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Free keywords:
photoluminescence; InAs; self-assembled quantum dots; molecular beam epitaxy
Abstract:
The effects of desorption and diffusion of indium adatoms on
the photoluminescence (PL) front InAs self-assembled quantum
dots (QDs) are investigated by introducing growth interruptions
after QD formation, Large, low-density and small. high-density
QDs were grown by molecular beam epitaxy using low (0.01 ML/s)
and high (0.2 ML/s) growth rates, respectively. The PL from the
QDs grown at 0.01 ML,s and with various growth interruption
times exhibit decreasing linewidths front 40 to 32 meV with
increasing growth interruption tine up to 30 s. The narrowing
of the PL linewidth results from improved size homogeneity due
to desorption and diffusion of adatonts, from small (< 30 nm)
InAs clusters, The narrowing of the PL linewidth front the InAs
dots is combined with low-temperature GaAs capping to obtain a
linewidth of 26 meV. (C) 2002 Elsevier Science B.V. All rights
reserved.
