The effect of proton implantation on photoluminescence from ensembles of InAs quantum dots embedded in GaAs

The light-emission efficiency of InAs/GaAs quantum dots (QDs) affected by proton implantation and subsequent annealing is investigated. The photoluminesce (PL) intensity is determined by the carrier capture time and non-radiative center (NRC) lifetime. The intermixing-induced carrier capture enhancement and the implantation-induced NRC generation mutually compete, so there exists a critical implantation dose (Phi c). When Phi is less than Phi c, the intermixing is the main effect and the PL intensity increases with Phi. On the other hand, when Phi is larger than Phi c, the implantation damage is so large that the intensity decreases with the dose. The higher the annealing temperature is, the larger Phi c becomes.