A study was made of  the effects of Sb/As interdiffusion upon the optical anisotropy of GaSb quantum dots in GaAs. The GaSb quantum dots were grown by droplet epitaxy, and their shape was slightly elongated along [110]. Polarized photoluminescence studies showed that the photoluminescence was polarized preferentially along [110]. To induce the Sb/As interdiffusion, a post-growth annealing was performed at 600 to 950C. As Ta increases, the degree of polarization drastically decreases. The experimental results were compared with a theoretical model. The degree of polarization reduction was explained by considering the optical anisotropy of the ground and first excited states, where the contribution of the excited state increased as the diffusion proceeds.

Effects of Sb/As Interdiffusion on Optical Anisotropy of GaSb Quantum Dots in GaAs Grown by Droplet Epitaxy. T.Kawazu, T.Noda, T.Mano, Y.Sakuma, H.Sakaki: Japanese Journal of Applied Physics, 2012, 51[11], 115201