Photoluminescence study of carrier transfer among vertically aligned double-stacked InAs/GaAs quantum dot layers
Yu.I. Mazur, X. Wang, Z.M. Wang, G.J. Salamo, and M. Xiao
University of Arkansas, Department of Physics, Fayetteville, Arkansas, 72701
Ferdinand-Braun-Institut für Höchstfrequenztechnik, Albert-Einstein-Straße 11, D-12489 Berlin, Germany
Published in:
Applied Physics Letters, vol. 81, no. 13, pp. 2469-2471 (2002)
© 2002 American Institute of Physics. All rights reserved.
Abstract:
Photoluminescence (PL) properties of self-organized quantum dots (QDs) in a vertically aligned
double-layer InAs/GaAs QD structure are studied as a function of temperature from 10 to 290 K.
The QDs in a sample with a 1.8 ML InAs seed layer and a second 2.4 ML InAs layer are found to
self-organize in pairs of unequal sized QDs with clearly discernible ground-states transition energy.
The unusual temperature behavior of the PL for such asymmetrical QD pairs provides clear evidence
for carrier transfer from smaller to larger QDs by means of a nonresonant multiphonon-assisted
tunneling process in the case of interlayer transfer and trough carrier thermal emission and
recapture within one layer.
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