InAs/GaAs QUANTUM DOTS COVERED BY GaAsSb STRAIN REDUCING LAYER

We have prepared and studied InAs/GaAs quantum dots (QDs) by the Metalorganic Vapour Phase Epitaxy in Stranski-Krastanow self-organized growth mode at temperature 510 °C and covered by GaAsSb strain reducing layer (SRL). We found out that for higher temperature (510° C) the Sb incorporation into the SRL is decreased. Two explanations are suggested: first the higher strain on the apex of bigger QDs, second increased Sb surfacting on the growth surface. However, unincorporated surfacting Sb atoms also prevent QDs dissolution. Increased QD size together with decreased Sb incorporation helped us to obtain type I [1] QD structure with long wavelength emission at 1400 nm.