Exciton localization effect in Mn-implanted GaN by photoluminescence measurements

We investigated the temperature-dependent and excitation power-dependent photoluminescence spectra of Mn-implanted (Ga,Mn)N samples with five Mn-implantation doses. The near-band-energy emission was observed and was attributed to the Mn-related exciton transition, which exhibits localized exciton behaviour resulting from alloy potential fluctuations and demonstrates a special temperature-dependence characteristic of alloy disorder. In terms of the integrated photoluminescence intensity as a function of temperature, the activation energy of the localized exciton was obtained. All these results show strong dependence on the Mn concentration of (Ga,Mn)N epilayers.