Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise
Ano de defesa: | 2016 |
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Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Dissertação |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal de São Carlos
Câmpus São Carlos |
Programa de Pós-Graduação: |
Programa de Pós-Graduação em Física - PPGF
|
Departamento: |
Não Informado pela instituição
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País: |
Não Informado pela instituição
|
Palavras-chave em Português: | |
Palavras-chave em Inglês: | |
Área do conhecimento CNPq: | |
Link de acesso: | https://repositorio.ufscar.br/handle/ufscar/8774 |
Resumo: | We report a systematic study on the structural, morphological and optical properties of Zn1−xCoxO thin films grown by spray pyrolysis. The employed nominal concentrations were up to 15 Co %. The films were deposited on glass substrates between 220-300 o C using precursors such as zinc acetate and cobalt acetate in aqueous solutions. The effects of Co-doping on structural, morphological and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical transmittance and absorbance as well as photoluminescence (PL). The XRD results indicated that all films are polycrystalline with wurtzite crystal structure, a preferential growth direction in c-axis, and no secondary phases. SEM images generally showed uniform surface, and few regions have irregularities due to effects of the inclusion of cobalt as well as substrate deposition temperature. The spectra of transmittance and absorbance exhibited the transitions d-d due to Co2+ ion, a redshift of the absorption-edge and changes in the absorption band intensity with increasing of nominal Co-doping. These observations revealed the substitution of Zn ions Zn2+ and the presence of Co in the state 2+ in tetrahedral coordination in the ZnO lattice. Furthermore, there was a narrowing in band gap of 28 meV by percentage of Co inserted into the lattice. The PL spectra of ZnCoO samples presented three bands associated to near-band-edge absorption (NBE), structural defects and intratomic emissions of Co2+. Their optical emissions were characterized by the presence of traps which capture carriers and affect significantly the emissions. Through a qualitative model in a temperature range we interpreted these traps as potential fluctuations up to 17 meV. We also discussed the annealing in selected samples. |
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Repositório Institucional da UFSCAR |
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Onofre Ramirez, Yina JuliethGodoy, Marcio Peron Franco dehttp://lattes.cnpq.br/2609654784637427http://lattes.cnpq.br/24540485149420662017-05-25T19:51:05Z2017-05-25T19:51:05Z2016-03-09ONOFRE RAMIREZ, Yina Julieth. Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise. 2016. Dissertação (Mestrado em Física) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8774.https://repositorio.ufscar.br/handle/ufscar/8774We report a systematic study on the structural, morphological and optical properties of Zn1−xCoxO thin films grown by spray pyrolysis. The employed nominal concentrations were up to 15 Co %. The films were deposited on glass substrates between 220-300 o C using precursors such as zinc acetate and cobalt acetate in aqueous solutions. The effects of Co-doping on structural, morphological and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical transmittance and absorbance as well as photoluminescence (PL). The XRD results indicated that all films are polycrystalline with wurtzite crystal structure, a preferential growth direction in c-axis, and no secondary phases. SEM images generally showed uniform surface, and few regions have irregularities due to effects of the inclusion of cobalt as well as substrate deposition temperature. The spectra of transmittance and absorbance exhibited the transitions d-d due to Co2+ ion, a redshift of the absorption-edge and changes in the absorption band intensity with increasing of nominal Co-doping. These observations revealed the substitution of Zn ions Zn2+ and the presence of Co in the state 2+ in tetrahedral coordination in the ZnO lattice. Furthermore, there was a narrowing in band gap of 28 meV by percentage of Co inserted into the lattice. The PL spectra of ZnCoO samples presented three bands associated to near-band-edge absorption (NBE), structural defects and intratomic emissions of Co2+. Their optical emissions were characterized by the presence of traps which capture carriers and affect significantly the emissions. Through a qualitative model in a temperature range we interpreted these traps as potential fluctuations up to 17 meV. We also discussed the annealing in selected samples.Apresentamos um estudo sistemático sobre as propriedades estruturais, morfológicas e ópticas de filmes Zn1−xCoxO com concentrações nominais de Co até 15% obtidos por spray pirólise. Os filmes foram depositados sobre substratos de vidro entre 220 - 300 oC, utilizando como precursores acetato de zinco e acetato de cobalto em solução aquosa. Os efeitos da dopagem com Co nas propriedades estruturais, morfológicas e ópticas foram estudados por difração de raios-X (DRX), microscopia eletrônica de varredura (MEV), transmitância e absorbância óptica, e fotoluminescência (PL). Os resultados de DRX indicaram que todos os filmes são policristalinos, com estrutura cristalina do tipo wurtzita e direção de crescimento preferencial no eixo c, com ausência de fases secundárias. As imagens do MEV, em geral, mostraram que as superfícies são uniformes, com irregularidades em algumas regiões devido aos efeitos da inserção de Cobalto e da temperatura de deposição do substrato. Nos espectros de transmitância e absorbância, observaram-se a presença das transições d-d do íon de Co2+, o deslocamento da borda de absorção para baixas energias, e a variação da intensidade da banda de absorção das transições d-d com o aumento da dopagem nominal de Co. Estas observações revelaram a substituição dos íons de Zn2+ e a presença de Co no estado +2 na coordenação tetraédrica na rede do ZnO. Além disso, houve uma redução da energia do bandgap de 28 meV por porcentagem de Co inserido na rede. Os espectros de PL das amostras de ZnO dopado com Co apresentaram três bandas associadas à emissão próxima à borda de absorção óptica, defeitos estruturais e emissão intratômica do Co2+. A emissão óptica dos filmes foi caracterizada pela presença de armadilhas que localizam os portadores de carga e afetam significativamente as bandas de emissão no intervalo de temperatura estudado. Através de um modelo qualitativo interpretamos estas armadilhas como flutuações de potencial com profundidades de até 17 meV. Discutimos também o tratamento térmico em amostras selecionadas.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Física - PPGFUFSCarSemicondutor magnético diluídoÓxido de zincoSpintrônicaSpray piróliseDiluted magnetic semiconductorZinc oxideSpintronicSpray pyrolysisCIENCIAS EXATAS E DA TERRA::FISICASíntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray piróliseinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisOnlineinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALDissYJOR.pdfDissYJOR.pdfapplication/pdf3749771https://{{ getenv "DSPACE_HOST" "repositorio.ufscar.br" }}/bitstream/ufscar/8774/1/DissYJOR.pdf98b6729837eaa69cb6eb598ad207cfcfMD51LICENSElicense.txtlicense.txttext/plain; charset=utf-81957https://{{ getenv "DSPACE_HOST" "repositorio.ufscar.br" }}/bitstream/ufscar/8774/2/license.txtae0398b6f8b235e40ad82cba6c50031dMD52TEXTDissYJOR.pdf.txtDissYJOR.pdf.txtExtracted texttext/plain132990https://{{ getenv "DSPACE_HOST" "repositorio.ufscar.br" }}/bitstream/ufscar/8774/3/DissYJOR.pdf.txt19852e2e51b4b0eff64ab27d19125595MD53THUMBNAILDissYJOR.pdf.jpgDissYJOR.pdf.jpgIM Thumbnailimage/jpeg6478https://{{ getenv "DSPACE_HOST" "repositorio.ufscar.br" }}/bitstream/ufscar/8774/4/DissYJOR.pdf.jpgd800d9e3401a57cc71d2a25ad986b79cMD54ufscar/87742019-09-11 03:53:51.034oai:repositorio.ufscar.br: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Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-05-25T12:54:12.178940Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
title |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
spellingShingle |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise Onofre Ramirez, Yina Julieth Semicondutor magnético diluído Óxido de zinco Spintrônica Spray pirólise Diluted magnetic semiconductor Zinc oxide Spintronic Spray pyrolysis CIENCIAS EXATAS E DA TERRA::FISICA |
title_short |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
title_full |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
title_fullStr |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
title_full_unstemmed |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
title_sort |
Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise |
author |
Onofre Ramirez, Yina Julieth |
author_facet |
Onofre Ramirez, Yina Julieth |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/2454048514942066 |
dc.contributor.author.fl_str_mv |
Onofre Ramirez, Yina Julieth |
dc.contributor.advisor1.fl_str_mv |
Godoy, Marcio Peron Franco de |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/2609654784637427 |
contributor_str_mv |
Godoy, Marcio Peron Franco de |
dc.subject.por.fl_str_mv |
Semicondutor magnético diluído Óxido de zinco Spintrônica Spray pirólise |
topic |
Semicondutor magnético diluído Óxido de zinco Spintrônica Spray pirólise Diluted magnetic semiconductor Zinc oxide Spintronic Spray pyrolysis CIENCIAS EXATAS E DA TERRA::FISICA |
dc.subject.eng.fl_str_mv |
Diluted magnetic semiconductor Zinc oxide Spintronic Spray pyrolysis |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::FISICA |
description |
We report a systematic study on the structural, morphological and optical properties of Zn1−xCoxO thin films grown by spray pyrolysis. The employed nominal concentrations were up to 15 Co %. The films were deposited on glass substrates between 220-300 o C using precursors such as zinc acetate and cobalt acetate in aqueous solutions. The effects of Co-doping on structural, morphological and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical transmittance and absorbance as well as photoluminescence (PL). The XRD results indicated that all films are polycrystalline with wurtzite crystal structure, a preferential growth direction in c-axis, and no secondary phases. SEM images generally showed uniform surface, and few regions have irregularities due to effects of the inclusion of cobalt as well as substrate deposition temperature. The spectra of transmittance and absorbance exhibited the transitions d-d due to Co2+ ion, a redshift of the absorption-edge and changes in the absorption band intensity with increasing of nominal Co-doping. These observations revealed the substitution of Zn ions Zn2+ and the presence of Co in the state 2+ in tetrahedral coordination in the ZnO lattice. Furthermore, there was a narrowing in band gap of 28 meV by percentage of Co inserted into the lattice. The PL spectra of ZnCoO samples presented three bands associated to near-band-edge absorption (NBE), structural defects and intratomic emissions of Co2+. Their optical emissions were characterized by the presence of traps which capture carriers and affect significantly the emissions. Through a qualitative model in a temperature range we interpreted these traps as potential fluctuations up to 17 meV. We also discussed the annealing in selected samples. |
publishDate |
2016 |
dc.date.issued.fl_str_mv |
2016-03-09 |
dc.date.accessioned.fl_str_mv |
2017-05-25T19:51:05Z |
dc.date.available.fl_str_mv |
2017-05-25T19:51:05Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
ONOFRE RAMIREZ, Yina Julieth. Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise. 2016. Dissertação (Mestrado em Física) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8774. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/8774 |
identifier_str_mv |
ONOFRE RAMIREZ, Yina Julieth. Síntese e caracterização de filmes do sistema Zn(1−x)CoxO obtidos por spray pirólise. 2016. Dissertação (Mestrado em Física) – Universidade Federal de São Carlos, São Carlos, 2016. Disponível em: https://repositorio.ufscar.br/handle/ufscar/8774. |
url |
https://repositorio.ufscar.br/handle/ufscar/8774 |
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por |
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por |
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info:eu-repo/semantics/openAccess |
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openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Física - PPGF |
dc.publisher.initials.fl_str_mv |
UFSCar |
publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
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Repositório Institucional da UFSCAR |
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