Thumbnail
Access Restriction
Open

Author Couto, 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.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ ALUMINIUM ARSENIDES ♦ CARRIER DENSITY ♦ CARRIER LIFETIME ♦ ELECTRONS ♦ GALLIUM ANTIMONIDES ♦ GALLIUM ARSENIDES ♦ LAYERS ♦ PHOTOLUMINESCENCE ♦ QUANTUM DOTS ♦ QUANTUM WELLS ♦ RECOMBINATION ♦ SEMICONDUCTOR MATERIALS ♦ THICKNESS ♦ TIME RESOLUTION ♦ TRANSIENTS
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 μs for QDs depending on the spacer layer thickness.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-08-28
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 120
Issue Number 8


Open content in new tab

   Open content in new tab