High index orientation effects of strained self-assembled InGaAs quantum dots

Abstract

Optical characterization of strained InGaAs/GaAs quantum dots grown by molecular beam epitaxy on (001) and (n11)B, where n=1, 2, 3, 5, and 7 orientations is reported in this work. Quantum dot photoluminescence emission shows remarkable orientation effects, presented in peak shape, full width at half-maximum, and integrated intensity. Quantum dots grown on the (711)B plane demonstrate high quantum efficiency: integrated photoluminescence ratio between quantum dots and quantum well is about 10. Our results indicate an enhancement of the quantum dots onset thermal quenching energy by a factor of 2.5 for all orientations. Activation energy for thermal stimulated electron–hole emission in quantum dots is 2–5 times higher than in quantum wells. Photoluminescence polarization measurements show strong in-plane dependence caused by the quantum dots’ structural anisotropy.