Effect of different strain reducing layers on InAs quantum dots grown by migration enhanced epitaxy

We investigated the effect of InGaAs and AlGaAs combination strain reducing layers on InAs quantum dots (QDs) grown by migration enhanced epitaxy. The samples were examined by cross-sectional transmission electron microscopy, low-temperature and power dependent photoluminescence (PL). We observed three different size distributions of QDs in the atomic force microscopy image. We found that PL peak 1, 2, and 3 came from three different size distributions, and the energy level of QDs could be modified by changing strain reducing layers irrelevantly to controlling QD height in our samples. Furthermore, we elucidated the role of InGaAs and AlGaAs layer on the energy level modification and related cross-sectional morphology of the QDs.