Atomic interdiffusion for integration of quantum dot optoelectronic devices

Abstract

The effect of interdiffusion on the luminescence of IuGaAs quantum dots grown by metal organic vapour phase epitaxy was studied. The samples were subjected to rapid thermal annealing with various capping layers. Up to 250meV blueshifts and narrowing of the linewidths by up to 60meV were observed in samples that were annealed without the dielectric cap. The capping layers created additional blueshift above that of simple thermal annealing. Ion implantation was used to create a higher density of defects in the region surrounding the dots. This led to enhanced blueshifts in the quantum dot luminescence. It was found that only low temperature anneals were required to recover the luminescence after annealing, in contrast to quantum wells which need anncaling at higher temperatures for the luminescence to be recovered. These results suggest that a range of bandgap energies could be achieved by selective area interdifhsion of the quantwn dot samples.