Formation of ultrahigh-density InAs/AlAs quantum dots by metalorganic chemical vapor deposition

摘要

High-density InAs quantum dots (QDs) were grown on an AlAs matrix layer by metalorganic chemical vapor deposition. The effects of various growth parameters were systematically studied by atomic force microscopy. The AlAs layer was essential for obtaining high-density QDs, with densities as high as 4.7×10~(11) cm~(-2). We have also demonstrated the effects of a thin GaAs insertion layer to prevent aluminum intermixing and to block some defects, which occurred on the GaAs buffer layer. As a result, the photoluminescence intensity of InAs/GaAs/AlAs QD structures was improved by two orders of magnitude.