Substrate dependence of InGaAs quantum dots grown by molecular beam epitaxy

A systematic study of self-organized In0.5Ga0.5As quantum dots (QDs) and is lands grown by molecular beam epitaxy on (100) and (n11) A/B GaAs substrate s is given, where n varies from 1 to 5. Low-temperature photoluminescence r esults show that the properties of the dots have a strong dependence on the substrate orientation as revealed by atomic force microscopy, consistent w ith the differences in size, shape, and distribution of QDs on different su bstrates. From (100) to (111) surface, the photoluminescence peak position of dots on B surfaces is found to blueshift more than that on A surfaces. Q Ds are also formed on (511) A surface. The positional distribution of these dots exhibits a wavy shape, which is related to the corrugated structure o f this surface. Two kinds of islands are formed on (111) A surface, but fur ther work is needed to explain the mechanism of these islands. (C) 2001 Ame rican Vacuum Society.