Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges
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/10.1590/1980-5373-MR-2016-0675 http://hdl.handle.net/11449/170128 |
Resumo: | Titanium dioxide (TiO2) in the form of pellets (pressed powder) and thin films are investigated, revealing the presence of distinct phases: mainly anatase and rutile. Characterization of optical, structural and electrical properties were carried out on samples submitted to different sort of thermal annealing (TA), at distinct temperatures, 500 and 1000°C, due to their influence on the obtained phases. TA temperature along with pressure application for sample conformation, determine the bands present in the photoluminescence (PL) spectra, being about 550nm, characteristic of anatase phase and 800nm, related to the presence of rutile phase. The bandgap of thin films is determined from optical absorbance data, yielding 3.4eV for anatase phase (indirect transition), and 2.9eV for rutile phase (direct transition). Besides, irradiation with monochromatic light strongly affects the thin film conductivity, but the energy range (above or below the bandgap energy) does not seem to affect the behavior, which is associated with the excitation of intrabandgap states or crystallites belonging to phases with distinct bandgaps. |
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Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy rangesConductivity decayPhase transitionPhotoluminescenceTitanium dioxideTitanium dioxide (TiO2) in the form of pellets (pressed powder) and thin films are investigated, revealing the presence of distinct phases: mainly anatase and rutile. Characterization of optical, structural and electrical properties were carried out on samples submitted to different sort of thermal annealing (TA), at distinct temperatures, 500 and 1000°C, due to their influence on the obtained phases. TA temperature along with pressure application for sample conformation, determine the bands present in the photoluminescence (PL) spectra, being about 550nm, characteristic of anatase phase and 800nm, related to the presence of rutile phase. The bandgap of thin films is determined from optical absorbance data, yielding 3.4eV for anatase phase (indirect transition), and 2.9eV for rutile phase (direct transition). Besides, irradiation with monochromatic light strongly affects the thin film conductivity, but the energy range (above or below the bandgap energy) does not seem to affect the behavior, which is associated with the excitation of intrabandgap states or crystallites belonging to phases with distinct bandgaps.Physics Department and POSMAT São Paulo State University - UNESPInstitute of Physics of São Carlos University of São Paulo - USPPhysics Department and POSMAT São Paulo State University - UNESPUniversidade Estadual Paulista (Unesp)Universidade de São Paulo (USP)De Aguiar Ramos, Roberto [UNESP]Boratto, Miguel Henrique [UNESP]Li, Maximo SiuDe Andrade Scalvi, Luis Vicente [UNESP]2018-12-11T16:49:23Z2018-12-11T16:49:23Z2017-07-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article866-873application/pdfhttp://dx.doi.org/10.1590/1980-5373-MR-2016-0675Materials Research, v. 20, n. 4, p. 866-873, 2017.1516-1439http://hdl.handle.net/11449/17012810.1590/1980-5373-MR-2016-0675S1516-143920170004008662-s2.0-85029494582S1516-14392017000400866.pdfScopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengMaterials Research0,398info:eu-repo/semantics/openAccess2023-12-17T06:16:09Zoai:repositorio.unesp.br:11449/170128Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462023-12-17T06:16:09Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
title |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
spellingShingle |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges De Aguiar Ramos, Roberto [UNESP] Conductivity decay Phase transition Photoluminescence Titanium dioxide |
title_short |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
title_full |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
title_fullStr |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
title_full_unstemmed |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
title_sort |
Emission properties related to distinct phases of sol-gel dip-coating titanium dioxide, and carrier photo-excitation in different energy ranges |
author |
De Aguiar Ramos, Roberto [UNESP] |
author_facet |
De Aguiar Ramos, Roberto [UNESP] Boratto, Miguel Henrique [UNESP] Li, Maximo Siu De Andrade Scalvi, Luis Vicente [UNESP] |
author_role |
author |
author2 |
Boratto, Miguel Henrique [UNESP] Li, Maximo Siu De Andrade Scalvi, Luis Vicente [UNESP] |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) Universidade de São Paulo (USP) |
dc.contributor.author.fl_str_mv |
De Aguiar Ramos, Roberto [UNESP] Boratto, Miguel Henrique [UNESP] Li, Maximo Siu De Andrade Scalvi, Luis Vicente [UNESP] |
dc.subject.por.fl_str_mv |
Conductivity decay Phase transition Photoluminescence Titanium dioxide |
topic |
Conductivity decay Phase transition Photoluminescence Titanium dioxide |
description |
Titanium dioxide (TiO2) in the form of pellets (pressed powder) and thin films are investigated, revealing the presence of distinct phases: mainly anatase and rutile. Characterization of optical, structural and electrical properties were carried out on samples submitted to different sort of thermal annealing (TA), at distinct temperatures, 500 and 1000°C, due to their influence on the obtained phases. TA temperature along with pressure application for sample conformation, determine the bands present in the photoluminescence (PL) spectra, being about 550nm, characteristic of anatase phase and 800nm, related to the presence of rutile phase. The bandgap of thin films is determined from optical absorbance data, yielding 3.4eV for anatase phase (indirect transition), and 2.9eV for rutile phase (direct transition). Besides, irradiation with monochromatic light strongly affects the thin film conductivity, but the energy range (above or below the bandgap energy) does not seem to affect the behavior, which is associated with the excitation of intrabandgap states or crystallites belonging to phases with distinct bandgaps. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-07-01 2018-12-11T16:49:23Z 2018-12-11T16:49:23Z |
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/10.1590/1980-5373-MR-2016-0675 Materials Research, v. 20, n. 4, p. 866-873, 2017. 1516-1439 http://hdl.handle.net/11449/170128 10.1590/1980-5373-MR-2016-0675 S1516-14392017000400866 2-s2.0-85029494582 S1516-14392017000400866.pdf |
url |
http://dx.doi.org/10.1590/1980-5373-MR-2016-0675 http://hdl.handle.net/11449/170128 |
identifier_str_mv |
Materials Research, v. 20, n. 4, p. 866-873, 2017. 1516-1439 10.1590/1980-5373-MR-2016-0675 S1516-14392017000400866 2-s2.0-85029494582 S1516-14392017000400866.pdf |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Materials Research 0,398 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
866-873 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_ |
1799965311971098624 |