Effects of growth conditions on the size and density of self-assembled InAlAs/AlGaAs quantum dots grown on GaAs by molecular beam epitaxy

The effects of growth conditions on the size and density of self-assembled InAlAs/AlGaAs quantum dots (QDs) grown on GaAs by molecular beam epitaxy (MBE) were studied with an emphasis on their use for single QD spectroscopy. The effects of substrate temperature and growth rate on the density and size were found to be quite similar to those of InAs QDs on GaAs. The effect of coverage, however, was different. Although the density was relatively high as compared to that of InAs QDs, it was reduced to 1×1010 cm−2 under an optimized condition. This density is compatible with single QD spectroscopy with the help of a certain nanofabrication technique for areal restriction.