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Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation

In this study, the two-photon excited fluorescence spectra from cadmium selenide quantum dots (QDs) on a silicon nitride photonic crystal (PhC) membrane under femtosecond laser irradiation were investigated. These spectra can be fit to a tri-Gaussian function in which one component is negative in am...

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Autor principal: Xu, Xingsheng
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4047539/
https://www.ncbi.nlm.nih.gov/pubmed/24902925
http://dx.doi.org/10.1038/srep05039
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author Xu, Xingsheng
author_facet Xu, Xingsheng
author_sort Xu, Xingsheng
collection PubMed
description In this study, the two-photon excited fluorescence spectra from cadmium selenide quantum dots (QDs) on a silicon nitride photonic crystal (PhC) membrane under femtosecond laser irradiation were investigated. These spectra can be fit to a tri-Gaussian function in which one component is negative in amplitude, and in which the Gaussian components with positive amplitude are assigned to exciton emission and charged-exciton emission and that with negative amplitude is assigned to absorption from surface recombination. The photonic crystal enhance the charged-exciton emission and exciton emission and, at the same time, also the absorption from surface recombination. Both the charged-exciton emission and the surface recombination are related to Auger recombination; therefore, the photonic crystal controls both radiative recombination and non-radiative recombination. The asymmetries of the two-photon excited fluorescence spectra are due to not only the location of the resonant guide mode of the PhC slab but also the enhancement of the absorption from surface recombination by PhC.
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spelling pubmed-40475392014-06-12 Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation Xu, Xingsheng Sci Rep Article In this study, the two-photon excited fluorescence spectra from cadmium selenide quantum dots (QDs) on a silicon nitride photonic crystal (PhC) membrane under femtosecond laser irradiation were investigated. These spectra can be fit to a tri-Gaussian function in which one component is negative in amplitude, and in which the Gaussian components with positive amplitude are assigned to exciton emission and charged-exciton emission and that with negative amplitude is assigned to absorption from surface recombination. The photonic crystal enhance the charged-exciton emission and exciton emission and, at the same time, also the absorption from surface recombination. Both the charged-exciton emission and the surface recombination are related to Auger recombination; therefore, the photonic crystal controls both radiative recombination and non-radiative recombination. The asymmetries of the two-photon excited fluorescence spectra are due to not only the location of the resonant guide mode of the PhC slab but also the enhancement of the absorption from surface recombination by PhC. Nature Publishing Group 2014-06-06 /pmc/articles/PMC4047539/ /pubmed/24902925 http://dx.doi.org/10.1038/srep05039 Text en Copyright © 2014, Macmillan Publishers Limited. All rights reserved http://creativecommons.org/licenses/by/3.0/ This work is licensed under a Creative Commons Attribution 3.0 Unported License. The images in this article are included in the article's Creative Commons license, unless indicated otherwise in the image credit; if the image is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the image. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/
spellingShingle Article
Xu, Xingsheng
Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
title Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
title_full Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
title_fullStr Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
title_full_unstemmed Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
title_short Surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
title_sort surface recombination and charged exciton in nanocrystal quantum dots on photonic crystals under two-photon excitation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4047539/
https://www.ncbi.nlm.nih.gov/pubmed/24902925
http://dx.doi.org/10.1038/srep05039
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