Analysis of the effect of annealing on the photoluminescence spectra of Cu+ ion implanted ZnS nanoparticles

► Photoluminescence (PL) study of nanoparticles of ZnS implanted with Cu+ ions at the doses of 5×1014, 1×1015 and 5×1015 ions/cm2 and annealed at 200 and 300 °C is reported. ► The PL emission peak around 485 nm is attributed to the transition of electrons from conduction band of ZnS to the impurity level formed by the implanted Cu+ ions. ► The observation of copper ion impurity related peak at 490 nm in the PL spectra of samples of the present study indicates that the doping of copper ions into the ZnS lattice is achievable by implanting Cu+ ions followed by annealing.