Quantum dots and quantum dashes in the narrow-gap InSb/InAsSbP system

摘要

InSb quantum dots (QDs) and quantum dashes (Q-dashes) were obtained on InAs-rich substrate by both LPE and MOVPE methods. Bimodal mechanism of the formation of the InSb quantum dots was observed on InAs binary surface during the LPE growth. The low-density (5×10~8 cm~(-2)) big quantum dots with 12 nm in height and high-density (1×10~(10) cm~(-2)) small quantum dots with 4 nm in height were found to be present simultaneously. Deposition from the InSb melt over the InAs_(0.61)Sb_(0.13)P_(0.26) matrix layer lattice-matched with InAs substrate resulted in the uniformity of the InSb QDs. The Q-dashes with density (2.5×10~9 cm~(-2)) with dimensions of 30 nm in height, 500 nm in length and 200 nm in width were grown by the MOVPE method. The obtained Q-dashes were oriented along the [ 1 1 0] direction. A drastic change in the dot geometry with dependence on Ⅲ/Ⅴ ratio of the components in the vapor phase was observed. The shape and the density of the InSb Q-dashes can be determined by the surface chemistry of the InAs(Sb.P) matrix layer.