Effect of thermal annealing in the microstructural and the optical properties of uncapped InAs quantum dots grown on GaAs buffer layers

摘要

The effect of thermal annealing on self-assembled uncapped InAs/GaAs quantum dots (QDs) has been investi2ated using transmission electron microscopy (TEM) and photolurninescence (PL) measurement. The TEM images showed that the lateral sizes and densities of the InAs QDs were not changed significantly up to 6-50degreesC. When the InAs/GaAs QDs were annealed at 700 degreesC, while the lateral size of the InAs QDs increased. their density decreased. The InAs QDs disappeared at 800 degreesC. PL spectra showed that the peaks corresponding to the interband transitions of the InAS QDs shifted slightly toward the high-energy side, and the PL intensity decreased with increasing annealing temperature. These results indicate that the microstructural and the optical properties of self-assembled uncapped InAs/GaAs can he modified due to postgrowth thermal annealing. (C) 2005 Elsevier Ltd. All rights reserved.