Effects of Sb-soak on InAs quantum dots grown on (001) and (113)B GaAs substrates

We have investigated the effects of Sb-soak on InAs quantum dots (QDs) grown on (001) and (113)B GaAs substrates by molecular beam epitaxy. Surface morphologies of the QDs were characterized by atomic force microscopy. The optical properties of buried QDs were investigated by photoluminescence (PL). We showed that effects of Sb-soak on density and PL of (001) and (113)B QDs were quite different. The increased density and blue-shift of (001) QDs can be explained by the surfactant effect of Sb atoms which increase the areal density of the kinks for nucleation. On the other hand, for (113)B QDs, the incorporation effect should be responsible for the red-shift because the Sb atoms may be diffused into QDs.