processing site and associated properties located in Grand Junction, Colorado.

    18. Electronic transport in biphenyl single-molecule junctions with carbon nanotubes electrodes: The role of molecular conformation and chirality

      SciTech Connect (OSTI)

      Brito Silva, C. A. Jr.; Granhen, E. R. [Pos-Graduacao em Engenharia Eletrica, Universidade Federal do Para, 66075-900 Belem, PA (Brazil); Silva, S. J. S. da; Leal, J. F. P. [Pos-Graduacao em Fisica, Universidade Federal do Para, 66075-110 Belem, PA (Brazil); Del Nero, J. [Departamento de Fisica, Universidade Federal do Para, 66075-110 Belem, PA (Brazil); Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, 25250-020 Duque de Caxias, RJ (Brazil); Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ (Brazil); Pinheiro, F. A. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ (Brazil)

      2010-08-15

      We investigate, by means of ab initio calculations, electronic transport in molecular junctions composed of a biphenyl molecule attached to metallic carbon nanotubes. We find that the conductance is proportional to cos{sup 2} {theta}, with {theta} the angle between phenyl rings, when the Fermi level of the contacts lies within the frontier molecular orbitals energy gap. This result, which agrees with experiments in biphenyl junctions with nonorganic contacts, suggests that the cos{sup 2} {theta} law has a more general applicability, irrespective of the nature of the electrodes. We calculate the geometrical degree of chirality of the junction, which only depends on the atomic positions, and demonstrate that it is not only proportional to cos{sup 2} {theta} but also is strongly correlated with the current through the system. These results indicate that molecular conformation plays the preponderant role in determining transport properties of biphenyl-carbon nanotubes molecular junctions.

    19. Superlinear generation of exciton and related paramagnetism induced by forward current in a diamond p-i-n junction

      SciTech Connect (OSTI)

      Natori, Kenji

      2015-02-07

      The concentration of excitons generated in a high-quality diamond p-i-n junction is investigated considering the forward current characteristics of the junction. As the forward current in the junction increases, the exciton concentration increases superlinearly, contrary to the linear increases of the electron and hole concentration. This tendency suggests a superlinear increase in emission intensity due to exciton recombination. The increase rate is more radical than quadratic, in accordance with the observed increase of the integrated intensity of free exciton emission. To estimate the concentration of triplet excitons generated in the p-i-n junction, observation of the paramagnetism due to the exciton spin moment is proposed. The magnetic susceptibility superlinearly increases with the increase in the forward current, unlike any other magnetic property of the device.

    20. U.S. Department of Energy at Grand Junction 2003 Annual Inspection⎯Monticello, Utah

      Office of Legacy Management (LM)

      at Grand Junction 2003 Annual Inspection⎯Monticello, Utah November 2003 Page 1 2003 Annual Inspection of the Monticello Mill Tailings (USDOE) and Monticello Radioactively Contaminated Properties Sites Summary The Monticello site, which includes the U.S. Department of Energy (DOE) Monticello Mill Tailings Site (MMTS) and the Monticello Radioactively Contaminated Properties site, was inspected September 23-25, 2003. A follow-up inspection of the Soil and Sediment properties was conducted on

    1. NREL's Multi-Junction Solar Cells Teach Scientists How to Turn Plants into

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

      Powerhouses - News Releases | NREL NREL's Multi-Junction Solar Cells Teach Scientists How to Turn Plants into Powerhouses May 12, 2011 Plants can overcome their evolutionary legacies to become much better at using biological photosynthesis to produce energy, the kind of energy that can power vehicles in the near future, an all-star collection of biologists, physicists, photochemists, and solar scientists has found. A U.S. Department of Energy (DOE) workshop that drew a prestigious collection

    2. In the OSTI Collections: Josephson Junctions | OSTI, US Dept of Energy

      Office of Scientific and Technical Information (OSTI)

      Office of Scientific and Technical Information Josephson Junctions Article Acknowledgement: Dr. William N. Watson, Physicist DOE Office of Scientific and Technical Information Terahertz Radiation Examining Subatomic Particles Measuring Material Properties Noise Spin and Supercurrents References Research Organizations Reports available through OSTI's SciTech Connect Additional References When a steady voltage gradient is applied along an ordinary conducting wire, electrons in the wire will

    3. The influence of electron irradiation on electron holography of focused ion beam milled GaAs p-n junctions

      SciTech Connect (OSTI)

      Cooper, David; Twitchett-Harrison, Alison C.; Midgley, Paul A.; Dunin-Borkowski, Rafal E.

      2007-05-01

      Electron beam irradiation is shown to significantly influence phase images recorded from focused ion beam milled GaAs p-n junction specimens examined using off-axis electron holography in the transmission electron microscope. Our results show that the use of improved electrical connections to the specimen overcomes this problem, and may allow the correct built in potential across the junction to be recovered.

    4. Terahertz time domain interferometry of a SIS tunnel junction and a quantum point contact

      SciTech Connect (OSTI)

      Karadi, C

      1995-09-01

      The author has applied the Terahertz Time Domain Interferometric (THz-TDI) technique to probe the ultrafast dynamic response of a Superconducting-Insulating-Superconducting (SIS) tunnel junction and a Quantum Point Contact (QPC). The THz-TDI technique involves monitoring changes in the dc current induced by interfering two picosecond electrical pulses on the junction as a function of time delay between them. Measurements of the response of the Nb/AlO{sub x}/Nb SIS tunnel junction from 75--200 GHz are in full agreement with the linear theory for photon-assisted tunneling. Likewise, measurements of the induced current in a QPC as a function of source-drain voltage, gate voltage, frequency, and magnetic field also show strong evidence for photon-assisted transport. These experiments together demonstrate the general applicability of the THz-TDI technique to the characterization of the dynamic response of any micron or nanometer scale device that exhibits a non-linear I-V characteristic. 133 refs., 49 figs.

    5. Competition between cotunneling, Kondo effect, and direct tunneling in discontinuous high-anisotropy magnetic tunnel junctions

      SciTech Connect (OSTI)

      Ciudad D.; Arena D.; We, Z.-C.; Hindmarch, A.T.; Negusse, E.; Han, X.-F.Han; Marrows, C.H.

      2012-06-07

      The transition between Kondo and Coulomb blockade effects in discontinuous double magnetic tunnel junctions is explored as a function of the size of the CoPt magnetic clusters embedded between AlO{sub x} tunnel barriers. A gradual competition between cotunneling enhancement of the tunneling magnetoresistance (TMR) and the TMR suppression due to the Kondo effect has been found in these junctions, with both effects having been found to coexist even in the same sample. It is possible to tune between these two states with temperature (at a temperature far below the cluster blocking temperature). In addition, when further decreasing the size of the CoPt clusters, another gradual transition between the Kondo effect and direct tunneling between the electrodes takes place. This second transition shows that the spin-flip processes found in junctions with impurities in the barrier are in fact due to the Kondo effect. A simple theoretical model able to account for these experimental results is proposed.

    6. National Uranium Resource Evaluation. Bibliographic index of Grand Junction office uranium reports

      SciTech Connect (OSTI)

      Johnson, J.B.

      1981-05-01

      In October 1978, Mesa College entered into subcontract with Bendix Field Engineering Corporation (BFEC) to prepare a bibliographic index of the uranium raw materials reports issued by the Grand Junction Office of the US Department of Energy (DOE). Bendix, prime contractor to the Grand Junction Office, operates the Technical Library at the DOE facility. Since the early 1950s, approximately 2700 reports have been issued by the Grand Junction Office. These reports were the results of uranium investigations conducted by federal agencies and their subcontractors. The majority of the reports cover geology, mineralogy, and metallurgy of uranium and/or thorium. No single, complete list of these reports existed. The purpose of this subcontract was to compile a comprehensive index to these reports. The Mesa College geology faculty worked with the BFEC and DOE staffs to develop the format for the index. Undergraduate geology students from Mesa compiled a master record sheet for each report. All reports issued up to January 1, 1979 were included in the bibliography. The bibliography is in preliminary, unedited form. It is being open-filed at this time, on microfiche, to make the information available to the public on a timely basis. The bibliography is divided into a master record list arranged in alpha-numeric order by report identification number, with separate indices arranged by title, author, state and county, 1/sup 0/ x 2/sup 0/ NTMS quadrangle, key words, and exploration area.

    7. Work plan for ground water elevation data recorder/monitor well injection at Grand Junction, Colorado

      SciTech Connect (OSTI)

      Not Available

      1994-07-18

      The purpose of this document is to describe the work that will be performed and the procedures that will be followed during installation of ground water monitor wells and ground water elevation data recorders (data loggers) at the Grand Junction, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project site. The monitor wells and data loggers will be used to gather required time-dependent data to investigate the interaction between the shallow aquifer and the Colorado River. Data collection objectives (DCO) identify reasons for collecting data. The following are DCOs for the Grand Junction ground water elevation data recorder/monitor well installation project: long-term continuous ground water level data and periodic ground water samples will be collected to better understand the relationship between surface and ground water at the site; water level and water quality data will eventually be used in future ground water modeling to more firmly establish boundary conditions in the vicinity of the Grand Junction processing site; modeling results will be used to demonstrate and document the potential remedial alternative of natural flushing.

    8. Site observational work plan for the UMTRA project site at Grand Junction, Colorado

      SciTech Connect (OSTI)

      1996-01-01

      This site observational work plan (SOWP) is one of the first Uranium Mill Tailings Remedial Action (UMTRA) Ground Water Project documents developed to select a compliance strategy that meets the UMTRA ground water standards for the Grand Junction site. This SOWP applies information about the Grand Junction site to the compliance strategy selection framework developed in the UMTRA Ground Water Project draft programmatic environmental impact statement. This risk-based, decision-making framework identifies the decision logic for selecting compliance strategies that could be used to meet the ground water standards. The US Department of Energy (DOE) goal is to implement a cost-effective site strategy that complies with the ground water standards and protects human health and the environment. Based on an evaluation of the site characterization and risk assessment data available for the preparation of this SOWP, DOE proposes that the most likely compliance strategy for the Grand Junction site is no remediation with the application of supplemental standards. This proposed strategy is based on a conceptual site model that indicates site-related contamination is confined to a limited-use aquifer as defined in the ground water standards. The conceptual model demonstrates that the uranium processing-related contamination at the site has affected the unconfined alluvial aquifer, but not the deeper confined aquifer.

    9. Final report of the radiological release survey of Building 11 at the Grand Junction Office Facility

      SciTech Connect (OSTI)

      Johnson, R.K.; Corle, S.G.

      1997-09-01

      The U.S. Department of Energy (DOE) Grand Junction Office (GJO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore concentrates and mill tailings during vanadium refining activities of the Manhattan Engineer District, and during sampling, assaying, pilot milling, storage, and brokerage activities conducted for the U.S. Atomic Energy Commission`s domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJO Remedial Action Project (GJORAP) to clean up and restore the facility lands, improvements, and underlying aquifer. WASTREN-Grand Junction is the site contractor for the facility and the remedial action contractor for GJORAP. Building 11 and the underlying soil were found not to be radiologically contaminated; therefore, the building can be released for unrestricted use. Placards have been placed at the building entrances indicating the completion of the radiological release survey and prohibiting the introduction of any radioactive materials within the building without written approvals from the GJO Facilities Operations Manager. This document was prepared in response to a DOE-GJO request for an individual final release report for each GJO building.

    10. Final audit report of remedial action construction at the UMTRA Project, Grand Junction, Colorado, processing site

      SciTech Connect (OSTI)

      1995-02-01

      This final audit report (FAR) for remedial action at the Grand Junction, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project processing site consists of a summary of the radiological surveillances/ audits, the quality assurance (QA) in-process surveillances, and the QA final close-out inspection performed by the US Department of Energy (DOE) and Technical Assistance Contractor (TAC). The FAR also summarizes other surveillances performed by the US Nuclear Regulatory Commission (NRC). To summarize, a total of one finding and 127 observations were noted during DOE/TAC audit and surveillance activities. The NRC noted general site-related observations during the OSCRs. Follow-up to responses required from MK-Ferguson for the DOE/TAC finding and observations indicated that all issues related to the Grand Junction processing site were resolved and closed out to the DOE`s satisfaction. The NRC OSCRs resulted in no issues related to the Grand Junction processing site requiring a response from MK-Ferguson.