Annealing of In(0.45)Ga(0.55)As/GaAs quantum dots overgrown with large monolayer (11 ML) coverage for applications in thermally stable optoelectronic devices

Abstract

The effects of thermal annealing on the large monolayer (11 ML) coverage of In(0.45)Ga(0.55)As/GaAs quantum dots (QDs) is being investigated in this study. Low temperature (8 K) photoluminescence (PL) spectra exhibits suppressed blueshift of the strongest PL emission peak even at high temperature annealing (800 degrees C). TEM and DCXRD characterizations showed the existence of the dots with good crystalline quality at annealing temperatures of 800-850 degrees C. The physics of annealing induced compositional modification of the InGaAs QDs with various monolayer coverage has been studied by a theoretical model and simulation. All our studies establish the thermal stability of large ML coverage InGaAs QDs, which is desirable for optoelectronic devices required for selective wavelength tuning in specific applications. (C) 2011 Elsevier Ltd. All rights reserved.