PHOTOLUMINESCENCE EMISSION OF Cu DOPED ZnS MICROSTRUCTURES SYNTHESIZED BY THERMAL EVAPORATION

Abstract

Cu doped ZnS microstructures were prepared by the thermal evaporation method using ZnS powder and CuCl2.2H2O powder as precusor materials. The microstructures was characterized by using X-ray diffraction (XRD) analysis. The XRD studies indicated that there are two phases (ZnS and ZnO) at the undoped sample, but most of the samples are only having wurtzite (hexagonal) phase of ZnS after doping. The photoluminescence emission and photoluminescence excitation of ZnS and Cu2+ doped ZnS microstructures have been studied. The photoluminescence excitation spectra of ZnS microstructures is presented around 374 nm. By doping of Cu2+ ion, the absorption wavelength is shifted towards the lower wavelength being an evidence for an increasing band gap. The emission spectrum of pure ZnS has a green emission band centred at around 520 nm. By doping Cu2+ ion, the peak of the green band in the luminescence spectra were transferred to 516 nm and appeared a strong blue peak at 440 nm. The reasons of these will be discussed in this paper.