Extremely low density InAs quantum dots realized in situ on (100) GaAs

Abstract

Extremely low density self-assembled InAs quantum dots are grown by acombination technique of in situ annealing for 2 min and pause of substraterotation during molecular beam epitaxy. The surface morphology and structuralcharacteristics of the quantum dots are scrutinized by atomic force microscopy andphotoluminescence spectra. It is found that the quantum dot size and densityincrease as the InAs deposition amount rises. Quantum dots with a density between2.5 × 107 cm−2 and 2.2 × 108 cm−2 are 2–5 nm in height and 18–39 nm in diameter. It is believed that as-grown InAs nanodotsmay be of important value for future single quantum dot research.