Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects
- Autores
- Aguirre, Matías Ezequiel; Municoy, Sofia; Grela, Maria Alejandra; Colussi, A.j.
- Año de publicación
- 2017
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- The unique properties of semiconductor quantum dots (QDs) have found application in the conversion of solar to chemical energy. How the relative rates of the redox processes that control QD photon efficiencies depend on the particle radius (r) and photon energy (Eλ), however, is not fully understood. Here, we address these issues and report the quantum yields (Φs) of interfacial charge transfer and electron doping in ZnO QDs capped with ethylene glycol (EG) as a function of r and Eλ in the presence and absence of methyl viologen (MV2+) as an electron acceptor, respectively. We found that Φs for the oxidation of EG are independent of Eλ and photon fluence (φλ), but markedly increase with r. The independence of Φs on φλ ensures that QDs are never populated by more than one electron-hole pair, thereby excluding Auger-type terminations. We show that these findings are consistent with the operation of an interfacial redox process that involves thermalized carriers in the Marcus inverted region. In the absence of MV2+, QDs accumulate electrons up to limiting volumetric densities ρe,∞ that depend sigmoidally on excess photon energy E∗ = Eλ - EBG(r), where EBG(r) is the r-dependent bandgap energy. The maximum electron densities: ρev,∞ ∼ 4 × 1020 cm-3, are reached at E∗ > 0.5 eV, independent of the particle radius.
Fil: Aguirre, Matías Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina
Fil: Municoy, Sofia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Grela, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina
Fil: Colussi, A.j.. California Institute Of Technology; Estados Unidos - Materia
-
SEMICONDUCTOR
QUANTUM DOTS
PHOTODOPING
SIZE - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
- Repositorio
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/77630
Ver los metadatos del registro completo
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Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effectsAguirre, Matías EzequielMunicoy, SofiaGrela, Maria AlejandraColussi, A.j.SEMICONDUCTORQUANTUM DOTSPHOTODOPINGSIZEhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The unique properties of semiconductor quantum dots (QDs) have found application in the conversion of solar to chemical energy. How the relative rates of the redox processes that control QD photon efficiencies depend on the particle radius (r) and photon energy (Eλ), however, is not fully understood. Here, we address these issues and report the quantum yields (Φs) of interfacial charge transfer and electron doping in ZnO QDs capped with ethylene glycol (EG) as a function of r and Eλ in the presence and absence of methyl viologen (MV2+) as an electron acceptor, respectively. We found that Φs for the oxidation of EG are independent of Eλ and photon fluence (φλ), but markedly increase with r. The independence of Φs on φλ ensures that QDs are never populated by more than one electron-hole pair, thereby excluding Auger-type terminations. We show that these findings are consistent with the operation of an interfacial redox process that involves thermalized carriers in the Marcus inverted region. In the absence of MV2+, QDs accumulate electrons up to limiting volumetric densities ρe,∞ that depend sigmoidally on excess photon energy E∗ = Eλ - EBG(r), where EBG(r) is the r-dependent bandgap energy. The maximum electron densities: ρev,∞ ∼ 4 × 1020 cm-3, are reached at E∗ > 0.5 eV, independent of the particle radius.Fil: Aguirre, Matías Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Municoy, Sofia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grela, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Colussi, A.j.. California Institute Of Technology; Estados UnidosRoyal Society of Chemistry2017-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/77630Aguirre, Matías Ezequiel; Municoy, Sofia; Grela, Maria Alejandra; Colussi, A.j.; Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects; Royal Society of Chemistry; Physical Chemistry Chemical Physics; 19; 6; 1-2017; 4494-44991463-9076CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1039/C6CP06829Dinfo:eu-repo/semantics/altIdentifier/url/https://pubs.rsc.org/en/content/articlelanding/2017/CP/C6CP06829Dinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:35:14Zoai:ri.conicet.gov.ar:11336/77630instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:35:14.385CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
dc.title.none.fl_str_mv |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
title |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
spellingShingle |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects Aguirre, Matías Ezequiel SEMICONDUCTOR QUANTUM DOTS PHOTODOPING SIZE |
title_short |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
title_full |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
title_fullStr |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
title_full_unstemmed |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
title_sort |
Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects |
dc.creator.none.fl_str_mv |
Aguirre, Matías Ezequiel Municoy, Sofia Grela, Maria Alejandra Colussi, A.j. |
author |
Aguirre, Matías Ezequiel |
author_facet |
Aguirre, Matías Ezequiel Municoy, Sofia Grela, Maria Alejandra Colussi, A.j. |
author_role |
author |
author2 |
Municoy, Sofia Grela, Maria Alejandra Colussi, A.j. |
author2_role |
author author author |
dc.subject.none.fl_str_mv |
SEMICONDUCTOR QUANTUM DOTS PHOTODOPING SIZE |
topic |
SEMICONDUCTOR QUANTUM DOTS PHOTODOPING SIZE |
purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
dc.description.none.fl_txt_mv |
The unique properties of semiconductor quantum dots (QDs) have found application in the conversion of solar to chemical energy. How the relative rates of the redox processes that control QD photon efficiencies depend on the particle radius (r) and photon energy (Eλ), however, is not fully understood. Here, we address these issues and report the quantum yields (Φs) of interfacial charge transfer and electron doping in ZnO QDs capped with ethylene glycol (EG) as a function of r and Eλ in the presence and absence of methyl viologen (MV2+) as an electron acceptor, respectively. We found that Φs for the oxidation of EG are independent of Eλ and photon fluence (φλ), but markedly increase with r. The independence of Φs on φλ ensures that QDs are never populated by more than one electron-hole pair, thereby excluding Auger-type terminations. We show that these findings are consistent with the operation of an interfacial redox process that involves thermalized carriers in the Marcus inverted region. In the absence of MV2+, QDs accumulate electrons up to limiting volumetric densities ρe,∞ that depend sigmoidally on excess photon energy E∗ = Eλ - EBG(r), where EBG(r) is the r-dependent bandgap energy. The maximum electron densities: ρev,∞ ∼ 4 × 1020 cm-3, are reached at E∗ > 0.5 eV, independent of the particle radius. Fil: Aguirre, Matías Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina Fil: Municoy, Sofia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Grela, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina Fil: Colussi, A.j.. California Institute Of Technology; Estados Unidos |
description |
The unique properties of semiconductor quantum dots (QDs) have found application in the conversion of solar to chemical energy. How the relative rates of the redox processes that control QD photon efficiencies depend on the particle radius (r) and photon energy (Eλ), however, is not fully understood. Here, we address these issues and report the quantum yields (Φs) of interfacial charge transfer and electron doping in ZnO QDs capped with ethylene glycol (EG) as a function of r and Eλ in the presence and absence of methyl viologen (MV2+) as an electron acceptor, respectively. We found that Φs for the oxidation of EG are independent of Eλ and photon fluence (φλ), but markedly increase with r. The independence of Φs on φλ ensures that QDs are never populated by more than one electron-hole pair, thereby excluding Auger-type terminations. We show that these findings are consistent with the operation of an interfacial redox process that involves thermalized carriers in the Marcus inverted region. In the absence of MV2+, QDs accumulate electrons up to limiting volumetric densities ρe,∞ that depend sigmoidally on excess photon energy E∗ = Eλ - EBG(r), where EBG(r) is the r-dependent bandgap energy. The maximum electron densities: ρev,∞ ∼ 4 × 1020 cm-3, are reached at E∗ > 0.5 eV, independent of the particle radius. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-01 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
format |
article |
status_str |
publishedVersion |
dc.identifier.none.fl_str_mv |
http://hdl.handle.net/11336/77630 Aguirre, Matías Ezequiel; Municoy, Sofia; Grela, Maria Alejandra; Colussi, A.j.; Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects; Royal Society of Chemistry; Physical Chemistry Chemical Physics; 19; 6; 1-2017; 4494-4499 1463-9076 CONICET Digital CONICET |
url |
http://hdl.handle.net/11336/77630 |
identifier_str_mv |
Aguirre, Matías Ezequiel; Municoy, Sofia; Grela, Maria Alejandra; Colussi, A.j.; Low intensity, continuous wave photodoping of ZnO quantum dots - Photon energy and particle size effects; Royal Society of Chemistry; Physical Chemistry Chemical Physics; 19; 6; 1-2017; 4494-4499 1463-9076 CONICET Digital CONICET |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/doi/10.1039/C6CP06829D info:eu-repo/semantics/altIdentifier/url/https://pubs.rsc.org/en/content/articlelanding/2017/CP/C6CP06829D |
dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
eu_rights_str_mv |
openAccess |
rights_invalid_str_mv |
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
dc.format.none.fl_str_mv |
application/pdf application/pdf application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Royal Society of Chemistry |
publisher.none.fl_str_mv |
Royal Society of Chemistry |
dc.source.none.fl_str_mv |
reponame:CONICET Digital (CONICET) instname:Consejo Nacional de Investigaciones Científicas y Técnicas |
reponame_str |
CONICET Digital (CONICET) |
collection |
CONICET Digital (CONICET) |
instname_str |
Consejo Nacional de Investigaciones Científicas y Técnicas |
repository.name.fl_str_mv |
CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas |
repository.mail.fl_str_mv |
dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar |
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1844613096229830656 |
score |
13.070432 |