The effects of rapid thermal annealing on doubled quantum dots grown by molecular beam epitaxy

The effects of different rapid thermal annealing temperatures on the optical properties of InAs double quantum dots (DQDs) grown by molecular beam epitaxy using a partial-capping-and-regrowth process have been investigated. Improvement of the material quality is indicated by enhanced photoluminescence (PL) intensity and narrower PL linewidth. The blueshift of the PL emission peak with increasing annealing temperature is due to the interdiffusion of group III atoms during the annealing process, which is confirmed by the temperature dependence of the PL peak position. Thermal quenching of the PL intensity is observed at temperature over 110 K, and the main activation energy decreases with annealing temperature, consistent with a reduced confining potential from the interdiffusion of group III atoms. All of these results are similar to those of single quantum dots reported in the literature.