Effect of proton-irradiation on photoluminescence emission from self-assembled InAs/GaAs quantum dots

A study of the effects of proton-irradiation of InAs/GaAs quantum dots (QDs) is presented. The samples are simple GaAs-capped, single layer of InAs quantum dots, grown on GaAs substrates by molecular beam epitaxy. Using proton implantation (10 keV to I MeV protons, dose of up to I X 10(13)/cm(2)) and photoluminescence (PL) spectroscopy at 25 K, we discuss the influence of proton-irradiation upon the photoluminescence degradation or enhancement of quantum dots. In general, we find the PL efficiency enhancement occurs when the dose is about the same order of magnitude as the average QD density and it occurs when the average separation between proton passage is about twice the QD size. The QDs must be annealed of radiation-damage of a size in 15 nm range to maximize PL efficiency. (c) 2007 Elsevier B.V. All rights reserved.