Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/326024
Type: Artigo
Title: Enhancement Of Carrier Lifetimes In Type-ii Quantum Dot/quantum Well Hybrid Structures
Enhancement of carrier lifetimes in type-II quantum dot/quantum well hybrid structures
Author: Couto Jr., O. D. D.
Almeida, P. T. de
Santos, G. E. dos
Balanta, M. A. G.
Andriolo, H. F.
Brum, J. A.
Brasil, M. J. S. P.
Iikawa, F.
Liang, B. L.
Huffaker, D. L.
Abstract: We investigate optical transitions and carrier dynamics in hybrid structures containing type-I GaAs/AlGaAs quantum wells (QWs) and type-II GaSb/AlGaAs quantum dots (QDs). We show that the optical recombination of photocreated electrons confined in the QWs with holes in the QDs and wetting layer can be modified according to the QW/QD spatial separation. In particular, for low spacer thicknesses, the QW optical emission can be suppressed due to the transference of holes from the QW to the GaSb layer, favoring the optical recombination of spatially separated carriers, which can be useful for optical memory and solar cell applications. Time-resolved photoluminescence (PL) measurements reveal non-exponential recombination dynamics. We demonstrate that the PL transients can only be quantitatively described by considering both linear and quadratic terms of the carrier density in the bimolecular recombination approximation for type-II semiconductor nanostructures. We extract long exciton lifetimes from 700 ns to 5 mu s for QDs depending on the spacer layer thickness. Published by AIP Publishing.
We investigate optical transitions and carrier dynamics in hybrid structures containing type-I GaAs/AlGaAs quantum wells (QWs) and type-II GaSb/AlGaAs quantum dots (QDs). We show that the optical recombination of photocreated electrons confined in the QWs with holes in the QDs and wetting layer can be modified according to the QW/QD spatial separation. In particular, for low spacer thicknesses, the QW optical emission can be suppressed due to the transference of holes from the QW to the GaSb layer, favoring the optical recombination of spatially separated carriers, which can be useful for optical memory and solar cell applications. Time-resolved photoluminescence (PL) measurements reveal non-exponential recombination dynamics. We demonstrate that the PL transients can only be quantitatively described by considering both linear and quadratic terms of the carrier density in the bimolecular recombination approximation for type-II semiconductor nanostructures. We extract long exciton lifetimes from 700 ns to 5 mu s for QDs depending on the spacer layer thickness.
Subject: Compostos de antimônio, Arsenieto de gálio, Pontos quânticos
Country: Estados Unidos
Editor: AIP Publishing
Citation: Journal Of Applied Physics. Amer Inst Physics, v. 120, p. , 2016.
Rights: aberto
Identifier DOI: 10.1063/1.4961534
Address: https://aip.scitation.org/doi/10.1063/1.4961534
Date Issue: 2016
Appears in Collections:IFGW - Artigos e Outros Documentos

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