Strain compensation effect on stacked InAs self-assembled quantum dots embedded in GaNAs layers

Abstract

ABSTRACTWe have studied the effect of strain compensation in multiple stacking of InAs self-assembled quantum dots on GaAs (001) substrates grown by atomic hydrogen assisted RF-molecular beam epitaxy. The GaNxAs1−x material was used as a strain compensating spacer layer. We confirmed by high resolution x-ray diffraction measurements that a 40 nm GaN0.005As0.995 strain compensating layer provides compressive strain to compensate for tensile strain induced by 2.0 ML InAs quantum dots. Consequently, we achieved a multiple stack of InAs QDs up to 30 layers without formation of coalesced QDs, and the density of QDs exceeded 1012 cm−2.