Leveling and rebuilding:: An approach to improve the uniformity of (In,Ga)As quantum dots

We report on an approach to improve the uniformity of a single layer of (In,Ga)As quantum dots (QDs) grown by molecular-beam epitaxy. The key concept of our approach is to level and rebuild the (In,Ga)As QDs during insertion of a short period GaAs/InAs superlattice between the (In,Ga)As QD layer and the GaAs capping layer. For optimized layer thickness and number of superlattice periods this process results in uniform (In,Ga)As QDs with narrow photoluminescence line width of 20 meV at 4.5 K. (C) 2002 American Institute of Physics.