Synthesis and characterization of Cu doped ZnS nanoparticles by wet chemical method

The synthesis of undoped ZnS and Cu doped ZnS have been carried out by wet chemical method at room temperature. The as-prepared ZnS and ZnS:Cu nanoparticles are characterized using X-ray diffraction, UV-Vis spectrophotometer and photoluminescence spectroscopy. The size of the synthesized nanoparticles is found to be in 2.5 nm range. The band-gap is found to be higher indicating blue shift compared with that of the bulk ZnS which is attributed to quantum size effect. Room temperature photoluminescence spectrum of the undoped sample exhibits a blue emission peaked at 430 nm whereas Cu doped sample exhibits the blue emission of ZnS and a green emission peaked at 520 nm under the same UV excitation.