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arXiv · 1107.4121

Influence of the heterointerface sharpness on exciton recombination dynamics in an ensemble of (In,Al)As/AlAs quantum dots with indirect band-gap

T. S. Shamirzaev·J. Debus·D. S. Abramkin·D. Dunker·D. R. Yakovlev·D. V. Dmitriev·A. K. Gutakovskii·L. S. Braginsky·K. S. Zhuravlev·M. Bayer
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Abstract

The dynamics of exciton recombination in an ensemble of indirect band-gap (In,Al)As/AlAs quantum dots with type-I band alignment is studied. The lifetime of confined excitons which are indirect in momentum-space is mainly influenced by the sharpness of the heterointerface between the (In,Al)As quantum dot and the AlAs barrier matrix. Time-resolved photoluminescence experiments and theoretical model calculations reveal a strong dependence of the exciton lifetime on the thickness of the interface diffusion layer. The lifetime of excitons with a particular optical transition energy varies because this energy is obtained for quantum dots differing in size, shape and composition. The different exciton lifetimes, which result in photoluminescence with non-exponential decay obeying a power-law function, can be described by a phenomenological distribution function, which allows one to explain the photoluminescence decay with one fitting parameter only.

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T. S. Shamirzaev, J. Debus, D. S. Abramkin, D. Dunker, D. R. Yakovlev, D. V. Dmitriev, A. K. Gutakovskii, L. S. Braginsky, K. S. Zhuravlev, M. Bayer. 2011-07-20. Influence of the heterointerface sharpness on exciton recombination dynamics in an ensemble of (In,Al)As/AlAs quantum dots with indirect band-gap. https://doi.org/10.1103/physrevb.84.155318

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