Large quantum dots with small oscillator strength

S. Stobbe; T. W. Schlereth; S. Höfling; A. Forchel; J. M. Hvam; P. Lodahl

doi:10.1103/PhysRevB.82.233302

Large quantum dots with small oscillator strength

Mesoscale and Nanoscale Physics 2015-05-19 v1

Authors: S. Stobbe , T. W. Schlereth , S. Höfling , A. Forchel , J. M. Hvam , P. Lodahl

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Abstract

We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size and predict a very large oscillator strength due to Coulomb effects. This is in stark contrast to the measured oscillator strength, which turns out to be much below the upper limit imposed by the strong confinement model. We attribute these findings to exciton localization in local potential minima arising from alloy intermixing inside the quantum dots.

Keywords

quantum dots excitons in semiconductors

Cite

@article{arxiv.1006.5796,
  title  = {Large quantum dots with small oscillator strength},
  author = {S. Stobbe and T. W. Schlereth and S. Höfling and A. Forchel and J. M. Hvam and P. Lodahl},
  journal= {arXiv preprint arXiv:1006.5796},
  year   = {2015}
}

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4 pages, 3 figures, submitted

Large quantum dots with small oscillator strength

Abstract

Keywords

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