Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1007/s11664-020-08416-z http://hdl.handle.net/11449/199296 |
Resumo: | A method to prepare Yb-doped TiO2 is proposed, using titanium isopropoxide and ytterbium oxide. Thin films and powders are produced through the sol–gel technique where the Yb concentrations are 0.01 at.%, 0.02 at.%, 1 at.%, 2 at.% 4 at.% and 8 at.%. The increase in the doping concentration intensifies gradually the sample transparency for the whole observed spectrum and reaches the transparency degree of the undoped sample with the highest concentration of ytterbium. By means of x-ray diffraction (XRD) we find that the solution’s pH leads to the formation of a rutile structure which is compensated for by lanthanide doping, inhibiting the anatase–rutile phase transformation. Then, the XRD profile depends on the Yb concentration, being mostly anatase for undoped and highly (8 at.%) doped samples, with mixed ratios of these two phases in other concentrations. Maintaining an acid solution leads to fewer intergrain defects in the rutile structure contributing to higher conductivity. Photo-induced investigation of 8 at.% Yb-doped thin film, using several light sources leads to distinct behavior concerning the excitation of intra-bandgap states and/or electron–hole pairs. This result helps to understand the electronic transport in Yb-doped TiO2 and shows that devices based on its conductivity may have improved performance by irradiation with controlled light energy. |
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Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Methodphase transitionphotoconductivityTitanium dioxideytterbiumA method to prepare Yb-doped TiO2 is proposed, using titanium isopropoxide and ytterbium oxide. Thin films and powders are produced through the sol–gel technique where the Yb concentrations are 0.01 at.%, 0.02 at.%, 1 at.%, 2 at.% 4 at.% and 8 at.%. The increase in the doping concentration intensifies gradually the sample transparency for the whole observed spectrum and reaches the transparency degree of the undoped sample with the highest concentration of ytterbium. By means of x-ray diffraction (XRD) we find that the solution’s pH leads to the formation of a rutile structure which is compensated for by lanthanide doping, inhibiting the anatase–rutile phase transformation. Then, the XRD profile depends on the Yb concentration, being mostly anatase for undoped and highly (8 at.%) doped samples, with mixed ratios of these two phases in other concentrations. Maintaining an acid solution leads to fewer intergrain defects in the rutile structure contributing to higher conductivity. Photo-induced investigation of 8 at.% Yb-doped thin film, using several light sources leads to distinct behavior concerning the excitation of intra-bandgap states and/or electron–hole pairs. This result helps to understand the electronic transport in Yb-doped TiO2 and shows that devices based on its conductivity may have improved performance by irradiation with controlled light energy.Department of Physics FC and POSMAT (Post-Graduate Program in Materials Science and Technology) São Paulo State University (UNESP)Brazilian Biosciences National Laboratory (LNBio) Brazilian Center for Research in Energy and Materials (CNPEM)Department of Physics FC and POSMAT (Post-Graduate Program in Materials Science and Technology) São Paulo State University (UNESP)Universidade Estadual Paulista (Unesp)Brazilian Center for Research in Energy and Materials (CNPEM)Kaezmarek Pedrini, Luiz F. [UNESP]Santos, Stevan B. O. [UNESP]Trino, Luciana D.Scalvi, Luis V. A. [UNESP]2020-12-12T01:35:58Z2020-12-12T01:35:58Z2020-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1007/s11664-020-08416-zJournal of Electronic Materials.1543-186X0361-5235http://hdl.handle.net/11449/19929610.1007/s11664-020-08416-z2-s2.0-85089857991Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal of Electronic Materialsinfo:eu-repo/semantics/openAccess2021-10-23T07:00:25Zoai:repositorio.unesp.br:11449/199296Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462021-10-23T07:00:25Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
title |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
spellingShingle |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method Kaezmarek Pedrini, Luiz F. [UNESP] phase transition photoconductivity Titanium dioxide ytterbium |
title_short |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
title_full |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
title_fullStr |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
title_full_unstemmed |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
title_sort |
Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method |
author |
Kaezmarek Pedrini, Luiz F. [UNESP] |
author_facet |
Kaezmarek Pedrini, Luiz F. [UNESP] Santos, Stevan B. O. [UNESP] Trino, Luciana D. Scalvi, Luis V. A. [UNESP] |
author_role |
author |
author2 |
Santos, Stevan B. O. [UNESP] Trino, Luciana D. Scalvi, Luis V. A. [UNESP] |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) Brazilian Center for Research in Energy and Materials (CNPEM) |
dc.contributor.author.fl_str_mv |
Kaezmarek Pedrini, Luiz F. [UNESP] Santos, Stevan B. O. [UNESP] Trino, Luciana D. Scalvi, Luis V. A. [UNESP] |
dc.subject.por.fl_str_mv |
phase transition photoconductivity Titanium dioxide ytterbium |
topic |
phase transition photoconductivity Titanium dioxide ytterbium |
description |
A method to prepare Yb-doped TiO2 is proposed, using titanium isopropoxide and ytterbium oxide. Thin films and powders are produced through the sol–gel technique where the Yb concentrations are 0.01 at.%, 0.02 at.%, 1 at.%, 2 at.% 4 at.% and 8 at.%. The increase in the doping concentration intensifies gradually the sample transparency for the whole observed spectrum and reaches the transparency degree of the undoped sample with the highest concentration of ytterbium. By means of x-ray diffraction (XRD) we find that the solution’s pH leads to the formation of a rutile structure which is compensated for by lanthanide doping, inhibiting the anatase–rutile phase transformation. Then, the XRD profile depends on the Yb concentration, being mostly anatase for undoped and highly (8 at.%) doped samples, with mixed ratios of these two phases in other concentrations. Maintaining an acid solution leads to fewer intergrain defects in the rutile structure contributing to higher conductivity. Photo-induced investigation of 8 at.% Yb-doped thin film, using several light sources leads to distinct behavior concerning the excitation of intra-bandgap states and/or electron–hole pairs. This result helps to understand the electronic transport in Yb-doped TiO2 and shows that devices based on its conductivity may have improved performance by irradiation with controlled light energy. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-12-12T01:35:58Z 2020-12-12T01:35:58Z 2020-01-01 |
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/s11664-020-08416-z Journal of Electronic Materials. 1543-186X 0361-5235 http://hdl.handle.net/11449/199296 10.1007/s11664-020-08416-z 2-s2.0-85089857991 |
url |
http://dx.doi.org/10.1007/s11664-020-08416-z http://hdl.handle.net/11449/199296 |
identifier_str_mv |
Journal of Electronic Materials. 1543-186X 0361-5235 10.1007/s11664-020-08416-z 2-s2.0-85089857991 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Journal of Electronic Materials |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
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_ |
1803046255051407360 |