We investigate indium interdiffusion in InAs/(AlGa)As self-assembled quantu
m dots by studying the changes in the optical properties of the system indu
ced by ion implantation and/or thermal annealing. Interdiffusion of In-Ga a
nd In-Al atoms at the interface between the dot and the (AlGa)As barrier ta
kes place in as-grown samples and is enhanced by the postgrowth treatments.
In contrast to the proposed interdiffusion as the way for suppressing the
optical emission from the wetting layer, we show that it drives the system
towards a predominantly two-dimensional morphology. (C) 2001 American Insti
tute of Physics.