Effects of thermal annealing on Ga0.3In0.7NxAs1-x QDs grown on GaAs [001]

Effects of thermal annealing on Ga_0.3In_0.7N_xAs_1-x quantum dots (QDs) grown on GaAs [001] have been investigated. The improvement of the optical properties of Ga_0.3In_0.7N_xAs_1-x QDs is observed as a result of rapid thermal annealing or in situ annealing. In general, increasing annealing time or temperature improves the photoluminescence (PL) intensity but results in a blue shift of the peak due to interdiffusion of Ga and In. However, when the annealing time is short and annealing temperature is low enough to prevent the interdiffusion, the PL intensity can be increased without a blue shift of the peak. The improvement of the PL intensity of Ga_0.3In_0.7N_xAs_1-x QDs is much more than that of GaInAs QDs, because the N-containing sample has many more non-radiative recombination centers such as point defects, which can be reduced by thermal annealing.