Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials

Detalhes bibliográficos
Ano de defesa: 2025
Autor(a) principal: GONÇALVES, Igor Macêdo
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Tese
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Pernambuco
UFPE
Brasil
Programa de Pos Graduacao em Fisica
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
CdSe nanoplatelets
CdSe/CdS core/shell 2D nanostructures
Halide perovskites
Z-scan technique
Optical Kerr Gate (OKG)
Nonlinear optical characterization
Link de acesso: https://repositorio.ufpe.br/handle/123456789/64817
Resumo: The nonlinear optical (NLO) properties of semiconductor nanomaterials are of growing interest due to their relevance in ultrafast photonics and optoelectronic applications. In this work, we investigate the third-order and higher-order NLO responses of colloidal cadmium selenide (CdSe) nanoplatelets (NPLs) and core/shell CdSe/CdS structures in toluene using femtosecond Z-scan and optical Kerr gate (OKG) techniques. Our results reveal strong agreement between both methods and demonstrate complex intensity-dependent behavior, including sign reversal in nonlinear refraction and evidence of effective three-photon absorption. Time-resolved measurements show ultrafast orientational dynamics, with sub-picosecond responses modulated by nanostructure design. Under resonant excitation, both saturable absorption and enhanced self-focusing effects were observed, particularly in CdSe NPLs. The CdSe/CdS core/shell structures exhibit broader absorption features and higher saturation thresholds, indicative of inhomogeneous broadening. Comparatively, CsPbBr3 halide perovskite quantum dots show strong Kerr-type nonlinearities at low intensities, which saturate under stronger excitation due to excitonic state filling and strong nonlinear solvent contribution. These findings highlight the crucial role of quantum confinement and structural engineering in optimizing nonlinear optical behavior, providing insights for the development of advanced photonic materials.
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spelling Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterialsCdSe nanoplateletsCdSe/CdS core/shell 2D nanostructuresHalide perovskitesZ-scan techniqueOptical Kerr Gate (OKG)Nonlinear optical characterizationThe nonlinear optical (NLO) properties of semiconductor nanomaterials are of growing interest due to their relevance in ultrafast photonics and optoelectronic applications. In this work, we investigate the third-order and higher-order NLO responses of colloidal cadmium selenide (CdSe) nanoplatelets (NPLs) and core/shell CdSe/CdS structures in toluene using femtosecond Z-scan and optical Kerr gate (OKG) techniques. Our results reveal strong agreement between both methods and demonstrate complex intensity-dependent behavior, including sign reversal in nonlinear refraction and evidence of effective three-photon absorption. Time-resolved measurements show ultrafast orientational dynamics, with sub-picosecond responses modulated by nanostructure design. Under resonant excitation, both saturable absorption and enhanced self-focusing effects were observed, particularly in CdSe NPLs. The CdSe/CdS core/shell structures exhibit broader absorption features and higher saturation thresholds, indicative of inhomogeneous broadening. Comparatively, CsPbBr3 halide perovskite quantum dots show strong Kerr-type nonlinearities at low intensities, which saturate under stronger excitation due to excitonic state filling and strong nonlinear solvent contribution. These findings highlight the crucial role of quantum confinement and structural engineering in optimizing nonlinear optical behavior, providing insights for the development of advanced photonic materials.As propriedades ópticas não lineares (NLO) de nanomateriais semicondutores têm despertado interesse crescente devido à sua relevância em fotônica ultrarrápida e aplicações optoeletrônicas. Nesta tese, investigamos as respostas NLO de terceira ordem e de ordens superiores de nanoplaquetas coloidais de seleneto de cádmio (CdSe) e de estruturas núcleo/casca CdSe/CdS em tolueno, utilizando as técnicas de varredura-Z com pulsos de femtossegundos e efeito Kerr ótico (OKG). Nossos resultados revelam uma forte concordância entre ambos os métodos e demonstram um comportamento complexo dependente da intensidade, incluindo inversão de sinal na refração não linear e evidências de absorção efetiva de três fótons. Medidas resolvidas no tempo mostram dinâmicas orientacionais ultrarrápidas, com respostas em escala sub-picosegundo moduladas pelo design das nanoestruturas. Sob excitação ressonante, foram observados efeitos de absorção saturável e autofocalização intensificada, especialmente nas nanoplaquetas de CdSe. As estruturas núcleo/casca de CdSe/CdS exibem características de absorção mais amplas e limiares de saturação mais elevados, indicativos de alargamento inhomogêneo. Comparativamente, pontos quânticos de perovskita haleto CsPbBr3 mostram forte não linearidade do tipo Kerr em baixas intensidades, que satura sob excitação mais intensa devido ao preenchimento dos estados excitônicos e forte efeito não-linear do solvente. Esses achados destacam o papel crucial do confinamento quântico e da engenharia estrutural na otimização do comportamento óptico não linear, oferecendo subsídios para o desenvolvimento de materiais fotônicos avançados.Universidade Federal de PernambucoUFPEBrasilPrograma de Pos Graduacao em FisicaGOMES, Anderson Stevens Leônidashttp://lattes.cnpq.br/4253574469931673http://lattes.cnpq.br/8841334894205599GONÇALVES, Igor Macêdo2025-08-04T13:25:28Z2025-08-04T13:25:28Z2025-06-27info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfGONÇALVES, Igor Macêdo. Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials. 2025. Tese (Doutorado em Física) – Universidade Federal de Pernambuco, Recife, 2025.https://repositorio.ufpe.br/handle/123456789/64817porhttps://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFPEinstname:Universidade Federal de Pernambuco (UFPE)instacron:UFPE2025-08-10T17:56:52Zoai:repositorio.ufpe.br:123456789/64817Repositório InstitucionalPUBhttps://repositorio.ufpe.br/oai/requestattena@ufpe.bropendoar:22212025-08-10T17:56:52Repositório Institucional da UFPE - Universidade Federal de Pernambuco (UFPE)false
dc.title.none.fl_str_mv Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
title Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
spellingShingle Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
GONÇALVES, Igor Macêdo
CdSe nanoplatelets
CdSe/CdS core/shell 2D nanostructures
Halide perovskites
Z-scan technique
Optical Kerr Gate (OKG)
Nonlinear optical characterization
title_short Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
title_full Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
title_fullStr Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
title_full_unstemmed Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
title_sort Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials
author GONÇALVES, Igor Macêdo
author_facet GONÇALVES, Igor Macêdo
author_role author
dc.contributor.none.fl_str_mv GOMES, Anderson Stevens Leônidas
http://lattes.cnpq.br/4253574469931673
http://lattes.cnpq.br/8841334894205599
dc.contributor.author.fl_str_mv GONÇALVES, Igor Macêdo
dc.subject.por.fl_str_mv CdSe nanoplatelets
CdSe/CdS core/shell 2D nanostructures
Halide perovskites
Z-scan technique
Optical Kerr Gate (OKG)
Nonlinear optical characterization
topic CdSe nanoplatelets
CdSe/CdS core/shell 2D nanostructures
Halide perovskites
Z-scan technique
Optical Kerr Gate (OKG)
Nonlinear optical characterization
description The nonlinear optical (NLO) properties of semiconductor nanomaterials are of growing interest due to their relevance in ultrafast photonics and optoelectronic applications. In this work, we investigate the third-order and higher-order NLO responses of colloidal cadmium selenide (CdSe) nanoplatelets (NPLs) and core/shell CdSe/CdS structures in toluene using femtosecond Z-scan and optical Kerr gate (OKG) techniques. Our results reveal strong agreement between both methods and demonstrate complex intensity-dependent behavior, including sign reversal in nonlinear refraction and evidence of effective three-photon absorption. Time-resolved measurements show ultrafast orientational dynamics, with sub-picosecond responses modulated by nanostructure design. Under resonant excitation, both saturable absorption and enhanced self-focusing effects were observed, particularly in CdSe NPLs. The CdSe/CdS core/shell structures exhibit broader absorption features and higher saturation thresholds, indicative of inhomogeneous broadening. Comparatively, CsPbBr3 halide perovskite quantum dots show strong Kerr-type nonlinearities at low intensities, which saturate under stronger excitation due to excitonic state filling and strong nonlinear solvent contribution. These findings highlight the crucial role of quantum confinement and structural engineering in optimizing nonlinear optical behavior, providing insights for the development of advanced photonic materials.
publishDate 2025
dc.date.none.fl_str_mv 2025-08-04T13:25:28Z
2025-08-04T13:25:28Z
2025-06-27
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv GONÇALVES, Igor Macêdo. Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials. 2025. Tese (Doutorado em Física) – Universidade Federal de Pernambuco, Recife, 2025.
https://repositorio.ufpe.br/handle/123456789/64817
identifier_str_mv GONÇALVES, Igor Macêdo. Nonlinear photonics in CdSe-based nanoplatelets and related colloidal nanomaterials. 2025. Tese (Doutorado em Física) – Universidade Federal de Pernambuco, Recife, 2025.
url https://repositorio.ufpe.br/handle/123456789/64817
dc.language.iso.fl_str_mv por
language por
dc.rights.driver.fl_str_mv https://creativecommons.org/licenses/by-nc-nd/4.0/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/4.0/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidade Federal de Pernambuco
UFPE
Brasil
Programa de Pos Graduacao em Fisica
publisher.none.fl_str_mv Universidade Federal de Pernambuco
UFPE
Brasil
Programa de Pos Graduacao em Fisica
dc.source.none.fl_str_mv reponame:Repositório Institucional da UFPE
instname:Universidade Federal de Pernambuco (UFPE)
instacron:UFPE
instname_str Universidade Federal de Pernambuco (UFPE)
instacron_str UFPE
institution UFPE
reponame_str Repositório Institucional da UFPE
collection Repositório Institucional da UFPE
repository.name.fl_str_mv Repositório Institucional da UFPE - Universidade Federal de Pernambuco (UFPE)
repository.mail.fl_str_mv attena@ufpe.br
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