Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1007/s10854-016-6202-x http://hdl.handle.net/11449/169237 |
Resumo: | Electrical and optical properties of heterojunction composed of GaAs and SnO2 are presented. SnO2 thin film was deposited by sol-gel-dip-coating and doped with Ce3+ whereas the GaAs layer was deposited by resistive evaporation or sputtering. The purpose of this investigation is to combine the blue emission properties of the rare-earth with the unique transport properties generated by the heterojunction assembly. We have found that illumination with light of energy above the GaAs bandgap and below the SnO2 bandgap decrease drastically the GaAs/SnO2 heterojunction resistance. Under this condition, the sample exhibits an unusual behavior: the conductivity is practically temperature independent. This behavior was related with the presence of interface conduction, which could be associated to a two-dimensional electron gas at the GaAs/SnO2 interface. This feature takes places only for the sample where the GaAs bottom layer is deposited by sputtering, which presents a smoother surface as inferred by AFM images. The deposition sequence of the layers is fundamental to provide sample excitation which strongly contributes to the sample conductivity. Energies above the SnO2 bandgap only excite the top oxide layer. When the GaAs is the top layer it acts as a shield, and only effects from the ions located close to the interface SnO2/GaAs are observed. Luminescence from the Ce3+ ion can be detected, but overlap with emission from the matrix. Results suggest that a more organized GaAs bottom layer may contribute for a more efficient emission and also for signal separation. |
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Repositório Institucional da UNESP |
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Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2Electrical and optical properties of heterojunction composed of GaAs and SnO2 are presented. SnO2 thin film was deposited by sol-gel-dip-coating and doped with Ce3+ whereas the GaAs layer was deposited by resistive evaporation or sputtering. The purpose of this investigation is to combine the blue emission properties of the rare-earth with the unique transport properties generated by the heterojunction assembly. We have found that illumination with light of energy above the GaAs bandgap and below the SnO2 bandgap decrease drastically the GaAs/SnO2 heterojunction resistance. Under this condition, the sample exhibits an unusual behavior: the conductivity is practically temperature independent. This behavior was related with the presence of interface conduction, which could be associated to a two-dimensional electron gas at the GaAs/SnO2 interface. This feature takes places only for the sample where the GaAs bottom layer is deposited by sputtering, which presents a smoother surface as inferred by AFM images. The deposition sequence of the layers is fundamental to provide sample excitation which strongly contributes to the sample conductivity. Energies above the SnO2 bandgap only excite the top oxide layer. When the GaAs is the top layer it acts as a shield, and only effects from the ions located close to the interface SnO2/GaAs are observed. Luminescence from the Ce3+ ion can be detected, but overlap with emission from the matrix. Results suggest that a more organized GaAs bottom layer may contribute for a more efficient emission and also for signal separation.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Graduate Program in Materials Science and Technology Department of Physics FC and POSMAT UNESP São Paulo State UniversityGraduate Program in Materials Science and Technology Department of Physics FC and POSMAT UNESP São Paulo State UniversityCNPq: 471359/2013-0Universidade Estadual Paulista (Unesp)Machado, Diego H. O. [UNESP]Scalvi, Luis V. A. [UNESP]Tabata, Américo [UNESP]da Silva, José H. D. [UNESP]2018-12-11T16:45:02Z2018-12-11T16:45:02Z2017-04-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article5415-5424application/pdfhttp://dx.doi.org/10.1007/s10854-016-6202-xJournal of Materials Science: Materials in Electronics, v. 28, n. 7, p. 5415-5424, 2017.1573-482X0957-4522http://hdl.handle.net/11449/16923710.1007/s10854-016-6202-x2-s2.0-850063417552-s2.0-85006341755.pdfScopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal of Materials Science: Materials in Electronics0,503info:eu-repo/semantics/openAccess2023-11-27T06:13:02Zoai:repositorio.unesp.br:11449/169237Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T18:50:47.757396Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
title |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
spellingShingle |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 Machado, Diego H. O. [UNESP] |
title_short |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
title_full |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
title_fullStr |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
title_full_unstemmed |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
title_sort |
Interface conduction and photo-induced electrical transport in the heterojunction formed by GaAs and Ce3+-doped SnO2 |
author |
Machado, Diego H. O. [UNESP] |
author_facet |
Machado, Diego H. O. [UNESP] Scalvi, Luis V. A. [UNESP] Tabata, Américo [UNESP] da Silva, José H. D. [UNESP] |
author_role |
author |
author2 |
Scalvi, Luis V. A. [UNESP] Tabata, Américo [UNESP] da Silva, José H. D. [UNESP] |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Machado, Diego H. O. [UNESP] Scalvi, Luis V. A. [UNESP] Tabata, Américo [UNESP] da Silva, José H. D. [UNESP] |
description |
Electrical and optical properties of heterojunction composed of GaAs and SnO2 are presented. SnO2 thin film was deposited by sol-gel-dip-coating and doped with Ce3+ whereas the GaAs layer was deposited by resistive evaporation or sputtering. The purpose of this investigation is to combine the blue emission properties of the rare-earth with the unique transport properties generated by the heterojunction assembly. We have found that illumination with light of energy above the GaAs bandgap and below the SnO2 bandgap decrease drastically the GaAs/SnO2 heterojunction resistance. Under this condition, the sample exhibits an unusual behavior: the conductivity is practically temperature independent. This behavior was related with the presence of interface conduction, which could be associated to a two-dimensional electron gas at the GaAs/SnO2 interface. This feature takes places only for the sample where the GaAs bottom layer is deposited by sputtering, which presents a smoother surface as inferred by AFM images. The deposition sequence of the layers is fundamental to provide sample excitation which strongly contributes to the sample conductivity. Energies above the SnO2 bandgap only excite the top oxide layer. When the GaAs is the top layer it acts as a shield, and only effects from the ions located close to the interface SnO2/GaAs are observed. Luminescence from the Ce3+ ion can be detected, but overlap with emission from the matrix. Results suggest that a more organized GaAs bottom layer may contribute for a more efficient emission and also for signal separation. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-04-01 2018-12-11T16:45:02Z 2018-12-11T16:45:02Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1007/s10854-016-6202-x Journal of Materials Science: Materials in Electronics, v. 28, n. 7, p. 5415-5424, 2017. 1573-482X 0957-4522 http://hdl.handle.net/11449/169237 10.1007/s10854-016-6202-x 2-s2.0-85006341755 2-s2.0-85006341755.pdf |
url |
http://dx.doi.org/10.1007/s10854-016-6202-x http://hdl.handle.net/11449/169237 |
identifier_str_mv |
Journal of Materials Science: Materials in Electronics, v. 28, n. 7, p. 5415-5424, 2017. 1573-482X 0957-4522 10.1007/s10854-016-6202-x 2-s2.0-85006341755 2-s2.0-85006341755.pdf |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Journal of Materials Science: Materials in Electronics 0,503 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
5415-5424 application/pdf |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128990147248128 |