ELECTRONIC STATES TUNING OF INAS SELF-ASSEMBLED QUANTUM DOTS

We demonstrate the dimensional tuning of InAs self-assembled quantum d ots (QDs) by changing the growth kinetics during the capping of InAs i slands with GaAs. Modifying the growth sequence during the capping of InAs islands, allows us to tune the thickness and lateral dimensions o f the QDs while keeping the wetting layer thickness constant. Using th e same method but embedding the tuned InAs islands into AlAs layers al lows to further blueshift the photoluminescence emission to higher ene rgies while keeping the wetting layer thickness constant. The main pro cess responsible for the QDs size modification is consistent with a ki netically controlled materials redistribution of the InAs islands that minimizes the energy of the epitaxial layers at the start up of the G aAs capping deposition. (C) 1998 American Institute of Physics.