National Library of Energy BETA

Sample records for guatemala se mencionan

  1. LAS HORMIGAS (HYMENOPTERA: FORMICIDAE) DE GUATEMALA

    E-Print Network [OSTI]

    Miller, Scott

    LAS HORMIGAS (HYMENOPTERA: FORMICIDAE) DE GUATEMALA 1Department of Entomology, University, Universidad de San Carlos de Guatemala, Guatemala, Correo electrónico: laury.saenz@gmail.com MICHAEL G Guatemala y los países colindantes de la región mesoamericana. Se presen- ta una lista actualizada de las

  2. (Consultecnia, Guatemala City (Guatemala)); Altseimer, J.; Thayer...

    Office of Scientific and Technical Information (OSTI)

    Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion) 15 GEOTHERMAL ENERGY; 60 APPLIED LIFE SCIENCES; DEHYDRATORS; DESIGN; OPERATION; PERFORMANCE;...

  3. A New Species of Cryptotriton (Caudata: Plethodontidae) from Eastern Guatemala

    E-Print Network [OSTI]

    Wake, David B.

    A New Species of Cryptotriton (Caudata: Plethodontidae) from Eastern Guatemala Carlos R. Va (Plethodontidae) is described from the mountains of eastern Guatemala. The new species is distinguished from all~as del este de Guatemala. Cryptotriton sierraminensis se distingue de todos los otros miembros de su ge

  4. Perfil Ambiental de Guatemala

    E-Print Network [OSTI]

    Lopez-Carr, David

    Perfil Ambiental de Guatemala Informe sobre el estado del ambiente y bases para su evaluación sistemática Guatemala, 2004 UNIVERSIDAD RAFAEL LANDÍVAR Facultad de Ciencias Ambientales y Agrícolas Instituto de Guatemala Informe sobre el estado del ambiente y bases para su evaluación sistemática ISBN: 99922

  5. VIGILANTE: Violence and Security in Postwar Guatemala

    E-Print Network [OSTI]

    Sharp, Ellen Jane

    2014-01-01

    of Historic Memory Project) 1998 Guatemala: Nunca Más.Guatemala City: ODHA (Human Rightsof the Archbishop of Guatemala). Remijinse, Simone 2002

  6. 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

    2012-01-01

    ¿con qué criterios? ¿Qué escala es la más adecuada para definirlos, a nivel de país, de región, de municipio o de familia? La antropóloga Merlin (2009:304-6) divide la manera de distinguir a los indígenas de los no indígenas en dos categorías: a... es incorrecto políticamente pensar en indios atrasados frente a la economía política modernista; hay que pensar en indígenas cuyas culturas y derechos se deben preservar. Debido a estos cambios, la gente que negaba ser indígena ahora abraza el...

  7. Policy of Primary Health Care in Guatemala

    E-Print Network [OSTI]

    Longchamp, Carla P

    1988-01-01

    26. Simon, Jean-Marie. Guatemala, Eternal Spring, EternalPeace Accords 'Don't Apply‘ In Guatemala”, Leporton Guatemala, March/April, 1966, pp. 3-4. 26. Agency for

  8. Isolation, Integration, and Ethnic Boundaries in Rural Guatemala

    E-Print Network [OSTI]

    Pebley, Anne R.; Goldman, Noreen; Robles, Arodys

    2002-01-01

    Language Revitalization in Guatemala” in S. Garzon, R. M.Maya Cultural Activism in Guatemala. Austin: Univ. of TexasMaya Cultural Activism in Guatemala. Austin: University of

  9. Choices about Treatment for ARI and Diarrhea in Rural Guatemala

    E-Print Network [OSTI]

    Goldman, Noreen; Pebley, Anne R.; Gragnolati, Michele

    2000-01-01

    economic well-being in Guatemala. Unpublished manuscript.diarrhea in highland Guatemala. Medical Anthropology 12(4),symptoms in rural Guatemala. Annales de la Societe. Belge de

  10. Roshni Naik, '09 San Lucas Toliman, Guatemala

    E-Print Network [OSTI]

    Roshni Naik, '09 San Lucas Toliman, Guatemala For six weeks, I spent my summer of service in rural Guatemala on Lake Atitlan. Lake Atitlan is one of the biggest lakes in Guatemala, and it is surrounded I saw the lack of health education and prevention among the rural poor population in Guatemala. I

  11. University of Utah Guatemala Archaeological Research Opportunities

    E-Print Network [OSTI]

    Tipple, Brett

    University of Utah Guatemala Archaeological Research Opportunities Dates: June 20, 2015 thru August 5, 2015 Credits 3 credits per course Course Number: Guatemala Field Research 3 Credit hours Anth Activity Fees: $1350 plus airfare to Guatemala City or Flores/ Santa Elena, Peten, Guatemala Deadline: May

  12. 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

  13. Testimonio transformed : from I, Rigoberta to Guatemala, Nunca más and Guatemala, Memoria del silencio

    E-Print Network [OSTI]

    Metz, Cristina

    2011-01-01

    Palma Murga. eds. ¿Racismo en Guatemala? Abriendo el debatesobre un tema tabú. Guatemala: AVANCSO, 2004. Booth, JohnViolence, and the Crisis in Guatemala: A Case Study in the

  14. Living on Scorched Earth: the Political Ecology of Land Ownership in Guatemala's Northern Lowlands

    E-Print Network [OSTI]

    Ybarra, Megan

    2010-01-01

    perspectivas de desarrollo sostenible en Petén. Guatemala:perspectivas de desarrollo sostenible en Petén. Guatemala:

  15. Karstic mountain almost conquered. [Guatemala

    SciTech Connect (OSTI)

    Not Available

    1982-06-10

    International design and construction teams building a 300-Mw hydroelectric system high in central Guatemala's rugged mountains since 1977 have persevered through karstic-limestone nightmares, logistical bottlenecks and political upheaval to bring the $700-million Rio Chixoy project close to completion. The costly power push, requiring the largest construction effort in Guatemala's modern history, plays a critical role for the future. When all five Pelton-wheel turbines are spinning late next year, their output will more than double electricity production in Central America's poorest, most populous country. Despite numerous delays, design changes and cost increases above the original $240-million bid package, work has progressed to the final stages on a 360-ft-high rockfill dam, 16-mile power tunnel and aboveground powerhouse.

  16. Living on Scorched Earth: the Political Ecology of Land Ownership in Guatemala's Northern Lowlands

    E-Print Network [OSTI]

    Ybarra, Megan

    2010-01-01

    T. , and M. Melville. 1971. Guatemala: the politics of landBajas del Norte de Guatemala: Petén y la Franja Transversaldel Norte. Ciudad de Guatemala: FLACSO, MINUGUA, CONTIERRA.

  17. Norman B. Schwartz. Forest Society: A Social History of Peten, Guatemala. University of Oklahoma Press, 1990.

    E-Print Network [OSTI]

    Herrera, Robinson

    1991-01-01

    A Social History of Peten, Guatemala. University of Oklahomathe highland region of Guatemala, Schwartz worked heavily inon colonial lowland Guatemala. Lamentably these chapters

  18. 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

    2012-01-01

    0622, USA. 2 La Universidad del Valle de Guatemala, VistaHermosa III, GuatemalaCity, Guatemala 01015. 3 Cedar Associates, Menlo Park, CA

  19. Fertility and the Environment in a Natural Resource Dependent Economy: Evidence from Petén, Guatemala

    E-Print Network [OSTI]

    Sutherland, Elizabeth G; Carr, David L; Curtis, Siân L

    2005-01-01

    degradation: The case of Guatemala." Ambio 21: 460-464.tenure in the Petén, Guatemala. Flores, Petén, Fulbrighty recursos naturales. Guatemala, Instituto Nacional de

  20. 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

    2012-01-01

    Surgery Program in Guatemala Clair Brown, Eric Freeman, Kates Cataract Surgery Program in Guatemala 1 Goal: Improve thedaily life for people in Guatemala who do not normally have

  1. From the Past to the Present: The Guatemala STD Study and Multi-Layered Bioethical Critique

    E-Print Network [OSTI]

    Gonzalez, Alicia

    2014-01-01

    Reverby, Susan. “The Guatemala STD Inoculation Studies: WhatService Research in Guatemala: Toward New Scholarship. ”the Maya” in The Guatemala Reader: History, Culture,

  2. The comadrona and response to obstetrical emergencies : maternal mortality in highland Guatemala

    E-Print Network [OSTI]

    Copeland, Margaret Hemphill

    2011-01-01

    related care in rural Guatemala. Ethnicity & Health 5 (1):services in rural Guatemala. Social Science & Medicine.Partthe Marlin mine in western Guatemala. Science of the Total

  3. Experiencing Maya Palaces: Royal Power, Space, and Architecture at Holmul, Guatemala

    E-Print Network [OSTI]

    Mongelluzzo, Ryan

    2011-01-01

    The Ruins of Holmul Guatemala. Peabody Museum, Cambridge.Authentic Maya 2005 Guatemala: Cradle of Mayan Civilization.Period Holmul Region, Guatemala, Vanderbilt University.

  4. Testimonio transformed : from I, Rigoberta to Guatemala, Nunca más and Guatemala, Memoria del silencio

    E-Print Network [OSTI]

    Metz, Cristina

    2011-01-01

    cases it investigated, gender violence always equaled rape.196 Rape in Guatemala was not an aberration; it was an actfurther characterization of rape diverges at a few points.

  5. (Surveying isolated diesel power stations in Guatemala)

    SciTech Connect (OSTI)

    Waddle, D.B.

    1990-02-26

    I travelled to Guatemala City, Guatemala, to lead a team of specialists to study the operating, administrative, and management efficiency of isolated diesel power plants, operated by Instituto Nacional de Electrificacion (INDE). The study is part of a global initiative managed jointly by the Agency for International Development and the World Bank. The power plants were audited, including INDE's largest isolated diesel station, and two, much smaller municipal and privately owned stations. I returned to Oak Ridge on February 22, 1990.

  6. Guatemala: World Oil Report 1991

    SciTech Connect (OSTI)

    Not Available

    1991-08-01

    This paper reports that government officials have been working on changes to the hydrocarbon law to make it easier for operators to explore. In a reform effort, Minister of Energy and Mines Carlos Hutarte brought a new staff dedicated to spurring oil development into office with him. This includes the Directorate of Hydrocarbons, which held a three-day seminar in Dallas, Texas, to acquaint U.S. firms with new policies. Only one company, Basic Resources International, has been operating in Guatemala over the last year. The firm drilled three onshore wells in 1990 for 16,499 ft, including one oil producer. Two further onshore wells are slated this year. Oil production from 14 active wells out of 16 capable averaged 3,943 bpd, up 8.4% from 1989. Reserves are 191 MMbbl.

  7. Short communication Observations of eruptive activity at Santiaguito volcano, Guatemala

    E-Print Network [OSTI]

    Rose, William I.

    Short communication Observations of eruptive activity at Santiaguito volcano, Guatemala Gregg J volcano, Guatemala, from the vantage point of its parent, Santa Mari´a. We have taken 12 h of digital

  8. Geomorphology and natural hazards of the Samala river basin, Guatemala

    E-Print Network [OSTI]

    in Guatemala for their rele- vant assistance during my time together with them. The list of my friends

  9. 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- raceae) evolved in the eastern and central high- lands of Mexico, Guatemala, and the Pacific Coast), and Guatemala (10) (FAOSTAT 2009). California, the fourth largest producer of avocados in the world (FAOSTAT

  10. Surface temperature and spectral measurements at Santiaguito lava dome, Guatemala

    E-Print Network [OSTI]

    Rose, William I.

    Surface temperature and spectral measurements at Santiaguito lava dome, Guatemala Steve T. M, Michigan Technological University, Houghton, Michigan, USA Otoniel Matias INSIVUMEH, Guatemala City, Guatemala Received 4 June 2004; revised 23 July 2004; accepted 20 September 2004; published 13 October 2004

  11. forest certification in guatemala yale school of forestry & environmental studies

    E-Print Network [OSTI]

    forest certification in guatemala yale school of forestry & environmental studies 363 * Fernando@catie.ac.cr ***** Gustavo Pinelo, B.Sc. Coordinator, TREES/ Rainforest Alliance Petén, Guatemala gpinelo@ra.org Forest Certification in Guatemala Fernando Carrera,* Dietmar Stoian,** José Joaquin Campios,*** Julio Morales

  12. Nutritional Assessment of the Elderly of San Pedro Ayampuc, Guatemala: Evaluation of Anthropometry, Biochemistry, and Helminthic Infection

    E-Print Network [OSTI]

    King, Jane E

    1991-01-01

    y Asistencia Social. Guatemala en Cifras de Salud AnuarioSan Pedro Ayampuc, Guatemala: Evaluation of Anthropometry,of San Pedro Ayampuc, Guatemala, without whose enthusiasm

  13. The Obsidian Blade Sequence at El Ujuxte, a Late Preclassic Site on the South Coast of Guatemala

    E-Print Network [OSTI]

    C. Roger Nance; Jan de Leeuw

    2011-01-01

    Industries of Pacific Guatemala and El Salvador: The PacificSociety in Pacific Guatemala: Settlements and Chronologyof the Río Naranjo, Guatemala. Papers of the New World

  14. Impact of integrating HIV and TB care and treatment in a regional tuberculosis hospital in rural Guatemala

    E-Print Network [OSTI]

    2014-01-01

    12. WHO. Tuberculosis profile for Guatemala. In: AssistanceMoHaS, editor. GuatemalaCity, Guatemala. 2011. https://extranet.who.int/ sree/

  15. Unthinkable Rebellion and the Praxis of the Possible: Ch'orti' Campesin@ Struggles in Guatemala's Eastern Highlands

    E-Print Network [OSTI]

    Casolo, Jennifer Jean

    2011-01-01

    y Chiquimula (PROZACHI), Guatemala. Paper presented at theCojtí Cuxil, D. (1997). El Movimiento Maya (en Guatemala).Guatemala City: Editorial Cholsamaj. Connelly, M. P. , Li,

  16. The Obsidian Blade Sequence at El Ujuxte, a Late Preclassic Site on the South Coast of Guatemala

    E-Print Network [OSTI]

    Nance, C. Roger; de Leeuw, Jan

    2005-01-01

    Industries of Pacific Guatemala and El Salvador: The PacificSociety in Pacific Guatemala: Settlements and Chronologyof the Río Naranjo, Guatemala. Papers of the New World

  17. Impact of reduced maternal exposures to wood smoke from an introduced chimney stove on newborn birth weight in rural Guatemala

    E-Print Network [OSTI]

    2011-01-01

    contributors in Guatemala: B. Arana, the Guatemalan Ministryduring pregnancy in rural Guatemala. Environ Health Perspecthouseholds of highland Guatemala. Environ Sci Technol 35(

  18. Youth Sexual Risk-Taking in Latin America: Implications for Public Health and Policy in Mexico, Belize, and Guatemala

    E-Print Network [OSTI]

    Dunning, Denise Raquel

    2012-01-01

    from Chile, Barbados, Guatemala, and Mexico, Studies inpdf10/10wpds_eng.pdf UNICEF. At A Glance: Guatemala.www.unicef.org/infobycountry/guatemala_statistics.html

  19. Youth Sexual Risk-Taking in Latin America: Implications for Public Health and Policy in Mexico, Belize, and Guatemala

    E-Print Network [OSTI]

    Dunning, Denise Raquel

    2012-01-01

    evidence from Chile, Barbados, Guatemala, and Mexico,evidence from Chile, Barbados, Guatemala, and Mexico,evidence from Chile, Barbados, Guatemala, and Mexico,

  20. Atmospheric lead in downtown Guatemala City

    SciTech Connect (OSTI)

    Durando, M.L.; Aragon, S.R.

    1982-01-01

    Atomic absorption (AA) analysis was employed to determine, for the first time in this country, lead concentrations in aerosols collected in Nuclepore filter media during the months of February and March (1980) in Guatemala City, Guatemala. In particular, the lead in the atmospheric fine particulate was measured in different downtown locations around noontime and in a single location at 1-h intervals throughout the day. The first was used to study short-term variations from one location to the other, and the second one was used to correlate parameters such as traffic density and wind velocity with the levels of airborne lead on the same day. In addition, this paper presents a brief discussion of the lead content in Guatemalan gasoline, the lead levels in street dusts, and the total suspended particulate matter in downtown Guatemala City.

  1. FALLOW MANAGEMENT PRACTICES IN GUATEMALA'S WESTERN HIGHLANDS: SOCIAL DRIVERS AND BIOPHYSICAL IMPACTSy

    E-Print Network [OSTI]

    FALLOW MANAGEMENT PRACTICES IN GUATEMALA'S WESTERN HIGHLANDS: SOCIAL DRIVERS AND BIOPHYSICAL practices in the Western Highlands of Guatemala based on interdisciplinary data collected using fertility; Buddleia skutchii; Baccharis vaccinioides; Andisol; Guatemala INTRODUCTION At any given time

  2. Risk of sexually transmitted infections among Mayan women in rural Guatemala whose partners are migrant workers

    E-Print Network [OSTI]

    Ikeda, JM; Schaffer, JR; Ixcot, MLS; Page, K; Hearst, N

    2014-01-01

    aids/ Countries/lac/guatemala_profile.pdf (2010). AccessedHIV and AIDS study among Mayan populations in Guatemala.Guatemala City: National HIV/AIDS program and UN Population

  3. Climate drying and associated forest decline in the lowlands of northern Guatemala during the late Holocene

    E-Print Network [OSTI]

    Gilli, Adrian

    Climate drying and associated forest decline in the lowlands of northern Guatemala during the late 2008 Keywords: Guatemala Holocene Lake sediments Environmental changes Tropical palaeoclimate of northern Guatemala. The question remains as to whether this vegetation change was driven exclusively

  4. Dancing in the Altiplano : K'iche' Maya culture in motion in contemporary highland Guatemala

    E-Print Network [OSTI]

    Taube, Rhonda Beth

    2009-01-01

    estructura social del valle de Guatemala en el siglo XVI. InEncuesta Sobre La Cultura de Los Ladinos en Guatemala. Vol.Social Guatemalteca. Guatemala: Editorial del Ministerio de

  5. The Role of Ethnicity in Father Absence and Children’s School Enrollment in Guatemala

    E-Print Network [OSTI]

    Ishida, Kanako

    2010-01-01

    de los mayas de ciudad de Guatemala. In M. Gonza lez de lade la Mujer K’iche’. Guatemala: IDESAC. Carson, M. (2006).la Elite de Poder en Guatemala. In A. Bianch, C. R. Hale, &

  6. Satellites and Senses of Place: Remote Monitoring of Guatemala's Maya Biosphere Reserve

    E-Print Network [OSTI]

    Rahder, Micha

    2014-01-01

    Freedom House 2012 Guatemala. http://www.freedomhouse.org/and M. Cristina 2004 Lynching in Guatemala Legacy of War andMaya Forest of Belize, Guatemala, and Mexico. Pp. 111–124.

  7. Granados-Dieseldorff, Christensen, Kihn-Pineda -Ichthyofauna of Lachu Lake, Alta Verapaz, Guatemala Granados-Dieseldorff, Christensen, Kihn-Pineda -Ichthyofauna of Lachu Lake, Alta Verapaz, Guatemala

    E-Print Network [OSTI]

    , Guatemala © Granados-Dieseldorff, Christensen, Kihn-Pineda - Ichthyofauna of Lachuá Lake, Alta Verapaz, Guatemala 1 PHOTO ALBUM Ichthyofauna of Lachuá Lake, Alta Verapaz, Guatemala Examples of the Ichthyofauna of Lachuá Lake, Alta Verapaz, Guatemala (Granados-Dieseldorff 2001 and Granados-Dieseldorff et al 2012

  8. The effects of migrant remittances on population–environment dynamics in migrant origin areas: international migration, fertility, and consumption in highland Guatemala

    E-Print Network [OSTI]

    Davis, Jason; Lopez-Carr, David

    2010-01-01

    in fertility patterns in Guatemala. Population, Space andRemittances and poverty in Guatemala. World Bank Policythe Maya Biosphere Reserve, Guatemala. Human Ecology, 36(2),

  9. The impacts of sex work regulations and implementation of immigration policies on Central American sex workers' safety and health along the Mexico-Guatemala border

    E-Print Network [OSTI]

    Rocha Jiménez, Teresita

    de Límites y Aguas entre México y Guatemala. (2000).Terrestre entre México y Guatemala tiene una extensión totaldiplomatico_especial/guatemala_comision _ limites_aguas.pdf

  10. The magmatic plumbing system beneath Santiaguito Volcano, Guatemala Jeannie A.J. Scott a,

    E-Print Network [OSTI]

    Rose, William I.

    The magmatic plumbing system beneath Santiaguito Volcano, Guatemala Jeannie A.J. Scott a, , Tamsin, Guatemala City, Guatemala a b s t r a c ta r t i c l e i n f o Article history: Received 9 September 2011 storage Ascent path The silicic dome complex of Santiaguito, Guatemala, has exhibited continuous extrusive

  11. The Marriage Core of the Elite Network of Colonial Guatemala Narda Alcntara Valverde*

    E-Print Network [OSTI]

    White, Douglas R.

    The Marriage Core of the Elite Network of Colonial Guatemala Narda Alcántara Valverde* Silvia of Colonial Guatemala 1 The Marriage Core of the Elite Network of Colonial Guatemala1 Abstract The problem the core of the elite network of colonial Guatemala in the period 1640 and 1820 in structural terms

  12. SO2 emissions to the atmosphere from active volcanoes in Guatemala and El Salvador, 19992002

    E-Print Network [OSTI]

    Rose, William I.

    SO2 emissions to the atmosphere from active volcanoes in Guatemala and El Salvador, 1999 INSIVUMEH, 7a Avenida 14-57 Zona 13, Ciudad de Guatemala, Guatemala, Central America c Servicio Nacional de-based and aircraft correlation spectrometer (COSPEC) measurements at the principal active volcanoes in Guatemala

  13. Tomato chocolate spot virus, a member of a new torradovirus species that causes a necrosis-associated disease of tomato in Guatemala

    E-Print Network [OSTI]

    Batuman, O.; Kuo, Y.-W.; Palmieri, M.; Rojas, M. R.; Gilbertson, R. L.

    2010-01-01

    disease of tomato in Guatemala O. Batuman • Y. -W. Kuo • M.Abstract Tomatoes in Guatemala have been affected by a newUniversity of Valle de Guatemala, Guatemala City, Republic

  14. (Solar energy technology transfer, Guatemala City, Guatemala and Tegucigalpa, Honduras, August 20--August 30, 1989)

    SciTech Connect (OSTI)

    Waddle, D.B.

    1989-09-05

    I travelled to Guatemala City, Guatemala and to Tegucigalpa, Honduras to gather information regarding the possibility of transferring photovoltaic technology for rural household uses in each respective country. Meetings were held with US government officials in each country mission (USAID and the commercial attaches); with utility officials; cooperative managers; and PVO's. The overall response was very positive; two of the electric utilities interviewed would like to begin program design immediately. A coffee cooperative with 38,000 members also expressed a keen interest in putting into place a program similar to the photovoltaic household energy program established in the Dominican Republic. The purpose of the trip was to establish lines of communication with perspective project cooperators; that objective was accomplished.

  15. Festival Report: II Taller Centroamericano y del Caribe: Guatemala

    E-Print Network [OSTI]

    Bravo-Elizondo, Pedro

    1991-10-01

    Ricardo 152 LATIN AMERICAN THEATRE REVIEW Mendoza, salvadoreño radicado en Costa Rica; Maquillaje, por Damián Félix, panameño y finalmente Danza Teatro por María Méndez quien trabaja en Grecia, pero está de asueto en Guatemala. Hubo diferentes paneles...

  16. (Survey of three isolated diesel power stations in Guatemala)

    SciTech Connect (OSTI)

    Chronowski, R.A.

    1990-03-15

    I traveled to Guatemala City, Guatemala to participate with a team of specialists to study the operating, administrative, and management efficiency of isolated diesel power plants, operated by Instituto Nacional de Electrificacion (INDE). The study is part of a global initiative managed jointly by the Agency for International Development and the World Bank. The power plants were audited, including INDE's largest isolated diesel station, and two much smaller municipal and privately owned stations. I returned to the USA on February 20, 1990.

  17. The Effects of Migrant Remittances on Consumption in Highland Guatemala Jason Davis

    E-Print Network [OSTI]

    Lopez-Carr, David

    The Effects of Migrant Remittances on Consumption in Highland Guatemala Jason Davis DavidL. Carr This paper investigates the potential impact of migrant remittances on consumption in highland Guatemala

  18. BLDG. 80 (SU), RM. 106 561.297.1208 WWW.FAU.EDU/GOABROAD Guatemala Chapines

    E-Print Network [OSTI]

    Fernandez, Eduardo

    BLDG. 80 (SU), RM. 106 · 561.297.1208 · WWW.FAU.EDU/GOABROAD Guatemala Chapines Rising Tides of Lake Atitlan Antigua, Guatemala AAnnttiigguuaa,, GGuuaatteemmaallaa SSpprriinngg TTeerrmm Program 1 will benefit from an immersion into the rich culture of Guatemala and have opportunities to study medical

  19. Der Beitrag der deutschen Entwicklungszusammenarbeit zur Entschrfung der Flchtlings-und Migrationsproblematik: Die Fallstudie Guatemala

    E-Print Network [OSTI]

    Franz, Sven Oliver

    Migrationsproblematik: Die Fallstudie Guatemala Inaugural-Dissertation zur Erlangung der Doktorwürde der Philosophischen migración es un delito."1 (Schriftzug an der Tür einer Hütte in einem Dorf Guatemalas) ,,Es gibt kein................................................................................. 44 3 Die Fallstudie Guatemala: Die Fluchtfolgen im Aufnahmeland Mexiko und die Reintegration

  20. Carbon stocks in coffee agroforests and mixed dry tropical forests in the western highlands of Guatemala

    E-Print Network [OSTI]

    Evans, Tom

    of Guatemala Mikaela Schmitt-Harsh · Tom P. Evans · Edwin Castellanos · J. C. Randolph Received: 4 January 2012- ducted in 2007 and 2010 in the Lake Atitla´n region of Guatemala, this research examines the carbon pools Estudios Ambientales y de Biodiversidad, Universidad del Valle de Guatemala, 18 Avenida 11-95 Zona 15

  1. Frederico G. Antilln-Klussman Medical Director, Unidad Nacional de Oncologia Pediatrica, Guatemala

    E-Print Network [OSTI]

    Brent, Roger

    Frederico G. Antillón-Klussman Medical Director, Unidad Nacional de Oncologia Pediatrica, Guatemala, Pediatrica in Guatelmala. He obtained his Medical Doctor from the Universidad Francisco Marroquín, Guatemala of a treatment program for pediatric cancer in Guatemala. Dr. Antillon is a founder of the Association

  2. Land Tenure and Land Administration Issues in Guatemala Danielle Kelly Donovan

    E-Print Network [OSTI]

    Onsrud, Harlan J.

    Land Tenure and Land Administration Issues in Guatemala Danielle Kelly Donovan danielle.donovan@spatial.maine.edu May 2002 1. Abstract The evolution of land tenure in Guatemala is a mix of the native Mayan implementation stage, when the CIA began "Operation Success". The operation sent mercenaries into Guatemala

  3. (To discuss the dissemination of improved energy-efficient cookstoves in Guatemala, Guatemala City, Guatemala, June 5--7, 1989): Foreign trip report

    SciTech Connect (OSTI)

    Brown, M.A.

    1989-06-12

    Oak Ridge National Laboratory (ORNL) has a subcontract with Meso American Study Center on Appropriate Technology (CEMAT) to undertake a technology transfer project involving improved energy-efficient cookstoves in Guatemala. Meetings were held with Mr. Edgardo Caceres, Executive Director of CEMAT; with members of his staff; and CEMAT's subcontractor, Merca Plan, in order to assess the project's progress.

  4. Guatemala accelerates efforts to attract foreign E and D capital

    SciTech Connect (OSTI)

    NONE

    1997-01-20

    The Guatemalan government, headed by recently elected President Alvaro Arzu, has embarked on an ambitious program of petroleum exploration and development with the goal of producing 40,000 b/d by 2000. Production averaged 16,000 b/d last fall and was to be raised to 25,000 b/d by year end 1996. Oil and gas exploration began in Guatemala in the 1920s, but production is currently limited to two regions in the Peten basin in northeastern Guatemala. Officials at the Ministry of Energy and Mines aim to encourage comprehensive evaluation of the Peten basin as well as exploration of the Amatique basin in southeastern Guatemala and the Pacific basin on the country`s Pacific coast. The paper describes the Peten basin, the Amatique basin, the Pacific basin, bidding, and contract rules.

  5. An overview of the poultry industry of Guatemala 

    E-Print Network [OSTI]

    Braly Lopez, Esther Yvette

    1989-01-01

    was separated from his wife for three months while she was doing her research in Guatemala. hank you for encouraging me both psychologically and financially to finish my degree. I also appreciate the translations you did for me and the advice you gave. Your.... Rajan, yo r sense of humor and entertaining teaching style brought a bit of sunshine to my life when I really needed it. Special thanks goes to my in-laws in Guatemala: Sama Adriana Valdes, Papa Lionel Lopez?Byron and Carla Urrutia, Adrianita Lopez...

  6. New Guatemala law tries to attract new explorers

    SciTech Connect (OSTI)

    Not Available

    1984-02-01

    With only 6,280 bopd of production and reserves of only 13 million barrels, Guatemala's 25,200 bpd thirst has forced the country to rewrite its petroleum law. Among pluses in the new law are full-cost recovery and prices based on world levels. However, the stiff royalty and no provision for neutral arbitration are significant minuses.

  7. El teatro de los ochenta en Guatemala

    E-Print Network [OSTI]

    Carrillo, Hugo

    1992-04-01

    durante varios años de esta década se dedicó a presentar estrellas de la televisión internacional en comedias ligeras cobrando hasta Q100.00 por boleto. En 1990 se quemó y actualmente está en reparación. Nunca ha presentado artistas nacionales... durante varios años de esta década se dedicó a presentar estrellas de la televisión internacional en comedias ligeras cobrando hasta Q100.00 por boleto. En 1990 se quemó y actualmente está en reparación. Nunca ha presentado artistas nacionales...

  8. Lake Petn Itz, a 165 m deep lake in northern Guatemala, is the deepest lake in the lowlands of

    E-Print Network [OSTI]

    Gilli, Adrian

    Lake Petén Itzá, a 165 m deep lake in northern Guatemala, is the deepest lake in the lowlands. The cores were shipped from Guatemala in a refrigerated container and arrived safely at the National

  9. Unthinkable Rebellion and the Praxis of the Possible: Ch'orti' Campesin@ Struggles in Guatemala's Eastern Highlands

    E-Print Network [OSTI]

    Casolo, Jennifer Jean

    2011-01-01

    Santiago de Guatemala to the sparsely populated eastern countryside, especially along the Motagua riverSantiago de Guatemala, to the sparsely populated eastern countryside, especially along the Motagua River.

  10. Nutritional Assessment of the Elderly of San Pedro Ayampuc, Guatemala: Evaluation of Anthropometry, Biochemistry, and Helminthic Infection

    E-Print Network [OSTI]

    King, Jane E

    1991-01-01

    Guatemala: Evaluation of Anthropometry, Biochemistry, andMETHODS Census Anthropometry Blood samples/BiochemistryCensus . . . . . . . . .Anthropometry Biochemical values

  11. Relying on years of ethnographic research in highland Guatemala, this qualitative study explores domestic and family violence in a Maya

    E-Print Network [OSTI]

    Abstract Relying on years of ethnographic research in highland Guatemala, this qualitative study conducted with most living members of an extended family in two departments of western Guatemala, and ten and Research. She has conducted extensive research with Mayan peoples in Guatemala, exploring issues related

  12. Colonization, clear-cutting, and cornfields: Rural migration and deforestation in The Sierra de Lacandn National Park, Petn, Guatemala

    E-Print Network [OSTI]

    Lopez-Carr, David

    Lacandón National Park, Petén, Guatemala David L. Carr University of North Carolina at Chapel Hill. The research site is a settlement frontier within a protected area in northern Guatemala. The great expanse-poor colonists from other rural areas in Guatemala. Colonists arrived following the construction of a road

  13. Metamorphic reworking of a high pressurelow temperature mlange along the Motagua fault, Guatemala: A record of Neocomian and Maastrichtian

    E-Print Network [OSTI]

    Hemming, Sidney R

    Metamorphic reworking of a high pressure­low temperature mélange along the Motagua fault, Guatemala processes oblique collisional tectonics The Guatemala suture zone is a major east­west left-lateral strike slip boundary that separates the North American and Caribbean plates in Guatemala. The Motagua fault

  14. 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 Thomas M. Whitmore.) This dissertation explores the primary proximate and underlying causes

  15. Migration to the Maya Biosphere Reserve, Guatemala: Why place matters David L. Carr

    E-Print Network [OSTI]

    Lopez-Carr, David

    1 Migration to the Maya Biosphere Reserve, Guatemala: Why place matters David L. Carr Assistant-4060 Paper submitted to Human Organization Please do not cite without permission of the author Migration to the Maya Biosphere Reserve, Guatemala: Why place matters Abstract Virtually all migration research examines

  16. Transverse extension of Guatemala active margin: implications for accretion

    SciTech Connect (OSTI)

    McMillen, K.J.

    1987-05-01

    The inner trench wall of the Middle America Trench off Guatemala does not show evidence of accretion, based on DSDP Legs 67 and 84. The presence of normal faults on the lower inner trench slope has resulted in various subsidence models for the margin. Fault traces would be expected to trend parallel to the margin (northwest-southeast) if margin subsidence had occurred. Instead, the faults trend north-south and occur in groups of faults downdropped to the east and to the west. The faults do not seem to be related to margin subsidence but rather to previously proposed Cenozoic Central American rifting. The rifting resulted from crustal bending as the Central American block rounded southern Mexico during differential North American/Caribbean plate motion. The rifts, which extend nearly to the trench axis, underlie the San Jose submarine canyon and align with the Guatemala City graben. Possible east-west accommodation zones, between fault zones that dip in opposite directions, exist near the shelf edge. These accommodation zones may have formed along lines of weakness where oceanic crust was previously emplaced into the margin during or prior to the Eocene. These rifts show that compressional and extension features can occur simultaneously with underthrusting on active margins.

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

    E-Print Network [OSTI]

    Burton, Michael Cassidy

    2013-02-22

    . The objective of this research is to show how the interaction between the United States and Guatemala during President Arbenz's tenure in power is a good example of Edleman's political spectacle. Depending on how US policymakers interpreted Arbenz's policy...

  18. Sumatran rice and miracle herbs: Local and international natural knowledge in late-colonial Guatemala

    E-Print Network [OSTI]

    Brockmann, Sophie

    2014-01-01

    themselves to bringing ‘Enlightenment’ and ‘improvement’ to the region through natural history and other ‘useful arts’. Articles published in the Economic Society’s newspaper, the Gazeta de Guatemala, show that a socially and geographically wider network...

  19. The macroeconomic module of the Energy Policy Evaluation Model of Guatemala

    SciTech Connect (OSTI)

    Booth, S.R. (Los Alamos National Lab., NM (USA)); Cancino, R. (Direccion General de Planificacion y Desarrollo Energetico, Guatemala City (Guatemala))

    1991-08-01

    This report describes the methodology and results of the macroeconomic module of the Energy Policy Evaluation Model of Guatemala (MEPEG). This effort was conducted jointly by the Ministry of Energy and Mines of Guatemala and Los Alamos National Laboratory under the Central American Energy and Resources Project of Los Alamos, funded by the US Agency for International Development. The data, theory, empirical specification, and simulation results of the macroeconomic module are described. 10 refs., 2 figs., 6 tabs.

  20. Electrical power systems (Guatemala). Electric power generation and distribution equipment, March 1991. Export trade information

    SciTech Connect (OSTI)

    Not Available

    1991-03-01

    The article analyzes the electrical power generation and distribution equipment market in Guatemala and contains the following subtopics: market assessment, competitive situation, market access, trade promotion opportunities, best sales prospects, and statistical data. The total market demand of electrical power generation and distribution equipment and materials in Guatemala increased from US $19.0 million in 1987 to $24.8 million in 1988 (30.5 percent).

  1. Frictional characteristics of serpentinite from the Motagua fault zone in Guatemala: an experimental study 

    E-Print Network [OSTI]

    Dengo, Carlos Arturo

    1978-01-01

    , suggestions, and criticisms, all of which in proved the content: of this thesis. !!ith much pleasure I thank the patient guidance and conversations provided by my Father, Dr. Gabriel Dengo (ICAITI, Guatemala!. He in- traduced me to the many problems...-Textured Serpentinites Compositions of Serpentinite Summary of Implications of Serpentinite to the Ear th- quake Problem . 58 78 LIST OF FIGURES FIGURE PAGE Location map showing the serpentinite outcrops in Guatemala (in black) and the major st. rike...

  2. Guatemala switch to crude saves over $1 million a month

    SciTech Connect (OSTI)

    de Biasi, V.

    1980-03-01

    In a two-step program designed to reduce fuel costs and improve operating efficiency, Empresa Electrica de Guatemala has modified two General Electric PG 5341 gas turbines at Laguna to run on crude oil and installed heat recovery equipment for repowering two existing steam turbines. The gas turbines, nominally rated at around 19,000 kW for base load operation at 70/sup 0/F average ambient temperature and 4000 feet altitude, were installed in 1977-78 as a base load backup to hydro power during the dry season. Original plan was to put them into immediate service as simple cycle units and then convert to combined cycle operation. Priorities were shifted to switch over from distillate to crude oil firing before going ahead with the combined cycle istallation. Their economic evaluation showed the initial investment would be paid off in a few months by the savings in fuel costs.

  3. 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

    2011-04-21

    youth in Guatemala participate in the program together. In this comparative analysis of Kaqchikel Maya young women and non–indigenous young women in Guatemala, a written anonymous survey was administered to both groups of female participants to determine...

  4. The effects of migrant remittances on population–environment dynamics in migrant origin areas: international migration, fertility, and consumption in highland Guatemala

    E-Print Network [OSTI]

    Davis, Jason; Lopez-Carr, David

    2010-01-01

    Guatemala-to-US migration, total primary energy consumptionwas the primary motivation for most US migration (Table 4).

  5. FABI WORK IN NATIVE PINE FORESTS IN GUATEMALA Project title: Understanding pest and pathogen threats to pine under expanding global cultivation

    E-Print Network [OSTI]

    FABI WORK IN NATIVE PINE FORESTS IN GUATEMALA Project title: Understanding pest and pathogen on common pine species in Guatemala, particularly those under testing as hybrid partners with Pinus patula, the University of San Carlos and the private forestry sector in Guatemala to discuss the project and avenues

  6. 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 Guatemala compte des aires protégées depuis 1955. Sa loi sur les aires protégées a été votée en 1989, et sa

  7. Measuring large topographic change with InSAR: Lava thicknesses, extrusion rate and subsidence rate at Santiaguito volcano, Guatemala

    E-Print Network [OSTI]

    Elliott, John

    at Santiaguito volcano, Guatemala S.K. Ebmeier a,n , J. Biggs b , T.A. Mather a , J.R. Elliott a , G. Wadge c , F. We apply this to Santiaguito volcano, Guatemala, and measure increases in lava thickness of up to 140

  8. (Energy efficiency improvement studies for Costa Rica and Guatemala)

    SciTech Connect (OSTI)

    Waddle, D.B.

    1990-05-30

    I travelled to San Jose, Cost Rica, on May 20, 1990 to report on the progress of the Integrated Power Sector Efficiency Analysis Project to the Instituto Costarrincense de Electricidad, and to USAID/San Jose. I also discussed the progress and plans for the CONELECTRICAS Small Hydroelectric Project supported by ORNL through the Renewable Energy Applications and Training Project. Both projects are proceeding on schedule. ORNL will complete further supply side analysis after comments are submitted by ICE, with respect to the information provided on this visit. The CONELECTRICAS project will require further ORNL input to assist in optimization of equipment selection and to perform the required financial and economic cost analyses. I travelled to Guatemala City on May 22, 1990. I met with Instituto Nacional de Electricacion (INDE) to discuss the findings and recommendations of the Electric Power Utility Efficiency Improvement Study undertaken in February, 1990. I also met with Mario Funes to discuss future ORNL assistance to ROCAP in support of the CARES project as well as other ROCAP energy initiatives.

  9. Hydrogeochemical exploration of the Tecuamburro Volcano region, Guatemala

    SciTech Connect (OSTI)

    Goff, F.; Truesdell, A.H.; Janik, C.J.; Adams, A.; Roldan-M, A.; Meeker, K. (Los Alamos National Lab., NM (USA); Geological Survey, Menlo Park, CA (USA); Los Alamos National Lab., NM (USA); Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico; Los Alamos National Lab., NM (USA))

    1989-01-01

    Approximately 100 thermal and nonthermal water samples and 20 gas samples from springs and fumaroles have been chemically and isotopically analyzed to help evaluate the geothermal potential of the Tecuamburro Volcano region, Guatemala. Thermal waters of the acid- sulfate, steam condensate, and neutral-chloride types generally occur in restricted hydrogeologic areas: Tecuamburro-Laguna Ixpaco (acid- sulfate); andesite highland north of Tecuamburro (steam-condensate); Rio Los Esclavos (neutral-chloride). One small area of neutral-chloride springs east of the village of Los Esclavos has no relation to the Tecuamburro geothermal system. Neutral-chloride springs on the Rio Los Esclavos east and southeast of Tecuamburro show mixing with various types of groundwaters and display a maximum oxygen-18 enrichment compared to the world meteoric line of only about 1.5 parts per thousand. Maximum estimated subsurface temperatures are {le}200{degree}C. In contrast, maximum estimated subsurface temperatures based on gas compositions in the Laguna Ixpaco area are about 300{degree}C. The relation of neutral-chloride waters to the overall Tecuamburro geothermal system is not entirely resolved but we have suggested two system models. Regardless of model, we believe that a first exploration drill hole should be sited within 0.5 km of Laguna Ixpaco to tap the main geothermal reservoir or its adjacent, main upflow zone. 9 refs., 4 figs., 3 tabs.

  10. Characteristics of the Zunil Geothermal Field (Western Guatemala)

    SciTech Connect (OSTI)

    Bethancourt, H.R.; Dominco, E.

    1982-10-01

    The Zunil geothermal field represents the marginal, shallow expression of a vast geothermal complex buried beneath active volcanic edifices (Cerro Quemado, Volcan Santa Maria, Western Guatemala) some kilometers to the west. The area lies at the edge of a tecto-volcanic depression where some 1,000 m of Tertiary and Quaternary volcanics are underlain by a granodioritic basement. High temperature geothermal fluids (over 280/sup 0/C) reach the field from the west, upflowing along the inclined contact between the granodioritic and the overlying volcanics, and along fractures in the basement itself. A conglomeratic layer at the volcanics/basement contact, and the underlying weathered cap of the basement form the only permeable horizon of the succession; this horizon forms the local reservoir tapped by the productive wells. Its reduced thickness (around 50 m) allows for a limited fluid storage such that field production relies on external recharge along the permeable horizon and underlying fractures in the granodiorite. Production testing and simulation models indicate a fairly rapid evolution of reservoir conditions from the liquid to the steam phase, due to pressure drawdown, in its turn due to a restricted inflow. The phenomenon determines an upgrading of the fluid enthalpy, but a decline of mass output. Simulated reinjection into the reservoir proved to be an effective measure to slow down such an evolution and optimize the field exploitation.

  11. Studies of geothermal power and process heat applications in St. Lucia and Guatemala

    SciTech Connect (OSTI)

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

    1986-01-01

    Many countries have the potential to use geothermal energy for both power production and process heat applications. Two Los Alamos programs have studied the most effective use of geothermal energy in St. Lucia and Guatemala. The general objectives are (1) to reduce oil imports; (2) develop employment opportunities; and (3) make products more competitive. The initial St. Lucia studies emphasized power generation but a number of applications for the power plant's residual heat were also found and costs and systems have been determined. The costs of geothermal heat compare favorably with heat from other sources such as oil. In Guatemala, the development of the nation's first geothermal field is well advanced. Process heat applications and their coordination with power generation plants are being studied at Los Alamos. Guatemala has at least two fields that appear suitable for power and heat production. These fields are close to urban centers and to many potential heat applications.

  12. Petroleum geology and resources of southeastern Mexico, northern Guatemala, and Belize

    SciTech Connect (OSTI)

    Peterson, J.A.

    1986-05-01

    Petroleum deposits in southeastern Mexico and Guatemala occur in two main basinal provinces: the Gulf Coast Tertiary basin area, which includes the Reforma and offshore Campeche Mesozoic fields, and the Peten basin of eastern Chiapas State (Mexico) and Guatemala. Major oil production, in order of importance, is from Cretaceous, Paleocene, and Jurassic carbonate reservoirs in the reforma and offshore Campeche area. Several small oil fields have been discovered in Cretaceous carbonate reservoirs in west-central Guatemala. Almost all important production is in salt structure traps or on domes and anticlines that may be related to deep-seated salt movement. Some minor oil production has occurred in Cretaceous carbonate reservoirs in a buried overthrust belt along the west flank of the Veracruz basin. Gas production is mainly from Tertiary sandstone reservoirs.

  13. Capture of Anastrepha species (Diptera: Tephritidae) with multilure traps and biolure attractants in Guatemala

    SciTech Connect (OSTI)

    Martinez, A.J.; Salinas, E.J. [USDA-APHIS-PPQ-CPHST, 22675 N. Moorefield Rd, Edinburg, TX 78541-5033 (United States); Rendon, P. [USDA-APHIS-PPQ-CPHST, 4a Avenida 12-62, Zona 10, Guatemala City (Guatemala)

    2007-03-15

    Two trapping systems were compared in a study in Guatemala during the wet season, May through Dec 2001. Trap/lure combinations consisting of green or yellow-based plastic McPhail-like traps baited with a synthetic 2-component lure (putrescine and ammonium acetate) and 300 mL of propylene glycol antifreeze as a preservative were compared to the traditional glass McPhail baited with torula yeast/borax and 300 mL of water. Both systems captured several key Anastrepha species including Anastrepha ludens Loew, A. obliqua, Macquart, A. serpentina Weidemann, A. striata Schiner, A. distincta Greene, A. fraterculus Weidemann as well as Ceratitis capitata Weidemann. Additionally, 13 other Anastrepha spp. were captured with the synthetic lure. The plastic traps captured more key flies than the McPhail trap except for A. distincta where there were no significant differences between the yellow-based plastic trap and the McPhail trap and no significant differences between any trap and lure for trapping A. fraterculus. The synthetic lure lasted 10 weeks. The sex ratio was female-biased for almost all captured key species in both systems. Moreover, there were significant numbers of captured nontarget insects in all traps; however, the captured flies in those traps with the synthetic lure were not adversely affected by these insects. Propylene glycol-based antifreeze was a superior preservative when compared to borax/water. (author) [Spanish] En Guatemala, se compararon dos sistemas de trampeo durante la epoca lluviosa de Mayo a Deciembre, 2001. Combinaciones de trampa/atrayente que consistieron de trampas de plastico con bases verdes o amarillos y con atrayentes sinteticos (acetate de amoniaco y putrecina) fueron comparadas con el sistema de trampeo tradicional McPhail de vidrio cebada con torula y borax en agua. Los dos sistemas capturaron moscas del genero Anastrepha incluyendo Anastrepha ludens Loew, A. obliqua, Macquart, A. serpentina Weidemann, A. striata Schiner, A. distincta Greene, A. fraterculus Weidemann y Ceratitis capitata Weidemann. Ademas, se capturaron 13 especias adicionales de Anastrepha asi como Toxotrypana curvicauda Gerstaecker con el cebo sintetico. El cebo sintetico fue efectivo por diez semanas sin recebar. Las trampas de plastico capturaron mas moscas del genero Anastrepha que la trampa de cristal McPhail. Las excepciones fueron A. distincta en donde no hubo differencias el la captura con la trampa de plastico con base amarillo y la trampa McPhail de cristal asi como A. fraterculus en donde no hubo differencias comparando la captura de moscas con ambos sistemas. La proporcion sexual de las moscas capturadas con los dos sistemas fue al favor de las hembras. La captura de otros tipos de insectos fue significantemente elevado, sin embargo, las moscas capturadas con los cebos sinteticos no fueron afectados adversamente por estos insectos. El 10% del anticongelante, glicol propilico, fue superior al borax/agua como conservador de las moscas capturardas. (author)

  14. Electrical power systems (Guatemala). Non-current carriers, March 1991. Export trade information

    SciTech Connect (OSTI)

    Not Available

    1991-03-02

    The article analyzes the non-current carrying devices market in Guatemala and contains the following subtopics: market assessment, competitive situation, market access, trade promotion opportunities, best sales prospects, and statistical data. The market for noncurrent-carrying devices in Guatemala totalled US $4.3 million in 1988, compared with a total of US $5.0 million in 1989. Approximately US $6.4 million is expected in 1990. Of this import market, the United States has always had the greatest share.

  15. Late Quaternary palaeoenvironment of northern Guatemala: evidence from deep drill cores and seismic stratigraphy of Lake

    E-Print Network [OSTI]

    Gilli, Adrian

    of an International Continental Scientific Drilling Program project. The sediment records from deep water consist, overlain by deep-water clays, suggest a lake level rise and subsequent stabilization at high stage. From caLate Quaternary palaeoenvironment of northern Guatemala: evidence from deep drill cores and seismic

  16. Land parcel fragmentation in the agricultural frontier: Sierra del Lacandn National Park, Guatemala

    E-Print Network [OSTI]

    Lopez-Carr, David

    , Guatemala Laurel K. Suter David L. Carr Department of Geography University of California, Santa Barbara are often viewed as the primary proximate agents of deforestation (Rudel and Roper 1996; Carr 2005). Although population growth is positively associated with agricultural expansion in Latin America (Carr

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

    SciTech Connect (OSTI)

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

    1988-08-01

    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.

  18. Assessing and Modeling Exposure to Indoor Air Pollution among Rural Women in Guatemala

    E-Print Network [OSTI]

    Assessing and Modeling Exposure to Indoor Air Pollution among Rural Women in Guatemala Lisa pollution in rural areas of developing countries. It is estimated that about half (53%) of all households in the poor countries of Latin American use biofuels (wood, dung and/or crop residues) to cook. Combustion by

  19. Instituto Nacional de Electrification, Guatemala Load Dispatch Center and Global Communications Center. Feasibility report (Instituto Nacional de Electrificacion, Guatemala Centro Nacional de Despacho de Carga y Sistema Global de Comunicaciones). Export trade information

    SciTech Connect (OSTI)

    Not Available

    1985-07-01

    The report presents the results of a feasibility study for the National Load Dispatch Center and Global Communications System Project in Guatemala. The project consists of a communication system which will provide Institute Nacional de Electrificacion (INDE) operations personnel direct voice access to all major power system facilities. In addition, a modern computer based load dispatch center has been configured on a secure and reliable basis to provide automatic generation control of all major interconnected generating plants within Guatemala.

  20. Trace element and technological analyses of obsidian artifacts from the Northern ridge of Lake Atitlan, Department of Solola, Guatemala 

    E-Print Network [OSTI]

    Woodward, Michelle Ruth

    1996-01-01

    One hundred obsidian artifacts from the San Jose Chacaya site area located along the northern ridge of Lake Atitlan, Guatemala were subjected to Neutron Activation Analysis (NAA) to determine their provenience. In addition, sixty-six samples from...

  1. "Health is a business for everyone and is not a right to anyone:" Neoliberal health care provision in rural Guatemala

    E-Print Network [OSTI]

    Fernandes da Cunha Loureiro Amorim, Clarice

    2012-08-31

    Guatemala caught the attention of the international community as it emerged from its civil war. The stabilization offered by the Peace Accords of 1996 allowed the World Bank and the Inter-American Development Bank to urge ...

  2. Written in invisible ink : a case study on the politics of free trade reform and labor regulation in Guatemala

    E-Print Network [OSTI]

    Pipkin, Seth Daniel

    2006-01-01

    This thesis makes two primary claims: first, that the US - Dominican Republic - Central America Free Trade Agreement (US-DR CAFTA, or CAFTA) has had important effects on labor regulation in Guatemala that are not contained ...

  3. The effects of migrant remittances on population–environment dynamics in migrant origin areas: international migration, fertility, and consumption in highland Guatemala

    E-Print Network [OSTI]

    Davis, Jason; Lopez-Carr, David

    2010-01-01

    family aintenance, and Mexico-US migration. Demographic2009). Compared with Mexico, migration between Guatemala andof migration on infant survival in Mexico. Demography, 36(

  4. Energy expenditure and socioeconomic status in Guatemala as measured by the doubly labelled water method

    SciTech Connect (OSTI)

    Stein, T.P.; Johnston, F.E.; Greiner, L.

    1988-02-01

    The energy expenditure of lower (group 1) and upper socioeconomic group females (group 2) from a marginal community in Guatemala City was determined by using the doubly labelled water method. Energy expenditure values were 1925 +/- 66 (mean, SEM) kcal/d (group 1) and 2253 +/- 145 kcal/d group 2 (p less than 0.03). About half of this difference can be attributed to size.

  5. Electrical power systems (Brazil, Chile, Colombia, Dominican Republic, Guatemala, Jamaica, Panama and Peru)

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    This 12-part set of reports contains market information on the following countries and topics: Brazil - potentiometers, steam turbines, gas turbines, electric generators; Chile - power systems; Colombia - electric generators; Dominican Republic - electric generators; Guatemala - power generation and distribution equipment, non-current carriers, electric generators, and turbines; Jamaica - power systems; Panama - power generation and control equipment; and Peru - power generation equipment. These reports have been processed separately for inclusion on the data base.

  6. Application of scientific core drilling to geothermal exploration: Platanares, Honduras and Tecuamburro Volcano, Guatemala, Central America

    SciTech Connect (OSTI)

    Goff, S.J.; Goff, F.E.; Heiken, G.H. [Los Alamos National Lab., NM (United States); Duffield, W.A. [Geological Survey, Flagstaff, AZ (United States); Janik, C.J. [Geological Survey, Menlo Park, CA (United States)

    1994-04-01

    Our efforts in Honduras and Guatemala were part of the Central America Energy Resource Project (CAERP) funded by the United States Agency for International Development (AID). Exploration core drilling operations at the Platanares, Honduras and Tecuamburro Volcano, Guatemala sites were part of a geothermal assessment for the national utility companies of these countries to locate and evaluate their geothermal resources for electrical power generation. In Honduras, country-wide assessment of all thermal areas determined that Platanares was the site with the greatest geothermal potential. In late 1986 to middle 1987, three slim core holes were drilled at Platanares to a maximum depth of 680 m and a maximum temperature of 165{degree}C. The objectives were to obtain information on the geothermal gradient, hydrothermal alterations, fracturing, and possible inflows of hydrothermal fluids. Two holes produced copious amounts of water under artesian conditions and a total of 8 MW(t) of energy. Geothermal investigations in Guatemala focused on the Tecuamburro Volcano geothermal site. The results of surface geological, volcanological, hydrogeochemical, and geophysical studies at Tecuamburro Volcano indicated a substantial shallow heat source. In early 1990 we drilled one core hole, TCB-1, to 808 m depth. The measured bottom hole temperature was 238{degree}C. Although the borehole did not flow, in-situ samples indicate the hole is completed in a vapor-zone above a probable 300{degree}C geothermal reservoir.

  7. An analysis of cattle-farming in the coffee producing area of the Pacific Slope in Guatemala 

    E-Print Network [OSTI]

    Cordon, Oscar Humberto

    1967-01-01

    AN ANALYSIS OF CATTLE-FARMING IN THE COFFEE PRODUCING AREA OF THE PACIFIC SLOPE IN GUATEMALA A Thesis By OSCAR HUMBERTO CORDON Submitted to the Graduate College of the Texas ASM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE January 1967 Ma]or Sub]ect: Animal Science AN ANALYSIS OF CATTLE-FARMING IN THE COFFEE PRODUCING AREA OF THE PACIFIC SLOPE IN GUATEMALA A Thesis By OSCAR HUMBERTO CORDON Approved as to style and content by: airman...

  8. Hydrogeochemical investigations in support of well logging operations at the Zunil geothermal field, Guatemala

    SciTech Connect (OSTI)

    Adams, A.; Golf, F.; Trujillo, P.E. Jr.; Counce, D.; Archuleta, J.; Dennis, B. (Los Alamos National Lab., NM (USA)); Medina, V. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

    1990-01-01

    A suite of 41 thermal and nonthermal waters in the Zunil-Quetzaltenango region, Guatemala, were collected as part of a well logging operation conducted by the Instituto Nacional de Electrificacion (INDE) and Los Alamos National Laboratory. Both in situ and weirbox samples were collected in the Zunil geothermal field. The various data suggest that the reservoir at Zunil is geochemically inhomogeneous. Stable isotope data suggest recharge to the field comes primarily from the north and east whereas tritium data indicate that the reservoir waters may be 500 to 7500 years old. 14 refs., 4 figs., 3 tabs.

  9. Population, Rural Development, and Land Use Among Settler Households in an Agricultural Frontier in Guatemala's Maya Biosphere Reserve

    E-Print Network [OSTI]

    Lopez-Carr, David

    in Guatemala's Maya Biosphere Reserve David Carr Ph.D. University of California, Santa Barbara carr increasingly occurs on impoverished soils (Carr, Barbieri et al., 2006). Agricultural frontier1 This paper). This is especially true in Latin America (Rudel & Roper 1996; Carr & Bilsborrow, 2001). Political, economic

  10. Tomato chocolate spot virus, a member of a new torradovirus species that causes a necrosis-associated disease of tomato in Guatemala

    E-Print Network [OSTI]

    Batuman, O.; Kuo, Y.-W.; Palmieri, M.; Rojas, M. R.; Gilbertson, R. L.

    2010-01-01

    Tomato chocolate spot virus, a member of a new torradovirusRepublic of Guatemala this virus being the causal agent oflate-spot-associated virus, revealed a genome composed of

  11. Electrical power systems (Guatemala). Small generators and turbines, March 1992. Export trade information

    SciTech Connect (OSTI)

    Not Available

    1992-03-01

    In Guatemala the market for all types of electrical power generator systems, including parts and accessories, increased from US $19.5 million in 1990 to US $25.5 in 1991 (up 30.7 percent). Guatemalan import statistics list within this category all types of turbines and hydraulic electric power generating engines, regardless of their size or power generating capacity. Also included in the study are all types of electrical generators that are moved or operated by an attached fuel powered engine. The outlook for future market demand for electrical power generating systems looks promising for the next three or four years, with an estimated average increase of 7.3 percent per year.

  12. The direct application of geothermal energy to provide process heat in Guatemala

    SciTech Connect (OSTI)

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

    1987-09-01

    One part of an energy and resource development program in Central America is a geothermal process heat project in Guatemala. The feasibility of the direct heat application depends upon the production characteristics and reliability of the geothermal source. Other factors are the distance from the heat source, quantity of use, and capacity factor of the use facilities. Favorable conditions would be distances of under 5 km, heat requirements approximately equal to the well capacity, and high capacity factors (say 60% or higher) in the industrial plants. Depending upon the values of these factors, energy costs of less than $1.00/million Btus to greater than $5.00/million Btus have been estimated. This can be compared to about $5.00/million Btus for petroleum-based fuels in Guatemala in mid 1987. A survey was made of existing industries in the Amatitlan and Zunil geothermal areas. In both Amatitlan and Zunil the existing industries are spread out over an area too large to be called an optimum. The most promising situation for an industrial park development is at Amatitlan, except that proven production wells are not yet available. At Zunil, production wells exist, but a diverse nearby industrial base does not. However, both of these two areas are sufficiently promising to merit further development. Consequently, a demonstration project is underway aimed at the ultimate establishment of an agricultural processing center at Zunil. This center would have the capability to process agricultural products by dehydration, freezing, and cold storage. 2 refs., 4 figs., 2 tabs.

  13. De de se

    E-Print Network [OSTI]

    Anand, Pranav

    2006-01-01

    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 ...

  14. C O L L E G E O F A RT S & S C I E N C EV A N D E R B I L T U N I V E R S I T Y n a remote jungle of Guatemala, Professor

    E-Print Network [OSTI]

    Wikswo, John

    of Guatemala, Professor Arthur Demarest and his team of Vanderbilt and Guatemalan archeologists have uncov in Guatemala (please see sidebar, page 4). The Cancuén research might cause scholars to revise their views

  15. Results of geothermal gradient core hole TCB-1, Tecuamburro volcano geothermal site, Guatemala, Central America

    SciTech Connect (OSTI)

    Adams, A.I.; Chipera, S.; Counce, D.; Gardner, J.; Goff, S.; Goff, F.; Heiken, G.; Laughlin, A.W.; Musgrave, J.; Trujillo, P.E. Jr. (Los Alamos National Lab., NM (United States)); Aycinena, S.; Martinelli, L. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O.; Revolorio, M.; Roldan, A. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion); D

    1992-02-01

    Results of geological, volcanological, hydrogeochemical, and geophysical field studies conducted in 1988 and 1989 at the Tecuamburro volcano geothermal site in Guatemala indicated that there is a substantial shallow heat source beneath the area of youngest volcanism. To obtain information on subsurface temperatures and temperature gradients, stratigraphy, hydrothermal alteration, fracturing, and possible inflows of hydrothermal fluids, a geothermal gradient core hole (TCB-1) was drilled to 808 m low on the northern flank of the Tecuamburro volcano Complex, 300 km south of a 300-m-diameter phreatic crater, Laguna Ixpaco, dated at 2,910 years. Gases from acid-sulfate springs near Laguna Ixpaco consistently yield maximum estimated subsurface temperatures of 250--300{degrees}C. The temperature versus depth curve from TCB-1 does not show isothermal conditions and the calculated thermal gradients from 500--800 m is 230{degrees}C/km. Bottom hole temperature is 238{degrees}C. Calculated heat flow values are nearly 9 heat flow units (HFU). The integration of results from the TCB-1 gradient core hole with results from field studies provides strong evidence that the Tecuamburro area holds great promise for containing a commercial geothermal resource.

  16. Tecuamburro Volcano, Guatemala geothermal gradient core hole drilling, operations, and preliminary results

    SciTech Connect (OSTI)

    Goff, S.; Heiken, G.; Goff, F.; Gardner, J. (Los Alamos National Lab., NM (USA)); Duffield, W. (Geological Survey, Flagstaff, AZ (USA)); Martinelli, L.; Aycinena, S. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

    1990-01-01

    A geothermal gradient core hole (TCB-1) was drilled to a depth of 700+ m at the Tecuamburro geothermal site, Guatemala during February and March, 1990. The core hole is located low on the northern flank of the Tecuamburro Volcano complex. Preliminary analysis of cores (>98% core recovery) indicates that the hydrothermal system may be centered in the 4-km-diameter Chupadero Crater, which has been proposed as the source of pyroxene pumice deposits in the Tecuamburro area. TCB-1 is located 300 m south of a 300-m-diameter phreatic crater, Laguna Ixpaco; the core hole penetrates the thin edge of a tuff ring surrounding Ixpaco and zones of hydrothermal brecciation within the upper 150 m may be related to the phreatic blast, dated at 2,910 {sup 14}C years. At the time of this writing, the unequilibrated temperature at a depth of 570m was 180{degree}C. Data on fracturing, permeability, hydrothermal alteration, and temperature will be presented. 3 refs., 3 figs.

  17. PHaSe-EFRC

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

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonforsupernovae model (JournalHearingsHuman CapitalOmega LaserPHaSe

  18. Petroleum geology of Pacific margin of Central America and northern South America, from Guatemala to Ecuador

    SciTech Connect (OSTI)

    Scrutton, M.E.; Escalante, G.F.

    1986-07-01

    Exploration for hydrocarbons along the Pacific margin of Central America and northern South America has been limited and spasmodic. Less than 100 exploration wells have been drilled, with nearly 50 of these being in the Santa Elena, Progreso, and Guayas basins in Ecuador. Shows have been reported in some wells, and a few oil seeps are known. The only commercial production established to date has been from the Santa Elena Peninsula in Ecuador in the extreme south of the study area. Understanding of the geology in this part of the continental margin is incomplete at best. This paper reviews present-day knowledge in an attempt to define the sedimentary basins better, to characterize their structure and stratigraphy, and to assess their petroleum prospects. The area of continental margin reviewed is to the north, located northwest of the trench system where oceanic crust of the Cocos plate subducts under the Caribbean plate, and to the south, where the northern part of the Nazca plate collides with the South American plate. This plate tectonic setting forms the framework on which local structural and sedimentary events have created a series of relatively small trench-slope and forearc basins in what is now the coastal plain and adjacent offshore area of Central and South America, south or west of a line of mountain ranges with active volcanism. Sedimentary fill is generally of Tertiary age. The basins and subbasins recognized and described include: in Ecuador - Guayas, Santa Elena, Progreso, Valdivia, Bajo Grande, Manta, Muisne-Esmeraldas, and Borbon; in Colombia - Choco-Pacific; in Panama - Gulf of Panama basin complex (Santiago, Tonosi, Sambu), and Burica-Chiriqui; in Costa Rica - Terraba and Coronado/Tempisque; in Nicaragua - San Juan del Sur; and in the Honduras, El Salvador, and Guatemala - the Pacific coastal basin.

  19. Satellites images, digitized topography, and the recognition of the Xela Caldera, Quezaltenango Valley, Guatemala

    SciTech Connect (OSTI)

    Foley, D. (Pacific Lutheran Univ., Tacoma, WA (United States). Dept. of Earth Sciences); McEwen, A.; Duffield, W. (Geological Survey, Flagstaff, AZ (United States)); Heiken, G. (Los Alamos National Lab., NM (United States))

    1992-01-01

    The authors propose, based on reconnaissance geology studies and interpretation of landforms as depicted by Landsat Thematic Mapper (TM) images combined with digitized topography, that the Quezaltenango basin of Guatemala is part of a caldera. The Quezaltenango basin is an elliptical depression, about 12 by 25 km and about 500 m deep. The proposed Xela Caldera extends beyond the basin more than 10 km to the north. The geomorphological features of the area that are typical of a geologically young large-scale caldera include bounding walls that have steep interior and gentle exterior slopes; broad flat areas at the base of the walls; at least one large block, about 3 by 12 km, that only partly floundered as the caldera collapsed; resurgence of a younger volcanic dome, flow and small-scale caldera complex (last active in 1818); younger volcanoes located along the structural margin of the major caldera (one of which is currently active) lobate features on the caldera margins that may indicate a multiple sequence of eruptions; and an active, high-temperature geothermal system. The valley is coincident with a gravity low. Extensive ash-flow tuff sheets that have no identified source are located north of the caldera, and may be the outflow deposits. The Xela caldera is similar in size to the Atitlan caldera, which lies about 50 km southeast of Quezaltenango. The Xela Caldera, if confirmed by future studies, may contain undiscovered geothermal resources, may present a significant geologic hazard to the more than 400,000 people who occupy the Quezaltenango valley, and may be a new member of the list of magmatic systems that have the capability to change global climate for several years.

  20. Catalog of historic seismicity in the vicinity of the Chixoy-Polochic and Motagua faults, Guatemala. Final report

    SciTech Connect (OSTI)

    White, R.A.

    1984-01-01

    A new catalog of shallow historical earthquakes for the region of the Caribbean-North American plate boundary in Guatemala is presented. The catalog is drawn mostly from original official documents that are considered to be primary accounts. It contains 25 damaging earthquakes, 18 of which have not previously been published. The catalog is estimated to be complete for magnitude 6.5 earthquakes since 1700 for most of the study area. The earthquakes in this catalog can be grouped into periods of seismic activity alternating with extended periods of seismic quiescence. The periods of seismic activity appear to be terminated by the major rupture of either the Chixoy-Polochic or Motagua faults, the two principal sub-parallel faults that form the transform plate boundary in Guatemala. Although the plate boundary is not simple in this region, the alternating nature of the regional seismic activity with seismic quiescence is a classic example of the seismic cycle concept. It is estimated that a very large earthquake (M 7.5) may recur along a transform boundary fault between 160 to 300 years after the previous such earthquake in the region. 20 refs., 5 figs.

  1. La actividad teatral en Guatemala en la primera mitad del siglo XX

    E-Print Network [OSTI]

    Ferná ndez Molina, Manuel

    1996-04-01

    este período en la historia del teatro guatemalteco estriba en que fue durante esta época que los espectáculos escénicos empezaron -lenta y progresivamente- a ser realizados por nacionales, especialmente a partir de los terremotos de 1917. Los... con público más asegurado era la de teatro lírico de compañías extranjeras, y esto fue así hasta los terremotos de diciembre de 1917 y enero de 1918 que dañaron seriamente el teatro Colón. La demolición del edificio teatral no se efectuó sino hasta...

  2. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing Capacity forSiliciumEnergy Inc Jump to:Solergy PowerSolisSolmicSolomonSE

  3. Can extractive reserves save the rain forest: A ecological and socioeconomic comparison of non-timber forest product extraction systems in Peten, Guatemala, and West Kalimantan, Indonesia

    SciTech Connect (OSTI)

    Salafsky, N.; Dugelby, B.L.; Terborgh, J.W.

    1992-04-01

    Extractive reserves in tropical rain forests, in which only non-timber products are harvested, have been heralded by some conservationists as a means of maintaining biodiversity while providing income for local people. The study of extraction systems in Peten, Guatemala, and in West Kalimantan, Indonesia, leads to a more tempered conclusion, for while the Peten program was quite successful, the Kalimantan program was not. The study finds the success of an extractive reserve to be contingent on: (1) ecological conditions, and (2) socioeconomic and political factors. Although the study focuses on market-oriented extractive reserves, many of the issues discussed apply as well to other land uses such as the collection of non-timber forest products for household consumption or small-scale timber extraction.

  4. Galp associa se melhor escola de petrleo

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    juntaram-se à Galp para criar o ISPG, que se associou à Heriot Watt University para criar um mestrado em de uma parceria entre o ISPG e a Heriot Watt University, considera- da a melhor instituição de qualificado e de I&D deste sector para as operações que desenvolve em muitos países lusófo- nos, como Brasil

  5. University Ave SE University Ave W

    E-Print Network [OSTI]

    Thomas, David D.

    University Ave SE University Ave W Service Layer Credits: Sources: Esri, DeLorme, NAVTEQ, USGS, Intermap, i UV55 ")280 University Ave. Ramp Major Access Routes University Ave. Ramp §¨¦35W §¨¦94 ")280 Date: 5/30/2014 #12;, , , , , , , ""A TCF Bank Stadium Access Routes University Ave. Ramp University Ave SE Service

  6. REPRESENTATIVE COURSE SEQUENCE SOFTWARE ENGINEERING (SE)

    E-Print Network [OSTI]

    Huang, Haiying

    REPRESENTATIVE COURSE SEQUENCE SOFTWARE ENGINEERING (SE) Freshman Year First Semester Second Semester Second Semester CSE 3310 ­ Fundamentals of Software CSE 3302 ­ Programming Languages Engineering CSE 3320 ­ Operating Systems CSE 3315 ­ Theoretical Concepts in CSE CSE 4310 ­ Software Engineering

  7. Enriched $^{82}$Se for the LUCIFER experiment

    E-Print Network [OSTI]

    J. W. Beeman; F. Bellini; P. Benetti; L. Cardani; N. Casali; D. Chiesa; M. Clemenza; I. Dafinei; S. Di Domizio; F. Ferroni; L. Gironi; A. Giuliani; C. Gotti; M. Laubenstein; M. Maino; S. Nagorny; S. Nisi; C. Nones; F. Orio; L. Pagnanini; L. Pattavina; G. Pessina; G. Piperno; S. Pirro; E. Previtali; C. Rusconi; K. Schäffner; C. Tomei; M. Vignati

    2015-08-07

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of $^{82}$Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched $^{82}$Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3% enriched $^{82}$Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of $^{232}$Th, $^{238}$U and $^{235}$U are respectively: $<$61 $\\mu$Bq/kg, $<$110 $\\mu$Bq/kg and $<$74 $\\mu$Bq/kg at 90% C.L.. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the $^{82}$Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of $^{82}$Se to 0$^+_1$, 2$^+_2$ and 2$^+_1$ excited states of $^{82}$Kr of 3.4$\\cdot$10$^{22}$ y, 1.3$\\cdot$10$^{22}$ y and 1.0$\\cdot$10$^{22}$ y, respectively, with a 90% C.L..

  8. ARCHITECTURE OVERVIEW TIPSTER SE/CM

    E-Print Network [OSTI]

    ARCHITECTURE OVERVIEW TIPSTER SE/CM tipster@fipster.org THE TIPSTER ARCHITECTURE The TIPSTER Architecture is a software architecture for providing Document Detection (i.e. Document Retrieval and Message Routing) and Information Extraction functions to text handling applications. The high level architecture

  9. Enriched $^{82}$Se for the LUCIFER experiment

    E-Print Network [OSTI]

    Beeman, J W; Benetti, P; Cardani, L; Casali, N; Chiesa, D; Clemenza, M; Dafinei, I; Di Domizio, S; Ferroni, F; Gironi, L; Giuliani, A; Gotti, C; Laubenstein, M; Maino, M; Nagorny, S; Nisi, S; Nones, C; Orio, F; Pagnanini, L; Pattavina, L; Pessina, G; Piperno, G; Pirro, S; Previtali, E; Rusconi, C; Schäffner, K; Tomei, C; Vignati, M

    2015-01-01

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of $^{82}$Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched $^{82}$Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3% enriched $^{82}$Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of $^{232}$Th, $^{238}$U and $^{235}$U are respectively: $<$61 $\\mu$Bq/kg, $<$110 $\\mu$Bq/kg and $<$74 $\\mu$Bq/kg at 90% C.L.. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the $^{82}$...

  10. NPS-SE-10-003 POSTGRADUATE

    E-Print Network [OSTI]

    NPS-SE-10-003 NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA INTEGRATED PROJECT An Integrated Command and Control Architecture Concept for Unmanned Systems in the Year of 2030 By Omari D Buckley reporting burden for this collection of information is estimated to average 1 hour per response, including

  11. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop Inc Jump to:Newberg,Energy LLCALLETE Inc dEAPrysmianPvT Capital GmbhQ Cells SE

  12. Scientific Achievement Networks of highly photoresponsive crystalline GaSe

    E-Print Network [OSTI]

    Geohegan, David B.

    Scientific Achievement Networks of highly photoresponsive crystalline GaSe nanosheets a crystalline GaSe target was adjusted to directly grow networks of interconnected triangular GaSe crystalline nanosheets of ~ 200 nm size (inset shows atomic

  13. 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

  14. SE-72/AS-72 generator system based on Se extraction/ As reextraction

    DOE Patents [OSTI]

    Fassbender, Michael Ernst; Ballard, Beau D

    2013-09-10

    The preparation of a .sup.72Se/.sup.72As radioisotope generator involves forming an acidic aqueous solution of an irradiated alkali bromide target such as a NaBr target, oxidizing soluble bromide in the solution to elemental bromine, removing the elemental bromine, evaporating the resulting solution to a residue, removing hydrogen chloride from the residue, forming an acidic aqueous solution of the residue, adding a chelator that selectively forms a chelation complex with selenium, and extracting the chelation complex from the acidic aqueous solution into an organic phase. As the .sup.72Se generates .sup.72As in the organic phase, the .sup.72As may be extracted repeatedly from the organic phase with an aqueous acid solution.

  15. MgSe/ZnSe/CdSe coupled quantum wells grown on InP substrate with intersubband absorption covering 1.55??m

    SciTech Connect (OSTI)

    Chen, Guopeng; Shen, Aidong; De Jesus, Joel; Tamargo, Maria C.

    2014-12-08

    The authors report the observation of intersubband (ISB) transitions in the optical communication wavelength region in MgSe/ZnSe/CdSe coupled quantum wells (QWs). The coupled QWs were grown on InP substrates by molecular beam epitaxy. By inserting ZnSe layers to compensate the strain, samples with high structural quality were obtained, as indicated by well resolved satellite peaks in high-resolution x-ray diffraction. The observed ISB transition energies agree well with the calculated values.

  16. 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

  17. Twinning effect on photoluminescence spectra of ZnSe nanowires

    SciTech Connect (OSTI)

    Xu, Jing; Wang, Chunrui Wu, Binhe; Xu, Xiaofeng; Chen, Xiaoshuang; Oh, Hongseok; Baek, Hyeonjun; Yi, Gyu-Chul

    2014-11-07

    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.

  18. 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.

    2014-05-15

    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.

  19. CuInSe/sub 2/-based photoelectrochemical cells: their use in characterization of thin CuInSe/sub 2/ films, and as photovoltaic cells per se

    SciTech Connect (OSTI)

    Cahen, D.; Chen, Y.W.; Ireland, P.J.; Noufi, R.; Turner, J.A.; Rincon, C.; Bachmann, K.J.

    1984-05-01

    Photoelectrochemistry has been employed to characterize the p-CuInSe/sub 2/ component of the CdS/CuInSe/sub 2/ on-metal and a nonaqueous electrolyte containing a redox couple not specifically adsorbed onto the semiconductor, we can test the films for photovoltaic activity and obtain effective electronic properties of them, before CdS deposition, in a nondestructive manner. Electrochemical decomposition of CuInSe/sub 2/ was investigated in acetonitrile solutions to determine the mechanism of decomposition (n and p) in the dark and under illumination. Electrochemical, solution chemical and surface analyses confirmed at the light-assisted decomposition of CuInSe/sub 2/ resulted in metal ions and elemental chalcogen. On the basis of the results from the electrochemical decomposition, and studies on the solid state chemistry of the (Cu/sub 2/Se)/sub x/(In/sub 2/Se/sub 3/)/sub 1-x/ system and surface analyses, the CuInSe/sub 2//polyiodide interface was stabilized and up to 11.7% conversion efficiencies were obtained.

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

    SciTech Connect (OSTI)

    Mi, Wenlong; Lv, Yanhong; Qiu, Pengfei; Shi, Xun E-mail: cld@mail.sic.ac.cn; Chen, Lidong E-mail: cld@mail.sic.ac.cn; Zhang, Tiansong

    2014-03-31

    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.

  1. 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.; Klymovych, O. S.; Zmiy, O. F.; Myronchuk, G. L.; Zamuruyeva, O. V.; Alahmed, Z. A.; Chyský, J.; Bila, Jiri; Kamarudin, H.

    2014-10-14

    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.

  2. www.medicine.gu.se Minnesanteckningar forskarutbildningsutskottet, inst. fr medicin

    E-Print Network [OSTI]

    www.medicine.gu.se Minnesanteckningar forskarutbildningsutskottet, inst. för medicin 2015 inflammationsforskning hälsas välkommen som ny ledamot i FUU. Per Ladenvall vid avd. för molekylär och klinisk medicin

  3. Improving International Fisheries Management

    E-Print Network [OSTI]

    .............................................................................................................................................31 4. Guatemala

  4. CdSe self-assembled quantum dots with ZnCdMgSe barriers emitting throughout the visible spectrum

    SciTech Connect (OSTI)

    Perez-Paz, M. Noemi; Zhou Xuecong; Munoz, Martin; Lu Hong; Sohel, Mohammad; Tamargo, Maria C.; Jean-Mary, Fleumingue; Akins, Daniel L.

    2004-12-27

    Self-assembled quantum dots of CdSe with ZnCdMgSe barriers have been grown by molecular beam epitaxy on InP substrates. The optical and microstructural properties were investigated using photoluminescence (PL) and atomic force microscopy (AFM) measurements. Control and reproducibility of the quantum dot (QD) size leading to light emission throughout the entire visible spectrum range has been obtained by varying the CdSe deposition time. Longer CdSe deposition times result in a redshift of the PL peaks as a consequence of an increase of QD size. AFM studies demonstrate the presence of QDs in uncapped structures. A comparison of this QD system with CdSe/ZnSe shows that not only the strain but also the chemical properties of the system play an important role in QD formation.

  5. ME/SE 740 Vision, Robotics & Planning Spring 2009

    E-Print Network [OSTI]

    Lin, Xi

    ME/SE 740 ­ Vision, Robotics & Planning Spring 2009 Professor Pierre Dupont, Room 408, 110 Cummington Street 353-9596 pierre@bu.edu Required Text: A Mathematical Introduction to ROBOTIC MANIPULATION://www.engin.umich.edu/group/ctm/basic/basic.html #12;ME/SE 740 ­ Vision, Robotics & Planning 1/22/20092 Course Topics: 1. Introduction: · Historical

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

    E-Print Network [OSTI]

    Eckstrand for Office of Fusion Energy Sciences Fusion Energy Sciences Program Update www.ofes.fusion.doe.gov U.S. Department of Energy's Office of Science #12;APS/DPP 111207-se 2 Topics · Budget status/DPP 111207-se 3 FY 2008 Fusion Energy Sciences Congressional Budget Request 144.6 146.3 20.8 311.7 FY 2007

  7. Approved Module Information for SE4031, 2014/5 Module Title/Name: Extended Integrative Option Module Code: SE4031

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for SE4031, 2014/5 Module Title/Name: Extended Integrative Option Module Code: SE4031 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 30 Module Management Information Module Leader Name Trevor Oliver Email Address t

  8. Optical Probing of metamagnetic phases in epitaxial EuSe

    SciTech Connect (OSTI)

    Galgano, G. D.; Henriques, A. B.; Bauer, G.; Springholz, G.

    2011-12-23

    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.

  9. Enhanced thermoelectric power and electronic correlations in RuSe?

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

    Wang, Kefeng; Wang, Aifeng; Tomic, A.; Wang, Limin; Abeykoon, A. M. Milinda; Dooryhee, E.; Billinge, S. J.L.; Petrovic, C.

    2015-03-03

    We report the electronic structure, electric and thermal transport properties of Ru??xIrxSe? (x ? 0.2). RuSe? is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe? exceeds -200 µV/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. Ru?.?Ir?.?Se? 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 RuSb?.

  10. Hot exciton transport in ZnSe quantum wells

    E-Print Network [OSTI]

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

    2002-02-01

    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...

  11. Optical Properties of CdSe Nanoparticle Assemblies

    SciTech Connect (OSTI)

    Huser, T; Gerion, D; Zaitseva, N; Krol, D M; Leon, F R

    2003-11-24

    We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.

  12. Magneto-optical characterizations of FeTe???Se??? thin...

    Office of Scientific and Technical Information (OSTI)

    in the two thin films. Compared with bulk crystals, FeTeSe thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive for...

  13. Computando lo aspero Por que se cuelgan las computadoras?

    E-Print Network [OSTI]

    Figueira, Santiago

    ejemplo 0 + 1 = 1. Tambi´en puedo al 1 sumarle 1 y obtener el 2: (0 + 1) + 1 = 2 recursi´on: una funci´on que se llama a s´i misma. Por ejemplo, a la funci´on suma se puede definir como: suma(m, n) = n si m´olo un peque~no n´umero de s´imbolos reciben atenci´on (en el ejemplo, 2). Hay una cantidad finita de s

  14. Synthesis and properties of new CdSe-AgI-As{sub 2}Se{sub 3} chalcogenide glasses

    SciTech Connect (OSTI)

    Kassem, M.; ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque ; Le Coq, D.; Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E.; ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque

    2011-02-15

    Research highlights: {yields} Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system. {yields} Characterization of macroscopic properties of the new CdSe-AgI-As{sub 2}Se{sub 3} glasses. {yields} Far infrared transmission of chalcogenide glasses. {yields} Characterization of the total conductivity of CdSe-AgI-As{sub 2}Se{sub 3} glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T{sub g}), crystallisation (T{sub x}), and melting (T{sub m}) temperatures are reported and used to calculate their {Delta}T = T{sub x} - T{sub g} and their Hruby, H{sub r} = (T{sub x} - T{sub g})/(T{sub m} - T{sub x}), criteria. Evolution of the total electrical conductivity {sigma} and the room temperature conductivity {sigma}{sub 298} was also studied. The terahertz transparency domain in the 50-600 cm{sup -1} region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  15. Giant Piezoelectricity in Monolayer Group IV Monochalcogenides: SnSe, SnS, GeSe and GeS

    E-Print Network [OSTI]

    Fei, Ruixiang; Li, Ju; Yang, Li

    2015-01-01

    We predict enormous piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their characteristic piezoelectric coefficients are about two orders of magnitude larger than those of other 2D materials, such as MoS2 and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique "puckered" D2h symmetry and weaker chemical bonds of monolayer group IV monochalcogenides. Given the achieved experimental advances in fabrication of monolayers, their flexible character and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications, such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  16. Excited-State Relaxation in PbSe Quantum Dots

    SciTech Connect (OSTI)

    An, J. M.; Califano, M.; Franceschetti, A.; Zunger, A.

    2008-01-01

    In solids the phonon-assisted, nonradiative decay from high-energy electronic excited states to low-energy electronic excited states is picosecond fast. It was hoped that electron and hole relaxation could be slowed down in quantum dots, due to the unavailability of phonons energy matched to the large energy-level spacings ('phonon-bottleneck'). However, excited-state relaxation was observed to be rather fast ({le}1 ps) in InP, CdSe, and ZnO dots, and explained by an efficient Auger mechanism, whereby the excess energy of electrons is nonradiatively transferred to holes, which can then rapidly decay by phonon emission, by virtue of the densely spaced valence-band levels. The recent emergence of PbSe as a novel quantum-dot material has rekindled the hope for a slow down of excited-state relaxation because hole relaxation was deemed to be ineffective on account of the widely spaced hole levels. The assumption of sparse hole energy levels in PbSe was based on an effective-mass argument based on the light effective mass of the hole. Surprisingly, fast intraband relaxation times of 1-7 ps were observed in PbSe quantum dots and have been considered contradictory with the Auger cooling mechanism because of the assumed sparsity of the hole energy levels. Our pseudopotential calculations, however, do not support the scenario of sparse hole levels in PbSe: Because of the existence of three valence-band maxima in the bulk PbSe band structure, hole energy levels are densely spaced, in contradiction with simple effective-mass models. The remaining question is whether the Auger decay channel is sufficiently fast to account for the fast intraband relaxation. Using the atomistic pseudopotential wave functions of Pb{sub 2046}Se{sub 2117} and Pb{sub 260}Se{sub 249} quantum dots, we explicitly calculated the electron-hole Coulomb integrals and the P {yields} S electron Auger relaxation rate. We find that the Auger mechanism can explain the experimentally observed P {yields} S intraband decay time scale without the need to invoke any exotic relaxation mechanisms.

  17. 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

  18. 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

  19. ctualmente se afronta una im-portante prdida de biodiversi-

    E-Print Network [OSTI]

    Figuerola, Jordi

    a los medios de comunicación y sean cada vez más tratadas en la prensa científica, no son un fenómeno enfermedades con nuestras actividades por encima del nivel que se daba en siglos ante- riores. Por último y percepción pública sobre la necesidad de conservar el medio natural (¿no sería mejor ma- tar a todos los

  20. www.medicine.gu.se Minnesanteckningar Forskarutbildningsutskottet, inst. fr medicin

    E-Print Network [OSTI]

    www.medicine.gu.se Minnesanteckningar ­ Forskarutbildningsutskottet, inst. för medicin 2015, forskare vid avd. för molekylär och klinisk medicin hälsas välkommen som ny ledamot i FUU. Pauline ersätter informerade om hur antagningarna granskas vid avd. för molekylär och klinisk medicin. De vanligaste bristerna

  1. Transformation toughening in an antiferroelectric ceramic *, S.E. Younga

    E-Print Network [OSTI]

    Hong, Wei

    1 Transformation toughening in an antiferroelectric ceramic X. Tana, *, S.E. Younga , Y.H. Seob , J of the crystal symmetry, dielectric constant, field-induced polarization, and Raman spectrum on ceramic Pb0.99Nb0 is demonstrated in the antiferroelectric ceramic with both indentation fracture and R-curve experiments

  2. 2030 SE Marine Science Drive Newport, Oregon 973665-5296

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    2030 SE Marine Science Drive Newport, Oregon 973665-5296 Telephone 541-867-0100 Fax 541-867-0138 Web Page http://hmsc.oregonstate.edu Oregon State University Hatfield Marine Science Center 2006.....................................2 Coastal Oregon Marine Experiment Station...........................2 OSU-COMES Seafood Research

  3. Quantum confined acceptors and donors in InSe nanosheets

    SciTech Connect (OSTI)

    Mudd, G. W.; Patanè, A. Makarovsky, O.; Eaves, L.; Kudrynskyi, Z. R.; Kovalyuk, Z. D.; Fay, M. W.; Zólyomi, V.; Falko, V.

    2014-12-01

    We report on the radiative recombination of photo-excited carriers bound at native donors and acceptors in exfoliated nanoflakes of nominally undoped rhombohedral ?-polytype InSe. The binding energies of these states are found to increase with the decrease in flake thickness, L. We model their dependence on L using a two-dimensional hydrogenic model for impurities and show that they are strongly sensitive to the position of the impurities within the nanolayer.

  4. Does MoSE cope with inland tsunamis hazard?

    E-Print Network [OSTI]

    Panza, Giuliano Francesco; Romanelli, Fabio

    2014-01-01

    In this work we use morphostructural zonation and pattern recognition techniques to identify a potential seismic source located inland very near Venice, and then we evaluate how a tsunami wave generated from this source can affect the MoSE gates if they are standing up (closed) during the tsunami event. From our simulation we get both peaks and troughs as first arrivals: the behavior of the barriers in these two situations could be a very important design matter.

  5. Perlick: Order (2013-SE-14001) | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuilding energy codes havePUBLICofPatriciaOrder (2013-SE-14001)

  6. Perlick: Proposed Penalty (2013-SE-14001) | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuilding energy codes havePUBLICofPatriciaOrder (2013-SE-14001)Proposed

  7. Metal contacts on ZnSe and GaN

    SciTech Connect (OSTI)

    Duxstad, K J [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering

    1997-05-01

    Recently, considerable interest has been focused on the development of blue light emitting materials and devices. The focus has been on GaN and ZnSe, direct band gap semiconductors with bands gaps of 3.4 and 2.6 eV, respectively. To have efficient, reliable devices it is necessary to have thermally and electrically stable Ohmic contacts. This requires knowledge of the metal-semiconductor reaction behavior. To date few studies have investigated this behavior. Much information has accumulated over the years on the behavior of metals on Si and GaAs. This thesis provides new knowledge for the more ionic wide band gap semiconductors. The initial reaction temperatures, first phases formed, and phase stability of Pt, Pd, and Ni on both semiconductors were investigated. The reactions of these metals on ZnSe and GaN are discussed in detail and correlated with predicted behavior. In addition, comparisons are made between these highly ionic semiconductors and Si and GaAs. The trends observed here should also be applicable to other II-VI and III-Nitride semiconductor systems, while the information on phase formation and stability should be useful in the development of contacts for ZnSe and GaN devices.

  8. APdCu(Se2)(Se3) (A ) K and Rb): New Quaternary Copper Palladium Polyselenides with Unusual Metal-Selenium Coordination

    E-Print Network [OSTI]

    Li, Jing

    APdCu(Se2)(Se3) (A ) K and Rb): New Quaternary Copper Palladium Polyselenides with Unusual Metal structurally characterized quaternary copper palladium polychalcogenides with a (Se2)2- and a (Se3)2- fragment ) K and Rb), which are the first quaternary copper palladium polychalcogenides obtained

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

    DOE Patents [OSTI]

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

    2013-08-20

    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.

  10. Sunshine Lighting: Order (2014-SE-54008) | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLEStatutory Authority forPerk | DepartmentOrder (2014-SE-54008)

  11. Victory: Order (2015-SE-42033) | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLEStatutoryinEnable LowNewsEnergyOrder (2015-SE-42033) Victory:

  12. Victory: Proposed Penalty (2015-SE-42033) | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLEStatutoryinEnable LowNewsEnergyOrder (2015-SE-42033)

  13. 1.0 Espa,cos de Banach de se,c"oes de um fibrado vetorial. Definiremos nesta se,c"ao v'arios espa,cos vetoriais de se,c"oes de um fibr*

    E-Print Network [OSTI]

    Tausk, Daniel Victor

    1.0 Espa,cos de Banach de se,c"oes de um fibrado vetorial. Definiremos nesta se,c"ao v'arios espa,cos vetoriais de se,c"oes de um fibr* *ado vetorial sobre uma variedade compacta (possivelmente com bordo). Definiremos normas nestes esp* *a,cos mediante as quais eles se tornar"ao espa,cos de

  14. Geometric Tracking Control of a Quadrotor UAV on SE(3)

    E-Print Network [OSTI]

    Lee, Taeyoung; McClamroch, N Harris

    2010-01-01

    This paper provides new results for the tracking control of a quadrotor unmanned aerial vehicle (UAV). The UAV has four input degrees of freedom, namely the magnitudes of the four rotor thrusts, that are used to control the six translational and rotational degrees of freedom, and to achieve asymptotic tracking of four outputs, namely, three position variables for the vehicle center of mass and the direction of one vehicle body-fixed axis. A globally defined model of the quadrotor UAV rigid body dynamics is introduced as a basis for the analysis. A nonlinear tracking controller is developed on the special Euclidean group SE(3) and it is shown to have desirable closed loop properties that are almost global. Several numerical examples, including an example in which the quadrotor recovers from being initially upside down, illustrate the versatility of the controller.

  15. 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)

    2013-11-11

    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.

  16. 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.; Salcedo-Reyes, J. C.

    2014-05-15

    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.

  17. Saving energy in Guatemala (1966, number 8)

    SciTech Connect (OSTI)

    NONE

    1996-12-31

    The report highlights Guatemalan and regional trends in energy consumption and summarizes energy conservation activities conducted through a regional USAID project. It summarizes what evaluators found about changes in conditions resulting from implementing the four strategies: Building institutional capacity to promote and service energy conservation activities; Introducing technology for better energy management; Increasing awareness and understanding about economic and environmental benefits from energy conservation; Reforming policies that discourage environmentally sound energy use; It describes the project`s impact on industrial energy conservations, and on the sustainability and spread of energy conservation practices. Finally, the report presents lessons drawn from the evaluation.

  18. VIGILANTE: Violence and Security in Postwar Guatemala

    E-Print Network [OSTI]

    Sharp, Ellen Jane

    2014-01-01

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

  19. Policy of Primary Health Care in Guatemala

    E-Print Network [OSTI]

    Longchamp, Carla P

    1988-01-01

    56). The lack and maldistribution of workers has exacerbatedsay, however, that the maldistribution of health workers as

  20. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainableGlynn County,Solar JumpInformationGrowindFunan

  1. Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers

    SciTech Connect (OSTI)

    Shen, A.; Lu, H.; Charles, W.; Yokomizo, I.; Tamargo, M. C.; Franz, K. J.; Gmachl, C.; Zhang, S. K.; Zhou, X.; Alfano, R. R.; Liu, H. C.

    2007-02-12

    The authors report the observation of intersubband absorption in multilayers of CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dots. The samples were grown by molecular beam epitaxy on InP substrates. For samples with the CdSe dot layers doped with Cl and with the deposited CdSe equivalent layer thickness between 5.2 and 6.9 ML, peak absorption between 2.5 and 3.5 {mu}m was observed. These materials are promising for intersubband devices operating in the mid- and near-infrared ranges.

  2. Secretary Chu to Lead Delegation to SE4All, CEM Conferences in...

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

    to Lead Delegation to SE4All, CEM Conferences in London Secretary Chu to Lead Delegation to SE4All, CEM Conferences in London April 9, 2012 - 10:13am Addthis WASHINGTON, DC - Later...

  3. Sbado 10.11.2012 English | Deutsch | Franais | Italiano | Espaol | Portugus | | | Fazer login | Cadastre-se

    E-Print Network [OSTI]

    Barbosa, Marcia C. B.

    dispararam contra drone dos EUA 09 Novembro, 2012 - 16:57 O sobrinho de George W. Bush, meio hispânico, se

  4. SE2NN11 Neural Networks Part B Dr Richard Mitchell, 2014 1

    E-Print Network [OSTI]

    Mitchell, Richard

    SE2NN11 ­ Neural Networks ­ Part B © Dr Richard Mitchell, 2014 1 p1 RJM 16/09/14 SE2NN11 Neural Networks ­ Part B © Dr Richard Mitchell 2014 SE2NN11 Neural Networks : Part B In Part B of the course, I Networks Including Stochastic Diffusion Search p2 RJM 16/09/14 SE2NN11 Neural Networks ­ Part B © Dr

  5. Energy relaxation in CdSe nanocrystals: the effects of morphology and film preparation

    E-Print Network [OSTI]

    Ruan, Xiulin

    solar cells. harvesting light energy with CdSe nanocrystals molecularly linked to mesoscopic TiO2 filmsEnergy relaxation in CdSe nanocrystals: the effects of morphology and film preparation Bryan T time-resolved absorption spectroscopy is used to investigate exciton dynamics in CdSe nanocrystal films

  6. 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

  7. Method of synthesizing and growing copper-indium-diselenide (CuInSe/sub 2/) crystals

    DOE Patents [OSTI]

    Ciszek, T.F.

    1984-11-29

    A process for preparing CuInSe/sub 2/ crystals includes melting a sufficient quantity of B/sub 2/O/sub 2/ along with stochiometric quantities of Cu, In, and Se in a crucible in a high-pressure atmosphere of inert gas to encapsulate the CuInSe/sub 2/ melt and confine the Se to the crucible. Additional Se in the range of 1.8 to 2.2% over the stochiometric quantity is preferred to make up for small amounts of Se lost in the process. The melt can then be cooled slowly to form the crystal as direct solidification, or the crystal can be grown by inserting a seed crystal through the B/sub 2/O/sub 3/ encapsulate into contact with the CuInSe/sub 2/ melt and withdrawing the seed upwardly to grow the crystal thereon from the melt.

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

    SciTech Connect (OSTI)

    Dewberry, R.A.

    2000-08-21

    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.

  9. SLU, Box 58, SE-230 53Alnarp, Sverige tel: +46 (0)40-4150 00 Org.nr 202100-2817 info@slu.se

    E-Print Network [OSTI]

    .slu.se 1(7) FUSE- Future Urban Sustainable Environments Caroline Dahl, projektledare STRATEGISK PLAN Strategisk plan för FUSE verksamhetsperiod 2013-2016 Projektnamn: Future Urban Sustainable Environment, FUSE

  10. 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

    2009-03-16

    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.

  11. Enhanced ripening behavior of Mg-doped CdSe quantum dots

    E-Print Network [OSTI]

    Kim, Tae-Geun

    In this study, CdO and Mg acetate were added into a mixture of paraffin oil and oleic acid (45:5) by 5 and 1 mEnhanced ripening behavior of Mg-doped CdSe quantum dots Yun-Mo Sung,a) Woo-Chul Kwak, and Woong November 2007; accepted 24 March 2008) Pure CdSe and Mg-doped CdSe nanocrystal quantum dots were

  12. Hot-pressed ceramic Cr2+ :ZnSe gain-switched

    E-Print Network [OSTI]

    Mirov, Sergey B.

    Hot-pressed ceramic Cr2+ :ZnSe gain-switched laser A. Gallian, V. V. Fedorov, and S. B. Mirov: The technology of hot-pressed Cr2+ :ZnSe ceramic preparation is reported. Comparative gain-switched lasing of hot­pressed ceramic and CVD grown Cr2+ :ZnSe samples with slope efficiencies up to 10 % and output energies up to 2 m

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

    E-Print Network [OSTI]

    Sites, James R.

    OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS Thin-film solar cells have the potential to be an important contributor to the global energy demand by the mid-21st-century. Cu(In,Ga)Se2 (CIGS) solar cells, which haveDISSERTATION DEVICE PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS Submitted by Markus Gloeckler

  14. Rural areas electrification (Latin America), Guatemala City, Guatemala, June 4--7, 1989: Foreign trip report

    SciTech Connect (OSTI)

    Katzman, M.T.

    1989-01-01

    ORNL serves the function of monitoring the Central American Rural Electrification Support Program (CARES) of US Agency for International Development (USAID), which is administered by NRECA. The results of the Demand Assessment Model, presented at the conference, were reviewed, and a paper on the use of marginal cost analysis for rural electrification was delivered for presentation by NRECA staff. Discussions on the acceptability of the model were discussed with utility representatives.

  15. Mechanical and electronic-structure properties of compressed CdSe tetrapod nanocrystals

    E-Print Network [OSTI]

    Schrier, Joshua; Lee, Byounghak; Wang, Lin-Wang

    2008-01-01

    Mechanical and electronic-structure properties of compressed94720 USA The coupling of mechanical and optical propertiestheoretical examination of the mechanical properties of CdSe

  16. Photovoltaic performance of ultra-small PbSe quantum dots

    E-Print Network [OSTI]

    Ma, Wanli

    2014-01-01

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

  17. Photovoltaic Devices Employing Ternary PbSxSe1-x Nanocrystals

    E-Print Network [OSTI]

    Alivisatos, A. Paul

    2009-01-01

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

  18. PERFORMANCE OF CdSe TETRAPODS-GOLD AS NANOSTRUCTURE ELECTROCHEMICAL MATERIALS IN PHOTOVOLTAIC CELLS

    E-Print Network [OSTI]

    Natelson, Douglas

    PERFORMANCE OF CdSe TETRAPODS-GOLD AS NANOSTRUCTURE ELECTROCHEMICAL MATERIALS IN PHOTOVOLTAIC CELLS antenna arrays are assembled by coating on CdSe tetrapod templates; the rectifying barrier is formed and reduce the costs associated with conventional solar cells, including multi-bandgap materials [5

  19. Ultrafast Spectroscopy of CdSe Nanocrystals: Morphological and Environmental Effects on Nonradiative and Nonadiabatic Relaxation

    E-Print Network [OSTI]

    Xu, Xianfan

    Ultrafast Spectroscopy of CdSe Nanocrystals: Morphological and Environmental Effects of various morpholo- gies has been demonstrated in CdSe, such as quantum dots (QDs),3 quantum rods (QRs),4 devices and technologies have come to fruition, for example, nanocrystal solar cells (NCSC),7 lasers,8

  20. Volume 42, number 2 OPTICSCOMMUNICATIONS 15 June 1982 ELECTRON BEAM PUMPED CW Se II LASER ~

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Volume 42, number 2 OPTICSCOMMUNICATIONS 15 June 1982 ELECTRON BEAM PUMPED CW Se II LASER ~ J of singlyionized seleniumusingan electron beam to excite a He-Se mixture. The variation of the laser output power as a function of the electron beam dischargeparameters is reported. Recently we obtained cw laser radiation from

  1. 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

  2. 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

  3. ME/SE 762 Nonlinear Systems and Control Location: SOC B63

    E-Print Network [OSTI]

    Lin, Xi

    ME/SE 762 Nonlinear Systems and Control Location: SOC B63 Time: Tue & Thu 12-2 Instructor: Calin-4 #12;ME/SE 762 Nonlinear Systems and Control Prerequisites: a grad-level class on linear systems: · stability analysis of nonlinear systems (with emphasis on Lyapunov theory) · nonlinear feedback control

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

    SciTech Connect (OSTI)

    ERTEN ESER

    2012-01-22

    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.

  5. Surface Plasmon Excitation via Au Nanoparticles in CdSe Semiconductor

    SciTech Connect (OSTI)

    Pradhan, A. K.; Konda, R. B.; Mundle, R.; Mustafa, H.; Bamiduro, O.; Roy, U. N.; Cui, Y.; Burger, A.

    2008-10-23

    We present experimental evidence for the large Raman and photoluminescence enhancement in CdSe semiconductor films grown on Si and glass substrates due to excitation of surface plasmon resonances in proximate gold metal nanoparticles deposited on the surface of CdSe film. Heterojunction diodes containing n-CdSe on p-Si semiconductor were fabricated and the surface of the diodes was in situ coated with Au nanoparticles using the ultra-high vacuum pulsed-laser deposition technique. A significant enhancement of the photocurrent was obtained in CdSe/p-Si containing Au nanoparticles on the surface compared to CdSe/p-Si due to the enhanced photo-absorption within the semiconductor by the phenomenon of surface plasmon resonance. These observations suggest a variety of approaches for improving the performance of devices such as photodetectors, photovoltaic, and related devices, including biosensors.

  6. Approved Module Information for SE12EM, 2014/5 Module Title/Name: Mathematics for 1st year Engineers Module Code: SE12EM

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Engineers Module Code: SE12EM School: Engineering and Applied Science Module Type: Standard Module New (Enhanced Honours) Programmes in which available: BEng Mechanical Engineering Systems. BEng/MEng Electromechanical Engineering. BEng/MEng Mechanical Engineering. BEng Electrical Engineering Systems. BEng

  7. Module Information for SE0SLF, 2015/6 -APPROVED Module Title/Name: Systems and Logistics Foundations Module Code: SE0SLF

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Module Information for SE0SLF, 2015/6 - APPROVED Module Title/Name: Systems and Logistics thinking and its role in engineering ? To provide students with a knowledge of the role of logistics in society Module Learning Outcomes: ? To describe the role of systems and logistics in engineering and wider

  8. 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...

  9. Probing the size and environment induced phase transformation in CdSe quantum dots

    SciTech Connect (OSTI)

    Karakoti, Ajay S.; Sanghavi, Shail P.; Nachimuthu, Ponnusamy; Yang, Ping; Thevuthasan, Suntharampillai

    2011-11-17

    The structural and electronic properties of CdSe quantum dots in toluene and drop-casted on Si wafer were investigated by in-situ micro X-ray diffraction, X-ray photoelectron spectroscopy and UV-Vis absorption and emission spectroscopy. The in-situ micro diffraction data show that the CdSe quantum dots capped with TOPO or hexadecylamine (HDA) in toluene exhibit predominantly wurtzite crystal structure, which undergoes a phase transformation to zinc blende crystal structure following drop casting on Si and this phase transition increases with decreasing the size of the CdSe quantum dots. Decreasing the size of quantum dots also increases the Se vacancies that facilitate the phase transformation. The X-ray photoelectron spectra show a systematic increase in the core level binding energies of Cd 3d and Se 3d, the band gap and the Cd/Se ratio as the size of the quantum dots decreases from 6.6nm to 2.1nm. This is attributed to the quantum confinement of CdSe crystallites by the capping ligands in toluene which increases with decreasing the size of the quantum dots. However, drop-casting quantum dots on Si alter the density and arrangement of capping ligands and solvent molecules on the quantum dots which causes significant phase transformation.

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

    SciTech Connect (OSTI)

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

    2010-07-01

    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.

  11. 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

    2010-06-30

    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.

  12. Ann bay lodyans 11 / Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 11 Se Bryant Freeman ("Tonton Liben...") ki pare ti liv sa a. AYITI SE PEP AYISYEN PM 7854 .H39 A56 2000 PM Enstiti Etid Ayisyen - Inivesite Kannzas Bon Nouvel Fondasyon Alfa Lwes 1997 YON PWASON KI RELE TEZEN Vwala se yon jennfi yo rele Wozilya ak yon jennjan yo rele Tezen ki...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 fcjNlVfcHto" r ' K A N S A S L lBf iAH.r ANN BAY... LODYANS1 4 Se Bryant Freeman ("Tonton Liben") ki pare ti liv sa a. A 51* AYITI SE PEP AYISYEN PM 7854 .H39 A56 2000 v. 14 Enstiti Etid Ayisyen - Inivesite Kannzas Bon Nouvel Fondasyon Alfa Lwes 2000 YON TI PYE ZORANJ Se istwa yon ti fi ki...

  14. Lattice dynamics of BaFe2X3(X=S,Se) compounds

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

    Popovi?, Z. V.; Š?epanovi?, M.; Lazarevi?, N.; Opa?i?, M.; Radonji?, M. M.; Tanaskovi?, D.; Lei, Hechang; Petrovic, C.

    2015-02-27

    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. Low-temperature ferromagnetic properties in Co-doped Ag{sub 2}Se nanoparticles

    SciTech Connect (OSTI)

    Yang, Fengxia E-mail: xia9020@hust.edu.cn; Yu, Gen; Han, Chong; Liu, Tingting; Zhang, Duanming; Xia, Zhengcai E-mail: xia9020@hust.edu.cn

    2014-01-06

    ?-Ag{sub 2}Se is a topologically nontrivial insulator. The magnetic properties of Co-doped Ag{sub 2}Se nanoparticles with Co concentrations up to 40% were investigated. The cusp of zero-field-cooling magnetization curves and the low-temperature hysteresis loops were observed. With increasing concentration of Co{sup 2+} ions mainly substituting Ag{sub I} sites in the Ag{sub 2}Se structure, the resistivity, Curie temperature T{sub c}, and magnetization increased. At 10?T, a sharp drop of resistance near T{sub c} was detected due to Co dopants. The ferromagnetic behavior in Co-doped Ag{sub 2}Se might result from the intra-layer ferromagnetic coupling and surface spin. This magnetic semiconductor is a promising candidate in electronics and spintronics.

  16. Enhanced Thermoelectric Power and Electronic Correlations in RuSe2

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

    Wang, Kefeng; Wang, Aifeng; Tomic, A.; Wang, Limin; Abeykoon, A.M. Milinda; Dooryhee, E.; Billinge, S. J.L.; Petrovic, C.

    2015-04-01

    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.

  17. 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

    2015-02-27

    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

  18. Super-Poissonian Statistics of Photon Emission from Single CdSe...

    Office of Scientific and Technical Information (OSTI)

    Super-Poissonian Statistics of Photon Emission from Single CdSe-CdS Core-Shell Nanocrystals Coupled to Metal Nanostructures Citation Details In-Document Search Title:...

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

    E-Print Network [OSTI]

    Fisher, Brent R

    2005-01-01

    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 ...

  20. Synthesis and structural characterization of ZnTe/ZnSe core/shell tunable quantum dots

    E-Print Network [OSTI]

    Guan, Juan

    2008-01-01

    Colloidal semiconductor nanocrystals or quantum dots have attracted much attention recently with their unique optical properties. Here we present a novel approach to synthesize ZnTe/ZnSe core/shell tunable quantum dots. ...

  1. Efficient light emitting devices utilizing CdSe(ZnS) quantum dots in organic host matrices

    E-Print Network [OSTI]

    Coe-Sullivan, Seth (Seth Alexander)

    2002-01-01

    We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the ...

  2. 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 AND CONSERVATION COUNCIL'S CONSERVATION PLANNING ASSUMPTIONS Weatherization Industries Save Energy (WISE · WEATHERIZATIONALLIES@GMAIL.COM COMMENTS ON ACHIEVABLE SAVINGS: A RETROSPECTIVE LOOK AT THE NORTHWEST POWER

  3. 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

    2011-12-31

    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}.

  4. Thin-film Sb2Se3 photovoltaics with oriented one-dimensional ribbons and benign

    E-Print Network [OSTI]

    Sargent, Edward H. "Ted"

    to the substrate, and produced Sb2Se3 thin-film solar cells with a certified device efficiency of 5.6%. Our results are one of the major limiting factors for high-efficiency thin-film solar cells. We began with first cells based on inorganic absorbers, such as Si, GaAs, CdTe and Cu(In,Ga)Se2, permit a high device

  5. 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

    2011-12-23

    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.

  6. Novel Approaches to Wide Bandgap CuInSe2 Based Absorbers

    SciTech Connect (OSTI)

    William N. Shafarman

    2011-04-28

    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.

  7. Electronic structure, irreversibility line and magnetoresistance of Cu0.3Bi2Se3 superconductor

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

    Hemian, Yi; Gu, Genda; Chen, Chao -Yu; Sun, Xuan; Xie, Zhuo -Jin; Feng, Ya; Liang, Ai -Ji; Peng, Ying -Ying; He, Shao -Long; Zhao, Lin; et al

    2015-06-01

    CuxBi2Se3 is a superconductor that is a potential candidate for topological superconductors. We report our laser-based angle-resolved photoemission measurement on the electronic structure of the CuxBi2Se3 superconductor, and a detailed magneto-resistance measurement in both normal and superconducting states. We find that the topological surface state of the pristine Bi2Se3 topological insulator remains robust after the Cu-intercalation, while the Dirac cone location moves downward due to electron doping. Detailed measurements on the magnetic field-dependence of the resistance in the superconducting state establishes an irreversibility line and gives a value of the upper critical field at zero temperature of ~4000 Oe formore »the Cu0.3Bi2Se3 superconductor with a middle point Tc of 1.9K. The relation between the upper critical field Hc2 and temperature T is different from the usual scaling relation found in cuprates and in other kinds of superconductors. Small positive magneto-resistance is observed in Cu0.3Bi2Se3 superconductors up to room temperature. As a result, these observations provide useful information for further study of this possible candidate for topological superconductors.« less

  8. Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3

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

    Kong, P. P.; Sun, F.; Xing, L. Y.; Zhu, J.; Zhang, S. J.; Li, W. M.; Liu, Q. Q.; Wang, X. C.; Feng, S. M.; Yu, X. H.; et al

    2015-02-17

    Recently, A2B3 type strong spin orbital coupling compounds such as Bi2Te3, Bi2Se3 and Sb2Te3 were theoretically predicated to be topological insulators and demonstrated through experimental efforts. The counterpart compound Sb2Se3 on the other hand was found to be topological trivial, but theoretical studies indicated that the pressure might induce Sb2Se3 into a topological nontrivial state. We report on the discovery of superconductivity in Sb2Se3 single crystal induced via pressure. Our experiments indicated that Sb2Se3 became superconductive at high pressures above 10 GPa proceeded by a pressure induced insulator to metal like transition at ~3 GPa which should be related tomore »the topological quantum transition. The superconducting transition temperature (TC) increased to around 8.0 K with pressure up to 40 GPa while it keeps ambient structure. High pressure Raman revealed that new modes appeared around 10 GPa and 20 GPa, respectively, which correspond to occurrence of superconductivity and to the change of TC slop as the function of high pressure in conjunction with the evolutions of structural parameters at high pressures.« less

  9. In-situ surface composition measurements of CuGaSe{sub 2} thin films

    SciTech Connect (OSTI)

    Fons, P.; Yamada, A.; Niki, S.; Oyanagi, H.

    1998-12-31

    Two CuGaSe{sub 2} films were grown by molecular beam epitaxy onto GaAs (001) substrates with varying Cu/Ga flux ratios under Se overpressure conditions. Growth was interrupted at predetermined times and the surface composition was measured using Auger electron spectroscopy after which growth was continued. After growth, the film composition was analyzed using voltage dependent electron microprobe spectroscopy. Film structure and morphology were also analyzed using x-ray diffraction and atomic force microscopy. The film with a Cu/Ga ratio larger than unity showed evidence of surface segregation of a second Cu-rich phase with a Cu/Se composition ratio slightly greater than unity. A second CuGaSe{sub 2} film with a Cu/Ga ratio of less than unity showed no change in surface composition with time and was also consistent with bulk composition measurements. Diffraction measurements indicated a high concentration of twins as well as the presence of domains with mixed c and a axes in the Ga-rich film. The Cu-rich films by contrast were single domain and had a narrower mosaics. High sensitivity scans along the [001] reciprocal axis did not exhibit any new peaks not attributable to either the substrate or the CuGaSe{sub 2} thin film.

  10. 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

    2015-01-01

    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.

  11. Charge-transfer dynamics in multilayered PbS and PbSe quantum dot architectures

    SciTech Connect (OSTI)

    Xu, F.; Ma, X.; Haughn, C. R.; Doty, M. F.; Cloutier, S. G.

    2014-02-03

    We demonstrate control of the charge transfer process in PbS and PbSe quantum dot assemblies. We first demonstrate efficient charge transfer from donor quantum dots to acceptor quantum dots in a multi-layer PbSe cascade structure. Then, we assemble type-I and type-II heterostructures using both PbS and PbSe quantum dots via careful control of the band alignment. In type-I structures, photo-generated carriers are transferred and localized in the smaller bandgap (acceptor) quantum dots, resulting in a significant luminescence enhancement. In contrast, a significant luminescence quenching and shorter emission lifetime confirms an efficient separation of photo-generated carriers in the type-II architecture.

  12. High Compositional Homogeneity of CdTexSe1-x Crystals Grown by the Bridgman Method

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

    Roy, U. N.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Hossain, A.; Lee, K.; Lee, W.; Tappero, R.; Yang, G.; Gul, R.; et al

    2015-02-03

    We obtained high-quality CdTexSe1-x (CdTeSe) crystals from ingots grown by the vertical Bridgman technique. The compositional uniformity of the ingots was evaluated by X-ray fluorescence at BNL’s National Synchrotron Light Source X27A beam line. The resulting compositional homogeneity was highly uniform throughout the ingot, and the effective segregation coefficient of Se was ~1.0. This uniformity offers potential opportunity to enhance the yield of the materials for both infrared substrate and radiation-detector applications, so greatly lowering the cost of production and also offering us the prospect to grow large-diameter ingots for use as large-area substrates and for producing higher efficiency gamma-raymore »detectors. The concentration of secondary phases was found to be much lower, by eight- to ten fold compared to that of conventional CdxZn1-xTe (CdZnTe or CZT).« less

  13. Substrate induced modulation of electronic, magnetic and chemical properties of MoSe{sub 2} monolayer

    SciTech Connect (OSTI)

    Wasey, A. H. M. Abdul; Chakrabarty, Soubhik; Das, G. P., E-mail: msgpd@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032 (India)

    2014-04-15

    Monolayer of MoSe{sub 2}, having a typical direct band gap of ?1.5 eV, is a promising material for optoelectronic and solar cell applications. When this 2D semiconductor is supported on transition metal substrates, such as Ni(111) and Cu(111), its electronic structure gets modulated. First principles density functional investigation shows the appearance of de-localized mid-gap states in the density of states. The work function of the semiconductor overlayer gets modified considerably, indicating n-type doping caused by the metal contacts. The charge transfer across the metal-semiconductor junction also significantly enhances the chemical reactivity of the MoSe{sub 2} overlayer, as observed by Hydrogen absorption. Furthermore, for Ni contact, there is a signature of induced magnetism in MoSe{sub 2} monolayer.

  14. Role of polycrystallinity in CdTe and CuInSe sub 2 photovoltaic cells

    SciTech Connect (OSTI)

    Sites, J.R. )

    1991-01-01

    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.

  15. Luminescence of CdSe/ZnS quantum dots infiltrated into an opal matrix

    SciTech Connect (OSTI)

    Gruzintsev, A. N. Emelchenko, G. A.; Masalov, V. M.; Yakimov, E. E.; Barthou, C.; Maitre, A.

    2009-02-15

    The effect of the photonic band gap in the photonic crystal, the synthesized SiO{sub 2} opal with embedded CdSe/ZnS quantum dots, on its luminescence in the visible spectral region is studied. It is shown that the position of the photonic band gap in the luminescence and reflectance spectra for the infiltrated opal depends on the diameter of the constituent nanospheres and on the angle of recording the signal. The optimal conditions for embedding the CdSe/ZnS quantum dots from the solution into the opal matrix are determined. It is found that, for the opal-CdSe/ZnS nanocomposites, the emission intensity decreases and the luminescence decay time increases in the spatial directions, in which the spectral positions of the photonic band gap and the luminescence peak of the quantum dots coincide.

  16. Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach

    SciTech Connect (OSTI)

    Schmidt, Th.; Roventa, E.; Clausen, T.; Flege, J. I.; Alexe, G.; Rosenauer, A.; Hommel, D.; Falta, J.; Bernstorff, S.; Kuebel, C.

    2005-11-15

    The vertical and lateral ordering of stacked CdSe quantum dot layers embedded in ZnS{sub x}Se{sub 1-x} has been investigated by means of grazing incidence small angle x-ray scattering and transmission electron microscopy. Different growth parameters have been varied in order to elucidate the mechanisms leading to quantum dot correlation. From the results obtained for different numbers of quantum dot layers, we conclude on a self-organized process which leads to increasing ordering for progressive stacking. The dependence on the spacer layer thickness indicates that strain induced by lattice mismatch drives the ordering process, which starts to break down for too thick spacer layers in a thickness range from 45 to 80 A. Typical quantum dot distances in a range from about 110 to 160 A have been found. A pronounced anisotropy of the quantum dot correlation has been observed, with the strongest ordering along the [110] direction. Since an increased ordering is found with increasing growth temperature, the formation of stacking faults as an additional mechanism for quantum dot alignment can be ruled out.

  17. Two-step growth of two-dimensional WSe2/MoSe2 heterostructures

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

    Gong, Yongji; Lei, Sidong; Lou, Jun; Liu, Zheng; Vajtai, Robert; Zhou, Wu; Ajayan, Pullikel M.

    2015-08-03

    Two dimensional (2D) materials have attracted great attention due to their unique properties and atomic thickness. Although various 2D materials have been successfully synthesized with different optical and electrical properties, a strategy for fabricating 2D heterostructures must be developed in order to construct more complicated devices for practical applications. Here we demonstrate for the first time a two-step chemical vapor deposition (CVD) method for growing transition-metal dichalcogenide (TMD) heterostructures, where MoSe2 was synthesized first and followed by an epitaxial growth of WSe2 on the edge and on the top surface of MoSe2. Compared to previously reported one-step growth methods, thismore »two-step growth has the capability of spatial and size control of each 2D component, leading to much larger (up to 169 ?m) heterostructure size, and cross-contamination can be effectively minimized. Furthermore, this two-step growth produces well-defined 2H and 3R stacking in the WSe2/MoSe2 bilayer regions and much sharper in-plane interfaces than the previously reported MoSe2/WSe2 heterojunctions obtained from one-step growth methods. The resultant heterostructures with WSe2/MoSe2 bilayer and the exposed MoSe2 monolayer display rectification characteristics of a p-n junction, as revealed by optoelectronic tests, and an internal quantum efficiency of 91% when functioning as a photodetector. As a result, a photovoltaic effect without any external gates was observed, showing incident photon to converted electron (IPCE) efficiencies of approximately 0.12%, providing application potential in electronics and energy harvesting.« less

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    , li pa kite anyen deye. Mouche ale ak ni jwet zo li, ni kat li, ni boutey tafya, menm ti bout tanbou a li pa bliye mete. Konsa, kon mouche rive anwo a, li tabli yon jwet zo ak yon jwet kat, ansanm ak yon konmes kleren. Sa fe, pyes travay pa ka fet... sa a se yon danje piblik. Fok yo jwenn bout li. Depi Telisfo vini an, lanfe a vin tounen yon peyi pleziyis. Abitan yo pwofite fe parese. Men tou, Telisfo pa kite yo gen anyen, menm bout sigaret pa ka rete. Sa ki pi red, se chak jou yon moun...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    ("Tonton Liben") ki pare ti liv sa a. AYITI SE PEP AYISYEN PM 7 8 5 4 .H39 A 5 6 2 0 0 0 V . 6 Enstiti Etid Ayisyen - Inivesite Kannzas Bon Nouvel Fondasyon Alfa Lwes 1997 PINGALOT AK ELIFET Vwala te gen yon wa ki rele Pingalot. Men wa sa a... te yon neg sitelman rayisab tout peyi a t ap soufri. Nan peyi sa a te gen yon msye ki rele Elifet. Se te yon bon moun ki te konn travay di, e ki te fe ekonomi jous li rive monte yon gwo kay menm pi bel pase kay wa a. Konsa, Pingalot moveanpil...

  20. Potential thermoelectric performance from optimization of hole-doped Bi2Se3

    SciTech Connect (OSTI)

    Parker, David S [ORNL; Singh, David J [ORNL

    2011-01-01

    We present an analysis of the potential thermoelectric performance of hole-doped Bi2Se3, which is commonly considered to show inferior room temperature performance when compared to Bi2Te3. We find that if the lattice thermal conductivity can be reduced by nanostructuring techniques (as have been applied to Bi2Te3) the material may show optimized ZT values of unity or more in the 300 - 500 K temperature range and thus be suitable for cooling and moderate temperature waste heat recovery and thermoelectric solar cell applications. Central to this conclusion are the larger band gap and the relatively heavier valence bands of Bi2Se3.

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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...

  3. 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

    2007-03-23

    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.

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 ("Tonton Liben...") ki pare ti liv sa a. H ^ AYITI SE PEP AYISYEN 2 0 0 0 Enstiti Etid Ayisyen - Inivesite Kannzas Bon Nouvel Fondasyon Alfa Lwes 2000 PM 7854 .H39 A56 2000 v. 15 YON KONTRA AK LEDJAB Vwala te gen yon malerez ki te deja gen douz pitit, e...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 5 Se Bryant Freeman ("Tonton Liben.... Tijo we yon tig ki te tonbe nan yon gwo twou. Li pa t kapab soti paske twou a fon. Kounye a tig la prizonye. Li di Tijo: "Ou se yon bon ti gason, ede m soti, souple." Tijo reponn: "Si mwen retire ou nan twou a, ou ap manje m." Tig la di: "O non...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 ("Tonton Liben...") ki pare ti liv sa a. AYITI SE PEP AYISYEN Enstiti Etid Ayisyen - Inivesite Kannzas Bon Nouvel Fondasyon Alfa Lwes 2000 PM 7854 • H39 A56 KUAN POU M JWENN KOB? Vwala te gen yon zarenyen ki te raze net. Li di nan tet li: "M bezwen jwenn kob...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    ofisye yo. Genyen yon gwo pyano pou nou pote nan sal la." Pye Wolen, Senlwidino TET DESALIN Yon blan rantre an Ayiti. Li mande yon neg: "Fe m jwenn tet Jan Jak Desalin, pou souvni." Neg la, sa li gen pou fe, li rantre nan yon simitye, li pran yon... tet byen vit. Li pote I bay blan an. Blan an di konsa: "Sa a pa tet Desalin. Tet Desalin pa kapab piti konsa." Neg la di: "Sa a se tet Desalin le I te timoun!" 8 MANGO A Ml Se Bouki ak Malis ki t ap pwonmennen. Bouki di Malis: "Men yon pye mango...

  8. Method of fabricating high-efficiency Cu(In,Ga)(SeS).sub.2 thin films for solar cells

    DOE Patents [OSTI]

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

    1995-01-01

    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.

  9. 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.

    1995-08-15

    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.

  10. Analysis of chemically deposited CdSe and CdS thin films

    E-Print Network [OSTI]

    Osuji, R U

    2002-01-01

    We have successfully deposited quality polycrystalline thin films of CdSe and CdS on Corning 7059 glass slides by the electroless chemical bath technique at room temperature (~27 $^\\circ$C). X-ray analysis confirmed the successful deposition of CdSe and CdS thin films. Our grown CdSe film thickness ranged from 0.10 $\\mu$m. to 0.80 $\\pm$ 0.01 $\\mu$m and the CdS film thickness ranged from 0.10 $\\mu$m to 1.00 $\\pm$ 0.01 $\\mu$m. The scanning electron micrograph of the films reveals uniform film surface. The energy gaps, $E_g$ determined for our CdSe and CdS films have average values of 1.70 $\\pm$ 0.04 eV and 2.15 $\\pm$ 0.04 eV respectively. The films have high absorbance in the 0.35 $\\mu$m - 0.85 $\\mu$m range. These qualities make them suitable for use in thin film solar cell technology.

  11. DISTRIBUTED POSE AVERAGING IN CAMERA NETWORKS VIA CONSENSUS ON SE(3) Roberto Tron, Rene Vidal

    E-Print Network [OSTI]

    DISTRIBUTED POSE AVERAGING IN CAMERA NETWORKS VIA CONSENSUS ON SE(3) Roberto Tron, Ren´e Vidal distributed algorithms for esti- mating the average pose of an object viewed by a localized network of camera networks; pose estimation; consensus; optimization on manifolds. 1. INTRODUCTION Recent hardware

  12. SE-LEGO: Creating Metasearch Engines on Demand Zonghuan Wu, Vijay Raghavan,

    E-Print Network [OSTI]

    Meng, Weiyi

    SE-LEGO: Creating Metasearch Engines on Demand Zonghuan Wu, Vijay Raghavan, Chun Du, Komanduru Sai Keywords: Metasearch Engine, Metasearcher, search engine Extended Abstract As a system that provides unified access to multiple existing search systems, a metasearch engine can alleviate ordinary users from

  13. Long FRC Equilibrium and Stability Toward a Theory of S*/E Scaling D. C. Barnes*

    E-Print Network [OSTI]

    Washington at Seattle, University of

    Long FRC Equilibrium and Stability ­ Toward a Theory of S*/E Scaling D. C. Barnes* Los Alamos-reversed configurations (FRC's) is solved by an expansion in the small parameter (inverse elongation). The main results, to appear Phys. Plasmas]; 2) there are two classes of potentially unstable modes, transverse and axial, both

  14. T-558: Oracle Java SE and Java for Business Critical Patch Update Advisory- February 2011

    Broader source: Energy.gov [DOE]

    This Critical Patch Update contains 21 new security fixes for Oracle Java SE and Java for Business. 19 of these vulnerabilities may be remotely exploitable without authentication, i.e., may be exploited over a network without the need for a username and password.

  15. T-641: Oracle Java SE Critical Patch Update Advisory- June 2011

    Broader source: Energy.gov [DOE]

    This Critical Patch Update contains 17 new security fixes for Oracle Java SE - 5 apply to client and server deployments of Java SE, 11 apply to client deployments of Java SE only, and 1 applies to server deployments of Java SE only. All of these vulnerabilities may be remotely exploitable without authentication, i.e., may be exploited over a network without the need for a username and password. Oracle CVSS scores assume that a user running a Java applet or Java Web Start application has administrator privileges (typical on Windows). Where the user does not run with administrator privileges (typical on Solaris and Linux), the corresponding CVSS impact scores for Confidentiality, Integrity, and Availability are "Partial" instead of "Complete", and the corresponding CVSS Base score is 7.5 instead of 10 respectively. For issues in Deployment, fixes are only made available for JDK and JRE 6. Users should use the Java Web Start in JRE 6 and the new Java Plug-in introduced in 6 Update 10. CVE-2011-0862, CVE-2011-0873, CVE-2011-0815, CVE-2011-0817, CVE-2011-0863, CVE-2011-0864, CVE-2011-0802, CVE-2011-0814, CVE-2011-0871, CVE-2011-0786, CVE-2011-0788, CVE-2011-0866, CVE-2011-0868, CVE-2011-0872, CVE-2011-0867, CVE-2011-0869, and CVE-2011-0865

  16. 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

  17. R. Bchela,b, S.E. Pratsinisa, A. Baikerb Two-Nozzle Flame Synthesis of

    E-Print Network [OSTI]

    Daraio, Chiara

    R. Büchela,b, S.E. Pratsinisa, A. Baikerb Two-Nozzle Flame Synthesis of NOx Storage- Reduction and Bioengineering , ETH Zurich, CH-8092 Zurich, Switzerland NOx storage reduction (NSR) catalysts are used) the corresponding light-off Particle production NOx storage and reduction Objective 0 20 40 60 80 100 3) after

  18. Oceanography Vol.19, No. 3, Sept. 200664 Oceanography Vol.19, No. 3, Se64 Currents, Eddies,

    E-Print Network [OSTI]

    Rhode Island, University of

    Oceanography Vol.19, No. 3, Sept. 200664 Oceanography Vol.19, No. 3, Se64 Currents, Eddies. For a comprehensive re- view of the circulation in the region, see Chang et al. (2004). Oceanography Vol.19, No. 3 ThisarticlehasbeenpublishedinOceanography,Volume19,Number3,aquarterlyjournalofTheOceanographySociety.Copyright2006byTheOceanography

  19. 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, J are reported. Photovoltaic spectra are fitted with measured values oftransport and optical parameters. In possibilities as a material for photovoltaic cells. Transport in indium selenide shows a large ani- sotropy

  20. El tratamiento con cloro es un mtodo para desinfectar un pozo de agua. Se recomien-

    E-Print Network [OSTI]

    El tratamiento con cloro es un método para desinfectar un pozo de agua. Se recomien- da cuando un sistema de agua está contam- inado con bacterias. La contaminación puede ocurrir en la instalación del exceso de lluvia entran en el pozo. Si el agua subterránea constituye en sí la fuente de bacterias, el

  1. Al tratamiento del agua potable para mejo-rar su sanidad o calidad bacteriolgica se

    E-Print Network [OSTI]

    Al tratamiento del agua potable para mejo- rar su sanidad o calidad bacteriológica se le refiere desinfección usado por los proveedores locales para disminuir la contami- nación bacteriológica del agua. Este método tam- bién puede ser usado por los propietarios de pozos de agua particulares. Pozos de agua Los

  2. Molecular beam epitaxial growth of Bi{sub 2}Se{sub 3} nanowires and nanoflakes

    SciTech Connect (OSTI)

    Knebl, G. M. Gessler, J. R.; Kamp, M.; Höfling, S.

    2014-09-29

    Topological Insulators are in focus of immense research efforts and rapid scientific progress is obtained in that field. Bi{sub 2}Se{sub 3} has proven to be a topological insulator material that provides a large band gap and a band structure with a single Dirac cone at the ?-point. This makes Bi{sub 2}Se{sub 3} one of the most promising three dimensional topological insulator materials. While Bi{sub 2}Se{sub 3} nanowires and nanoflakes so far were fabricated with different methods and for different purposes, we here present the first Bi{sub 2}Se{sub 3} nanowires as well as nanoflakes grown by molecular beam epitaxy. The nanostructures were nucleated on pretreated, silicon (100) wafers. Altering the growth conditions nanoflakes could be fabricated instead of nanowires; both with high crystalline quality, confirmed by scanning electron microscopy as well as transmission electron microscopy. These nanostructures have promise for spintronic devices and Majorana fermion observation in contact to superconductor materials.

  3. Stability of S and Se induced reconstructions on GaP(001)(2×1) surface

    SciTech Connect (OSTI)

    Li , D. F.; Guo, Zhi C.; Xiao, Hai Yan; Zu, Xiaotao T.; Gao, Fei

    2010-10-15

    The structural and electronic properties of S- and Se- passivated GaP(001)(2×1) surfaces were studied using first-principles simulations. Our calculations showed that the most stable structure consists of a single chalcogen atom (S or Se) in the first crystal layer, which is bonded to two Ga atoms of the second layer, and the third P layer replaced by chalcogen atoms, similar to the passivation of GaAs(001)(2×1) surface by chalcogen atoms. The structural parameters were determined and the surface band characters and the local density of states were also analyzed. The results showed that the preferable structure has no surface states in the bulk band gap, but the energy band gaps of the S- and Se-adsorbed GaP(001) surfaces are 1.83eV and 1.63eV, respectively. The passivation effects for the S- and Se-adsorbed surfaces are similar to each other.

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

    E-Print Network [OSTI]

    Cao, Guozhong

    , suffer from high cost of manufacturing and installation. Now the focus is on next generation solar cellsA 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

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

    E-Print Network [OSTI]

    Rockett, Angus

    Diffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells O. Lundberga,*, J. Lua , A 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 depth

  6. Tetrapod localities from the Triassic of the SE of European Russia Valentin P. Tverdokhlebova

    E-Print Network [OSTI]

    Benton, Michael

    of the southern Urals area of European Russia. The first sites were found in the 1940s, and subsequent surveys B.V. All rights reserved. Keywords: Permian; Triassic; Tetrapod; Amphibian; Reptile; Russia; UralsTetrapod localities from the Triassic of the SE of European Russia Valentin P. Tverdokhlebova

  7. The Single Most Polymorphic STR Locus: SE33 Performance in U.S. Populations

    E-Print Network [OSTI]

    http://www.cstl.nist.gov/biotech/strbase john.butler@nist.gov http://www.dna.gov/research/nist Buenos of the SE33 repeat region. Poster available for download from STRBase: http://www.cstl.nist.gov/biotech Biotech, Ft. Lauderdale, FL). A total of 400 father-son sample pairs were provided by DNA Diagnostics

  8. 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 of this paper is to investigate the properties of a clinical FFDM unit (Giotto - Image MD, IMS Italy µm. The direct conversion of X-rays into charge provides excellent imaging performance. In this work

  9. U .Se Weather Bureau. Hurricane Daisy, September 30-October 7, 1062

    E-Print Network [OSTI]

    QC 945.2 U .Se Weather Bureau. Hurricane Daisy, September 30- October 7, 1062 #12;National Oceanic and Atmospheric Administration Weather Bureau Hurricane Series ERRATA NOTICE One-1387 November 6,2007 #12;OF COMMERCE WEATHER BUREAU LlBRARY JUL 0 5 2001 121 533 #12;HURRICANE DAISY SEPTEMBER

  10. 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

  11. Oceanography Vol.23, No.124 MouNtaiNs iN the se a

    E-Print Network [OSTI]

    Sandwell, David T.

    Oceanography Vol.23, No.124 MouNtaiNs iN the se a The Global seamount Census By Pau l We s sel , DaVi estimates for the global census of seamounts. BathyMetriC seaMouNt stuDies Bill Menard began the modern era

  12. Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma,

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Se-related blue emission (410 and 435 nm), Zn-related defect state green emission (520 nm), and Mn-dopant related for the purpose of generation of photometrically high quality white light while maintaining the energy efficiency is to combine red-, green-, and blue-emitting NCs in an appropriate ratio.1,2 However, when one simply mixes

  13. 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. Electronic band structure 1. Introduction The TiFe alloy is an excellent material for hydrogen storage [1

  14. SE-CSE 2009: The Second International Workshop on Software Engineering for Computational Science and Engineering

    E-Print Network [OSTI]

    Carver, Jeffrey C.

    SE-CSE 2009: The Second International Workshop on Software Engineering for Computational Science with the development of Computational Science & Engineering (CS&E) software. This software includes: 1) Scientific, the development of CS&E software has historically attracted little attention from the software engineering

  15. MAE 130A / SE 101A (4 units) Mechanics I: Statics

    E-Print Network [OSTI]

    Fainman, Yeshaiahu

    MAE 130A / SE 101A (4 units) Mechanics I: Statics Class/Laboratory Schedule: four hours of lecture/Materials: 1. Beer and Johnston, Vector Mechanics for Engineers - Statics, McGraw-Hill, 2012, 10th ed. 2. Hibbeler, R.C., "Engineering Mechanics: Statics", Pearson Prentice Hall, 2010, 12th ed. Catalog Description

  16. Statistical Mechanics, CHEM 6481, Fall MWF 10:05-10:55am, MoSE 1224

    E-Print Network [OSTI]

    Sherrill, David

    Statistical Mechanics, CHEM 6481, Fall MWF 10:05-10:55am, MoSE 1224 Course website: T-Square Prerequisites: Advanced quantum mechanics (can be taken concurrently), advanced thermodynamics, multivariate" are considered background material. Required Text: "Introduction to Modern Statistical Mechanics," David Chandler

  17. 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

  18. Crystal structure of the new FeSe1-x superconductor 

    E-Print Network [OSTI]

    Margadonna S.; McDonald M.T.; Kasperkiewicz K.; Mizuguchi Y.; Takano Y.; Fitch A.N.; Suard E.; Prassides K.; Takabayashi Y.

    2008-01-01

    The newly discovered superconductor FeSe1-x (x approximate to 0.08, T-c(onset) approximate to 13.5 K at ambient pressure rising to 27 K at 1.48 GPa) exhibits a structural phase transition from tetragonal to orthorhombic ...

  19. Se cumple la regla de Hamilton? Cuando Charles Darwin propuso la teora de la evo-

    E-Print Network [OSTI]

    Machado, Carlos A.

    de reproducirse. En la naturaleza abundan las muestras de altruismo. Pensemos, por ejemplo, en los parentesco ("kin selection"). Esta tesis la esbozó, a mediados de los años se- senta, William Donald Hamilton reducción de comportamientos agre- sivos o de competencia entre congéneres. El núcleo central de dicha tesis

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

    E-Print Network [OSTI]

    Li, Jing

    Mn-Substituted Inorganic-Organic Hybrid Materials Based on ZnSe: Nanostructures That May Lead research that deals with synthesis, characterization, and modification of organic-inorganic hybrid to integrate functional materials that utilize both electron charge and spin.1 Thus, the introduction

  1. Electronic structure of the Si(111):GaSe van der Waals-like surface termination

    E-Print Network [OSTI]

    Olmstead, Marjorie

    Electronic structure of the Si(111):GaSe van der Waals-like surface termination Reiner Rudolph-like surface termination has been determined by angle-resolved photoelectron spectroscopy using photons. This explains both the absence of a surface core-level shift in Si 2p photoelectron spectra of the terminated

  2. Deformation regime variations in an arcuate transpressional orogen (Ribeira belt, SE Brazil) imaged by anisotropy of

    E-Print Network [OSTI]

    Bascou, Jérôme

    Deformation regime variations in an arcuate transpressional orogen (Ribeira belt, SE Brazil) imaged Paulo, Brazil b Laboratoire de Tectonophysique, Universite´ de Montpellier II CNRS, Montpellier, France Instituto de Geocie^ncias, Universidade Federal de Minas Gerais, Minas Gerais, Brazil Received 23 September

  3. Holocene tephra from Iceland and Alaska in SE Greenland Shelf Sediments

    E-Print Network [OSTI]

    Stoner, Joseph

    Holocene tephra from Iceland and Alaska in SE Greenland Shelf Sediments ANNE JENNINGS1*, THORVALDURJW, UK 3 Faculty of Earth Sciences, University of Iceland, Askja, Sturlugata 7, Reykjavi´k 101, Iceland 4 College of Earth Ocean and Atmospheric Sciences, Oregon State University 104 COAS Admin Building

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

    E-Print Network [OSTI]

    Chen, Jixin

    2011-08-08

    by these techniques include the metal nanoparticle arrays, and the self-assembled CdSe nanoring arrays. At the same time, the dissertation provides mechanisms and models to describe the physical and chemical nature of these techniques. The second area of this study...

  5. Summary for FT, IT and SE 20th IAEA Fusion Energy Conference

    E-Print Network [OSTI]

    Summary for FT, IT and SE 20th IAEA Fusion Energy Conference 1 - 6 November 2004 Vilamoura on Plasma Physics and controlled Nuclear Fusion Research has been changed to be IAEA Fusion Energy and should be moved to the ultimat goal of utilizing fusion energy for human being in near future

  6. MAE 130C / SE 101C (4 units) Mechanics III: Vibrations

    E-Print Network [OSTI]

    Fainman, Yeshaiahu

    MAE 130C / SE 101C (4 units) Mechanics III: Vibrations Class/Laboratory Schedule: four hours Textbooks/Materials: 1. S.S. Rao: Mechanical Vibrations, 4th ed., Prentice Hall, 2010 2. W.T. Thomson and M.D. Dahleh, Theory of Vibrations with Applications, 5th ed., Prentice Hall, 1997 3. L. Meirovitch

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

    E-Print Network [OSTI]

    Firestone, Jeremy

    Cu(In,Ga)Se2­based Photovoltaics: Challenges and Opportunities William Shafarman Institute of Energy Conversion University of Delaware #12;Thin Film Photovoltaics Potential for low cost PV using a Thickness K.Kim, et al., IEEE J. Photovoltaics, 3, 446 (2013). 2 µm, 60 min reaction 1 µm, 25 min reaction 0

  8. Contractional deformation of porous sandstone: Insights from the Aztec Sandstone, SE Nevada, USA

    E-Print Network [OSTI]

    Fossen, Haakon

    Contractional deformation of porous sandstone: Insights from the Aztec Sandstone, SE Nevada, USA Available online 19 March 2015 Keywords: Sevier thrusting Porous sandstone deformation Deformation bands Contractional deformation a b s t r a c t Contractional deformation of highly porous sandstones is poorly

  9. 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

  10. Manufacturable CuIn(Ga)Se{sub 2}-based solar cells via development of co-sputtered CuInSe{sub 2} absorber layers

    SciTech Connect (OSTI)

    Dr. Ingrid Eisgruber

    1999-03-20

    Yield and reproducibility remain issues in CuIn(Ga)Se{sub 2} (CIGS) photovoltaic module fabrication. While small-area cells (<1 cm{sup 2}) over 18% efficient have been reported, the best large-area manufactured devices (>1 ft{sup 2}) are 11% efficient with about 60% yield. If improvements in large-area manufacturing can accomplish 15% efficiency and 90% yield, the result is a doubling in throughput leading to a reduction in cost per watt of over 50%. The challenge now facing the photovoltaics industry is to bring the efficiencies of small-area cells and large-area industrial modules closer together and to raise manufacturing yields.

  11. 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

  12. 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

    2015-01-01

    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.

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    la. Ti nonm Ian pa souke ko I tou. Wa a mete de men nan tet pou I rele. Konsa Wa a fe yo pran Malis, yo mete I nan yon sak, yo pandye I nan yon pyebwa annatandan yo voye I nan lanme. Malis t ap kalkile kisa pou I ta fe pou I chape, le de vole...." De vole yo tire oso, e se vole ki pi malen an ki antre nan sak la. Se konsa Malis rive chape anko. Sa gen kek jou depi yo te voye sak la nan lanme. Wa a t ap fe yon pwomnad, li pase devan kay Malis. Le I voye je I nan lakou a, sezisman manke touye...

  14. Yrast studies of {sup 80,82}Se using deep-inelastic reactions

    SciTech Connect (OSTI)

    Jones, G. A.; Regan, P. H.; Podolyak, Zs.; Gelletly, W.; Langdown, S. D. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Yoshinaga, N. [Department of Physics, Saitama University, Saitama City 338-8570 (Japan); Higashiyama, K. [Department of Physics, Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan); De Angelis, G.; Gadea, A.; Axiotis, M.; Kroell, Th.; Marginean, N.; Martinez, T.; Napoli, D. R.; Tonev, D. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Legnaro (Italy); Zhang, Y. H. [Institute of Modern Physics, CAS, Lanzhou (China); Ur, C. A.; Bazzacco, D.; Farnea, E.; Lenzi, S. [INFN Sezione di Padova (Italy)] (and others)

    2007-11-15

    We report the results of an experiment in which we studied the near-yrast states in selenium isotopes approaching N=50 following their population in multinucleon transfer reactions between a {sup 82}Se beam and a {sup 192}Os target. The level schemes for {sup 80,82}Se derived from the current work are compared with restricted-basis shell-model calculations and pair-truncated shell-model calculations. These provide a good description of the yrast sequences in these nuclei using a basis space limited to excitations in the {nu}(p{sub (3/2)},p{sub (1/2)},g{sub (9/2)}) and {pi}(f{sub (5/2)},p{sub (3/2)},p{sub (1/2)}) orbitals.

  15. 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)

    2014-03-24

    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.

  16. 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.

    2012-09-01

    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.

  17. Statistical Mechanics of Disordered Systems, SoSe 2005 Timo Aspelmeier, Alexander K. Hartmann, Universitat Gottingen

    E-Print Network [OSTI]

    Hartmann, Alexander K.

    Statistical Mechanics of Disordered Systems, SoSe 2005 Timo Aspelmeier, Alexander K. Hartmann reserach! Statistics: most people leave our offices alive. Homepage: http://www.theorie.physik.uni-goe.de/~hartmann://www.theorie.physik.uni-goe.de/~aspel Alexander K. Hartmann Office A4.108 Phone +49-(0)551 39 5995 hartmann@physik.uni-goettingen.de http://www.theorie.physik.uni-goe.de/~hartmann

  18. Multinucleon Transfer Reactions to Study Single-Particle Evolution in Se Isotopes

    SciTech Connect (OSTI)

    Regan, P. H.; Jones, G. A.; Podolyak, Zs.; Gelletly, W.; Langdown, S. D. [Dept. of Physics, School of Electronics and Physical Sciences, Guildford, Surrey, UK (United Kingdom); Yoshinaga, N. [Department of Physics, Saitama University, Saitama City, 338-8570 (Japan); Higashiyama, K. [Department of Physics, University of Tokyo, Hongo, Tokyo, 113-0033 (Japan); De Angelis, G.; Gadea, A.; Axiotis, M.; Kroell, Th.; Marginean, N.; Martinez, T.; Napoli, D. R.; Rusu, C.; Tonev, D. [INFN Laboratori Nazionali di Legnaro, Legnaro (Italy); Zhang, Y. H. [INFN Laboratori Nazionali di Legnaro, Legnaro (Italy); Institute of Modern Physics, CAS, Lanzhou (China); Ur, C. A.; Bazzacco, D.; Farnea, E. [INFN, Sezione di Padova, Padova (Italy)] (and others)

    2006-03-13

    This contribution reports on the results of an experiment to study the near-yrast states in selenium isotopes around N=50, following their population in thick-target, multinucleon transfer reactions between an 82Se beam and a 192Os target. Discrete decays from states with spins of 20({Dirac_h}/2{pi}) and higher are clearly identified in the Os-like fragments. Information on the size of the energy gap between the f5/2 and p3/2 proton orbitals can be inferred from the spectroscopy of the N=48 isotone, 82Se. The experiment results for the level schemes for 80,82Se derived in the current work are compared with restricted-basis shell model calculations, which give a good description of the yrast sequences of these nuclei using a basis space limited to excitations in the (p3/2, p1/2, g9/2) neutron and (f5/2, p3/2, p1/2 ) proton orbitals.

  19. Blue and green electroluminescence from CdSe nanocrystal quantum-dot-quantum-wells

    SciTech Connect (OSTI)

    Lu, Y. F.; Cao, X. A.

    2014-11-17

    CdS/CdSe/ZnS quantum dot quantum well (QDQW) nanocrystals were synthesized using the successive ion layer adsorption and reaction technique, and their optical properties were tuned by bandgap and strain engineering. 3-monolayer (ML) CdSe QWs emitted blue photoluminescence at 467?nm with a spectral full-width-at-half-maximum of ?30?nm. With a 3 ML ZnS cladding layer, which also acts as a passivating and strain-compensating layer, the QDQWs acquired a ?35% quantum yield of the QW emission. Blue and green electroluminescence (EL) was obtained from QDQW light-emitting devices with 3–4.5 ML CdSe QWs. It was found that as the peak blueshifted, the overall EL was increasingly dominated by defect state emission due to poor hole injection into the QDQWs. The weak EL was also attributed to strong field-induced charge separation resulting from the unique QDQW geometry, weakening the oscillator strength of optical transitions.

  20. Extending the roads for survival: An ethnography of the ongoing Maya Diaspora

    E-Print Network [OSTI]

    Bazua Morales, Carlos Miguel

    2013-01-01

    de Migración y Desarrollo. Archdiocese of Guatemala 1999.Guatemala: Never Again!Archdiocese of Guatemala. New York: Orbis Books. Arias,

  1. Deep divergences and extensive phylogeographic structure in a clade of lowland tropical salamanders

    E-Print Network [OSTI]

    Rovito, Sean M; Parra-Olea, Gabriela; Vásquez-Almazán, Carlos R; Luna-Reyes, Roberto; Wake, David B

    2012-01-01

    Bolitoglossa hartwegi Guatemala Bolitoglossa rufescenskm W Berriozabal B. rufescens Guatemala: Huehuetenango SigloBarillas B. rufescens Guatemala: Huehuetenango Las Victorias

  2. X-ray irradiation induced changes in electron transport in stabilized a-Se photoconductors

    SciTech Connect (OSTI)

    Walornyj, M.; Kasap, S. O.

    2013-12-07

    We have examined the effect of high-dose x-ray irradiation on electron transport in stabilized amorphous selenium (a-Se) x-ray photoconductive films (of the type used in x-ray image detectors) by measuring the electron lifetime ?{sub e} through interrupted-field time-of-flight experiments. X-ray induced effects have been examined through two types of experiments. In recovery experiments, the a-Se was preirradiated with and without an applied field (5 V/?m) during irradiation with sufficient dose (typically ?20 Gy at 21 °C) to significantly reduce the electron lifetime by ?50%, and then the recovery of the lifetime was monitored as a function of time at three different temperatures, 10 °C, 21 °C, and 35 °C. The lifetime recovery kinetics was exponential with a relaxation time ?{sub r} that is thermally activated with an activation energy of 1.66 eV. ?{sub r} is a few hours at 21 °C and only a few minutes at 35 °C. In experiments examining the irradiation induced effects, the a-Se film was repeatedly exposed to x-ray radiation and the changes in the drift mobility and lifetime were monitored as a function of accumulated dose D. There was no observable change in the drift mobility. At 21 °C, the concentration of x-ray induced deep traps (or capture centers), N{sub d}, increases linearly with D (N{sub d} ? D) whereas at 35 °C, the recovery process prevents a linear increase in N{sub d} with D, and N{sub d} saturates. In all cases, even under high dose irradiation (?50 Gy), the lifetime was recoverable to its original equilibrium (pre-exposure) value within a few relaxation times.

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

    E-Print Network [OSTI]

    Bryant, John Duffie

    1972-01-01

    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...

  4. Structural and optical studies on AgSbSe{sub 2} thin films

    SciTech Connect (OSTI)

    Asokan, T. Namitha; Urmila, K. S.; Pradeep, B. [Solid State Physics Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi- 22, Kerala (India)

    2014-01-28

    AgSbSe{sub 2} semiconducting thin films are successfully deposited using reactive evaporation technique at a substrate temperature of 398K. X-ray diffraction studies reveal that the films are polycrystalline in nature. The structural parameters such as average particle size, dislocation density, and number of crystallites per unit have been evaluated. Atomic Force Microscopy is used to study the topographic characteristics of the film including the grain size and surface roughness. The silver antimony selenide thin films have high absorption coefficient of about 10{sup 5} cm{sup ?1} and it has an indirect band gap of 0.64eV.

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    KU ScholarWorks | http://kuscholarworks.ku.edu Ann Bay Lodyans 12 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 EPI BONDYE KREYE PREMYE FS A Nan...

  7. Determination of the Exciton Binding Energy in CdSe Quantum Dots

    SciTech Connect (OSTI)

    Meulenberg, R; Lee, J; Wolcott, A; Zhang, J; Terminello, L; van Buuren, T

    2009-10-27

    The exciton binding energy (EBE) in CdSe quantum dots (QDs) has been determined using x-ray spectroscopy. Using x-ray absorption and photoemission spectroscopy, the conduction band (CB) and valence band (VB) edge shifts as a function of particle size have been determined and combined to obtain the true band gap of the QDs (i.e. without and exciton). These values can be compared to the excitonic gap obtained using optical spectroscopy to determine the EBE. The experimental EBE results are compared with theoretical calculations on the EBE and show excellent agreement.

  8. ScanningTunneling Luminescence of Grain Boundaries in Cu(In,Ga)Se2

    SciTech Connect (OSTI)

    Romero, M. J.; Jiang, C.-S.; Al-Jassim, M. M.; Noufi, R.

    2005-01-01

    At the Laboratory, photon emission in semiconductors has been mapped in the nanoscale using scanning tunneling microscopy (STM). In this Solar Program Review Meeting, we report on the latest results obtained in Cu(In,Ga)Se2 (CIGS) thin films by this adapted STM. Scanning tunneling luminescence (STL) spectroscopy suggests that photons are emitted near the surface of CIGS. STL is excited either by (1) diffusion of tunneling electrons and subsequent recombination with available holes in CIGS or (2) impact ionization by hot electrons. Which process becomes predominant depends on the voltage applied to the STM tip. Photon mapping shows electronically active, extended defects near the surface of CIGS thin films.

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 MARYAJ MALIS TWOUKOUKOU Vwala se Malis ki gen yon sel... rantre nan chanm Ian ak yon lanp. Yo gade, epi yo we moun ak mouchwa wouj la. Yo peze kou moun ak foula a jous li toufe, epi yo ale. Nan denmen maten, Malis leve. L al di yo: "Mezanmi, mesi anpil. M gen lontan m pa gen yon bon nwit kon sa...

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

    E-Print Network [OSTI]

    Freeman, Bryant C.

    2000-01-01

    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 YON TOTI K AP CHANTE Vwala te gen yon neg yo rele... Gwoje. Msye te konn plante diri. Chak ane li pa janm ka fe bon rekot. Bet yo pran tout plezi yo nan manje jaden diri a. Se konsa, Gwoje blije mete veye pou trape vole k ap depafini jaden I la. Yon jou, pandan Pijon ak Kanna ap soti pou al nan jaden...

  11. 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

    2013-01-01

    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.

  12. 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.

    2011-12-28

    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”).

  13. Flow of US/SE Program Funding to National Laboratories (FY 2014 Enacted) |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergy A plug-inPPLforLDRD Report toDepartment of Energy Figure 4.2: Flow of US/SE

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

    E-Print Network [OSTI]

    Sites, James R.

    , it is important that red-light J-V of CIS solar cells be distortion-free. It was shown that one approach to reduceDISSERTATION 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

  15. Jornalero: the life and work of Latin American Day Laborers in Berkeley, California

    E-Print Network [OSTI]

    Ordonez, Juan Thomas

    2010-01-01

    and Duplicity in Postwar Guatemala. In Anthropology in theassume that only the guatemalas 6 above Sixth Street wouldtell me how many A guatemala is a person from Guatemala,

  16. 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.

    2015-04-20

    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

  17. Tensile Strain Switched Ferromagnetism in Layered NbS2 and NbSe2

    SciTech Connect (OSTI)

    Zhou, Yungang; Wang, Zhiguo; Yang, Ping; Zu, Xiaotao; Yang, Li; Sun, Xin; Gao, Fei

    2012-11-01

    Developing approaches to effectively induce and control the magnetic states is critical to the use of magnetic nanostructures in quantum information devices but is still challenging. Here we have demonstrated, by employing the density functional theory calculations, an existence of infinite magnetic sheets with structural integrity and magnetic homogeneity. Examination from a series of transition metal dichalcogenides shows that the biaxial tensile strained NbS2 and NbSe2 structures can be magnetized with a ferromagnetic character due to the competitive effects of through-bond interaction and through-space interaction. The estimated Curie temperatures (387 and 542 K under the 10% strain for NbS2 and NbSe2 structures, respectively) suggest that the unique ferromagnetic character can be achieved above room temperature. The self-exchange of population between 4d orbitals of Nb atom that leads to the exchange splitting is the mechanism behind the transition of the spin moment. The induced magnetic moments can be significantly enhanced by the tensile strain, even giving rise to half-metallic character with the strong spin polarization around the Fermi level. Given the recent progress that the desired strain can be achieved on two-dimensional nanostructures, such as graphene and BN layer in a controlled way, we believe that our calculated results are suitable for experimental verification and implementation opening a new path to explore the spintronics in pristine two-dimensional nanostructures.

  18. Dependence of superconductivity in CuxBi2Se3 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.

    2015-04-20

    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. Thus, 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

  19. 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.

    2015-03-17

    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

  20. First observation of temperature dependent lightinduced response of Ge25As10Se65 thin films

    E-Print Network [OSTI]

    Khan, Pritam; Deshpande, Uday; Adarsh, K V

    2015-01-01

    Ge rich ternary chalcogenide glasses (ChG) exhibit photobleaching (PB) when illuminated with bandgap light and such an effect is originating from the combined effect of intrinsic structural changes and photo-oxidation. In a sharp contradict to these previous observations, in this letter, we demonstrate for the first time that Ge rich Ge25As10Se65 ChG thin films exhibit photodarkening (PD) at 20 K and PB at 300 and 420 K for continuous illumination of ~ 3 hours. Strikingly, the temporal evolution of PD/PB show distinct characteristics at the temperatures of illumination and provide valuable information on the light induced structural changes. Further, structure specific far infrared (FIR) absorption measurements give direct evidence of different structural units involved in PD/PB at the contrasting temperatures. By comparing the lightinduced effects in vacuum and air, we conclude that intrinsic structural changes dominate over photo-oxidation in the observed PB in Ge25As10Se65 ChG thin films.

  1. Polytypism, polymorphism, and superconductivity in TaSe2–xTex

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

    Luo, Huixia; Xie, Weiwei; Tao, Jing; Inoue, Hiroyuki; Gyenis, András; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, Robert Joseph

    2015-03-03

    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. Thus, 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

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

    SciTech Connect (OSTI)

    Kilina, Svletana; Sergei, Ivanov A; Victor, Klimov I; Sergei, Tretiak

    2008-01-01

    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.

  3. Electronic Structure of Ligated CdSe Clusters: Dependence on DFT Methodology

    SciTech Connect (OSTI)

    Albert, VV; Ivanov, SA; Tretiak, S; Kilina, SV

    2011-07-07

    Simulations of ligated semiconductor quantum dots (QDs) and their physical properties, such as morphologies, QD-ligand interactions, electronic structures, and optical transitions, are expected to be very sensitive to computational methodology. We utilize Density Functional Theory (DFT) and systematically study how the choice of density functional, atom-localized basis set, and a solvent affects the physical properties of the Cd{sub 33}Se{sub 33} cluster ligated with a trimethyl phosphine oxide ligand. We have found that qualitative performance of all exchange-correlation (XC) functionals is relatively similar in predicting strong QD-ligand binding energy ({approx}1 eV). Additionally, all functionals predict shorter Cd-Se bond lengths on the QD surface than in its core, revealing the nature and degree of QD surface reconstruction. For proper modeling of geometries and QD-ligand interactions, however, augmentation of even a moderately sized basis set with polarization functions (e.g., LANL2DZ* and 6-31G*) is very important. A polar solvent has very significant implications for the ligand binding energy, decreasing it to 0.2-0.5 eV. However, the solvent model has a minor effect on the optoelectronic properties, resulting in persistent blue shifts up to {approx}0.3 eV of the low-energy optical transitions. For obtaining reasonable energy gaps and optical transition energies, hybrid XC functionals augmented by a long-range Hartree-Fock orbital exchange have to be applied.

  4. 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

    2014-01-01

    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.

  5. Postal address School of Industrial Design, LTH, P.O. Box 118, 221 00 Lund, SWEDEN Telephone +46 46 222 71 88 E-mail Lynn.Lindegren@kansli.lth.se Website www.industrialdesign.lth.se

    E-Print Network [OSTI]

    Postal address School of Industrial Design, LTH, P.O. Box 118, 221 00 Lund, SWEDEN Telephone +46 46 222 71 88 E-mail Lynn.Lindegren@kansli.lth.se Website www.industrialdesign.lth.se School of Industrial of Industrial Design autumn semester 2015. Full-time study is 30 credits. Bachelor´s programme ­ 1st term Course

  6. Flowing versus Static Conditions for Measuring Multiple Exciton Generation in PbSe Quantum Dots

    SciTech Connect (OSTI)

    Midgett, Aaron G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States); Hillhouse, Hugh W. [Univ. of Washington, Seattle, WA (United States); Hughes, Barbara K. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States); Nozik, Arthur J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States); Beard, Matthew C. [Univ. of Colorado, Boulder, CO (United States)

    2010-09-22

    Recent reports question the validity of pulsed fs-laser experiments for measuring the photon-to-exciton quantum yields (QYs) that result from multiple exciton generation (MEG). The repetitive nature of these experiments opens up an alternative relaxation pathway that may produce artificially high results. We present transient-absorption (TA) data for 4.6 and 6.6 nm diameter PbSe quantum dots (QDs) at a variety of pump photon energies. The data are collected under laminar flow conditions with volumetric flow rates ranging from 0 to 150 mL/min (resulting in Reynolds numbers up to 460). The results are modeled with a spatially resolved population balance of generation, recombination, convective replacement, and accumulation of long-lived excited QDs. By comparing the simulations and experiments, the steady-state population of the long-lived QD-excited states and their kinetics are determined for different experimental conditions. We also improve upon reported photon-to-exciton QYs for PbSe QDs. We find differences in the observed TA dynamics between flowing and static conditions that depend upon photon fluence, pump photon energy, and quality of the QD surfaces. For excitation energies below 2 Eg, independent of QD size or photon fluence, we observe no flow rate dependence in the TA dynamics. At excitation energies of h? > 3 Eg, we observe differences between static and flowing conditions that are most pronounced for high photon fluences. At 3.7 Eg and for 4.6 nm PbSe QDs we find a QY of 1.2 ± 0.1 and at 4.5 Eg the QY is 1.55 ± 0.05. With 6.6 nm QDs excited at 4.7 Eg we observe no difference between static and flowing conditions and find a QY of 1.61 ± 0.05. We also find that by treating the surface of QDs, we can decrease the charging probability (Pg ? 5 × 10-5) by a factor of 3-4. The observed variations suggest that different QD samples vary regarding their susceptibility to the creation of long-lived states.

  7. Conduction in Charged PbSe Nanocrystal Films Brian L. Wehrenberg, Dong Yu, Jiasen Ma, and Philippe Guyot-Sionnest*

    E-Print Network [OSTI]

    Yu, Dong

    system for incorporation into solar cells and photodetectors.7-9 The ability to successfully properties of arrays of semiconductor nano- crystals have been studied previously. Arrays of uncharged CdSe was seen to increase by several orders of magnitude.11 At low temperature, the conduction in these CdSe

  8. Crystalline ZnMgSe:Cr2+: a new material for active elements of tunable IR-lasers

    E-Print Network [OSTI]

    Yu. A. Zagoruiko; N. O. Kovalenko; O. A. Fedorenko; V. A. Khristyan

    2008-07-01

    Obtained is a new thermostable material for active elements of tunable IR-lasers - Zn1-xMgxSe:Cr2+ single crystals. The position of the absorption band of Cr2+ ions in wurtzite-type Zn0.8Mg0.2Se matrix is established.

  9. Synthesis of monodispersed CdSe nanocrystals in poly(styrene-alt-maleic anhydride) at room temperature

    SciTech Connect (OSTI)

    Liu, S.H.; Qian, X.F.; Yuan, J.Y.; Yin, J.; He, R.; Zhu, Z.K

    2003-07-14

    Nanocomposite of CdSe/poly(styrene-alt-maleic anhydride) (PSM) was successfully prepared via an in situ reaction process at room temperature and ambient pressure. Transmission electron microscopy (TEM) analysis revealed that CdSe nanoparticles with a small size and narrow size distribution were obtained. The obtained nanocomposite was also characterized by FT-IR, XRD, ultraviolet-visible, and fluorescence spectroscopy.

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

    E-Print Network [OSTI]

    Rockett, Angus

    . They have been shown to yield solar cells with efficiencies greater than 17%, and over time films of group III-rich CuIn1 xGaxSe2 CIGS . The films were produced using a hybrid sputtering interest in renewable energy sources such as photovoltaic devices. CuIn1 xGaxSe2 CIGS /CdS hetero- junction

  11. Approved Module Information for SE4025, 2014/5 Module Title/Name: Further Topics in Engineering

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for SE4025, 2014/5 Module Title/Name: Further Topics in Engineering Management Module Code: SE4025 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 15 Module Management Information Module Leader Name Robin Clark Email Address

  12. 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

  13. Highly efficient nonradiative energy transfer using charged CdSe/ZnS nanocrystals for light-harvesting in solution

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    % in solution. CdTe and CdSe/ZnS dots of different sizes have further been studied for energy trans- fer in filmHighly efficient nonradiative energy transfer using charged CdSe/ZnS nanocrystals for light-harvesting in solution Evren Mutlugün,a Sedat Nizamolu, and Hilmi Volkan Demirb Department of Physics; Department

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

    E-Print Network [OSTI]

    Anderson, Timothy J.

    -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 solar cell have been carried out. A variety of graded band-gap structures, including space charge region

  15. 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

  16. 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)

    2014-09-14

    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}.

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

    DOE Patents [OSTI]

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

    2007-02-20

    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.

  18. Stable N-CuInSe.sub.2 /iodide-iodine photoelectrochemical cell

    DOE Patents [OSTI]

    Cahen, David (Rehovot, IL); Chen, Yih W. (Lakewood, CO)

    1985-01-01

    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.sup.3+ salts.

  19. Co-Evaporated Cu2ZnSnSe4 Films and Devices

    SciTech Connect (OSTI)

    Repins, I.; Beall, C.; Vora, N.; DeHart, C.; Kuciauskas, D.; Dippo, P.; To, B.; Mann, J.; Hsu, W. C.; Goodrich, A.; Noufi, R.

    2012-06-01

    The use of vacuum co-evaporation to produce Cu2ZnSnSe4 photovoltaic devices with 9.15% total-area efficiency is described. These new results suggest that the early success of the atmospheric techniques for kesterite photovoltaics may be related to the ease with which one can control film composition and volatile phases, rather than a fundamental benefit of atmospheric conditions for film properties. The co-evaporation growth recipe is documented, as is the motivation for various features of the recipe. Characteristics of the resulting kesterite films and devices are shown in scanning electron micrographs, including photoluminescence, current-voltage, and quantum efficiency. Current-voltage curves demonstrate low series resistance without the light-dark cross-over seen in many devices in the literature. Band gap indicated by quantum efficiency and photoluminescence is roughly consistent with that expected from first principles calculation.

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

    SciTech Connect (OSTI)

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

    1983-08-01

    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.

  1. Fluorescence modulation in single CdSe quantum dots by moderate applied electric fields

    SciTech Connect (OSTI)

    LeBlanc, Sharonda J. [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); McClanahan, Mason R.; Moyer, Tully; Moyer, Patrick J. [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); Jones, Marcus [Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States)

    2014-01-21

    Single molecule time-resolved fluorescence spectroscopy of CdSe/ZnS core-shell quantum dots (QDs) under the influence of moderate applied electric fields reveals distributed emission from states which are neither fully on nor off and pronounced changes in the excited state decay. The data suggest that a 54?kV/cm applied electric field causes small perturbations to the QD surface charge distribution, effectively increasing the surface trapping probability and resulting in the appearance of gray states. We present simultaneous blinking and fluorescence decay results for two sets of QDs, with and without an applied electric field. Further kinetic modeling analysis suggests that a single trapped charged cannot be responsible for a blinking off event.

  2. Photo-instability of CdSe/ZnS quantum dots in poly(methylmethacrylate) film

    SciTech Connect (OSTI)

    Zhang, Hongyi; Liu, Yu; Ye, Xiaoling; Chen, Yonghai

    2013-12-28

    The photo-instability of CdSe/ZnS quantum dots (QDs) has been studied under varied conditions. We discussed the main features of the evolution of photoluminescence (PL) intensity and energy at different laser powers, which showed critical dependences on the environment. The PL red shift in a vacuum showed strong temperature dependence, from which we concluded that the thermal activation energy for trapping states of the charge carriers was about 14.7 meV. Furthermore, the PL spectra showed asymmetric evolution during the laser irradiation, for which two possible explanations were discussed. Those results provided a comprehensive picture for the photo-instability of the colloidal QDs under different conditions.

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

    SciTech Connect (OSTI)

    Dixit, Shiv Kumar Bhatnagar, Chhavi Kumari, Anita Madhwal, Devinder Bhatnagar, P. K. Mathur, P. C.

    2014-10-15

    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.

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

    DOE Patents [OSTI]

    Cahen, D.; Chen, Y.W.

    1984-09-20

    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.

  5. 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

    2007-10-03

    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.

  6. 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)

    2008-03-21

    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.

  7. 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

    2009-05-26

    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.

  8. SPACES OF SECURITY: INTERROGATING THE GIRL EFFECT IN GUATEMALA

    E-Print Network [OSTI]

    Wehr, Heather

    2014-08-31

    -structured interviews were conducted with young, indigenous Guatemalan women affiliated with an NGO funded by The Girl Effect in an attempt to better understand how NGO knowledge about universal human rights and gender equity is received by program participants...

  9. Oxygen and hydrogen isotopes in thermal waters at Zunil, Guatemala

    SciTech Connect (OSTI)

    Fournier, R.O.; Hanshaw, B.B.; Urrutia Sole, J.F.

    1982-10-01

    Enthalpy-chloride relations suggest that a deep reservoir exists at Zunil with a temperature near 300/sup 0/C. Water from that reservoir moves to shallower and cooler local reservoirs, where it mixes with diluted water and then attains a new water-rock chemical equilibrium. This mixed water, in turn, generally is further diluted before being discharged from thermal springs. The stable-isotopic composition of the thermal water indicates that recharge for the deep water at Zunil comes mainly from local sources. The presence of measurable tritium, which suggests that the deep water has been underground about 20 to 30 years, also indicates a local source for the recharge.

  10. An anthropological view of the forest culture of Peten, Guatemala

    SciTech Connect (OSTI)

    Schwartz, N.B.

    1995-12-31

    Traditional farmers and harvesters of non-timber forest products in Peten treat the forest in ways that conserve and regenerate its resources. They believe no one owns the forest outright. Humans share it with other life forms and therefore no one has the right to monopolize or destroy forest resources. Traditional Peteneros find a use for almost everything in the forest, and believe it neither smart nor proper to use a given area for a single purpose, for example, to clear an area of all trees and devote it exclusively to a cattle pasture. In the traditional system most medicinal plants, basic foodstuffs, fuelwoods and construction materials are taken from the bosque (secondary forests within walking distance of human settlements). Peteneros` sustainable use of bosques eases pressure on the monte (primary forests). In the monte Peteneros` harvesting practices are protective of resources, causing minimal damage. Finding almost everything in the forest useful, Peteneros believe all soils and plants should be tended and allowed to regenerate. However, modern developments such as uncontrolled logging, large-scale, unorganized colonization, cattle raising and market demands leading to monocropped farm plots imperil the forests of Peten and a way of life that subsumes a practical conservation ethic.

  11. Geysering discharge of a geothermal wellbore at Zunil, Guatemala

    SciTech Connect (OSTI)

    Michels, Donald E.

    1991-01-01

    Within two hours after discharge began, for a production test in 1989 of well ZCQ-4, pressure variations changed from approximately sinusoidal to a cycle of sudden and complex peak discharge pressures, to 9 bar, separated by irregular pressure declines to 5 bar. Initial cycle periods of 42 minutes evolved to 150 minutes by day 20 of continuous testing, when three of four surge peaks were well separated. Chemical signatures of fluids discharged with pressure surges were distinctive. When combined with downwell pressure measurements, assignments can be made for elevations of fluid entry points. The variety of chemical signatures indicates a scarcity of interzone connectivity. These constrained discharges are suspected to derive from altered rubble zones between layered volcanic rocks.

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

    Open Energy Info (EERE)

    has established joint EC-LEDS work programs with 13 countries, including Albania, Bangladesh, Colombia, Costa Rica, Gabon, Indonesia, Kenya, Macedonia, Mexico, Moldova, the...

  13. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainableGlynn County,Solar JumpInformationGrowindFunan Bioenergy(RECP) in

  14. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainableGlynn County,Solar JumpInformationGrowindFunan Bioenergy(RECP)

  15. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam: Energy Resources Jump to: navigation, search(EC-LEDS) | Open

  16. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam: Energy Resources Jump to: navigation, search(EC-LEDS) |

  17. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam: Energy Resources Jump to: navigation, search(EC-LEDS)

  18. 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)

    2012-05-15

    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.

  19. 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)

    2014-04-07

    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.

  20. 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)

    2014-04-24

    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.

  1. Effects of competing magnetic interactions on the electronic transport properties of CuCrSe{sub 2}

    SciTech Connect (OSTI)

    Tewari, Girish C.; Jawaharlal Nehru University, New Delhi 110067 ; Karppinen, Maarit; Rastogi, Ashok K.

    2013-02-15

    We have synthesized single-phase samples of the CuCrSe{sub 2} phase that exhibits hexagonal-rhombohedral layered crystal structure with space group R3m. Here we present a detailed study of electronic transport and magnetic properties of CuCrSe{sub 2}. We moreover investigate the heat capacity of CuCrSe{sub 2} in comparison to that of CuCrS{sub 2}. The electrical resistivity of CuCrSe{sub 2} shows metallic-like behavior down to 2 K, while the thermoelectric power is large around 100 {mu}V K{sup -1} at 300 K. A weak anomaly in resistivity and a rounded maximum in magnetic susceptibility are observed around 55 K. No sharp transition at 55 K is observed in the heat capacity of CuCrSe{sub 2}, rather a visible maximum is seen. At low temperatures from 2 to 14 K, the magnetic heat capacity follows T{sup 2}-dependence. We tentatively believe this behavior of CuCrSe{sub 2} to be due to competing magnetic interactions between intralayer Cr atoms. The ferromagnetic Cr-Se-Cr indirect exchange among intralayer Cr atoms is enhanced in the selenide compound (that is more metallic than the sulfide compound), and competes with the antiferromagnetic Cr-Cr direct interactions. The interlayer antiferromagnetic exchange through Cu atoms leads to magnetic ordering at low temperature at T{sub N}=55 K. - Graphical abstract: Comparison of magnetic properties of CuCrSe{sub 2} and CuCrS{sub 2} indicates a sharp cusp-like anomaly in magnetic susceptibility at the antiferromagnetic transition of CuCrS{sub 2} while the maximum of CuCrSe{sub 2} is well rounded. Magnetization is reversible after field-cooling (FC) and zero-field-cooling (ZFC) for both compounds. Highlights: Black-Right-Pointing-Pointer Layered CuCrSe{sub 2} can be synthesized in both fully and partially cation-ordered forms. Black-Right-Pointing-Pointer Contrary to previously believed insulating nature the cation-ordered phase is metallic. Black-Right-Pointing-Pointer Magnetic property of CuCrSe{sub 2} is somewhat different from that of CuCrS{sub 2}. Black-Right-Pointing-Pointer Magnetization and heat capacity data suggest complex short-range ordering for CuCrSe{sub 2}.

  2. 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

    2008-08-06

    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.

  3. 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)

    2013-10-15

    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.

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

    DOE Patents [OSTI]

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

    2003-01-01

    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.

  5. Characterization of Cu(In,Ga)Se2 (CIGS) films with varying gallium ratios

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

    Claypoole, Jesse; Peace, Bernadette; Sun, Neville; Dwyer, Dan; Eisaman, Matthew D.; Haldar, Pradeep; Efstathiadis, Harry

    2015-09-05

    Cu(In1-x,Gax)Se2 (CIGS) absorber layers were deposited on molybdenum (Mo) coated soda-lime glass substrates with varying Ga content (described as Ga/(In+Ga) ratios) with respect to depth. As the responsible mechanisms for the limitation of the performance of the CIGS solar cells with high Ga contents are not well understood, the goal of this work was to investigate different properties of CIGS absorber films with Ga/(In+Ga) ratios varied between 0.29 and 0.41 (as determined by X-ray florescence spectroscopy (XRF)) in order to better understand the role that the Ga content has on film quality. The Ga grading in the CIGS layer hasmore »the effect causing a higher bandgap toward the surface and Mo contact while the band gap in the middle of the CIGS layer is lower. Also, a wider and larger Ga/(In+Ga) grading dip located deeper in the CIGS absorber layers tend to produce larger grains in the regions of the films that have lower Ga/(In+Ga) ratios. It was found that surface roughness decreases from 51.2 nm to 41.0 nm with increasing Ga/(In+Ga) ratios. However, the surface roughness generally decreases if the Ga grading occurs deeper in the absorber layer.« less

  6. The electric dipole response of $^{76}$Se above 4 MeV

    E-Print Network [OSTI]

    P. M. Goddard; N. Cooper; V. Werner; G. Rusev; P. D. Stevenson; A. Rios; C. Bernards; A. Chakraborty; B. P. Crider; J. H. Kelley; E. Kwan; J. Glorius; E. E. Peters; N. Pietralla; R. Raut; C. Romig; D. Savran; L. Schnorrenberger; M. K. Smith; K. Sonnabend; A. P. Tonchev; W. Tornow; S. W. Yates

    2013-06-17

    The dipole response of $^{76}_{34}$Se in the energy range 4 to 9 MeV has been analyzed using a $(\\vec\\gamma,{\\gamma}')$ polarized photon scattering technique, performed at the High Intensity $\\gamma$-Ray Source facility, to complement previous work performed using unpolarized photons. The results of this work offer both an enhanced sensitivity scan of the dipole response and an unambiguous determination of the parities of the observed J=1 states. The dipole response is found to be dominated by $E1$ excitations, and can reasonably be attributed to a pygmy dipole resonance. Evidence is presented to suggest that a significant amount of directly unobserved excitation strength is present in the region, due to unobserved branching transitions in the decays of resonantly excited states. The dipole response of the region is underestimated when considering only ground state decay branches. We investigate the electric dipole response theoretically, performing calculations in a 3D cartesian-basis time-dependent Skyrme-Hartree-Fock framework.

  7. 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.

    2011-07-01

    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.

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

    SciTech Connect (OSTI)

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

    2014-12-23

    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.

  9. 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.

    2014-12-23

    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

  10. Monte Carlo modeling of transport in PbSe nanocrystal films

    SciTech Connect (OSTI)

    Carbone, I. Carter, S. A.; Zimanyi, G. T.

    2013-11-21

    A Monte Carlo hopping model was developed to simulate electron and hole transport in nanocrystalline PbSe films. Transport is carried out as a series of thermally activated hopping events between neighboring sites on a cubic lattice. Each site, representing an individual nanocrystal, is assigned a size-dependent electronic structure, and the effects of particle size, charging, interparticle coupling, and energetic disorder on electron and hole mobilities were investigated. Results of simulated field-effect measurements confirm that electron mobilities and conductivities at constant carrier densities increase with particle diameter by an order of magnitude up to 5?nm and begin to decrease above 6?nm. We find that as particle size increases, fewer hops are required to traverse the same distance and that site energy disorder significantly inhibits transport in films composed of smaller nanoparticles. The dip in mobilities and conductivities at larger particle sizes can be explained by a decrease in tunneling amplitudes and by charging penalties that are incurred more frequently when carriers are confined to fewer, larger nanoparticles. Using a nearly identical set of parameter values as the electron simulations, hole mobility simulations confirm measurements that increase monotonically with particle size over two orders of magnitude.

  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 [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)

    2014-12-01

    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.

  12. Nanoscale chemical phase separation in FeTe0.55Se0.45 as seen...

    Office of Scientific and Technical Information (OSTI)

    DOE PAGES Search Results Publisher's Accepted Manuscript: Nanoscale chemical phase separation in FeTe0.55Se0.45 as seen via scanning tunneling spectroscopy Prev Next Title:...

  13. Selective turn-on fluorescence detection of cyanide in water using hydrophobic CdSe quantum dots 

    E-Print Network [OSTI]

    Dryden D.T.F.; Mareque-Rivas J.C.; Galve-Gasion J.A.; Stevenson E.I.; Touceda-Varela A.

    2008-05-01

    The ability of 2,2'-bipyridine-bound copper(II) ions to quench the photoluminescence of hydrophobic CdSe quantum dots is used to create a novel, selective turn-on fluorescence cyanide sensor.

  14. 35898 Viernes 11 octubre 2002 BOE nm. 244 6. Los premios se pagarn a la terminacin de

    E-Print Network [OSTI]

    Fitze, Patrick

    relativos a edificación, y, en lo que corresponda, a los demás tipos de construcciones, en tanto no se única. Plazo de adaptación nor- mativa. Los proyectos y construcciones de nuevas edifica- ciones y otras

  15. Molecular beam epitaxial growth and characterization of Bi{sub 2}Se{sub 3}/II-VI semiconductor heterostructures

    SciTech Connect (OSTI)

    Chen, Zhiyi Zhao, Lukas; Krusin-Elbaum, Lia; Garcia, Thor Axtmann; Tamargo, Maria C.; Hernandez-Mainet, Luis C.; Deng, Haiming

    2014-12-15

    Surfaces of three-dimensional topological insulators (TIs) have been proposed to host quantum phases at the interfaces with other types of materials, provided that the topological properties of interfacial regions remain unperturbed. Here, we report on the molecular beam epitaxy growth of II-VI semiconductor–TI heterostructures using c-plane sapphire substrates. Our studies demonstrate that Zn{sub 0.49}Cd{sub 0.51}Se and Zn{sub 0.23}Cd{sub 0.25}Mg{sub 0.52}Se layers have improved quality relative to ZnSe. The structures exhibit a large relative upward shift of the TI bulk quantum levels when the TI layers are very thin (?6nm), consistent with quantum confinement imposed by the wide bandgap II-VI layers. Our transport measurements show that the characteristic topological signatures of the Bi{sub 2}Se{sub 3} layers are preserved.

  16. 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.

    1989-01-01

    /mudstone microfacies (Thrash Field) 5) Argillaceous, spiculitic, crinoid ? bryozoan mudstone/ 32 wackestone micro facies (Quanah SE Field) 6) Dolomitic, spiculiferous, silt ? sized wackestone/mudstone microfacies (Quanah SE Field) 7) Dolomitic, cherty floatstone... crinoi. d-bryozoan mudstona/wackestone Dolomitic, spiculiferous silty wackestone/muc(ALone Well Well to morleratc Pine to medium (0. 007 mm to 0. 00 ~) silty to I'ine to 0. 00 mm) Dul row Discontinuous, p&. anar, thin, laminae Micro(null inn...

  17. 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

  18. 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

  19. Large single crystal quaternary alloys of IB-IIIA-Se/sub 2/ and methods of synthesizing the same

    DOE Patents [OSTI]

    Ciszek, T.F.

    1986-07-15

    New alloys of Cu/sub x/Ag/sub (1-x)/InSe/sub 2/ (where x ranges between 0 and 1 and preferably has a value of about 0.75) and CuIn/sub y/Ga/sub (1-y)/Se/sub 2/ (where y ranges between 0 and 1 and preferably has a value of about 0.90) in the form of single crystals with enhanced structure perfection, which crystals are substantially free of fissures, are disclosed. Processes are disclosed for preparing the new alloys of Cu/sub x/Ag/sub (1-x)/InSe/sub 2/. The process includes placing stoichiometric quantities of a Cu, Ag, In, and Se reaction mixture or stoichiometric quantities of a Cu, In, Ga, and Se reaction mixture in a refractory crucible in such a manner that the reaction mixture is surrounded by B/sub 2/O/sub 3/, placing the thus loaded crucible in a chamber under a high pressure atmosphere of inert gas to confine the volatile Se to the crucible, and heating the reaction mixture to its melting point. The melt can then be cooled slowly to form, by direct solidification, a single crystal with enhanced structure perfection, which crystal is substantially free of fissures.

  20. Large single crystal quaternary alloys of IB-IIIA-SE.sub.2 and methods of synthesizing the same

    DOE Patents [OSTI]

    Ciszek, Theodore F. (Evergreen, CO)

    1988-01-01

    New alloys of Cu.sub.x Ag.sub.(1-x) InSe.sub.2 (where x ranges between 0 and 1 and preferably has a value of about 0.75) and CuIn.sub.y Ga.sub.(1-y) Se.sub.2 (where y ranges between 0 and 1 and preferably has a value of about 0.90) in the form of single crystals with enhanced structure perfection, which crystals are substantially free of fissures are disclosed. Processes are disclosed for preparing the new alloys of Cu.sub.x Ag.sub.(1-x) InSe.sub.2. The process includes placing stoichiometric quantities of a Cu, Ag, In, and Se reaction mixture or stoichiometric quantities of a Cu, In, Ga, and Se reaction mixture in a refractory crucible in such a manner that the reaction mixture is surrounded by B.sub.2 O.sub.3, placing the thus loaded crucible in a chamber under a high pressure atmosphere of inert gas to confine the volatile Se to the crucible, and heating the reaction mixture to its melting point. The melt can then be cooled slowly to form, by direct solidification, a single crystal with enhanced structure perfection, which crystal is substantially free of fissures.

  1. 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.

    2012-06-01

    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.

  2. Structural, electrical and optical properties of Bi{sub 2}Se{sub 3} and Bi{sub 2}Se{sub (3-x)}Te {sub x} thin films

    SciTech Connect (OSTI)

    Augustine, Saji [Crystal Growth Laboratory, Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala, (India) and Materials and Process Simulation Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305701 (Korea, Republic of)]. E-mail: sajia@kaist.ac.kr; Ampili, S. [Crystal Growth Laboratory, Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Kang, Jeung Ku [Materials and Process Simulation Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305701 (Korea, Republic of); Mathai, Elizabeth [Crystal Growth Laboratory, Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India)

    2005-08-11

    Thin films of Bi{sub 2}Se{sub 3}, Bi{sub 2}Se{sub 2.9}Te{sub 0.1}, Bi{sub 2}Se{sub 2.7}Te{sub 0.3} and Bi{sub 2}Se{sub 2.6}Te{sub 0.4} are prepared by compound evaporation. Micro structural, optical and electrical measurements are carried out on these films. X-ray diffraction pattern indicates that the as-prepared films are polycrystalline in nature with exact matching of standard pattern. The composition and morphology are determined using energy dispersive X-ray analysis and scanning electron microscopy (SEM). The optical band gap, which is direct allowed, is 0.67 eV for Bi{sub 2}Se{sub 3} thin films and the activation energy is 53 meV. Tellurium doped thin films also show strong optical absorption corresponding to a band gap of 0.70-0.78 eV. Absolute value of electrical conductivity in the case of tellurium doped thin film shows a decreasing trend with respect to parent structure.

  3. 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. Coey, J. M. D.; Stamenov, P.; Alaria, J.

    2014-05-07

    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.

  4. 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)

    2015-01-01

    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.

  5. 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

    2015-01-20

    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

  6. Fabrication and characterization of Cu(In,Ga)Se{sub 2} p-channel thin film transistors

    SciTech Connect (OSTI)

    Zhu, Xiaobo [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Liu, C. W., E-mail: chee@cc.ee.ntu.edu.tw [Graduate Institute of Electronics Engineering, Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, and Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan and National Nano Device Labs, Hsinchu, Taiwan (China)

    2014-10-06

    Cu(In,Ga)Se{sub 2} thin film transistors are demonstrated with the on-off ratio of ?10{sup 3} and the saturation hole mobility of 1.8?cm{sup 2}/V-s. Due to the high hole concentration (?5?×?10{sup 17?}cm{sup ?3}), the channel needs to be etched to turn off for the accumulation mode operation. The Cu(In,Ga)Se{sub 2} film after etching reveals a larger mobility, and a narrower (112) X-ray diffraction line than the original thick layer, indicating the better crystallinity of the initial growth as compared to the subsequent Cu(In,Ga)Se{sub 2} layer. Both the hole concentration and the saturation mobility increase with the decreasing Cu/(In?+?Ga) ratio probably due to the effect of Cu vacancies.

  7. 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)

    2015-01-01

    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.

  8. Quasiparticle interference, quasiparticle interactions, and the origin of the charge density wave in 2H–NbSe2

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

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

    2015-01-21

    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?. Thus, 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 fermiologymore »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.« less

  9. Van der Waals Epitaxial Growth of Single-Crystal Two-Dimensional GaSe on Graphene

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

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V.; Puretzky, Alexander A.; Lin, Ming-Wei; Chi, Miaofang; Idrobo Tapia, Juan Carlos; et al

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigationsmore »of interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.« less

  10. Van der Waals epitaxial growth of two-dimensional single-crystalline GaSe domains on graphene

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

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V.; Puretzky, Alexander A.; Lin, Ming -Wei; Chi, Miaofang; Idrobo Tapia, Juan Carlos; et al

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigationsmore »of interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.« less

  11. 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.; Richard, P.; Xu, N.; Xu, Y. -M.; Ma, J.; Qian, T.; Fedorov, A. V.; Denlinger, J. D.; Gu, G. D.; Ding, H.

    2014-10-27

    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. 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.

    2011-08-01

    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.

  13. 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.

    2014-02-21

    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.

  14. 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

    with a controllable composition modulation can afford ordered p-n junctions and continuous charge carrier transport pathways without deadends, which is an advantage over the random p-n junctions. Therefore, NW solar cells10:3 confirming the chemical composition of In2Se3. High- resolution TEM (HRTEM) (Figure 1c) and selected

  15. DOI: 10.1002/adma.200701125 Light-Induced Charge Transfer in Pyrene/CdSe-SWNT Hybrids**

    E-Print Network [OSTI]

    Gruner, George

    DOI: 10.1002/adma.200701125 Light-Induced Charge Transfer in Pyrene/CdSe-SWNT Hybrids solar cells.[20­24] Holes are transported along the polymer chains and electrons hop along the nanopar to low hole mobility and hence limit- ing the solar cell efficiency. Semiconductor nanorod-polymer hybrid

  16. 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)

    2014-03-21

    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.

  17. Materials data requirements for high power target design E. Noah, 4th HPTW, Malm, SE, 2-6 May 2011

    E-Print Network [OSTI]

    McDonald, Kirk

    Materials data requirements for high power target design E. Noah, 4th HPTW, Malmö, SE, 2-6 May 2011 Materials Data Requirements For High Power Target Design E. Noah, C. Kharoua, F. Plewinski, P. Sabbagh ESS Target Division 4th HPTW May 2-6, 2011, Malmö #12;Materials data requirements for high power

  18. Measuring charge trap occupation and energy level in CdSe/ZnS quantum dots using a scanning tunneling microscope

    E-Print Network [OSTI]

    Hummon, M. R.

    We use a scanning tunneling microscope to probe single-electron charging phenomena in individual CdSe/ZnS (core/shell) quantum dots (QDs) at room temperature. The QDs are deposited on top of a bare Au thin film and form a ...

  19. OligoceneMiocene basin evolution in SE Anatolia, Turkey: constraints on the closure of the eastern Tethys gateway

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Oligocene­Miocene basin evolution in SE Anatolia, Turkey: constraints on the closure of the eastern, The Netherlands 3 Department of Geology, Firat University, Elazig, Turkey 4 Natural History Museum Vienna, Austria, we focus on the evolution of Oligocene and Miocene foreland basins in the southernmost part of Turkey

  20. 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

  1. 104 Royal Swedish Academy of Sciences 2001 Ambio Vol. 30 No. 2, March 2001 http://www.ambio.kva.se

    E-Print Network [OSTI]

    Thomas, Valerie

    ://www.ambio.kva.se ENVIRONMENTALISM AND ANTI-SOVIET POLITICS The environmental movement was central to the political trans- formation came to power, practically ensured that environmental issues would become a major focal point- session.... Green feelings now run as deep, and are as politically challenging, as anywhere in the world

  2. Spin glass and semiconducting behavior in one-dimensional BaFe2-dSe3 (d~2) crystals

    SciTech Connect (OSTI)

    Saparov, Bayrammurad I [ORNL; Calder, Stuart A [ORNL; Sipos, Balazs [ORNL; Cao, Huibo [ORNL; Chi, Songxue [ORNL; Singh, David J [ORNL; Christianson, Andrew D [ORNL; Lumsden, Mark D [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL)

    2011-01-01

    We investigate the physical properties and electronic structure of BaFe{sub 1.79(2)}Se{sub 3} crystals, which were grown out of tellurium flux. The crystal structure of the compound, an iron-deficient derivative of the ThCr{sub 2}Si{sub 2}-type, is built upon edge-shared FeSe{sub 4} tetrahedra fused into double chains. The semiconducting BaFe{sub 1.79(2)}Se{sub 3} ({rho}{sub 295K} = 0.18 {Omega} {center_dot} cm and E{sub g} = 0.30 eV) does not order magnetically; however, there is evidence for short-range magnetic correlations of spin glass type (T{sub f} {approx} 50 K) in magnetization, heat capacity, and neutron diffraction results. A one-third substitution of selenium with sulfur leads to a slightly higher electrical conductivity ({rho}{sub 295K } = 0.11 {Omega} {center_dot} cm and E{sub g} = 0.22 eV) and a lower spin glass freezing temperature (T{sub f} {approx} 15 K), corroborating with higher electrical conductivity reported for BaFe{sub 2}S{sub 3}. According to the electronic structure calculations, BaFe{sub 2}Se{sub 3} can be considered as a one-dimensional ladder structure with a weak interchain coupling.

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

    E-Print Network [OSTI]

    Anderson, Timothy J.

    2008-01-01

    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

  4. 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

  5. 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

  6. XIII JORNADAS DE PARALELISMO--LLEIDA, SEPTIEMBRE 2002 1 Resumen --Se realiza una breve introduccin a los

    E-Print Network [OSTI]

    Miguel-Alonso, José

    introducción a los algoritmos de estimación de distribuciones, dentro del ámbito de la computación evolutiva. Al aplicar estos algoritmos a un problema de concordancia inexacta de grafos, se observan largos observado de 4,53. Palabras clave -- Algoritmos de estimación de distribuciones (EDAs), computación

  7. Deformation of a pervasively molten middle crust: insights from the neoproterozoic Ribeira-Aracuai orogen (SE Brazil)

    E-Print Network [OSTI]

    Tommasi, Andrea

    -Arac¸uai´ orogen (SE Brazil) Alain Vauchez,1 Marcos Egydio-Silva,2 Marly Babinski,2 Andre´a Tommasi,1 Alexandre, 562 Cidade Universitaria, 05508-900 Sa~o Paulo, SP, Brazil; 3 Instituto de Geocie^ncias Universidade Federal de Minas Gerais, Av. Anto^nio Carlos, 6627 Pampulha, 31270-901 Belo Horizonte, MG, Brazil; 4

  8. 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

  9. Efficient band alignment for ZnxCd1xSe QD-sensitized TiO2 solar cells

    E-Print Network [OSTI]

    Cao, Guozhong

    dots (QDs), such as CdS,2,3 CdTe,4­6 PbS,7,8 PbSe,9,10 and InP,11,12 have recently been extensively in the enhancement of the power conversion efficiency and device stability. As an alternative, semiconductor quantum

  10. Photoluminescence Enhancement in CdSe/ZnS–DNA linked–Au Nanoparticle Heterodimers Probed by Single Molecule Spectroscopy

    SciTech Connect (OSTI)

    Cotlet, M.; Maye, M.M.; Gang, O.

    2010-07-26

    Photoluminescence enhancement of up to 20 fold is demonstrated at the single molecule level for heterodimers composed of a core/shell CdSe/ZnS semiconductive quantum dot and a gold nanoparticle of 60 nm size separated by a 32 nm-long dsDNA linker when employing optical excitation at wavelengths near the surface plasmon resonance of the gold nanoparticle.

  11. 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

  12. Journal of Crystal Growth 281 (2005) 209219 Effect of a CuSe secondary phase on the epitaxial

    E-Print Network [OSTI]

    Anderson, Timothy J.

    2005-01-01

    -cost thin-film solar cells. The advantages of this class of materials include their high that appears during epitaxial growth of CuInSe2 (CIS) films on (1 0 0) GaAs substrates was investigated. CIS films with different copper to indium molar ratios were deposited on (1 0 0) GaAs substrates at 360 1C

  13. Pgina Inicial Empresas Start-ups portuguesas mostram-se hoje a investidores suecos em Lisboa Empresas criadas em

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Energia Internacional O Governo quer cortar os salários também nas empresas públicas. Mas ao contrário do ano... LEIA TUDO Últimas Telecom Construção Energia Internacional | Empresas criadas em PortugalPágina Inicial Empresas Start-ups portuguesas mostram-se hoje a investidores suecos em Lisboa

  14. 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. The experimental evidence that grading improves device performance, however, has not been compelling, mostly

  15. Simulation of Polycrystalline Cu(In,Ga)Se2 Solar Cells in Two Dimensions Markus Gloeckler, Wyatt K. Metzger1

    E-Print Network [OSTI]

    Sites, James R.

    Simulation of Polycrystalline Cu(In,Ga)Se2 Solar Cells in Two Dimensions Markus Gloeckler, Wyatt K) solar cells and its effects on solar-cell performance. The simulations predict that (1) for device cells have nearly reached 20% [1]. It is often argued that these improvements have been achieved despite

  16. RVF The Swedish Association of Waste Management www.rvf.se of the Swedish report "Frbrnning av avfall en

    E-Print Network [OSTI]

    Columbia University

    RVF ­ The Swedish Association of Waste Management www.rvf.se 1 (19) Summary of the Swedish report knowledge in this area, the Swedish Association of Waste Management (RVF) has taken the initiative within the areas of waste management and recycling. The owners of Sweden's 22 waste incineration plants

  17. 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

  18. Information Technologies Activity Report MA Y SE P T E M B E R 2 0 14

    E-Print Network [OSTI]

    Firestone, Jeremy

    Information Technologies Activity Report MA Y ­ SE P T E M B E R 2 0 14 Farber HPC cluster now; · Registrar's Office; · Institutional Research; and 1 #12;Information Technologies Activity Report May available Building on the success of the Mills High-Performance Computing (HPC) cluster, UD Information

  19. 1. General description The NXP Semiconductors SE97 measures temperature from -40 C and +125 C and

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    the Temp Sensor (TS) on DIMM allows accurate monitoring of the DIMM module temperature to better estimate1. General description The NXP Semiconductors SE97 measures temperature from -40 °C and +125 °C on a Dual In-Line Memory Module (DIMM) measuring the DRAM temperature in accordance with the new JEDEC (JC

  20. Benefits of Carrier Pocket Anisotropy to Thermoelectric Performance: The case of p-type AgBiSe2

    SciTech Connect (OSTI)

    Parker, David S; May, Andrew F; Singh, David J

    2015-01-01

    We study theoretically the effects of anisotropy on the thermoelectric performance of p-type AgBiSe2. We present an apparent realization of the thermoelectric benefits of one-dimensional plate-like carrier pocket anisotropy in the valence band of this material. Based on first principles calculations we find a substantial anisotropy in the electronic structure, likely favorable for thermoelectric performance, in the valence bands of the hexagonal phase of the silver chalcogenide thermoelectric AgBiSe2, while the conduction bands are more isotropic, and in our experiments do not attain high performance. AgBiSe2 has already exhibited a ZT value of 1.5 in a high-temperature disordered fcc phase, but room-temperature performance has not been demonstrated. We develop a theory for the ability of anisotropy to decouple the density-of-states and conductivity effective masses, pointing out the influence of this effect in the high performance thermoelectrics Bi2Te3 and PbTe. From our first principles and Boltzmann transport calculations we find that p-type AgBiSe2 has substantial promise as a room temperature thermoelectric, and estimate its performance.

  1. Genetic signature of a recent invasion: The ragged sea hare Bursatella leachii in Mar Menor (SE Spain)

    E-Print Network [OSTI]

    Borges, Rita

    Genetic signature of a recent invasion: The ragged sea hare Bursatella leachii in Mar Menor (SE, Portugal b Departamento de Ciencias del Mar y Biología Aplicada, Universidad de Alicante, Campus de San hypothesis for the origin of invasions is that colonization by invasive species is most often associated

  2. 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

  3. 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

  4. 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)

    2014-02-28

    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.

  5. Comparative Study of the Defect Point Physics and Luminescence of the Kesterites Cu2ZnSnS4 and Cu2ZnSnSe4 and Chalcopyrite Cu(In,Ga)Se2: Preprint

    SciTech Connect (OSTI)

    Romero, M. J.; Repins, I.; Teeter, G.; Contreras, M.; Al-Jassim, M.; Noufi, R.

    2012-08-01

    In this contribution, we present a comparative study of the luminescence of the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) and their related chalcopyrite Cu(In,Ga)Se2 (CIGSe). Luminescence spectroscopy suggests that the electronic properties of Zn-rich, Cu-poor kesterites (both CZTS and CZTSe) and Cu-poor CIGSe are dictated by fluctuations of the electrostatic and chemical potentials. The large redshift in the luminescence of grain boundaries in CIGSe, associated with the formation of a neutral barrier is clearly observed in CZTSe, and, to some extent, in CZTS. Kesterites can therefore replicate the fundamental electronic properties of CIGSe.

  6. Magneto-optical characterizations of FeTe???Se??? thin films with critical current density over 1 MA/cm²

    SciTech Connect (OSTI)

    Sun, Yue; Li, Qiang; Tsuchiya, Yuji; Pyon, Sunseng; Tamegai, Tsuyoshi; Zhang, Cheng; Ozaki, Toshinori

    2015-01-01

    We performed magneto-optical (MO) measurements on FeTe???Se??? thin films grown on LaAlO? (LAO) and Yttria-stabilized zirconia (YSZ) single-crystalline substrates. These thin films show superconducting transition temperature Tc ~19 K, 4 K higher than the bulk sample. Typical roof-top patterns can be observed in the MO images of thin films grown on LAO and YSZ, from which a large and homogeneous critical current density Jc ~ 3 - 4 x 10? A/cm² at 5 K was obtained. Magnetic flux penetration measurement reveals that the current is almost isotropically distributed in the two thin films. Compared with bulk crystals, FeTe???Se??? thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive for applications.

  7. Properties of the 0{sub 2}{sup +} state and isospin excitation in the N=Z nucleus {sup 68}Se

    SciTech Connect (OSTI)

    Al-Khudair, Falih H.; Li, Y. S.; Long, G. L. [Key Laboratory for Quantum Information and Measurements and Department of Physics, Tsinghua University, Beijing 100084 (China); Center of Nuclear Theory, Lanzhou National Laboratory of Accelerators, Lanzhou 730000 (China)

    2007-05-15

    Band structure and electromagnetic transition properties of the low-lying states in the N=Z {sup 68}Se nucleus were studied within the framework of interacting boson model 3. The isospin excitation states with T>T{sub Z} are identified. The M1 and E2 matrix elements for low-lying states have been investigated and were used to identify the low-lying mixed symmetry states. Special attention is given to the occurrence of 0{sub 2}{sup +} state, recently predicted by the projected shell-model (PSM) calculation. The present predicted spectrum for {sup 68}Se is close to the recent PSM results and confirms the results for the 0{sub 2}{sup +} state. The calculated results are compared with available experimental data, and they are in general good agreement.

  8. SPECTROSCOPIC INVESTIGATION OF (NH4)2S TREATED GaSeTe FOR RADIATION DETECTOR APPLICATIONS

    SciTech Connect (OSTI)

    Nelson, A; Laurence, T; Conway, A; Behymer, E; Sturm, B; Voss, L; Nikolic, R; Payne, S; Mertiri, A; Pabst, G; Mandal, K; Burger, A

    2009-08-04

    The surface of the layered III-VI chalcogenide semiconductor GaSeTe was treated with (NH{sub 4}){sub 2}S at 60 C to modify the surface chemistry and determine the effect on transport properties. Room temperature photoluminescence (PL) measurements were used to assess the effect of the (NH{sub 4}){sub 2}S treatment on surface defect states. Evaluation of the subsequent surface chemistry was performed with high-resolution core-level photoemission measurements. Metal overlayers were deposited on the (NH{sub 4}){sub 2}S treated surfaces and the I-V characteristics were measured. The measurements were correlated to understand the effect of (NH{sub 4}){sub 2}S modification of the interfacial electronic structure with the goal of optimizing the metal/GaSeTe interface for radiation detector devices.

  9. Magneto-optical characterizations of FeTe???Se??? thin films with critical current density over 1 MA/cm²

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

    Sun, Yue; Li, Qiang; Tsuchiya, Yuji; Pyon, Sunseng; Tamegai, Tsuyoshi; Zhang, Cheng; Ozaki, Toshinori

    2014-12-03

    We performed magneto-optical (MO) measurements on FeTe???Se??? thin films grown on LaAlO? (LAO) and Yttria-stabilized zirconia (YSZ) single-crystalline substrates. These thin films show superconducting transition temperature Tc ~19 K, 4 K higher than the bulk sample. Typical roof-top patterns can be observed in the MO images of thin films grown on LAO and YSZ, from which a large and homogeneous critical current density Jc ~ 3 - 4 x 10? A/cm² at 5 K was obtained. In this study, magnetic flux penetration measurement reveals that the current is almost isotropically distributed in the two thin films. Compared with bulk crystals,more »FeTe???Se??? thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive for applications.« less

  10. All-metallic electrically gated 2H-TaSe{sub 2} thin-film switches and logic circuits

    SciTech Connect (OSTI)

    Renteria, J.; Jiang, C.; Yan, Z.; Samnakay, R.; Goli, P.; Pope, T. R.; Salguero, T. T.; Wickramaratne, D.; Lake, R. K.; Khitun, A. G.; Balandin, A. A.

    2014-01-21

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe{sub 2} were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe{sub 2}–Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

  11. 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.

    2006-05-01

    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.

  12. 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; et al

    2015-04-01

    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 more »ns. The ultranarrow resonance (« less

  13. Direct imaging of enhanced current collection on grain boundaries of Cu(In,Ga)Se{sub 2} solar cells

    SciTech Connect (OSTI)

    Kim, JunHo; Kim, SeongYeon; Jiang, Chun-Sheng; Ramanathan, Kannan; Al-Jassim, Mowafak M.

    2014-02-10

    We report on direct imaging of current collection by performing conductive atomic force microscopy (C-AFM) measurement on a complete Cu(In,Ga)Se{sub 2} solar cell. The localized current was imaged by milling away the top conductive layer of the device by repeated C-AFM scans. The result exhibits enhanced photocurrent collection on grain boundaries (GBs) of CIGS films, consistent with the argument for electric-field-assisted carrier collection on the GBs.

  14. First demonstration of CdSe as a photocatalyst for hydrogen evolution from water under UV and visible lightw

    E-Print Network [OSTI]

    Osterloh, Frank

    show catalytic activity for photochemical hydrogen evolution from aqueous Na2S/Na2SO3 solution under­10 but can produce H2 from aqueous solutions containing sacrificial electrons donors, such as Na2S and Na2SO3 evolu- tion from water can be achieved with CdSe nanoribbons in the presence of Na2S/Na2SO3

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

    SciTech Connect (OSTI)

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

    2014-06-14

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

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOE SafetyofDepartment. "National MidcourseEnergy DOE

  17. 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.

    2015-05-01

    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.

  18. 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; et al

    2015-05-28

    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. Intermediatemore »compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures.« less

  19. Photo-crystallization in a-Se layer structures: Effects of film-substrate interface-rigidity

    SciTech Connect (OSTI)

    Lindberg, G. P.; Gross, N.; Weinstein, B. A.; O'Loughlin, T.; Mishchenko, A.; Reznik, A.; Abbaszadeh, S.; Karim, K. S.; Belev, G.

    2014-11-21

    Amorphous selenium (a-Se) films deposited on rigid substrates can undergo photo-induced crystallization (PC) even at temperatures (T) well below the glass transition, T{sub g}???313?K. Substrate-generated shear strain is known to promote the PC process. In the present work, we explore the influence of different substrates (Si and glass), and different film-layer-substrate combinations, on the PC in a variety of a-Se films and film-structures. The intermediate layers (indium tin oxide and polyimide) are chosen to promote conductivity and/or to be a buffer against interface strain in structures of interest for digital imaging applications. The PC characteristics in these samples are evaluated and compared using optical microscopy, atomic-force microscopy, Raman mapping, and T-dependent Raman spectroscopy. Both the presence of a soft intermediate layer, and the thermal softening that occurs for T increasing through T{sub g}, inhibit the tendency for the onset of PC. The extensive PC mapping results in the wide range of samples studied here, as well as the suppression of PC near T{sub g} in this array of samples, strongly support the generality of this behavior. As a consequence, one may expect that the stability of a-Se films against PC can be enhanced by decreasing the rigidity of the film-substrate interface. In this regard, advanced film structures that employ flexible substrates, soft intermediate layers, and/or are designed to be operated near T{sub g} should be explored.

  20. A p ? n transition for Sn-doped Cu(In,Ga)Se{sub 2} bulk materials

    SciTech Connect (OSTI)

    Monsefi, Mehrdad; Kuo, Dong-Hau, E-mail: dhkuo@mail.ntust.edu.tw

    2013-08-15

    Cu(In,Ga)Se{sub 2} (CIGSe) pellets at different Sn contents were fabricated by reactive liquid-phase sintering at 600–700 °C with the help of sintering aids of Sb{sub 2}S{sub 3} and Te. Powder preparation was based upon the molecular formula of Cu{sub 0.9}[(In{sub 0.7?x}Sn{sub x}Ga{sub 0.3}){sub 0.9}Sb{sub 0.1}](S{sub 0.15}Te{sub 0.2}Se{sub 1.65}) or Sn-x-CIGSe. Morphology, structure, and electrical property of Sn-doped CIGSe bulks were investigated. The composition of Sn-doped CIGSe is purposely designed for studying the doping effect on the CIGSe performance. The unexpected increase in hole concentration of CIGSe due to the donor doping is rationalized. A controllable n-type semiconductor is deliberately achieved for Sn-0.15-CIGSe and important for making a p/n homojunction in CIGSe solar cells. - Graphical abstract: The controls in defect type and electrical properties of Cu(In,Ga)Se{sub 2} by doping Sn{sup 4+} on the In{sup 3+} site. Highlights: • n-type Sn-CIGSe with n{sub e} of 6.4×10{sup 16} cm{sup ?3} and ?{sub e} of 2.3 cm{sup 2}/V s was obtained. • This n-type Sn-CIGSe was obtained by material design and composition control. • The reported n-type CIGSe was obtained from the Zn/CIGSe and CdS/CIGSe bilayers. • Extrinsic donor doping was explored through the results of electrical properties. • A n/p homojunction with Sn-CIGSe and undoped one can be used for solar cell devices.

  1. Elastic Scattering Of {sup 6,7}Li+{sup 80}Se At Near And Above Barrier Energies

    SciTech Connect (OSTI)

    Fimiani, L.; Marti, G. V.; Capurro, O. A.; Barbara, E. de; Testoni, J. E.; Zalazar, L.; Arazi, A.; Cardona, M. A.; Carnelli, P.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Fernandez Niello, J. O.

    2010-08-04

    In this work we propose to study the elastic scattering of the weakly bound projectiles {sup 6,7}Li on an intermediate mass target {sup 80}Se. From the experimental results presented here, precise angular distributions at energies below, around and above the nominal Coulomb barriers of the systems were obtained. The final goal of our work is to determine the characteristic parameters of the optical potential and use them to address the question of whether the usual threshold anomaly or the breakup threshold anomaly are present or not in these systems.

  2. Enhanced excitonic photoconductivity due to built-in internal electric field in TlGaSe{sub 2} layered semiconductor

    SciTech Connect (OSTI)

    Seyidov, MirHasan Yu. Suleymanov, Rauf A.; ?ale, Yasin; Balaban, Ertan

    2014-12-07

    The strong enhancement, by several orders of magnitude, of the excitonic peak within the photoconductivity spectrum of TlGaSe{sub 2} semiconductor was observed. The samples were polarized in external dc electric field, which was applied prior to the measurements. Due to the accumulation of charges near the surface, an internal electric field was formed. Electron-hole pairs that were created after the absorption of light are fallen in and then separated by the built-in electric field, which prevents radiative recombination process.

  3. 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

    2009-08-13

    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.

  4. 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

    2011-01-01

    on the efficiency of CZTSSe solar cells and explain the high efficiency of the cells with high Se content. DOI: 10: Is there a similar limit to the efficiency as in Cu(In,Ga)Se2 cells, and why is the current highest-efficiency solar 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

  5. 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 ZnO sputtering on the performance of Cu(In,Ga)Se2 thin film solar cells Appl. Phys. Lett. 105, 083906

  6. 1.2 Variedades de curvas. O objetivo desta se,c"ao 'e em primeiro lugar o de especializar alguns resu*

    E-Print Network [OSTI]

    Tausk, Daniel Victor

    - eraliza,c"oes para espa,cos de se,c"oes de um fibrado geral, mas o objetivo des* *ta se,c"ao 'e jus N agora passa a ser chamad* *a de M. Teremos sempre um tipo M de espa,co de se,c"oes que fibrado misto sobre I (cu* *jo fibrado das bases 'e I x M). Teremos ent"ao dois tipos M1, M2 de espa

  7. 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

  8. 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

  9. 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

    â?? on ya se ha introducido en el lavado. vacio: Indica que el tambor estâ?? a vacâ?? �o de agua. lleno: Indica

  10. Density functional theory calculations of the turbostratically disordered compound [(SnSe)1+y]m(VSe2)n

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

    Rudin, Sven P.; Johnson, David C.

    2015-04-30

    Among composite materials that layer constituent substances of nanoscale thicknesses, [(SnSe)1+y ]m(VSe2)n emerges as an example where the constituents retain incommensurate lattice structures. Perpendicular to the stacking direction, the system exhibits random translations and random rotations on average, i.e., turbostratic disorder, with local regions showing twelvefold diffraction patterns. Earlier theoretical work on these structures showed that combining density functional theory with an empirical treatment of the van der Waals interaction gave structural parameters in good agreement with experiment, but no attempt was made to examine the relative orientations. Here we approximate the extended system with one extended constituent and onemore »finite constituent, which allows the treatment of all relative orientations on equal footing. Furthermore, the calculations show how the twelvefold periodicity follows from how the ions of the SnSe layer lock in with favored positions relative to the VSe2 layer, and the associated energy scale supports arguments for the overall turbostratic disorder.« less

  11. Polytypism, polymorphism, and superconductivity in TaSe2–xTex

    SciTech Connect (OSTI)

    Luo, Huixia; Xie, Weiwei; Tao, Jing; Inoue, Hiroyuki; Gyenis, András; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, Robert Joseph

    2015-03-03

    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 superconductivity 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. Thus, 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.

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

    SciTech Connect (OSTI)

    Wang, Congjun; Thompson, Robert L.; Baltrus, John; Matranga, Christopher

    2010-08-01

    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}.

  13. Shallow to deep transformation of Se donors in GaSb under hydrostatic pressure H. Navarro-Contreras, F. de Anda-Salazar, and J. Olvera-Hernandez

    E-Print Network [OSTI]

    McCluskey, Matthew

    Shallow to deep transformation of Se donors in GaSb under hydrostatic pressure H. Navarro, although it may be also an indication that the Se shallow donors change to deep donors associated pressures above a certain threshold value. The DX center is a deep-level defect found in many n

  14. [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

  15. 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

  16. 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

  17. Automi e Linguaggi Formali { A.A. 2013/2014 1. Dire se esiste un algoritmo (che termini in tempo nito) che, dato in

    E-Print Network [OSTI]

    Rossi, Francesca

    Automi e Linguaggi Formali { A.A. 2013/2014 Homework 7 22.11.2013 1. Dire se esiste un algoritmo ferma per la stringa ab 2. Dire se esiste un algoritmo (che termini in tempo #12;nito) che, dato

  18. Automi e Linguaggi Formali A.A. 2011/2012 1. Dire se esiste un algoritmo (che termini in tempo finito) che, dato in

    E-Print Network [OSTI]

    Rossi, Francesca

    Automi e Linguaggi Formali ­ A.A. 2011/2012 Homework 7 24.11.2011 1. Dire se esiste un algoritmo ferma per la stringa ab 2. Dire se esiste un algoritmo (che termini in tempo finito) che, dato in input

  19. 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-FILM INTRODUCTION Cu(InGa)Se2-based thin-film solar cells have high conversion-efficiencies (the laboratory record

  20. Enhanced Performance of CdS/CdSe Quantum Dot Cosensitized Solar Cells via Homogeneous Distribution of Quantum Dots in TiO2

    E-Print Network [OSTI]

    Cao, Guozhong

    , simply increasing film thickness did not make significant contribution to improving solar cell efficiencyEnhanced Performance of CdS/CdSe Quantum Dot Cosensitized Solar Cells via Homogeneous Distribution cosensitized solar cells. The CdS and CdSe quantum dots were prepared on TiO2 mesoporous film through

  1. 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

    inferred from features eroded on bedrock, New York metropolitan area, SE NY. If a glacier erodes bedrock Tryon Park, Central Park, and in the New York Botanical Garden. To Cite This Abstract: Sanders, J. E on bedrock, New York metropolitan area, SE NY (abs.): Geological Society of America, Abstracts with Programs

  2. Conflicting structural and geochronological data from the Ibituruna quartz-syenite (SE Brazil): Effect of protracted "hot" orogeny and slow cooling rate?

    E-Print Network [OSTI]

    Cattin, Rodolphe

    Conflicting structural and geochronological data from the Ibituruna quartz-syenite (SE Brazil-Pb and 40Ar-39Ar geochronology Slow cooling rate SE-Brazil neoproterozoic orogeny The Ibituruna quartz-rock. Unexpectedly, geochronological data suggest a rather different conclusion. LA-ICP-MS and SHRIMP ages of zircons

  3. 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)

    2014-05-14

    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.

  4. 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.

    2012-04-01

    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

  5. Temperature-dependent carrier–phonon coupling in topological insulator Bi{sub 2}Se{sub 3}

    SciTech Connect (OSTI)

    Lai, Yi-Ping; Liu, Jia-Ming; Chen, Hsueh-Ju; Wu, Kuang-Hsiung

    2014-12-08

    Temperature-dependent (11.0?K?294.5?K) carrier–phonon coupling in Bi{sub 2}Se{sub 3} is investigated by ultrafast pump?probe spectroscopy. The rise time of the differential reflectivity is interpreted by a combined effect of electron temperature relaxation and hot-phonon lifetime. The electron?phonon coupling constant of the bulk state (?=0.63±0.05) is deduced from theoretical fitting. Increasing hot-phonon lifetime with decreasing temperature is attributed to a decreasing phonon?phonon collision rate. A complete analysis of the thermalization process is presented. Understanding carrier and phonon dynamics is essential for future optoelectronic and spintronic applications of topological insulators.

  6. 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.

    2015-05-04

    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

  7. 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

    2008-10-22

    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.

  8. 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.

    2009-01-01

    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.

  9. 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)

    2009-02-15

    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.

  10. 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.

    2015-05-01

    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.

  11. UAMcifrasen Universidad Autnoma de Madrid

    E-Print Network [OSTI]

    Autonoma de Madrid, Universidad

    14 Estudios Italianos 3 8 11 Gerencia para el Desarrollo Sostenible (Se imparte en Guatemala) 25 17, Sociedad y Desarrollo en América Latina - - 36 Diploma de Formación Superior en Dirección Bancaria - - 38 Derecho y Administración Local 16 10 26 Desarrollo Económico Local (Se imparte en Argentina) 13 26 39

  12. Influence of defects on the charge density wave of ([SnSe]1+?)1(VSe2)1 ferecrystals

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

    Falmbigl, Matthias; Putzky, Daniel; Ditto, Jeffrey; Esters, Marco; Bauers, Sage R.; Ronning, Filip; Johnson, David C.

    2015-07-14

    A series of ferecrystalline compounds ([SnSe]1+?)1(VSe2)1 with varying Sn/V ratios were synthesized using the modulated elemental reactant technique. Temperature-dependent specific heat data reveal a phase transition at 102 K, where the heat capacity changes abruptly. An abrupt increase in electrical resistivity occurs at the same temperature, correlated with an abrupt increase in the Hall coefficient. Combined with the magnitude and nature of the specific heat discontinuity, this suggests that the transition is similar to the charge density wave transitions in transition metal dichalcogenides. An ordered intergrowth was formed over a surprisingly wide compositional range of Sn/V ratios of 0.89 ?more »1 + ? ? 1.37. X-ray diffraction and transmission electron microscopy reveal the formation of various volume defects in the compounds in response to the nonstoichiometry. The electrical resistivity and Hall coefficient data of samples with different Sn/V ratios show systematic variation in the carrier concentration with the Sn/V ratio. There is no significant change in the onset temperature of the charge density wave transition, only a variation in the carrier densities before and after the transition. Given the sensitivity of the charge density wave transitions of transition metal dichalcogenides to variations in composition, it is very surprising that the charge density wave transition observed at 102 K for ([SnSe]1.15)1(VSe2)1 is barely influenced by the nonstoichiometry and structural defects. As a result, this might be a consequence of the two-dimensional nature of the structurally independent VSe2 layers.« less

  13. “José del Valle: a Benthamite in Central America”

    E-Print Network [OSTI]

    Gómez, Alejandro

    2008-01-01

    Francisco Marroquín. Guatemala, 1993. Manuel ChavarríaPublicación Especial Nº 27. Guatemala. 1983, Rafael LeivaJosé de Pineda Ibarra, Guatemala, 1961. José Manuel de Arce

  14. Novelas de la diáspora centroamericana y la colonialidad del poder: Hacia una aproximación de-colonial al estudio de las literaturas centroamericanas

    E-Print Network [OSTI]

    Siu, Oriel Maria

    2012-01-01

    La metamorfosis del racismo en Guatemala: Uk’exwachixiik rina’ooj pa iximuleew. Guatemala: Cholsamaj, 2002. Print.Vámonos patria a caminar. Guatemala: Editorial Landívar,

  15. Innovation Beyond Individualism

    E-Print Network [OSTI]

    Nagata, Jason M

    2009-01-01

    western highlands of Guatemala, conducting and publishingresearch through the Guatemala Health Initiative. In westernremote communities in Guatemala and Kenya to laboratories in

  16. Methods to Study Intervention Sustainability Using Pre-existing, Community Interventions: Examples from the Water, Sanitation and Hygiene Sector

    E-Print Network [OSTI]

    Arnold, Benjamin Ford

    2009-01-01

    household handwashing intervention in rural Guatemala 3.1survey of diarrhoea in Guatemala: determining the optimalintervention in rural Guatemala. Int J Epidemiol. 2009;p.

  17. Keeping the Doctor Away: Experimental Evidence on Investment in Preventative Health Products

    E-Print Network [OSTI]

    Meredith, Jennifer; Robinson, Jonathan; Walker, Sarah; Wydick, Bruce

    2012-01-01

    a field experiment in Guatemala. ” Environment, Developmentin three smaller studies in Guatemala, India, and Uganda inthree smaller studies in Guatemala, India, Uganda, conducted

  18. The social implications of ritual behavior in the Maya Lowlands : a perspective from Minanha, Belize

    E-Print Network [OSTI]

    Schwake, Sonja Andrea

    2008-01-01

    del Atlas Arqueologico de Guatemala (PNTC- 001/103). InNo. 10, Atlas Arqueológico de Guatemala. Dillehay, T. 1995Nature. Vista Publications, Guatemala City. Joyce, Rosemary

  19. PRECISE CHARACTERIZATION OF GUATEMALAN OBSIDIAN SOURCES, AND SOURCE DETERMINATION OF ARTIFACTS FROM QUIRIGUA

    E-Print Network [OSTI]

    Stross, Fred H.

    2013-01-01

    precision sources in Guatemala. chemical characterization ofField Archaeology 5(1): Guatemala. Journal of Sheets, P.D.some obsidian flakes from Guatemala. American Antiquity 42:

  20. Does Agricultural Liberalization Reduce Rural Welfare in Less Developed Countries? The Case of CAFTA

    E-Print Network [OSTI]

    Taylor, J. Edward; Yunez Naude, Antonio; Jesurun-Clements, Nancy

    2007-01-01

    in El Salvador, Honduras, Guatemala y Nicaragua or financialgroups in El Salvador, Guatemala, Honduras and Nicaragua.countries: El Salvador, Guatemala, Honduras, and Nicaragua (

  1. Ideologies of language and gesture among Q'eqchi'-Maya mainstream and charismatic Catholics

    E-Print Network [OSTI]

    Hoenes del Pinal, Eric

    2008-01-01

    Gerardi Conedera, 1922-1998. Guatemala: Oficina de DerechosHumanos del Arzobispado de Guatemala.demandas (1986-1992). Guatemala: Facultad Latinoamericana de

  2. Migration and Health: Latinos in the United States

    E-Print Network [OSTI]

    Wallace, Steven P.; Castaneda, Xotichl

    2008-01-01

    part in ISA, activities: Guatemala, El Salvador, Honduras,2007 Notes: */ Includes: Guatemala, El Salvador, Honduras,or Mexican). 3/ Includes: Guatemala, El Salvador, Honduras,

  3. What Difference Does it Make? The Impact of Women in Politics in Costa Rica and New Zealand

    E-Print Network [OSTI]

    Caldwell, Christina

    2010-01-01

    page=35&year=2005. Guatemala. In World Encyclopedia ofFile (Infobase Publishing). Guatemala. 2009. 2009 [cited Mayargument is that women in Guatemala will have a much harder

  4. Race and Ethnicity and Latin America's United Nations Millennium Development Goals

    E-Print Network [OSTI]

    Telles, Edward E.

    2007-01-01

    to be achieved for Guatemala. While there may be littlein Mexico, Bolivia and Guatemala were slower than for non-ethnic ‘minority’ in Mexico, Guatemala, Bolivia while blacks

  5. My Heart Was Over There with you and I Was Here: Exploring the Immigration Narratives of Families Separated During the Course of Migration

    E-Print Network [OSTI]

    Lopez, Monica Elizabeth

    2010-01-01

    and child rearing in Guatemala. Latin American Perspectivesthat he would not leave Guatemala without her. So, when hisof humble beginnings. In Guatemala, her father worked as a

  6. Colonial K'iche' in Comparison with Yucatec Maya: Language, Adaptation, and Intercultural Contact

    E-Print Network [OSTI]

    Jones, Owen H.

    2009-01-01

    Sáenz de Santa María. Guatemala: Academia de Geografíae Historia de Guatemala, Publicación especial No. 30, 1985.of the Colonial Maya of Guatemala. Lampeter, Cerdignion,

  7. A tale of two roads: Land tenure, poverty, and politics on the Guatemalan frontier

    E-Print Network [OSTI]

    Carr, D

    2006-01-01

    Lacando´n. Santa Elena, Guatemala, Presiden- 747 cia de lade Desarr- 753 ollo Sostenible en Pete´n. Guatemala,Guatemala, Facultad Lati- 754 noamericana de Ciencias

  8. Characterization of few-layer 1T-MoSe{sub 2} and its superior performance in the visible-light induced hydrogen evolution reaction

    SciTech Connect (OSTI)

    Gupta, Uttam; Naidu, B. S.; Maitra, Urmimala; Rao, C. N. R.; Singh, Anjali; Shirodkar, Sharmila N.; Waghmare, Umesh V.

    2014-09-01

    Based on earlier results on the photocatalytic properties of MoS{sub 2}, the 1T form of MoSe{sub 2}, prepared by lithium intercalation and exfoliation of bulk MoSe{sub 2}, has been employed for the visible-light induced generation of hydrogen. 1T-MoSe{sub 2} is found to be superior to both 2H and 1T MoS{sub 2} as well as 2H-MoSe{sub 2} in producing hydrogen from water, the yield being in the 60–75 mmol?h{sup ?1}?g{sup ?1} range with a turn over frequency of 15–19 h{sup ?1}. First principles calculations reveal that 1T-MoSe{sub 2} has a lower work function than 2H-MoSe{sub 2} as well as 1T and 2H-MoS{sub 2}, making it easier to transfer an electron from 1T-MoSe{sub 2} for the production of H{sub 2}.

  9. Effect of argon gas flow rate on properties of film electrodes prepared by thermal vacuum evaporation from synthesized Cu{sub 2}SnSe{sub 3} source

    SciTech Connect (OSTI)

    Sabli, Nordin; Talib, Zainal Abidin; Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang (Malaysia); Zainal, Zulkarnain [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang (Malaysia); Hilal, Hikmat S. [SSERL, Department of Chemistry An-Najah N. University, PO Box 7, Nablus, West Bank (Country Unknown); Fujii, Masatoshi [Department of Molecular Science, School of Medicine, Shimane University, Izumo, Shimane, 693-8501 (Japan)

    2014-03-05

    This work describes a new technique to enhance photoresponse of metal chalcogenide-based semiconductor film electrodes deposited by thermal vacuum evaporation under argon gas flow from synthesized Cu{sub 2}SnSe{sub 3} sources. SnSe formation with Cu-doped was obtained under higher argon gas flow rate (V{sub A} = 25 cm{sup 3}/min). Higher value of photoresponse was observed for films deposited under V{sub A} = 25 cm{sup 3}/min which was 9.1%. This finding indicates that Cu atoms inside the SnSe film were important to increase carrier concentrations that promote higher photoresponse.

  10. 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.; Howe, R. C. T.; Runcorn, T. H.; Hu, G.; Torrisi, F.; Kelleher, E. J. R.; Hasan, T.

    2015-06-23

    nm) gap for monolayer MoSe2 [30, 35]. The nonlinear optical properties of few-layer MoSe2 have been studied by Wang et al. for UALPE MoSe2 dispersed in cyclo- hexylpyrrolidone (CHP) [11], and by Dong et al. in N-methyl-pyrrolidone (NMP) [36]; both... than considering only the surface energies or Hildebrand solubility pa- rameters of the solvents and materials [40, 41]. Experimental evidence suggests that NMP and CHP are two of the more suitable solvents for TMDs [41]. However, it is challenging...

  11. Electron-beam induced variation of surface profile in amorphous As{sub 20}Se{sub 80} films

    SciTech Connect (OSTI)

    Kaganovskii, Yu. E-mail: trunov.m@gmail.com; Trunov, M. L. E-mail: trunov.m@gmail.com; Cserhati, C.; Beke, D. L.; Kökényesi, S.

    2014-05-14

    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.

  12. CdSe/ZnS quantum dots based electrochemical immunoassay for the detection of phosphorylated bovine serum albumin

    SciTech Connect (OSTI)

    Pinwattana, Kulwadee; Wang, Jun; Lin, Chiann Tso; Wu, Hong; Du, Dan; Lin, Yuehe; Chailapakul, Orawon

    2010-11-15

    A CdSe/ZnS quantum dot (QD) based electrochemical immunoassay of phosphorylated bovine serum albumin as a protein biomarker is presented. The QDs were used as labels and were conjugated with the secondary anti-phosphoserine antibody in a heterogeneous sandwich immunoassay. First, the primary BSA antibody was immobilized on polystyrene microwells, followed by the addition of BSA-OP. After that, the QD-labeled anti-phosphoserine antibody was added into microwells for immunorecognition. Finally, the bound QD was dissolved in an acid-dissolution step and was detected by electrochemical stripping analysis. The measured current responses were proportional to the concentration of BSA-OP. Under optimal conditions, the voltammetric response was linear over the range of 0.5 - 500 ng mL-1 of BSA-OP, with a detection limit of 0.5 ng mL-1 at a deposition potential of -1.2 V for 120 s. It also shows good reproducibility with a relative standard deviation of 8.6% of six times determination of 25 ng mL-1 of BSA-OP. This QD-based electrochemical immunoassay offers great promise for simple and cost-effective analysis of protein biomarkers.

  13. Temperature-driven band inversion in Pb0.77Sn0.23Se: Optical and Hall effect studies

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

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

    2014-12-23

    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. Thus, density function theory calculation for the electronic band structure also make similar predictions.« less

  14. Emergence of coherence in the charge-density wave state of 2H-NbSe2

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

    Chatterjee, U.; Zhao, J.; Iavarone, M.; Di Capua, R.; Castellan, J. P.; Karapetrov, G.; Malliakas, C. D.; Kanatzidis, M. G.; Claus, H.; Ruff, J. P. C.; et al

    2015-02-17

    A charge-density wave (CDW) state has a broken symmetry described by a complex order parameter with an amplitude and a phase. The conventional view, based on clean, weak-coupling systems, is that a finite amplitude and long-range phase coherence set in simultaneously at the CDW transition temperature Tcdw. Here we investigate, using photoemission, X-ray scattering and scanning tunnelling microscopy, the canonical CDW compound 2H-NbSe2 intercalated with Mn and Co, and show that the conventional view is untenable. We find that, either at high temperature or at large intercalation, CDW order becomes short-ranged with a well-defined amplitude, which has impacts on themore »electronic dispersion, giving rise to an energy gap. The phase transition at Tcdw marks the onset of long-range order with global phase coherence, leading to sharp electronic excitations. Our observations emphasize the importance of phase fluctuations in strongly coupled CDW systems and provide insights into the significance of phase incoherence in ‘pseudogap’ states.« less

  15. 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)

    2009-10-19

    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.

  16. Uso de Desinfectantes en Programas de Limpieza Verde Los desinfectantes y sanitizantes se usan en la mayora de programas de limpieza. Los desinfectantes

    E-Print Network [OSTI]

    Oliver, Douglas L.

    ser enjuagados con agua. Lo mismo sucede cuando te lavas las manos con jabón y agua o cuando lavas instrucciones en la etiqueta. Si usas un concentrado, asegúrate que se mezcle el químico con la cantidad de agua

  17. Photo-Activated Luminescence of CdSe Quantum Dot Monolayers S. R. Cordero, P. J. Carson, R. A. Estabrook, G. F. Strouse, and S. K. Buratto*

    E-Print Network [OSTI]

    Photo-Activated Luminescence of CdSe Quantum Dot Monolayers S. R. Cordero, P. J. Carson, R. A passivation is even more critical in quantum dot solids where inter-dot coupling reduces the QY of the film

  18. 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.; et al

    2013-06-06

    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, whichmore »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.« less

  19. Limitation of the Open-Circuit Voltage Due to Metastable Intrinsic Defects in Cu(In,Ga)Se2 and Strategies to Avoid These Defects: Preprint

    SciTech Connect (OSTI)

    Lany, S.; Zunger, A.

    2008-05-01

    This paper summarizes using first-principles defect theory to investigate the role of intrinsic point defects in the limitation of the open-circuit voltage (VOC) in Cu(In,Ga)Se2 solar cells.

  20. 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.

    ZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY 1 M.A. Contreras, 2 T. Nakada, 2 M analysis between this type of solar cell and the slightly more efficient ZnO/CdS/Cu(In,Ga)Se2/Mo solar cell for conversion efficiency above 20% in thin-film polycrystalline solar cells. It quantifies the gains in current