Synthesis and optical properties of cerium doped zinc sulfide nano particles

We report the synthesis of various concentrations of cerium-doped (1-4 mol%) and undoped zinc sulfide nanoparticles by co-precipitation technique at ambient condition. Powder X-ray diffraction pattern reveals both undoped and cerium doped ZnS nanoparticles are in cubic structure with slight variation in the lattice parameter due to the influence of Ce3+ ions. The average grain size of the synthesized nanoparticles was calculated to be ∼4 nm. Further the particle size, crystallinity and composition of Ce:ZnS nanoparticles were confirmed by TEM, SAED pattern and EDAX. The optical properties of the Ce:ZnS nanoparticles were characterized using UV-vis absorption and photoluminescence spectroscopy. For both undoped and doped samples, UV-vis spectra show blue shift in absorption edge as compared to bulk ZnS. Room temperature photoluminescence (PL) spectrum of the Ce3+:ZnS nanoparticles exhibits strong and stable visible-light emissions for an excitation wavelength of 290 nm. It was observed, the PL spectra of undoped sample exhibits a blue light emission peak at 427 nm and the doped sample exhibit a green emission peak at 534 nm from the 5d-4f transition along with the blue emission peak.