Sample records for guatemala se mencionan

  1. Volcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, Guatemala 1111

    E-Print Network [OSTI]

    Rose, William I.

    Volcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, Guatemala 11111 Open-File Report 01­431Open-File Report 01

  2. Guatemala: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

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

  3. RURAL-FRONTIER MIGRATION AND DEFORESTATION IN THE SIERRA DE LACANDON NATIONAL PARK, GUATEMALA

    E-Print Network [OSTI]

    Lopez-Carr, David

    RURAL-FRONTIER MIGRATION AND DEFORESTATION IN THE SIERRA DE LACANDON NATIONAL PARK, GUATEMALA-frontier Migration and Deforestation in the Sierra de Lacandón National Park, Guatemala (Under the direction of deforestation in the Sierra de Lacandón Park (SLNP), Petén, Guatemala. To explore the first cause

  4. Scientific Notes 649 LEPIDOPTERA ASSOCIATED WITH AVOCADO FRUIT IN GUATEMALA

    E-Print Network [OSTI]

    Hoddle, Mark S.

    Scientific Notes 649 LEPIDOPTERA ASSOCIATED WITH AVOCADO FRUIT IN GUATEMALA MARK S. HODDLE1 History, Smithsonian Institution, Washington, DC 20013, U.S.A Avocados (Persea americana Miller) (Lau of Central America (Knight 2002). Humans moved avocados into northern South America by 4000 BC where plants

  5. A Study of Sustainable Compost Micro-Enterprise In Chimaltenango, Guatemala: Profitability and Employee Characteristics 

    E-Print Network [OSTI]

    Silberg, Timothy

    2012-02-14T23:59:59.000Z

    Over 13 million people live in Guatemala, and among this population more than 50% live below the poverty line. One proposed solution to mitigate the large percentage of poverty in the country is micro-entrepreneurship. ...

  6. Needs Assessment of Agricultural, Environmental, and Social Systems of Small Farmers in Chimaltenango, Guatemala 

    E-Print Network [OSTI]

    Oleas, Carolina

    2011-02-22T23:59:59.000Z

    Providing support for the agricultural development of small farmers is the main goal of the project Agriculture in Guatemala: Technology, Education and Commercialization (AGTEC). To accomplish this, it is necessary, to ...

  7. A survey of geothermal process heat applications in Guatemala: An engineering survey

    SciTech Connect (OSTI)

    Altseimer, J.H.; Edeskuty, F.J.

    1988-08-01T23:59:59.000Z

    This study investigates how process heat from Guatemala's geothermal energy resources can be developed to reduce Guatemala's costly importation of oil, create new employment by encouraging new industry, and reduce fuel costs for existing industry. This investigation was funded by the US Agency for International Development and carried out jointly by the Guatemalan Government and the Los Alamos National Laboratory. Two sites, Amatitlan and Zunil, are being developed geothermally. Amatitlan is in the better industrial area but Zunil's geothermal development is more advanced. The industry around Zunil is almost exclusively agricultural and the development of an agricultural processing plant (freezing, dehydration, and cold storage) using geothermal heat is recommended. Similar developments throughout the volcanic zones of Guatemala are possible. Later, when the field at Amatitlan has been further developed, an industrial park can be planned. Potential Amatitlan applications are the final stage of salt refining, a thermal power plant, hospital/hotel heating and cooling, steam curing of concrete blocks, production of alcohol from sugar cane, and production of polyethylene from ethanol. Other special developments such as water pumping for the city of Guatemala and the use of moderate-temperature geothermal fluids for localized power production are also possible. 12 refs., 13 figs., 14 tabs.

  8. Creating the political spectacle during the Cold War: Guatemala and the United States

    E-Print Network [OSTI]

    Burton, Michael Cassidy

    2013-02-22T23:59:59.000Z

    Arbenz and Maj. Francisco Arana, sponsored popular democratic elections in which Juan Jose Arevalo, a "professor from the University of Tucuman*', was elected to the presidency. Arevalo's regime 8 ' This brief summary of Guatemala's history leading up... formed and smaller political parties came into being. Arana was presumed to bc the next president elect and in a prideful move demanded Arevalo relinquish power before his term was up. Arevalo requested some time to consider Arana's proposal, and while...

  9. A Comparative Analysis of Mestizo and Indigenous Mayan Young Women in Guatemala: Attitudes and Knowledge of Sexual Reproduction and Health among Members of Children International's Youth Health Corps

    E-Print Network [OSTI]

    Trapp, Sarah Casement

    2011-04-21T23:59:59.000Z

    Children International’s Youth Health Corps Program uses Peer Education techniques to teach impoverished adolescents about Sexual Health and Reproduction. In the Youth Health Corps in Guatemala, both rural indigenous Maya ...

  10. Through the Lens of Pater-Americanism: A Comparative Analysis of the Eisenhower Administration's Perception of Guatemala and Bolivia, 1953 and 1954

    E-Print Network [OSTI]

    Moulton, Aaron Coy

    2009-06-06T23:59:59.000Z

    This thesis examines the diverging responses of the Eisenhower Administration in the US to the Arbenz government in Guatemala and the Paz government in Bolivia in 1953 and 1954. This divergence occurred in spite of strong similarities between...

  11. De de se

    E-Print Network [OSTI]

    Anand, Pranav

    2006-01-01T23:59:59.000Z

    In this dissertation, I argue against a unitary treatment of individual de se ascription. Based on consideration of Yoruba logophors and English dream-report pronouns, I show that one mechanism is best analyzed as binding ...

  12. La prise en compte des populations locales dans la mise en place d'aires protges : tudes de cas au Guatemala et au Maroc

    E-Print Network [OSTI]

    Vellend, Mark

    au Guatemala et au Maroc Par Vincens Côté essai présenté au Département de biologie pour l la gestion de deux aires protégées, l'une au Guatemala et l'autre au Maroc, et tente d'en dégager des scientifiques ont été utilisés pour déterminer la nature de la protection. Au Maroc, les premières lois sur les

  13. El laberinto de la indigenidad: Cómo se determina quién es indígena maya ch’orti’ en Guatemala, Honduras y El Salvador

    E-Print Network [OSTI]

    Metz, Brent

    2012-01-01T23:59:59.000Z

    idioma primero y privilegiado de Dios. Dios prefiere oraciones en ch’orti’. Las fuerzas de la naturaleza personificadas en santos, como las cuatro direcciones, el sol, la tierra, el agua y el viento, son fundamentales en la visión tradicional del..., una dieta con altos porcentajes de maíz y frijoles cocinados con recetas antiguas, trabajo agrícola sin maquinaria, baja educación e incluso menosprecio hacia ella, el uso de yerbas medicinales y la producción de artesanías utilitarias. La raíz de...

  14. Examining the Proximate and Underlying Causes of Tropical Deforestation: Migration and Land Use in the Sierra de Lacandn National Park, Guatemala1

    E-Print Network [OSTI]

    Lopez-Carr, David

    1 Examining the Proximate and Underlying Causes of Tropical Deforestation: Migration and Land Use In explaining variability in tropical deforestation, scholars have focused almost exclusively on in situ (or "on causes of deforestation in the humid tropics with a case study from Guatemala. To investigate the first

  15. Proximate and Underlying Causes of Tropical Deforestation: The Event Ecology of Migration and Forest Conversion in the Sierra de Lacandn National Park, Guatemala1

    E-Print Network [OSTI]

    Lopez-Carr, David

    1 Proximate and Underlying Causes of Tropical Deforestation: The Event Ecology of Migration deforestation, scholars of land use/cover change (LUCC) have focused almost exclusively on in situ (or "on causes of deforestation in the humid tropics with a case study from Guatemala. To investigate the first

  16. Bioavailability of Particle-Associated Se to the Bivalve Potamocorbula

    E-Print Network [OSTI]

    of Se(0) by generatingradioisotopic75Se(0)throughbacterialdissimilatory reduction of 75SeO3 2- by pure by reducing 75SeO3 2- with ascorbic acid (AA). Speciation determinations showed that AA and SES were >90% Se(0. After 113 d of incubation, 36% of SES Se(0) was oxidized to SeO3 2-. Assimilation of total particulate

  17. Q Cells SE | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with form History Facebook icon TwitterZip JumpProwindPudaPvT CapitalQ Cells SE

  18. Temperature dependent band offsets in PbSe/PbEuSe quantum well heterostructures

    SciTech Connect (OSTI)

    Simma, M.; Bauer, G.; Springholz, G. [Institut fuer Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet, A-4040 Linz (Austria)

    2012-10-22T23:59:59.000Z

    The band offsets of PbSe/Pb{sub 1-x}Eu{sub x}Se multi-quantum wells grown by molecular beam epitaxy are determined as a function of temperature and europium content using temperature-modulated differential transmission spectroscopy. The confined quantum well states in the valence and conduction bands are analyzed using a k{center_dot}p model with envelope function approximation. From the fit of the experimental data, the normalized conduction band offset is determined as 0.45{+-}0.15 of the band gap difference, independently of Eu content up to 14% and temperature from 20 to 300 K.

  19. Reaction kinetics of a-CuInSe2 formation from an In2Se3/CuSe bilayer precursor film

    E-Print Network [OSTI]

    Anderson, Timothy J.

    with Ga or S are proven absorber materials for high efficiency thin film solar cells. Interestingly CIGS system using the stacked elemental film precursors (e.g. glass/Cu/In/Se, glass/Cu/Se, glass

  20. Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals

    SciTech Connect (OSTI)

    Tripathi, S.K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India); Sharma, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India)

    2013-05-15T23:59:59.000Z

    Highlights: ? Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ? From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ? Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ? The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

  1. Cotinga Alirrufa La Cotinga Alirrufa se distribuye en

    E-Print Network [OSTI]

    Cuervo, Andrés

    . inventarios y su estudio, la situación actual de esta especie en Colombia. Se considera casi Aphanotriccus

  2. 31P Solid State NMR Studies of Metal Selenophosphates Containing [P2Se6]4-, [P4Se10]4-, [PSe4]3-, [P2Se7]4-, and [P2Se9]4-Ligands

    E-Print Network [OSTI]

    Weliky, David

    31P Solid State NMR Studies of Metal Selenophosphates Containing [P2Se6]4-, [P4Se10]4-, [PSe4]3-, [P2Se7]4-, and [P2Se9]4- Ligands Christian G. Canlas, Mercouri G. Kanatzidis, and David P. Weliky P solid-state nuclear magnetic resonance (NMR) spectra of 12 metal-containing selenophosphates have

  3. Fluorescence relaxation dynamics of CdSe and CdSe/CdS core/shell quantum dots

    SciTech Connect (OSTI)

    Kaur, Gurvir; Kaur, Harmandeep [Centre of Advanced Study in Physics, Department of Physics, Panjab University, Chandigarh-160014 (India); Tripathi, S. K., E-mail: surya@pu.ac.in [Centre of Advanced Study in Physics, Panjab University, Chandigarh- 160014 (India)

    2014-04-24T23:59:59.000Z

    Time-resolved fluorescence spectra for colloidal CdSe and CdSe/CdS core/shell quantum dots have been investigated to know their electron relaxation dynamics at the maximum steady state fluorescence intensity. CdSe core and CdSe/CdS type I core-shell materials with different shell (CdS) thicknesses have been synthesized using mercaptoacetic acid as a capping agent. Steady state absorption and emission studies confirmed successful synthesis of CdSe and CdSe/CdS core-shell quantum dots. The fluorescence shows a tri-exponential decay with lifetimes 57.39, 7.82 and 0.96 ns for CdSe quantum dots. The lifetime of each recombination decreased with growth of CdS shell over the CdSe core, with maximum contribution to fluorescence by the fastest transition.

  4. Twinning effect on photoluminescence spectra of ZnSe nanowires

    SciTech Connect (OSTI)

    Xu, Jing; Wang, Chunrui, E-mail: crwang@dhu.edu.cn; Wu, Binhe; Xu, Xiaofeng [Department of Applied Physics and State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 Renmin Rd. North, Songjiang District, Shanghai 201620 (China); Chen, Xiaoshuang [Department of Applied Physics and State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 Renmin Rd. North, Songjiang District, Shanghai 201620 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 200083 (China); Oh, Hongseok; Baek, Hyeonjun; Yi, Gyu-Chul [Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-747 (Korea, Republic of)

    2014-11-07T23:59:59.000Z

    Bandgap engineering in a single material along the axial length of nanowires may be realized by arranging periodic twinning, whose twin plane is vertical to the axial length of nanowires. In this paper, we report the effect of twin on photoluminescence of ZnSe nanowires, which refers to the bandgap of it. The exciton-related emission peaks of transverse twinning ZnSe nanowires manifest a 10-meV-blue-shift in comparison with those of longitudinal twinning ZnSe nanowires. The blue-shift is attributed to quantum confinement effect, which is influenced severely by the proportion of wurtzite ZnSe layers in ZnSe nanowires.

  5. Spectral photoresponse of ZnSe/GaAs(001) heterostructures with CdSe ultra-thin quantum well insertions

    SciTech Connect (OSTI)

    Valverde-Chávez, D. A.; Sutara, F.; Hernández-Calderón, I. [Physics Department, Cinvestav-IPN, Av. IPN 2508, 07360 México, DF (Mexico)

    2014-05-15T23:59:59.000Z

    We present a study of the spectral photoresponse (SPR) of ZnSe/GaAs(001) heterostructures for different ZnSe film thickness with and without CdSe ultra-thin quantum well (UTQW) insertions. We observe a significant increase of the SPR of heterostructures containing 3 monolayer thick CdSe UTQW insertions; these results encourage their use in photodetectors and solar cells.

  6. Thermoelectric transport of Se-rich Ag{sub 2}Se in normal phases and phase transitions

    SciTech Connect (OSTI)

    Mi, Wenlong; Lv, Yanhong [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences,1295 Dingxi Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Qiu, Pengfei; Shi, Xun, E-mail: xshi@mail.sic.ac.cn, E-mail: cld@mail.sic.ac.cn; Chen, Lidong, E-mail: xshi@mail.sic.ac.cn, E-mail: cld@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences,1295 Dingxi Road, Shanghai 200050 (China); Zhang, Tiansong [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences,1295 Dingxi Road, Shanghai 200050 (China)

    2014-03-31T23:59:59.000Z

    Small amount of Se atoms are used to tune the carrier concentrations (n{sub H}) and electrical transport in Ag{sub 2}Se. Significant enhancements in power factor and thermoelectric figure of merit (zT) are observed in the compositions of Ag{sub 2}Se{sub 1.06} and Ag{sub 2}Se{sub 1.08}. The excessive Se atoms do not change the intrinsically electron-conducting character in Ag{sub 2}Se. The detailed analysis reveals the experiment optimum carrier concentration in Ag{sub 2}Se is around 5?×?10{sup 18}?cm{sup ?3}. We also investigate the temperature of maximum zT and the thermoelectric transport during the first order phase transitions using the recently developed measurement system.

  7. Glass formation and the third harmonic generation of Cu{sub 2}Se–GeSe{sub 2}–As{sub 2}Se{sub 3} glasses

    SciTech Connect (OSTI)

    Reshak, A. H., E-mail: maalidph@yahoo.co.uk [New Technologies-Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Klymovych, O. S.; Zmiy, O. F. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, Voli Av. 13, 43025 Lutsk (Ukraine); Myronchuk, G. L.; Zamuruyeva, O. V. [Department of Physics, Lesya Ukrainka Eastern European National University, Voli Av. 13, 43025 Lutsk (Ukraine); Alahmed, Z. A. [Department of Physics and Astronomy, King Saud University, Riyadh 11451 (Saudi Arabia); Chyský, J.; Bila, Jiri [Department of Instrumentation and Control Engineering, Faculty of Mechanical Engineering, CTU in Prague, Technicka 4, 166 07 Prague 6 (Czech Republic); Kamarudin, H. [Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia)

    2014-10-14T23:59:59.000Z

    We have performed the investigation of the nonlinear optical properties namely the third harmonic generation (THG) of the glass-formation region in the Cu{sub 2}Se–GeSe{sub 2}–As{sub 2}Se{sub 3} system. The samples were synthesized by direct single-temperature method from high-purity elementary substances. We have found that the value of disorder parameter ? depends on the composition of the glassy alloys. The measurements show that increasing the Cu{sub 2}Se concentration leads to increased slope of the absorption edge, which may be explained by the decrease of the height of random potential relief for the electrons in the tails of the state density which border the band edges. A very sharp increase in the THG at low temperature was observed. Significant enhancement in THG was obtained with decreasing the energy gap, which agreed well with the nonlinear optical susceptibilities obtained from other glasses.

  8. ammassalik island se: Topics by E-print Network

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

    Park Headquarters, Ventu- ra County, California. Conlee, Christina A 2000-01-01 26 infantil no se denuncia Multidisciplinary Databases and Resources Websites Summary:...

  9. Workshop on Revisions to SE 2004 Mark Ardis David Budgen

    E-Print Network [OSTI]

    Ardis, Mark

    Workshop on Revisions to SE 2004 Mark Ardis David Budgen Stevens Institute of Technology University-day workshop on needed revisions to Software Engineering 2004: Curriculum Guidelines for Undergraduate Degree Programs in Software Engineering (SE 2004). A brief overview of the current guidelines and their revision

  10. HA133F10SE1558 Final Report

    E-Print Network [OSTI]

    HA133F10SE1558 Final Report Trainable Video Analytic Software (HA133F10SE1558) October 20, 2010.4 Machine / Human Concepts 9 4.0 SeaUrchin Data 10 4.1 Halibut Detection Performance 12 4.1.1 Understanding) investigated the use of machine vision technology applied to electronic monitoring of the Rockfish fishery

  11. p1 RJM 07/01/14 SE3SE11 -Sustainable Electrical Energy -Gaia Dr Richard Mitchell 2014

    E-Print Network [OSTI]

    Mitchell, Richard

    p1 RJM 07/01/14 SE3SE11 - Sustainable Electrical Energy - Gaia © Dr Richard Mitchell 2014 1 : Sustainable Electrical Energy - Gaia This module considers the sustainable aspects of Electrical Energy For instance, various colleagues, including Dr George Whitfield, researched photovoltaic solar systems

  12. Optical Probing of metamagnetic phases in epitaxial EuSe

    SciTech Connect (OSTI)

    Galgano, G. D.; Henriques, A. B. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil); Bauer, G.; Springholz, G. [Institut fuer Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet Linz, 4040 Linz (Austria)

    2011-12-23T23:59:59.000Z

    EuSe is a wide gap magnetic semiconductors with a potential for applications in proof-of-concept spintronic devices. When the temperature is lowered, EuSe goes through sharp transitions between a variety of magnetic phases and is thus described as metamagnetic. The purpose of the present investigation is to correlate the magnetic order to the sharp dichroic doublet, discovered recently in high quality thin epitaxial layers of EuSe, grown by molecular beam epitaxy. We report detailed measurements of the doublet positions and intensities as a function of magnetic field in low temperatures, covering several magnetic phases.

  13. Hot exciton transport in ZnSe quantum wells

    E-Print Network [OSTI]

    Zhao, Hui; Moehl, Sebastian; Wachter, Sven; Kalt, Heinz

    2002-02-01T23:59:59.000Z

    The in-plane transport of excitons in ZnSe quantum wells is investigated directly by microphotoluminescence in combination with a solid immersion lens. Due to the strong Froehlich coupling, the initial kinetic energy of the excitons is well...

  14. Campus Security Report 1 Campus seCurity

    E-Print Network [OSTI]

    Wilmers, Chris

    Campus Security Report 1 Campus seCurity and Fire saFety report UC Santa Cruz 2010 #12;Campus Security Report 2 UC Santa Cruz Geography ........................................................ 8 Security and Access to Campus Buildings and Grounds ........................................ 8

  15. Inkrafttreten Diese Ordnung tritt mit Genehmigung durch die Se-

    E-Print Network [OSTI]

    Hoffmeister, Thomas S.

    § 7 Inkrafttreten Diese Ordnung tritt mit Genehmigung durch die Se- natorin für Bildung und. Artikel 2 Die �nderung tritt nach der Genehmigung des Rek- tors mit Wirkung vom 1. Oktober 2007 in Kraft

  16. Quantum size effects and transport phenomena in PbSe quantum wells and PbSe/EuS superlattices

    SciTech Connect (OSTI)

    Rogacheva, E. I.; Nashchekina, O. N.; Ol'khovskaya, S. I.; Sipatov, A. Yu. [National technical university Kharkov polytechnic institute, 21 Frunze St., Kharkov, 61002 (Ukraine); Dresselhaus, M. S. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (United States)

    2013-12-04T23:59:59.000Z

    It is established that the room-temperature dependences of transport properties on the total thickness of PbSe layers d in PbSe/EuS superlattices exhibit an oscillatory behavior. It is shown that the oscillation period ?d practically coincides with the period of the thickness oscillations observed earlier in single PbSe/EuS quantum well. The non-monotonic character of these dependences is attributed to quantum size effects. The theoretically estimated and experimentally determined ?d values are in good agreement.

  17. MINIREVIEW / MINISYNTHE` SE The role of chromatin structure in regulating

    E-Print Network [OSTI]

    Krebs, Jocelyn E.

    within many stress-induced promoters, such as stress re- sponse elements and heat shock elements, allow. Key words: chromatin, transcription, stress response, heat shock. Re´sume´ : Toutes les cellules, quMINIREVIEW / MINISYNTHE` SE The role of chromatin structure in regulating stress

  18. se de doctorat en informatique Comprendre le Web cach

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    niveau à l'aide de telles descriptions. Abstract e hidden Web (also known as deep or invisible Web'informations, complexité Keywords: hidden Web, deep Web, databases, information extraction, complexity tel-00198150,versionèse de doctorat en informatique Comprendre le Web caché Understanding the Hidden Web Pierre

  19. EXTERIOR POWERS OF SYMMETRIC BILINEAR FORMS SE'AN MCGARRAGHY

    E-Print Network [OSTI]

    -fold exterior power of V . Then the ring of* * isomorphism classes of finite-dimensional K-vector spaces under]. 3. Exterior and symmetric powers of symmetric bilinear forms Let V be a vector space of dimension EXTERIOR POWERS OF SYMMETRIC BILINEAR FORMS SE

  20. SeRLoc: Robust Localization for Wireless Sensor Networks

    E-Print Network [OSTI]

    Hochberg, Michael

    SeRLoc: Robust Localization for Wireless Sensor Networks LOUKAS LAZOS and RADHA POOVENDRAN University of Washington Many distributed monitoring applications of Wireless Sensor Networks (WSNs) require of Wireless Sensor Networks to determine their location in an untrusted environment, known as the secure

  1. Structural Changes in Vitreous GeSe4 under Pressure

    SciTech Connect (OSTI)

    Skinner L. B.; Parise J.; Benmore, C.J,; Antao, S.; Soignard, E.; Amin, S.A.; Bychkov, E.; Rissi, E. and Yarger, J.L.

    2011-11-21T23:59:59.000Z

    High-energy X-ray diffraction experiments have been performed on GeSe{sub 4} glass up to pressures of 8.6 GPa, and the equation of state has been measured up to 10 GPa. The X-ray structure factors reveal a decrease in the first sharp diffraction peak intensity and broadening with pressure, which signifies a break-up of the intermediate range order in the glass. In contrast, the principal peak in the structure factor shows an increase in intensity and a sharpening with pressure, which is attributed to an increase in extended range order and coherence of the compacted units. The average nearest neighbor coordination number is found to remain constant in GeSe{sub 4} glass (within experimental error) over the pressure range measured. This is in contrast with the gradual increase found in GeSe{sub 2} glass. Rather, in GeSe{sub 4} glass the densification mechanism is shown to be associated with large inward shifts of the second neighbor and higher coordination shells. These features appear as additional correlations at 3.3 and 5.3 {angstrom} in the differences taken between adjacent pair distribution functions with increasing pressure.

  2. con Diabetes Su diabetes s se puede controlar!

    E-Print Network [OSTI]

    Do Well, Be Well con Diabetes ¡Su diabetes sí se puede controlar! Educational programs of the Texas, and the County Commissioners Courts of Texas Cooperating. to develop diabetes self-care skills, to improve eating habits and maintain good nutrition, to increase physical activity, to prevent diabetes complications

  3. KTH Aeronautical and Vehicle Engineering, Teknikringen 8, SE-10044 Stockholm. Phone: +46 70 6522441. E-mail: mabe@kth.se Pg: 1 56 53-9. Bg: 895-9223. VAT: SE202100305401. www.kth.se

    E-Print Network [OSTI]

    Haviland, David

    KTH Aeronautical and Vehicle Engineering, Teknikringen 8, SE-10044 Stockholm. Phone: +46 70 6522441 on Energy Usage of Tracked Taxis Car-like vehicles running on elevated guideways in urban areas or airports vehicles and traditional vehicles, including both measurements and simulations. - Study the rolling

  4. Postal address P.O. Box 118, SE-221 00 LUND Visiting address John Ericssons vg 3 Telephone switchboard +46 46-222 00 00 E-mail outgoing@kansli.lth.se Internet http://www.lth.se

    E-Print Network [OSTI]

    switchboard +46 46-222 00 00 E-mail outgoing@kansli.lth.se Internet http://www.lth.se International Office Telephone switchboard +46 46-222 00 00 E-mail outgoing@kansli.lth.se Internet http://www.lth.se ARGENTINA Sciences (Lahti Yrkeshögskola) Oulun yliopisto Tampereen Teknillinen Korkeakoulu University of Lapland

  5. Reverse Monte Carlo simulation of Se{sub 80}Te{sub 20} and Se{sub 80}Te{sub 15}Sb{sub 5} glasses

    SciTech Connect (OSTI)

    Abdel-Baset, A. M.; Rashad, M. [Physics Department, Faculty of Science , Assiut University, Assiut, P.O. Box 71516 (Egypt); Moharram, A. H. [Faculty of Science, King Abdul Aziz Univ., Rabigh Branch, P.O. Box 433 (Saudi Arabia)

    2013-12-16T23:59:59.000Z

    Two-dimensional Monte Carlo of the total pair distribution functions g(r) is determined for Se{sub 80}Te{sub 20} and Se{sub 80}Te{sub 15}Sb{sub 5} alloys, and then it used to assemble the three-dimensional atomic configurations using the reverse Monte Carlo simulation. The partial pair distribution functions g{sub ij}(r) indicate that the basic structure unit in the Se{sub 80}Te{sub 15}Sb{sub 5} glass is di-antimony tri-selenide units connected together through Se-Se and Se-Te chain. The structure of Se{sub 80}Te{sub 20} alloys is a chain of Se-Te and Se-Se in addition to some rings of Se atoms.

  6. APS/DPP 111207-se 1 University Fusion Association Meeting

    E-Print Network [OSTI]

    University Funding FY 2007-2008 ($ Millions) Program Element FY 2007 FY 2008 Sept Plan Oct Plan · C.0 · HEDLP 1.8 1.9 · Intl, Diagnostics, HBCU, Other 4.3 4.8 · Total University Funding 76.8 78.1 #12;APSAPS/DPP 111207-se 1 University Fusion Association Meeting Orlando, FL November 12, 2007 Stephen

  7. Bi-Se doped with Cu, p-type semiconductor

    DOE Patents [OSTI]

    Bhattacharya, Raghu Nath; Phok, Sovannary; Parilla, Philip Anthony

    2013-08-20T23:59:59.000Z

    A Bi--Se doped with Cu, p-type semiconductor, preferably used as an absorber material in a photovoltaic device. Preferably the semiconductor has at least 20 molar percent Cu. In a preferred embodiment, the semiconductor comprises at least 28 molar percent of Cu. In one embodiment, the semiconductor comprises a molar percentage of Cu and Bi whereby the molar percentage of Cu divided by the molar percentage of Bi is greater than 1.2. In a preferred embodiment, the semiconductor is manufactured as a thin film having a thickness less than 600 nm.

  8. Sanden Vendo America: Proposed Penalty (2014-SE-52002) | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin ofEnergy atLLC - FE DKT. 10-160-LNG -Energy Proposed Penalty (2014-SE-52002)

  9. al publico sobre: Topics by E-print Network

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

    de Argentina, Cuba, Colombia, Chile (exilio), EE.UU., Guatemala, Uruguay (exilio) y Venezuela. De todos los temas tratados, se enfatizo principalmente la "Profesionalizacin en...

  10. al faenamiento sobre: Topics by E-print Network

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

    de Argentina, Cuba, Colombia, Chile (exilio), EE.UU., Guatemala, Uruguay (exilio) y Venezuela. De todos los temas tratados, se enfatizo principalmente la "Profesionalizacin en...

  11. al destete sobre: Topics by E-print Network

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

    de Argentina, Cuba, Colombia, Chile (exilio), EE.UU., Guatemala, Uruguay (exilio) y Venezuela. De todos los temas tratados, se enfatizo principalmente la "Profesionalizacin en...

  12. Structure, nonlinear properties, and photosensitivity of (GeSe2)100-x(Sb2Se3)x glasses

    E-Print Network [OSTI]

    -Anne, J. Charrier, J.-P. Guin, and A. Moréac, "Sputtering and pulsed laser deposition for near- and mid-infrared to increase the n2 from 2 to 710-18 m2 /W for As2S3 glass to 11-3010-18 m2 /W for As2Se3 glass at near-infrared measurements were performed with 10 mg powdered samples, heated up to 450°C at heating rate of 10 °C.min-1

  13. Fluorescence quenching of CdSe quantum dots on graphene

    SciTech Connect (OSTI)

    Guo, Xi Tao; Hua Ni, Zhen, E-mail: zhni@seu.edu.cn; Yan Nan, Hai; Hui Wang, Wen [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China)] [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China); Yan Liao, Chun [Physics Department, National Photoelectric Technology and Functional Materials and Application of Science and Technology International Cooperation Base, Northwest University, Xi'an 710069 (China)] [Physics Department, National Photoelectric Technology and Functional Materials and Application of Science and Technology International Cooperation Base, Northwest University, Xi'an 710069 (China); Zhang, Yan; Wei Zhao, Wei [Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China)] [Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China)

    2013-11-11T23:59:59.000Z

    We studied systematically the fluorescence quenching of CdSe quantum dots (QDs) on graphene and its multilayers, as well as graphene oxide (GO) and reduced graphene oxide (rGO). Raman intensity of QDs was used as a quantitatively measurement of its concentration in order to achieve a reliable quenching factor (QF). It was found that the QF of graphene (?13.1) and its multilayers is much larger than rGO (?4.4), while GO (?1.5) has the lowest quenching efficiency, which suggests that the graphitic structure is an important factor for quenching the fluorescence of QDs. It was also revealed that the QF of graphene is not strongly dependent on its thicknesses.

  14. Effect of selenium deficiency on the thermoelectric properties of n-type In4Se3-x [In subscript 4 Se subscript 3-x] compounds

    E-Print Network [OSTI]

    Zhu, G. H.

    Thermoelectric properties of dense bulk polycrystalline In4Se3?x [In subscript 4 Se subscript 3-x] (x = 0, 0.25, 0.5, 0.65, and 0.8) compounds

  15. MoSe2 thin films synthesized by solid state reactions between Mo and Se J. Pouzet (1) and J. C. Bernede (2)

    E-Print Network [OSTI]

    Boyer, Edmond

    807 MoSe2 thin films synthesized by solid state reactions between Mo and Se thin films J. Pouzet (1 reaction, induced by annealing, between the Mo and Se constituents in thin films form. The films have been thin films annealed under selenium pressure at only 770 K are well crystallized. The electrical

  16. VIGILANTE: Violence and Security in Postwar Guatemala

    E-Print Network [OSTI]

    Sharp, Ellen Jane

    2014-01-01T23:59:59.000Z

    involves seeing all forms of violence as connected andimportance of seeing all forms of violence on a continuum

  17. LAS HORMIGAS (HYMENOPTERA: FORMICIDAE) DE GUATEMALA

    E-Print Network [OSTI]

    Schultz, Ted

    hormigas, a partir de publicacio- nes taxonómicas recientes e inventarios intensivos del proyec- to LLAMA

  18. 24 Guatemala 1 1 COLLEGES (STUDENTS)

    E-Print Network [OSTI]

    Collins, Gary S.

    Costa Rica 3 46 Malaysia 7 80 United Arab Emirates 2 13 Cyprus 1 47 Mauritania 1 81 United Kingdom 13 14

  19. VIGILANTE: Violence and Security in Postwar Guatemala

    E-Print Network [OSTI]

    Sharp, Ellen Jane

    2014-01-01T23:59:59.000Z

    225–246. New York: Routledge. Graeber, David 2011 Debt: TheUS healthcare crisis attests (Graeber 2011). The communalover the last forty years (Graeber 2011, Greenhouse 2010,

  20. Photoluminescence study of the substitution of Cd by Zn during the growth by atomic layer epitaxy of alternate CdSe and ZnSe monolayers

    SciTech Connect (OSTI)

    Hernández-Calderón, I. [Physics Department,Cinvestav, Ave. IPN2508, 07360, México City, DF. (Mexico); Salcedo-Reyes, J. C. [Thin Films Group, Physics Department, Pontificia Universidad Javeriana, Cr. 7 No. 43-82, Ed. 53, Lab. 404, Bogotá, D.C. (Colombia)

    2014-05-15T23:59:59.000Z

    We present a study of the substitution of Cd atoms by Zn atoms during the growth of alternate ZnSe and CdSe compound monolayers (ML) by atomic layer epitaxy (ALE) as a function of substrate temperature. Samples contained two quantum wells (QWs), each one made of alternate CdSe and ZnSe monolayers with total thickness of 12 ML but different growth parameters. The QWs were studied by low temperature photoluminescence (PL) spectroscopy. We show that the Cd content of underlying CdSe layers is affected by the exposure of the quantum well film to the Zn flux during the growth of ZnSe monolayers. The amount of Cd of the quantum well film decreases with higher exposures to the Zn flux. A brief discussion about the difficulties to grow the Zn{sub 0.5}Cd{sub 0.5}Se ordered alloy (CuAu-I type) by ALE is presented.

  1. The influence of Se pressure on the electronic properties of CuInSe{sub 2} grown under Cu-excess

    SciTech Connect (OSTI)

    Deprédurand, Valérie; Bertram, Tobias; Regesch, David; Henx, Benjamin; Siebentritt, Susanne [Laboratory for Photovoltaics, Physics and Materials Science Research Unit, University of Luxembourg, L-4422 Belvaux (Luxembourg)

    2014-10-27T23:59:59.000Z

    Standard Cu-poor Cu(In,Ga)Se{sub 2} solar cell absorbers are usually prepared under high Se excess since the electronic properties of the absorbers are better if prepared under high Se pressure. However, in CuInSe{sub 2}, grown under Cu-excess, it was found that solar cell properties improve with lowering the Se pressure, mostly because of reduced tunnel contribution to the recombination path. Lower Se pressure during Cu-rich growth leads to increased (112) texture of the absorber films, to better optical film quality, as seen by increased excitonic luminescence and to lower net doping levels, which explains the reduced tunnelling effect. These findings show an opposite trend from the one observed in Cu-poor Cu(In,Ga)Se{sub 2}.

  2. LISTE ELECTORALE BELFORT Bureau Secrtariat SeT NOM PRENOM DEPARTEMENT ETABLISSEMENT

    E-Print Network [OSTI]

    Jeanjean, Louis

    Serge FEMTO-ST ENERGIE UFC AHMED Fayez-Shakil SeT UTBM AIT ALI Kahina SeT UTBM AIT-CHEIK-BIHI Wafaa SeT UTBM AMRANE Sofiane FEMTO-ST ENERGIE UFC ASENSIO SAUTO Joseba FEMTO-ST ENERGIE UFC ATTIA Dhouha SeT UTBM BAERT Jérôme FEMTO-ST ENERGIE UFC BAKKALI Zouheir FEMTO-ST ENERGIE UTBM BASSO Gillian SeT UTBM

  3. Ann bay lodyans 13 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    apral fe le sa a, papa? Papa: Le sa a, se Pari, se manje nan gran restoran, se bwe chanpay, se bel fanm! Pitit: Men, si boul la pa tonbe, papa? Papa: Le sa a, pitit mwen, se lakay, se kasav, se kleren, se manman ou. 8 PAPIYON AK DEMWAZEL Se te... li pre yon fie jon. Tet li foure nan ke fie a, li t ap bwe lawouze ladann, li t ap souse ti poud jon lan. Ti papiyon an te leje, le a te pi leje pase I. Ti papiyon an t ap bat zel li. L6 li fin bwe jouk tan tet li vire ak tout like I te bwe nan...

  4. Thermal Processing Effects on Microstructure and Composition of Cu3SbSe3

    SciTech Connect (OSTI)

    Majsztrik, Paul W [ORNL; Kirkham, Melanie J [ORNL; Garcia Negron, Valerie [Polytechnic University of Puerto Rico (PUPR); Lara-Curzio, Edgar [ORNL; Skoug, Eric [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing

    2013-01-01T23:59:59.000Z

    We report on the effects of thermal processing on the microstructure and composition of a system with overall stoichiometry of 3Cu:1Sb:3Se with the aim of producing single-phase Cu3SbSe3. It was found that slowly cooling from the melt produced a multiphase material consisting of Cu2Se and CuSbSe2, but devoid of Cu3SbSe3. Cooling rapidly from the melt resulted in three-phase microstructures consisting of Cu2Se, CuSbSe2, and Cu3SbSe3. Subsequent annealing of the three-phase material between 325 C and 400 C shifted composition towards nearly pure Cu3SbSe3, the target compound of this work. The kinetics of the transformation into Cu3SbSe3 is successfully described using a modified Avrami model, which suggests that diffusion is the rate-controlling step. Values of Young s modulus and hardness, obtained by nanoindentation, are reported for Cu2Se, CuSbSe2, and Cu3SbSe3.

  5. ENG ME/EC/SE 701: Optimal and robust control Fall 2011 ENG ME/EC/SE 701: Optimal and Robust Control, Fall 2011

    E-Print Network [OSTI]

    emphases given on the optimal control portion. Under optimal control, topics will include the linear-domain (or classical) control (at the level of ME 404) and linear system theory (at the level of ME 501ENG ME/EC/SE 701: Optimal and robust control Fall 2011 ENG ME/EC/SE 701: Optimal and Robust Control

  6. ENG EC/ME/SE 543 Sustainable Power Systems Page 1/5 ENG EC/ME/SE 543 Sustainable Power Systems: Planning, Operation, and Markets

    E-Print Network [OSTI]

    Lin, Xi

    ENG EC/ME/SE 543 Sustainable Power Systems Page 1/5 Syllabus ENG EC/ME/SE 543 Sustainable Power considers key technical and economic characteristics of power systems and presents their interaction.e., the safeguard of security and stability in today's complex power systems. Course Overview We review the key

  7. ENG EC/ME/SE 543 Sustainable Power Systems Page 1/4 ENG EC/ME/SE 543 Sustainable Power Systems: Planning, Operation, and Markets

    E-Print Network [OSTI]

    ENG EC/ME/SE 543 Sustainable Power Systems Page 1/4 Syllabus ENG EC/ME/SE 543 Sustainable Power of power systems and presents their interaction in the design and operation of markets that foster's complex power systems. Course Overview We review the key characteristics of Electric Power Transmission

  8. ENG EC/ME/SE 543 Sustainable Power Systems Page 1/5 ENG EC/ME/SE 543 Sustainable Power Systems: Planning, Operation, and Markets

    E-Print Network [OSTI]

    ENG EC/ME/SE 543 Sustainable Power Systems Page 1/5 Syllabus ENG EC/ME/SE 543 Sustainable Power. Under this premise, the course considers key technical and economic characteristics of power systems efficiency while allowing for the safeguard of security and stability in today's complex power systems

  9. ENG EC/ME/SE 543 Sustainable Power Systems Page 1/5 ENG EC/ME/SE 543 Sustainable Power Systems: Planning, Operation, and Markets

    E-Print Network [OSTI]

    ENG EC/ME/SE 543 Sustainable Power Systems Page 1/5 Syllabus ENG EC/ME/SE 543 Sustainable Power of power systems and presents their interaction in the design and operation of markets that foster systems. Course Overview We review the key characteristics of Electric Power Transmission and Distribution

  10. Mechanisms of the Wurtzite to Rocksalt Transformation in CdSe Nanocrystals Michael Grunwald,1

    E-Print Network [OSTI]

    Rabani, Eran

    Mechanisms of the Wurtzite to Rocksalt Transformation in CdSe Nanocrystals Michael Gru¨nwald,1 Eran transition from the four-coordinate wurtzite to the six-coordinate rocksalt structure in CdSe nanocrystals wurtzite structure to the six-coordinate rocksalt structure in CdSe is strongly influenced by crystal size

  11. DISSERTATION ANTICIPATED PERFORMANCE OF Cu(In,Ga)Se2 SOLAR CELLS IN THE

    E-Print Network [OSTI]

    Sites, James R.

    i DISSERTATION ANTICIPATED PERFORMANCE OF Cu(In,Ga)Se2 SOLAR CELLS IN THE THIN-FILM LIMIT Submitted ENTITLED `ANTICIPATED PERFORMANCE OF Cu(In,Ga)Se2 SOLAR CELLS IN THE THIN-FILM LIMIT' BE ACCEPTED(In,Ga)Se2 SOLAR CELLS IN THE THIN-FILM LIMIT The demand for alternative sources of energy is rapidly

  12. Cu(In,Ga)Se2based Photovoltaics: Challenges and Opportunities

    E-Print Network [OSTI]

    Firestone, Jeremy

    % Different companies, processes, substrates Substrate Mo Cu(InGa)Se2 buffer TCO Cu(InGa)Se2 Solar Cells #12-evaporation using 3-stage process (ZSW, NREL) Reaction of sputtered precursors (Solar Frontier) From pilot; High optical absorption Unique properties for solar cells Compositional tolerance Cu(InGa)Se2 Thin

  13. DISSERTATION DEVICE PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION DEVICE PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS Submitted by Markus Gloeckler PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS BE ACCEPTED AS FULFILLING IN PART REQUIREMENTS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS Thin-film solar cells have the potential to be an important

  14. Observation and Measurement of Se-79 in SRS High-Level Tank Fission Product Waste

    SciTech Connect (OSTI)

    Dewberry, R.A.

    2000-08-21T23:59:59.000Z

    The authors report the first observation of confirmed Se-79 activity in Savannah River Site high level fission product waste. Se-79 was measured after a seven step chemical treatment to remove interfering activity from Cs-137, Sr-90, and plutonium at levels 105 times higher than the observed Se-79 content and to remove Tc-99 at levels 300 times higher than observed Se-79. Se-79 was measured by liquid scintillation beta-decay counting after specific tests to eliminate uncertainties from possible contributions from Tc-99, Pm-147, Sm-151, Zr-93, or Pu-241, whose beta-decay spectra could appear similar to that of Se-79, and whose content would be expected at levels near or greater than Se-79.

  15. High-Pressure Synthesis and Structure Determination of K6(SeO4)(SeO5), The First Potassium Orthoselenate(VI)

    SciTech Connect (OSTI)

    Orosel,D.; Dinnebeier, R.; Jansen, M.

    2006-01-01T23:59:59.000Z

    The authors report on the first synthesis of a potassium orthoselenate(VI), K{sub 6}(SeO{sub 4})(SeO{sub 5}), and the structure determination from synchrotron powder diffraction data. The title compound crystallizes in the tetragonal space group P4{sub 1}2{sub 1}2 with a = 8.1259(1) {angstrom}, c = 17.4953(2) {angstrom}, V = 1155.21(2) {angstrom}{sup 3}, and Z = 4. Selenium displays two different complex anions, tetrahedral SeO{sub 4}{sup 2-} and trigonal-bipyramidal SeO{sub 5}{sup 4-}. When the formula is reduced to A{sub 3}B, the spatial arrangement of the constituting building units can be derived from the Li{sub 3}Bi type of structure.

  16. ADVANCES IN SE-79 ANALYSES ON SAVANNAH RIVER SITE RADIOACTIVE WASTE MATRICES

    SciTech Connect (OSTI)

    Diprete, D; C Diprete, C; Ned Bibler, N; Cj Bannochie, C; Michael Hay, M

    2009-03-16T23:59:59.000Z

    Waste cleanup efforts underway at the United States Department of Energy's (DOE) Savannah River Site (SRS) in South Carolina, as well as other DOE nuclear sites, have created a need to characterize {sup 79}Se in radioactive waste inventories. Successful analysis of {sup 79}Se in high activity waste matrices is challenging for a variety of reasons. As a result of these unique challenges, the successful quantification of {sup 79}Se in the types of matrices present at SRS requires an extremely efficient and selective separation of {sup 79}Se from high levels of interfering radionuclides. A robust {sup 79}Se radiochemical separation method has been developed at the Savannah River National Laboratory (SRNL) which is routinely capable of successfully purifying {sup 79}Se from a wide range of interfering radioactive species. In addition to a dramatic improvements in the Kd, ease, and reproducibility of the analysis, the laboratory time has been reduced from several days to only 6 hours.

  17. Photovoltaic Devices Employing Ternary PbSxSe1-x Nanocrystals

    SciTech Connect (OSTI)

    Ma, Wanli; Luther, Joseph; Zheng, Haimei; Wu, Yue; Alivisatos, A. Paul

    2009-02-05T23:59:59.000Z

    We report solar cells based on highly confined nanocrystals of the ternary compound PbSxSe1-x. Crystalline, monodisperse alloyed nanocrystals are obtained using a one-pot, hot injection reaction. Rutherford back scattering and energy filtered transmission electron microscopy suggest that the S and Se anions are uniformly distributed in the alloy nanoparticles. Photovoltaic devices made using ternary nanoparticles are more efficient than either pure PbS or pure PbSe based nanocrystal devices.

  18. Pressure-induced phase transformation of In2Se3 Anya M. Rasmussen,1

    E-Print Network [OSTI]

    McCluskey, Matthew

    13 February 2013) In2Se3 has potential as a phase-change material for memory applications and the defect wurtzite c phase.1 Recently, In2Se3 has received attention as a phase-change material that could be used in phase-change random access memory (PRAM) applications.2,3 In2Se3 may be preferable over Ge2Sb2

  19. Synthesis and Crystal Structure Study of 2’-Se-Adenosine-Derivatized DNA

    SciTech Connect (OSTI)

    Sheng, J.; Salon, J; Gan, J; Huang, Z

    2010-01-01T23:59:59.000Z

    The selenium derivatization of nucleic acids is a novel and promising strategy for 3D structure determination of nucleic acids. Selenium can serve as an excellent anomalous scattering center to solve the phase problem, which is one of the two major bottlenecks in macromolecule X-ray crystallography. The other major bottleneck is crystallization. It has been demonstrated that the incorporated selenium functionality at the 2'-positions of the nucleosides and nucleotides is stable and does not cause significant structure perturbation. Furthermore, it was observed that the 2'-Se-derivatization could facilitate crystallization of oligonucleotides with fast crystal growth and high diffraction quality. Herein, we describe a convenient synthesis of the 2'-Se-adenosine phosphoramidite, and report the first synthesis and X-ray crystal structure determination of the DNA containing the 2'-Se-A derivatization. The 3D structure of 2'-Se-A-DNA decamer [5'-GTACGCGT(2'-Se-A)C-3']{sub 2} was determined at 1.75 {angstrom} resolution, the 2'-Se-functionality points to the minor groove, and the Se-modified and native structures are virtually identical. Moreover, we have observed that the 2'-Se-A modification can greatly facilitate the crystal growth with high diffraction quality. In conjunction with the crystallization facilitation by the 2'-Se-U and 2'-Se-T, this novel observation on the 2'-Se-A functionality suggests that the 2'-Se moiety is sole responsible for the crystallization facilitation and the identity of nucleobases does not influence the crystal growth significantly.

  20. SciTech Connect: A Solution for Solution-Produced [beta]-FeSe...

    Office of Scientific and Technical Information (OSTI)

    A Solution for Solution-Produced beta-FeSe: Elucidating and Overcoming Factors that Prevent Superconductivity Citation Details In-Document Search Title: A Solution for...

  1. Photovoltaic Devices Employing Ternary PbSxSe1-x Nanocrystals

    E-Print Network [OSTI]

    Alivisatos, A. Paul

    2009-01-01T23:59:59.000Z

    performance. The x-axis represents composition change from pure PbSe, to pure PbS, versus various photovoltaic

  2. Photovoltaic performance of ultra-small PbSe quantum dots

    E-Print Network [OSTI]

    Ma, Wanli

    2014-01-01T23:59:59.000Z

    Photovoltaic performance of ultra-small PbSe quantum dotssize on the photovoltaic performance of simple Schottky-typeconfinement on the photovoltaic performance, we adopted

  3. Electrical Transport of Topological Insulator-Bi2Se3 and Thermoelectric Properties of Graphene

    E-Print Network [OSTI]

    WEI, PENG

    2011-01-01T23:59:59.000Z

    tapes are detached to exfoliate the crystal into thinnercan also be utilized to exfoliate Bi 2 Se 3 on top of SrTiO

  4. Photovoltaic Devices Employing Ternary PbSxSe1-x Nanocrystals

    E-Print Network [OSTI]

    Alivisatos, A. Paul

    2009-01-01T23:59:59.000Z

    Photovoltaic Devices Employing Ternary PbS x Se 1-xalloy nanoparticles. Photovoltaic devices made using ternaryInformation for Efficient Photovoltaic Devices Employing

  5. Photovoltaic performance of ultra-small PbSe quantum dots

    E-Print Network [OSTI]

    Ma, Wanli

    2014-01-01T23:59:59.000Z

    Y; Alivisatos, AP, Photovoltaic Devices Employing TernaryPhotovoltaic performance of ultra-small PbSe quantum dotsquantum dot, solar cell, photovoltaic, quantum size effect

  6. Phase diagram of the CulnSe{sub 2}-CuGaSe{sub 2} pseudobinary system studied by combined ab initio density functional theory and thermodynamic calculation

    SciTech Connect (OSTI)

    Xue, H. T.; Tang, F. L., E-mail: tfl03@mails.tsinghua.edu.cn [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Department of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China); Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Lu, W. J.; Li, X. K.; Zhang, Y. [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Department of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China); Feng, Y. D. [Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China)

    2014-08-07T23:59:59.000Z

    The phase diagram of the CuInSe{sub 2}-CuGaSe{sub 2} pseudobinary system was determined using a combination of special quasirandom structure approach, ab initio density functional theory calculations, and thermodynamic modelling. It is shown that the CuIn{sub 1?x}Ga{sub x}Se{sub 2} solution phase has a tendency to phase separation at low temperature. The calculated consolute temperature is 485?K. It is found that both the binodal and spinodal curves are significantly asymmetric and on both curves there are a local maximum and a local minimum, which have not been reported in the previous studies. Our phase diagram can well explain the finding that the inhomogeneity of CuIn{sub 0.25}Ga{sub 0.75}Se{sub 2} is higher than that of CuIn{sub 0.75}Ga{sub 0.25}Se{sub 2} at the same temperature, while the previous phase diagrams cannot. Hence, our phase diagram should be more reliable and applicable.

  7. Fe3O4-LiMo3Se3 Nanoparticle Clusters as Superparamagnetic Nanocompasses

    E-Print Network [OSTI]

    Osterloh, Frank

    -iodopropionic acid treated LiMo3Se3 nanowire bundles with oleic acid-stabilized Fe3O4 nanoparticles of 2.8, 5Fe3O4-LiMo3Se3 Nanoparticle Clusters as Superparamagnetic Nanocompasses Frank E. Osterloh,*, Hiroki A scaleable chemical approach to functional nanoscale analogues of the magnetic compasses in magnetotactic

  8. Photovoltaic cells fabricated by electrophoretic deposition of CdSe nanocrystals

    E-Print Network [OSTI]

    Smith, Nathanael J.

    Photovoltaic cells fabricated by electrophoretic deposition of CdSe nanocrystals Nathanael J. Smith Electrophoretic deposition was used to deposit CdSe nanocrystals on TiO2 for use in photovoltaic cells formed. A solar cell constructed using electrophoretic deposition exhibited a photovoltaic response from

  9. Testing models for the Messinian salinity crisis: The Messinian record in Almera, SE Spain

    E-Print Network [OSTI]

    Riding, Robert

    Testing models for the Messinian salinity crisis: The Messinian record in Almería, SE Spain Juan C Fuentenueva s.n., Universidad de Granada, 18002 Granada, Spain b School of Earth, Ocean and Planetary Sciences, SE Spain, display excellent exposures of Messinian (Late Miocene) sequences. The Sorbas, Almería

  10. Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation

    E-Print Network [OSTI]

    New Mexico, University of

    Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation Nathan J. Withers are reported. Optical degradation is evaluated by tracking the dependence of photoluminescence intensity on irradiation dose. CdSe/ZnS quantum dots show poor radiation hardness, and severely degrade after less than 20

  11. Ultrathin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force

    E-Print Network [OSTI]

    Cui, Yi

    Ultrathin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force Microscopy Seung Sae, Stanford University, Stanford, California 94305 ABSTRACT Ultrathin topological insulator nanostructures), the layered bismuth selenide (Bi2Se3), a single Dirac-cone topological insulator with a large bulk gap, can

  12. Development of a Low Cost Insulated Foil Substrate for Cu(InGaSe)2 Photovoltaics

    SciTech Connect (OSTI)

    ERTEN ESER

    2012-01-22T23:59:59.000Z

    The project validated the use of stainless steel flexible substrate coated with silicone-based resin dielectric, developed by Dow Corning Corporation, for Cu(InGa)Se2 based photovoltaics. The projects driving force was the high performance of Cu(InGa)Se2 based photovoltaics coupled with potential cost reduction that could be achieved with dielectric coated SS web substrate.

  13. Thermoelectric Properties of p-Type PbSe Nanowires Wenjie Liang1,3

    E-Print Network [OSTI]

    Yang, Peidong

    Thermoelectric Properties of p-Type PbSe Nanowires Wenjie Liang1,3 , Oded Rabin1,4 , Allon I-009-9039-2 Research Article Address correspondence to p_yang@berkeley.edu ABSTRACT The thermoelectric properties to 300 K. Thermal annealing of the PbSe nanowires allowed their thermoelectric properties

  14. CdSe Nanocrystals using the Oleic Acid Synthesis Nathanael J. Smith, Fall 2008

    E-Print Network [OSTI]

    Smith, Nathanael J.

    #12;4 M Se in TPB Take 15 g of Se powder in an appropriately sized glass bottle (it must hold at least the lid on the bottle to stop the TBP from evaporating). Perodically give the contents of the bottle

  15. Charge transport in mixed CdSe and CdTe colloidal nanocrystal films

    E-Print Network [OSTI]

    Bawendi, Moungi G.

    We report the influence of trap states on charge transport through films of mixed CdTe and CdSe nanocrystals (NCs) between lateral electrodes, through layered films of CdTe and CdSe NCs in a layered geometry, and through ...

  16. Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3

    E-Print Network [OSTI]

    Shen, Guoyin

    Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3 P. P. Kong1 , F. Sun1,3 , L. Y induce Sb2Se3 into a topological nontrivial state. Here, we report on the discovery of superconductivity superconductive at high pressures above 10 GPa proceeded by a pressure induced insulator to metal like transition

  17. Phase equilibria in the quasi-ternary system Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} and physical properties of (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} single crystals

    SciTech Connect (OSTI)

    Ivashchenko, I.A., E-mail: inna.ivashchenko@mail.ru [Department of Inorganic and Physical Chemistry, Eastern European National University, Voli Ave 13, Lutsk 43025 (Ukraine); Danyliuk, I.V.; Olekseyuk, I.D. [Department of Inorganic and Physical Chemistry, Eastern European National University, Voli Ave 13, Lutsk 43025 (Ukraine); Halyan, V.V. [Department of General Physics, Eastern European National University, Voli Ave 13, Lutsk 43025 (Ukraine)

    2014-02-15T23:59:59.000Z

    The quasi-ternary system Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} was investigated by differential thermal, X-ray phase, X-ray structure, microstructure analysis and microhardness measurements. Five quasi-binary phase diagrams, six polythermal sections, isothermal section at 820 K and the liquidus surface projection were constructed. The character and temperature of the invariant processes were determined. The specific resistance of the single crystals (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} was measured, 7.5×10{sup 5} and 3.15×10{sup 5} ? m, respectively, optical absorption spectra in the 600–1050 nm range were recorded at room temperature, and the band gap energy was estimated which is 1.95±0. 01 eV for both samples. - Graphical abstract: The article reports for the first time the investigated liquidus surface projection of the Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system and isothermal section at 820 K of the system. Five phase diagrams, six polythermal sections, isothermal section at 820 K and the liquidus surface projection were built at the first time. The existence of the large region of the solid solutions based on AgIn{sub 5}Se{sub 8}, Ga{sub 2}Se{sub 3} and AgGa{sub 1?x}In{sub x}Se{sub 2} was investigated. The existence of two ternary phases was established in the Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system. Two single crystals (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} were grown and some of optical properties of them were studied at first time. Display Omitted - Highlights: • Liquidus surface projection was built for Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system. • Solid solution ranges of AgIn{sub 5}Se{sub 8}, Ga{sub 2}Se{sub 3} and AgGa{sub 1?x}In{sub x}Se{sub 2} were investigated. • Two single crystals (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} were grown. • Some optical properties of these single crystals were studied.

  18. SE HAN FINALIZADO LOS PREPARATIVOS PARA LA CONFERENCIA NACIONAL DE JUSTICIA MEDIOAMBIENTAL Y PROGRAMA DE FORMACIÓN 2013

    Broader source: Energy.gov [DOE]

    La National Environmental Justice Conference, Inc. (Conferencia de Justicia Medioambiental) se prepara para otro exitoso acontecimiento, ya que se aproxima la Conferencia Nacional de Justicia...

  19. Diamond-machined ZnSe immersion grating for NIR high-resolution spectroscopy

    SciTech Connect (OSTI)

    Ikeda, Y; Kobayashi, N; Kuzmenko, P J; Little, S L; Yasui, C; Kondo, S; Minami, A; Motohara, K

    2008-07-25T23:59:59.000Z

    ZnSe immersion gratings (n {approx} 2.45) provide the possibility of high-resolution spectroscopy for the near-infrared (NIR) region. Since ZnSe has a lower internal attenuation than other NIR materials, it is most suitable for immersion grating, particularly in short NIR region (0.8-1.4 {micro}m). We are developing an extremely high-resolution spectrograph with {lambda}/{Delta}{lambda} = 100,000, WINERED, customized for the short NIR region, using ZnSe (or ZnS) immersion grating. However, it had been very difficult to make fine grooves on ZnSe substrate with a small pitch of less than 50 {micro}m because ZnSe is a soft/brittle material. We have overcome this problem and successfully machined sharp grooves with fine pitch on ZnSe substrates by nano precision fly-cutting technique at LLNL. The optical testing of the sample grating with HeNe laser shows an excellent performance: the relative efficiency more than 87.4 % at 0.633 {micro}m for a classical grating configuration. The diffraction efficiency when used as an immersion grating is estimated to be more than 65 % at 1 {micro}m. Following this progress, we are about to start machining a grating on a large ZnSe prism with an entrance aperture of 23mm x 50mm and the blaze angle of 70{sup o}.

  20. Hydrothermal synthesis, structure, and magnetic properties of Pu(SeO{sub 3}){sub 2}

    SciTech Connect (OSTI)

    Bray, Travis H. [Department of Chemistry and Biochemistry and Center for Actinide Science, Auburn University, Auburn, AL 36849 (United States); Skanthakumar, S.; Soderholm, L. [Chemistry Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Sykora, Richard E. [Department of Chemistry, University of South Alabama, Mobile, AL 36688 (United States); Haire, Richard G. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Albrecht-Schmitt, Thomas E. [Department of Chemistry and Biochemistry and Center for Actinide Science, Auburn University, Auburn, AL 36849 (United States)], E-mail: albreth@auburn.edu

    2008-03-15T23:59:59.000Z

    The reaction between PuO{sub 2} and SeO{sub 2} under mild hydrothermal conditions results in the formation of Pu(SeO{sub 3}){sub 2} as brick-red prisms. This compound adopts the Ce(SeO{sub 3}){sub 2} structure type, and consists of one-dimensional chains of edge-sharing [PuO{sub 8}] distorted bicapped trigonal prisms linked by [SeO{sub 3}] units into a three-dimensional network. Crystallographic data: Pu(SeO{sub 3}){sub 2}, monoclinic, space group P2{sub 1}/n, a=6.960(1) A, b=10.547(2) A, c=7.245(1) A, {beta}=106.880(9){sup o}, V=508.98(17) A{sup 3}, Z=4 (T=193 K), R(F)=2.92% for 83 parameters with 1140 reflections with I>2{sigma}(I). Magnetic susceptibility data for Pu(SeO{sub 3}){sub 2} are linear from 35 to 320 K and yield an effective moment of 2.71(5) {mu}{sub B} and a Weiss constant of -500(5) K. - Graphical abstract: A depiction of the three-dimensional structure of Pu(SeO{sub 3}){sub 2} formed from the interconnection of one-dimensional chains of edge-sharing PuO{sub 8} dodecahedra by selenite anions.

  1. INCOSE Systems Engineering Handbook v3.2: Improving the Process for SE Practitioners

    SciTech Connect (OSTI)

    R. Douglas Hamelin; David D. Walden; Michael E. Krueger

    2010-07-01T23:59:59.000Z

    The INCOSE Systems Engineering Handbook is the official INCOSE reference document for understanding systems engineering (SE) methods and conducting SE activities. Over the years, the Handbook has evolved to accommodate advances in the SE discipline and now serves as the basis for the Certified Systems Engineering Professional (CSEP) exam. Due to its evolution, the Handbook had become somewhat disjointed in its treatment and presentation of SE topics and was not aligned with the latest version of International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 15288:2008, Systems and Software Engineering. As a result, numerous inconsistencies were identified that could confuse practitioners and directly impact the probability of success in passing the CSEP exam. Further, INCOSE leadership had previously submitted v3.1 of the Handbook to ISO/IEC for consideration as a Technical Report, but was told that the Handbook would have to be updated to conform with the terminology and structure of new ISO/IEC15288:2008, Systems and software engineering, prior to being considered. The revised INCOSE Systems Engineering Handbook v3.2 aligns with the structure and principles of ISO/IEC 15288:2008 and presents the generic SE life-cycle process steps in their entirety, without duplication or redundancy, in a single location within the text. As such, the revised Handbook v3.2 serves as a comprehensive instructional and reference manual for effectively understanding SE processes and conducting SE and better serves certification candidates preparing for the CSEP exam.

  2. Characterization of ZnSe scintillating bolometers for Double Beta Decay

    E-Print Network [OSTI]

    C. Arnaboldi; S. Capelli; O. Cremonesi; L. Gironi; M. Pavan; G. Pessina; S. Pirro

    2010-06-30T23:59:59.000Z

    ZnSe scintillating bolometers are good candidates for future Double Beta Decay searches, because of the 82Se high Q-value and thanks to the possibility of alpha background rejection on the basis of the scintillation signal. In this paper we report the characteristics and the anomalies observed in an extensive study of these devices. Among them, an unexpected high emission from alpha particles, accompanied with an unusual pattern of the light vs. heat scatter plot. The perspectives for the application of this kind of detectors to search for the Neutrinoless Double Beta Decay of 82Se are presented.

  3. Optimal packing size of non-ligated CdSe nanoclusters for microstructure synthesis

    SciTech Connect (OSTI)

    Tefera, Anteneh G.; Mochena, Mogus D. [Department of Physics, Florida A and M University, Tallahassee, Florida 32307 (United States); Johnson, Elijah [School of Environment, Florida A and M University, Tallahassee, Florida 32307 (United States); Dickerson, James [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States)

    2014-09-14T23:59:59.000Z

    Structural and electrostatic properties of nanoclusters of CdSe of diameter 1–2?nm are studied with first principle calculations to determine the optimal size for synthesizing microstructures. Based on robustness of the core structure, i.e., the retention of tetrahedral geometry, hexagonal ring structure, and overall wu{sup ¨}rtzite structure to surface relaxations, we conclude that nanoclusters of ?2?nm diameter are the best candidates to form a dense microstructure with minimal interstitial space. Se-terminated surfaces retain a zigzag structure as Se atoms are pulled out and Cd atoms are pulled in due to relaxation, therefore, are best suited for inter-nanocluster formations.

  4. A comparative transport study of Bi{sub 2}Se{sub 3} and Bi{sub 2}Se{sub 3}/yttrium iron garnet

    SciTech Connect (OSTI)

    Jiang, Zilong; Tang, Chi; Shi, Jing [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Katmis, Ferhat; Wei, Peng; Moodera, Jagadeesh S. [Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-06-02T23:59:59.000Z

    Bilayers of 20 quintuple layer Bi{sub 2}Se{sub 3} on 30?nm thick yttrium iron garnet (YIG) have been grown with molecular beam epitaxy in conjunction with pulsed laser deposition. The presence of the ferri-magnetic insulator YIG causes additional scattering to the surface states of the Bi{sub 2}Se{sub 3} topological insulator layer, as indicated by the temperature dependence of the resistivity. From the two-channel analysis of the Hall data, we find that the surface contribution in the bilayer samples is greatly reduced. Furthermore, the weak antilocalization effect from the surface states is clearly suppressed due to the presence of the YIG layer.

  5. Hidden Superlattice in Tl2(SC6H4S) and Tl2(SeC6H4Se) Solved from Powder X-ray Diffraction

    SciTech Connect (OSTI)

    K Stone; D Turner; M Singh; T Vaid; P Stephens

    2011-12-31T23:59:59.000Z

    The crystal structures of the isostructural title compounds poly[({mu}-benzene-1,4-dithiolato)dithallium], Tl{sub 2}(SC{sub 6}H{sub 4}S), and poly[({mu}-benzene-1,4-diselenolato)dithallium], Tl{sub 2}(SeC{sub 6}H{sub 4}Se), were solved by simulated annealing from high-resolution synchrotron X-ray powder diffraction. Rietveld refinements of an initial structure with one formula unit per triclinic cell gave satisfactory agreement with the data, but led to a structure with impossibly close non-bonded contacts. A disordered model was proposed to alleviate this problem, but an alternative supercell structure leads to slightly improved agreement with the data. The isostructural superlattice structures were confirmed for both compounds through additional data collection, with substantially better counting statistics, which revealed the presence of very weak superlattice peaks not previously seen. Overall, each structure contains Tl-S or Tl-Se two-dimensional networks, connected by phenylene bridges. The sulfur (or selenium) coordination sphere around each thallium is a highly distorted square pyramid or a 'see-saw' shape, depending upon how many Tl-S or Tl-Se interactions are considered to be bonds. In addition, the two compounds contain pairs of Tl{sup I} ions that interact through a closed-shell 'thallophilic' interaction: in the sulfur compound there are two inequivalent pairs of Tl atoms with Tl-Tl distances of 3.49 and 3.58 {angstrom}, while in the selenium compound those Tl-Tl interactions are at 3.54 and 3.63 {angstrom}.

  6. Enhanced Thermoelectric Power and Electronic Correlations in RuSe2

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

    Wang, Kefeng [Brookhaven National Laboratory (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Wang, Aifeng [Brookhaven National Laboratory (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Tomic, A. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Wang, Limin [Brookhaven National Laboratory (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Abeykoon, A.M. Milinda [Brookhaven National Laboratory (BNL), Upton, NY (United States). Photon Sciences Directorate; Dooryhee, E. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Photon Sciences Directorate; Billinge, S. J.L. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Columbia Univ., New York, NY (United States); Petrovic, C. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.

    2015-04-01T23:59:59.000Z

    We report the electronic structure, electric and thermal transport properties of Ru1-xIrxSe2 (x ? 0:2). RuSe2 is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe2 exceeds -200 ?#22;V/K around 730 K. Ir substitution results in the suppression of the resistivity and the Seebeck coefficient, suggesting the removal of the peaks in density of states near the Fermi level. Ru0.8Ir0.2Se2 shows a semiconductor-metal crossover at about 30 K. The magnetic field restores the semiconducting behavior. Our results indicate the importance of the electronic correlations in enhanced thermoelectricity of RuSb2.

  7. Evidence for Gassy Sediments on the Inner Shelf of SE Korea From Geoacoustic Properties

    E-Print Network [OSTI]

    , Gwang H. Lee 6 , Young K. Seo 5 1 * Hawaii Natural Energy Institute, University of Hawaii, P.O.S.T. Bldg Properties; Attenuation; Biodegradation; Bubbles; Core Analysis; Gassy Sediments; SE Korea Shelf #12

  8. Electrical Transport of Topological Insulator-Bi2Se3 and Thermoelectric Properties of Graphene

    E-Print Network [OSTI]

    WEI, PENG

    2011-01-01T23:59:59.000Z

    Hall effect and topological insulators. Phys Today Klitzing,L. & Mele, E. J. Topological insulators in three dimensions.Zhang, H. J. et al. Topological insulators in Bi 2 Se 3 , Bi

  9. Polarization dependent photocurrents in thin films of the topological insulator Bi?Se?

    E-Print Network [OSTI]

    Lau, Claudia (Claudia M.)

    2012-01-01T23:59:59.000Z

    Topological insulators are a new class of three-dimensional quantum materials whose interior or bulk is an insulator but whose surface is a conductor. Bi?Se? is a prototypical topological insulator that physicists at MIT ...

  10. UNIDAD GUADALAJARA La Unidad Guadalajara del Cinvestav se inici el 14 de noviembre de 1988 con

    E-Print Network [OSTI]

    años de distancia, la Unidad Guadalajara se ha convertido en uno de los grupos de ingeniería eléctrica, Canadá, y Japón. La Unidad Guadalajara del Cinvestav tiene cinco grupos de trabajo que desa- rrollan

  11. UNIDAD GUADALAJARA La Unidad Guadalajara del Cinvestav se inici el 14 de noviembre de 1988 con

    E-Print Network [OSTI]

    años de distancia, la Unidad Guadalajara se ha convertido en uno de los grupos de ingeniería eléctrica Estados Unidos, Canadá, y Japón. La Unidad Guadalajara del Cinvestav tiene cinco grupos de trabajo que

  12. WEATHERIZATION INDUSTRIES SAVE ENERGY ST SE SALEM, OREGON 97301 (503) 5691381 WEATHERIZATIONALLIES@GMAIL.COM

    E-Print Network [OSTI]

    WEATHERIZATION INDUSTRIES SAVE ENERGY 565 21ST ST SE SALEM, OREGON 97301 · (503) 5691381 · WEATHERIZATIONALLIES@GMAIL.COM COMMENTS ON ACHIEVABLE SAVINGS: A RETROSPECTIVE LOOK AT THE NORTHWEST POWER AND CONSERVATION COUNCIL'S CONSERVATION PLANNING ASSUMPTIONS Weatherization Industries Save Energy (WISE

  13. Structure, Magnetism, and Transport of CuCr2Se4 Thin Films

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    Structure, Magnetism, and Transport of CuCr 2 Se 4 Thindichroism shows that the magnetism persists to the surfacesuch as the nature of magnetism at surfaces and interfaces.

  14. Phonon properties of BaFe?X? (X=S, Se) spin ladder compounds

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

    Popovicq, Z. V.; Petrovic, C.; Scepanovic, M.; Lazarevic, N.; Opacic, M.; Radonjic, M. M.; Tanaskovic, D.; Lei, Hechang

    2015-02-01T23:59:59.000Z

    We present the Raman scattering spectra of the S=2 spin ladder compounds BaFe?X? (X=S,Se) in a temperature range between 20 and 400 K. Although the crystal structures of these two compounds are both orthorhombic and very similar, they are not isostructural. The unit cell of BaFe?S? (BaFe?Se?) is base-centered Cmcm (primitive Pnma), giving 18 (36) modes to be observed in the Raman scattering experiment. We have detected almost all Raman active modes, predicted by factor group analysis, which can be observed from the cleavage planes of these compounds. Assignment of the observed Raman modes of BaFe?S(Se)? is supported by themore »lattice dynamics calculations. The antiferromagnetic long-range spin ordering in BaFe?Se? below TN=255K leaves a fingerprint both in the A1g and B3g phonon mode linewidth and energy.« less

  15. Time resolved fluorescence of CdSe nanocrystals using single molecule spectroscopy

    E-Print Network [OSTI]

    Fisher, Brent R

    2005-01-01T23:59:59.000Z

    A wide variety of spectroscopic studies of CdSe nanocrystals (NCs) are presented in this thesis, all studying some aspect of the temporal evolution of NC fluorescence tinder different conditions. In particular the methods ...

  16. Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles

    E-Print Network [OSTI]

    Chen, Jixin

    2011-08-08T23:59:59.000Z

    nanosphere (left) and nanoprism (right) solutions and (B) their corresponding absorption spectra displayed in yellow and green line, respectively. (C) TEM image of photoinduced Ag nanoprisms. The inserts show the electron diffraction analysis... this synthetic method, typical commercial CdSe nanocrystals have a size deviation less than 10% and narrow emission spectra with peak widths at half height of around 30- 50 nm for small ones that have 4 nm in diameter. The color changes of the CdSe quantum...

  17. Unique Challenges Accompany Thick-Shell CdSe/nCdS (n > 10) Nanocrystal Synthesis

    SciTech Connect (OSTI)

    Guo, Y; Marchuk, K; Abraham, R; Sampat, S; Abraham, R.; Fang, N; Malko, AV; Vela, J

    2011-12-23T23:59:59.000Z

    Thick-shell CdSe/nCdS (n {ge} 10) nanocrystals were recently reported that show remarkably suppressed fluorescence intermittency or 'blinking' at the single-particle level as well as slow rates of Auger decay. Unfortunately, whereas CdSe/nCdS nanocrystal synthesis is well-developed up to n {le} 6 CdS monolayers (MLs), reproducible syntheses for n {ge} 10 MLs are less understood. Known procedures sometimes result in homogeneous CdS nucleation instead of heterogeneous, epitaxial CdS nucleation on CdSe, leading to broad and multimodal particle size distributions. Critically, obtained core/shell sizes are often below those desired. This article describes synthetic conditions specific to thick-shell growth (n {ge} 10 and n {ge} 20 MLs) on both small (sub2 nm) and large (>4.5 nm) CdSe cores. We find added secondary amine and low concentration of CdSe cores and molecular precursors give desired core/shell sizes. Amine-induced, partial etching of CdSe cores results in apparent shell-thicknesses slightly beyond those desired, especially for very-thick shells (n {ge} 20 MLs). Thermal ripening and fast precursor injection lead to undesired homogeneous CdS nucleation and incomplete shell growth. Core/shells derived from small CdSe (1.9 nm) have longer PL lifetimes and more pronounced blinking at single-particle level compared with those derived from large CdSe (4.7 nm). We expect our new synthetic approach will lead to a larger throughput of these materials, increasing their availability for fundamental studies and applications.

  18. Synthesis of CdSe quantum dots for quantum dot sensitized solar cell

    SciTech Connect (OSTI)

    Singh, Neetu, E-mail: singh.neetu1985@gmail.com; Kapoor, Avinashi [Department of Electronic Science, University of Delhi South Campus, New Delhi-110 021 (India); Kumar, Vinod [Department of Physics, University of the Free State, Bloemfontein, ZA9300 (South Africa); Mehra, R. M. [School of Engineering and Technology, Sharda University, Greater Noida-201 306, U.P. (India)

    2014-04-24T23:59:59.000Z

    CdSe Quantum Dots (QDs) of size 0.85 nm were synthesized using chemical route. ZnO based Quantum Dot Sensitized Solar Cell (QDSSC) was fabricated using CdSe QDs as sensitizer. The Pre-synthesized QDs were found to be successfully adsorbed on front ZnO electrode and had potential to replace organic dyes in Dye Sensitized Solar Cells (DSSCs). The efficiency of QDSSC was obtained to be 2.06 % at AM 1.5.

  19. Native defects in tetradymite Bi2(TexSe3-x) topological insulators

    SciTech Connect (OSTI)

    Wang, Lin-Lin [Ames Laboratory; Huang, Mianliang [South Dakota School of Mines; Thimmaiah, Srinivasa [Ames Laboratory; Alam, Aftab [Ames Laboratory; Budko, Sergey L. [Ames Laboratory; Kaminski, Adam [Ames Laboratory; Lograsso, Thomas A. [Ames Laboratory; Canfield, Paul [Ames Laboratory; Johnson, Duane D. [Ames Laboratory

    2013-03-08T23:59:59.000Z

    Formation energies of native defects in Bi2(TexSe3-x), with comparison to ideal Bi2Te2S, are calculated in density-functional theory to assess transport properties. Bi2Se3 is found to be n type for both Bi- and Se-rich growth conditions, while Bi2Te3 changes from n to p type going from Te- to Bi-rich conditions, as observed. Bi2Te2Se and Bi2Te2S are generally n type, explaining observed heavily doped n-type behavior in most samples. A (0/-) transition level at 16 meV above valence-band maximum for Bi on Te antisites in Bi2Te2Se is related to the observed thermally active transport gap causing a p-to-n transition at low temperature. Bi2(TexSe3-x) with x>2 are predicted to have high bulk resistivity due to effective carrier compensation when approaching the n-to-p crossover. Predicted behaviors are confirmed from characterization of our grown single crystals.

  20. Novel Approaches to Wide Bandgap CuInSe2 Based Absorbers

    SciTech Connect (OSTI)

    William N. Shafarman

    2011-04-28T23:59:59.000Z

    This project targeted the development of high performance wide bandgap solar cells based on thin film alloys of CuInSe2 to relax constraints on module design and enable tandem solar cell structures. This addressed goals of the Solar Energy Technologies Program for Next Generation PV to develop technology needed for higher thin film module efficiency as a means to reduce costs. Specific objectives of the research project were: 1) to develop the processes and materials required to improve the performance of wide bandgap thin film solar cells based on alloys of CuInSe2, and 2) to provide the fundamental science and engineering basis for the material, electronic, and device properties required to effectively apply these processes and materials to commercial manufacture. CuInSe2-based photovoltaics have established the highest efficiencies of the thin film materials at both the cell and module scales and are actively being scaled up to commercialization. In the highest efficiency cells and modules, the optical bandgap, a function of the CuInSe2-based alloy composition, is relatively low compared to the optimum match to the solar spectrum. Wider bandgap alloys of CuInSe2 produce higher cell voltages which can improve module performance and enable the development of tandem solar cells to boost the overall efficiency. A focus for the project was alloying with silver to form (AgCu)(InGa)Se2 pentenary thin films deposited by elemental co-evaporation which gives the broadest range of control of composition and material properties. This alloy has a lower melting temperature than Ag-free, Cu-based chalcopyrite compounds, which may enable films to be formed with lower defect densities and the (AgCu)(InGa)Se2 films give improved material properties and better device performance with increasing bandgap. A comprehensive characterization of optical, structural, and electronic properties of (AgCu)(InGa)Se2 was completed over the complete compositional range 0 ? Ga/(In+Ga) ? 1 and 0 ? Ag/(Ag+Cu) ? 1. Evidence of improved material quality includes reduced sub-bandgap optical absorption, sharper bandtails, and increased grain size with Ag addition. The Ag alloying was shown to increase the range of bandgaps over which solar cells can be fabricated without any drop-off in performance. With bandgap greater than 1.6 eV, in the range needed for tandem solar cells, (AgCu)(InGa)Se2 gave higher efficiency than other CuInSe2-based alloys. Using a simple single-stage co-evaporation process, a solar cell with 17.6% efficiency using a film with bandgap = 1.3 eV was achieved, demonstrating the viability of (AgCu)(InGa)Se2 for high efficiency devices. With a three-stage co-evaporation process for (AgCu)(InGa)Se2 deposition a device with efficiency = 13.0 % and VOC = 890 mV with JSC = 20.5 mA/cm2, FF = 71.3% was achieved. This surpasses the performance of other wide bandgap CuInSe2-based solar cells. Detailed characterization of the electronic properties of the materials and devices including the application of advanced admittance-based easements was completed.

  1. Optically pumped quantum-dot Cd(Zn)Se/ZnSe laser and microchip converter for yellow-green spectral region

    SciTech Connect (OSTI)

    Lutsenko, E V; Voinilovich, A G; Rzheutskii, N V; Pavlovskii, V N; Yablonskii, G P; Sorokin, S V; Gronin, S V; Sedova, I V; Kop'ev, Petr S; Ivanov, Sergei V; Alanzi, M; Hamidalddin, A; Alyamani, A

    2013-05-31T23:59:59.000Z

    The room temperature laser generation in the yellow-green ({lambda} = 558.5-566.7 nm) spectral range has been demonstrated under optical pumping by a pulsed nitrogen laser of Cd(Zn)Se/ZnSe quantum dot heterostructures. The maximum achieved laser wavelength was as high as {lambda} = 566.7 nm at a laser cavity length of 945 {mu}m. High values of both the output pulsed power (up to 50 W) and the external differential quantum efficiency ({approx}60%) were obtained at a cavity length of 435 {mu}m. Both a high quality of the laser heterostructure and a low lasing threshold ({approx}2 kW cm{sup -2}) make it possible to use a pulsed InGaN laser diode as a pump source. A laser microchip converter based on this heterostructure has demonstrated a maximum output pulse power of {approx}90 mW at {lambda} = 560 nm. The microchip converter was placed in a standard TO-18 (5.6 mm in diameter) laser diode package. (semiconductor lasers. physics and technology)

  2. A Novel and Functional Single Layer Sheet of ZnSe

    SciTech Connect (OSTI)

    Zhou, Jia [ORNL; Sumpter, Bobby G [ORNL; Kent, Paul R [ORNL; Huang, Jingsong [ORNL

    2015-01-01T23:59:59.000Z

    In this Communication, we report a novel singlelayer sheet of ZnSe, with a three-atomic thickness, which demonstrates a strong quantum confinement effect by exhibiting a large blue shift of 2.0 eV in its absorption edge relative to the zinc blende (ZB) bulk phase. Theoretical optical absorbance shows that the largest absorption of this ultrathin single-layer sheet of ZnSe occurs at a wavelength similar to its four-atom-thick doublelayer counterpart but with higher photoabsorption efficiency, suggesting a superior behavior on incident photon-to-current conversion efficiency for solar water splitting, among other potential applications. The results presented herein for ZnSe may be generalized to other group II-VI analogues.

  3. Critical Fields, Thermally Activated Transport, and Critical Current Density of Beta-FeSe Single Crystals

    SciTech Connect (OSTI)

    Petrovic, C.; Lei, H.; Hu, R.

    2011-07-27T23:59:59.000Z

    We present critical fields, thermally activated flux flow (TAFF), and critical current density of tetragonal phase {beta}-FeSe single crystals. The upper critical fields H{sub c2}(T) for H {parallel} (101) and H {perpendicular} (101) are nearly isotropic and are likely governed by the Pauli limiting process. The large Ginzburg-Landau parameter {Kappa} {approx} 72.3(2) indicates that {beta}-FeSe is a type-II superconductor with a smaller penetration depth than in Fe(Te, Se). The resistivity below T{sub c} follows Arrhenius TAFF behavior. For both field directions below 30 kOe, single-vortex pinning is dominant, whereas collective creep becomes important above 30 kOe. The critical current density J{sub c} from M-H loops for H {parallel} (101) is about five times larger than for H {perpendicular} (101), yet much smaller than in other iron-based superconductors.

  4. Recrystallization method to selenization of thin-film Cu(In,Ga)Se.sub.2 for semiconductor device applications

    DOE Patents [OSTI]

    Albin, David S. (Denver, CO); Carapella, Jeffrey J. (Evergreen, CO); Tuttle, John R. (Denver, CO); Contreras, Miguel A. (Golden, CO); Gabor, Andrew M. (Boulder, CO); Noufi, Rommel (Golden, CO); Tennant, Andrew L. (Denver, CO)

    1995-07-25T23:59:59.000Z

    A process for fabricating slightly Cu-poor thin-films of Cu(In,Ga)Se.sub.2 on a substrate for semiconductor device applications includes the steps of forming initially a slightly Cu-rich, phase separated, mixture of Cu(In,Ga)Se.sub.2 :Cu.sub.x Se on the substrate in solid form followed by exposure of the Cu(In,Ga)Se.sub.2 :Cu.sub.x Se solid mixture to an overpressure of Se vapor and (In,Ga) vapor for deposition on the Cu(In,Ga)Se.sub.2 :Cu.sub.x Se solid mixture while simultaneously increasing the temperature of the solid mixture toward a recrystallization temperature (about 550.degree. C.) at which Cu(In,Ga)Se.sub.2 is solid and Cu.sub.x Se is liquid. The (In,Ga) flux is terminated while the Se overpressure flux and the recrystallization temperature are maintained to recrystallize the Cu.sub.x Se with the (In, Ga) that was deposited during the temperature transition and with the Se vapor to form the thin-film of slightly Cu-poor Cu.sub.x (In,Ga).sub.y Se.sub.z. The initial Cu-rich, phase separated large grain mixture of Cu(In,Ga)Se.sub.2 :Cu.sub.x Se can be made by sequentially depositing or co-depositing the metal precursors, Cu and (In, Ga), on the substrate at room temperature, ramping up the thin-film temperature in the presence of Se overpressure to a moderate anneal temperature (about 450.degree. C.) and holding that temperature and the Se overpressure for an annealing period. A nonselenizing, low temperature anneal at about 100.degree. C. can also be used to homogenize the precursors on the substrates before the selenizing, moderate temperature anneal.

  5. Thermodynamic Model for the Solubility of Ba(SeO4, SO4) Precipitates

    SciTech Connect (OSTI)

    Rai, D.; Felmy, Andrew R.; Moore, Dean A.; Kitamura, Akira; Yoshikawa, Hideki; Doi, Reisuke; Yoshida, Yasushi

    2014-08-15T23:59:59.000Z

    Abstract: The solubility of Ba(SeO4, SO4) precipitates was determined as a function of the BaSeO4 mole fractions, ranging from 0.0015 to 0.3830, and time with an equilibration period extending to as long as 302 days. Equilibrium/steady state conditions in this system are reached in ? 65 days. Pitzer’s ion interaction model was used to calculate solid and aqueous phase activity coefficients. Thermodynamic analyses showed that the data do not satisfy Gibbs-Duhem equation, thereby demonstrating that a single-solid solution phase does not control both the selenate and sulfate concentrations. Our extensive data with log 10 [Ba] ranging from ?3.6 to ?5.9 mol kg?1, log 10 [SeO4] rangingfrom?3.6 to -5.2 mol kg?1, and log 10 [SO4] ranging from?4.0 to ?5.3 mol kg?1 can be explained with the formation of an ideal BaSeO4 solid solution phase that controls the selenium concentrations and a slightly disordered/less-crystalline BaSO4(s) (log 10𝐾?sp = ?9.5 instead of ?10.05 for barite) that controls the sulfate concentrations. In these experiments the BaSO4 component of the solid solution phase never reaches thermodynamic equilibrium with the aqueous phase. Thermodynamic interpretations of the data show that both the ideal BaSeO4 solid solution phase and less-crystalline BaSO4 (s) phase are in equilibrium with each other in the entire range of BaSeO 4 mole fractions investigated in this study.

  6. Speciation, characterization, and mobility of As, Se, and Hg in flue gas desulphurization residues

    SciTech Connect (OSTI)

    Souhail R. Al-Abed; Gautham Jegadeesan; Kirk G. Scheckel; Thabet Tolaymat [United States Environmental Protection Agency, Cincinnati, OH (United States). National Risk Management Research Laboratory

    2008-03-01T23:59:59.000Z

    Flue gas from coal combustion contains significant amounts of volatile toxic trace elements such as arsenic (As), selenium (Se), and mercury (Hg). The capture of these elements in the flue gas desulphurization (FGD) scrubber unit has resulted in generation of a metal-laden residue. With increasing reuse of the FGD residues in beneficial applications, it is important to determine metal speciation and mobility to understand the environmental impact of its reuse. In this paper, we report the solid phase speciation of As, Se, and Hg in FGD residues using X-ray absorption spectroscopy (XAS), X-ray fluorescence spectroscopy (XRF), and sequential chemical extraction (SCE) techniques. The SCE results combined with XRF data indicated a strong possibility of As association with iron oxides, whereas Se was distributed among all geochemical phases. Hg appeared to be mainly distributed in the strong-complexed phase. XRF images also suggested a strong association of Hg with Fe oxide materials within FGD residues. XAS analysis indicated that As existed in its oxidized state (As(V)), whereas Se and Hg was observed in primarily reduced states as selenite (Se(IV)) and Hg(I), respectively. The results from the SCE and variable pH leaching tests indicated that the labile fractions of As, Se, and Hg were fairly low and thus suggestive of their stability in the FGD residues. However, the presence of a fine fraction enriched in metal content in the FGD residue suggested that size fractionation is important in assessing the environmental risks associated with their reuse. 34 refs., 3 figs., 4 tabs.

  7. Ann bay lodyans 3 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 3 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml ANN BAY LODYANS 3 Se Bryant Freeman...

  8. Ann bay lodyans 16 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 16 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml ANN BAYL0DYANS16 Yon Ti Degi Se Bryant...

  9. Ann bay lodyans 1 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 1 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml ANN BAY LODYANS 1 Se Bryant Freeman...

  10. Ann bay lodyans 8 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    dlo." Eklid Etyen, Teryewouj 1 2 TI GOUT TI GOUT, KONPE CHAT PEDI Yon jou diskisyon mete pye ant konpe Chen ak konpe Chat. Te gen yon moso vyann ate a. Konpe Chen di se li menm ki te we I anvan, men konpe Chat di se li menm ki te we I anvan... mak sonje. Konsa, Chat ale kay yon boko. Li di: "Papa, m vin lakay ou pou touye tout chen ki gen sou late. M ap peye ou mezi ou vie pou sa." Boko a reponn: "A monche, m ap ba ou sa sou de chez. Eske ou ka jwenn yon ti gout pipi chen?" Konpe Chat...

  11. Investigations of CuInSe sub 2 thin films and contacts

    SciTech Connect (OSTI)

    Nicolet, M.A. (California Inst. of Tech., Pasadena, CA (United States))

    1991-10-01T23:59:59.000Z

    This report describes research into electrical contacts for copper indium diselenide (CuInSe{sub 2}) polycrystalline thin films used for solar cell applications. Molybdenum contacts have historically been the most promising for heterojunction solar cells. This program studied contact stability by investigating thermally induced bilayer reactions between molybdenum and copper, indium, and selenium. Because selenization is widely used to fabricate CuInSe{sub 2} thin films for photovoltaic cells, a second part of the program investigated how the morphologies, phases, and reactions of pre-selenization Cu-In structures are affected by the deposition process and heat treatments. 7 refs., 6 figs.

  12. Ann bay lodyans 2 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 2 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Communication and Copyright. Please share your stories about how Open Access to this article benefits you. This is the published version of the book, made available with the permission of the publisher. Freeman, Bryant C., ed. Ann bay lodyans 2 / se Bryant...

  13. Ann bay lodyans 5 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 5 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Communication and Copyright. Please share your stories about how Open Access to this article benefits you. This is the published version of the book, made available with the permission of the publisher. Freeman, Bryant C., ed. Ann bay lodyans 5 / se Bryant...

  14. Ann bay lodyans 4 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 4 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml Tl CHAT: PI PITI PI RED Vwala se te...

  15. Ann bay lodyans 15 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 15 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml ANN BAY LODYANS15 Se Bryant Freeman...

  16. Ann bay lodyans 6 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 6 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml ANN BAYLODYANS g Se Bryant Freeman...

  17. Pair correlations in nuclei involved in neutrinoless double beta decay: 76Ge and 76Se

    E-Print Network [OSTI]

    S. J. Freeman; J. P. Schiffer; A. C. C. Villari; J. A. Clark; C. Deibel; S. Gros; A. Heinz; D. Hirata; C. L. Jiang; B. P. Kay; A. Parikh; P. D. Parker; J. Qian; K. E. Rehm; X. D. Tang; V. Werner; C. Wrede

    2007-03-23T23:59:59.000Z

    Precision measurements were carried out to test the similarities between the ground states of 76Ge and 76Se. The extent to which these two nuclei can be characterized as consisting of correlated pairs of neutrons in a BCS-like ground state was studied. The pair removal (p,t) reaction was measured at the far forward angle of 3 degrees. The relative cross sections are consistent (at the 5% level) with the description of these nuclei in terms of a correlated pairing state outside the N=28 closed shells with no pairing vibrations. Data were also obtained for 74Ge and 78Se.

  18. 186 VHDL: LENGUAJE PARA S INTESIS Y MODELADO DE CIRCUITOS c El cronograma correspondiente, como resultado de la simulacion, se muestra en la

    E-Print Network [OSTI]

    Valencia, Universidad de

    , como resultado de la simulaciâ??on, se muestra en la figura 12.6 donde se han incluido todas las se

  19. Supplemental Figure 1. Root lengths of S. pinnata and S. albescens grown on vertically placed agar plates after 30 days of growth from germination. Plants treated without () Se (open bars) and with (+) 20 M SeO4

    E-Print Network [OSTI]

    ) and with (+) 20 M SeO4 2- (gray bars). Data represent the average of 4-5 different plants ± SE. P-values using and S. albescens grown with or without 20 M SeO4 2- . The only significant difference between treatments. pinnata when compared with S. albescens grown with and without 20 M SeO4 2- . #12;Supplemental Figure 4

  20. Method of fabricating high-efficiency Cu(In,Ga)(Se,S){sub 2} thin films for solar cells

    DOE Patents [OSTI]

    Noufi, R.; Gabor, A.M.; Tuttle, J.R.; Tennant, A.L.; Contreras, M.A.; Albin, D.S.; Carapella, J.J.

    1995-08-15T23:59:59.000Z

    A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S){sub 2} comprises depositing a first layer of (In,Ga){sub x} (Se,S){sub y} followed by depositing just enough Cu+(Se,S) or Cu{sub x} (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga){sub x} (Se,S){sub y} is deposited first, followed by deposition of all the Cu+(Se,S) or Cu{sub x} (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu{sub x} (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga){sub x} (Se,S){sub y} to go slightly Cu-poor in the final Cu(In,Ga)(Se,S){sub 2} thin film. 5 figs.

  1. Distance-Engineered Plasmon-Enhanced Light Harvesting in CdSe Quantum Dots

    E-Print Network [OSTI]

    Distance-Engineered Plasmon-Enhanced Light Harvesting in CdSe Quantum Dots Shengye Jin,,§, Erica De) is essential for the development of efficient QD-based solar energy conversion systems. In this study, plasmon as a function of interparticle (QD to Ag NP) distance. Up to 24-fold plasmonic enhancement of fluorescence from

  2. To appear in JSiSE, 18(2), 2001 July 30, 2001

    E-Print Network [OSTI]

    Matsuda, Noboru

    To appear in JSiSE, 18(2), 2001 July 30, 2001 1. (Intelligent Tutoring System: ITS) () "" 2. Graesser (1995) Chi (2001 to appear) #12;Graesser Chi Graesser 70 Chi Graesser Chi ITS ITS "" 3. (Graesser , 2001 to appear) - Building Dialogue Systems for Tutoring

  3. FI 10 19 dcembre 2006 page Alan Turing se fraye un chemin jusqu'

    E-Print Network [OSTI]

    Teuscher, Christof

    FI 10 ­ 19 décembre 2006 ­ page Alan Turing se fraye un chemin jusqu'à la place de lPiccard,cheminJeanTschumi,avenueForel,rue RobertMercier,chemin, place ou rueAlanTuring. EtquefaisaitAlanTuringcheminfaisant?Leplus souvent,craqueurducodesecretdela machineEnigma?Certesexagéré,maisle succèsaplusieursparentsetAlanTuring estaumoinslegrandpèreoul

  4. From Bad to Worse: Senior economic inSecurity on the riSe

    E-Print Network [OSTI]

    Snider, Barry B.

    From Bad to Worse: Senior economic inSecurity on the riSe Tatjana Meschede Laura Sullivan Thomas the Senior Financial Stability Index, economic insecurity among senior households increased by one demographic groups, economic security of seniors has deteriorated further. Contrary to the popular belief

  5. Molecular Adsorption to LiMo3Se3 Nanowire Film Chemiresistors

    E-Print Network [OSTI]

    Chiang, Shirley

    Molecular Adsorption to LiMo3Se3 Nanowire Film Chemiresistors Xiubin Qi, Frank E. Osterloh,*, S. A that the temporal and steady-state resistance changes of the films depend on the time following the adsorption and on the number of molecules that adsorb to the nanowire films at a given pressure. The adsorption ability

  6. Hydrogen adsorption on Pd/TiFe (110) surface S.E. Kulkovaa

    E-Print Network [OSTI]

    Kim, Jai Sam

    Hydrogen adsorption on Pd/TiFe (110) surface S.E. Kulkovaa , S.V. Eremeeva,b,*, V.E. Egorushkinc February 2003 by E.L. Ivchenko Abstract Adsorption of hydrogen on the TiFe (110) surface covered the local density approximation. Influence of palladium coating to adsorption properties of the TiFe (110

  7. A n n u A l Campus seCurity And

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    A n n u A l Campus seCurity And Fire saFety report 2012 #12;Dear UC Santa Cruz Community, UC Santa are primarily responsible for ensuring the safety and security of the UC Santa Cruz community from all hazards in the responsibility of keeping our community safe. As such, we encourage you to read our Annual Campus Security

  8. Mn-Substituted Inorganic-Organic Hybrid Materials Based on ZnSe

    E-Print Network [OSTI]

    Li, Jing

    for optoelectronics and information storage technology. In this study, we demonstrate that the hybrid nanostructuresMn-Substituted Inorganic-Organic Hybrid Materials Based on ZnSe: Nanostructures That May Lead are highly desirable and extremely attractive in the development of new multifunctional devices

  9. Electrodeposition of CuGaSe2 from Thiocyanate-Containing Electrolytes

    E-Print Network [OSTI]

    Suni, Ian Ivar

    . Manuscript received September 8, 2010. Published December 2, 2010. CuInxGa1-xSe2 CIGS thin film solar cells- nation velocities.1 Thin film solar cells promise significant economic benefits, because the optical, electrochemical deposition methods may be significantly less expensive for scale-up of thin film solar cells,3

  10. Diffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells

    E-Print Network [OSTI]

    Rockett, Angus

    conversion efficiency of solar cells made from this material [1]. One of the special qualities of the CIGS improve the solar cell performance. In many of the different CIGS fabrication techniques, an in depthDiffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells O. Lundberga,*, J. Lua , A

  11. Mechanical impedance and CPX noise of SMA V.F. Vazquez and S.E. Paje

    E-Print Network [OSTI]

    Boyer, Edmond

    to the volume population affected, are transportation systems like motor vehicles. Tire road noise is the noiseMechanical impedance and CPX noise of SMA pavements V.F. V´azquez and S.E. Paje UCLM-LA2IC, Av 2012 Nantes Conference 23-27 April 2012, Nantes, France 167 #12;CPX noise is the sound measured

  12. Runions LMDZ6 se lancer dans la prparation des configuration futures,

    E-Print Network [OSTI]

    Madeleine, Jean-Baptiste

    . Première réunion improvisée au milieu de l'été parce qu'on se posait des questions sur le bout par lequel 19 paramètres, etc ...) - Changement de code radiatif et nouveaux forçages pour IPCC

  13. Photovoltaic effect in InSe Application to Solar Energy Conversion

    E-Print Network [OSTI]

    Boyer, Edmond

    253 Photovoltaic effect in InSe Application to Solar Energy Conversion A. Segura, J. P. Guesdon, JSe is shown to be a new material with attractive characteristics for solar energy conversion. PerformanceV at 300 K and it is thus close to the theoretical optimum for solar energy conversion. Since its transport

  14. SeRLoc: Secure Range-Independent Localization for Wireless Sensor Networks

    E-Print Network [OSTI]

    Hochberg, Michael

    SeRLoc: Secure Range-Independent Localization for Wireless Sensor Networks Loukas Lazos and Radha, radha}@ee.washington.edu ABSTRACT In many applications of wireless sensor networks (WSN), sensors Localization, Wireless sensor networks, range-independent This work was supported in part by the following

  15. RisNyt NO2 2005 I de kommende rtier vil vi se store

    E-Print Network [OSTI]

    fjerde i en se- rie, der sætter energiemner i perspektiv på globalt, regionalt og dansk niveau. Danmark har gode muligheder for at bevare førertrøjen I Danmark er vi allerede nået langt. Energi vigtigere rolle og især vindenergi er kraftigt udbygget. Samtidig kan Danmark fungere som en slags "buffer

  16. Polarized Luminescence of Defects in CuGaSe2 Susanne Siebentritt1,2

    E-Print Network [OSTI]

    Rockett, Angus

    ). But for the whole group of I-III-VI2 chalcopyrite semiconductors no reliable identification of native defects by ESR been found in CuInSe2. [14] In the effort of relating the energy positions of the defects to defect. Res. Soc. Symp. Proc. Vol. 1012 © 2007 Materials Research Society 1012-Y13-01 #12;the experiment

  17. 7900 SE 28th Street, Suite 200 Mercer, Island, WA 98040-2970

    E-Print Network [OSTI]

    7900 SE 28th Street, Suite 200 Mercer, Island, WA 98040-2970 v 206.236.7200 f 206.236.3019 www Administration. The Joint Proposal is a comprehensive settlement that will bring to an end the long costs, when the responsibility for reaching agreements with IPPs, is dispersed directly to the load

  18. Characterization of an FFDM unit based on a-Se direct conversion detector

    E-Print Network [OSTI]

    Lanconelli, Nico

    Characterization of an FFDM unit based on a-Se direct conversion detector Achille Albanese1 µm. The direct conversion of X-rays into charge provides excellent imaging performance. In this work, detectors based on a direct-conversion technology seem to give a better performance, especially at high

  19. A highly efficient (>6%) Cd1xMnxSe quantum dot sensitized solar cell

    E-Print Network [OSTI]

    Cao, Guozhong

    A highly efficient (>6%) Cd1ÀxMnxSe quantum dot sensitized solar cell Jianjun Tian,*a Lili Lv,a Chengbin Fei,b Yajie Wang,b Xiaoguang Liua and Guozhong Cao*bc Quantum dot sensitized solar cells (QDSCs-effective solar cell. The design and synthesis of quantum dots (QDs) for achieving high photoelectric performance

  20. Phonon and thermal properties of exfoliated TaSe2 thin films T. R. Pope,2

    E-Print Network [OSTI]

    films exfoliated from TaSe2 and other metal dichalcogenides, as well as for evaluating self-heating-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California its bulk value of $16 W/mK to $9 W/mK in 45-nm thick films. The measurement of electrical resistivity

  1. Xenosaurus phalaroanthereon: Edmica a Oaxaca y se distribuye en dos localidades en la

    E-Print Network [OSTI]

    Nacional Autónoma de México, Universidad

    Oficial Mexicana sólo se encuentran enlistadas tres de las especies que conforman el género (X. grandis, X concretas para su conservación y evaluar el estado de las poblaciones existentes. A pesar de que en la Norma:Xenosauridae) del sureste de Hidalgo, México. Boletín de la Sociedad Herpetológica Mexicana 15:20-22. Por: Luis

  2. Study of light-induced vector changes in the local atomic structure of AsSe glasses by EXAFS

    E-Print Network [OSTI]

    Drabold, David

    Study of light-induced vector changes in the local atomic structure of As­Se glasses by EXAFS G changes in the local structure of As­Se glasses using extended X-ray ab- sorption fine structure (EXAFS

  3. First-principles molecular-dynamics study of glassy As2Se3 Jun Li and D. A. Drabold

    E-Print Network [OSTI]

    Drabold, David

    static structure factor in the range 2­6 Å 1 . The preferred structural unit is pyramidal AsSe3 loosely on the cluster model8 consisting mostly of pyramidal AsSe3 molecules,9 and the other is the layer structure using a molecular model and several vibrational frequencies were assigned to pyramidal AsSe3

  4. Thermoelectric properties of indium doped PbTe{sub 1-y}Se{sub y} alloys

    SciTech Connect (OSTI)

    Bali, Ashoka; Mallik, Ramesh Chandra, E-mail: rcmallik@physics.iisc.ernet.in [Thermoelectric Materials and Devices Laboratory, Department of Physics, Indian Institute of Science, Bangalore 560012, Karnataka (India); Wang, Heng; Snyder, G. Jeffrey [Department of Materials Science, California Institute of Technology, Pasadena, California 91125 (United States)

    2014-07-21T23:59:59.000Z

    Lead telluride and its alloys are well known for their thermoelectric applications. Here, a systematic study of PbTe{sub 1-y}Se{sub y} alloys doped with indium has been done. The powder X-Ray diffraction combined with Rietveld analysis confirmed the polycrystalline single phase nature of the samples, while microstructural analysis with scanning electron microscope results showed densification of samples and presence of micrometer sized particles. The temperature dependent transport properties showed that in these alloys, indium neither pinned the Fermi level as it does in PbTe, nor acted as a resonant dopant as in SnTe. At high temperatures, bipolar effect was observed which restricted the zT to 0.66 at 800?K for the sample with 30% Se content.

  5. Algorithmically scalable block preconditioner for fully implicit shallow water equations in CAM-SE

    SciTech Connect (OSTI)

    Lott, P Aaron [Lawrence Livermore National Laboratory (LLNL); Woodward, Carol [Lawrence Livermore National Laboratory (LLNL); Evans, Katherine J [ORNL

    2015-01-01T23:59:59.000Z

    Performing accurate and efficient numerical simulation of global atmospheric climate models is challenging due to the disparate length and time scales over which physical processes interact. Implicit solvers enable the physical system to be integrated with a time step commensurate with processes being studied. The dominant cost of an implicit time step is the ancillary linear system solves, so we have developed a preconditioner aimed at improving the efficiency of these linear system solves. Our preconditioner is based on an approximate block factorization of the linearized shallow-water equations and has been implemented within the spectral element dynamical core within the Community Atmospheric Model (CAM-SE). In this paper we discuss the development and scalability of the preconditioner for a suite of test cases with the implicit shallow-water solver within CAM-SE.

  6. CdS/PbSe heterojunction for high temperature mid-infrared photovoltaic detector applications

    SciTech Connect (OSTI)

    Weng, Binbin, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu; Qiu, Jijun; Zhao, Lihua; Chang, Caleb [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Shi, Zhisheng, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Nanolight, Inc., Norman, Oklahoma 73069 (United States)

    2014-03-24T23:59:59.000Z

    n-CdS/p-PbSe heterojunction is investigated. A thin CdS film is deposited by chemical bath deposition on top of epitaxial PbSe film by molecular beam epitaxy on Silicon. Current-voltage measurements demonstrate very good junction characteristics with rectifying ratio of ?178 and ideality factor of 1.79 at 300?K. Detectors made with such structure exhibit mid-infrared spectral photoresponse at room temperature. The peak responsivity R{sub ?} and specific detectivity D{sup *} are 0.055?A/W and 5.482?×?10{sup 8}?cm·Hz{sup 1/2}/W at ??=?4.7??m under zero-bias photovoltaic mode. Temperature-dependent photoresponse measurements show abnormal intensity variation below ?200?K. Possible reasons for this phenomenon are also discussed.

  7. Optical nonlinear absorption characteristics of Sb{sub 2}Se{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Muralikrishna, Molli, E-mail: muralikrishnamolli@sssihl.edu.in; Kiran, Aditha Sai, E-mail: muralikrishnamolli@sssihl.edu.in; Ravikanth, B., E-mail: muralikrishnamolli@sssihl.edu.in; Sowmendran, P., E-mail: muralikrishnamolli@sssihl.edu.in; Muthukumar, V. Sai, E-mail: muralikrishnamolli@sssihl.edu.in; Venkataramaniah, Kamisetti, E-mail: muralikrishnamolli@sssihl.edu.in [Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam-515 134 (India)

    2014-04-24T23:59:59.000Z

    In this work, we report for the first time, the nonlinear optical absorption properties of antimony selenide (Sb{sub 2}Se{sub 3}) nanoparticles synthesized through solvothermal route. X-ray diffraction results revealed the crystalline nature of the nanoparticles. Electron microscopy studies revealed that the nanoparticles are in the range of 10 - 40 nm. Elemental analysis was performed using EDAX. By employing open aperture z-scan technique, we have evaluated the effective two-photon absorption coefficient of Sb{sub 2}Se{sub 3} nanoparticles to be 5e-10 m/W at 532 nm. These nanoparticles exhibit strong intensity dependent nonlinear optical absorption and hence could be considered to have optical power limiting applications in the visible range.

  8. Magnetism in La?O?(Fe??xMnx)?Se? tuned by Fe/Mn ratio

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

    Lei, Hechang; Bozin, Emil S.; Llobet, A.; Ivanovski, V.; Koteski, V.; Belosevic-Cavor, J.; Cekic, B.; Petrovic, C.

    2012-09-01T23:59:59.000Z

    We report the evolution of structural and magnetic properties in La?O?(Fe??xMnx)?Se?. Heat capacity and bulk magnetization indicate an increased ferromagnetic component of the long-range magnetic order and possible increased degree of frustration. Atomic disorder on Fe(Mn) sites suppresses the temperature of the long-range order whereas intermediate alloys show a rich magnetic phase diagram.

  9. A inevitabilidade de um sismo em Lisboa, s no se sabendo

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    ALTO RISCO SÍSMICO EM LISBOA · A inevitabilidade de um sismo em Lisboa, só não se sabendo a data.balasteiro@sol.pt O SOL fez uma ronda pela capital, acompanhado por especialistas: em caso de sismo, muitos hospitais prô- i ximo sismo de gran- I des dimensões em I Lisboa - uma certe- z a científica, segun- do os

  10. High-Temperature Order/Disorder Transition in the Thermoelectric Cu3SbSe3

    SciTech Connect (OSTI)

    Kirkham, Melanie J [ORNL; Majsztrik, Paul W [ORNL; Skoug, Eric [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing; Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Payzant, E Andrew [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01T23:59:59.000Z

    We report the results from an investigation into the structural evolution of a potential new thermoelectric material, Cu3SbSe3, as a function of temperature from 25 to 390 C. From high-temperature X-ray diffraction data, the refined lattice parameters were seen to change non-linearly, but continuously, with temperature, with an increased rate of thermal expansion in the a and b lattice parameters from around 125 C until around 175 C and negative thermal expansion in the c axis from around 100 C until around 175 C. Crystallographic charge flipping analysis indicated an increase in the disorder of the copper cations with temperature. This reversible order/disorder phase transition in Cu3SbSe3 affects the transport properties, as evidenced by thermal diffusivity measurements, which change from negative to positive slope at the transition temperature. This structural change in Cu3SbSe3 has implications for its potential use in thermoelectric generators.

  11. The thermally stimulated conductivity in amorphous thin film As?Se?

    E-Print Network [OSTI]

    Bryant, John Duffie

    1972-01-01T23:59:59.000Z

    V with a 14 -3 density of 9. 73 x 10 cm . The thermal velocity of the carriers 6 -18 was 6. 34 x 10 cm/sec, and the capture cross section was 2. 7 x 10 2 cm . These results indicate that the Nett-Davis model is more ap- plicable to amorphous As Se... II-3 Sample Holder Design (not to scale) 15 16 17 11-4 Output Curve for Chromel-Constantan Thermo- couple (Voltage vs. Temperature) (ref. 29) 19 II-5 System Cooling Curve (Temperature vs. Time) 20 II-6 System Heating Curve for a Constant Heater...

  12. Ann bay lodyans 10 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 10 se Bryant Freeman (“Tonton Liben”) ki pare ti liv sa a 2000 by Bryant C. Freeman, ed. This work has been made available by the University of Kansas Libraries’ Office of Scholarly... Freeman (“Tonton Liben”) ki pare ti liv sa a. [Lawrence, Kan.] : Institute of Haitian Studies ; [Port-au-Prince] : Bon Nouvèl : Fondasyon Alfa Lwès, 2000. Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml Tl CHENN LO A Te gen yon nonm ki te...

  13. Network Rigidity in GeSe2 Glass at High Pressure

    SciTech Connect (OSTI)

    Antao,S.; Benmore , C.; Li, B.; Wang, L.; Bychkov, E.; Parise, J.

    2008-01-01T23:59:59.000Z

    Acoustic measurements using synchrotron radiation have been performed on glassy GeSe2 up to pressures of 9.6 GPa. A minimum observed in the shear-wave velocity, associated anomalous behavior in Poisson's ratio, and discontinuities in elastic moduli at 4 GPa are indicative of a gradual structural transition in the glass. This is attributed to a network rigidity minimum originating from a competition between two densification mechanisms. At pressures up to 3 GPa, a conversion from edge- to corner-sharing tetrahedra results in a more flexible network. This is contrasted by a gradual increase in coordination number with pressure, which leads to an overall stiffening of the glass.

  14. Giant increase in critical current density of KxFe2-ySe? single crystals

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

    Lei, Hechang; Petrovic, C.

    2011-12-01T23:59:59.000Z

    The critical current density Jabc of KxFe2-ySe? single crystals can be enhanced by more than one order of magnitude, up to ~2.1×10? A/cm² by the post annealing and quenching technique. A scaling analysis reveals the universal behavior of the normalized pinning force as a function of the reduced field for all temperatures, indicating the presence of a single vortex pinning mechanism. The main pinning sources are three-dimensional (3D) point-like normal cores. The dominant vortex interaction with pinning centers is via spatial variations in critical temperature Tc (“?Tc pinning”).

  15. The thermally stimulated conductivity in amorphous thin film As?Se

    E-Print Network [OSTI]

    Bryant, John Duffie

    1972-01-01T23:59:59.000Z

    V with a 14 -3 density of 9. 73 x 10 cm . The thermal velocity of the carriers 6 -18 was 6. 34 x 10 cm/sec, and the capture cross section was 2. 7 x 10 2 cm . These results indicate that the Nett-Davis model is more ap- plicable to amorphous As Se... II-3 Sample Holder Design (not to scale) 15 16 17 11-4 Output Curve for Chromel-Constantan Thermo- couple (Voltage vs. Temperature) (ref. 29) 19 II-5 System Cooling Curve (Temperature vs. Time) 20 II-6 System Heating Curve for a Constant Heater...

  16. Nanosecond switching in GeSe phase change memory films by atomic force microscopy

    SciTech Connect (OSTI)

    Bosse, James L.; Huey, Bryan D., E-mail: bhuey@ims.uconn.edu [Department of Materials Science and Engineering, 97 North Eagleville Road, Unit 3136, Storrs, Connecticut 06269-3136 (United States); Grishin, Ilya; Kolosov, Oleg V. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Gyu Choi, Yong [Department of Materials Science and Engineering, Korea Aerospace University, Goyang-si, Gyeonggi-do, 412-791 (Korea, Republic of); Cheong, Byung-ki; Lee, Suyoun [Electronic Materials Research Center, Korea Institute of Science and Technology, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-02-03T23:59:59.000Z

    Nanosecond scale threshold switching is investigated with conducting atomic force microscopy (AFM) for an amorphous GeSe film. Switched bits exhibit 2–3 orders of magnitude variations in conductivity, as demonstrated in phase change based memory devices. Through the nm-scale AFM probe, this crystallization was achieved with pulse durations of as low as 15?ns, the fastest reported with scanning probe based methods. Conductance AFM imaging of the switched bits further reveals correlations between the switched volume, pulse amplitude, and pulse duration. The influence of film heterogeneities on switching is also directly detected, which is of tremendous importance for optimal device performance.

  17. Ann bay lodyans 7 / se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01T23:59:59.000Z

    ("Tonton Liben") ki pare ti liv sa a. AYITI SE PEP AYISYEN PM 7854 .H39 A56 Enstiti Etid Ayisyen - Inivesite Kannzas Bon Nouvel Fondasyon Alfa Lwes 1997 MALIS AP VANN, WA AP PRAN Yon jou yon neg t ap fe yon ti vizit lakay Malis. Pandan li t ap... I ak nan lespri I, ti lanp sa a ap pemet li we sot isit rive nan Ginen, menm anndan yon kay ki femen ak mi." Neg la mande: "Eske ou te seye sa deja?" Malis reponn: "O non, monche! Eske ou kwe m ta ka rete konsa jis pou m ka fe jouda, fouye lavi...

  18. Neutron Scattering Study on spin dynamics in superconducting (TlRb)2Fe4Se5

    SciTech Connect (OSTI)

    Chi, Songxue [ORNL; Ye, Feng [ORNL; Bao, Wei [Renmin University of China; Fang, Dr. Minghu [Zhejiang University; Wang, H.D. [Zhejiang University; Dong, C.H. [Zhejiang University; Savici, Andrei T [ORNL; Granroth, Garrett E [ORNL; Stone, Matthew B [ORNL; Fishman, Randy Scott [ORNL

    2013-01-01T23:59:59.000Z

    Spin dynamics in superconducting (Tl,Rb)2Fe4Se5 was investigated using the inelastic neutron scattering technique. Spin wave branches that span an energy range from 6.5 to 209 meV are success- fully described by a Heisenberg model whose dominant interactions include only the in-plane nearest (J1 and J0 1) and next nearest neighbor (J2 and J0 2) exchange terms within and between the tetramer spin blocks, respectively. These exchange constants, experimentally determined in this work, would crucially constrain the diverse theoretical viewpoints on magnetism and superconductivity in the Fe-based materials.

  19. PHaSE | U.S. DOE Office of Science (SC)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeeding access toTest andOptimize832 2.860SelectedGLOWAGREEMENTPHaSE Energy

  20. DISSERTATION IMPACT OF SECONDARY BARRIERS ON CuIn1-xGaxSe2 SOLAR-CELL

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION IMPACT OF SECONDARY BARRIERS ON CuIn1-xGaxSe2 SOLAR-CELL OPERATION Submitted by Alexei Impact of Secondary Barriers on CuIn1-xGaxSe2 Solar-Cell Operation Thin-film solar cells based on CuInSe2 layers in p-n junctions of CIGS solar cells often improve photodiode properties of the devices. Several

  1. Investigation of polycrystalline thin-film CuInSe{sub 2} solar cells based on ZnSe windows. Annual subcontract report, 15 Febraury 1992--14 February 1993

    SciTech Connect (OSTI)

    Olsen, L C [Washington State Univ. at Tri-Cities, Richland, WA (United States)

    1994-05-01T23:59:59.000Z

    Investigations of ZnSe/CIS solar cells are being carried out in an effort to improve the efficiencies CIS cells and to determine if ZnSe is a viable alternative to CdS as a window material. MOCVD growth of ZnSe is accomplished in a SPIRE 500XT reactor housed in the Electronic Materials Laboratory at WSU Tri-Cities by reacting a zinc adduct with H{sub 2}Se. Conductive n-type ZnSe is grown by using iodine as a dopant. Ethyliodide was mixed with helium and installed on one of the gas lines to the system. ZnSe films have been grown on CIS substrates at 200{degrees}C to 250{degrees}C. ZnO is also being deposited by MOCVD by reacting tetrahydrofuran (THF) with a zinc adduct. ZnSe/CIS heterojunctions have been studied by growing n-ZnSe films onto 2 cm x 2 cm CIS substrates diced from materials supplied by Siemens and then depositing an array of aluminum circular areas 2.8.mm in diameter on top of the ZnSe to serve as contacts. Al films are deposited with a thickness of 80 to l00 {angstrom}so that light can pass through the film, thus allowing the illuminated characteristics of the ZnSe/CIS junction to be tested. Accounting for the 20 to 25 % transmittance through the Al film into the ZnSe/CIS structure, current devices have estimated, active-area AM1.5 efficiencies of 14 %. Open circuit voltages > 500 mV are often attained.

  2. Characterization and device performance of (AgCu)(InGa)Se2 absorber layers

    SciTech Connect (OSTI)

    Hanket, Gregory; Boyle, Jonathan H.; Shafarman, William N.

    2009-06-08T23:59:59.000Z

    The study of (AgCu)(InGa)Se2 absorber layers is of interest in that Ag-chalcopyrites exhibit both wider bandgaps and lower melting points than their Cu counterparts. (AgCu)(InGa)Se2 absorber layers were deposited over the composition range 0 < Ag/(Ag+Cu) < 1 and 0.3 < Ga/(In+Ga) < 1.0 using a variety of elemental co-evaporation processes. Films were found to be singlephase over the entire composition range, in contrast to prior studies. Devices with Ga content 0.3 < Ga/(In+Ga) <0.5 tolerated Ag incorporation up to Ag/(Ag+Cu) = 0.5 without appreciable performance loss. Ag-containing films with Ga/(In+Ga) = 0.8 showed improved device characteristics over Cu-only control samples, in particular a 30-40% increase in short-circuit current. An absorber layer with composition Ag/(Ag+Cu) = 0.75 and Ga/(In+Ga) = 0.8 yielded a device with VOC = 890 mV, JSC = 20.5mA/cm2, fill factor = 71.3%, and ? = 13.0%.

  3. Effect of Ligands on Characteristics of (CdSe)13 Quantum Dot

    SciTech Connect (OSTI)

    Gao, Yang; Zhou, Bo; Kang, Seung-gu; Xin, Minsi; Yang, Ping; Dai, Xing; Wang, Zhigang; Zhou, Ruhong

    2014-01-01T23:59:59.000Z

    The widespread applications of quantum dots (QDs) have spurred an increasing interest in the study of their coating ligands, which can not only protect the electronic structures of the central QDs, but also control their permeability through biological membranes with both size and shape. In this work, we have used density functional theory (DFT) to investigate the electronic structures of (CdSe)13 passivated by OPMe2(CH2)nMe ligands with different lengths and various numbers of branches (Me=methyl group, n = 0, 1-3). Our results show that the absorption peak in the ultraviolet-visible (UV-vis) spectra displays a clear blue-shift, on the scale of ~100 nm, upon the binding of ligands. Once the total number of ligands bound with (CdSe)13 reached a saturated number (9 or 10), no more blue-shift occurred in the absorption peak in the UV-vis spectra. On the other hand, the aliphatic chain length of ligands has a negligible effect on the optical properties of the QD core. Analyses of the bonding characteristics confirm that optical transitions are dominantly governed by the central QD core rather than the organic passivation. Interestingly, the density of states (DOS) share similar characteristics as vibrational spectra, even though there is no coordination vibration mode between the ligands and the central QD. These findings might provide insights on the material design for the passivation of quantum dots for biomedical applications.

  4. The role of ligands in the optical and electronic spectra of CdSe nanoclusters

    SciTech Connect (OSTI)

    Kilina, Svletana [Los Alamos National Laboratory; Sergei, Ivanov A [Los Alamos National Laboratory; Victor, Klimov I [Los Alamos National Laboratory; Sergei, Tretiak [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    We investigate the impact of ligands on morphology, electronic structure, and optical response of the Cd33Se33 cluster, which already overlapps in size with the smallest synthesized CdSe quantum dots (QDs). Our Density Functional Theory (DFT) calculations demonstrate significant surface reorganization both for the bare cluster and for the cluster capped by amine and phosphine oxide ligand models. We observe strong surface-ligand interactions leading to substantial charge redistribution and polarization effects on the surface. This effect results in the appearance of hybridized states, where the electronic density is spread over the cluster and the ligands. Neither the ligand's nor hybridized molecular orbitals appear as trap states inside or near the band gap of the QD. Instead, being optically dark, dense hybridized states from the edges of the valence and the conduction bands could open new relaxation channels for high energy photoexcitations. Comparing quantum dots passivated by different ligands, we found that hybridized states are denser in at the edge of the conduction band of the cluster ligated with phosphine oxide molecules than that with primary amines. Such a different manifestation of ligand binding may potentially lead to the faster electron relaxation in dots passivated by phosphine oxide than by amine ligands, which is in agreement with experimental data.

  5. Structure determination of the high-pressure phase of CdSe

    SciTech Connect (OSTI)

    Li, Yanchun, E-mail: liyc@ihep.ac.cn, E-mail: liuj@ihep.ac.cn; Lin, Chuanlong; Li, Xiaodong; Liu, Jing, E-mail: liyc@ihep.ac.cn, E-mail: liuj@ihep.ac.cn [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, 100049 Beijing (China); Li, Gong [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Xu, Jian [Institute of Fluid Physics, China Academy of Engineering Physics, P. O. Box 919-102, Mianyang, Sichuan 621900 (China)

    2014-06-14T23:59:59.000Z

    Structural phase transition sequence of CdSe has been investigated at pressures up to 60?GPa under quasi-hydrostatic conditions using synchrotron X-ray diffraction. A phase transition from the wurtzite type (B4) to the NaCl-type (B1) structure has been observed, followed by another phase transition to an orthorhombic structure at 27?GPa, in agreement with previous reports. We show that this high-pressure orthorhombic phase has a Pnma symmetry rather than being a Cmcm-symmetric structure as previously suggested. From our observations, the appearance of the new reflections and reflection splitting with increasing pressure is due to the change of atomic relative positions in crystal lattice and the difference in the compression ratio of lattice parameters for the Pnma structure, and we find no evidence for the third phase transition reported previously. The pressure-induced phase transition of CdSe has been further confirmed by the density-functional theory calculations.

  6. Polytypism, polymorphism, and superconductivity in TaSe2-xTex

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

    Luo, Huixia; Tao, Jing; Xie, Weiwei; Inoue, Hiroyuki; Gyenis, Andras; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, R. J.

    2015-03-17T23:59:59.000Z

    Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO? are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivitymore »of TaSe?, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe2-xTex solid solution, and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. The reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of Tc on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.« less

  7. Dependence of superconductivity in CuxBi?Se? on quenching conditions

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

    Schneeloch, J. A.; Zhong, R. D.; Xu, Z. J.; Gu, G. D.; Tranquada, J. M.

    2015-04-01T23:59:59.000Z

    Topological superconductivity, implying gapless protected surface states, has recently been proposed to exist in the compound CuxBi?Se?. Unfortunately, low diamagnetic shielding fractions and considerable inhomogeneity have been reported in this compound. In an attempt to understand and improve on the finite superconducting volume fractions, we have investigated the effects of various growth and post-annealing conditions. With a melt-growth (MG) method, diamagnetic shielding fractions of up to 56% in Cu???Bi?Se? have been obtained, the highest value reported for this method. We investigate the efficacy of various quenching and annealing conditions, finding that quenching from temperatures above 560°C is essential for superconductivity,more »whereas quenching from lower temperatures or not quenching at all is detrimental. A modified floating zone (FZ) method yielded large single crystals but little superconductivity. Even after annealing and quenching, FZ-grown samples had much less chance of being superconducting than MG-grown samples. From the low shielding fractions in FZ-grown samples and the quenching dependence, we suggest that a metastable secondary phase having a small volume fraction in most of the samples may be responsible for the superconductivity.« less

  8. SeZnSb alloy and its nano tubes, graphene composites properties

    SciTech Connect (OSTI)

    Singh, Abhay Kumar [Department of Physics, Indian Institute of Physics, Bangalore-560012 (India)

    2013-04-15T23:59:59.000Z

    Composite can alter the individual element physical property, could be useful to define the specific use of the material. Therefore, work demonstrates the synthesis of a new composition Se{sub 96}-Zn{sub 2}-Sb{sub 2} and its composites with 0.05% multi-walled carbon nano tubes and 0.05% bilayer graphene, in the glassy form. The diffused amorphous structure of the multi walled carbon nano tubes and bilayer gaphene in the Se{sub 96}-Zn{sub 2}-Sb{sub 2} alloy have been analyzed by using the Raman, X-ray photoluminescence spectroscopy, Furrier transmission infrared spectra, photoluminescence, UV/visible absorption spectroscopic measurements. The diffused prime Raman bands (G and D) have been appeared for the multi walled carbon nano tubes and graphene composites, while the X-ray photoluminescence core energy levels peak shifts have been observed for the composite materials. Subsequently the photoluminescence property at room temperature and a drastic enhancement (upto 80%) in infrared transmission percentage has been obtained for the bilayer graphene composite, along with optical energy band gaps for these materials have been evaluated 1.37, 1.39 and 1.41 eV.

  9. alta verapaz guatemala: Topics by E-print Network

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

    de Computacion Cientifica y Programacion Paralela http:luna.inf.um.esgrupo investigacion San Alberto, 14 noviembre 2014 Computacion de Altas Prestaciones San...

  10. Unearthing Collaboration: Community and Multivocal Archaeology in Highland Guatemala

    E-Print Network [OSTI]

    Kraemer, Anne

    2008-05-13T23:59:59.000Z

    became impossible because the archaeological site is located directly beneath the town. Excavation and reconnaissance required permission to enter corn fields, cow pastures, and even personal homestead property. Without the agreement of the community.... All humans assign meaning to material culture. It is within this unique aspect of human nature that worldviews collide and from which collaboration can emerge. Archaeology has the potential to also hurt, judge, and damage living peoples. ?Once...

  11. An overview of the poultry industry of Guatemala

    E-Print Network [OSTI]

    Braly Lopez, Esther Yvette

    1989-01-01T23:59:59.000Z

    coloring in it so that the workers could tell which eggs had been disinfected. The yellow dye was made from a vegetable thai contains some oil ?and the egg shel 1 pores and equipment were being clogged. The company claimed that there had been a decrease...

  12. Guatemala-Enhancing Capacity for Low Emission Development Strategies

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI ReferenceJumpEnergy InformationGrupo Urbas(EC-LEDS) | Open

  13. Guatemala-IAEA Energy Planning | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI ReferenceJumpEnergy InformationGrupo Urbas(EC-LEDS) |

  14. Guatemala-USAID Climate Activities | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI ReferenceJumpEnergy InformationGrupo Urbas(EC-LEDS) ||

  15. Guatemala-Enhancing Capacity for Low Emission Development Strategies...

    Open Energy Info (EERE)

    Costa Rica, Gabon, Indonesia, Kenya, Macedonia, Mexico, Moldova, the Philippines, Serbia, and Vietnam. Fact Sheet EC-LEDSfactsheet.pdf References "EC-LEDS" Retrieved...

  16. Guatemala-Joint Programme on Resource Efficient and Cleaner Production

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG| Open Energy InformationGettop Science Technology Co LtdCorp(RECP)

  17. Guatemala-UNEP Risoe Technology Needs Assessment Program | Open Energy

    Open Energy Info (EERE)

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

  18. Planar waveguide obtained by burying a Ge22As20Se58 fiber in As2S3 glass

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Planar waveguide obtained by burying a Ge22As20Se58 fiber in As2S3 glass Quentin Coulombier glasses. Two highly mature chalcogenide glasses are used for these experiments. GASIR glass from Umicore IR Glass, Olen, Belgium, with the composition of Ge22As20Se58 is used to draw fibers

  19. CoSe2 Nanoparticles Grown on Carbon Fiber Paper: An Efficient and Stable Electrocatalyst for Hydrogen Evolution Reaction

    E-Print Network [OSTI]

    Cui, Yi

    are designed to function in acidic electrolyte, in which the state- of-the-art hydrogen-producing catalystsCoSe2 Nanoparticles Grown on Carbon Fiber Paper: An Efficient and Stable Electrocatalyst-dimensional electrodes composed of CoSe2 nanoparticles grown on carbon fiber paper. The electrode exhibits excellent

  20. Hydrogen passivation of Se and Te in AlSb M. D. McCluskey and E. E. Haller

    E-Print Network [OSTI]

    McCluskey, Matthew

    Hydrogen passivation of Se and Te in AlSb M. D. McCluskey and E. E. Haller Lawrence Berkeley observed local vibrational modes LVM's arising from DX-hydrogen complex in AlSb. Hydrogen was diffused into bulk AlSb:Se and AlSb:Te by annealing in sealed quartz ampoules with either hydrogen gas or methanol CH

  1. Absorption spectra of CdSe-ZnS core-shell quantum dots at high photon energies : experiment and modeling

    E-Print Network [OSTI]

    Ghosh, Sandip

    Absorption spectra of CdSe-ZnS core-shell quantum dots at high photon energies : experiment spectra of CdSe-ZnS core-shell quantum dot (QD) ensembles, with average core diameters ranging from 2.6 nm. In agreement with previous reports, the absorption coefficient at energies 1 eV above the effective bandgap

  2. Metastability in Pressure-Induced Structural Transformations of CdSe/ZnS Core/Shell Nanocrystals

    E-Print Network [OSTI]

    Rabani, Eran

    . In nanocrystals with thick shells, we furthermore observe a wurtzite to NiAs transformation, which does not occur on particles' size and shape.2-6 The wurtzite to rocksalt transformation in CdSe nanocrystals, for example wurtzite CdSe nanocrystals of 3 nm diameter (500 atoms), that have been epitaxially passivated with Zn

  3. Viscosity and radial distribution function in PbxSe(1-x) melts for stoechiometric and peritectic compositions

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    L-529 Viscosity and radial distribution function in PbxSe(1-x) melts for stoechiometric by lead atoms sur- rounded by Se atoms are considered. Kinematic viscosity data are compared a molecular structure in the liquid state rather than a chain-structure [1]. Viscosity is very sensitive

  4. Atomic structures and electronic properties of 2H-NbSe{sub 2}: The impact of Ti doping

    SciTech Connect (OSTI)

    Li, Hongping, E-mail: hpli@mail.ujs.edu.cn, E-mail: zcwang@wpi-aimr.tohoku.ac.jp; Chen, Lin; Zhang, Kun; Liang, Jiaqing; Tang, Hua; Li, Changsheng [Institute for Advanced Materials, School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Liu, Xiaojuan; Meng, Jian [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Wang, Zhongchang, E-mail: hpli@mail.ujs.edu.cn, E-mail: zcwang@wpi-aimr.tohoku.ac.jp [Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-09-14T23:59:59.000Z

    Layered transition metal dichalcogenides have aroused renewed interest as electronic materials, yet their electronic performances could be modified by chemical doping. Here, we perform a systematic first-principles calculation to investigate the effect of Ti doping on atomic structure and electronic properties of the 2H-NbSe{sub 2}. We consider a total of three possible Ti-doping models and find that both the substitution and intercalated models are chemically preferred with the intercalation model being more favorable than the substitution one. Structural analyses reveal a slight lattice distortion triggered by Ti doping, but the original structure of 2H-NbSe{sub 2} is maintained. We also observe an expansion of c axis in the substituted model, which is attributed to the reduced van der Waals interaction arising from the increased Se-Se bond length. Our calculations also predict that the electron transport properties can be enhanced by the Ti doping, especially for the Ti-intercalated 2H-NbSe{sub 2}, which should be beneficial for the realization of superconductivity. Furthermore, the covalence element is found in the Ti-Se bonds, which is ascribed to the hybridization of Ti 3d and Se 4p orbitals. The findings indicate that doping of transition metals can be regarded as a useful way to tailor electronic states so as to improve electron transport properties of 2H-NbSe{sub 2}.

  5. RUNNING HEAD: Subaerial Exposure Unconformities on the Vercors Carbonate Platform Subaerial Exposure Unconformities on the Vercors Carbonate Platform (SE France)

    E-Print Network [OSTI]

    Fouke, Bruce W.

    1 RUNNING HEAD: Subaerial Exposure Unconformities on the Vercors Carbonate Platform Subaerial Exposure Unconformities on the Vercors Carbonate Platform (SE France) and their Sequence Stratigraphic carbonate platform (SE France), shows that the most prominent break in depositional style does not coincide

  6. Optical and quantum efficiency analysis of (Ag,Cu)(In,Ga)Se2 absorber layers

    SciTech Connect (OSTI)

    Boyle, Jonathan; Hanket, Gregory; Shafarman, William

    2009-06-09T23:59:59.000Z

    (Ag,Cu)(In,Ga)Se2 thin films have been deposited by elemental co-evaporation over a wide range of compositions and their optical properties characterized by transmission and reflection measurements and by relative shift analysis of quantum efficiency device measurements. The optical bandgaps were determined by performing linear fits of (?h?)2 vs. h?, and the quantum efficiency bandgaps were determined by relative shift analysis of device curves with fixed Ga/(In+Ga) composition, but varying Ag/(Cu+Ag) composition. The determined experimental optical bandgap ranges of the Ga/(In+Ga) = 0.31, 0.52, and 0.82 groups, with Ag/(Cu+Ag) ranging from 0 to 1, were 1.19-1.45 eV, 1.32-1.56 eV, and 1.52-1.76 eV, respectively. The optical bowing parameter of the different Ga/(In+Ga) groups was also determined.

  7. Environmental issues related to commercialization of CulnSe{sub 2}- based photovoltaics

    SciTech Connect (OSTI)

    Eberspacher, C. [UNISUN, Newbury Park, CA (United States); Fthenakis, V.M.; Moskowitz, P.D.

    1996-07-01T23:59:59.000Z

    One of the most promising materials for low-cost thin film photovoltaic cells is copper indium selenide (CuInSe{sub 2} or CIS). As with any new material, successful commercialization of CIS photovoltaic (PV) technology will require attention to environmental issues related to the sources of raw materials, their usage, and the disposal and/or recycling of products at the end of their useful life. This paper focuses on three specific environmental issues related to CIS technology: (i) Economics of the use and re-use of materials; (ii) regulations on environmental disposal and waste handling, and (iii) logistics and economics of recycling and disposing of products by industries faced with comparable environmental issues.

  8. The surface-state of the topological insulator Bi2Se3 revealed by cyclotron resonance

    SciTech Connect (OSTI)

    Mcdonald, Ross D [Los Alamos National Laboratory; Ayala - Valenzuela, Oscar E [Los Alamos National Laboratory; Altarawneh, Moaz M [Los Alamos National Laboratory; Analytis, James G [STANFORD UNIV/SLAC; Chu, J. H. [STANFORD UNIV/SLAC; Fisher, R. [STANFORD UNIV/SLAC

    2011-01-14T23:59:59.000Z

    Transport measurements of topological insulators are dominated by the conductivity of the bulk, leading to substantial difficulties in resolving the properties of the surface. To this end, we use high magnetic field, rf- and microwave-spectroscopy to selectively couple to the surface conductivity of Bi2Se3 at high frequency. In the frequency range of a few GHz we observe a crossover from quantum oscillations indicative of a small 3D Fermi surface, to cyclotron resonance indicative of a 2D surface state. By probing the conductivity at reduced skin depths, we have observed a 2D cyclotron resonance from a material whose bulk Fermi-surface is 3D. The frequency-magnetic field scaling of this resonance is inconsistent with the bulk effective mass, but more consistent with the dispersion and band filling of a Dirac-like surface state as observed by ARPES, with substantial manybody renormalization.

  9. Doping Effects on the Thermoelectric Properties of Cu3SbSe4

    SciTech Connect (OSTI)

    Skoug, Eric [Michigan State University, East Lansing; Cain, Jeffrey D. [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing; Majsztrik, Paul W [ORNL; Kirkham, Melanie J [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01T23:59:59.000Z

    We present the first systematic doping study on the ternary semiconductor Cu3SbSe 4 . We have developed a novel synthesis procedure that produces high-quality polycrystalline samples with hole concentrations an order of magnitude lower than have been reported for the undoped compound. The hole concentration can be increased by adding small amounts of either Ge or Sn on the Sb site. The power factor increases with increasing doping, reaching a maximum value of 16 W/cmK^2 . The thermoelectric properties are optimized for the 2% Sn doped compound which has ZT=0.72 at 630K, rivaling that of state-of-the-art thermoelectric materials in this temperature range.

  10. Energy levels and radiative transition rates for Ge XXXI, As XXXII, and Se XXXIII

    SciTech Connect (OSTI)

    Aggarwal, Sunny, E-mail: sunny.du87@gmail.com; Singh, J.; Jha, A.K.S.; Mohan, Man

    2014-07-15T23:59:59.000Z

    Fine-structure energies of the 67 levels belonging to the 1s{sup 2}, 1s 2l, 1s3l, 1s4l, 1s5l, and 1s6l configurations of Ge XXXI, As XXXII, and Se XXXIII have been calculated using the General-Purpose Relativistic Atomic Structure Package. In addition, radiative rates, oscillator strengths, transition wavelengths, and line strengths have been calculated for all electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among these levels. Lifetimes are also presented for all excited levels of these three ions. We have compared our results with the results available in the literature and the accuracy of the data is assessed. We predict new energy levels, oscillator strengths, and transition probabilities where no other theoretical or experimental results are available, which will form the basis for future experimental work.

  11. One-volt p-InP/n-CdSe regenerative photoelectrochemical cell

    SciTech Connect (OSTI)

    Ang, P.G.P.; Sammells, A.F.

    1983-08-01T23:59:59.000Z

    Features and performance of a two-photoelectrode regenerative photoelectrochemical (PEC) cell that yielded a combined photovoltage of more than one volt are reported. The photoanode was n-CdSe, the photocathode was p-InP, and the electrolyte was aqueous sulfide/polysulfide. Details of the fabrication process are provided, including formation of an ohmic contact by sputter deposited gold and then electroplating the photocathode with Zn, followed by a final sputtered gold layer. Tests under 100 mW/sq cm illumination of the unoptimized regenerative cell produced an open circuit voltage of 1.15 V, a short circuit current of 24 mA/sq cm, a fill factor of 0.40, and an overall efficiency of 5.5 percent.

  12. Characterization of Se-loaded molecular sieves A, X, Y, AlPO-5, and mordenite

    SciTech Connect (OSTI)

    Parise, J.B.; MacDougall, J.E.; Herron, N.; Farlee, R.; Sleight, A.W.; Ying Wang; Bein, T.; Moller, K.; Moroney, L.M.

    1988-01-27T23:59:59.000Z

    Selenium has been successfully loaded into molecular sieves A, X, Y, AlPO-5, and mordenite, and the products were characterized by using EXAFS, solid-state NMR, and diffuse-reflectance techniques. This study reveals selenium is predominantly of the trigonal (helical chains) form in all but the A sample, where only the Se/sub 8/-crown ring form is found. A mixture of allotropes and helical chains occupy the large 3D-pore and channel systems of molecular sieves X and Y; however, a single, probably fixed-pitch helical-chain allotrope occupies the more constrained 12-membered-ring channels found in mordenite and AlPO-5. The high degree of order in these last two sieves is reflected in a strong second-shell feature in the EXAFS spectra. 22 refs., 12 figs., 3 tabs.

  13. Nuclear Structure Relevant to Neutrinoless Double {beta} Decay: {sup 76}Ge and {sup 76}Se

    SciTech Connect (OSTI)

    Schiffer, J. P.; Gros, S.; Jiang, C. L.; Rehm, K. E. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Freeman, S. J.; Fitzpatrick, C. R.; Kay, B. P. [University of Manchester, Manchester M13 9PL (United Kingdom); Clark, J. A.; Deibel, C.; Heinz, A.; Parikh, A.; Parker, P. D.; Werner, V.; Wrede, C. [Yale University, New Haven, Connecticut 06520 (United States); Hirata, D. [GANIL (IN2P3/CNRS -DSM/CEA), B.P. 55027 14076 Caen Cedex 5 (France); Dept. of Physics and Astronomy, Open University, Milton Keynes, MK7 6AA (United Kingdom); Villari, A. C. C. [GANIL (IN2P3/CNRS -DSM/CEA), B.P. 55027 14076 Caen Cedex 5 (France)

    2008-03-21T23:59:59.000Z

    The possibility of observing neutrinoless double {beta} decay offers the opportunity of determining the effective neutrino mass if the nuclear matrix element were known. Theoretical calculations are uncertain, and measurements of the occupations of valence orbits by nucleons active in the decay can be important. The occupation of valence neutron orbits in the ground states of {sup 76}Ge (a candidate for such decay) and {sup 76}Se (the daughter nucleus) were determined by precisely measuring cross sections for both neutron-adding and removing transfer reactions. Our results indicate that the Fermi surface is much more diffuse than in theoretical calculations. We find that the populations of at least three orbits change significantly between these two ground states while in the calculations, the changes are confined primarily to one orbit.

  14. Nuclear Structure Relevant to Neutrinoless Double Beta Decay: 76Ge and 76Se

    E-Print Network [OSTI]

    J. P. Schiffer; S. J. Freeman; J. A. Clark; C. Deibel; C. R. Fitzpatrick; S. Gros; A. Heinz; D. Hirata; C. L. Jiang; B. P. Kay; A. Parikh; P. D. Parker; K. E. Rehm; A. C. C. Villari; V. Werner; C. Wrede

    2007-10-03T23:59:59.000Z

    The possibility of observing neutrinoless double beta decay offers the opportunity of determining the neutrino mass IF the nuclear matrix element were known. Theoretical calculations are uncertain and measurements of the occupations of valence orbits by nucleons active in the decay can be important. The occupation of valence neutron orbits in the ground states of 76Ge and 76Se were determined by precisely measuring cross sections for both neutron-adding and removing transfer reactions. Our results indicate that the Fermi surface is much more diffuse than in theoretical (QRPA) calculations. We find that the populations of at least three orbits change significantly between these two ground states while in the calculations the changes are confined primarily to one orbit.

  15. Stable n-CuInSe/sub 2/iodide-iodine photoelectrochemical cell

    DOE Patents [OSTI]

    Cahen, D.; Chen, Y.W.

    1984-09-20T23:59:59.000Z

    In a photoelectrochemical solar cell, stable output and solar efficiency in excess of 10% are achieved with a photoanode of n-CuInSe/sub 2/ electrode material and an iodine/iodide redox couple used in a liquid electrolyte. The photoanode is prepared by treating the electrode material by chemical etching, for example in Br/sub 2//MeOH; heating the etched electrode material in air or oxygen; depositing a surface film coating of indium on the electrode material after the initial heating; and thereafter again heating the electrode material in air or oxygen to oxidize the indium. The electrolyte is treated by the addition of Cu/sup +/ or Cu/sup 2 +/ salts and in In/sup 3 +/ salts.

  16. Strain-dependent photoluminescence behavior in three geometries of CdSe/CdS nanocrystals

    SciTech Connect (OSTI)

    Choi, Charina L; Koski, Kristie J; Sivasankar, Sanjeevi; Alivisatos, A Paul

    2009-05-26T23:59:59.000Z

    In recent years, a new generation of quantum confined colloidal semiconductor structures has emerged, with more complex shapes than simple quantum dots1, 2. These include nanorods3 and tetrapods4. Beyond shape, it is also now possible to spatially vary the electron and hole potentials within these nanoparticles by varying the composition. Examples of these new structures include seeded dots, rods, and tetrapods, which contain a CdSe core embedded within a CdS shell5, 6. These structures may have many uses beyond those envisioned for simple quantum dots, which are frequently employed in luminescent applications7. This paper is concerned with changes in the optoelectronic properties of tetrapods when the arms are bent. We demonstrate that seeded tetrapods can serve as an optical strain gauge, capable of measuring forces on the order of nanonewtons. We anticipate that a nanocrystal strain gauge with optical readout will be useful for applications ranging from sensitive optomechanical devices to biological force investigations.

  17. Development and characterization of PCDTBT:CdSe QDs hybrid solar cell

    SciTech Connect (OSTI)

    Dixit, Shiv Kumar, E-mail: shivkumardixit.7@gmail.com; Bhatnagar, Chhavi, E-mail: shivkumardixit.7@gmail.com; Kumari, Anita, E-mail: shivkumardixit.7@gmail.com; Madhwal, Devinder, E-mail: shivkumardixit.7@gmail.com; Bhatnagar, P. K., E-mail: shivkumardixit.7@gmail.com; Mathur, P. C., E-mail: shivkumardixit.7@gmail.com [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 (India)

    2014-10-15T23:59:59.000Z

    Solar cell consisting of low band gap polymer poly[N-900-hepta-decanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10, 30-benzothiadiazole)] (PCDTBT) as donor and cadmium selenide/zinc sulphide (CdSe/ZnS) core shell quantum dots (QDs) as an acceptor has been developed. The absorption measurements show that the absorption coefficient increases in bulk heterojunction (BHJ) structure covering broad absorption spectrum (200nm–700nm). Also, the photoluminescence (PL) of the PCDTBT:QDs film is found to decrease by an order of magnitude showing a significant transfer of electrons to the QDs. With this approach and under broadband white light with an irradiance of 8.19 mW/cm{sup 2}, we have been able to achieve a power conversion efficiency (PCE) of 3.1 % with fill factor 0.42 for our typical solar cell.

  18. Production cross sections of neutron rich isotopes from a 82Se beam

    E-Print Network [OSTI]

    Tarasov, O B; Amthor, A M; Bandura, L; Baumann, T; Bazin, D; Berryman, J S; Chubarian, G; Fukuda, N; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Pereira, J; Portillo, M; Sherrill, B M; Stolz, A; Sumithrarachchi, C; Thoennessen, M; Weisshaar, D

    2012-01-01T23:59:59.000Z

    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements $11 \\le Z \\le 32$ were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements $22 \\le Z \\le 25$ (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.

  19. Production cross sections of neutron rich isotopes from a 82Se beam

    E-Print Network [OSTI]

    O. B. Tarasov; D. J. Morrissey; A. M. Amthor; L. Bandura; T. Baumann; D. Bazin; J. S. Berryman; G. Chubarian; N. Fukuda; A. Gade; T. N. Ginter; M. Hausmann; N. Inabe; T. Kubo; J. Pereira; M. Portillo; B. M. Sherrill; A. Stolz; C. Sumithrarachchi; M. Thoennessen; D. Weisshaar

    2012-09-06T23:59:59.000Z

    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements $11 \\le Z \\le 32$ were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements $22 \\le Z \\le 25$ (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.

  20. ZnO/Cu(InGa)Se.sub.2 solar cells prepared by vapor phase Zn doping

    SciTech Connect (OSTI)

    Ramanathan, Kannan; Hasoon, Falah S.; Asher, Sarah E.; Dolan, James; Keane, James C.

    2007-02-20T23:59:59.000Z

    A process for making a thin film ZnO/Cu(InGa)Se.sub.2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se.sub.2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se.sub.2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se.sub.2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se.sub.2.

  1. Migrating data from TcSE to DOORS : an evaluation of the T-Plan Integrator software application.

    SciTech Connect (OSTI)

    Post, Debra S. (Sandia National Laboratories, Livermore, CA); Manzanares, David A.; Taylor, Jeffrey L.

    2011-02-01T23:59:59.000Z

    This report describes our evaluation of the T-Plan Integrator software application as it was used to transfer a real data set from the Teamcenter for Systems Engineering (TcSE) software application to the DOORS software application. The T-Plan Integrator was evaluated to determine if it would meet the needs of Sandia National Laboratories to migrate our existing data sets from TcSE to DOORS. This report presents the struggles of migrating data and focuses on how the Integrator can be used to map a data set and its data architecture from TcSE to DOORS. Finally, this report describes how the bulk of the migration can take place using the Integrator; however, about 20-30% of the data would need to be transferred from TcSE to DOORS manually. This report does not evaluate the transfer of data from DOORS to TcSE.

  2. ZnO/Cu(InGa)Se2 solar cells prepared by vapor phase Zn doping

    DOE Patents [OSTI]

    Ramanathan, Kannan; Hasoon, Falah S.; Asher, Sarah E.; Dolan, James; Keane, James C.

    2007-02-20T23:59:59.000Z

    A process for making a thin film ZnO/Cu(InGa)Se2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se2.

  3. Graphene oxide based CdSe photocatalysts: Synthesis, characterization and comparative photocatalytic efficiency of rhodamine B and industrial dye

    SciTech Connect (OSTI)

    Ghosh, Trisha [Department of Advanced Materials Science and Engineering, Hanseo University, Chungnam, 356-706 (Korea, Republic of); Lee, Jeong-Ho [Dasan Linc Educational Development Institute, Dankook University, Cheonan, Chungnam, 330-714 (Korea, Republic of); Meng, Ze-Da; Ullah, Kefayat; Park, Chong-Yeon; Nikam, Vikram [Department of Advanced Materials Science and Engineering, Hanseo University, Chungnam, 356-706 (Korea, Republic of); Oh, Won-Chun, E-mail: wc_oh@hanseo.ac.kr [Department of Advanced Materials Science and Engineering, Hanseo University, Chungnam, 356-706 (Korea, Republic of)

    2013-03-15T23:59:59.000Z

    Highlights: ? CdSe–graphene is synthesized by hydrothermal method. ? Three molar solutions of CdSe were used making three different composites. ? RhB and Texbrite MST-L were used as sample dye solutions. ? Texbrite MST-L is photo degraded in visible light. ? UV-spectroscopic analysis was done to measure degradation. - Abstract: CdSe–graphene composites were prepared using simple “hydrothermal method” where the graphene surface was modified using different molar solutions of cadmium selenide (CdSe) in aqueous media. The characterization of CdSe–graphene composites were studied by X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscope (SEM), and with transmission electron microscope (TEM). The catalytic activities of CdSe-composites were evaluated by degradation of rhodamine B (RhB) and commercial industrial dye “Texbrite MST-L (TXT-MST)” with fixed concentration. The degradation was observed by the decrease in the absorbance peak studied by UV spectrophotometer. The decrease in the dye concentration indicated catalytic degradation effect by CdSe–graphene composites.

  4. Single-step in-situ synthesis and optical properties of ZnSe nanostructured dielectric nanocomposites

    SciTech Connect (OSTI)

    Dey, Chirantan; Rahaman Molla, Atiar; Tarafder, Anal; Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [CSIR-Central Glass and Ceramic Research Institute, Glass Science and Technology Section, Glass Division, 196, Raja S. C. Mullick Road, 700032 Kolkata (India); Kr Mishra, Manish; De, Goutam [CSIR-Central Glass and Ceramic Research Institute, Nano-Structured Materials Division, 196, Raja S. C. Mullick Road, 700032 Kolkata (India); Goswami, Madhumita; Kothiyal, G. P. [Glass and Advanced Ceramics Division, Bhaba Atomic Research Centre, Trombay, 400085 Mumbai (India)

    2014-04-07T23:59:59.000Z

    This work provides the evidence of visible red photoluminescent light emission from ZnSe nanocrystals (NCs) grown within a dielectric (borosilicate glass) matrix synthesized by a single step in-situ technique for the first time and the NC sizes were controlled by varying only the concentration of ZnSe in glass matrix. The ZnSe NCs were investigated by UV-Vis optical absorption spectroscopy, Raman spectroscopy, and transmission electron microscopy (TEM). The sizes of the ZnSe NCs estimated from the TEM images are found to alter in the range of 2–53?nm. Their smaller sizes of the NCs were also calculated by using the optical absorption spectra and the effective mass approximation model. The band gap enlargements both for carrier and exciton confinements were evaluated and found to be changed in the range of 0–1.0?eV. The Raman spectroscopic studies showed blue shifted Raman peaks of ZnSe at 295 and 315?cm{sup ?1} indicating phonon confinement effect as well as compressive stress effect on the surface atoms of the NCs. Red photoluminescence in ZnSe-glass nanocomposite reveals a broad multiple-peak structure due to overlapping of emission from NC size related electron-hole recombination (?707?nm) and emissions from defects to traps, which were formed due to Se and Zn vacancies signifying potential application in photonics.

  5. Green route synthesis of high quality CdSe quantum dots for applications in light emitting devices

    SciTech Connect (OSTI)

    Bera, Susnata, E-mail: susnata.bera@gmail.com [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Singh, Shashi B. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Ray, S.K., E-mail: physkr@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2012-05-15T23:59:59.000Z

    Investigation was made on light emitting diodes fabricated using CdSe quantum dots. CdSe quantum dots were synthesized chemically using olive oil as the capping agent, instead of toxic phosphine. Room temperature photoluminescence investigation showed sharp 1st excitonic emission peak at 568 nm. Bi-layer organic/inorganic (P3HT/CdSe) hybrid light emitting devices were fabricated by solution process. The electroluminescence study showed low turn on voltage ({approx}2.2 V) .The EL peak intensity was found to increase by increasing the operating current. - Graphical abstract: Light emitting diode was fabricated using CdSe quantum dots using olive oil as the capping agent, instead of toxic phosphine. Bi-layer organic/inorganic (P3HT/CdSe) hybrid light emitting device shows strong electroluminescence in the range 630-661 nm. Highlights: Black-Right-Pointing-Pointer CdSe Quantum dots were synthesized using olive oil as the capping agent. Black-Right-Pointing-Pointer Light emitting device was fabricated using CdSe QDs/P3HT polymer heterojunction. Black-Right-Pointing-Pointer The I-V characteristics study showed low turn on voltage at {approx}2.2 V. Black-Right-Pointing-Pointer The EL peak intensity increases with increasing the operating current.

  6. Photodeposition of Pt on Colloidal CdS and CdSe/CdS Semiconductor Nanostructures

    SciTech Connect (OSTI)

    Dukovic, Gordana; Merkle, Maxwell G.; Nelson, James H.; Hughes, Steven M.; Alivisatos, A. Paul

    2008-08-06T23:59:59.000Z

    Semiconductor photocatalysis has been identified as a promising avenue for the conversion of solar energy into environmentally friendly fuels, most notably by the production of hydrogen from water.[1-5] Nanometer-scale materials in particular have attracted considerable scientific attention as the building blocks for light-harvesting applications.[6,7] Their desirable attributes include tunability of the optical properties with size, amenability to relatively inexpensive low-temperature processing, and a high degree of synthetic sophistication leading to increasingly complex and multi-functional architectures. For photocatalysis in particular, the high surface-to-volume ratios in nanoscale materials should lead to an increased availability of carriers for redox reactions on the nanoparticle surface. Recombination of photoexcited carriers directly competes with photocatalytic activity.[3] Charge separation is often achieved with multi-component heterostructures. An early example is the case of TiO2 powders functionalized with Pt and RuO2 particles, where photoexcited electrons are transferred to Pt (the reduction site) and holes to RuO2 (the oxidation site).[8] More recently, many colloidally synthesized nanometer-scale metal-semiconductor heterostructures have been reported.[7,9,10] A majority of these structures are made by thermal methods.[7,10] We have chosen to study photochemical formation of metal-semiconductor heterostructures. The detailed understanding of the mechanisms involved in photodeposition of metals on nanometer-scale semiconductors is necessary to enable a high degree of synthetic control. At the same time, because the results of metal deposition can be directly observed by electron microscopy, it can be used to understand how factors such as nanocrystal composition, shape, carrier dynamics, and surface chemistry influence the photochemical properties of semiconductor nanocrystals. In this communication, we report on the photodeposition of Pt on colloidal CdS and CdSe/CdS core/shell nanocrystals. Among the II-VI semiconductors, CdS is of particular interest because it has the correct band alignment for water photolysis[2] and has been demonstrated to be photocatalytically active.[11-16] We have found that the photoexcitation of CdS and CdSe/CdS in the presence of an organometallic Pt precursor leads to deposition of Pt nanoparticles on the semiconductor surface. Stark differences are observed in the Pt nanoparticle location on the two substrates, and the photodeposition can be completely inhibited by the modification of the semiconductor surface. Our results suggest that tuning of the semiconductor band structure, spatial organization and surface chemistry should be crucial in the design of photocatalytic nanostructures.

  7. Investigation into the growth and structure of thin-film solid solutions of iron-based superconductors in the FeSe{sub 0.92}-FeSe{sub 0.5}Te{sub 0.5} system

    SciTech Connect (OSTI)

    Stepantsov, E. A., E-mail: stepantsov@ns.cryst.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Kazakov, S. M.; Belikov, V. V. [Moscow State University (Russian Federation)] [Moscow State University (Russian Federation); Makarova, I. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Arpaia, R.; Gunnarsson, R.; Lombardi, F. [Chalmers University of Technology, Department of Microtechnology and Nanoscience (Sweden)] [Chalmers University of Technology, Department of Microtechnology and Nanoscience (Sweden)

    2013-09-15T23:59:59.000Z

    Thin films of FeSe{sub 0.92} and FeSe{sub 0.5}Te{sub 0.5} iron chalcogenide superconductors and solid solutions containing these components in different ratios have been grown on the surface of LaAlO{sub 3} (10 1-bar 2) crystals by pulsed laser deposition. Films of solid solutions have been deposited by simultaneous laser ablation from two targets of the FeSe{sub 0.92} and FeSe{sub 0.5}Te{sub 0.5} stoichiometric compositions onto one substrate. An X-ray diffraction study of the film structure shows that the films grown are epitaxial and their lattice parameters regularly vary with the ratio of the deposited components, which was controllably varied by changing the ablation intensities from the targets.

  8. Magnetic field induced third order susceptibility of third order harmonic generation in a ZnMgSe strained quantum well

    SciTech Connect (OSTI)

    Mark, J. Abraham Hudson, E-mail: a.john.peter@gmail.com; Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, SSM Institute of Engineering and Technology, Dindigul-624002 (India)

    2014-04-24T23:59:59.000Z

    Third order susceptibility of third order harmonic generation is investigated in a Zn{sub 0.1}Mg{sub 0.9}Se/Zn{sub 0.8}Mg{sub 0.2}Se/Zn{sub 0.1}Mg{sub 0.9}Se quantum well in the presence of magnetic field strength. The confinement potential is considered as the addition of energy offsets of the conduction band (or valence band) and the strain-induced potential in our calculations. The material dependent effective mass is followed throughout the computation because it has a high influence on the electron energy levels in low dimensional semiconductor systems.

  9. Photosensitivity of pulsed laser deposited Ge{sub 20}As{sub 20}Se{sub 60} and Ge{sub 10}As{sub 30}Se{sub 60} amorphous thin films

    SciTech Connect (OSTI)

    Hawlová, P.; Olivier, M.; Verger, F. [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); Nazabal, V. [Chemical Sciences Institute of Rennes (ISCR), Glasses and Ceramics Team, UMR-CNRS 6226, University of Rennes 1, 35042 Rennes Cedex (France); Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); N?mec, P., E-mail: petr.nemec@upce.cz [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic)

    2013-10-15T23:59:59.000Z

    Graphical abstract: - Highlights: • Amorphous Ge{sub 20}As{sub 20}Se{sub 60}/Ge{sub 10}As{sub 30}Se{sub 60} films are fabricated by pulsed laser deposition. • Photosensitivity of the layers is studied by employing spectroscopic ellipsometry. • As-deposited/relaxed thin films were irradiated by 593, 635, and 660 nm lasers. • Ge{sub 20}As{sub 20}Se{sub 60} layers present almost zero photorefraction in relaxed state. - Abstract: Amorphous Ge{sub 20}As{sub 20}Se{sub 60} and Ge{sub 10}As{sub 30}Se{sub 60} thin films are fabricated by pulsed laser deposition. Prepared films are characterized in terms of their morphology, chemical composition, and optical properties. Special attention is given to the photosensitivity of the layers, which was studied by spectroscopic ellipsometry with as-deposited, annealed and exposed films by three different laser sources (593, 635, and 660 nm). The results show better photostability for Ge{sub 20}As{sub 20}Se{sub 60} thin films, where photoinduced change of optical band gap was found to be equal or less than 0.04 eV and these layers present almost zero photorefraction.

  10. Optical phonons and the soft mode in 2H-NbSe2

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

    Weber, F.; Hott, R.; Heid, R.; Bohnen, K.-P.; Rosenkranz, S.; Castellan, J.-P.; Osborn, R.; Said, A. H.; Leu, B. M.; Reznik, D.

    2013-06-01T23:59:59.000Z

    We present an investigation of the lattice dynamics of the charge density wave (CDW) compound 2H-NbSe2. We analyze the precise nature of the wave vector-dependent electron-phonon coupling (EPC) and derive the bare dispersion of the CDW soft phonon mode using inelastic x-ray scattering combined with ab initio calculations. Experimentally, phonon modes along the ??M line, i.e., q = (h,0,0), with 0 ? h ? 0.5 and the same longitudinal symmetry (?1) as the CDW soft mode, were investigated up to 32 meV. In agreement with our calculations, we observe significant EPC in the optic modes at h ? 0.2. We analyze the EPC in the optic, as well as acoustic, mode and show that the q dependences stem from scattering processes between two bands at the Fermi surface that both have a Nb 4d character. Finally, we demonstrate that the soft mode dispersion at T = 33 K (=TCDW) can be well described on the basis of a strongly q-dependent EPC matrix element and an acousticlike bare phonon dispersion in agreement with observations near room temperature.

  11. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

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

    Anand, Naween; Gu, Genda; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Martin, C.

    2014-12-01T23:59:59.000Z

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10–300 K) reflectance was measured over 40–7000 cm?¹ (5–870 meV) with an extension to 15,500 cm?¹ (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy opticalmore »spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.« less

  12. Environmental, health and safety issues related to commercializing CuInSe{sub 2}-based photovoltaics

    SciTech Connect (OSTI)

    Eberspacher, C. [UNISUN, Newbury Park, CA (United States); Fthenakis, V.M.; Moskowtiz, P.D. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01T23:59:59.000Z

    Photovoltaics technology is rapidly evolving towards a new generation of low-cost thin film technologies. One of the most promising materials in this new generation is copper indium selenide (CuInSe{sub 2} or CIS). As with any new material, successful commercialization of CIS photovoltaic (PV) technology will require attention to environmental, health and safety issues, including consideration of the sources, usage, and end-of-product-life disposal and/or recycling of the constituent materials. This work focuses on three specific environmental, health and safety (EH and S) issues related to CIS PV: (1) economics are analyzed to determine their impact on materials use and re-use; (2) Federal and California State environmental disposal and waste handling regulations are analyzed to evaluate their impact on PV module manufacturing and end-of-life module handling; and (3) the logistics and economics of product recycling and waste disposal by industries with comparable EH and S issues are examined to quantify the corresponding options available for handling, disposing of and/or recycling manufacturing by-products and end-of-life modules.

  13. Improved Energy Conversion Efficiency in Wide Bandgap Cu(In,Ga)Se2 Solar Cells

    SciTech Connect (OSTI)

    Contreras, M. A.; Mansfield, L. M.; Egaas, B.; Li, J.; Romero, M.; Noufi, R.; Rudiger-Voigt, E.; Mannstadt, W.

    2011-01-01T23:59:59.000Z

    This report outlines improvements to the energy conversion efficiency in wide bandgap (E{sub g} > ;1.2 eV) solar cells based on CuIn{sub 1-x}Ga{sub x}Se{sub 2}. Using (a) alkaline containing high temperature glass substrates, (b) elevated substrate temperatures 600 C-650 C and (c) high vacuum evaporation from elemental sources following NREL's three-stage process, we have been able to improve the performance of wider bandgap solar cells with 1.2 < E{sub g} < 1.45 eV. Initial results of this work have led to efficiencies >18% for absorber bandgaps {approx}1.30 eV and efficiencies {approx}16% for bandgaps up to {approx}1.45 eV. In comparing J-V parameters in similar materials, we establish gains in the open-circuit voltage and, to a lesser degree, the fill factor value, as the reason for the improved performance. The higher voltages seen in these wide gap materials grown at high substrate temperatures may be due to reduced recombination at the grain boundary of such absorber films. Solar cell results, absorber materials characterization, and experimental details are reported.

  14. Processing approach towards the formation of thin-film Cu(In,Ga)Se2

    DOE Patents [OSTI]

    Beck, Markus E. (Falkensee, DE); Noufi, Rommel (Golden, CO)

    2003-01-01T23:59:59.000Z

    A two-stage method of producing thin-films of group IB-IIIA-VIA on a substrate for semiconductor device applications includes a first stage of depositing an amorphous group IB-IIIA-VIA precursor onto an unheated substrate, wherein the precursor contains all of the group IB and group IIIA constituents of the semiconductor thin-film to be produced in the stoichiometric amounts desired for the final product, and a second stage which involves subjecting the precursor to a short thermal treatment at 420.degree. C.-550.degree. C. in a vacuum or under an inert atmosphere to produce a single-phase, group IB-III-VIA film. Preferably the precursor also comprises the group VIA element in the stoichiometric amount desired for the final semiconductor thin-film. The group IB-IIIA-VIA semiconductor films may be, for example, Cu(In,Ga)(Se,S).sub.2 mixed-metal chalcogenides. The resultant supported group IB-IIIA-VIA semiconductor film is suitable for use in photovoltaic applications.

  15. Performance Characterization and Remedy of Experimental CuInGaSe2 Mini-Modules: Preprint

    SciTech Connect (OSTI)

    Pern, F. J.; Yan, F.; Mansfield, L.; Glynn, S.; Rekow, M.; Murion, R.

    2011-07-01T23:59:59.000Z

    We employed current-voltage (I-V), quantum efficiency (QE), photoluminescence (PL), electroluminescence (EL), lock-in thermography (LIT), and (electrochemical) impedance spectroscopy (ECIS) to complementarily characterize the performance and remedy for two pairs of experimental CuInGaSe2 (CIGS) mini-modules. One pair had the three scribe-lines (P1/P2/P3) done by a single pulse-programmable laser, and the other had the P2/P3 lines by mechanical scribe. Localized QE measurements for each cell strip on all four mini-modules showed non-uniform distributions that correlated well with the presence of performance-degrading strips or spots revealed by PL, EL, and LIT imaging. Performance of the all-laser-scribed mini-modules improved significantly by adding a thicker Al-doped ZnO layer and reworking the P3 line. The efficiency on one of the all-laser-scribed mini-modules increased notably from 7.80% to 8.56% after the performance-degrading spots on the side regions along the cell array were isolated by manual scribes.

  16. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    SciTech Connect (OSTI)

    Anand, Naween [Univ. of Florida, Gainesville, FL (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Buvaev, Sanal [Univ. of Florida, Gainesville, FL (United States); Hebard, A. F. [Univ. of Florida, Gainesville, FL (United States); Tanner, D. B. [Univ. of Florida, Gainesville, FL (United States); Chen, Zhiguo [Florida State Univ., Tallahassee, FL (United States); Li, Zhiqiang [Florida State Univ., Tallahassee, FL (United States); Choudhary, Kamal [Univ. of Florida, Gainesville, FL (United States); Sinnott, S. B. [Univ. of Florida, Gainesville, FL (United States); Martin, C. [Ramapo College, Mahwah, NJ (United States)

    2014-12-01T23:59:59.000Z

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10–300 K) reflectance was measured over 40–7000 cm?¹ (5–870 meV) with an extension to 15,500 cm?¹ (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy optical spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.

  17. Disordered stoichiometric nanorods and ordered off-stoichiometric nanoparticles in n-type thermoelectric Bi?Te?.?Se?.?

    E-Print Network [OSTI]

    Carlton, Chris E.

    N-type Bi?Te?.?Se?.? bulk thermoelectric materials with peak ZT values up to ?1 were examined by transmission electron microscopy and electron diffraction. Two nanostructural features were found: (i) a structural modulation ...

  18. Charge Density Waves in Exfoliated Films of van der Waals Materials: Evolution of Raman Spectrum in TiSe2

    E-Print Network [OSTI]

    Charge Density Waves in Exfoliated Films of van der Waals Materials: Evolution of Raman Spectrum graphene-like mechanical exfoliation of TiSe2 crystals to prepare a set of films with different thicknesses

  19. Lattice Thermal conductivity of the Cu3SbSe4-Cu3SbS4 Solid Solution

    SciTech Connect (OSTI)

    Skoug, Eric [Michigan State University, East Lansing; Cain, Jeffrey D. [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing; Kirkham, Melanie J [ORNL; Majsztrik, Paul W [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01T23:59:59.000Z

    The compositional dependence of the crystal structure and lattice thermal conductivity in the Cu3SbSe4-Cu3SbS4 system has been studied. The lattice parameters of the Cu3SbSe4-xSx compounds decrease linearly with x, and the tetragonal structure (space group no. 121) of the end compounds is maintained at all compositions. The thermal conductivity is much lower than that predicted by a simple rule of mixtures, which is typical for a solid solution. The Debye model produces a very reasonable fit to the experimental lattice thermal conductivity data when phonon scattering due to atomic mass and size differences between Se and S is taken into account. Compounds in this series are likely to improve upon the thermoelectric performance of Cu3SbSe4, which has shown ZT=0.72 when optimized.

  20. Epitaxial growth of Cu,,In,Ga...Se2 on GaAs,,110... and A. Rockett

    E-Print Network [OSTI]

    Rockett, Angus

    . INTRODUCTION The Cu(In, Ga)Se2 CIGS absorber layer in a recent record-efficiency CIGS solar cell1 has a 220.13 Commercially supplied ``epi-ready'' liquid- encapsulated Czo

  1. Expanded Prussian Blue Analogues Incorporating [Re6Se8(CN)6]3-/4-Clusters: Adjusting Porosity via Charge Balance

    E-Print Network [OSTI]

    Shores, Matthew P.

    Expanded Prussian Blue Analogues Incorporating [Re6Se8(CN)6]3-/4- Clusters: Adjusting Porosity via of octahedral [M(CN)6]3-/4- complexes for the synthesis of microporous Prussian blue type solids with adjustable to be a direct expansion of Prussian blue (Fe4[Fe(CN)6]3,14H2O), with [Re6Se8(CN)6]4- clusters connected through

  2. Electron drift-mobility measurements in polycrystalline CuIn1-xGaxSe2 solar cells

    E-Print Network [OSTI]

    Schiff, Eric A.

    .1063/1.3692165] The chalcopyrite alloys CuIn1ÀxGaxSe2 (CIGS) are the basis of very promising thin film solar cells, with solar con conduction band states.8,9 Empirical optimization of CIGS for solar cells thus appears to have led to lowElectron drift-mobility measurements in polycrystalline CuIn1-xGaxSe2 solar cells S. A. Dinca, E. A

  3. Device modeling and simulation of the performance of Cu(In1x,Gax)Se2 solar cells

    E-Print Network [OSTI]

    Anderson, Timothy J.

    on the simulation results, an optimal graded band-gap structure for the CIGS solar cell is proposed. The performance-junction Cu(In1Àx,Gax)Se2 (CIGS) solar cells. Increasing the open-circuit voltage (Voc) to improve the overallDevice modeling and simulation of the performance of Cu(In1Àx,Gax)Se2 solar cells Jiyon Song

  4. Artificial Life p1 RJM 08/01/14 SE4SI12 Artificial Life Part A

    E-Print Network [OSTI]

    Mitchell, Richard

    Artificial Life p1 RJM 08/01/14 SE4SI12 Artificial Life ­ Part A © Dr Richard Mitchell 2014 Dr and Applications #12;p2 RJM 08/01/14 SE4SI12 Artificial Life ­ Part A © Dr Richard Mitchell 2014 Aims of Module Aims: Swarm Intelligence and Artificial Life are two active areas of research in computational

  5. Determination of Grain Boundary Charging in Cu(In,Ga)Se2 Thin Films: Preprint

    SciTech Connect (OSTI)

    Jiang, C. S.; Contreras, M. A.; Repins, I.; Moutinho, H. R.; Noufi, R.; Al-Jassim, M. M.

    2012-06-01T23:59:59.000Z

    Surface potential mapping of Cu(In,Ga)Se2 (CIGS) thin films using scanning Kelvin probe force microscopy (SKPFM) aims to understand the minority-carrier recombination at the grain boundaries (GBs) of this polycrystalline material by examining GB charging, which has resulted in a number of publications. However, the reported results are highly inconsistent. In this paper, we report on the potential mapping by measuring wide-bandgap or high-Ga-content films and by using a complementary atomic force microscopy-based electrical technique of scanning capacitance microscopy (SCM). The results demonstrate consistent, positively charged GBs on our high-quality films with minimal surface defects/charges. The potential image taken on a low-quality film with a 1.2-eV bandgap shows significantly degraded potential contrast on the GBs and degraded potential uniformity on grain surfaces, resulting from the surface defects/charges of the low-quality film. In contrast, the potential image on an improved high-quality film with the same wide bandgap shows significantly improved GB potential contrast and surface potential uniformity, indicating that the effect of surface defects is critical when examining GB charging using surface potential data. In addition, we discuss the effect of the SKPFM setup on the validity of potential measurement, to exclude possible artifacts due to improper SKPFM setups. The SKPFM results were corroborated by using SCM measurements on the films with a CdS buffer layer. The SCM image shows clear GB contrast, indicating different electrical impedance on the GB from the grain surface. Further, we found that the GB contrast disappeared when the CdS window layer was deposited after the CIGS film was exposed extensively to ambient, which was caused by the creation of CIGS surface defects by the ambient exposure.

  6. Biological investigations of the Sandia National Laboratories Sol se Mete Aerial Cable Facility

    SciTech Connect (OSTI)

    Sullivan, R.M.

    1994-10-01T23:59:59.000Z

    This report provides results of a comprehensive biological field survey performed on the Sandia National Laboratories Aerial Cable Facility, at the east end of Kirtland Air Force Base (KAFB), Bernalillo County, New Mexico. This survey was conducted late September through October, 1991. ACF occupies a 440-acre tract of land withdrawn by the US Forest Service (USFS) for use by KAFB, and in turn placed under operational control of SNL by the Department of Energy (DOE). All land used by SNL for ACF is part of a 15,851-acre tract of land withdrawn by the US Forest Service. In addition, a number of different organizations use the 15,851-acre area. The project area used by SNL encompasses portions of approximately six sections (3,840 acres) of US Forest Service land located within the foothills of the west side of the Manzano Mountains (East Mesa). The biological study area is used by the KAFB, the US Department of Interior, and SNL. This area includes: (1) Sol se Mete Springs and Canyon, (2) East Anchor Access Road, (3) East Anchor Site, (4) Rocket Sled Track, (5) North Arena, (6) East Instrumentation Site and Access Road, (7) West Anchor Access Road, (8) West Anchor Site, (9) South Arena, (10) Winch Sites, (11) West Instrumentation Sites, (12) Explosive Assembly Building, (13) Control Building, (14) Lurance Canyon Road and vicinity. Although portions of approximately 960 acres of withdrawn US Forest Service land have been altered, only 700 acres have been disturbed by activities associated with ACF; approximately 2,880 acres consist of natural habitat. Absence of grazing by livestock and possibly native ungulates, and relative lack of human disturbance have allowed this area to remain in a more natural vegetative state relative to the condition of private range lands throughout New Mexico. This report evaluates threatened and endangered species found on ACF, as well as a comprehensive assessment of biological habitats.

  7. Selenization of Sb{sub 2}Se{sub 3} absorber layer: An efficient step to improve device performance of CdS/Sb{sub 2}Se{sub 3} solar cells

    SciTech Connect (OSTI)

    Leng, Meiying; Luo, Miao; Chen, Chao; Qin, Sikai; Chen, Jie; Zhong, Jie; Tang, Jiang, E-mail: jtang@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan, 430074 Hubei (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074 Hubei (China)

    2014-08-25T23:59:59.000Z

    Sb{sub 2}Se{sub 3} appeared as a very promising solar absorber because of their attractive material, optical and electrical properties. Previously, we reported thermal evaporated superstrate CdS/Sb{sub 2}Se{sub 3} solar cell achieving 1.9% efficiency. In this letter, we improved device performance to 3.7% (Voc?=?0.335?V, Jsc?=?24.4?mA/cm{sup 2}, and FF?=?46.8%) by an additional selenization step. Careful external quantum efficiency, capacitance-voltage profiling, and photoresponse study indicated selenization probably compensated selenium loss during thermal evaporation, reducing V{sub Se} associated recombination loss and improving device performance.

  8. High field magnetotransport and point contact Andreev reflection measurements on CuCr{sub 2}Se{sub 4} and CuCr{sub 2}Se{sub 3}Br—Degenerate magnetic semiconductor single crystals

    SciTech Connect (OSTI)

    Borisov, K., E-mail: borisovk@tcd.ie; Coey, J. M. D.; Stamenov, P. [School of Physics and CRANN, Trinity College, Dublin 2 (Ireland); Alaria, J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2014-05-07T23:59:59.000Z

    Single crystals of the metallically degenerate fully magnetic semiconductors CuCr{sub 2}Se{sub 4} and CuCr{sub 2}Se{sub 3}Br have been prepared by the Chemical Vapour Transport method, using either Se or Br as transport agents. The high-quality, millimetre-sized, octahedrally faceted, needle- and platelet-shaped crystals are characterised by means of high field magnetotransport (?{sub 0}H? 14?T) and Point Contact Andreev Reflection. The relatively high spin polarisation observed |P|>0.56, together with the relatively low minority carrier effective mass of 0.25 m{sub e}, and long scattering time  10{sup ?13}?s, could poise these materials for integration in low- and close-to-room temperature minority injection bipolar heterojunction transistor demonstrations.

  9. Thermodynamic model for the solubility of BaSeO4(cr) in the aqueous Ba2+-SeO42--Na+-H+-OH--H2O system: Extending to high selenate concentrations

    SciTech Connect (OSTI)

    Rai, Dhanpat; Felmy, Andrew R.; Moore, Dean A.; Kitamura, Akira; Yoshikawa, Hideki; Doi, Reisuke; Yoshida, Yasushi

    2014-09-15T23:59:59.000Z

    The solubility of Ba(SeO4, SO4) precipitates was determined as a function of the BaSeO4 mole fractions, ranging from 0.0015 to 0.3830, and time with an equilibration period extending to as long as 302 days. Equilibrium/steady state conditions in this system are reached in ? 65 days. Pitzer’s ion interaction model was used to calculate solid and aqueous phase activity coefficients. Thermodynamic analyses showed that the data do not satisfy Gibbs-Duhem equation, thereby demonstrating that a single-solid solution phase does not control both the selenate and sulfate concentrations. Our extensive data with log10 [Ba]) ranging from -3.6 to -5.9 mol.kg-1, log10 [SeO4]) ranging from -3.6 to -5.2 mol.kg-1, and log10 [SO4] ranging from -4.0 to -5.3 mol.kg-1 can be explained with the formation of an ideal BaSeO4 solid solution phase that controls the selenium concentrations and a slightly disordered/less-crystalline BaSO4(s) (log10 K0sp = -9.5 instead of -10.05 for barite) that controls the sulfate concentrations. In these experiments the BaSO4 component of the solid solution phase never reaches thermodynamic equilibrium with the aqueous phase. Thermodynamic interpretations of the data show that both the ideal BaSeO4 solid solution phase and less-crystalline BaSO4(s) phase are in equilibrium with each other in the entire range of BaSeO4 mole fractions investigated in this study.

  10. Synthesis of Bi{sub 2}Se{sub 3} thermoelectric nanosheets and nanotubes through hydrothermal co-reduction method

    SciTech Connect (OSTI)

    Cui Hongmei [State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan City, Shandong Province 250100 (China); Liu Hong [State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan City, Shandong Province 250100 (China)]. E-mail: hongliu@sdu.edu.cn; Li Xia [State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan City, Shandong Province 250100 (China); Wang Jiyang [State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan City, Shandong Province 250100 (China)]. E-mail: jywang@icm.sdu.edu.cn; Han Feng [State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan City, Shandong Province 250100 (China); Zhang Xudong [State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan City, Shandong Province 250100 (China); Boughton, R.I. [Department of Physics and Astronomy, Bowling Green State University, Bowling Green, OH 43403 (United States)

    2004-11-01T23:59:59.000Z

    Bi{sub 2}Se{sub 3} nanosheets and nanotubes were prepared by a hydrothermal co-reduction method at 150, 180, 200, and 210{sup o}C. Bi{sub 2}Se{sub 3} nanosheets, nanobelts and nanotubes were obtained. The Bi{sub 2}Se{sub 3} nanoflakes are 50-500nm in width and 2-5nm in thickness. The Bi{sub 2}Se{sub 3} nanotubes are 5-10nm in diameter, 80-120nm in length, and 1.3nm in wall thickness. X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and electron diffraction were employed to characterize the products. Experimental results showed that the nanosheets and the nanotubes are hexagonal in structure with a=4.1354A and c=27.4615A. A possible formation and crystal growth mechanism of Bi{sub 2}Se{sub 3} nanostructures is proposed.

  11. Syntheses, crystal structures, and properties of three new metal selenites Na{sub 2}Co{sub 2}(SeO{sub 3}){sub 3}, Na{sub 2}Co{sub 1.67}Ni{sub 0.33}(SeO{sub 3}){sub 3}, and Na{sub 2}Ni{sub 2}(SeO{sub 3}){sub 3}

    SciTech Connect (OSTI)

    Yuan Xiaoqing [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Feng Meiling, E-mail: fml@fjirsm.ac.c [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, the Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Li Jianrong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, the Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Huang Xiaoying, E-mail: xyhuang@fjirsm.ac.c [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2010-09-15T23:59:59.000Z

    Three new sodium cobalt (nickel) selenite compounds, namely, Na{sub 2}Co{sub 2}(SeO{sub 3}){sub 3}, Na{sub 2}Co{sub 1.67}Ni{sub 0.33}(SeO{sub 3}){sub 3}, and Na{sub 2}Ni{sub 2}(SeO{sub 3}){sub 3} have been hydro-/solvothermally synthesized in the mixed solvents of acetonitrile and water. Single-crystal X-ray diffraction analyses reveal that these isostructural compounds belong to the orthorhombic Cmcm space group and their structures feature three-dimensional open frameworks constructed by the two-dimensional layers of [MSeO{sub 3}] pillared by the [SeO{sub 3}]{sup 2-} groups. The two different types of Na{sup +} ions reside in the intersecting two-dimensional channels parallel to the a- and c-axes, respectively. Their thermal properties have been investigated via TGA-DSC. The magnetic measurements indicate the existence of the antiferromagnetic interactions in these compounds. - Graphical abstract: Three new isostructural metal selenites, Na{sub 2}Co{sub 2}(SeO{sub 3}){sub 3}, Na{sub 2}Co{sub 1.67}Ni{sub 0.33}(SeO{sub 3}){sub 3}, and Na{sub 2}Ni{sub 2}(SeO{sub 3}){sub 3} have been hydro-/solvothermally synthesized and characterized. Their structures feature three-dimensional open frameworks with Na{sup +}-occupied channels.

  12. Quasiparticle interference, quasiparticle interactions, and the origin of the charge density wave in 2H-NbSe?

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

    Arguello, C. J.; Valla, T.; Rosenthal, E. P.; Andrade, E. F.; Jin, W.; Yeh, P. C.; Zaki, N.; Jia, S.; Cava, R. J.; Fernandes, R. M.; et al

    2015-01-01T23:59:59.000Z

    We show that a small number of intentionally introduced defects can be used as a spectroscopic tool to amplify quasiparticle interference in 2H-NbSe?, that we measure by scanning tunneling spectroscopic imaging. We show from the momentum and energy dependence of the quasiparticle interference that Fermi surface nesting is inconsequential to charge density wave formation in 2H-NbSe?. We demonstrate that by combining quasiparticle interference data with additional knowledge of the quasiparticle band structure from angle resolved photoemission measurements, one can extract the wavevector and energy dependence of the important electronic scattering processes thereby obtaining direct information both about the fermiology andmore »the interactions. In 2H-NbSe?, we use this combination to show that the important near-Fermi-surface electronic physics is dominated by the coupling of the quasiparticles to soft mode phonons at a wave vector different from the CDW ordering wave vector.« less

  13. Quasiparticle interference, quasiparticle interactions, and the origin of the charge density wave in 2H-NbSe?

    SciTech Connect (OSTI)

    Arguello, C. J. [Columbia Univ., New York, NY (United States); Valla, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rosenthal, E. P. [Columbia Univ., New York, NY (United States); Andrade, E. F. [Columbia Univ., New York, NY (United States); Jin, W. [Columbia Univ., New York, NY (United States); Yeh, P. C. [Columbia Univ., New York, NY (United States); Zaki, N. [Columbia Univ., New York, NY (United States); Jia, S. [Princeton Univ., NJ (United States); Cava, R. J. [Princeton Univ., NJ (United States); Fernandes, R. M. [Univ., of Minnesota, Minneapolis, MN (United States); Millis, A. J. [Columbia Univ., New York, NY (United States); Osgood, Jr., R. M. [Columbia Univ., New York, NY (United States); Princeton Univ., Princeton, NJ (United States); Pasupathy, A. N. [Columbia Univ., New York, NY (United States)

    2015-01-01T23:59:59.000Z

    We show that a small number of intentionally introduced defects can be used as a spectroscopic tool to amplify quasiparticle interference in 2H-NbSe?, that we measure by scanning tunneling spectroscopic imaging. We show from the momentum and energy dependence of the quasiparticle interference that Fermi surface nesting is inconsequential to charge density wave formation in 2H-NbSe?. We demonstrate that by combining quasiparticle interference data with additional knowledge of the quasiparticle band structure from angle resolved photoemission measurements, one can extract the wavevector and energy dependence of the important electronic scattering processes thereby obtaining direct information both about the fermiology and the interactions. In 2H-NbSe?, we use this combination to show that the important near-Fermi-surface electronic physics is dominated by the coupling of the quasiparticles to soft mode phonons at a wave vector different from the CDW ordering wave vector.

  14. Quasiparticle interference, quasiparticle interactions, and the origin of the charge density wave in 2H-NbSe?

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

    Arguello, C. J. [Columbia Univ., New York, NY (United States); Valla, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rosenthal, E. P. [Columbia Univ., New York, NY (United States); Andrade, E. F. [Columbia Univ., New York, NY (United States); Jin, W. [Columbia Univ., New York, NY (United States); Yeh, P. C. [Columbia Univ., New York, NY (United States); Zaki, N. [Columbia Univ., New York, NY (United States); Jia, S. [Princeton Univ., NJ (United States); Cava, R. J. [Princeton Univ., NJ (United States); Fernandes, R. M. [Univ., of Minnesota, Minneapolis, MN (United States); Millis, A. J. [Columbia Univ., New York, NY (United States); Osgood, Jr., R. M. [Columbia Univ., New York, NY (United States); Princeton Univ., Princeton, NJ (United States); Pasupathy, A. N. [Columbia Univ., New York, NY (United States)

    2015-01-01T23:59:59.000Z

    We show that a small number of intentionally introduced defects can be used as a spectroscopic tool to amplify quasiparticle interference in 2H-NbSe?, that we measure by scanning tunneling spectroscopic imaging. We show from the momentum and energy dependence of the quasiparticle interference that Fermi surface nesting is inconsequential to charge density wave formation in 2H-NbSe?. We demonstrate that by combining quasiparticle interference data with additional knowledge of the quasiparticle band structure from angle resolved photoemission measurements, one can extract the wavevector and energy dependence of the important electronic scattering processes thereby obtaining direct information both about the fermiology and the interactions. In 2H-NbSe?, we use this combination to show that the important near-Fermi-surface electronic physics is dominated by the coupling of the quasiparticles to soft mode phonons at a wave vector different from the CDW ordering wave vector.

  15. Syntheses, structures, and properties of Ag{sub 4}(Mo{sub 2}O{sub 5})(SeO{sub 4}){sub 2}(SeO{sub 3}) and Ag{sub 2}(MoO{sub 3}){sub 3}SeO{sub 3}

    SciTech Connect (OSTI)

    Ling Jie [Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, AL 36849 (United States); Albrecht-Schmitt, Thomas E. [Department of Chemistry and Biochemistry, 179 Chemistry Building, Auburn University, Auburn, AL 36849 (United States)], E-mail: albreth@auburn.edu

    2007-05-15T23:59:59.000Z

    Ag{sub 4}(Mo{sub 2}O{sub 5})(SeO{sub 4}){sub 2}(SeO{sub 3}) has been synthesized by reacting AgNO{sub 3}, MoO{sub 3}, and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO{sub 2} {sup 2+} molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C {sub 2} distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C {sub 2} distortion. Upon heating Ag{sub 4}(Mo{sub 2}O{sub 5})(SeO{sub 4}){sub 2}(SeO{sub 3}) looses SeO{sub 2} in two distinct steps to yield Ag{sub 2}MoO{sub 4}. Crystallographic data: (193 K; MoK{alpha}, {lambda}=0.71073 A): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) A, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2{sigma}(I). Ag{sub 2}(MoO{sub 3}){sub 3}SeO{sub 3} was synthesized by reacting AgNO{sub 3} with MoO{sub 3}, SeO{sub 2}, and HF under hydrothermal conditions. The structure of Ag{sub 2}(MoO{sub 3}){sub 3}SeO{sub 3} consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO{sub 6} units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoK{alpha}, {lambda}=0.71073 A): monoclinic, space group P2{sub 1} /n, a=7.7034(5), b=11.1485(8), c=12.7500(9) A, {beta}=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2{sigma}(I). Ag{sub 2}(MoO{sub 3}){sub 3}SeO{sub 3} decomposes to Ag{sub 2}Mo{sub 3}O{sub 10} on heating above 550 deg. C. - Graphical abstract: A view of the one-dimensional [(Mo{sub 2}O{sub 5})(SeO{sub 4}){sub 2}(SeO{sub 3})]{sup 4-} chains that extend down the c-axis in the structure of Ag{sub 4}(Mo{sub 2}O{sub 5})(SeO{sub 4}){sub 2}(SeO{sub 3})

  16. Observation of an electron band above the Fermi level in FeTe?.??Se?.?? from in-situ surface doping

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

    Zhang, P. [Chinese Academy of Sciences (CAS), Beijing (China); Gu, G. D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Richard, P. [Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Xu, N. [Chinese Academy of Sciences (CAS), Beijing (China); Paul Scherrer Inst. (PSI), Villigen (Switzerland); Xu, Y. -M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ma, J. [Chinese Academy of Sciences (CAS), Beijing (China); Qian, T. [Chinese Academy of Sciences (CAS), Beijing (China); Fedorov, A. V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Denlinger, J. D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ding, H. [Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-10-27T23:59:59.000Z

    We used in-situ potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe?.??Se?.??. The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily-electron-doped KFe??xSe? compound.

  17. Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3

    SciTech Connect (OSTI)

    Sobota, Jonathan

    2012-03-14T23:59:59.000Z

    Using femtosecond time- and angle-resolved photoemission spectroscopy, we investigated the nonequilibrium dynamics of the topological insulator Bi{sub 2}Se{sub 3}. We studied p-type Bi{sub 2}Se{sub 3}, in which the metallic Dirac surface state and bulk conduction bands are unoccupied. Optical excitation leads to a meta-stable population at the bulk conduction band edge, which feeds a nonequilibrium population of the surface state persisting for >10 ps. This unusually long-lived population of a metallic Dirac surface state with spin texture may present a channel in which to drive transient spin-polarized currents.

  18. Enhancement of surface phonon modes in the Raman spectrum of ZnSe nanoparticles on adsorption of 4-mercaptopyridine

    SciTech Connect (OSTI)

    Islam, Syed K.; Lombardi, John R. [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)] [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)

    2014-02-21T23:59:59.000Z

    By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm{sup ?1}) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations.

  19. Critical current density and mechanism of vortex pinning in KxFe2-ySe? doped with S

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

    Lei, Hechang; Petrovic, C.

    2011-08-01T23:59:59.000Z

    We report the critical current density Jc in KxFe2-ySe2-zSz crystals. The Jc can be enhanced significantly with optimal S doping (z=0.99). For K0.70(7)Fe1.55(7)Se1.01(2)S0.99(2), the weak fishtail effect is found for H II c. The normalized vortex pinning forces follow the scaling law with a maximum position at 0.41 of the reduced magnetic field. These results demonstrate that the small size normal point defects dominate the vortex pinning mechanism.

  20. From 1D Chain to 3D Network: Syntheses, Structures, and Properties of K2MnSn2Se6, K2MnSnSe4, and

    E-Print Network [OSTI]

    Li, Jing

    and MnSe4 tetrahedra, with large channels hosting the K+ cations. III is a layered compound containing 2 tetrahedra into two-dimensional (2D) sheets.1 The 1D 1 [SnQ3]2- rib- bons have also been observed- rahedra to Ag atoms, with large channels hosting the K+ cations.4 In this paper, we report the preparation

  1. Synthesis and Phase Transformation of In2Se3 and CuInSe2 Nanowires Hailin Peng, David T. Schoen, Stefan Meister, Xiao Feng Zhang, and Yi Cui*,

    E-Print Network [OSTI]

    Cui, Yi

    pathways without deadends, which is an advantage over the random p-n junctions. Therefore, NW solar cells10 films of CuInxGa1-xSe2 (CIGS) have been demon- strated to have a high-power efficiency of 19.2%,4 which

  2. Ternary chalcogenide-based photoelectrochemical cells V. Surface analyses of the CuInX/sub 2//aqueous polysulfide interface (X = S, Se) by X-Ray photoelectron spectroscopy; absence of Se/S exchange in the CuInSe/sub 2//S /SUB n/ = system

    SciTech Connect (OSTI)

    Mirovsky, Y.; Cahen, D.; Polak, M.; Sawatzky, G.; Tenner, R.

    1985-05-01T23:59:59.000Z

    n-CuInS/sub 2/ and n-CuInSe/sub 2/ were subjected to surface analyses by x-ray photoelectron and Auger electron spectroscopy, after their use as photoanodes in polysulfide solutions. For CuInS/sub 2/ samples that had a poor (ca. 2%) conversion efficiency, a rather heterogeneous surface was found, with patches rich in In, which is probably present mainly as oxide. Some CuO was found as well, although the top layer was depleted in Cu, compared to a reference sample. More efficient (ca. 5%) samples showed a more homogeneous surface and even stronger Cu depletion. These changes are ascribed to additional surface treatments, viz., dipping in hot KCN solution and thermal oxidation o the resultant etched surface. For CuInSe/sub 2/ samples, no significant exchange of lattice Se by S from the polysulfide solution is seen, in sharp contrast to what is observed for CdSe or CdIn/sub 2/Se/sub 4/. If sulfur is found, its presence could be correlated with the spurious occurrence of Cd (used as dopant) or Ag (used for the ohmic back contact). Cu depletion also occur near the surface of the diselenide after use in polysulfide solution. Most of the remaining In seems to occur in indiu oxide and/or indium selenide. Cu/sub 2/ was found neither here nor on the surface of the more efficient disulfide sample. It is suggested that the occurrence of an indium oxide top layer, aided by thermal oxidation of the electrode in the case o CuInSe/sub 2/, has a beneficial effect on electrode performance.

  3. Structural and dynamical properties of Bridgman-grown CdSe[subscript x]Te[subscript 1?x] (0alloys

    E-Print Network [OSTI]

    Talwar, Devki N.

    Measurements of the Raman scattering and extended x-ray-absorption fine-structure (EXAFS) spectroscopy are reported on a series of Bridgman-grown zinc-blende CdTe[subscript 1?x]Se[subscript x] (0.35 ? x > 0.05) ternary ...

  4. Transition threshold in Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang, E-mail: lfang@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Shen, Xiang [Laboratory of Infrared Material and Devices, Advanced Technology Research Institute, Ningbo University, Ningbo 315211 (China); Wang, Rong-Ping [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2014-03-21T23:59:59.000Z

    Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses with Ge content from 7.5 to 32.5?at.?% have been prepared by melt-quench technique, and the physical parameters including glass transition temperature (T{sub g}), density (?), compactness (C), shear elastic moduli (C{sub s}), compression elastic moduli (C{sub c}), refractive index (n), and optical bandgap (E{sub g}) have been investigated. While all these physical parameters show threshold behavior in the glass with a chemically stoichiometric composition. Raman spectra analysis also indicates that, with increasing Ge content, Se-chains or rings gradually disappear until all Se-atoms are consumed in the glass with a chemically stoichiometric composition. With further increasing Ge content, homopolar Ge-Ge and Sb-Sb bonds are formed and the chemical order in the glasses is violated. The threshold behavior of the physical properties in the Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses can be traced to demixing of networks above the chemically stoichiometric composition.

  5. Investigations on the StranskiKrastanow growth of CdSe quantum dots D. Schikora,a)

    E-Print Network [OSTI]

    Nabben, Reinhard

    , respectively. Recording clear resolved RHEED oscillations in combination with phase-locked epi- taxy, the Cd type B islands are correlated with a phase transition via a Stranski­Krastanow growth process of about 15 mW as excitation source. The CdSe QD samples grown in this study show typical structural

  6. Vegetation and climate dynamics during the early Middle Miocene from Lake Sinj (Dinaride Lake System, SE Croatia)

    E-Print Network [OSTI]

    Jiménez-Moreno, Gonzalo

    System, SE Croatia) Gonzalo Jiménez-Moreno a, , Oleg Mandic b , Mathias Harzhauser b , Davor Paveli c of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia A B S T R A C TA R T I C L E I N F O Article history 2008 Keywords: pollen vegetation climate change Miocene Croatia Pollen data from sediments from

  7. Green synthesis of highly efficient CdSe quantum dots for quantum-dots-sensitized solar cells

    SciTech Connect (OSTI)

    Gao, Bing; Shen, Chao; Zhang, Mengya; Yuan, Shuanglong; Yang, Yunxia, E-mail: yangyunxia@ecust.edu.cn, E-mail: grchen@ecust.edu.cn; Chen, Guorong, E-mail: yangyunxia@ecust.edu.cn, E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Bo [Department of Physics, East China University of Science and Technology, Shanghai 200237 (China)

    2014-05-21T23:59:59.000Z

    Green synthesis of CdSe quantum dots for application in the quantum-dots-sensitized solar cells (QDSCs) is investigated in this work. The CdSe QDs were prepared with glycerol as the solvent, with sharp emission peak, full width at half maximum around 30?nm, and absorption peak from 475?nm to 510?nm. The reaction is environmental friendly and energy saving. What's more, the green synthesized CdSe QDs are coherence to the maximum remittance region of the solar spectrum and suitable as sensitizers to assemble onto TiO{sub 2} electrodes for cell devices application. What's more, the dynamic procedure of the carriers' excitation, transportation, and recombination in the QDSCs are discussed. Because the recombination of the electrons from the conduction band of TiO{sub 2}'s to the electrolyte affects the efficiency of the solar cells greatly, 3-Mercaptopropionic acid capped water-dispersible QDs were used to cover the surface of TiO{sub 2}. The resulting green synthesized CdSe QDSCs with Cu{sub 2}S as the electrode show a photovoltaic performance with a conversion efficiency of 3.39%.

  8. Wind profile above the surface boundary layer S.-E. Gryning (1), E. Batchvarova (2) and B. Brmmer (3)

    E-Print Network [OSTI]

    Wind profile above the surface boundary layer S.-E. Gryning (1), E. Batchvarova (2) and B. Brümmer in predictions of the wind profile in the lowest hundreds me- ters of the atmosphere, being connected to the general increase in height of structures such as bridges, high houses and wind turbines. The hub height

  9. Emplacement in an extensional setting of the Mont LozreBorne granitic complex (SE France) inferred from

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Emplacement in an extensional setting of the Mont Lozère­Borne granitic complex (SE France of the Late Hercynian Mont Lozère­Borne granitic complex (French Massif Central), which consists of several carried out to characterize the internal fabrics of the granitic plutons. Throughout the Pont

  10. Journal of Crystal Growth 310 (2008) 29872994 Reaction kinetics of CuGaSe2 formation from

    E-Print Network [OSTI]

    Anderson, Timothy J.

    2008-01-01T23:59:59.000Z

    of polycrystalline thin-film Cu(InxGa1Àx)Se2 (CIGS) solar cells achieved over the past several decades appears. Copper gallium diselenide; B3. Solar cells 1. Introduction The continuous improvement in the efficiency for the top cell in a CIGS tandem structure [2­4], given its suitable band gap energy (1.68 eV), process

  11. Band-gap grading in Cu(In,Ga)Se2 solar cells M. Gloeckler and J. R. Sites

    E-Print Network [OSTI]

    Sites, James R.

    Band-gap grading in Cu(In,Ga)Se2 solar cells M. Gloeckler and J. R. Sites Department of Physics solar cells, and some researchers have asserted that these fields can enhance performance to show that (1) there can be a beneficial effect of grading, (2) in standard thick- ness CIGS cells

  12. Effect of Ga content on defect states in CuIn1xGaxSe2 photovoltaic devices

    E-Print Network [OSTI]

    Rockett, Angus

    gaps for single junction solar cells expected to be around 1.4 eV.2 This corresponds to a Ga fraction x gap of CuIn1 xGaxSe2 CIGS . This technique is sensitive to opti- cal absorption in the active layer CIGS. Photovoltaic devices based on thin polycrystalline CIGS absorbers have achieved record lab

  13. Toward microscale Cu,,In,Ga...Se2 solar cells for efficient conversion and optimized material usage: Theoretical evaluation

    E-Print Network [OSTI]

    Boyer, Edmond

    develop a model to predict the performances of microscale Cu In,Ga Se2 CIGS solar cells under concentrated limiting factor for concentration on CIGS solar cells. This model can be used to extract the value associated with the operation of microscale CIGS solar cells are studied. The optimum concentration ratio

  14. The effect of Na in polycrystalline and epitaxial single-crystal CuIn1xGaxSe2

    E-Print Network [OSTI]

    Rockett, Angus

    online 15 December 2004 Abstract Na is found to improve the performance of Cu(In,Ga)Se2 (CIGS) solar the highest efficiency, exceeding 19%, of any thin film polycrystalline solar cell [1]. The diodes work well cells although the mechanism is not clear. This paper briefly reviews some of the observations on Na

  15. Investigation of defect properties in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy

    E-Print Network [OSTI]

    Anderson, Timothy J.

    mechanisms (and hence the minority-carrier lifetimes) in CIGS solar cells. Zhang [1] has calculatedInvestigation of defect properties in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy cells. Three solar cells developed using different absorber growth technologies were analyzed using DLTS

  16. Shear wave splitting in SE Brazil: an eect of active or fossil upper mantle ow, or both?

    E-Print Network [OSTI]

    Barruol, Guilhem

    Shear wave splitting in SE Brazil: an e¡ect of active or fossil upper mantle £ow, or both?§ Maggy, Brazil c Universidade de SaBrazil Received 26 the structure of the upper mantle beneath southeastern Brazil using teleseismic shear wave splitting

  17. Hole transport and doping states in epitaxial CuIn1 xGaxSe2 David J. Schroeder

    E-Print Network [OSTI]

    Rockett, Angus

    interest in renewable energy sources such as photovoltaic devices. CuIn1 xGaxSe2 CIGS /CdS hetero- junction there is no evidence of any degradation of performance in these devices.1­5 In light of the current belief in the Cu

  18. Photoemission Spectroscopy of Magnetic and Nonmagnetic Impurities on the Surface of the Bi2Se3 Topological Insulator

    E-Print Network [OSTI]

    Ohta, Shigemi

    Topological Insulator T. Valla,1,* Z.-H. Pan,1 D. Gardner,2 Y. S. Lee,2 and S. Chu3 1 Condensed Matter Physics; published 12 March 2012) Dirac-like surface states on surfaces of topological insulators have a chiral spin impurities on the surface of Bi2Se3, a model topological insulator. We reveal a remarkable insensitivity

  19. PHYSICAL REVIEW B 83, 165440 (2011) Electron interaction-driven insulating ground state in Bi2Se3 topological insulators

    E-Print Network [OSTI]

    Wang, Wei Hua

    2011-01-01T23:59:59.000Z

    topological insulators in the two-dimensional limit Minhao Liu,1 Cui-Zu Chang,1,2 Zuocheng Zhang,1 Yi Zhang,2 of ultrathin Bi2Se3 topological insulators with thickness from one quintuple layer to six quintuple layers that this unusual insulating ground state in the two-dimensional limit of topological insulators is induced

  20. Resumen--En este trabajo se describe la aplicacin de tcnicas de descubrimiento de reglas de descripcin de

    E-Print Network [OSTI]

    Granada, Universidad de

    Resumen-- En este trabajo se describe la aplicación de técnicas de descubrimiento de reglas de enseñanza a distancia Moodle. El objetivo consiste en extraer reglas que describan relaciones entre el uso a distancia, algoritmos evolutivos, reglas difusas. I. INTRODUCCI�N En la actualidad existe un incremento de

  1. Ctedra de Salud Laboral La Ctedra de Salud Laboral para la prevencin de riesgos derivados del trabajo se cre

    E-Print Network [OSTI]

    Oro, Daniel

    trabajo se creó en 2009 para continuar las actividades de la Cátedra Fundación MAPFRE en relación con la salud laboral (seguridad en el trabajo, higiene industrial, ergonomía y psicosociología aplicada) en los modalidades de enseñanza: semipresencial en el campus de la UIB y a distancia, sobre la plataforma telemática

  2. O final de ano se aproxima e as tempesta-des severas e as "chuvas contnuas" voltam

    E-Print Network [OSTI]

    Domingues, Margarete Oliveira

    , enquanto se investiu na melhoria de infra-estrutura de energia do prédio do CPTEC. Como fruto deste esforço IDD- análise de grande variedade de dados Brasil, que tem no CPTEC o seu centro mais meteorológicos

  3. Biologically programmed synthesis of core-shell CdSe/ZnS nanocrystalsw Shailendra Singh,ab

    E-Print Network [OSTI]

    Chen, Wilfred

    not only directs the nucleation of inorganic materials, but also controls the crystal structure and sizeBiologically programmed synthesis of core-shell CdSe/ZnS nanocrystalsw Shailendra Singh report of core-shell semiconductor nanocrystal synthesis using a peptide template. Type II

  4. Temperature dependent Raman scattering studies of three dimensional topological insulators Bi{sub 2}Se{sub 3}

    SciTech Connect (OSTI)

    Irfan, Bushra; Chatterjee, Ratnamala, E-mail: rmala@physics.iitd.ac.in [Department of Physics, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India); Sahoo, Satyaprakash; Gaur, Anand P. S.; Ahmadi, Majid; Katiyar, Ram S. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931 (United States); Guinel, Maxime J.-F. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931 (United States); Department of Chemistry, College of Natural Sciences, University of Puerto Rico, P.O. Box 70377, San Juan, Puerto Rico 00936-8377 (United States)

    2014-05-07T23:59:59.000Z

    We investigate the temperature dependent (83?K?T?523?K) frequency shift of 2A{sub g}{sup 1} and 1E{sub g}{sup 2} phonon modes in the three dimensional topological insulator Bi{sub 2}Se{sub 3}, using Raman spectroscopy. The high quality single crystals of Bi{sub 2}Se{sub 3} were grown using a modified Bridgman technique and characterized by Laue diffraction and high resolution transmission electron microscopy. A significant broadening in the line shape and red-shift in the frequencies were observed with increase in temperature. Polarized Raman scattering measurement shows a strong polarization effect of A{sub g}{sup 1} and A{sub g}{sup 2} phonon modes which confirms the good quality single crystals of Bi{sub 2}Se{sub 3}. Temperature co-efficient for A{sub 1g}{sup 1},?E{sub g}{sup 2}, and A{sub 1g}{sup 2} modes was estimated to be ?1.44?×?10{sup ?2}, ?1.94?×?10{sup ?2}, and ?1.95?×?10{sup ?2}?cm{sup ?1}?K, respectively. Our results shed light on anharmonic properties of Bi{sub 2}Se{sub 3}.

  5. Latest Ordovicianearliest Silurian acritarchs and chitinozoans from1 subsurface samples in Jebel Asba, Kufra Basin, SE Libya2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Asba, Kufra Basin, SE Libya2 3 Bindra Thusu1 , Syed Rasul1 , Florentin Paris2 , Guido Meinhold3 & Gas B.V., Dat Al Imad Complex Tower 5 Floor 13, P.O. Box 91651, Tripoli,15 Libya16 17 * Corresponding of the Kufra Basin,36 southeastern Libya, yielded well-diversified palynomorph assemblages with transparent and

  6. DETERMINATION OF BACK CONTACT BARRIER HEIGHT IN Cu(In,Ga)(Se,S)2 AND CdTe SOLAR CELLS

    E-Print Network [OSTI]

    Sites, James R.

    DETERMINATION OF BACK CONTACT BARRIER HEIGHT IN Cu(In,Ga)(Se,S)2 AND CdTe SOLAR CELLS Galymzhan T-contact metallization. The input data is the current- voltage (J-V) curves for the solar cell measured over a range point technique and apply it to specific solar-cell examples. The range of Jt that can be practically

  7. Peer-reviewed Publications in 2008 1. Bellinger BJ, Underwood GJC, Ziegler SE and Gretz MR (2008) The

    E-Print Network [OSTI]

    Peer-reviewed Publications in 2008 1. Bellinger BJ, Underwood GJC, Ziegler SE and Gretz MR (2008-inflammatory activities of a new class of 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes. Bioorganic & Medicinal, Korea; Sept.28-Oct. 1, 2008; pg. 46-51. 5. Busov VB, Brunner AM and Strauss SH (2008) Genes for control

  8. in: D. E. Dobbs, M. Fontana, S.-E. Kabbaj (eds.), Advances in Commutative Ring Theory (Fes III Conf. 1997)

    E-Print Network [OSTI]

    Frisch, Sophie

    , which shows r to be invertible.) This prompts the question how many functions on R are representablein: D. E. Dobbs, M. Fontana, S.-E. Kabbaj (eds.), Advances in Commutative Ring Theory (Fes III Conf. 1997) Lecture Notes in Pure and Appl. Mathematics 205, Dekker 1999, pp 323­336. POLYNOMIAL FUNCTIONS

  9. in: D. E. Dobbs, M. Fontana, S.-E. Kabbaj (eds.), Advances in Commutative Ring Theory (Fes III Conf. 1997)

    E-Print Network [OSTI]

    Frisch, Sophie

    + . .+.anrn-1 )r, which shows r to be invertible.) This prompts the question how many functions on R in: D. E. Dobbs, M. Fontana, S.-E. Kabbaj (eds.), Advances in Commutative Ring Theory (Fes III-336. POLYNOMIAL FUNCTIONS ON FI NITE COMMUTATIVE RI NGS

  10. Ab initio molecular-dynamics study of the structural, vibrational, and electronic properties of glassy GeSe 2

    E-Print Network [OSTI]

    Drabold, David

    Ab initio molecular-dynamics study of the structural, vibrational, and electronic properties We present results of an ab initio molecular-dynamics study of glassy GeSe2 using a 216 atom model static structure factors, and ring structures. The total static structure factor and first sharp

  11. OPTIMIZATION STUDY OF COPPER PRECURSORS FOR HIGH QUALITY CuInSe2 NANOPARTICLES BY WET CHEMICAL ROUTE

    E-Print Network [OSTI]

    Anderson, Timothy J.

    of the most promising material system for thin film photovoltaics owing to their unique structural, respectively. The synthesis process was optimized to grow 20 to 150 nm sized nanostructures of CuInSe2 inherent merits in reducing the cost per watt of the fabricated PV modules. Various size, shape

  12. Presentacin del ISO El Instituto de Sntesis Orgnica (ISO), se constituye como un Instituto Universitario de Investigacin en

    E-Print Network [OSTI]

    Escolano, Francisco

    Presentación del ISO El Instituto de Síntesis Orgánica (ISO), se constituye como un Instituto. El ISO está implicado también en actividades docentes referidas a enseñanzas en un Programa de de sus competencias. El ISO fomentará la relación con otras entidades públicas y privadas

  13. Process Creation in JavaProcess Creation in Java Note: Java really doesn't implement processes per se, but

    E-Print Network [OSTI]

    Klassner, Frank

    Process Creation in JavaProcess Creation in Java · Note: Java really doesn't implement processes per se, but provides a clean interface to spawn processes to run system programs outside of the JVM · "Process" class in Java ­ Runtime.getRuntime.exec("") method will return a process object (interface

  14. BIOTECHNOL. & BIOTECHNOL. EQ. 24/2010/SE SECOND BALKAN CONFERENCE ON BIOLOGY SPECIAL EDITION/ON-LINE 21-23 MAY 2010, PLOVDIV

    E-Print Network [OSTI]

    Mollov, Ivelin Aldinov

    263 BIOTECHNOL. & BIOTECHNOL. EQ. 24/2010/SE SECOND BALKAN CONFERENCE ON BIOLOGY SPECIAL EDITION #12;264 BIOTECHNOL. & BIOTECHNOL. EQ. 24/2010/SE SECOND BALKAN CONFERENCE ON BIOLOGY SPECIAL EDITION

  15. High-pressure single-crystal X-ray diffraction of Tl{sub 2}SeO{sub 4}

    SciTech Connect (OSTI)

    Grzechnik, Andrzej [Departamento de Fisica de la Materia Condensada, Universidad del Pais Vasco, E-48080 Bilbao (Spain)], E-mail: andrzej.grzechnik@ehu.es; Breczewski, Tomasz; Friese, Karen [Departamento de Fisica de la Materia Condensada, Universidad del Pais Vasco, E-48080 Bilbao (Spain)

    2008-11-15T23:59:59.000Z

    The effect of pressure on the crystal structure of thallium selenate (Tl{sub 2}SeO{sub 4}) (Pmcn, Z=4), containing the Tl{sup +} cations with electron lone pairs, has been studied with single-crystal X-ray diffraction in a diamond anvil cell up to 3.64 GPa at room temperature. No phase transition has been observed. The compressibility data are fitted by a Murnaghan equation of state with the zero-pressure bulk modulus B{sub 0}=29(1) GPa and the unit-cell volume at ambient pressure V{sub 0}=529.6(8) A{sup 3} (B'=4.00). Tl{sub 2}SeO{sub 4} is the least compressible in the c direction, while the pressure-induced changes of the a and b lattice parameters are quite similar. These observations can be explained by different pressure effects on the nine- and 11-fold coordination polyhedra around the two non-equivalent Tl atoms. The SeO{sub 4}{sup 2-} tetrahedra are not rigid units and become more distorted. Their contribution to the compressibility is small. The effect of pressure on the isotypical oxide materials A{sub 2}TO{sub 4} with the {beta}-K{sub 2}SO{sub 4} structure is discussed. It appears that the presence of electron lone pairs on the Tl{sup +} cation does not seem to influence the compressibility of Tl{sub 2}SeO{sub 4}. - Graphical abstract: Pressure dependence of normalized lattice parameters and unit-cell volumes in Tl{sub 2}SeO{sub 4} (Pmcn, Z=4). The solid line is the Murnaghan equation of state.

  16. 6 mW and 30 mW laser threshold for respectively 1st Brillouin Stokes order in a Ge10As24Se68 chalcogenide fiber.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    fiber made of chalcogenide glass to make a BFL [5]. A 3 meter long suspended-core AsSe chalcogenide have replaced the suspended-core chalcogenide AsSe previously used by a microstructured Ge10As24Se68 diameter of the AsSe suspended- core fiber is 240 µm and the core diameter d is 3.8 µm. The mode effective

  17. H-bond network dynamics of the solid-state protonic conductor Rb3H(SeO4)2 from FTIR and IINS measurements

    E-Print Network [OSTI]

    Schuck, Götz

    that the identified modes (m1[SeO4]2À , m1[HSeO4]1À , m3[SeO4]2À and m3[HSeO4]1À ) can be classified in two groups: alternation between the association of the monomers [HSeO4]1À and [SeO4]2À resulting in the dimer [H(SeO4)2]3À

  18. Chemical order in Ge{sub x}As{sub y}Se{sub 1-x-y} glasses probed by high resolution X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Xu, S. W. [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); College of Applied Sciences, Beijing University of Technology, Beijing100124 (China); Wang, R. P.; Luther-Davies, B. [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Kovalskiy, A. [Department of Physics and Astronomy, Austin Peay State University, Clarksville, Tennessee 37043 (United States); Miller, A. C.; Jain, H. [Department of Materials Science and Engineering, Lehigh University, 5 East Packer Avenue, Bethlehem, Pennsylvania 18015-3195 (United States)

    2014-02-28T23:59:59.000Z

    We have measured high-resolution x-ray photoelectron spectra of Ge{sub x}As{sub y}Se{sub 1-x-y} glasses with a mean coordination number (MCN) from 2.2 to 2.78. The valence band spectra showed that a number of Se–Se–Se trimers can be found in Se-rich samples, whilst multiband features induced by phase separation can be observed in extremely Se-poor samples. When the Ge, As, and Se 3d spectra were decomposed into several doublets, which correspond, respectively, to different chemical environments, the perfect AsSe{sub 3/2} pyramidal and GeSe{sub 4/2} tetrahedral structures in Se-rich samples gradually evolved into defect structures, including As–As and Ge–Ge homopolar bonds, with increasing Ge and As concentrations. Two transition-like features were found at MCN?=?2.5 and 2.64–2.72 that correspond first to the disappearance of Se-chains in the glass network and, subsequently, destruction of the perfect GeSe{sub 4/2} tetrahedral structures, respectively.

  19. Three-dimensional topological insulators Bi{sub 2}Te{sub 3}, Bi{sub 2}Se{sub 3}, and Bi{sub 2}Te{sub 2}Se - a microwave spectroscopy study

    SciTech Connect (OSTI)

    Wolos, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland and Faculty of Physics, University of Warsaw, ul Hoza 69, 00-681 Warsaw (Poland); Drabinska, A.; Szyszko, S.; Kaminska, M. [Faculty of Physics, University of Warsaw, ul Hoza 69, 00-681 Warsaw (Poland); Strzelecka, S. G.; Hruban, A.; Materna, A.; Piersa, M. [Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland)

    2013-12-04T23:59:59.000Z

    We present results of investigations of three-dimensional topological insulators from a family of bismuth compounds performed in electron spin resonance spectrometer. Next to the standard spin resonance spectra in Bi{sub 2}Se{sub 3} originating from bulk conduction electrons (g{sub Verbar;} = 27.5 ± 0.1 and g{sub ?} = 19.5 ± 0.1), we observed also cyclotron resonance due to topological surface states in Bi{sub 2}Te{sub 3} and non-resonant signal related to weak anti-localization in Bi{sub 2}Te{sub 2}Se. The analysis of the cyclotron resonance signal yields low Fermi velocity equal to 3250 m/s in Bi{sub 2}Te{sub 3}. The phase coherence length determined from weak anti-localization signal equals to 550 nm at low temperatures in Bi{sub 2}Te{sub 2}Se. Relation of the signals to bulk, topological surface or two-dimensional quantum well states is discussed and where possible indicated.

  20. Application of Single Wall Carbon Nanotubes as Transparent Electrodes in Cu(In,Ga)Se2-Based Solar Cells: Preprint

    SciTech Connect (OSTI)

    Contreras, M.; Barnes, T.; van de Lagemaat, J.; Rumbles, G.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.

    2006-05-01T23:59:59.000Z

    We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell results from devices made using CuIn1-xGaxSe2 thin-film absorber materials. Achieving an energy conversion efficiency of >12% and a quantum efficiency of {approx}80% demonstrate the feasibility of the concept. A discussion of the device structures will be presented considering the physical properties of the new electrodes comparing current-voltage results from the new solar cell structure and those from standard ZnO/CdS/Cu(In,Ga)Se2/Mo solar cells.

  1. Large positive magnetoresistance effects in the dilute magnetic semiconductor (Zn,Mn)Se in the regime of electron hopping

    SciTech Connect (OSTI)

    Jansson, F., E-mail: fjansson@abo.fi; Wiemer, M.; Gebhard, F.; Baranovskii, S. D. [Department of Physics and Material Sciences Center, Philipps-University, D-35032 Marburg (Germany); Nenashev, A. V. [Institute of Semiconductor Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Petznick, S.; Klar, P. J. [Institute of Experimental Physics I, Justus-Liebig-University Giessen, D-35392 Giessen (Germany); Hetterich, M. [Institut für Angewandte Physik and Center for Functional Nanostructures (CFN), Universität Karlsruhe, D-76131 Karlsruhe (Germany)

    2014-08-28T23:59:59.000Z

    Magnetoresistance in dilute magnetic semiconductors is studied in the hopping transport regime. Measurements performed on Cl-doped Zn{sub 1–x}Mn{sub x}Se with x?Se with donor concentrations below the metal–insulator transition.

  2. Synthesis, Crystal Structure, and Magnetism of ?-Fe1.00(2)Se1.00(3) Single Crystals

    SciTech Connect (OSTI)

    Petrovic, C.; Billinge, S.

    2011-06-20T23:59:59.000Z

    Understanding iron-based superconductors requires high-quality impurity-free single crystals. So far they have been elusive for {beta}-FeSe and extraction of intrinsic materials properties has been compromised by several magnetic-impurity phases. Here, we report synchrotron-clean {beta}-FeSe superconducting single crystals grown via LiCl/CsCl flux method. Phase purity yields evidence for a defect-induced weak ferromagnetism that coexists with superconductivity below T{sub c}. In contrast to Fe{sub 1+y}Te-based superconductors, our results reveal that the interstitial Fe(2) site is not occupied and that all contribution to density of states at the Fermi level must come from in-plane Fe(1).

  3. Comment prsenter une demande afin d'obtenir un nouveau visa de rsident temporaire ? (demandeurs se trouvant au Canada)

    E-Print Network [OSTI]

    Parrott, Lael

    se trouvant au Canada) Si vous vous trouvez actuellement au Canada en vertu d'un statut valide de présenter votre demande depuis le Canada si vous répondez aux critères suivants : Vous êtes un résident temporaire (étudiant ou travailleur étranger temporaire seulement) admis légalement au Canada et vous

  4. Depositional environments, diagenesis, and porosity development of Mississippian Chappel carbonates at Thrash and Quanah SE Fields, Hardeman County, Texas

    E-Print Network [OSTI]

    He, Shiliang T.

    1989-01-01T23:59:59.000Z

    ) . This shale, rich in organic matter, thins to the west and is considered to be the potential source rock for the Mississippian reservoirs (Montgomery, 1984) . Later active tectonics resulted in input of clastics to the edges of the basin from basement... Formation at Thrash and Quanah SE Fields is characterized by deep-water limestones with local skeletal buildups on a low-energy, distally-steepened ramp. Three depositional environments have been recognized from these lv rocks: 1) the deep ? water...

  5. OXYDATION COMPARE DU NIOBIUM ET D'UN ALLIAGE (P 353 M) A BA SE DE NIOBIUM

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    519 OXYDATION COMPARÉE DU NIOBIUM ET D'UN ALLIAGE (P 353 M) A BA SE DE NIOBIUM E. FRIES, C. MARHIC'oxydation comparée du Niobium pur et d'un alliage à base de Niobium de composition suivante : W V Ti Zr C 10 % 1 100 h. Dans les deux cas (niobium et alliage) on a mis en évidence la présence de trois formes de l

  6. A Basis Set of Re6Se8 Cluster Building Blocks and Demonstration of Their Linking Capability: Directed Synthesis

    E-Print Network [OSTI]

    of 4 with AgBF4 in dichloromethane/acetonitrile gave cis-[Re6Se8(PEt3)4(MeCN)2]2+ (7); a similar at 180 °C for 24 h under dynamic vacuum, the compounds [8]X2 (X ) BF4 -, SbF6 -) lose acetonitrile, which can give only one logical product upon deligation of acetonitrile. The synthesis concept

  7. friction se boratoire : Lab

    E-Print Network [OSTI]

    Paris-Sud 11, Université de

    , dans lequ apport à la sur gout prononcé DEA) qui vou e : OUI NON Plots micrométriq ncepts Fondam sique

  8. Midea: Order (2010-SE-0110, 2012-SE-1402, 2012-SE-1404, 2013-SE-1401) |

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed offOCHCO2:Introduction toManagement of the National 93-4 AcquisitionO 231.1B

  9. PHaSe-EFRC

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy, science,SpeedingWu,IntelligenceYou are hereNewsOur site willRise

  10. Temperature and composition phase diagram in the iron-based ladder compounds Ba 1 - x Cs x Fe 2 Se 3

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

    Hawai, Takafumi; Nambu, Yusuke; Ohgushi, Kenya; Du, Fei; Hirata, Yasuyuki; Avdeev, Maxim; Uwatoko, Yoshiya; Sekine, Yurina; Fukazawa, Hiroshi; Ma, Jie; Chi, Songxue; Ueda, Yutaka; Yoshizawa, Hideki; Sato, Taku J.

    2015-05-01T23:59:59.000Z

    We investigated the iron-based ladder compounds (Ba,Cs)Fe?Se?. Their parent compounds BaFe?Se? and CsFe?Se? have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe?Se? is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe?Se? is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe?Se?, but interladder spin configuration is different. Intermediate compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures.

  11. Thermoelectric properties of M{sub 2}Mo{sub 6}Se{sub 6} (M =Tl,In)

    SciTech Connect (OSTI)

    Verebelyi, D.T.; Payne, J.E.; Tessema, G.X.; Mengistu, E.

    1997-07-01T23:59:59.000Z

    The authors have measured the thermal conductivity of Tl{sub 2}Mo{sub 6}Se{sub 6}, a quasi-one dimensional conductor which belongs to the family of M{sub 2}Mo{sub 6}X{sub 6} linear chain compounds. Using these results and the measurements of the Seebeck coefficient and the electrical conductivity the authors estimate the dimensionless figure of merit to be of the order of 0.08. This result suggest that this compound and other related compounds are good potential TE.

  12. Properties of electrospun CdS and CdSe filled poly(methyl methacrylate) (PMMA) nanofibres

    SciTech Connect (OSTI)

    Mthethwa, T.P. [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa)] [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa); Moloto, M.J., E-mail: mmoloto@uj.ac.za [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa); De Vries, A.; Matabola, K.P. [CSIR Materials Science and Manufacturing, 4 Gomery avenue, Summerstrand, Port Elizabeth 6000 (South Africa)] [CSIR Materials Science and Manufacturing, 4 Gomery avenue, Summerstrand, Port Elizabeth 6000 (South Africa)

    2011-04-15T23:59:59.000Z

    Graphical abstract: SEM images of CdS/PMMA showing coiling as loading of CdS nanoparticles is increased. Thermal stability is increased with increase in %loading of both CdS and CdSe nanoparticles. Research highlights: {yields} TOPO-capped CdS and HDA-capped CdSe nanoparticles were synthesized and fully characterized. {yields} The nanoparticles were mixed with the polymer, PMMA using electrospinning technique using 2, 5 and 10% weight loadings. {yields} The mixture was spun to produce fibres with optical and thermal properties showing significant change and also the increase in loading causing bending or spiraling. {yields} Both TEM images for nanoparticles and SEM for fibres shows the morphology and sizes of the particles. -- Abstract: Electrospinning technique was used to fabricate poly(methyl methacrylate) (PMMA) fibres incorporating CdS and CdSe quantum dots (nanoparticles). Different nanoparticle loadings (2, 5 and 10 wt% with respect to PMMA) were used and the effect of the quantum dots on the properties of the fibres was studied. The optical properties of the hybrid composite fibres were investigated by photoluminescence and UV-vis spectrophotometry. Scanning electron microscopy (SEM), X-ray diffraction and FTIR spectrophotometry were also used to investigate the morphology and structure of the fibres. The optical studies showed that the size-tunable optical properties can be achieved in the polymer fibres by addition of quantum dots. SEM images showed that the morphologies of the fibres were dependent on the added amounts of quantum dots. A spiral type of morphology was observed with an increase in the concentration of CdS and CdSe nanoparticles. Less beaded structures and bigger diameter fibres were obtained at higher quantum dot concentrations. X-ray diffractometry detected the amorphous peaks of the polymer and even after the quantum dots were added and the FTIR analysis shows that there was no considerable interaction between the quantum dots and the polymer fibres at low concentration of quantum dots however at higher concentrations some interactions were observed which shows that QDs were present on the surfaces of the fibres.

  13. Synthesis and crystal structure of layered chalcogenides [KCuFeS[sub 2] and KCuFeSe[sub 2

    SciTech Connect (OSTI)

    Mujica, C.; Paez, J.; Llanos, J. (Univ. Catolica del Norte, Antofagasta (Chile). Dept. de Quimica)

    1994-03-01T23:59:59.000Z

    The new layer chalcogenides KCuFeS[sub 2] and KCuFeSe[sub 2] have been prepared from the copper iron chalcogenide and potassium carbonate. Both phases crystallize with tetragonal symmetry, in the space group I4/mmm (Nr 139) with a=383.7 (1) pm, c=1338.4 (4) pm and a=397.9 (2) pm, c = 1378.7 (54) pm respectively in the ThCr[sub 2]Si[sub 2]-type structure. The chalcogen atoms form bidimensional layers of edge sharing pyramids. Copper and iron are statistically distributed in tetrahedral sites. The potassium ions are placed in cubic sites between the layers.

  14. Conductance modulation in topological insulator Bi{sub 2}Se{sub 3} thin films with ionic liquid gating

    SciTech Connect (OSTI)

    Son, Jaesung; Banerjee, Karan; Yang, Hyunsoo, E-mail: eleyang@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)] [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Brahlek, Matthew; Koirala, Nikesh; Oh, Seongshik [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854 (United States)] [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854 (United States); Lee, Seoung-Ki [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of) [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Ahn, Jong-Hyun [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)] [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2013-11-18T23:59:59.000Z

    A Bi{sub 2}Se{sub 3} topological insulator field effect transistor is investigated by using ionic liquid as an electric double layer gating material, leading to a conductance modulation of 365% at room temperature. We discuss the role of charged impurities on the transport properties. The conductance modulation with gate bias is due to a change in the carrier concentration, whereas the temperature dependent conductance change is originated from a change in mobility. Large conductance modulation at room temperature along with the transparent optical properties makes topological insulators as an interesting (opto)electronic material.

  15. Electrically driven single photon emission from a CdSe/ZnSSe single quantum dot at 200?K

    SciTech Connect (OSTI)

    Quitsch, Wolf; Kümmell, Tilmar; Bacher, Gerd [Werkstoffe der Elektrotechnik and CENIDE, Universität Duisburg-Essen, Bismarckstraße 81, 47057 Duisburg (Germany); Gust, Arne; Kruse, Carsten; Hommel, Detlef [Institut für Festkörperphysik, Universität Bremen, Otto-Hahn-Allee 1, 28334 Bremen (Germany)

    2014-09-01T23:59:59.000Z

    High temperature operation of an electrically driven single photon emitter based on a single epitaxial quantum dot is reported. CdSe/ZnSSe/MgS quantum dots are embedded into a p-i-n diode architecture providing almost background free excitonic and biexcitonic electroluminescence from individual quantum dots through apertures in the top contacts. Clear antibunching with g{sup 2}(??=?0)?=?0.28?±?0.20 can be tracked up to T?=?200?K, representing the highest temperature for electrically triggered single photon emission from a single quantum dot device.

  16. Strain-Dependent Photoluminescence Behavior of CdSe/CdS Nanocrystals with Spherical, Linear, and Branched Topologies

    SciTech Connect (OSTI)

    Choi, Charina L.; Koski, Kristie J.; Sivasankar, Sanjeevi; Alivisatos, A. Paul

    2009-08-13T23:59:59.000Z

    The photoluminescence of CdSe/CdS core/shell quantum dots, nanorods, and tetrapods is investigated as a function of applied hydrostatic and non-hydrostatic pressure. The optoelectronic properties of all three nanocrystal morphologies are affected by strain. Furthermore, it is demonstrated that the unique morphology of a tetrapod is highly sensitive to non-isotropic stress environments. Seeded tetrapods can thereby serve as an optical strain gauge, capable of measuring forces on the order of nanonewtons. We anticipate that a nanocrystal strain gauge with optical readout will be useful for applications ranging from sensitive optomechanical devices to investigations of biomechanical processes.

  17. Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell interfaces and implications for improving performance

    E-Print Network [OSTI]

    Goddard III, William A.

    Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell (2014) Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell of CIGS (Cu(In,Ga)Se2) based solar cells (20.8% efficiency) makes them promising candidate photovoltaic

  18. 87Rb and 85Rb NQR study of phase transitions in RbH3(SeO3)2 J. Seliger, V. 017Dagar, R. Blinc

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    521 87Rb and 85Rb NQR study of phase transitions in RbH3(SeO3)2 J. Seliger, V. 017Dagar, R. Blinc J résonance quadrupolaire de 85Rb et 87Rb dans le composé RbH3(SeO3)2 par une technique de double résonance SeO3. Nous avons confirmé l'existence d'une phase incommensurable intermédiaire entre Tc et Tc + 4 K

  19. TOPOLOGIA 1 e Topologia per Fisica 22/6/2009 1. Esercizio. Se X `e spazio topologico e Y `e un insieme, una funzione f : X Y

    E-Print Network [OSTI]

    Marconi, Umberto

    TOPOLOGIA 1 e Topologia per Fisica ­ 22/6/2009 1. Esercizio. Se X `e spazio topologico e Y `e un insieme, una funzione f : X Y `e detta localmente costante se per ogni p X esiste un intorno U di p in X tale che la restrizione f|U `e costante. Dimostrare che se X `e connesso, allora ogni f : X Y che sia

  20. Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    1 Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells, Setagaya-ku, Tokyo 157-8572, Japan (Received ) KEYWORDS: ZnS buffer, Cu(In,Ga)Se2, thin-film solar cells alternative to CdS in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency

  1. DEVELOPMENT OF A NOVEL PRECURSOR FOR THE PREPARATION BY SELENIZATION OF HIGH EFFICIENCY CuInGaSe2/CdS THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Romeo, Alessandro

    /CdS THIN FILM SOLAR CELLS N. Romeo1 , A. Bosio1 , V. Canevari2 , R. Tedeschi1 , S. Sivelli1 , A. Solar cells prepared by depositing in sequence on top of the CuInGaSe2 film 60 nm of CdS, 100 nm of pure(InGa)Se2, Thin Films, Selenization 1 INTRODUCTION CuInGaSe2 based solar cells exhibit the highest

  2. Quand la paix se construit sur l'oubli des dmobiliss : anciens gurilleros et anciens soldats dans la socit salvadorienne de l'aprs-guerre

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Quand la paix se construit sur l'oubli des démobilisés : anciens guérilleros et anciens soldats

  3. Influence of grain boundary modification on limited performance of wide bandgap Cu(In,Ga)Se{sub 2} solar cells

    SciTech Connect (OSTI)

    Raghuwanshi, M., E-mail: mohit.raghuwanshi@etu.univ-rouen.fr; Cadel, E.; Pareige, P.; Duguay, S. [Groupe de Physique des Materiaux (GPM), UMR 6634 CNRS, Université et INSA de Rouen, Avenue de l'Universite BP 12, 76801 Saint Etienne du Rouvray (France); Couzinie-Devy, F.; Arzel, L.; Barreau, N. [Institut des Materiaux Jean Rouxel (IMN), UMR 6502 CNRS, Université de Nantes, 2 rue de la Houssiniere BP 32229, 44322 Nantes cedex 3 (France)

    2014-07-07T23:59:59.000Z

    The reason why so-called wide-bandgap CuIn{sub 1?x}Ga{sub x}Se{sub 2} (CIGSe with x?>?0.4) based solar cells show hindered performance compared with theoretical expectations is still a matter of debate. In the present Letter, atom probe tomography studies of CuIn{sub 1?x}Ga{sub x}Se{sub 2} polycrystalline thin films with x varying from 0 to 1 are reported. These investigations confirm that the grain boundaries (GBs) of low gallium containing (x??0.8) are Cu-enriched compared with GI. For intermediate gallium contents (0.4?

  4. Visible Light Photoreduction of CO{sub 2} Using CdSe/Pt/TiO{sub 2} Heterostructured Catalysts

    SciTech Connect (OSTI)

    Wang, Congjun [Parsons Project Services, South Park, PA (United States); Thompson, Robert L. [Parsons Project Services, South Park, PA (United States); Baltrus, John [National Energy Technology Laboratory (NETL), Pittsburgh, PA, (United States); Matranga, Christopher [National Energy Technology Laboratory (NETL), Pittsburgh, PA, (United States)

    2010-08-01T23:59:59.000Z

    A series of CdSe quantum dot (QD)-sensitized TiO{sub 2} heterostructures have been synthesized, characterized, and tested for the photocatalytic reduction of CO{sub 2} in the presence of H{sub 2}O. Our results show that these heterostructured materials are capable of catalyzing the photoreduction of CO{sub 2} using visible light illumination (? > 420 nm) only. The effect of removing surfactant caps from the CdSe QDs by annealing and using a hydrazine chemical treatment have also been investigated. The photocatalytic reduction process is followed using infrared spectroscopy to probe the gas-phase reactants and gas chromatography to detect the products. Gas chromatographic analysis shows that the primary reaction product is CH{sub 4}, with CH{sub 3}OH, H{sub 2}, and CO observed as secondary products. Typical yields of the gas-phase products after visible light illumination (?>420 nm) were 48 ppm g{sup -1} h{sup -1} of CH{sub 4}, 3.3 ppm g{sup -1} h{sup -1} of CH{sub 3}OH (vapor), and trace amounts of CO and H{sub 2}.

  5. Proc. of the 24th IEEE Photovoltaic Specialists Conference (IEEE, New York, 1995), pp. 291-294. ADMITTANCE MEASUREMENTS ON Cu(In,Ga)Se2 POLYCRYSTALLINE THIN-

    E-Print Network [OSTI]

    Scofield, John H.

    for approximately 30 CIS and CIGS polycrystalline thin film solar cells having efficiencies of 12% or better-294. ADMITTANCE MEASUREMENTS ON Cu(In,Ga)Se2 POLYCRYSTALLINE THIN- FILM SOLAR CELLS John H. Scofield Physics-16.4% efficient, 0.43 cm2 area, polycrystalline, thin-film solar cells solar cells from 16 different CuInSe2 (CIS

  6. Z .Thin Solid Films 372 2000 212 217 Z .Na in selenized Cu In,Ga Se on Na-containing and Na-free2

    E-Print Network [OSTI]

    Rockett, Angus

    of the substrate glass on standard Z . Z .production Cu In Ga Se CIGS -based solar cells fabricated by selenization; Selenides2 1. Introduction Z .Production of large quantities of Cu In Ga Se1yx x 2 Z . Z .CIGS -based solar solar cell performance. Impurities, both U Corresponding author. Tel.: q1-217-333-0417; fax: q1

  7. [P6Se12]4-: A Phosphorus-Rich Selenophosphate with Low-Valent P In Chung, Angela L. Karst, David P. Weliky, and Mercouri G. Kanatzidis*

    E-Print Network [OSTI]

    Weliky, David

    [P6Se12]4-: A Phosphorus-Rich Selenophosphate with Low-Valent P Centers In Chung, Angela L. Karst, David P. Weliky, and Mercouri G. Kanatzidis* Department of Chemistry, Michigan State UniVersity, East Lansing, Michigan 48824 Received January 19, 2006 The new selenophosphate Rb4P6Se12 features the trans

  8. Micro-Raman spectroscopy of mechanically exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2Te3 materials

    E-Print Network [OSTI]

    Micro-Raman spectroscopy of mechanically exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2-like" exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2Te3. It is found that crystal symmetry breaking

  9. Mxico es central para cualquier esfuerzo de conservacin dirigido a las aves migratorias nerticas, osea las que se reproducen al norte de Mxico e inviernan

    E-Print Network [OSTI]

    Montana, University of

    , osea las que se reproducen al norte de México e inviernan al sur de sus áreas reproductivas. Más rapaces, aves nocturnas, ven- cejos y golondrinas) que se reproducen al norte de la frontera con México e. HUTTO 3 reproducen, respectivamente, al oeste y al este de las Montañas Rocallosas y al norte de la

  10. Interface Driven Energy Filtering of Thermoelectric Power in Spark Plasma Sintered Bi2Te2.7Se0.3 Nanoplatelet Composites

    E-Print Network [OSTI]

    Xiong, Qihua

    Interface Driven Energy Filtering of Thermoelectric Power in Spark Plasma Sintered Bi2Te2.7Se0 of the thermodynamic environment during spark plasma sintering (SPS) on the TE performance of bulk figure of merit, Bi2Te2.7Se0.3 nanoplatelet composites, spark plasma sintering, interfaces, grain

  11. Population Pulsation Resonances of Excitons in Monolayer MoSe 2 with Sub- 1 ? eV Linewidths

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

    Schaibley, John?R.; Karin, Todd; Yu, Hongyi; Ross, Jason?S.; Rivera, Pasqual; Jones, Aaron?M.; Scott, Marie?E.; Yan, Jiaqiang; Mandrus, D.?G.; Yao, Wang; Fu, Kai-Mei; Xu, Xiaodong

    2015-04-01T23:59:59.000Z

    Monolayer transition metal dichalcogenides, a new class of atomically thin semiconductors, possess optically coupled 2D valley excitons. The nature of exciton relaxation in these systems is currently poorly understood. Here, we investigate exciton relaxation in monolayer MoSe? using polarization-resolved coherent nonlinear optical spectroscopy with high spectral resolution. We report strikingly narrow population pulsation resonances with two different characteristic linewidths of 1 and <0.2 ?eV at low temperature. These linewidths are more than 3 orders of magnitude narrower than the photoluminescence and absorption linewidth, and indicate that a component of the exciton relaxation dynamics occurs on time scales longer than 1 ns. The ultranarrow resonance (<0.2 ?eV) emerges with increasing excitation intensity, and implies the existence of a long-lived state whose lifetime exceeds 6 ns.

  12. Insulating and metallic spin glass in Ni-doped K x Fe 2 - y Se 2 single crystals

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

    Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng; Lei, Hechang; Lazarevic, N.; Warren, J. B.; Bozin, E. S.; Popovic, Z. V.; Petrovic, C.

    2015-05-01T23:59:59.000Z

    We report electron doping effects by Ni in KxFe2-?-yNiySe?(0.06?y?1.44) single-crystal alloys. A rich ground-state phase diagram is observed. A small amount of Ni (~4%) suppressed superconductivity below 1.8 K, inducing insulating spin-glass magnetic ground state for higher Ni content. With further Ni substitution, metallic resistivity is restored. For high Ni concentration in the lattice the unit cell symmetry is high symmetry I4/mmm with no phase separation whereas both I4/m+I4/mmm space groups were detected in the phase separated crystals when concentration of Ni < Fe. The absence of superconductivity coincides with the absence of crystalline Fe vacancy order.

  13. Insulating and metallic spin glass in Ni-doped KxFe2-ySe? single crystals

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

    Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng; Lei, Hechang; Lazarevic, N.; Warren, J. B.; Bozin, E. S.; Popovic, Z. V.; Petrovic, C.

    2015-05-01T23:59:59.000Z

    We report electron doping effects by Ni in KxFe2???yNiySe? (0.06 ? y ? 1.44) single crystal alloys. A rich ground state phase diagram is observed. A small amount of Ni (~ 4%) suppressed superconductivity below 1.8 K, inducing insulating spin glass magnetic ground state for higher Ni content. With further Ni substitution, metallic resistivity is restored. For high Ni concentration in the lattice the unit cell symmetry is high symmetry I4/mmm with no phase separation whereas both I4/m + I4/mmm space groups were detected in the phase separated crystals when concentration of Ni more »with the absence of crystalline Fe vacancy order.« less

  14. Nuclear structure relevant to neutrinoless double {beta} decay: The valence protons in {sup 76}Ge and {sup 76}Se

    SciTech Connect (OSTI)

    Kay, B. P.; Schiffer, J. P.; Rehm, K. E. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Freeman, S. J. [University of Manchester, Manchester M13 9PL (United Kingdom); Adachi, T.; Fujita, H.; Hatanaka, K.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Suda, K.; Tameshige, Y.; Tamii, A. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Clark, J. A.; Deibel, C. M.; Wrede, C. [Yale University, New Haven, Connecticut 06520 (United States); Fujita, Y. [Department of Physics, Osaka University, Toyonaka, Osaka 567-0043 (Japan); Grabmayr, P. [Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen (Germany); Meada, Y. [Department of Applied Physics, Miyazaki University, Miyazaki 889-2192 (Japan); Sakemi, Y. [Cyclotron Radioisotope Center, Tohoku University, Sendai, Miyagi 980-8578 (Japan)] (and others)

    2009-02-15T23:59:59.000Z

    The possibility of observing neutrinoless double {beta} decay offers the opportunity of determining the effective neutrino mass if the nuclear matrix element were known. Theoretical calculations are uncertain, and the occupation of valence orbits by nucleons active in the decay is likely to be important. The occupation of valence proton orbits in the ground states of {sup 76}Ge, a candidate for such decay, and {sup 76}Se, the corresponding daughter nucleus, is determined by precisely measuring cross sections for proton-removing transfer reactions. As in previous work on neutron occupation, we find that the Fermi surface for protons is much more diffuse than previously thought, and the occupancies of at least three orbits change significantly between the two 0{sup +} ground states.

  15. Nuclear structure relevant to neutrinoless double {beta} decay : the valence protons in {sup 76}Ge and {sup 76}Se.

    SciTech Connect (OSTI)

    Kay, B. P.; Schiffer, J. P.; Freeman, S. J.; Adachi, T.; Clark, J. A.; Deibel, C. M.; Fujita, H.; Fujita, Y.; Grabmayr, P.; Hatanaka, K.; Ishikawa, D.; Matsubara, H.; Meada, Y.; Okamura, H.; Rehm, K. E.; Sakemi, T.; Shimizu, Y.; Shimoda, H.; Suda, K.; Tameshige, Y.; Tamii, A.; Wrede, C.; Univ. of Manchester; Osaka Univ.; Yale Univ.; Univ. of Tuebingen; Miyazaki Univ.; Tohoku Univ.; Univ. of Tokyo; Kyushu Univ.

    2009-01-01T23:59:59.000Z

    The possibility of observing neutrinoless double {beta} decay offers the opportunity of determining the effective neutrino mass if the nuclear matrix element were known. Theoretical calculations are uncertain, and the occupation of valence orbits by nucleons active in the decay is likely to be important. The occupation of valence proton orbits in the ground states of {sup 76}Ge, a candidate for such decay, and {sup 76}Se, the corresponding daughter nucleus, is determined by precisely measuring cross sections for proton-removing transfer reactions. As in previous work on neutron occupation, we find that the Fermi surface for protons is much more diffuse than previously thought, and the occupancies of at least three orbits change significantly between the two 0{sup +} ground states.

  16. Nuclear Structure Relevant to Neutrinoless Double Beta Decay: the Valence Protons in 76Ge and 76Se

    E-Print Network [OSTI]

    B. P. Kay; J. P. Schiffer; S. J. Freeman; T. Adachi; J. A. Clark; C. M. Deibel; H. Fujita; Y. Fujita; P. Grabmayr; K. Hatanaka; D. Ishikawa; H. Matsubara; Y. Meada; H. Okamura; K. E. Rehm; Y. Sakemi; Y. Shimizu; H. Shimoda; K. Suda; Y. Tameshige; A. Tamii; C. Wrede

    2008-10-22T23:59:59.000Z

    The possibility of observing neutrinoless double beta decay offers the opportunity of determining the effective neutrino mass if the nuclear matrix element were known. Theoretical calculations are uncertain and the occupations of valence orbits by nucleons active in the decay are likely to be important. The occupation of valence proton orbits in the ground states of 76Ge, a candidate for such decay, and 76Se, the corresponding daughter nucleus, were determined by precisely measuring cross sections for proton-removing transfer reactions. As in previous work on neutron occupations, we find that the Fermi surface for protons is much more diffuse than previously thought, and the occupancies of at least three orbits change significantly between the two 0+ ground states.

  17. Ultrafast transmission electron microscopy on dynamic process of a CDW transition in 1T-TaSe2

    E-Print Network [OSTI]

    Sun, Shuaishuai; Li, Zhongwen; Cao, Gaolong; Liu, Y; Lu, W J; Sun, Y P; Tian, Huanfang; HuaixinYang,; Li, Jianqi

    2015-01-01T23:59:59.000Z

    Four-dimensional ultrafast transmission electron microscopy (4D-UTEM) measurements reveal a rich variety of structural dynamic phenomena at a phase transition in the charge-density-wave (CDW) 1T-TaSe2. Through the photoexcitation, remarkable changes on both the CDW intensity and orientation are clearly observed associated with the transformation from a commensurate (C) into an incommensurate (IC) phase in a time-scale of about 3 ps. Moreover, the transient states show up a notable "structurally isosbestic point" at a wave vector of qiso where the C and IC phases yield their diffracting efficiencies in an equally ratio. This fact demonstrates that the crystal planes parallel to qiso adopts visibly common structural features in these two CDW phases. The second-order characters observed in this nonequilibrium phase transition have been also analyzed based on the time-resolved structural data.

  18. Structural investigation on Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses using x-ray photoelectron spectra

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Xiang, Shen [College of Information Science and Engineering, Ningbo University, Ningbo 315211 (China); Xu, Si-Wei; Wang, Rong-Ping, E-mail: rongping.wang@anu.edu.au [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang [Department of Applied Physics, Chongqing University, Chongqing 401331 (China)

    2014-05-14T23:59:59.000Z

    The structure of Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses (x?=?7.5, 10, 15, 20, 25, 27.5, 30, and 32.5 at. %) has been investigated by x-ray photoelectron spectroscopy (XPS). Different structural units have been extracted and characterized by decomposing XPS core level spectra, the evolution of the relative concentration of each structural unit indicates that, the relative contributions of Se-trimers and Se-Se-Ge(Sb) structure decrease with increasing Ge content until they become zero at chemically stoichiometric glasses of Ge{sub 25}Sb{sub 10}Se{sub 65}, and then the homopolar bonds like Ge-Ge and Sb-Sb begin to appear in the spectra. Increase of homopolar bonds will extend band-tails into the gap and narrow the optical band gap. Thus, the glass with a stoichiometric composition generally has fewer defective bonds and larger optical bandgap.

  19. Investigation of Temperature Dependent Optical Modes in GexAs35-xSe65 Thin Films: Structure Specific Raman, FIR and Optical Absorption Spectroscopy

    E-Print Network [OSTI]

    Khan, Pritam; Joshy, Abin; Sathe, Vasant; Deshpande, Uday; Adarsh, K V

    2015-01-01T23:59:59.000Z

    In this article, we present a comprehensive study of temperature and composition dependent Raman spectroscopy of GexAs35-xSe65 thin films to understand different structural units responsible for optical properties. Strikingly, our experimental results uncover the ratio of GeSe4/2 tetrahedral and AsSe3/2 pyramidal units in GexAs35-xSe65 thin films and their linear scaling relationship with temperature and x. An important notable outcome of our study is the formation of Se8 rings at lower temperatures. Our experimental results further provide interesting optical features, thermally and compositionally tunable optical absorption spectra. Detailed structure specific FIR data at room temperature also present direct information on the structural units in consistent with Raman data. We foresee that our studies are useful in determining the lightinduced response of these films and also for their potential applications in optics and optoelectronics.

  20. Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers

    E-Print Network [OSTI]

    Woodward, R I; Runcorn, T H; Hu, G; Torrisi, F; Kelleher, E J R; Hasan, T

    2015-01-01T23:59:59.000Z

    We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.

  1. NMR characterization of sulphur substitution effects in the KxFe2-ySe2-zSz high-Tc superconductor

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

    Torchetti, D. A.; Imai, T.; Lei, H. C.; Petrovic, C.

    2012-04-01T23:59:59.000Z

    We present a?? Se NMR study of the effect of S substitution in the high-Tc superconductor KxFe2-ySe2-zSz in a temperature range up to 250 K. We examine two S concentrations, with z=0.8 (Tc~ 26 K) and z=1.6 (nonsuperconducting). The samples containing sulphur exhibit broader NMR line shapes than the KxFe?Se? sample due to local disorder in the Se environment. Our Knight shift ??K data indicate that in all samples, uniform spin susceptibility decreases with temperature, and that the magnitude of the Knight shift itself decreases with increased S concentration. In addition, S substitution progressively suppresses low-frequency spin fluctuations. None ofmore »the samples exhibit an enhancement of low-frequency antiferromagnetic spin fluctuations near Tc in 1/T?T, as seen in FeSe.« less

  2. NMR characterization of sulphur substitution effects in the KxFe2-ySe2-zSz high-Tc superconductor

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

    Torchetti, D. A.; Imai, T.; Lei, H. C.; Petrovic, C.

    2012-04-01T23:59:59.000Z

    We present a?? Se NMR study of the effect of S substitution in the high-Tc superconductor KxFe2-ySe2-zSz in a temperature range up to 250 K. We examine two S concentrations, with z=0.8 (Tc~ 26 K) and z=1.6 (nonsuperconducting). The samples containing sulphur exhibit broader NMR line shapes than the KxFe?Se? sample due to local disorder in the Se environment. Our Knight shift ??K data indicate that in all samples, uniform spin susceptibility decreases with temperature, and that the magnitude of the Knight shift itself decreases with increased S concentration. In addition, S substitution progressively suppresses low-frequency spin fluctuations. None of the samples exhibit an enhancement of low-frequency antiferromagnetic spin fluctuations near Tc in 1/T?T, as seen in FeSe.

  3. First-principles studies of the structural, electronic, and optical properties of a novel thorium compound Rb{sub 2}Th{sub 7}Se{sub 15}

    SciTech Connect (OSTI)

    Brik, M.G., E-mail: brik@fi.tartu.ee

    2014-04-01T23:59:59.000Z

    The structural, electronic, and optical properties of a recently synthesized thorium compound Rb{sub 2}Th{sub 7}Se{sub 15} have been calculated in the density functional theory framework for the first time. The calculated direct band gap was 1.471 eV (generalized gradient approximation) and 1.171 eV (local density approximation), with both results being close to the experimental result of 1.83 eV. High covalency/iconicity of the Th–Se/Rb–Se bonds was demonstrated by calculating effective Mulliken charges of all ions. The polarized calculations of the complex dielectric function are presented; dependence of the calculated index of refraction was fitted to the Sellmeyer equation in the wavelength range from 500 to 2500 nm. - Graphical abstract: Calculated band structure of Rb{sub 2}Th{sub 7}Se{sub 15}. - Highlights: • The first theoretical analysis of the Rb{sub 2}Th{sub 7}Se{sub 15} properties is reported. • Structural, electronic and optical properties of Rb{sub 2}Th{sub 7}Se{sub 15} were calculated. • An indirect character of Rb{sub 2}Th{sub 7}Se{sub 15} band gap was confirmed. • Dependence of the refractive index on the wavelength was calculated.

  4. Influence of Damp Heat on the Electrical, Optical, and Morphological Properties of Encapsulated CuInGaSe2 Devices

    SciTech Connect (OSTI)

    Sundaramoorthy, R.; Pern, F. J.; Teeter, G.; Li, Jian V.; Young, M.; Kuciauskas, D.; Call, N.; Yan, F.; To, B.; Johnston, S.; Noufi, R.; Gessert, T. A.

    2011-01-01T23:59:59.000Z

    CuInGaSe{sub 2} (CIGS) devices, encapsulated with different backsheets having different water vapor transmission rates (WVTR), were exposed to damp heat (DH) at 85 C and 85% relative humidity (RH) and characterized periodically to understand junction degradation induced by moisture ingress. Performance degradation of the devices was primarily driven by an increase in series resistance within first 50 h of exposure, resulting in a decrease in fill factor and, accompanied loss in carrier concentration and widening of depletion width. Surface analysis of the devices after 700-h DH exposure showed the formation of Zn(OH){sub 2} from hydrolysis of the Al-doped ZnO (AZO) window layer by the moisture, which was detrimental to the collection of minority carriers. Minority carrier lifetimes observed for the CIGS devices using time resolved photoluminescence (TRPL) remained relatively long after DH exposure. By etching the DH-exposed devices and re-fabricating with new component layers, the performance of reworked devices improved significantly, further indicating that DH-induced degradation of the AZO layer and/or the CdS buffer was the primary performance-degrading factor.

  5. Electron-beam induced variation of surface profile in amorphous As{sub 20}Se{sub 80} films

    SciTech Connect (OSTI)

    Kaganovskii, Yu., E-mail: kagany@mail.biu.ac.il, E-mail: trunov.m@gmail.com [Department of Physics, Bar-Ilan University, Ramat-Gan 52900 (Israel); Trunov, M. L., E-mail: kagany@mail.biu.ac.il, E-mail: trunov.m@gmail.com [Uzhgorod National University, Narodna sq. 3, Uzhgorod 88000 (Ukraine); Cserhati, C.; Beke, D. L. [Department of Solid State Physics, University of Debrecen, Bem sqr. 18/b, H-4026 Debrecen (Hungary); Lytvyn, P. M. [Institute of Semiconductor Physics, NAS of Ukraine, Kiev 03028 (Ukraine); Kökényesi, S. [Department of Experimental Physics, University of Debrecen, Bem sqr. 18/b, H-4026 Debrecen (Hungary)

    2014-05-14T23:59:59.000Z

    Unusual profile variation of holographic surface relief gratings is detected in thin (2??m) As{sub 20}Se{sub 80} chalcogenide films under e-beam irradiation: gratings of small periods were smoothed, whereas the gratings of larger periods increased their amplitudes. Irradiation was carried out in SEM, with 20?kV voltage and 8?nA current; the profiles of the irradiated areas were analyzed both by AFM and SEM. It is found that the kinetics of both flattening and growth followed by exponential law and took place due to lateral mass transport accelerated by e-irradiation. It is shown that the profile variation is mainly caused by competition between capillary forces and “chemical” forces induced by broken and deformed atomic bonds under e-beam irradiation. The kinetics of profile variation was calculated assuming that the mechanism of e-beam induced mass transfer is volume diffusion. The diffusion coefficients were estimated from the experimental data using theoretical expressions derived.

  6. Structural, Optical and Electrical Properties of PbSe Nanocrystal Solids Treated Thermally or with Simple Amines

    SciTech Connect (OSTI)

    Law, M.; Luther, J. M.; Song, Q.; Hughes, B. K.; Perkins, C. L.; Nozik, A. J.

    2008-01-01T23:59:59.000Z

    We describe the structural, optical, and electrical properties of films of spin-cast, oleate-capped PbSe nanocrystals that are treated thermally or chemically in solutions of hydrazine, methylamine, or pyridine to produce electronically coupled nanocrystal solids. Postdeposition heat treatments trigger nanocrystal sintering at {approx}200 C, before a substantial fraction of the oleate capping group evaporates or pyrolyzes. The sintered nanocrystal films have a large hole density and are highly conductive. Most of the amine treatments preserve the size of the nanocrystals and remove much of the oleate, decreasing the separation between nanocrystals and yielding conductive films. X-ray scattering, X-ray photoelectron and optical spectroscopy, electron microscopy, and field-effect transistor electrical measurements are used to compare the impact of these chemical treatments. We find that the concentration of amines adsorbed to the NC films is very low in all cases. Treatments in hydrazine in acetonitrile remove only 2-7% of the oleate yet result in high-mobility n-type transistors. In contrast, ethanol-based hydrazine treatments remove 85-90% of the original oleate load. Treatments in pure ethanol strip 20% of the oleate and create conductive p-type transistors. Methylamine- and pyridine-treated films are also p-type. These chemically treated films oxidize rapidly in air to yield, after short air exposures, highly conductive p-type nanocrystal solids. Our results aid in the rational development of solar cells based on colloidal nanocrystal films.

  7. Improved Energy Conversion Efficiency in Wide-Bandgap Cu(In,Ga)Se2 Solar Cells: Preprint

    SciTech Connect (OSTI)

    Contreras, M.; Mansfield, L.; Egaas, B.; Li, J.; Romero, M.; Noufi, R.; Rudiger-Voigt, E.; Mannstadt, W.

    2011-07-01T23:59:59.000Z

    This report outlines improvements to the energy conversion efficiency in wide bandgap (Eg>1.2 eV) solar cells based on CuIn1-xGaxSe2. Using (a) alkaline containing high temperature glass substrates, (b) elevated substrate temperatures 600?C-650?C and (c) high vacuum evaporation from elemental sources following NREL's three-stage process, we have been able to improve the performance of wider bandgap solar cells with 1.218% for absorber bandgaps ~1.30 eV and efficiencies ~16% for bandgaps up to ~1.45 eV. In comparing J-V parameters in similar materials, we establish gains in the open-circuit voltage and, to a lesser degree, the fill factor value, as the reason for the improved performance. The higher voltages seen in these wide gap materials grown at high substrate temperatures may be due to reduced recombination at the grain boundary of such absorber films. Solar cell results, absorber materials characterization, and experimental details are reported.

  8. Bright three-band white light generated from CdSe/ZnSe quantum dot-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode with high color rendering index

    SciTech Connect (OSTI)

    Jang, Ho Seong; Kwon, Byoung-Hwa; Jeon, Duk Young [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yang, Heesun [Department of Materials Science and Engineering, Hongik University, 72-1, Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of)

    2009-10-19T23:59:59.000Z

    In this study, bright three-band white light was generated from the CdSe/ZnSe quantum dot (QD)-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode (WLED). The CdSe/ZnSe core/shell structure was confirmed by energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The CdSe/ZnSe QDs showed high quantum efficiency (79%) and contributed to the high luminous efficiency ({eta}{sub L}) of the fabricated WLED. The WLED showed bright natural white with excellent color rendering property ({eta}{sub L}=26.8 lm/W, color temperature=6140 K, and color rendering index=85) and high stability against the increase in forward bias currents from 20 to 70 mA.

  9. MatSE 452 Fall 2011 Course Description: The main goals of the course are to introduce and provide hands-on

    E-Print Network [OSTI]

    Weaver, John H.

    these error bars. #12;Guidelines to Preparing Laboratory Reports MatSE 452 Fall 2011 The following guidelines) Abstract: The abstract is to be placed on Page 1, in block style with no paragraph indentation and in bold

  10. THESIS PROJECT: REGISTRATION NOTE!! The form is to be handed in to the thesis project coordinator, see www.it.uu.se/edu/exjobb

    E-Print Network [OSTI]

    Andersson, Arne

    1 (2) THESIS PROJECT: REGISTRATION NOTE!! The form is to be handed in to the thesis project coordinator, see www.it.uu.se/edu/exjobb Uppsala University Graduation Degree: Bachelor Master Department: ............................................................................................................................................................................. ................................................................................................................................... The project will be carried out

  11. Electronic Structure of the Topological Insulator Bi[subscript 2]Se[subscript 3] Using Angle-Resolved Photoemission Spectroscopy: Evidence for a Nearly Full Surface Spin Polarization

    E-Print Network [OSTI]

    Pan, Z.-H.

    We performed high-resolution spin- and angle-resolved photoemission spectroscopy studies of the electronic structure and the spin texture on the surface of Bi[subscript 2]Se[subscript 3], a model TI. By tuning the photon ...

  12. Plan estratgico UTC El Plan Estratgico de la Unidad Tcnica de Calidad (UTC) , se enmarca dentro del proceso de derivacin que supone que cada

    E-Print Network [OSTI]

    Escolano, Francisco

    Plan estratégico UTC El Plan Estratégico de la Unidad Técnica de Calidad (UTC) , se enmarca dentro) 96 590 9414 Fax: (+34) 96 590 9678 Unidad Técnica de Calidad #12;

  13. Atomic and electronic structures of single-layer FeSe on SrTiO3(001): The role of oxygen deficiency

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

    Bang, Junhyeok; Li, Zhi; Sun, Y. Y.; Samanta, Amit; Zhang, Y. Y.; Zhang, Wenhao; Wang, Lili; Chen, X.; Ma, Xucun; Xue, Q.-K.; Zhang, S. B.

    2013-06-01T23:59:59.000Z

    Using first-principles calculation, we propose an interface structure for single triple-layer FeSe on the SrTiO3(001) surface, a high-Tc superconductor found recently. The key component of this structure is the oxygen deficiency on the top layer of the SrTiO3 substrate, as a result of Se etching used in preparing the high-Tc samples. The O vacancies strongly bind the FeSe triple layer to the substrate giving rise to a (2×1) reconstruction, as observed by scanning tunneling microscopy. The enhanced binding correlates to the significant increase of Tc observed in experiment. The O vacancies also serve as the source of electron doping, which modifies the Fermi surface of the first FeSe layer by filling the hole pocket near the center of the surface Brillouin zone, as suggested from angle-resolved photoemission spectroscopy measurement.

  14. Resolucin de 25 de febrero de 2009 del Vicerrectorado de Relaciones Internacionales y Cooperacin de la Universidad de Alicante, por la que se revoca

    E-Print Network [OSTI]

    Escolano, Francisco

    de la Universidad de Alicante, por la que se revoca la beca "Doctorado en Bienestar social y, resuelve revocar con efectos de 1 de febrero de 2009, la beca "Doctorado en Bienestar social y

  15. Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells

    E-Print Network [OSTI]

    Cao, Guozhong

    ) as a derivative of dye-sensitized solar cells (DSCs) have attracted considerable attention and been regardedMesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells Ru Zhou for a CdS/CdSe quantum dot (QD) co-sensitized solar cell, which was constructed with the mesoporous TiO2

  16. Stereo-Active Lone-Pair Control on the Ferromagnetic Behavior in VO(SeO2OH)2:A new acentric ferromagnetic material

    SciTech Connect (OSTI)

    Kim, Sang-Hwan [University of Houston, Houston; Yeon, J [University of Houston, Houston; Safa-Sefat, Athena [ORNL; Mandrus, David [ORNL; Halasyamani, P Shiv [University of Houston, Houston

    2010-01-01T23:59:59.000Z

    A new acentric ferromagnetic material, VO(SeO{sub 2}OH){sub 2}, has been synthesized and characterized by single crystal X-ray diffraction, second harmonic generation (SHG), and magnetization measurements. The crystal structure of VO(SeO{sub 2}OH){sub 2} consists of linear chains of corner-shared V{sup 4+}O{sub 6} octahedra that are connected by SeO{sub 2}OH groups. The material exhibits a weak SHG efficiency, comparable to {alpha}-SiO{sub 2}, and a ferromagnetic transition (T{sub C}) at 2.5 K with a saturated magnetic moment of 1.09 {mu}B per formula unit ({mu}B/FU). The origin of the ferromagnetism is explained by the suppression of the antiferromagnetic superexchange (SE) and supersuper-exchange (SSE) interactions in the intra-chain and inter-chain magnetic interactions, respectively. In addition, using first principles density functional theory (DFT) calculations, we show that the SSE interactions depend on the O(2)-Se{sup 4+}-O(3) angle. As we demonstrate, the stereoactive lone-pair on Se{sup 4+} is the driving force for the inter-chain ferromagnetic interactions.

  17. The influence of air temperature inversions on snowmelt and glacier mass-balance simulations, Ammassalik island, SE Greenland

    SciTech Connect (OSTI)

    Mernild, Sebastian Haugard [Los Alamos National Laboratory; Liston, Glen [COLORADO STATE UNIV.

    2009-01-01T23:59:59.000Z

    In many applications, a realistic description of air temperature inversions is essential for accurate snow and glacier ice melt, and glacier mass-balance simulations. A physically based snow-evolution modeling system (SnowModel) was used to simulate eight years (1998/99 to 2005/06) of snow accumulation and snow and glacier ice ablation from numerous small coastal marginal glaciers on the SW-part of Ammassalik Island in SE Greenland. These glaciers are regularly influenced by inversions and sea breezes associated with the adjacent relatively low temperature and frequently ice-choked fjords and ocean. To account for the influence of these inversions on the spatiotemporal variation of air temperature and snow and glacier melt rates, temperature inversion routines were added to MircoMet, the meteorological distribution sub-model used in SnowModel. The inversions were observed and modeled to occur during 84% of the simulation period. Modeled inversions were defined not to occur during days with strong winds and high precipitation rates due to the potential of inversion break-up. Field observations showed inversions to extend from sea level to approximately 300 m a.s.l., and this inversion level was prescribed in the model simulations. Simulations with and without the inversion routines were compared. The inversion model produced air temperature distributions with warmer lower elevation areas and cooler higher elevation areas than without inversion routines due to the use of cold sea-breeze base temperature data from underneath the inversion. This yielded an up to 2 weeks earlier snowmelt in the lower areas and up to 1 to 3 weeks later snowmelt in the higher elevation areas of the simulation domain. Averaged mean annual modeled surface mass-balance for all glaciers (mainly located above the inversion layer) was -720 {+-} 620 mm w.eq. y{sup -1} for inversion simulations, and -880 {+-} 620 mm w.eq. y{sup -1} without the inversion routines, a difference of 160 mm w.eq. y{sup -1}. The annual glacier loss for the two simulations was 50.7 x 10{sup 6} m{sup 3} y{sup -1} and 64.4 x 10{sup 6} m{sup 3} y{sup -1} for all glaciers - a difference of {approx}21%. The average equilibrium line altitude (ELA) for all glaciers in the simulation domain was located at 875 m a.s.l. and at 900 m a.s.l. for simulations with or without inversion routines, respectively.

  18. Polycrystalline CuInSe{sub 2} and CdTe solar cells. Annual subcontract report, April 15, 1992--April 14, 1993

    SciTech Connect (OSTI)

    Dhere, N.G. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

    1994-08-01T23:59:59.000Z

    The principal objective of the research project is to develop processes for the fabrication of cadmium-telluride, CdTe, and copper-indium-gallium-diselenide, Cu(In{sub 1{minus}x}Ga{sub x})Se{sub 2}, polycrystalline-thin-film solar cells using techniques that can be scaled-up for economic manufacture on a large scale. The aims are to fabricate CdTe solar cells using Cd and Te layers sputtered from elemental targets; to promote the interdiffusion between Cd/Te layers, CdTe phase formation, and grain growth; to utilize non-toxic selenization so as to avoid the use of extremely toxic H{sub 2}Se in the fabrication of Cu(In{sub l{minus}x}Ga{sub x})Se{sub 2} thin-film solar cells; to optimize selenization parameters; to improve adhesion; to minimize residual stresses; to improve the uniformity, stoichiometry, and morphology of CdTe and Cu(In{sub 1{minus}x}Ga{sub x})Se{sub 2} thin films, and the efficiency of CdTe and Cu(In{sub 1{minus}x}Ga{sub x})Se{sub 2} solar cells.

  19. Composition-optimized TiO{sub 2}/CdS{sub x}Se{sub 1-x} core/shell nanowire arrays for photoelectrochemical hydrogen generation

    SciTech Connect (OSTI)

    Ai, Guanjie; Mo, Rong; Xu, Hang; Chen, Qian; Yang, Sui; Li, Hongxing, E-mail: hongxinglee@xtu.edu.cn; Zhong, Jianxin [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronics, Xiangtan University, Hunan 411105 (China)

    2014-11-07T23:59:59.000Z

    Core/shell heterostructured TiO{sub 2}/CdS{sub x}Se{sub 1-x} nanowire arrays (NWAs) were prepared via physical vapor deposition of CdS{sub x}Se{sub 1-x} layer onto the hydrothermal pre-grown TiO{sub 2} NWAs with FTO as conductive substrate. By change the sulfur content (x) in the TiO{sub 2}/CdS{sub x}Se{sub 1-x} nano-composites, it was observed that the light absorption edge can be gradually tuned within a broad wavelength from 540 to 710?nm. When used as photoanodes for hydrogen generation, the as-prepared TiO{sub 2}/CdS{sub x}Se{sub 1-x} NWAs show much higher photoelectroncatalytic activity than the pristine TiO{sub 2} NWAs. Moreover, the TiO{sub 2}/CdS{sub x}Se{sub 1-x} photoelectrode with x?=?0.52 exhibited the highest photocurrent level and outstanding stability, which is more suitable for long-time hydrogen generation. This study may be useful in the design of alloy hetrostructure photoelectrodes with optimal chemical composition toward the more efficient solar conversion devices.

  20. Effect of sintering in ball-milled K{sub 2}Bi{sub 8}Se{sub 13} thermoelectric nano-composites

    SciTech Connect (OSTI)

    Hatzikraniotis, E. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)] [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Ioannou, M. [Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia (Cyprus)] [Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia (Cyprus); Chrissafis, K. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)] [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chung, D.Y. [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Paraskevopoulos, K.M. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)] [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kyratsi, Th., E-mail: kyratsi@ucy.ac.cy [Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia (Cyprus)

    2012-09-15T23:59:59.000Z

    K{sub 2}Bi{sub 8}Se{sub 13} has many attractive features for thermoelectric applications. Recently, K{sub 2}Bi{sub 8}Se{sub 13}-based nanocomposite materials, consisting of nano-crystalline, micro-crystalline and amorphous phases, have been fabricated based on powder technology techniques. The Seebeck coefficient has been enhanced while the thermal conductivity has been decreased presenting, thus, interesting behavior. The behavior of the materials under heat treatment conditions is now of interest, as the application of sintering process is necessary for the development of thermoelectric modules. In this work, the crystallization of the K{sub 2}Bi{sub 8}Se{sub 13}-based nano-composites is studied using Differential Scanning Calorimetry. The results show that crystallization follows a multiple-step process with different activation energies. The thermoelectric properties are also discussed in the range that crystallization occurs. - Graphical Abstract: {beta}-K{sub 2}Bi{sub 8}Se{sub 13}-based nanocomposites follow a multiple-step crystallization process. Highlights: Black-Right-Pointing-Pointer K{sub 2}Bi{sub 8}Se{sub 13}-based composites consisting of nanocrystalline and amorphous phases. Black-Right-Pointing-Pointer Sintering results multiple-step crystallization with variable activation energies. Black-Right-Pointing-Pointer Thermoelectric properties follow a step-like behavior during sintering. Black-Right-Pointing-Pointer Properties are attributed to the strain relaxation, nucleation and grain growth.

  1. A one-dimensional Fickian model to predict the Ga depth profiles in three-stage Cu(In,Ga)Se{sub 2}

    SciTech Connect (OSTI)

    Rodriguez-Alvarez, H., E-mail: humberto.rodriguez@helmholtz-berlin.de [International Iberian Nanotechnology Laboratory, Avenida Mestre Jose Veiga s/n, 4715-330 Braga (Portugal); Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Mainz, R. [Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Sadewasser, S. [International Iberian Nanotechnology Laboratory, Avenida Mestre Jose Veiga s/n, 4715-330 Braga (Portugal)

    2014-05-28T23:59:59.000Z

    We present a one-dimensional Fickian model that predicts the formation of a double Ga gradient during the fabrication of Cu(In,Ga)Se{sub 2} thin films by three-stage thermal co-evaporation. The model is based on chemical reaction equations, structural data, and effective Ga diffusivities. In the model, the Cu(In,Ga)Se{sub 2} surface is depleted from Ga during the deposition of Cu-Se in the second deposition stage, leading to an accumulation of Ga near the back contact. During the third deposition stage, where In-Ga-Se is deposited at the surface, the atomic fluxes within the growing layer are inverted. This results in the formation of a double Ga gradient within the Cu(In,Ga)Se{sub 2} layer and reproduces experimentally observed Ga distributions. The final shape of the Ga depth profile strongly depends on the temperatures, times and deposition rates used. The model is used to evaluate possible paths to flatten the marked Ga depth profile that is obtained when depositing at low substrate temperatures. We conclude that inserting Ga during the second deposition stage is an effective way to achieve this.

  2. Understanding the electronic structure of CdSe quantum dot-fullerene (C{sub 60}) hybrid nanostructure for photovoltaic applications

    SciTech Connect (OSTI)

    Sarkar, Sunandan; Rajbanshi, Biplab; Sarkar, Pranab, E-mail: pranab.sarkar@visva-bharati.ac.in [Department of Chemistry, Visva-Bharati University, Santiniketan 731235 (India)

    2014-09-21T23:59:59.000Z

    By using the density-functional tight binding method, we studied the electronic structure of CdSe quantum dot(QD)-buckminsterfullerene (C{sub 60}) hybrid systems as a function of both the size of the QD and concentration of the fullerene molecule. Our calculation reveals that the lowest unoccupied molecular orbital energy level of the hybrid CdSeQD-C{sub 60} systems lies on the fullerene moiety, whereas the highest occupied molecular orbital (HOMO) energy level lies either on the QD or the fullerene depending on size of the CdSe QD. We explored the possibility of engineering the energy level alignment by varying the size of the CdSe QD. With increase in size of the QD, the HOMO level is shifted upward and crosses the HOMO level of the C{sub 60}-thiol molecule resulting transition from the type-I to type-II band energy alignment. The density of states and charge density plot support these types of band gap engineering of the CdSe-C{sub 60} hybrid systems. This type II band alignment indicates the possibility of application of this nanohybrid for photovoltaic purpose.

  3. Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991

    SciTech Connect (OSTI)

    Sites, J.R. [Colorado State Univ., Fort Collins, CO (United States)

    1991-12-31T23:59:59.000Z

    The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.

  4. The energy band structure of A{sub x}Fe{sub 2}Se{sub 2} (A = K, Rb) superconductors

    SciTech Connect (OSTI)

    Zabidi, Noriza A. [Physics Department, Centre for Defence Foundation Studies, Universiti Pertahanan Nasional Malaysia, Kuala Lumpur 59200 (Malaysia); Azhan, Muhd. Z. [Defence Science Department, Faculty of Defence Science and Technology, Universiti Pertahanan Nasional Malaysia, Kuala Lumpur 59200 (Malaysia); Rosli, A. N. [Faculty of Science and Technology, Universiti Sains Islam Malaysia, Nilai 71800, Negeri Sembilan (Malaysia); Shrivastava, Keshav N. [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-03-05T23:59:59.000Z

    We study the band structure of antiferromagnetic A{sub x}Fe{sub 2}Se{sub 2} (A = K, Rb) superconductors by using first-principles electronic structure calculations which is density functional theory. In the vicinity of iron-vacancy, we identify the valence electrons of A{sub x}Fe{sub 2}Se{sub 2} will be filled up to the Fermi level and no semiconducting gap is observed. Hence, the A{sub x}Fe{sub 2}Se{sub 2} is a metallic instead of semiconducting which leads to superconductivity in the orbital-selective Mott phase. Similarly, there is non-vanishing density of states at the Fermi level.

  5. ZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY M.A. Contreras, 2

    E-Print Network [OSTI]

    Sites, James R.

    of the deposition rate control. Figure 1. Total-area current-voltage data for MgF2/ZnO/ZnS(O,OH)/CIGS/Mo solar cellZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY 1 M.A. Contreras, 2 T. Nakada, 2 M of 18.6% for Cu(In,Ga)Se2 solar cells that incorporate a ZnS(O,OH) buffer layer as an alternative to Cd

  6. Lead (II) selenite halides Pb{sub 3}(SeO{sub 3}){sub 2}X{sub 2} (X = Br, I): Synthesis and crystal structure

    SciTech Connect (OSTI)

    Berdonosov, P. S., E-mail: berdonosov@inorg.chem.msu.ru; Olenev, A. V.; Dolgikh, V. A. [Moscow State University (Russian Federation)

    2012-03-15T23:59:59.000Z

    Two lead selenite halides, Pb{sub 3}(SeO{sub 3}){sub 2}Br{sub 2} and Pb{sub 3}(SeO{sub 3}){sub 2}I{sub 2}, have been prepared by solid-phase synthesis and structurally characterized. These compounds are isotypic and can be considered 3D with a microporous framework composed of lead polyhedra (distorted Archimedean antiprisms formed by oxygen and halogen atoms). The framework contains channels oriented in the [010] direction. These channels contain selenium atoms, which are bound with framework oxygen atoms belonging to different lead polyhedra.

  7. Solar-energy conversion by combined photovoltaic converters with CdTe and CuInSe{sub 2} base layers

    SciTech Connect (OSTI)

    Khrypunov, G. S., E-mail: khrip@ukr.net; Sokol, E. I. [National Technical University “Kharkiv Polytechnic Institute” (Ukraine); Yakimenko, Yu. I. [National Technical University “Kyiv Polytechnic Institute”, Research Institute of Applied Electronics (Ukraine); Meriuts, A. V. [National Technical University “Kharkiv Polytechnic Institute” (Ukraine); Ivashuk, A. V. [National Technical University “Kyiv Polytechnic Institute”, Research Institute of Applied Electronics (Ukraine); Shelest, T. N. [National Technical University “Kharkiv Polytechnic Institute” (Ukraine)

    2014-12-15T23:59:59.000Z

    The possibility of the combined use of bifacial thin-film solar cells based on CdTe and frontal solar cells with a CuInSe{sub 2} base layer in tandem structures is experimentally confirmed. It is found that, for the use of bifacial solar cells based on cadmium telluride in a tandem structure, the optimal thickness of their base layer should be 1 ?m. The gain in the efficiency of the tandem structure, compared with an individual CuInSe{sub 2}-based solar cell, is 1.8% in the case of series-connected solar cells and 1.3%, for parallel-connected.

  8. Dispersion of the linear and nonlinear optical susceptibilities of the CuAl(S{sub 1?x}Se{sub x}){sub 2} mixed chaclcopyrite compounds

    SciTech Connect (OSTI)

    Reshak, A. H., E-mail: maalidph@yahoo.com [New Technologies - Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Brik, M. G. [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Institute of Physics, University of Tartu, Ravila 14C, Tartu 50411 (Estonia); Auluck, S. [Council of Scientific and Industrial Research—National Physical Laboratory Dr. K S Krishnan Marg, New Delhi 110012 (India)

    2014-09-14T23:59:59.000Z

    Based on the electronic band structure, we have calculated the dispersion of the linear and nonlinear optical susceptibilities for the mixed CuAl(S{sub 1?x}Se{sub x}){sub 2} chaclcopyrite compounds with x?=?0.0, 0.25, 0.5, 0.75, and 1.0. Calculations are performed within the Perdew-Becke-Ernzerhof general gradient approximation. The investigated compounds possess a direct band gap of about 2.2?eV (CuAlS{sub 2}), 1.9?eV (CuAl(S{sub 0.75}Se{sub 0.25}){sub 2}), 1.7?eV (CuAl(S{sub 0.5}Se{sub 0.5}){sub 2}), 1.5?eV (CuAl(S{sub 0.25}Se{sub 0.75}){sub 2}), and 1.4?eV (CuAlSe{sub 2}) which tuned to make them optically active for the optoelectronics and photovoltaic applications. These results confirm that substituting S by Se causes significant band gaps' reduction. The optical function's dispersion ?{sub 2}{sup xx}(?) and ?{sub 2}{sup zz}(?)/?{sub 2}{sup xx}(?), ?{sub 2}{sup yy}(?), and ?{sub 2}{sup zz}(?) was calculated and discussed in detail. To demonstrate the effect of substituting S by Se on the complex second-order nonlinear optical susceptibility tensors, we performed detailed calculations for the complex second-order nonlinear optical susceptibility tensors, which show that the neat parents compounds CuAlS{sub 2} and CuAlSe{sub 2} exhibit | ?{sub 123}{sup (2)}(?2?;?;?) | as the dominant component, while the mixed alloys exhibit | ?{sub 111}{sup (2)}(?2?;?;?) | as the dominant component. The features of | ?{sub 123}{sup (2)}(?2?;?;?) | and | ?{sub 111}{sup (2)}(?2?;?;?) | spectra were analyzed on the basis of the absorptive part of the corresponding dielectric function ?{sub 2}(?) as a function of both ?/2 and ?.

  9. Syntheses, crystal structures and characterizations of BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2}

    SciTech Connect (OSTI)

    Jiang Hailong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China); Feng Meiling [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China); Mao Jianggao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China)]. E-mail: mjg@ms.fjirsm.ac.cn

    2006-06-15T23:59:59.000Z

    Two new barium zinc selenite and tellurite, namely, BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2}, have been synthesized by the solid state reaction. The structure of BaZn(SeO{sub 3}){sub 2} features double chains of [Zn(SeO{sub 3}){sub 2}]{sup 2-} anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn{sub 2}(TeO{sub 3}){sub 2}Cl{sub 3}]{sup 3-} anions in BaZn(TeO{sub 3})Cl{sub 2} are formed by Zn{sub 3}Te{sub 3} rings in which each tellurite group connects with three ZnO{sub 3}Cl tetrahedra. BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2} are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements. -- Graphical abstract: Two new barium zinc selenite and tellurite, namely, BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2}, have been synthesized by solid state reaction. The structure of BaZn(SeO{sub 3}){sub 2} features 1D double chains of [Zn(SeO{sub 3}){sub 2}]{sup 2-} anions composed of four- and eight-member rings which are alternatively along a-axis. The 1D double chains of [Zn{sub 2}(TeO{sub 3}){sub 2}Cl{sub 3}]{sup 3-} anions in BaZn(TeO{sub 3})Cl{sub 2} are formed by Zn{sub 3}Te{sub 3} rings in which each tellurite group connects with one ZnO{sub 3}Cl and two ZnO{sub 2}Cl{sub 2} tetrahedra. BaZn(SeO{sub 3}){sub 2} and BaZn(TeO{sub 3})Cl{sub 2} are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements.

  10. First Direct Double- Decay Q-Value Measurement of 82Se in Support of Understanding the Nature of the Neutrino

    SciTech Connect (OSTI)

    Lincoln, David L. [NSCL, Michigan State University, East Lansing; Holt, Jason D. [Technische Univ. Darmstadt/GSI/UTK/ORNL; Bollen, Georg [NSCL, Michigan State University, East Lansing; Brodeur, Maxime [NSCL, Michigan State University, East Lansing; Bustabad, Scott [NSCL, Michigan State University, East Lansing; Engel, Jonathan [University of North Carolina, Chapel Hill; Novario, Samuel J. [NSCL, Michigan State University, East Lansing; Redshaw, Matthew [NSCL, Michigan State Univ.,/Central Michigan Univ.-Mt. Pleasant; Ringle, Ryan [NSCL, Michigan State University, East Lansing; Schwarz, Stefan [NSCL, Michigan State University, East Lansing

    2013-01-01T23:59:59.000Z

    In anticipation of results from current and future double- decay studies, we report a measurement resulting in a 82Se double- decay Q value of 2997.9(3) keV, an order of magnitude more precise than the currently accepted value. We also present preliminary results of a calculation of the 82Se neutrinoless double- decay nuclear matrix element that corrects in part for the small size of the shell model single-particle space. The results of this work are important for designing next generation double- decay experiments and for the theoretical interpretations of their observations.

  11. Observation of an electron band above the Fermi level in FeTe?.??Se?.?? from in-situ surface doping

    SciTech Connect (OSTI)

    Zhang, P. [Chinese Academy of Sciences (CAS), Beijing (China); Gu, G. D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Richard, P. [Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Xu, N. [Chinese Academy of Sciences (CAS), Beijing (China); Paul Scherrer Inst. (PSI), Villigen (Switzerland); Xu, Y. -M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ma, J. [Chinese Academy of Sciences (CAS), Beijing (China); Qian, T. [Chinese Academy of Sciences (CAS), Beijing (China); Fedorov, A. V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Denlinger, J. D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ding, H. [Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-10-27T23:59:59.000Z

    We used in-situ potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe?.??Se?.??. The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily-electron-doped KFe??xSe? compound.

  12. Syntheses, crystal structures and optical properties of the first strontium selenium(IV) and tellurium(IV) oxychlorides: Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} and Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4}

    SciTech Connect (OSTI)

    Jiang Hailong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Mao Jianggao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)], E-mail: mjg@fjirsm.ac.cn

    2008-02-15T23:59:59.000Z

    Two new quaternary strontium selenium(IV) and tellurium(IV) oxychlorides, namely, Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} and Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4}, have been prepared by solid-state reaction. Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} features a three-dimensional (3D) network structure constructed from strontium(II) interconnected by Cl{sup -}, SeO{sub 3}{sup 2-} as well as Se{sub 2}O{sub 5}{sup 2-} anions. The structure of Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4} features a 3D network in which the strontium tellurium oxide slabs are interconnected by bridging Cl{sup -} anions. The diffuse reflectance spectrum measurements and results of the electronic band structure calculations indicate that both compounds are wide band-gap semiconductors. - Graphical abstract: Solid-state reactions of SrO, SrCl{sub 2}, and SeO{sub 2} or TeO{sub 2} in different molar ratios and under different temperatures lead to two new strontium selenium(IV) or tellurium(IV) oxychlorides with two different types of structures, namely, Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} and Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4}. Both compounds are wide band-gap semiconductors based on the diffuse reflectance spectra and the electronic band structures.

  13. Beta-decay of nuclei around Se-90. Search for signatures of a N=56 sub-shell closure relevant the r-process

    E-Print Network [OSTI]

    Quinn, M; Pereira, J; Surman, R; Arndt, O; Baumann, T; Becerril, A; Elliot, T; Estrade, A; Galaviz, D; Ginter, T; Hausmann, M; Hennrich, S; Kessler, R; Kratz, K -L; Lorusso, G; Mantica, P F; Matos, M; Moller, P; Montes, F; Pfeiffer, B; Portillo, M; Hennrich, S; Schatz, H; Schertz, F; Schnorrenberger, L; Smith, E; Stolz, A; Walters, W B; Wohr, A

    2011-01-01T23:59:59.000Z

    Nuclear structure plays a significant role on the rapid neutron capture process (r-process) since shapes evolve with the emergence of shells and sub-shells. There was some indication in neighboring nuclei that we might find examples of a new N=56 sub-shell, which may give rise to a doubly magic Se-90 nucleus. Beta-decay half lives of nuclei around Se-90 have been measured to determine if this nucleus has in fact a doubly-magic character. The fragmentation of Xe-136 beam at the National Superconducting Cyclotron Laboratory at Michigan State University was used to create a cocktail of nuclei in the A=90 region. We have measured the half lives of twenty-two nuclei near the r-process path in the A=90 region. The half lives of As-88 and Se-90 have been measured for the first time. The values were compared with theoretical predictions in the search for nuclear-deformation signatures of a N=56 sub-shell, and its possible role in the emergence of a potential doubly-magic Se-90. The impact of such hypothesis on the sy...

  14. Twin Cities Campus The Aurora Center for Advocacy & Education 128 Pleasant St. SE Office for Student Affairs Suite 117 Appleby Hall

    E-Print Network [OSTI]

    Blanchette, Robert A.

    Campus The Aurora Center for Advocacy & Education 128 Pleasant St. SE Office for Student Affairs Suite Prospective Volunteer, Thank you for your interest in being a volunteer with The Aurora Center for Advocacy and challenging work! The Aurora Center (TAC) provides free and confidential crisis intervention to victims

  15. Evolution of glass properties during a substitution of S by Se in Ge28Sb12S60-xSex glass Guillaume Guery1,2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Evolution of glass properties during a substitution of S by Se in Ge28Sb12S60-xSex glass network, Université de Bordeaux I, Avenue du Dr Schweitzer, 33608 Pessac Cedex, France. Keywords: Chalcogenide glass; Raman spectroscopy; X-ray photoelectron spectroscopy; Glass properties Author whom correspondence should

  16. travers la surface de contact chaude du sulfate de cuivre vers l'acide sulfurique : le phnomne Peltier semblerait donc se

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    phénomène Peltier semblerait donc se pro- duire ici en sens contraire de ce que l'on observe soit pour deux qui permettent de s'assurer que le phénomène de Peltier n'est pas compliqué d'actions chimiques

  17. 2) Certaines des substances essayes noircissent le revtement en argent de la cuve ; les cellules se dessinent alors sur ce fond, le noir-

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    que celle présumée par la formule et la pile s'échauffait, tantôt plus grande, et la pile se'énergie dégagée par la réaction chimique, alors qu'elle devrait être égale à la différence de celle-ci et de l les effets parasites (effet Peltier et Thomson) s'an- nulent et n'aura ient pu ab

  18. Rsum -Les films amorphes GeSe-j vapors obliquement ont une structure colonnaire trs marque. La contraction induite par photo-irradiation a t

    E-Print Network [OSTI]

    Boyer, Edmond

    -induced contraction of a-GeSe3 films has been studied with small-angle neutron scattering and scanning electron/. On illumination the films densify, and a previous small-angle neutron scattering (SANS) study /3/ showed. La contraction induite par photo-irradiation a été étudiée par diffusion des neutrons aux petits

  19. Suzuki batteries The '96 to present Suzuki DR650SE comes from the factory with a Yuasa YTX9BS battery. This is a

    E-Print Network [OSTI]

    Westall, James M.

    Suzuki batteries The '96 to present Suzuki DR650SE comes from the factory with a Yuasa YTX9BS battery. This is a highquality AGM (absorbed glass mat) type battery, which is sealed and maintenance free. AGM batteries last much longer than conventional floodedcell batteries in normal service

  20. Experimental investigation of exciton-LO-phonon couplings in CdSe/ZnS core/shell nanorods Holger Lange,1,* Mikhail Artemyev,2

    E-Print Network [OSTI]

    Nabben, Reinhard

    in the field of optoelectronics. CdSe nanorods have interest- ing properties, which lead to possible trioctylphosphine selenide in trioctylphos- phine oxide in the presence of hexadecylphosphonic acid as a surface- lected nanorod samples in a second step in a hexadecilamine/ trioctylphosphine oxide reaction mixture

  1. Hole drift mobility measurements in polycrystalline CuIn1-xGaxSe2 S. A. Dinca and E. A. Schiff

    E-Print Network [OSTI]

    Schiff, Eric A.

    mobility measurements on polycrystalline CuIn1-xGaxSe2 CIGS thin films incorporated into solar-cell of these properties is that solar cells fabricated from the thin- film polycrystalline materials have larger in a depletion region at the top interface with cadmium sulfide. 12 cells, originating in two laboratories, were

  2. Determination of the minority carrier diffusion length in compositionally graded Cu,,In,Ga...Se2 solar cells using electron beam induced

    E-Print Network [OSTI]

    Wu, Junqiao

    .1063/1.3291046 Cu In,Ga Se2 CIGS solar cells have achieved efficien- cies above 19% using a compositionally graded,S 2 films.7­9 However, the best CIGS solar cells have a compo- sitionally graded profile.10 The graded in compositionally graded CIGS solar cells. Energy dependent EBIC measurements were collected in the planar

  3. PHYSICAL REVIEW B 83, 104526 (2011) Fe Mossbauer study of magnetic ordering in superconducting K0.80Fe1.76Se2.00 single crystals

    E-Print Network [OSTI]

    Ryan, Dominic

    2011-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 83, 104526 (2011) 57 Fe M¨ossbauer study of magnetic ordering in superconducting 31 March 2011) The magnetic ordering of superconducting single crystals of K0.80Fe1.76Se2.00 has been studied between 10 and 550 K using 57 Fe M¨ossbauer spectroscopy. Despite being superconducting below Tsc

  4. PUBLISHED ONLINE: 10 MAY 2009 | DOI: 10.1038/NPHYS1270 Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3

    E-Print Network [OSTI]

    Loss, Daniel

    ARTICLES PUBLISHED ONLINE: 10 MAY 2009 | DOI: 10.1038/NPHYS1270 Topological insulators in Bi2Se3-Liang Qi3 , Xi Dai1 , Zhong Fang1 and Shou-Cheng Zhang3 * Topological insulators are new states of quantum of topologically protected states in two-dimensional and three-dimensional band insulators with large spin

  5. Discovery of a Topological Insulator Bi2Se3 with a Single Surface Dirac Cone. (DMR-0819860) IRG-A: M. Z. Hasan and R. J. Cava

    E-Print Network [OSTI]

    Petta, Jason

    Discovery of a Topological Insulator Bi2Se3 with a Single Surface Dirac Cone. (DMR-0819860) IRG field is applied. Recent research has uncovered a new class of insulators, called topological insulators spectroscopy (ARPES). In a new breakthrough, Hasan and Cava have now identified a second Topological Insulator

  6. Synthesis and structure of Cs[UO{sub 2}(SeO{sub 4})(OH)] . nH{sub 2}O (n = 1.5 or 1)

    SciTech Connect (OSTI)

    Serezhkina, L. B., E-mail: lserezh@ssu.samara.ru [Samara State University (Russian Federation); Peresypkina, E. V.; Virovets, A. V. [Russian Academy of Sciences, Institute of Inorganic Chemistry, Siberian Branch (Russian Federation); Pushkin, D. V.; Verevkin, A. G. [Samara State University (Russian Federation)

    2010-05-15T23:59:59.000Z

    The synthesis and single-crystal X-ray diffraction study of Cs[UO{sub 2}(SeO{sub 4})(OH)] . 1.5H{sub 2}O (I) and Cs[UO{sub 2}(SeO{sub 4})(OH)] . H{sub 2}O (II) are performed. Compound I crystallizes in the monoclinic crystal system, a = 7.2142(2) A, b = 14.4942(4) A, c = 8.9270(3) A, {beta} = 112.706(1){sup o}, space group P2{sub 1}/m, Z = 4, and R = 0.0222. Compound II is monoclinic, a = 8.4549(2) A, b = 11.5358(3) A, c = 9.5565(2) A, {beta} = 113.273(1){sup o}, space group P2{sub 1}/c, Z = 4, and R = 0.0219. The main structural units of crystals I and II are [UO{sub 2}(SeO{sub 4})(OH)]{sup -} layers which belong to the AT{sup 3}M{sup 2} crystal chemical group of uranyl complexes (A = UO{sub 2}{sup 2+}, T{sup 3} = SeO{sub 4}{sup 2-}, and M{sup 2} = OH{sup -}). In structure I, johannite-like layers are found. Structure II is a topological isomer of I. The two structures differ in the number of U(VI) atoms bound to the central atom by all bridging ligands.

  7. Sanders, J. E.; and Merguerian, Charles, 1992a, Directional history of Pleistocene glaciers inferred from features eroded on bedrock, New York metropolitan area, SE NY.

    E-Print Network [OSTI]

    Merguerian, Charles

    Sanders, J. E.; and Merguerian, Charles, 1992a, Directional history of Pleistocene glaciers inferred from features eroded on bedrock, New York metropolitan area, SE NY. If a glacier erodes bedrock, the usual perception is that the youngest glacier will obliterate all direction-of-flow evidence that any

  8. 22nd European Photovoltaic Solar Energy Conference, Milan, 3-7 September 2007 Cu(InGa)Se2 THIN-FILM SOLAR CELLS

    E-Print Network [OSTI]

    22nd European Photovoltaic Solar Energy Conference, Milan, 3-7 September 2007 Cu(InGa)Se2 THIN from the National Renewable Energy Laboratory and Global Solar Energy, we examined the life-cycle Cd-FILM SOLAR CELLS: COMPARATIVE LIFE-CYCLE ANALYSIS OF BUFFER LAYERS Vasilis M. Fthenakis and Hyung Chul Kim

  9. Oceanography | March 2012 213 O C E AN I C SPR E A D I N G CENT E R PRO C E S SE S |

    E-Print Network [OSTI]

    Girguis, Peter R.

    G R A M R E SE A RCH On the Potential for Bioenergy and Biofuels from Hydrothermal Vent Microbes are also well suited for bioenergy and biofuel production. Here, we discuss the utility and issues- scale biofuel production. IN SITU BIOENERGY GENERATION In the early twentieth century, scientists found

  10. Atomic and electronic structures of single-layer FeSe on SrTiO3(001): The role of oxygen deficiency

    SciTech Connect (OSTI)

    Bang, Junhyeok; Li, Zhi; Sun, Y. Y.; Samanta, Amit; Zhang, Y. Y.; Zhang, Wenhao; Wang, Lili; Chen, X.; Ma, Xucun; Xue, Q.-K.; Zhang, S. B.

    2013-06-01T23:59:59.000Z

    Using first-principles calculation, we propose an interface structure for single triple-layer FeSe on the SrTiO3(001) surface, a high-Tc superconductor found recently. The key component of this structure is the oxygen deficiency on the top layer of the SrTiO3 substrate, as a result of Se etching used in preparing the high-Tc samples. The O vacancies strongly bind the FeSe triple layer to the substrate giving rise to a (2×1) reconstruction, as observed by scanning tunneling microscopy. The enhanced binding correlates to the significant increase of Tc observed in experiment. The O vacancies also serve as the source of electron doping, which modifies the Fermi surface of the first FeSe layer by filling the hole pocket near the center of the surface Brillouin zone, as suggested from angle-resolved photoemission spectroscopy measurement.

  11. Seminario "Divulgacin de conocimientos en ciencias de la nutricin" DESTINADO A: Se trata de una actividad enfocada a todos los estudiantes del Grado

    E-Print Network [OSTI]

    Escolano, Francisco

    Seminario "Divulgación de conocimientos en ciencias de la nutrición" DESTINADO A: Se trata de una a cualquier estudiante y profesional de ciencias de la salud, hasta completar aforo. FECHA y HORA: martes 17 de diciembre de 2013, de 16:00 a 18:00. LUGAR: Salón de grados de la Facultad de Ciencias de la Salud

  12. Journal of Solid State Chemistry 180 (2007) 28772884 Cs4P2Se10: A new compound discovered with the application of

    E-Print Network [OSTI]

    Weliky, David

    2007-01-01T23:59:59.000Z

    ,b , Ratnasabapathy G. Iyera , Mercouri G. Kanatzidisa,b,1 , David P. Welikya,Ã a Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA b Department of Chemistry, Northwestern University by quenching the melt in ice water, and Cs4P2Se10 was recovered upon annealing. The static 31 P NMR spectrum

  13. PHYSICAL REVIEW B 88, 024515 (2013) Absence of zero-energy surface bound states in CuxBi2Se3 studied

    E-Print Network [OSTI]

    Peng, Haibing

    2013-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 88, 024515 (2013) Absence of zero-energy surface bound states in CuxBi2Se3 by an odd-parity full bulk superconducting gap and zero-energy surface Andreev bound states (Majorana fermions). A predicted consequence of such Majorana fermions is a peak in the zero-energy density of states

  14. Die Civil Academy ist ein gemeinsames Programm von BBE und BP Europa SE. Trger und Veranstalter der Civil Academy ist die BBE Geschftsstelle gemeinntzige GmbH.

    E-Print Network [OSTI]

    Reyle, Uwe

    Die Civil Academy ist ein gemeinsames Programm von BBE und BP Europa SE. Träger und Veranstalter der Civil Academy ist die BBE Geschäftsstelle gemeinnützige GmbH. Ausschreibung der 18. Civil Academy Civil Academy ­ Gutes auch gut tun! Du willst mit einer kreativen Idee die Welt zum Besseren verändern

  15. ZnS and ZnSe immersion gratings for astronomical high-resolution spectroscopy - evaluation of internal attenuation of bulk materials in the short NIR region

    SciTech Connect (OSTI)

    Ikeda, Y; Kobayashi, N; Kondo, S; Yasui, C; Kuzmenko, P J; Tokoro, H; Terada, H

    2009-08-12T23:59:59.000Z

    We measure the internal attenuation of bulk crystals of CVD-ZnS, CVD-ZnSe, Si, and GaAs, in the short near-infrared (sNIR) region to evaluate the possibility of astronomical immersion gratings with those high refractive index materials. We confirm that multispectral grade CVD-ZnS and CVD-ZnSe are best suited for the immersion gratings, with the smallest internal attenuation of {alpha}{sub att} = 0.01-0.03 cm{sup -1} among the major candidates. The measured attenuation is roughly in proportion to {lambda}{sup -2}, suggesting it is dominated by bulk scattering due to the polycrystalline grains rather than by absorption. The total transmittance in the immersion grating is estimated to be at least > 80 %, even for the spectral resolution of R = 300,000. Two potential problems, the scattered light by the bulk material and the degradation of the spectral resolution due to the gradient illumination in the diffracted beam, are investigated and found to be negligible for usual astronomical applications. Since the remaining problem, the difficulty of cutting grooves on CVD-ZnS and CVD-ZnSe, has recently been overcome by the nanoprecision fly-cutting technique, ZnS and ZnSe immersion gratings for astronomy can be technically realized.

  16. Microscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se2 Myriam Paire,1,2,3,4,a)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Microscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se2 thin films Myriam experiments on polycrystalline thin film solar cells. High level regime is reached, thanks to the micrometric grids are used on concentrator solar cells. The grid coverage is a trade-off between the decreased

  17. Structural and chemical investigations of CBD-and PVD-CdS buffer layers and interfaces in Cu(In,Ga)Se2-based thin film solar cells

    E-Print Network [OSTI]

    Romeo, Alessandro

    (In,Ga)Se2-based thin film solar cells D. Abou-Rasa,b,*, G. Kostorza , A. Romeob,1 , D. Rudmannb , A Available online 8 December 2004 Abstract It is known that high-efficiency thin film solar cells based on Cu in efficiencies of solar cells with CBD- and PVD-CdS buffer layers can partly be explained by referring

  18. Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3

    SciTech Connect (OSTI)

    Lee, J.J.; Schmitt, F.T.; Moore, R.G.; Johnston, S.; Cui, Y.-T.; Li, W.; Yi, M.; Liu, Z.K.; Hashimoto, M.; Zhang, Y.; Lu, D.H.; Devereaux, T.P.; Lee, D.-H.; Shen, Z.-X.

    2014-11-12T23:59:59.000Z

    Films of iron selenide (FeSe) one unit cell thick grown on strontium titanate (SrTiO3 or STO) substrates have recently shown superconducting energy gaps opening at temperatures close to the boiling point of liquid nitrogen (77 K), which is a record for the iron-based superconductors. The gap opening temperature usually sets the superconducting transition temperature Tc, as the gap signals the formation of Cooper pairs, the bound electron states responsible for superconductivity. To understand why Cooper pairs form at such high temperatures, we examine the role of the SrTiO3 substrate. Here we report high-resolution angle-resolved photoemission spectroscopy results that reveal an unexpected characteristic of the single-unit-cell FeSe/SrTiO3 system: shake-off bands suggesting the presence of bosonic modes, most probably oxygen optical phonons in SrTiO3, which couple to the FeSe electrons with only a small momentum transfer. Such interfacial coupling assists superconductivity in most channels, including those mediated by spin fluctuations. Our calculations suggest that this coupling is responsible for raising the superconducting gap opening temperature in single-unit-cell FeSe/SrTiO3.

  19. Characterization of Damp-Heat Degradation of CuInGaSe2 Solar Cell Components and Devices by (Electrochemical) Impedance Spectroscopy: Preprint

    SciTech Connect (OSTI)

    Pern, F. J. J.; Noufi, R.

    2011-09-01T23:59:59.000Z

    This work evaluated the capability of (electrochemical) impedance spectroscopy (IS, or ECIS as used here) to monitor damp heat (DH) stability of contact materials, CuInGaSe2 (CIGS) solar cell components, and devices. Cell characteristics and its variation of the CIGS devices were also examined by the ECIS.

  20. STUDEN T FIN ANCIAL AID AND SCHO LARSHIP S SE RVICE SUPPO RT SUCC ESS 1278 University of Oregon, Eugene OR 97403-1278 http://financialaid.uoregon.edu

    E-Print Network [OSTI]

    Oregon, University of

    STUDEN T FIN ANCIAL AID AND SCHO LARSHIP S SE RVICE SUPPO RT SUCC ESS 1278 University of Oregon #12;STUDEN T FIN ANCIAL AID AND SCHO LARSHIP S SE RVICE SUPPO RT SUCC ESS 1278 University of Oregon

  1. Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface

    SciTech Connect (OSTI)

    Zhang, Haijun; /Beijing, Inst. Phys.; Liu, Chao-Xing; /Tsinghua U., Beijing; Qi, Xiao-Liang; /Stanford U., Phys. Dept.; Dai, Xi; Fang, Zhong; /Beijing, Inst. Phys.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-02-24T23:59:59.000Z

    Topological insulators are new states of quantum matter in which surface states residing in the bulk insulating gap of such systems are protected by time-reversal symmetry. The study of such states was originally inspired by the robustness to scattering of conducting edge states in quantum Hall systems. Recently, such analogies have resulted in the discovery of topologically protected states in two-dimensional and three-dimensional band insulators with large spin-orbit coupling. So far, the only known three-dimensional topological insulator is Bi{sub x}Sb{sub 1-x}, which is an alloy with complex surface states. Here, we present the results of first-principles electronic structure calculations of the layered, stoichiometric crystals Sb{sub 2}Te{sub 3}, Sb{sub 2}Se{sub 3}, Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3}. Our calculations predict that Sb{sub 2}Te{sub 3}, Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} are topological insulators, whereas Sb{sub 2}Se{sub 3} is not. These topological insulators have robust and simple surface states consisting of a single Dirac cone at the point. In addition, we predict that Bi{sub 2}Se{sub 3} has a topologically non-trivial energy gap of 0.3 eV, which is larger than the energy scale of room temperature. We further present a simple and unified continuum model that captures the salient topological features of this class of materials.

  2. Synthesis, crystal structure and magnetic property of a new nickel selenite chloride: Ni{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2}

    SciTech Connect (OSTI)

    Shen Yueling [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China); Mao Jianggao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China)]. E-mail: mjg@ms.fjirsm.ac.cn; Jiang Hailong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, and the Graduate School of the Chinese Academy of Sciences, Fuzhou 350002 (China)

    2005-09-15T23:59:59.000Z

    The new nickel selenite chloride, Ni{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2}, was obtained by high-temperature solid state reaction of NiCl{sub 2}, Ni{sub 2}O{sub 3} and SeO{sub 2} in a 1:2:4molar ratio at 700{sup o}C in an evacuated quartz tube. Its structure was established by single-crystal X-ray diffraction. Ni{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} crystallizes in the triclinic system, space group P-1 (No. 2) with cell parameters of a=8.076(2), b=9.288(2), c=9.376(2)A, {alpha}=101.97(3), {beta}=105.60(3), {gamma}=91.83(3){sup o} and Z=2. All nickel(II) ions in Ni{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} are octahedrally coordinated by selenite oxygens or/and chloride anions (([Ni(1)O{sub 5}Cl], [Ni(2)O{sub 4}Cl{sub 2}], [Ni(3)O{sub 5}Cl], [Ni(4)O{sub 6}] and [Ni(5)O{sub 4}Cl]). The structure of the title compound features a condensed three-dimensional (3D) network built by Ni(II) ions interconnected by SeO{sub 3}{sup 2-} anions as well as Cl{sup -} anions. Magnetic property measurements show strong antiferromagnetic interaction between nickel(II) ions.

  3. Synthesis, characterization, and anomalous dielectric and conductivity performance of one-dimensional (bdaH)InSe{sub 2} (bda = 1,4-butanediamine)

    SciTech Connect (OSTI)

    Du, Ke-Zhao; Hu, Wan-Biao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China) [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Hu, Bing; Guan, Xiang-Feng [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)] [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Xiao-Ying, E-mail: xyhuang@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)] [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2011-11-15T23:59:59.000Z

    Graphical abstract: Anomalous dielectric and conductivity performance have been observed in the organic-containing indium selenide (bdaH)InSe{sub 2}, which are attributed to the water molecules existing in the crystal boundary rather than phase transition. Highlights: {yields} The title compound is the first example of organic-containing one-dimensional indium selenide. {yields} The anomalous dielectric peak is attributed to water molecules in crystal boundary. {yields} The inorganic and organic components of the title compound are connected via hydrogen bonding to form a supramolecular three-dimensional network. -- Abstract: A new indium selenide, namely (bdaH)InSe{sub 2} (1) (bda = 1,4-butanediamine) has been solvothermally synthesized and structurally characterized. It belongs to the non-centrosymmetric space group Fdd2. Its structure features an infinite one-dimensional anionic chain of [InSe{sub 2}]{sub n}{sup n-} with monoprotonated [bdaH]{sup +} as charge compensating cation. The organic [bdaH]{sup +} cations are joined into a supramolecular one-dimensional chain via N-H...N hydrogen bonding, which further interacts with the inorganic chain via N-H...Se and C-H...Se hydrogen bonding, forming a supramolecular three-dimensional network. Based on such a well-defined structure, the thermal stability, optical, conductivity, and dielectric properties were systematically investigated, showing that dielectric constant, as well as conductivity, had a hump at about 95 {sup o}C, which could be attributed to water molecules in the crystal boundary.

  4. Cs{sub 4}P{sub 2}Se{sub 10}: A new compound discovered with the application of solid-state and high temperature NMR

    SciTech Connect (OSTI)

    Gave, Matthew A.; Canlas, Christian G. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Chung, In [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States); Iyer, Ratnasabapathy G. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Kanatzidis, Mercouri G. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States)], E-mail: m-kanatzidis@northwestern.edu; Weliky, David P. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: weliky@chemistry.msu.edu

    2007-10-15T23:59:59.000Z

    The new compound Cs{sub 4}P{sub 2}Se{sub 10} was serendipitously produced in high purity during a high-temperature synthesis done in a nuclear magnetic resonance (NMR) spectrometer. {sup 31}P magic angle spinning (MAS) NMR of the products of the synthesis revealed that the dominant phosphorus-containing product had a chemical shift of -52.8 ppm that could not be assigned to any known compound. Deep reddish brown well-formed plate-like crystals were isolated from the NMR reaction ampoule and the structure was solved with X-ray diffraction. Cs{sub 4}P{sub 2}Se{sub 10} has the triclinic space group P-1 with a=7.3587(11) A, b=7.4546(11) A, c=10.1420(15) A, {alpha}=85.938(2){sup o}, {beta}=88.055(2){sup o}, and {gamma}=85.609(2){sup o} and contains the [P{sub 2}Se{sub 10}]{sup 4-} anion. To our knowledge, this is the first compound containing this anion that is composed of two tetrahedral (PSe{sub 4}) units connected by a diselenide linkage. It was also possible to form a glass by quenching the melt in ice water, and Cs{sub 4}P{sub 2}Se{sub 10} was recovered upon annealing. The static {sup 31}P NMR spectrum at 350 deg. C contained a single peak with a -35 ppm chemical shift and a {approx}7 ppm peak width. This study highlights the potential of solid-state and high-temperature NMR for aiding discovery of new compounds and for probing the species that exist at high temperature. - Graphical abstract: The new compound Cs{sub 4}P{sub 2}Se{sub 10} was discovered following a high-temperature in situ synthesis in the NMR spectrometer and the structure was determined by single-crystal X-ray diffraction. It contains the new [P{sub 2}Se{sub 10}]{sup 4-} anion.

  5. Vacancy-induced nanoscale phase separation in KxFe2–ySe? single crystals evidenced by Raman scattering and powder x-ray diffraction

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

    Lazarevi?, N.; Abeykoon, M.; Stephens, P. W.; Lei, Hechang; Bozin, E. S.; Petrovic, C.; Popovi?, Z. V.

    2012-08-01T23:59:59.000Z

    Polarized Raman scattering spectra of KxFe2–ySe? were analyzed in terms of peculiarities of both I4/m and I4/mmm space group symmetries. The presence of the Raman active modes from both space group symmetries (16 Raman-active modes of the I4/m phase and two Raman-active modes of the I4/mmm phase) confirmed the existence of two crystallographic domains with different space group symmetry in a KxFe2–ySe? sample. High-resolution synchrotron powder x-ray diffraction structural refinement of the same sample confirmed the two-phase description, and determined the atomic positions and occupancies for both domains.

  6. Electron-phonon superconductivity in LaO{sub 0.5}F{sub 0.5}BiSe{sub 2}

    SciTech Connect (OSTI)

    Feng, Yanqing; Du, Yongping; Wan, Xiangang, E-mail: xgwan@nju.edu.cn; Wang, Bogen [Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Ding, Hang-Chen [Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200062 (China); Savrasov, Sergey Y. [Department of Physics, University of California, Davis, One Shields Avenue, Davis, California 95616 (United States); Duan, Chun-Gang [Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200062 (China); National Laboratory for Infrared Physics, Chinese Academy of Sciences, Shanghai 200083 (China)

    2014-06-21T23:59:59.000Z

    We report density functional calculations of the electronic structure, Fermi surface, phonon spectrum and electron–phonon coupling for the newly discovered superconductor LaO{sub 0.5}F{sub 0.5}BiSe{sub 2}. It is confirmed that there is a strong Fermi surface nesting at (?,?,0), which results in unstable phonon branches. Combining the frozen phonon total energy calculations and an anharmonic oscillator model, we find that the quantum fluctuation prevents the appearance of static long–range order. The calculation shows that LaO{sub 0.5}F{sub 0.5}BiSe{sub 2} is highly anisotropic, and same as its cousin LaO{sub 0.5}F{sub 0.5}BiS{sub 2}, this compound is also a conventional electron-phonon coupling induced superconductor.

  7. Electronic Structure of the Topological Insulator Bi2Se3 Using Angle-Resolved Photoemission Spectroscopy: Evidence for a Nearly Full Surface Spin Polarization

    SciTech Connect (OSTI)

    Pan, Z.H.; Vescovo, E.; Fedorov, A.V.; Gardner, D.; Lee, Y.S.; Chu, S.; Gu, G.D.; Valla, T.

    2011-06-22T23:59:59.000Z

    We performed high-resolution spin- and angle-resolved photoemission spectroscopy studies of the electronic structure and the spin texture on the surface of Bi{sub 2}Se{sub 3}, a model TI. By tuning the photon energy, we found that the topological surface state is well separated from the bulk states in the vicinity of k{sub z} = Z plane of the bulk Brillouin zone. The spin-resolved measurements in that region indicate a very high degree of spin polarization of the surface state, {approx}0.75, much higher than previously reported. Our results demonstrate that the topological surface state on Bi{sub 2}Se{sub 3} is highly spin polarized and that the dominant factors limiting the polarization are mainly extrinsic.

  8. Measurement of the valence band-offset in a PbSe/ZnO heterojunction by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Li Lin; Qiu Jijun; Weng Binbin; Yuan Zijian; Shi Zhisheng [School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Li Xiaomin; Gan Xiaoyan [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Sellers, Ian R. [Deparment of Physics, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2012-12-24T23:59:59.000Z

    A heterojunction of PbSe/ZnO has been grown by molecular beam epitaxy. X-ray photoelectron spectroscopy was used to directly measure the valence-band offset (VBO) of the heterojunction. The VBO, {Delta}E{sub V}, was determined as 2.51 {+-} 0.05 eV using the Pb 4p{sup 3/2} and Zn 2p{sup 3/2} core levels as a reference. The conduction-band offset, {Delta}E{sub C}, was, therefore, determined to be 0.59 {+-} 0.05 eV based on the above {Delta}E{sub V} value. This analysis indicates that the PbSe/ZnO heterojunction forms a type I (Straddling Gap) heterostructure.

  9. Pressure-driven semiconductor-metal transition in intermediate-valence TmSe sub 1 minus x Te sub x and the concept of an excitonic insulator

    SciTech Connect (OSTI)

    Neuenschwander, J.; Wachter, P. (Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule Zuerich, CH-8093 Zuerich (Switzerland))

    1990-06-15T23:59:59.000Z

    This work studies the pressure-induced semiconductor-to-metal transition (SMT) in the TmSe-TmTe alloy system. This SMT is accompanied by a valence instability of the Tm ions. Single-crystalline semiconducting TmSe{sub 1{minus}{ital x}}Te{sub {ital x}} alloys are investigated under high pressure at low temperatures. Measurements of electrical resistivity, magnetic susceptibility, neutron diffraction, and optical properties are presented and discussed. A very unusual peak structure in the resistivity-pressure relation is observed at low temperatures. A discussion of the novel feature involves the concept of an excitonic insulator and {ital f}-{ital d} hybridization. The magnetic behavior of the compounds is significantly influenced by the SMT. This is thought to be mainly due to the additional coupling between the magnetic moments of Tm via free carriers which are present in the metallic state.

  10. Surface half-metallicity of CrS thin films and perfect spin filtering and spin diode effects of CrS/ZnSe heterostructure

    SciTech Connect (OSTI)

    Gao, G. Y., E-mail: guoying-gao@mail.hust.edu.cn; Yao, K. L., E-mail: klyao@mail.hust.edu.cn [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-11-03T23:59:59.000Z

    Recently, ferromagnetic zinc-blende Mn{sub 1?x}Cr{sub x}S thin films (above x?=?0.5) were fabricated experimentally on ZnSe substrate, which confirmed the previous theoretical prediction of half-metallic ferromagnetism in zinc-blende CrS. Here, we theoretically reveal that both Cr- and S-terminated (001) surfaces of the CrS thin films retain the half-metallicity. The CrS/ZnSe(001) heterogeneous junction exhibits excellent spin filtering and spin diode effects, which are explained by the calculated band structure and transmission spectra. The perfect spin transport properties indicate the potential applications of half-metallic CrS in spintronic devices. All computational results are obtained by using the density functional theory combined with nonequilibrium Green's function.

  11. Applying SE Methods Achieves Project Success to Evaluate Hammer and Fixed Cutter Grinders Using Multiple Varieties and Moistures of Biomass Feedstock for Ethanol Production

    SciTech Connect (OSTI)

    Larry R. Zirker; Christopher T. Wright, PhD; R. Douglas Hamelin

    2008-06-01T23:59:59.000Z

    Applying basic systems engineering (SE) tools to the mission analysis phases of a 2.5-million dollar biomass pre-processing project for the U.S. Department of Energy directly assisted the project principal investigator understand the complexity and identify the gaps of a moving-target project and capture the undefined technical/functional requirements and deliverables from the project team and industrial partners. A creative application of various SE tools by non-aerospace systems engineers developed an innovative “big picture” product that combined aspects of mission analysis with a project functional flow block diagram, providing immediate understanding of the depth and breath of the biomass preprocessing effort for all team members, customers, and industrial partners. The “big picture” diagram became the blue print to write the project test plan, and provided direction to bring the project back on track and achieve project success.

  12. Diffuse phase transition from the superionic to non-superionic state in Cu{sub 1.8}Se single crystal

    SciTech Connect (OSTI)

    Bikkulova, N. N.; Stepanov, Yu. M.; Bikkulova, L. V., E-mail: bickulova@mail.ru; Kurbangulov, A. R.; Kutov, A. Kh.; Karagulov, R. F. [Bashkir State University, Sterlitamak Branch (Russian Federation)

    2013-07-15T23:59:59.000Z

    The phase transition from the superionic to non-superionic state in a Cu{sub 1.8}Se single crystal is studied by neutron diffraction. In the superionic state, a diffuse halo related to the disordering of the cation subsystem is observed. It is established that the phase transition from the superionic to non-superionic state is the diffuse first-order phase transition occurring in the temperature range 250-180 K.

  13. Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2}: A new bismuth oxo-selenite bromide

    SciTech Connect (OSTI)

    Berdonosov, Peter S., E-mail: berdonosov@inorg.chem.msu.ru [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Olenev, Andrei V. [SineTheta Ltd., MSU Building 1-77, 119991 Moscow (Russian Federation)] [SineTheta Ltd., MSU Building 1-77, 119991 Moscow (Russian Federation); Kirsanova, Maria A. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation)] [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Lebed, Julia B. [Institute for nuclear research RAS, 142190, Troitsk, Moscow region (Russian Federation)] [Institute for nuclear research RAS, 142190, Troitsk, Moscow region (Russian Federation); Dolgikh, Valery A. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation)] [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation)

    2012-12-15T23:59:59.000Z

    A new bismuth oxo-selenite bromide Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2} was synthesized and structurally characterized. The crystal structure belongs to the triclinic system (space group P1-bar , Z=2, a=7.1253(7) A, b=10.972(1) A, c=12.117(1) A, {alpha}=67.765(7) Degree-Sign , {beta}=82.188(8) Degree-Sign , {gamma}=78.445(7) Degree-Sign ) and is unrelated to those of other known oxo-selenite halides. It can be considered as an open framework composed of BiO{sub x} or BiO{sub y}Br{sub z} polyhedrons forming channels running along [1 0 0] direction which contain the selenium atoms in pyramidal shape oxygen coordination (SeO{sub 3}E). The spectroscopic properties and thermal stability were studied. The new compound is stable up to 400 Degree-Sign C. - graphical abstract: New bismuth oxo-selenite bromide with new open framework structure. Highlights: Black-Right-Pointing-Pointer New bismuth oxo-selenite bromide was found and structurally characterized. Black-Right-Pointing-Pointer Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2} exhibit a new open framework structure type. Black-Right-Pointing-Pointer BiO{sub x} or BiO{sub y}Br{sub z} polyhedrons form channels in the structure which are decorated by [SeO{sub 3}E] groups.

  14. PHYSICAL REVIEW B 83, 125201 (2011) Compositional dependence of structural and electronic properties of Cu2ZnSn(S,Se)4 alloys

    E-Print Network [OSTI]

    Gong, Xingao

    2011-01-01T23:59:59.000Z

    structured Cu2ZnSnS4 (CZTS) is a promising semiconductor for low-cost and sustainable thin-film solar cell properties of Cu2ZnSn(S,Se)4 alloys for thin film solar cells Shiyou Chen,1,2 Aron Walsh,3 Ji-Hui Yang,1 X. G, Colorado 80401, USA (Received 15 December 2010; published 1 March 2011) A thin-film solar cell based on Cu2

  15. Les agricultures familiales refltent une trs grande diversit. Elles se caractrisent par une multitude de techniques, une richesse de savoir-faire et par une savante combinaison

    E-Print Network [OSTI]

    'arganiers, région de Tafraout, Maroc L'agriculture familiale ne saurait se passer de l'arbre et de la forêt. �pineux endémique du Maroc, l'arganier est parfaitement adapté à l'aridité. Les hommes ne le plantent pas mais 1998 « réserve de la biosphère » par l'Unesco. ©IRD-GenevièveMichon MAROC Les agricultures familiales

  16. Distinct Fermi Surface Topology and Nodeless Superconducting Gap in a Tl0:58Rb0:42Fe1:72Se2 Superconductor

    E-Print Network [OSTI]

    Tian, Weidong

    -based superconductors reported so far. The Fermi surface around the M point shows a nearly isotropic superconducting gap) superconductors [6]. It is important to explore whether the high-Tc superconductiv- ity mechanism in this new FeDistinct Fermi Surface Topology and Nodeless Superconducting Gap in a ðTl0:58Rb0:42�Fe1:72Se2

  17. NORMES D'ACTUACI EN CAS D'ACCIDENT 1. Els accidents hauran de justificar-se mitjanant la corresponent comunicaci

    E-Print Network [OSTI]

    Geffner, Hector

    NORMES D'ACTUACI� EN CAS D'ACCIDENT 1. Els accidents hauran de justificar-se mitjançant la corresponent comunicació d'accident que haurà d'emplenar el club, entitat esportiva o empresa prenedora a la als serveis mèdics concertats és necessari aportar la comunicació d'accident certificada i identificar

  18. Junior Master Gardener® Programs in Rural Guatemala: A Model for International Youth Development Programs

    E-Print Network [OSTI]

    Mcgucken, Anna Mae

    2014-01-13T23:59:59.000Z

    . No change in attitude toward science was observed in the student data; however, data from teachers’ surveys indicated that teachers perceived JMG lessons were important in stimulating students’ desires to learn science and in increasing students’ interests...

  19. Land Tenure and Land Administration Issues in Guatemala Danielle Kelly Donovan

    E-Print Network [OSTI]

    Onsrud, Harlan J.

    Civilization's hierarchical system and the Spanish exploitation. The Mayan Civilization involved communally by Mexico, on the southeast by Honduras and El Salvador, and on the southwest by the Pacific Ocean in 1523 lead to ruthless exploitation of Mayan land. Geography, amount and accessibility of arable land

  20. SHIFTING PERCEPTIONS OF SACRED SPACES: CEREMONIAL REUSE OF MAYA ARCHITECTURE AND MONUMENTS AT SAN BARTOLO, GUATEMALA

    E-Print Network [OSTI]

    Craig, Jessica H.

    2010-04-27T23:59:59.000Z

    is anthropology or it is nothing” (Phillips 1955; Willey and Philips 1958). Lewis Binford (1962) later took up the cause in his seminal article, “Archaeology as Anthropology.” However, Binford was ultimately not concerned with ideology and meaning. He...

  1. Results of investigations at the Zunil geothermal field, Guatemala: Well logging and brine geochemistry

    SciTech Connect (OSTI)

    Adams, A.; Dennis, B.; Van Eeckhout, E.; Goff, F.; Lawton, R.; Trujillo, P.E.; Counce, D.; Archuleta, J. (Los Alamos National Lab., NM (USA)); Medina, V. (Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico)

    1991-07-01T23:59:59.000Z

    The well logging team from Los Alamos and its counterpart from Central America were tasked to investigate the condition of four producing geothermal wells in the Zunil Geothermal Field. The information obtained would be used to help evaluate the Zunil geothermal reservoir in terms of possible additional drilling and future power plant design. The field activities focused on downhole measurements in four production wells (ZCQ-3, ZCQ-4, ZCQ-5, and ZCQ-6). The teams took measurements of the wells in both static (shut-in) and flowing conditions, using the high-temperature well logging tools developed at Los Alamos National Laboratory. Two well logging missions were conducted in the Zunil field. In October 1988 measurements were made in well ZCQ-3, ZCQ-5, and ZCQ-6. In December 1989 the second field operation logged ZCQ-4 and repeated logs in ZCQ-3. Both field operations included not only well logging but the collecting of numerous fluid samples from both thermal and nonthermal waters. 18 refs., 22 figs., 7 tabs.

  2. Experiencing Maya Palaces: Royal Power, Space, and Architecture at Holmul, Guatemala

    E-Print Network [OSTI]

    Mongelluzzo, Ryan

    2011-01-01T23:59:59.000Z

    tied with that space and the exterior panting is betterspace. The southwestern room possessed a western exteriorspace somewhat. The southern room was accessible through three exterior

  3. Unexpected victories : protecting workers' rights in Guatemala's apparel-for-export sector

    E-Print Network [OSTI]

    Connolly, Sarah E., 1977-

    2004-01-01T23:59:59.000Z

    This thesis examines three surprise victories for workers' rights in the Guatemalan garment sector. In the past three years, three unions have formed at the Choishin, Cimatextiles, and Nobland factories and each has ...

  4. Availability, prices and affordability of the World Health Organization's essential medicines for children in Guatemala

    E-Print Network [OSTI]

    Anson, Angela; Ramay, Brooke; de Esparza, Antonio; Bero, Lisa

    2012-01-01T23:59:59.000Z

    as: Anson et al. : Availability, prices and affordability ofRESEARCH Open Access Availability, prices and affordabilitywas to measure the availability, prices, and affordability

  5. Needs Assessment of Agricultural, Environmental, and Social Systems of Small Farmers in Chimaltenango, Guatemala

    E-Print Network [OSTI]

    Oleas, Carolina

    2011-02-22T23:59:59.000Z

    an ?I? was used and ?FG? for focus groups. In addition, a random number was assigned to each participant. Names with own codes were keep in a separate notebook. Data were transferred from field notes to electronic documents. In addition...

  6. Estimating the effects of new product promotion on U.S. beef in Guatemala

    E-Print Network [OSTI]

    Leister, Amanda Marie

    2009-06-02T23:59:59.000Z

    for Central America that the most effective way to launch the new beef products was to focus on one specific importer of U.S. meat. The firm Alimentos Campe?n was identified as the key HRI supplier to support the promotion. Marketing activities included... February, 2007 are provided by Alimentos Campe?n. The study is restricted to the changes in U.S. beef value cut quantity sold by Alimentos Campe?n as a response to prices and the new product promotion activities conducted. The endogenous variable...

  7. Frictional characteristics of serpentinite from the Motagua fault zone in Guatemala: an experimental study 

    E-Print Network [OSTI]

    Dengo, Carlos Arturo

    1978-01-01T23:59:59.000Z

    of the requirement for the degree of MASTER OF SCIENCE December 1978 Mad or Subjec' . " Geology FRICTIONAL CHARACTERISTIC OF SERPENTINITF. FRON THE I", OTAGUA FAULT ZONE Ili GUATENALA: AN EXPERIMENTAL STUDY A Thesis by CARLOS ARTURO DFNGO App", oved... strike-slip, seismogenic faults warrants a systematic i nvesti ga tion to determine ho v it". frictional characteristics may afreet slip along the fault. Five locations aiong the fault zone were sampled to investigate the sliding !rode as a function...

  8. A Study of Sustainable Compost Micro-Enterprise In Chimaltenango, Guatemala: Profitability and Employee Characteristics

    E-Print Network [OSTI]

    Silberg, Timothy

    2012-02-14T23:59:59.000Z

    , Pagiola, & Raiche, 1994). Lutz et al. (1994) explain ed that land degradation poses a severe threat to the sustainability of agricultural production. Soil degradation, ??is common in de?eloping countries. A history of Mayan agricultural practices has... ) - the measured amount of factor input per unit of gross output; the labor and capital requirements embodied in the commodity; the input requirements per unit of commodity, directly or indirectly through the production of the commodity inputs. A measureme nt...

  9. An evaluation of the geothermal potential of the Tecuamburro Volcano area of Guatemala

    SciTech Connect (OSTI)

    Heiken, G.; Duffield, W. (eds.)

    1990-09-01T23:59:59.000Z

    Radiometric ages indicate that the Tecuamburro Volcano and three adjacent lava domes grew during the last 38,300 years, and that a 360-m-wide phreatic crater, Laguna Ixpaco, was formed near the base of these domes about 2900 years ago. Laguna Ixpaco is located within the Chupadero crater, from which pyroxene pumice deposits were erupted 38,300 years ago. Thus, the likelihood is great for a partly molten or solid-but-still-hot near-surface intrusion beneath the area. Fumaroles and hot springs issue locally from the Tecuamburro volcanic complex and near Laguna Ixpaco. Analyses of gas and fluid samples from these and other nearby thermal manifestations yield chemical-geothermometer temperatures of about 150{degree} to 300{degree}C, with the highest temperatures at Ixpaco. The existence of a commercial-grade geothermal reservoir beneath the Ixpaco area seems likely. 84 refs., 70 figs., 12 tabs.

  10. ReadyMade Analysis of Hospital de la Familia’s Cataract Surgery Program in Guatemala

    E-Print Network [OSTI]

    Brown, Clair; Freeman, Eric; Belohlav, Kate; Chait, Ariel; Thal, Lawrence

    2012-01-01T23:59:59.000Z

    Center for Work, Technology, and Society, IRLE University ofCenter for Work, Technology, and Society, UC Berkeley, to

  11. Guatemala-Low-Carbon Energy for Central America: Building a Regional Model

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI ReferenceJumpEnergy InformationGrupo Urbas(EC-LEDS) || Open

  12. Surface and substrate induced effects on thin films of the topological insulators Bi2Se3 and Bi2Te3

    SciTech Connect (OSTI)

    Liu, Wenliang [Xiangtan University, Xiangtan Hunan, China; Peng, Xiangyang [Xiangtan University, Xiangtan Hunan, China; Wei, Xiaolin [Xiangtan University, Xiangtan Hunan, China; Yang, Hong [Xiangtan University, Xiangtan Hunan, China; Stocks, George Malcolm [ORNL; Zhong, Jianxin [Xiangtan University, Xiangtan Hunan, China

    2013-01-01T23:59:59.000Z

    Based on van der Waals density functional calculations, we have studied few-quintuple-layer (QL) films of Bi2Se3 and Bi2Te3. The separation between the QLs near the surface is found to have a large increase after relaxation, whereas, the separation between the inner QLs is smaller and approaches the bulk value as the thickness grows, showing a two-dimensional to three-dimensional structural crossover. Accordingly, the surface Dirac cone of the Bi2Se3 film is evidently gapped for small thicknesses (two to four QLs), and the gap is reduced and, finally, is closed with the increasing thickness, agreeing well with the experiments. We further studied the substrate effect by investigating the Bi2Se3/graphene system. It is found that the underlying graphene induces a giant thickness-dependent Rashba splitting and Dirac point shift. Because Bi2Te3 films have smaller relative inter-QL expansion and stronger spin-orbit coupling, the topological features start to appear in the film as thin as two QLs in good accord with the experiments.

  13. Target: Subpoena (2010-SE-2001)

    Broader source: Energy.gov [DOE]

    DOE issued a Subpoena for Information and Production of Documents to Target Corporation requesting information regarding the compliance of various torchieres Target has distributed in commerce in the U.S.

  14. 4, 667695, 2008 SE Atlantic

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Research Centre, Department of Geography, University College London, Pearson Building, Gower Street, London, WC1E 6BT, UK 2 NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham Discussion Abstract A detailed record of benthic foraminifera carbon isotopes from the South East Atlantic

  15. ar Career Se ummarizes th

    E-Print Network [OSTI]

    Plotkin, Joshua B.

    nt prior to gra e), technology s $61,401, w nearly 68% a 9. We saw a hool, seeking graduate sc yne aduation. The y, consulting which was a s accepted posi 6% increase g graduate sc chool, 64.9% Associate to the Engineering section of the Career Services website for any student in the Class of 2010 who was browsing

  16. News-PHaSe-EFRC

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

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  17. Publications-PHaSe-EFRC

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

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  18. Research-PHaSe-EFRC

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Press ReleasesIn the Inorganic PVResearch The

  19. Resources-PHaSe-EFRC

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Press ReleasesIn the InorganicResourcesResources

  20. Solon SE | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk, NewSingapore JumpSolarezoSolicore IncSoloPower Jump

  1. About-PHaSe-EFRC

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMForms About Become agovEducationWelcome toAboutAboutUsUserAbout

  2. Ballistic performance comparison of monolayer transition metal dichalcogenide MX{sub 2} (M = Mo, W; X = S, Se, Te) metal-oxide-semiconductor field effect transistors

    SciTech Connect (OSTI)

    Chang, Jiwon; Register, Leonard F.; Banerjee, Sanjay K. [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

    2014-02-28T23:59:59.000Z

    We study the transport properties of monolayer MX{sub 2} (M?=?Mo, W; X?=?S, Se, Te) n- and p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) using full-band ballistic non-equilibrium Green's function simulations with an atomistic tight-binding Hamiltonian with hopping potentials obtained from density functional theory. We discuss the subthreshold slope, drain-induced barrier lowering (DIBL), as well as gate-induced drain leakage (GIDL) for different monolayer MX{sub 2} MOSFETs. We also report the possibility of negative differential resistance behavior in the output characteristics of nanoscale monolayer MX{sub 2} MOSFETs.

  3. Photoconductivity of structures based on the SnO{sub 2} porous matrix coupled with core-shell CdSe/CdS quantum dots

    SciTech Connect (OSTI)

    Drozdov, K. A.; Kochnev, V. I.; Dobrovolsky, A. A.; Khokhlov, D. R. [Department of Physics, Moscow State University, 119991 Moscow (Russian Federation)] [Department of Physics, Moscow State University, 119991 Moscow (Russian Federation); Popelo, A. V. [Department of Materials Science, Moscow State University, 119991 Moscow (Russian Federation)] [Department of Materials Science, Moscow State University, 119991 Moscow (Russian Federation); Rumyantseva, M. N.; Gaskov, A. M.; Ryabova, L. I. [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation)] [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Vasiliev, R. B. [Department of Materials Science, Moscow State University, 119991 Moscow (Russian Federation) [Department of Materials Science, Moscow State University, 119991 Moscow (Russian Federation); Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation)

    2013-09-23T23:59:59.000Z

    Embedding of quantum dots into porous oxide matrixes is a perspective technique for photosensitization of a structure. We show that the sensitization efficiency may be increased by the use of core-shell quantum dots. It is demonstrated that the photoresponse amplitude in a SnO{sub 2} porous matrix with CdSe/CdS quantum dots depends non-monotonously on the number of atomic layers in a shell. The best results are obtained for SnO{sub 2} matrixes coupled with the quantum dots with three atomic layers of a shell. Mechanisms responsible for the structure sensitization are discussed.

  4. Indium-Gallium Segregation in CuIn$_{x}$Ga$_{1-x}$Se$_2$: An ab initio based Monte Carlo Study

    E-Print Network [OSTI]

    Ludwig, Christian D R; Felser, Claudia; Schilling, Tanja; Windeln, Johannes; Kratzer, Peter

    2010-01-01T23:59:59.000Z

    Thin-film solar cells with CuIn$_x$Ga$_{1-x}$Se$_2$ (CIGS) absorber are still far below their efficiency limit, although lab cells reach already 19.9%. One important aspect is the homogeneity of the alloy. Large-scale simulations combining Monte Carlo and density functional calculations show that two phases coexist in thermal equilibrium below room temperature. Only at higher temperatures, CIGS becomes more and more a homogeneous alloy. A larger degree of inhomogeneity for Ga-rich CIGS persists over a wide temperature range, which may contribute to the low observed efficiency of Ga-rich CIGS solar cells.

  5. Geochemistry of V and NI in bitumen and the depositional environment of the Meade Peak phosphatic shale member of the Phosphoria formation in SE Idaho

    SciTech Connect (OSTI)

    Sharata, S.M. (Univ. of Idaho, Moscow (USA)); Filby, R.H. (Washington State Univ., Pullman (USA))

    1989-03-01T23:59:59.000Z

    Stratigraphic and geographic variation in V and Ni abundances and the (V/Ni + V) ration in bitumens from phosphorite and shale of the Meade Peak Member of SE Idaho reflect systematic vertical and lateral changes in environmental conditions during deposition of these rocks. These variations may have been preserved during generation, migration and accumulation of the Phosphoria oil. Thus, V/(Ni + V) ratios are useful geochemical parameters in reconstruction of the depositional environment, discrimination of genetic oil-types, and correlation of oil-source rock of the Phosphoria in the northern Rocky Mountains region.

  6. Electronic Instability in a Zero-Gap Semiconductor: The Charge-Density Wave in (TaSe4)2I

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

    Tournier-Colletta, C.; Moreschini, L.; Autès, G.; Moser, S.; Crepaldi, A.; Berger, H.; Walter, A. L.; Kim, K. S.; Bostwick, A.; Monceau, P.; Rotenberg, E.; Yazyev, O. V.; Grioni, M.

    2013-06-01T23:59:59.000Z

    We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)2I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below TCDW=263??K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at TCDW.

  7. Midea: Proposed Penalty (2010-SE-0110, 2012-SE-1402, 2012-SE...

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

    Notice of Proposed Civil Penalty that Midea America Corp., Hefei Hualing Co., Ltd., and China Refrigeration Industry Co., Ltd. manufactured and distributed noncompliant...

  8. Impact of environmental conditions on the chemical surface properties of Cu(In,Ga)(S,Se){sub 2} thin-film solar cell absorbers

    SciTech Connect (OSTI)

    Hauschild, D., E-mail: dirk.hauschild@physik.uni-wuerzburg.de, E-mail: l.weinhardt@kit.edu; Meyer, F. [Experimental Physics VII, University of Würzburg, Am Hubland, 97074 Würzburg (Germany); Pohlner, S.; Lechner, R.; Dietmüller, R.; Palm, J. [AVANCIS GmbH and Co. KG, Otto-Hahn-Ring 6, 81739 Munich (Germany); Heske, C. [Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Las Vegas, Nevada 89154-4003 (United States); Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 18/20, 76128 Karlsruhe (Germany); Weinhardt, L., E-mail: dirk.hauschild@physik.uni-wuerzburg.de, E-mail: l.weinhardt@kit.edu [Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Las Vegas, Nevada 89154-4003 (United States); Reinert, F. [Experimental Physics VII, University of Würzburg, Am Hubland, 97074 Würzburg (Germany); Karlsruhe Institute of Technology (KIT), Gemeinschaftslabor für Nanoanalytik, 76021 Karlsruhe (Germany)

    2014-05-14T23:59:59.000Z

    Environmentally driven aging effects play a crucial role in thin-film solar cells based on Cu(In,Ga)(S,Se){sub 2}, both for long-term stability and short air exposure during production. For a better understanding of such effects, Cu(In,Ga)(S,Se){sub 2} absorber surfaces were investigated by x-ray photoelectron and Auger electron spectroscopy after exposure to different environmental conditions. Identical absorbers were stored in a nitrogen atmosphere, in damp heat, and under ambient conditions for up to 14 days. We find varying degrees of diffusion of sulfur, copper, and sodium towards the surface, with potential impact on the electronic surface structure (band gap) and the properties of the interface to a buffer layer in a solar cell device. Furthermore, we observe an oxidation (in decreasing order) of indium, copper, and selenium (but no oxidation of sulfur). And finally, varying amounts of carbon- and oxygen-containing adsorbates are found. In particular, the findings suggest that, for ambient air exposure, sodium carbonate is formed at the surface.

  9. Reaction rates of $^{64}$Ge($p,?$)$^{65}$As and $^{65}$As($p,?$)$^{66}$Se and the extent of nucleosynthesis in type I X-ray bursts

    E-Print Network [OSTI]

    Y. H. Lam; J. J. He; A. Parikh; B. A. Brown; M. Wang; B. Guo; Y. H. Zhang; X. H. Zhou; H. S. Xu

    2015-05-09T23:59:59.000Z

    The extent of nucleosynthesis in models of type I X-ray bursts and the associated impact on the energy released in these explosive events are sensitive to nuclear masses and reaction rates around the $^{64}$Ge waiting point. Using a recent high precision mass measurement of $^{65}$As along with large-scale shell model calculations, we have determined new thermonuclear rates of the $^{64}$Ge($p$,$\\gamma$)$^{65}$As and $^{65}$As($p$,$\\gamma$)$^{66}$Se reactions. We examine the impact of available rates for these two reactions through a representative one-zone X-ray burst model. We find that our recommended rates may strongly suppress the flow of abundances toward $A\\approx100$, in sharp contrast to recent work claiming that $^{64}$Ge is not a significant $rp$-process waiting point. Indeed, the summed mass fractions for species with $A > 70$ varies by about factors of 3 or 2 depending upon the adopted $^{64}$Ge($p$,$\\gamma$)$^{65}$As or $^{65}$As($p$,$\\gamma$)$^{66}$Se rates, respectively. Furthermore, the predictions for nuclear energy generation rate E$_\\mathrm{gen}$ at late times during the burst varies rather significantly between the models using the different rates, with differences as large as about a factor of 2.

  10. Enhancement of transition temperature in Fe{sub x}Se{sub 0.5}Te{sub 0.5} film via iron vacancies

    SciTech Connect (OSTI)

    Zhuang, J. C. [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China); Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia); Yeoh, W. K., E-mail: waikong.yeoh@sydney.edu.au, E-mail: zxshi@seu.edu.cn [Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia); Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006 (Australia); School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006 (Australia); Cui, X. Y.; Ringer, S. P. [Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006 (Australia); School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006 (Australia); Kim, J. H.; Shi, D. Q.; Wang, X. L.; Dou, S. X. [Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia); Shi, Z. X., E-mail: waikong.yeoh@sydney.edu.au, E-mail: zxshi@seu.edu.cn [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China)

    2014-06-30T23:59:59.000Z

    The effects of iron deficiency in Fe{sub x}Se{sub 0.5}Te{sub 0.5} thin films (0.8???x???1) on superconductivity and electronic properties have been studied. A significant enhancement of the superconducting transition temperature (T{sub C}) up to 21?K was observed in the most Fe deficient film (x?=?0.8). Based on the observed and simulated structural variation results, there is a high possibility that Fe vacancies can be formed in the Fe{sub x}Se{sub 0.5}Te{sub 0.5} films. The enhancement of T{sub C} shows a strong relationship with the lattice strain effect induced by Fe vacancies. Importantly, the presence of Fe vacancies alters the charge carrier population by introducing electron charge carriers, with the Fe deficient film showing more metallic behavior than the defect-free film. Our study provides a means to enhance the superconductivity and tune the charge carriers via Fe vacancy, with no reliance on chemical doping.

  11. Ultra-broadband terahertz time-domain ellipsometric spectroscopy utilizing GaP and GaSe emitters and an epitaxial layer transferred photoconductive detector

    SciTech Connect (OSTI)

    Yamashita, Masatsugu, E-mail: m-yama@riken.jp; Takahashi, Hideki; Otani, Chiko [RIKEN Center for Advanced Photonics, 519-1399 Aobaaramaki, Aoba-ku, Sendai 980-0845 (Japan); Ouchi, Toshihiko [Corporate R and D Headquarters, Canon Inc., 30-2 Shimomaruko 3-Chome, Ohta-ku, Tokyo 145-8501 (Japan)

    2014-02-03T23:59:59.000Z

    We present a reflection-type ultra-broadband terahertz (THz) time-domain spectroscopic ellipsometry system covering the frequency range of 0.5–30 THz. GaP (110) and z-cut GaSe crystals are used as emitters to generate the THz and mid-infrared pulses, respectively, and a photoconductive antenna switch using a low-temperature grown GaAs epitaxial layer transferred on Si substrate was used as a detector. By changing the emitter between the GaP and GaSe crystals, the measurable frequency range can be easily switched from the 0.5–7.8 THz range to the 7.8–30 THz range without additional optical alignment. We demonstrated the measurement of the dielectric function in a p-type InAs wafer and the optical conductivity of an indium tin oxide (ITO) thin film. The obtained carrier density and the mobility of the ITO thin film show good agreement with that obtained by the Hall measurement.

  12. Fabrication and testing of diamond-machined gratings in ZnSe, GaP, and bismuth germanate for the near infrared and visible

    SciTech Connect (OSTI)

    Kuzmenko, P J; Little, S L; Ikeda, Y; Kobayashi, N

    2008-06-22T23:59:59.000Z

    High quality immersion gratings for infrared applications have been demonstrated in silicon and germanium. To extend this technology to shorter wavelengths other materials must be investigated. We selected three materials, zinc selenide, gallium phosphide and bismuth germanate (Bi{sub 4}Ge{sub 3}O{sub 12}), based on high refractive index, good visible transmission and commercial availability in useful sizes. Crystal samples were diamond turned on an ultra-precision lathe to identify preferred cutting directions. Using this information we diamond-flycut test gratings over a range of feed rates to determine the optimal cutting conditions. For both ZnSe and GaP good surface quality was achieved at feed rates up to 1.0 cm/minute using a special compound angle diamond tool with negative rake angles on both cutting surfaces. The surface roughness of the groove facets was about 4 nm. A Zygo interferometer measured grating wavefront errors in reflection. For the ZnSe the RMS error was < {lambda}/20 at 633nm. More extensive testing was performed with a HeNe laser source and a cooled CCD camera. These measurements demonstrated high relative diffraction efficiency (> 80%), low random groove error (2.0 nm rms), and Rowland ghost intensities at < 0.1%. Preliminary tests on bismuth germanate show high tool wear.

  13. The synthesis and crystal structures of the first rare-earth alkaline-earth selenite chlorides MNd{sub 10}(SeO{sub 3}){sub 12}Cl{sub 8} (M=Ca and Sr)

    SciTech Connect (OSTI)

    Berdonosov, P.S. [Department of Chemistry, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation)], E-mail: psberd@inorg.chem.msu.ru; Olenev, A.V.; Dolgikh, V.A. [Department of Chemistry, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Lightfoot, P. [EaStChem, School of Chemistry, St. Andrews University, St. Andrews, KY16 9ST (United Kingdom)

    2007-11-15T23:59:59.000Z

    Two new alkaline-earth Nd selenite chlorides MNd{sub 10}(SeO{sub 3}){sub 12}Cl{sub 8} (M=Ca, Sr) were obtained using crystal growth from alkaline-earth chloride melts in quartz tubes. These new compounds crystallize in the orthorhombic system in space group C cca (no. 68). The compounds were studied by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. It was shown that both compounds adopt the same structure type, constructed by complex [M{sub 11}(SeO{sub 3}){sub 12}]{sup 8+} slabs separated by chloride anion layers perpendicular to the longest cell parameter. The SeO{sub 3} groups show a pyramidal shape and may be described as SeO{sub 3}E tetrahedra. Such SeO{sub 3} groups decorate the Nd-O skeletons forming the [M{sub 11}(SeO{sub 3}){sub 12}]{sup 8+} slabs. - Graphical abstract: Two new alkaline-earth Nd selenite chlorides MNd{sub 10}(SeO{sub 3}){sub 12}Cl{sub 8} (M=Ca, Sr) were synthesized. These structures are constructed by [M{sub 11}(SeO{sub 3}){sub 12}]{sup 8+} slabs separated by chloride anion layers.

  14. Il Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi" of-fre la possibilit a giovani ricercatori di svolgere la loro a vit in se ori

    E-Print Network [OSTI]

    'uomo e all'energia. Nel se ore dell'energia il Centro Fermi ha dedicato uno dei propri proge strategici basano sul concentratore solare sviluppato u lizzando tecnologie mature derivan dal se ore automobili &ENERGIA Attività editoriale a cura de Il Sole 24 ORE Business Media LO SCENARIO / I risultati del rapporto

  15. Effect of carrier recombination on ultrafast carrier dynamics in thin films of the topological insulator Bi{sub 2}Se{sub 3}

    SciTech Connect (OSTI)

    Glinka, Yuri D., E-mail: ydglinka@mail.wvu.edu [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Institute of Physics, National Academy of Sciences of Ukraine, Kiev 03028 (Ukraine); Babakiray, Sercan; Johnson, Trent A.; Holcomb, Mikel B.; Lederman, David [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

    2014-10-27T23:59:59.000Z

    Transient reflectivity (TR) from thin films (6–40?nm thick) of the topological insulator Bi{sub 2}Se{sub 3} revealed ultrafast carrier dynamics, which suggest the existence of both radiative and non-radiative recombination between electrons residing in the upper cone of initially unoccupied high energy Dirac surface states (SS) and holes residing in the lower cone of occupied low energy Dirac SS. The modeling of measured TR traces allowed us to conclude that recombination is induced by the depletion of bulk electrons in films below ?20?nm thick due to the charge captured on the surface defects. We predict that such recombination processes can be observed using time-resolved photoluminescence techniques.

  16. Research on high efficiency, large-area CuInSe{sub 2}-based thin-film modules. Annual subcontract report, 1 May 1991--30 April 1992

    SciTech Connect (OSTI)

    Mitchell, K.W.; Eberspacher, C. [Siemens Solar Industries, Camarillo, CA (United States)

    1993-02-01T23:59:59.000Z

    Objective was to demonstrate 12.5% aperture efficient, large area (3900 cm{sup 2}) encapsulated thin thin CuInSe{sub 2} (CIS) modules. The module design consists of 53 series-connected ZnO/CdS/CIS/Mo/glass cells fabricated on a glass substrate. A baseline characterization of the CIS modules was established during Phase 1. Maps of open circuit voltage provide information on junction quality uniformity. Maps of cell voltages at fixed forward bias show variations in resistance losses due to interconnects. Individual cell I-V curves can be evaluated. Physical nature of defects is correlated using OBIC, EBIC, SEM, tape adhesion, etc. A new world record of 37.7 W and 9.7% aperture efficiency was attained for an encapsulated module; an unencapsulated CIS module plate achieved 40.8 W and 10.5% aperture efficiency.

  17. Transmission measurement at 10.6 microns of Te2As3Se5 rib-waveguides on As2S3 substrate

    E-Print Network [OSTI]

    Vigreux-Bercovici, C; Pradel, A; Broquin, J -E; Labadie, L; Kern, P

    2007-01-01T23:59:59.000Z

    The feasibility of chalcogenide rib waveguides working at lambda = 10.6 microns has been demonstrated. The waveguides comprised a several microns thick Te2As3Se5 film deposited by thermal evaporation on a polished As2S3 glass substrate and further etched by physical etching in Ar or CF4/O2 atmosphere. Output images at 10.6 microns and some propagation losses roughly estimated at 10dB/cm proved that the obtained structures behaved as channel waveguides with a good lateral confinement of the light. The work opens the doors to the realisation of components able to work in the mid and thermal infrared up to 20 microns and even more.

  18. Synthesis of CdS/CdSe core/shell ultra small nanostructures using new microwave assisted ultrasonic sol gel route

    SciTech Connect (OSTI)

    Goswami, Y. C., E-mail: y-goswami@yahoo.com; Kumar, Vijay, E-mail: y-goswami@yahoo.com [School of Physical Sciences, ITM University, Sithouli, Gwalior- 474001 (India); Sharma, Ranjana [Institute of Technology and Management, Sithouli, Gwalior- 474001 (India); Singh, Rajeev [Institute of Information Technology and Management, Sithouli, Gwalior, MP 474001 (India)

    2014-04-24T23:59:59.000Z

    Core-shell CdS/CdSe nanostructures have been synthesized by new microwave assisted ultrasonic sol gel route. The solution was obtained by dissolving cadmium acetate and Thiourea in the molar ratio 1:1 in Triethlioamine. The solution was Ultrasonically irradiated by Ultrasonic crystal at 40 Hz for 3 hours at 70°C. The sol was kept for another 24 hours for gel formation. Selenium dioxide was used as a selenium source and added separately. The gel was spin coated on Quartz and Glass slides followed by microwave heat treatment. The samples were characterized by structural morphological and optical characterization. XRD studies confirm the zinc blende phase of the CdS nanoparticles. The mean nanocrystal sizes calculated using Scherrer equation is ?1.2nm. Optical studies show the strong blue shift in the spectra due to very small size of the nanocrystals. TEM and HRTEM confirm the formation of core shell structures.

  19. Substitution of Ni for Fe in superconducting Fe?.??Te?.?Se?.? depresses the normal-state conductivity but not the magnetic spectral weight

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

    Wang, Jinghui; Tranquada, J. M.; Zhong, Ruidan; Li, Shichao; Gan, Yuan; Xu, Zhijun; Zhang, Cheng; Ozaki, T.; Matsuda, M.; Zhao, Yang; et al

    2015-01-01T23:59:59.000Z

    We have performed systematic resistivity and inelastic neutron scattering measurements on Fe?.???zNizTe?.?Se?.? samples to study the impact of Ni substitution on the transport properties and the low-energy (? 12 meV) magnetic excitations. It is found that, with increasing Ni doping, both the conductivity and superconductivity are gradually suppressed; in contrast, the low-energy magnetic spectral weight changes little. Comparing with the impact of Co and Cu substitution, we find that the effects on conductivity and superconductivity for the same degree of substitution grow systematically as the atomic number of the substituent deviates from that of Fe. The impact of the substituentsmore »as scattering centers appears to be greater than any contribution to carrier concentration. The fact that low-energy magnetic spectral weight is not reduced by increased electron scattering indicates that the existence of antiferromagnetic correlations does not depend on electronic states close to the Fermi energy.« less

  20. Anomalous reduction of the switching voltage of Bi-doped Ge{sub 0.5}Se{sub 0.5} ovonic threshold switching devices

    SciTech Connect (OSTI)

    Seo, Juhee [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Ahn, Hyung-Woo [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Material Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Shin, Sang-yeol [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Cheong, Byung-ki; Lee, Suyoun, E-mail: slee-eels@kist.re.kr [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2014-04-14T23:59:59.000Z

    Switching devices based on Ovonic Threshold Switching (OTS) have been considered as a solution to overcoming limitations of Si-based electronic devices, but the reduction of switching voltage is a major challenge. Here, we investigated the effect of Bi-doping in Ge{sub 0.5}Se{sub 0.5} thin films on their thermal, optical, electrical properties, as well as on the characteristics of OTS devices. As Bi increased, it was found that both of the optical energy gap (E{sub g}{sup opt}) and the depth of trap states decreased resulting in a drastic reduction of the threshold voltage (V{sub th}) by over 50%. In addition, E{sub g}{sup opt} was found to be about three times of the conduction activation energy for each composition. These results are explained in terms of the Mott delocalization effect by doping Bi.

  1. Substitution of Ni for Fe in superconducting Fe?.??Te?.?Se?.? depresses the normal-state conductivity but not the magnetic spectral weight

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

    Wang, Jinghui [Nanjing Univ., Nanjing (China); Tranquada, J. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhong, Ruidan [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Li, Shichao [Nanjing Univ., Nanjing (China); Gan, Yuan [Nanjing Univ., Nanjing (China); Xu, Zhijun [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhang, Cheng [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Ozaki, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Matsuda, M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhao, Yang [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States); Li, Qiang [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Birgeneau, R. J. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wen, Jinsheng [Nanjing Univ., Nanjing (China)

    2015-01-01T23:59:59.000Z

    We have performed systematic resistivity and inelastic neutron scattering measurements on Fe?.???zNizTe?.?Se?.? samples to study the impact of Ni substitution on the transport properties and the low-energy (? 12 meV) magnetic excitations. It is found that, with increasing Ni doping, both the conductivity and superconductivity are gradually suppressed; in contrast, the low-energy magnetic spectral weight changes little. Comparing with the impact of Co and Cu substitution, we find that the effects on conductivity and superconductivity for the same degree of substitution grow systematically as the atomic number of the substituent deviates from that of Fe. The impact of the substituents as scattering centers appears to be greater than any contribution to carrier concentration. The fact that low-energy magnetic spectral weight is not reduced by increased electron scattering indicates that the existence of antiferromagnetic correlations does not depend on electronic states close to the Fermi energy.

  2. Substitution of Ni for Fe in superconducting Fe?.??Te?.?Se?.? depresses the normal-state conductivity but not the magnetic spectral weight

    SciTech Connect (OSTI)

    Wang, Jinghui [Nanjing Univ., Nanjing (China); Tranquada, J. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhong, Ruidan [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Li, Shichao [Nanjing Univ., Nanjing (China); Gan, Yuan [Nanjing Univ., Nanjing (China); Xu, Zhijun [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhang, Cheng [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Ozaki, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Matsuda, M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhao, Yang [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States); Li, Qiang [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Birgeneau, R. J. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wen, Jinsheng [Nanjing Univ., Nanjing (China)

    2015-01-01T23:59:59.000Z

    We have performed systematic resistivity and inelastic neutron scattering measurements on Fe?.???zNizTe?.?Se?.? samples to study the impact of Ni substitution on the transport properties and the low-energy (? 12 meV) magnetic excitations. It is found that, with increasing Ni doping, both the conductivity and superconductivity are gradually suppressed; in contrast, the low-energy magnetic spectral weight changes little. Comparing with the impact of Co and Cu substitution, we find that the effects on conductivity and superconductivity for the same degree of substitution grow systematically as the atomic number of the substituent deviates from that of Fe. The impact of the substituents as scattering centers appears to be greater than any contribution to carrier concentration. The fact that low-energy magnetic spectral weight is not reduced by increased electron scattering indicates that the existence of antiferromagnetic correlations does not depend on electronic states close to the Fermi energy.

  3. Research on polycrystalline thin-film CuGaInSe{sub 2} solar cells. Annual subcontract report, 3 May 1991--2 May 1992

    SciTech Connect (OSTI)

    Stanbery, B.J.; Chen, W.S.; Devaney, W.E.; Stewart, J.W. [Boeing Co., Seattle, WA (United States). Defense and Space Systems Group

    1992-11-01T23:59:59.000Z

    This report describes research to fabricate high-efficiency CdZnS/CuInGaSe{sub 2} (CIGS) thin-film solar cells, and to develop improved transparent conductor window layers such as ZnO. A specific technical milestone was the demonstration of an air mass (AM) 1.5 global, 13% efficient, 1-cm{sup 2}-total-area CIGS thin-film solar cell. Our activities focused on three areas. First, a CIGS deposition: system was modified to double its substrate capacity, thus increasing throughput, which is critical to speeding the process development by providing multiple substrates from the same CIGS run. Second, new tooling was developed to enable an investigation of a modified aqueous CdZnS process. The goal was to improve the yield of this critical step in the device fabrication process. Third, our ZnO sputtering system was upgraded to improve its reliability, and the sputtering parameters were further optimized to improve its properties as a transparent conducting oxide. The characterization of the new CIGS deposition system substrate fixturing was completed, and we produced good thermal uniformity and adequately high temperatures for device-quality CIGS deposition. Both the CIGS and ZnO deposition processes were refined to yield a ZnO//Cd{sub 0.82}Zn{sub 0.18}S/CuIn{sub 0.80}Ga{sub 0.20}Se{sub 2} cell that was verified at NREL under standard testing conditions at 13.1% efficiency with V{sub oc} = 0.581 V, J{sub sc} = 34.8 mA/cm{sup 2}, FF = 0.728, and a cell area of 0.979 cm{sup 2}.

  4. VOLUME 88, NUMBER 4 P H Y S I C A L R E V I E W L E T T E R S 28 JANUARY 2002 Electronic Structure of Glassy Chalcogenides As4Se4 and As2Se3

    E-Print Network [OSTI]

    Drabold, David

    , dynamics, and electronic structure of these glasses. Krecmer et al. [2] demonstrated an opto- mechanical possible. In this Letter, we present a calculation of the electronic structure of models of g-As4Se4 usingVOLUME 88, NUMBER 4 P H Y S I C A L R E V I E W L E T T E R S 28 JANUARY 2002 Electronic Structure

  5. Effect of burst and recombination models for Monte Carlo transport of interacting carriers in a-Se x-ray detectors on Swank noise

    SciTech Connect (OSTI)

    Fang, Yuan, E-mail: yuan.fang@fda.hhs.gov [Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993-0002 and Department of Electrical and Computer Engineering, The University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)] [Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993-0002 and Department of Electrical and Computer Engineering, The University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Karim, Karim S. [Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)] [Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Badano, Aldo [Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993-0002 (United States)] [Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993-0002 (United States)

    2014-01-15T23:59:59.000Z

    Purpose: The authors describe the modification to a previously developed Monte Carlo model of semiconductor direct x-ray detector required for studying the effect of burst and recombination algorithms on detector performance. This work provides insight into the effect of different charge generation models for a-Se detectors on Swank noise and recombination fraction. Methods: The proposed burst and recombination models are implemented in the Monte Carlo simulation package, ARTEMIS, developed byFang et al. [“Spatiotemporal Monte Carlo transport methods in x-ray semiconductor detectors: Application to pulse-height spectroscopy in a-Se,” Med. Phys. 39(1), 308–319 (2012)]. The burst model generates a cloud of electron-hole pairs based on electron velocity, energy deposition, and material parameters distributed within a spherical uniform volume (SUV) or on a spherical surface area (SSA). A simple first-hit (FH) and a more detailed but computationally expensive nearest-neighbor (NN) recombination algorithms are also described and compared. Results: Simulated recombination fractions for a single electron-hole pair show good agreement with Onsager model for a wide range of electric field, thermalization distance, and temperature. The recombination fraction and Swank noise exhibit a dependence on the burst model for generation of many electron-hole pairs from a single x ray. The Swank noise decreased for the SSA compared to the SUV model at 4 V/?m, while the recombination fraction decreased for SSA compared to the SUV model at 30 V/?m. The NN and FH recombination results were comparable. Conclusions: Results obtained with the ARTEMIS Monte Carlo transport model incorporating drift and diffusion are validated with the Onsager model for a single electron-hole pair as a function of electric field, thermalization distance, and temperature. For x-ray interactions, the authors demonstrate that the choice of burst model can affect the simulation results for the generation of many electron-hole pairs. The SSA model is more sensitive to the effect of electric field compared to the SUV model and that the NN and FH recombination algorithms did not significantly affect simulation results.

  6. Compared Raman study of the phase transitions in K2ZnCl4 and Rb2ZnCl4, Rb2ZnBr4, K2SeO4

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    787 Compared Raman study of the phase transitions in K2ZnCl4 and Rb2ZnCl4, Rb2ZnBr4, K2SeO4 M to the incommensurate phase is discussed for the four compounds K2SeO4, K2ZnCl4, Rb2ZnCl4 and Rb2ZnBr4 on the basis measurements on K2ZnC'4 known to exhibit successive phase transitions similar to those of K2SeO4

  7. Cu(In,Ga)Se{sub 2} absorber thinning and the homo-interface model: Influence of Mo back contact and 3-stage process on device characteristics

    SciTech Connect (OSTI)

    Leonard, E.; Arzel, L.; Tomassini, M.; Barreau, N., E-mail: nicolas.barreau@univ-nantes.fr [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Zabierowski, P. [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, PL 00-662 Warsaw (Poland); Fuertes Marrón, D. [Instituto de Energía Solar–ETSIT, Technical University of Madrid, Ciudad Universitaria s.n., 28040 Madrid (Spain)

    2014-08-21T23:59:59.000Z

    Thinning the absorber layer is one of the possibilities envisaged to further decrease the production costs of Cu(In,Ga)Se{sub 2} (CIGSe) thin films solar cell technology. In the present study, the electronic transport in submicron CIGSe-based devices has been investigated and compared to that of standard devices. It is observed that when the absorber is around 0.5??m-thick, tunnelling enhanced interface recombination dominates, which harms cells energy conversion efficiency. It is also shown that by varying either the properties of the Mo back contact or the characteristics of 3-stage growth processing, one can shift the dominating recombination mechanism from interface to space charge region and thereby improve the cells efficiency. Discussions on these experimental facts led to the conclusions that 3-stage process implies the formation of a CIGSe/CIGSe homo-interface, whose location as well as properties rule the device operation; its influence is enhanced in submicron CIGSe based solar cells.

  8. Excited state carrier dynamics in CdS{sub x}Se{sub 1-x} semisconductor alloys as studied by ultrafast fluorescence spectroscopy

    SciTech Connect (OSTI)

    Gadd, S.E.

    1995-08-01T23:59:59.000Z

    This dissertation discusses studies of the electron-hole pair dynamics of CdS{sub x}Se{sub 1-x} semiconductor alloys for the entire compositional range from x = 1 to x = 0 as examined by the ultrafast fluorescence techniques of time correlated single photon counting and fluorescence upconversion. Specifically, samples with x = 1, .75, .5, .25, and 0 were studied each at a spread of wavelengths about its respective emission maximum which varies according to {lambda} = 718nm - 210x nm. The decays of these samples were found to obey a Kohlrausch distribution, exp [(t/{tau}){sup {beta}}], with the exponent 3 in the range .5-.7 for the alloys. These results are in agreement with those expected for localization due to local potential variations resulting from the random distribution of sulfur and selenium atoms on the element VI A sub-lattice. This localization can be understood in terms of Anderson localization of the holes in states whose energy distribution tails into the forbidden energy band-gap. Because these states have energy dependent lifetimes, the carriers can decay via many parallel channels. This distribution of channels is the ultimate source of the Kohlrausch form of the fluorescence decays.

  9. Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV

    E-Print Network [OSTI]

    Aggarwal, Kanti M

    2013-01-01T23:59:59.000Z

    We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV. The {\\sc grasp} (general-purpose relativistic atomic structure package) is adopted for calculating energy levels and radiative rates. For determining the collision strengths, and subsequently the excitation rates, the Dirac Atomic R-matrix Code ({\\sc darc}) is used. Oscillator strengths, radiative rates and line strengths are reported for all E1, E2, M1 and M2 transitions among the lowest 49 levels of each ion. Additionally, theoretical lifetimes are provided for all 49 levels of the above five ions. Collision strengths are averaged over a Maxwellian velocity distribution and the effective collision strengths obtained listed over a wide temperature range up to 10$^{8}$ K. Comparisons are made with similar data obtained using the Flexible Atomic Code ({\\sc fac}) to highlight the importance of resonances, included in calcul...

  10. Beta-decay properties of neutron-rich Ge, Se, Kr, Sr, Ru, and Pd isotopes from deformed quasiparticle random-phase approximation

    E-Print Network [OSTI]

    P. Sarriguren

    2015-04-07T23:59:59.000Z

    Beta-decay properties of even and odd-A neutron-rich Ge, Se, Kr, Sr, Ru, and Pd isotopes involved in the astrophysical rapid neutron capture process are studied within a deformed proton-neutron quasiparticle random-phase approximation. The underlying mean field is described self-consistently from deformed Skyrme Hartree-Fock calculations with pairing correlations. Residual interactions in the particle-hole and particle-particle channels are also included in the formalism. The isotopic evolution of the various nuclear equilibrium shapes and the corresponding charge radii are investigated in all the isotopic chains. The energy distributions of the Gamow-Teller strength as well as the beta-decay half-lives are discussed and compared with the available experimental information. It is shown that nuclear deformation plays a significant role in the description of the decay properties in this mass region. Reliable predictions of the strength distributions are essential to evaluate decay rates in astrophysical scenarios.

  11. Determining conductivity and mobility values of individual components in multiphase composite Cu{sub 1.97}Ag{sub 0.03}Se

    SciTech Connect (OSTI)

    Day, Tristan W.; Brown, David R.; Snyder, G. Jeffrey, E-mail: jsnyder@caltech.edu [Department of Materials Science, California Institute of Technology, MC 309-81, Pasadena, California 91106 (United States); Zeier, Wolfgang G. [Department of Materials Science, California Institute of Technology, MC 309-81, Pasadena, California 91106 (United States); Department of Chemistry, University of Southern California, Seeley G. Mudd Bldg., 3620 McClintock Ave., Los Angeles, California 90089-1062 (United States); Melot, Brent C. [Department of Chemistry, University of Southern California, Seeley G. Mudd Bldg., 3620 McClintock Ave., Los Angeles, California 90089-1062 (United States)

    2014-10-27T23:59:59.000Z

    The intense interest in phase segregation in thermoelectrics as a means to reduce the lattice thermal conductivity and to modify the electronic properties from nanoscale size effects has not been met with a method for separately measuring the properties of each phase assuming a classical mixture. Here, we apply effective medium theory for measurements of the in-line and Hall resistivity of a multiphase composite, in this case Cu{sub 1.97}Ag{sub 0.03}Se. The behavior of these properties with magnetic field as analyzed by effective medium theory allows us to separate the conductivity and charge carrier mobility of each phase. This powerful technique can be used to determine the matrix properties in the presence of an unwanted impurity phase, to control each phase in an engineered composite, and to determine the maximum carrier concentration change by a given dopant, making it the first step toward a full optimization of a multiphase thermoelectric material and distinguishing nanoscale effects from those of a classical mixture.

  12. Investigation of deep-level defects in Cu(In,Ga)Se{sub 2} thin films by a steady-state photocapacitance method

    SciTech Connect (OSTI)

    Hu, Xiaobo, E-mail: hxb1314@gmail.com; Sakurai, Takeaki; Akimoto, Katsuhiro [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Yamada, Akimasa; Ishizuka, Shogo; Niki, Sigeru [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2014-10-28T23:59:59.000Z

    The properties of defect levels located 0.8?eV above the valence band in Cu(In{sub 1?x},Ga{sub x})Se{sub 2} thin films were investigated by a steady-state photocapacitance method. When illuminated by light with a photon energy of 0.8?eV at 60?K, a fast increase, followed by a slow increase, was observed in the photocapacitance transients of all samples. Upon being re-exposed, samples with a low bandgap energy showed a slow decrease in photocapacitance transients. These observations were interpreted using a configuration coordinate model assuming two states for the 0.8?eV defect: a stable state D and its metastable state D* with a large lattice relaxation. The difference in the evolution mechanisms of the photocapacitance transients was attributed to the difference in the optical transition of carriers between the two states of the 0.8?eV defect and the valence and conduction bands.

  13. The superionic phase transitions in (NH{sub 4}){sub 3}H(SeO{sub 4}){sub 2} under hydrostatic pressure up to 400?MPa

    SciTech Connect (OSTI)

    Lindner, ?.; Zdanowska-Fr?czek, M., E-mail: mzf@ifmpan.poznan.pl; Paw?owski, A.; Fr?czek, Z. J. [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, Pozna? 60-179 (Poland)

    2014-10-28T23:59:59.000Z

    The effect of hydrostatic pressure on proton conductivity of (NH{sub 4}){sub 3}H(SeO{sub 4}){sub 2} superionic crystal was studied in a wide temperature range and different isobaric conditions by means of impedance spectroscopy method. The measurements were performed along the trigonal c axis of the crystal, i.e., along the direction perpendicular to the plane in which, in the superionic phases, a dynamically disordered H-bond network is formed. The obtained pressure-temperature phase diagram is linear with increasing pressure. The triple point, which is the point of coexistence of the three phases: ferroelastic phase IV, ferroelastic phase III, and superionic phase II was found at p?=?116.3?MPa and T?=?287.3?K. High pressure leads to increase in the temperature range of stability of both superionic phases and to a drastic decrease in the temperature width of the ferroelastic phase III. With increasing pressure, the range of the superionic phase II expands at the expense of the range of the ferroelastic phase III, which is unstable and vanishes at the triple point.

  14. Mechanical and thermal properties of h-MX{sub 2} (M?=?Cr, Mo, W; X?=?O, S, Se, Te) monolayers: A comparative study

    SciTech Connect (OSTI)

    Çak?r, Deniz, E-mail: deniz.cakir@uantwerpen.be; Peeters, François M., E-mail: francois.peeters@uantwerpen.be [Department of Physics, University of Antwerp, 2610 Antwerpen (Belgium); Sevik, Cem, E-mail: csevik@anadolu.edu.tr [Department of Mechanical Engineering, Faculty of Engineering, Anadolu University, Eskisehir TR 26555 (Turkey)

    2014-05-19T23:59:59.000Z

    Using density functional theory, we obtain the mechanical and thermal properties of MX{sub 2} monolayers (where M?=?Cr, Mo, W and X?=?O, S, Se, Te). The ?-centered phonon frequencies (i.e., A{sub 1}, A{sub 2}{sup ?}, E?, and E?), relative frequency values of A{sub 1}, and E? modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures.

  15. Thickness Effect of Al-Doped ZnO Window Layer on Damp Heat Stability of CuInGaSe2 Solar Cells: Preprint

    SciTech Connect (OSTI)

    Pern, F. J.; Mansfield, L.; DeHart, C.; Glick, S. H.; Yan, F.; Noufi, R.

    2011-07-01T23:59:59.000Z

    We investigated the damp heat (DH) stability of CuInGaSe2 (CIGS) solar cells as a function of thickness of the Al-doped ZnO (AZO) window layer from the 'standard' 0.12 ?m to a modest 0.50 ?m over an underlying 0.10-?m intrinsic ZnO buffer layer. The CIGS cells were prepared with external electrical contact using fine Au wire to the tiny 'standard' Ni/Al (0.05 ?m/3 ?m) metal grid contact pads. Bare cell coupons and sample sets encapsulated in a specially designed, Al-frame test structure with an opening for moisture ingress control using a TPT backsheet were exposed to DH at 85oC and 85% relative humidity, and characterized by current-voltage (I-V), quantum efficiency (QE), and (electrochemical) impedance spectroscopy (ECIS). The results show that bare cells exhibited rapid degradation within 50-100 h, accompanied by film wrinkling and delamination and corrosion of Mo and AlNi grid, regardless of AZO thickness. In contrast, the encapsulated cells did not show film wrinkling, delamination, and Mo corrosion after 168 h DH exposure; but the trend of efficiency degradation rate showed a weak correlation to the AZO thickness.

  16. Influence of Damp Heat on the Electrical, Optical, and Morphological Properties of Encapsulated CuInGaSe2 Devices: Preprint

    SciTech Connect (OSTI)

    Sundaramoorthy, R.; Pern, F. J.; Teeter, G.; Li, J. V.; Young, M.; Kuciauskas, D.; Call, N.; Yan, F.; To, B.; Johnston, S.; Noufi, R.; Gessert, T. A.

    2011-08-01T23:59:59.000Z

    CuInGaSe2 (CIGS) devices, encapsulated with different backsheets having different water vapor transmission rates (WVTR), were exposed to damp heat (DH) at 85C and 85% relative humidity (RH) and characterized periodically to understand junction degradation induced by moisture ingress. Performance degradation of the devices was primarily driven by an increase in series resistance within first 50 h of exposure, resulting in a decrease in fill factor and, accompanied loss in carrier concentration and widening of depletion width. Surface analysis of the devices after 700-h DH exposure showed the formation of Zn(OH)2 from hydrolysis of the Al-doped ZnO (AZO) window layer by the moisture, which was detrimental to the collection of minority carriers. Minority carrier lifetimes observed for the CIGS devices using time resolved photoluminescence (TRPL) remained relatively long after DH exposure. By etching the DH-exposed devices and re-fabricating with new component layers, the performance of reworked devices improved significantly, further indicating that DH-induced degradation of the AZO layer and/or the CdS buffer was the primary performance-degrading factor.

  17. Intermixing at the absorber-buffer layer interface in thin-film solar cells: The electronic effects of point defects in Cu(In,Ga)(Se,S){sub 2} and Cu{sub 2}ZnSn(Se,S){sub 4} devices

    SciTech Connect (OSTI)

    Varley, J. B.; Lordi, V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-08-14T23:59:59.000Z

    We investigate point defects in the buffer layers CdS and ZnS that may arise from intermixing with Cu(In,Ga)(S,Se){sub 2} (CIGS) or Cu{sub 2}ZnSn(S,Se){sub 4} (CZTS) absorber layers in thin-film photovoltaics. Using hybrid functional calculations, we characterize the electrical and optical behavior of Cu, In, Ga, Se, Sn, Zn, Na, and K impurities in the buffer. We find that In and Ga substituted on the cation site act as shallow donors in CdS and tend to enhance the prevailing n-type conductivity at the interface facilitated by Cd incorporation in CIGS, whereas they are deep donors in ZnS and will be less effective dopants. Substitutional In and Ga can favorably form complexes with cation vacancies (A-centers) which may contribute to the “red kink” effect observed in some CIGS-based devices. For CZTS absorbers, we find that Zn and Sn defects substituting on the buffer cation site are electrically inactive in n-type buffers and will not supplement the donor doping at the interface as in CIGS/CdS or ZnS devices. Sn may also preferentially incorporate on the S site as a deep acceptor in n-type ZnS, which suggests possible concerns with absorber-related interfacial compensation in CZTS devices with ZnS-derived buffers. Cu, Na, and K impurities are found to all have the same qualitative behavior, most favorably acting as compensating acceptors when substituting on the cation site. Our results suggest one beneficial role of K and Na incorporation in CIGS or CZTS devices is the partial passivation of vacancy-related centers in CdS and ZnS buffers, rendering them less effective interfacial hole traps and recombination centers.

  18. High temperature redox reactions with uranium: Synthesis and characterization of Cs(UO{sub 2})Cl(SeO{sub 3}), Rb{sub 2}(UO{sub 2}){sub 3}O{sub 2}(SeO{sub 3}){sub 2}, and RbNa{sub 5}U{sub 2}(SO{sub 4}){sub 7}

    SciTech Connect (OSTI)

    Babo, Jean-Marie [Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390 (United States); Department of Civil and Environmental Engineering and Earth Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States); Albrecht-Schmitt, Thomas E., E-mail: talbrechtschmitt@gmail.com [Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390 (United States)

    2013-10-15T23:59:59.000Z

    Cs(UO{sub 2})Cl(SeO{sub 3}) (1), Rb{sub 2}(UO{sub 2}){sub 3}O{sub 2}(SeO{sub 3}){sub 3} (2), and RbNa{sub 5}U{sub 2}(SO{sub 4}){sub 7} (3) single crystals were synthesized using CsCl, RbCl, and a CuCl/NaCl eutectic mixture as fluxes, respectively. Their lattice parameters and space groups are as follows: P2{sub 1}/n (a=6.548(1) Å, b=11.052(2) Å, c=10.666(2) Å and ?=93.897(3)°), P1{sup ¯} (a=7.051(2) Å, b=7.198(2) Å, c=8.314(2) Å, ?=107.897(3)°, ?=102.687(3)° and ?=100.564(3)°) and C2/c (a=17.862(4) Å, b=6.931(1) Å, c=20.133(4) Å and ?=109.737(6)°. The small anionic building units found in these compounds are SeO{sub 3}{sup 2?} and SO{sub 4}{sup 2?} tetrahedra, oxide, and chloride. The crystal structure of the first compound is composed of [(UO{sub 2}){sub 2}Cl{sub 2}(SeO{sub 3}){sub 2}]{sup 2?} chains separated by Cs{sup +} cations. The structure of (2) is constructed from [(UO{sub 2}){sub 3}O{sub 11}]{sup 16?} chains further connected through selenite units into layers stacked perpendicularly to the [0 1 0] direction, with Rb{sup +} cations intercalating between them. The structure of compound (3) is made of uranyl sulfate layers formed by edge and vertex connections between dimeric [U{sub 2}O{sub 16}] and [SO{sub 4}] polyhedra. These layers contain unusual sulfate–metal connectivity as well as large voids. - Graphical abstract: A new family of uranyl selenites and sulfates has been prepared by high-temperature redox reactions. This compounds display new bonding motifs. Display Omitted - Highlights: • Low-dimensional Uranyl Oxoanion compounds. • Conversion of U(IV) to U(VI) at high temperatures. • Dimensional reduction by both halides and stereochemically active lone-pairs.

  19. Cu(In,Ga)Se2 alloys are the leading choice for absorber layers in high-efficiency thin film solar cells due to their direct gap, high absorption

    E-Print Network [OSTI]

    Rockett, Angus

    film solar cells due to their direct gap, high absorption coefficient and excellent thermal stability Cu(In,Ga)Se2 are used to interpret PL results. ·No evidence of band-to-band transitions (rare in CIGS

  20. Structural properties of Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} topological insulators grown by molecular beam epitaxy on GaAs(001) substrates

    SciTech Connect (OSTI)

    Liu, X.; Leiner, J.; Dobrowolska, M.; Furdyna, J. K. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Smith, D. J. [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Fan, J. [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Center for Photonics Innovation, Arizona State University, Tempe, Arizona 85287 (United States); Zhang, Y.-H. [Center for Photonics Innovation, Arizona State University, Tempe, Arizona 85287 (United States); School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Cao, H.; Chen, Y. P. [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); Kirby, B. J. [Center for Neutron Research, NIST, Gaithersburg, Maryland 20899 (United States)

    2011-10-24T23:59:59.000Z

    Thin films of Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} have been grown on deoxidized GaAs(001) substrates using molecular beam epitaxy. Cross-sectional transmission electron microscopy established the highly parallel nature of the Te(Se)-Bi-Te(Se)-Bi-Te(Se) quintuple layers deposited on the slightly wavy GaAs substrate surface and the different crystal symmetries of the two materials. Raman mapping confirmed the presence of the strong characteristic peaks reported previously for these materials in bulk form. The overall quality of these films reveals the potential of combining topological insulators with ferromagnetic semiconductors for future applications.

  1. Por ms de 30 aos, el programa de CU Wizards ha presentado shows mensuales GRATIS que entretienen e informan a los nios sobre las maravillas de la ciencia. Estos shows interactivos se

    E-Print Network [OSTI]

    Lineberger, W. Carl

    e informan a los niños sobre las maravillas de la ciencia. Estos shows interactivos se presentan una Harvey "Ilusión y Realidad: La Ciencia de la Percepción" Duane G1B30 10/18/2014 Prof. Veronica Bierbaum

  2. Hoje no faltam rankingspara avaliar as universidades. J ningum se pode queixar de dar tiros no escuro quando escolhe a escola onde quer fazer a licenciatura ou o mestrado.

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Hoje não faltam rankingspara avaliar as universidades. Já ninguém se pode queixar de dar tiros atenção quando quiser fazer o mestrado. Nessa altura deve começar a dar atenção aos rankings para saber

  3. Probing structure-induced optical behavior in a new class of self-activated luminescent 0D/1D CaWO? metal oxide – CdSe nanocrystal composite heterostructures

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

    Han, Jinkyu; McBean, Coray; Wang, Lei; Hoy, Jessica; Jaye, Cherno; Liu, Haiqing; Li, Zhuo-Qun; Sfeir, Matthew Y.; Fischer, Daniel A.; Taylor, Gordon T.; et al

    2015-02-10T23:59:59.000Z

    In this report, we synthesize and characterize the structural and optical properties of novel heterostructures composed of (i) semiconducting nanocrystalline CdSe quantum dot (QDs) coupled with (ii) both one and zero-dimensional (1D and 0D) motifs of self-activated luminescence CaWO? metal oxides. Specifically, ~4 nm CdSe QDs have been anchored onto (i) high-aspect ratio 1D nanowires, measuring ~230 nm in diameter and ~3 ?m in length, as well as onto (ii) crystalline 0D nanoparticles (possessing an average diameter of ~ 80 nm) of CaWO? through the mediation of 3-mercaptopropionic acid (MPA) as a connecting linker. Composite formation was confirmed by complementarymore »electron microscopy and spectroscopy (i.e. IR and Raman) data. In terms of luminescent properties, our results show that our 1D and 0D heterostructures evince photoluminescence (PL) quenching and shortened PL lifetimes of CaWO? as compared with unbound CaWO?. We propose that a photo-induced electron transfer process occurs from CaWO? to CdSe QDs, a scenario which has been confirmed by NEXAFS measurements and which highlights a decrease in the number of unoccupied orbitals in the conduction bands of CdSe QDs. By contrast, the PL signature and lifetimes of MPA-capped CdSe QDs within these heterostructures do not exhibit noticeable changes as compared with unbound MPA-capped CdSe QDs. The striking difference in optical behavior between CaWO? nanostructures and CdSe QDs within our heterostructures can be correlated with the relative positions of their conduction and valence energy band levels. In addition, the PL quenching behaviors for CaWO? within the heterostructure configuration were examined by systematically varying (i) the quantities and coverage densities of CdSe QDs as well as (ii) the intrinsic morphology (and by extension, the inherent crystallite size) of CaWO? itself.« less

  4. Thermoelectric properties of n-type Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} fabricated by mechanical alloying and hot pressing

    SciTech Connect (OSTI)

    Kim, H.J.; Choi, J.S.; Oh, T.S.; Hyun, D.B.

    1997-07-01T23:59:59.000Z

    Thermoelectric properties of polycrystalline Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} (0.05 {le} x {le} 0.25), fabricated by mechanical alloying and hot pressing, have been investigated. Formation of n-type Bi{sub 2}(Te{sub 0.9}Se{sub 0.1}){sub 3} alloy powders was completed by mechanical alloying for 3 hours at ball-to-material ratio of 5:1, and processing time for Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} formation increased with Bi{sub 2}Se{sub 3} content x. Figure-of-merit of Bi{sub 2}(Te{sub 0.9}Se{sub 0.1}) was markedly increased by hot pressing at temperatures above 450 C, and maximum value of 1.9 x 10{sup {minus}3}/K was obtained by hot pressing at 550 C. With addition of 0.015 wt% Bi as acceptor dopant, figure-of-merit of Bi{sub 2}(Te{sub 0.9}Se{sub 0.1}){sub 3} was hot pressed at 550 C, could be improved to 2.1 x 10{sup {minus}3}/K. When Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} was hot pressed at 550 C, figure-of-merit increased from 1.14 x 10{sup {minus}3}/K to 1.92 x 10{sup {minus}3}/K with increasing Bi{sub 2}Se{sub 3} content x from 0.05 to 0.15, and then decreased to 1.30 x 10{sup {minus}3}/K for x = 0.25 composition.

  5. Prdidas de insercin en diferentes tipos de materiales y rboles El gran avance que se est produciendo en los sistemas WiFi y WiMAX, y su habitual

    E-Print Network [OSTI]

    Autonoma de Madrid, Universidad

    trabajo que operan estos sistemas. Debido a la escasa información que existe con respecto a estas pérdidas escenarios, tanto interiores como exteriores, para las bandas de trabajo de 2.4 GHz, 3.3 GHz y 5.5 GHz. Este estudio se realizará a partir de enlaces de corta distancia, donde el obstáculo se interponga directamente

  6. Probing structure-induced optical behavior in a new class of self-activated luminescent 0D/1D CaWO? metal oxide – CdSe nanocrystal composite heterostructures

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

    Han, Jinkyu [Brookhaven National Lab. (BNL), Upton, NY (United States); McBean, Coray [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Wang, Lei [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Hoy, Jessica [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Jaye, Cherno [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Liu, Haiqing [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Li, Zhuo-Qun [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Sfeir, Matthew Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, Daniel A. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Taylor, Gordon T. [State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Misewich, James A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wong, Stanislaus S. [Brookhaven National Lab. (BNL), Upton, NY (United States); State Univ. of New York at Stony Brook, Stony Brook, NY (United States)

    2015-02-10T23:59:59.000Z

    In this report, we synthesize and characterize the structural and optical properties of novel heterostructures composed of (i) semiconducting nanocrystalline CdSe quantum dot (QDs) coupled with (ii) both one and zero-dimensional (1D and 0D) motifs of self-activated luminescence CaWO? metal oxides. Specifically, ~4 nm CdSe QDs have been anchored onto (i) high-aspect ratio 1D nanowires, measuring ~230 nm in diameter and ~3 ?m in length, as well as onto (ii) crystalline 0D nanoparticles (possessing an average diameter of ~ 80 nm) of CaWO? through the mediation of 3-mercaptopropionic acid (MPA) as a connecting linker. Composite formation was confirmed by complementary electron microscopy and spectroscopy (i.e. IR and Raman) data. In terms of luminescent properties, our results show that our 1D and 0D heterostructures evince photoluminescence (PL) quenching and shortened PL lifetimes of CaWO? as compared with unbound CaWO?. We propose that a photo-induced electron transfer process occurs from CaWO? to CdSe QDs, a scenario which has been confirmed by NEXAFS measurements and which highlights a decrease in the number of unoccupied orbitals in the conduction bands of CdSe QDs. By contrast, the PL signature and lifetimes of MPA-capped CdSe QDs within these heterostructures do not exhibit noticeable changes as compared with unbound MPA-capped CdSe QDs. The striking difference in optical behavior between CaWO? nanostructures and CdSe QDs within our heterostructures can be correlated with the relative positions of their conduction and valence energy band levels. In addition, the PL quenching behaviors for CaWO? within the heterostructure configuration were examined by systematically varying (i) the quantities and coverage densities of CdSe QDs as well as (ii) the intrinsic morphology (and by extension, the inherent crystallite size) of CaWO? itself.

  7. Hg and Se capture and fly ash carbons from combustion of complex pulverized feed blends mainly of anthracitic coal rank in Spanish power plants

    SciTech Connect (OSTI)

    I. Surez-Ruiz; J.C. Hower; G.A. Thomas [Instituto Nacional del Carbon (INCAR-CSIC), Oviedo (Spain)

    2007-01-15T23:59:59.000Z

    In this work, the petrology and chemistry of fly ashes produced in a Spanish power plant from the combustion of complex pulverized feed blends made up of anthracitic/meta-anthracitic coals, petroleum, and natural coke are investigated. It was found that the behavior of fly ash carbons derived from anthracitic coals follows relatively similar patterns to those established for the carbons from the combustion of bituminous coals. Fly ashes were sampled in eight hoppers from two electrostatic precipitator (ESP) rows. The characterization of the raw ashes and their five sieved fractions (from {gt}150 to {lt}25 {mu}m) showed that glassy material, quartz, oxides, and spinels in different proportions are the main inorganic components. As for the organic fraction, the dominant fly ash carbons are anisotropic carbons, mainly unburned carbons derived from anthracitic vitrinite. The concentration of Se and Hg increased in ashes of the second ESP row, this increase being related to the higher proportion of anisotropic unburned carbons, particularly those largely derived from anthracitic vitrinite in the cooler ashes of the ESP (second row) and also related to the decrease in the flue gas temperature. This suggests that the flue gas temperature plays a major role in the concentration of mercury for similar ratios of unburned carbons. It was also found that Hg is highly concentrated in the medium-coarser fractions of the fly ashes ({gt} 45 {mu}m), there being a positive relationship between the amount of these carbons, which are apparently little modified during the combustion process, in the medium-coarse fractions of the ashes and the Hg retention. According to the results obtained, further research on this type of fly ash could be highly productive. 28 refs., 10 figs., 8 tabs.

  8. Rare-earth transition-metal gallium chalcogenides RE{sub 3}MGaCh{sub 7} (M=Fe, Co, Ni; Ch=S, Se)

    SciTech Connect (OSTI)

    Rudyk, Brent W.; Stoyko, Stanislav S.; Oliynyk, Anton O.; Mar, Arthur, E-mail: arthur.mar@ualberta.ca

    2014-02-15T23:59:59.000Z

    Six series of quaternary rare-earth transition-metal chalcogenides RE{sub 3}MGaCh{sub 7} (M=Fe, Co, Ni; Ch=S, Se), comprising 33 compounds in total, have been prepared by reactions of the elements at 1050 °C (for the sulphides) or 900 °C (for the selenides). They adopt noncentrosymmetric hexagonal structures (ordered Ce{sub 3}Al{sub 1.67}S{sub 7}-type, space group P6{sub 3}, Z=2) with cell parameters in the ranges of a=9.5–10.2 Å and c=6.0–6.1 Å for the sulphides and a=10.0–10.5 Å and c=6.3–6.4 Å for the selenides as refined from powder X-ray diffraction data. Single-crystal structures were determined for five members of the sulphide series RE{sub 3}FeGaS{sub 7} (RE=La, Pr, Tb) and RE{sub 3}CoGaS{sub 7} (RE=La, Tb). The highly anisotropic crystal structures consist of one-dimensional chains of M-centred face-sharing octahedra and stacks of Ga-centred tetrahedra all pointing in the same direction. Magnetic measurements on the sulphides reveal paramagnetic behaviour in some cases and long-range antiferromagnetic behaviour with low Néel temperatures (15 K or lower) in others. Ga L-edge XANES spectra support the presence of highly cationic Ga tetrahedral centres with a tendency towards more covalent Ga–Ch character on proceeding from the sulphides to the selenides. Band structure calculations on La{sub 3}FeGaS{sub 7} indicate that the electronic structure is dominated by Fe 3d-based states near the Fermi level. - Graphical abstract: The series of chalcogenides RE{sub 3}MGaS{sub 7}, which form for a wide range of rare-earth and transition metals (M=Fe, Co, Ni), adopt highly anisotropic structures containing chains of M-centred octahedra and stacks of Ga-centred tetrahedra. Display Omitted - Highlights: • Six series (comprising 33 compounds) of chalcogenides RE{sub 3}MGaCh{sub 7} were prepared. • They adopt noncentrosymmetric hexagonal structures with high anisotropy. • Most compounds are paramagnetic; some show antiferromagnetic ordering. • Ga L-edge XANES confirms presence of cationic Ga species.

  9. Crystal structure and magnetic properties of two new cobalt selenite halides: Co{sub 5}(SeO{sub 3}){sub 4} X {sub 2} (X=Cl, Br)

    SciTech Connect (OSTI)

    Becker, Richard [Department of Inorganic Chemistry, Stockholm University, S-106 91 Stockholm (Sweden)], E-mail: richard@inorg.su.se; Prester, Mladen [Institute of Physics, P.O. Box 304, HR-10000 Zagreb (Croatia); Berger, Helmuth [Institut de Physique de la Matiere Complexe, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Hui Lin, Ping [Institut de Physique de la Matiere Complexe, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Institute of Physics, Academia Sinica Nankang, Taipei 11529, Taiwan, ROC (China); Johnsson, Mats [Department of Inorganic Chemistry, Stockholm University, S-106 91 Stockholm (Sweden); Drobac, Djuro [Institute of Physics, P.O. Box 304, HR-10000 Zagreb (Croatia); Zivkovic, Ivica [Institute of Physics, P.O. Box 304, HR-10000 Zagreb (Croatia)

    2007-03-15T23:59:59.000Z

    Two new isostructural cobalt selenite halides Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} have been synthesized. They crystallize in the triclinic system space group P-1 with the following lattice parameters for Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2}: a=6.4935(8) A, b=7.7288(8) A, c=7.7443(10) A, {alpha}=66.051(11){sup o}, {beta}=73.610(11){sup o}, {gamma}=81.268(9){sup o}, and Z=1. The crystal structures were solved from single-crystal X-ray data, R1=3.73 and 4.03 for Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}, respectively. The new compounds are isostructural to Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}. Magnetic susceptibility measurements on oriented single-crystalline samples show anisotropic response in a broad temperature range. The anisotropic susceptibility is quantitatively interpreted within the zero-field splitting schemes for Co{sup 2+} and Ni{sup 2+} ions. Sharp low-temperature susceptibility features, at T {sub N}=18 and 20 K for Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}, respectively, are ascribed to antiferromagnetic ordering in a minority magnetic subsystem. In isostructural Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} magnetically ordered subsystem represents a majority fraction (T {sub N}=46 K). Nevertheless, anisotropic susceptibility of Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} is dominated at low temperatures by a minority fraction, subject to single-ion anisotropy effects and increasing population of S{sub z} =0 (singlet) ground state of octahedrally coordinated Ni{sup 2+}. - Graphical abstract: Two new iso-structural cobalt selenite halides Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} have been synthesized which are iso-structural to Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}. Magnetic susceptibility measurements on oriented single-crystalline samples show anisotropic response in a broad temperature range, revealing significant single-ion anisotropy effects.

  10. Synthesis, structure and properties of the oxychalcogenide series A{sub 4}O{sub 4}TiSe{sub 4} (A=Sm, Gd, Tb, Dy, Ho, Er and Y)

    SciTech Connect (OSTI)

    Tuxworth, A.J.; Evans, J.S.O., E-mail: john.evans@durham.ac.uk

    2014-02-15T23:59:59.000Z

    Seven oxyselenide materials have been synthesised with composition A{sub 4}O{sub 4}TiSe{sub 4} (A=Sm, Gd–Er, Y) via solid state reactions of A{sub 2}O{sub 3}, TiSe{sub 2} and Se at 900 °C. They are all isostructural with Gd{sub 4}O{sub 4}TiSe{sub 4}. Structures have been refined from powder X-ray diffraction data and have monoclinic C2/m symmetry with unit cell parameters of a?15.7 Å, b?3.75 Å, c?9.65 Å and ??117.5°. They contain infinite ribbons of edge-sharing A{sub 4}O and A{sub 3}TiO tetrahedra 4 units wide, which are linked by chains of TiSe{sub 4}O{sub 2} edge-sharing octahedra. Compositions A=Gd–Ho, Y are semiconductors with conductivities 1–3 Sm{sup ?1} at 300 K, with electronic band gaps of between 0.25 and 0.37 eV. Magnetic susceptibility is reported from 1.8 K to 300 K for compositions A=Gd–Ho. Rare earth moments appear to order antiferromagnetically at low temperatures with Gd and Tb showing evidence of ferromagnetism due to spin canting over a narrow temperature range close to T{sub N}. - Graphical abstract: Illustration of the A{sub 4}O{sub 4}TiSe{sub 4} crystal structure (C2/m symmetry), A{sub 4}O and A{sub 3}TiO edge sharing tetrahedral ribbons in red, chains of edge-sharing TiSe{sub 4}O{sub 2} in blue. Rare earth=green, titanium=blue, selenium=yellow, and oxygen=red. Display Omitted - Highlights: • Seven materials with A{sub 4}O{sub 4}TiSe{sub 4} (A=Sm, Gd–Er, Y) have been synthesised as bulk phases for the first time. • Materials are semiconductors and order antiferromagnetically at ?4 K. • Structure contains M{sub 4}O tetrahedral ribbons and TiSe{sub 4}O{sub 2} 1D octahedral chains.

  11. Effect of annealing on the kinetic properties and band parameters of Hg{sub 1?x?y}Cd{sub x}Eu{sub y}Se semiconductor crystals

    SciTech Connect (OSTI)

    Kovalyuk, T. T., E-mail: tarik-1006@mail.ru; Maistruk, E. V.; Maryanchuk, P. D. [Chernivtsy National University (Ukraine)

    2014-12-15T23:59:59.000Z

    The results of studies of the kinetic properties of Hg{sub 1?x?y}Cd{sub x}Eu{sub y}Se semiconductor crystals in the ranges of temperatures T = 77–300 K and magnetic fields H = 0.5–5 kOe before and after heat treatment of the samples in Se vapors are reported. It is established that annealing of the samples in Se vapors induces a decrease in the electron concentration. From the concentration dependence of the electron effective mass at the Fermi level, the band gap, the matrix element of interband interaction, and the electron effective mass at the bottom of the conduction band are determined.

  12. Observation of an electron band above the Fermi level in FeTe{sub 0.55}Se{sub 0.45} from in-situ surface doping

    SciTech Connect (OSTI)

    Zhang, P.; Ma, J.; Qian, T. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Richard, P., E-mail: p.richard@iphy.ac.cn; Ding, H., E-mail: dingh@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Xu, N. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Paul Scherrer Institut, Swiss Light Source, CH-5232 Villigen PSI (Switzerland); Xu, Y.-M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fedorov, A. V.; Denlinger, J. D. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Gu, G. D. [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2014-10-27T23:59:59.000Z

    We used in-situ potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe{sub 0.55}Se{sub 0.45}. The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily electron-doped KFe{sub 2?x}Se{sub 2} compound.

  13. Race and Ethnicity and Latin America's United Nations Millennium Development Goals

    E-Print Network [OSTI]

    Telles, Edward E.

    2007-01-01T23:59:59.000Z

    but very unlikely for Bolivia, Colombia, Paraguay andreduction in Mexico, Bolivia and Guatemala were slower thanin Mexico, Guatemala, Bolivia while blacks and mulattos are

  14. L'agriculture familiale se dfinit par le recours quasi-exclusif du travail familial, sans sa-laris permanents,et par des interrelations fortes entre les agriculteurs et leur exploitation.Le

    E-Print Network [OSTI]

    1 #12;L'agriculture familiale se définit par le recours quasi-exclusif à du travail familial, sans agricultures familiales. Avec ses 500 millions d'exploitations, elles font vivre 2,6 milliards de personnes et, les agricultures familiales sont présentes sur tous les continents et dans tous les écosystèmes. Cette

  15. Nano-Fabricated Extracellular Matrix Topography could Alter the Cancer Cell Behavior Kasun A. Gardiye Punchihewa1, Se Yong An1, Michael Cho2, Sarah Glover3and Vitali Metlushko1*

    E-Print Network [OSTI]

    Metlushko, Vitali

    . Gardiye Punchihewa1, Se Yong An1, Michael Cho2, Sarah Glover3and Vitali Metlushko1* 1Department Glover. Cancer Cell International 2010, 10:24 This research brings together a team of interdisciplinary biology (Dr. Sarah Glover, UIC College of Medicine), cellular biomechanics and multimodal imaging (Dr

  16. Anomalous transport in an n-type topological insulator ultrathin Bi2Se3 film Toru Hirahara,1,* Yusuke Sakamoto,1 Yasuo Takeichi,2 Hidetoshi Miyazaki,3 Shin-ichi Kimura,3 Iwao Matsuda,2

    E-Print Network [OSTI]

    Hasegawa, Shuji

    Anomalous transport in an n-type topological insulator ultrathin Bi2Se3 film Toru Hirahara,1, 73.61.Ng I. INTRODUCTION Topological insulators have attracted much attention from a wide variety, they are mathematically characterized by the so-called Z2 topological number.1 While the bulk is insulating

  17. Qu es el Sistema Universidad Abierta y Educacin a Distancia (SUAyED)? En su origen, el Sistema Universidad Abierta se concibi como parte integral del proyecto de Reforma Universitaria impulsada por el

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    Islas, León

    ¿Qué es el Sistema Universidad Abierta y Educación a Distancia (SUAyED)? En su origen, el Sistema horario, lugar, edad, trabajo, etcétera, que impedían que cualquier persona que cubriera los requisitos de Estructura Académica de la UNAM, se estableció la Coordinación de Universidad Abierta y Educación a Distancia

  18. Aysen, Chili, 21 Avril 2007 Le 21 Avril 2007 17h53 TU un sisme de magnitude 6.2 se produit dans les environs d'Aysen au sud

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    Vigny, Christophe

    décrochante qui se trouve au voisinage de l'essaim de séismes. Les enregistrements des stations (sismo et GPS moment. Ce laboratoire a pour ambition d'étudier la sismo-tectonique de la subduction Chilienne et s

  19. 174. THE EFFECTS OF RESIDENCE TIME ON THE RETENTION OF ARSENATE BY GOETHITE. S.E. O'Reilly and D.L. Sparks, Department of Plant and Soil Sciences, University

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    Sparks, Donald L.

    174. THE EFFECTS OF RESIDENCE TIME ON THE RETENTION OF ARSENATE BY GOETHITE. S.E. O'Reilly and D on goethite. Batch sorption and desorption studies were conducted at pH 6 for periods up to 2 months. Arsenate sorption increased slowly with time. As residence time between arsenate and goethite increased

  20. Influence of different sulfur to selenium ratios on the structural and electronic properties of Cu(In,Ga)(S,Se){sub 2} thin films and solar cells formed by the stacked elemental layer process

    SciTech Connect (OSTI)

    Mueller, B. J., E-mail: bjm.mueller@web.de [Robert Bosch GmbH, Corporate Research and Advance Engineering, Advanced Functional Materials and Microsystems, D-70839 Gerlingen (Germany); Institute of Micro- and Nanomaterials, University of Ulm, D-89081 Ulm (Germany); Zimmermann, C.; Haug, V., E-mail: veronika.haug@de.bosch.com; Koehler, T.; Zweigart, S. [Robert Bosch GmbH, Corporate Research and Advance Engineering, Advanced Functional Materials and Microsystems, D-70839 Gerlingen (Germany); Hergert, F. [Bosch Solar CISTech GmbH, D-14772 Brandenburg (Germany); Herr, U., E-mail: ulrich.herr@uni-ulm.de [Institute of Micro- and Nanomaterials, University of Ulm, D-89081 Ulm (Germany)

    2014-11-07T23:59:59.000Z

    In this study, we investigate the effect of different elemental selenium to elemental sulfur ratios on the chalcopyrite phase formation in Cu(In,Ga)(S,Se){sub 2} thin films. The films are formed by the stacked elemental layer process. The structural and electronic properties of the thin films and solar cells are analyzed by means of scanning electron microscopy, glow discharge optical emission spectrometry, X-ray diffraction, X-ray fluorescence, Raman spectroscopy, spectral photoluminescence as well as current-voltage, and quantum efficiency measurements. The influence of different S/(S+Se) ratios on the anion incorporation and on the Ga/In distribution is investigated. We find a homogenous sulfur concentration profile inside the film from the top surface to the bottom. External quantum efficiency measurements show that the band edge of the solar cell device is shifted to shorter wavelength, which enhances the open-circuit voltages. The relative increase of the open-circuit voltage with S/(S+Se) ratio is lower than expected from the band gap energy trend, which is attributed to the presence of S-induced defects. We also observe a linear decrease of the short-circuit current density with increasing S/(S+Se) ratio which can be explained by a reduced absorption. Above a critical S/(S+Se) ratio of around 0.61, the fill factor drops drastically, which is accompanied by a strong series resistance increase which may be attributed to changes in the back contact or p-n junction properties.