Enhanced radiation hardness of photoluminescence from InAs quantum dots embedded in an AlAs/GaAs superlattice structure

摘要

We report a study of proton irradiation effects on the luminescence of self-assembled InAs quantum dots (QDs) embedded in an AlAs/GaAs short-period superlattice structure. As opposed to the QDs grown in a GaAs thin film, the QDs embedded in an AlAs/GaAs superlattice structure were found to exhibit much higher photoluminescence (PL) degradation resistance to proton irradiation. For example, at the highest dose (10~(14) cm~(-2)) used in this work, the PL intensity from the QDs in superlattice dropped by a factor of ～4, while the PL intensity from the QDs in GaAs decreased by almost two orders of magnitude, relative to their respective as-grown samples. Effects of thermal annealing on the luminescence of irradiated QDs were also examined. Possible mechanisms leading to the enhanced PL radiation hardness for QDs in superlattice are discussed.