Growth of high density self-assembled InAs quantum dots on As-pressure-modulated InAlAs multilayer structures on InP(001) substrate

Abstract

We have fabricated high sheet density (>1011 cm−2) InAs quantum dots (QDs) on an InAlAs buffer layer composed of As-pressure-modulated (As-rich and As-lacking) InAlAs multilayer structure (AM–InAlAs–MLS) lattice matched to InP substrate. The AM–InAlAs–MLS buffer layer has greater advantages than the conventional InAlAs buffer layer in the formation of InAs QDs, because InAs quantum wires (QWRs) are easy to obtain instead of quantum dots on InAlAs. In addition, strong radiative efficiency at room temperature (RT) can be achieved from QDs on AM–InAlAs–MLS. These results indicate that the AM–InAlAs–MLS can suppress the QWR formation and result in QD growth with high density and strong RT radiative efficiency, which is helpful for further understanding the mechanism of morphology control on the QDs.