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
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/77630
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/77630
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling 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 Técnicas2025-10-22T11:03:15Zoai: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:34982025-10-22 11:03:16.258CONICET 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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score 12.982451

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