Spectroscopy of Nickel-Doped Zinc Sulfide Nanoparticles

In the present study, Zn1xNixS (x=0.00.8mol%) nanoparticles were prepared through the chemical route and the synthesis involved the mixing and drying of zinc acetate and sodium sulphide in an appropriate ratio with the addition of Ni2+ at a proper concentration. The structural and spectroscopic studies are investigated by X-ray diffraction (XRD), absorption spectra, emission and excitation spectra, and Raman spectra. Compared with that of the pristine materials, the absorption band-edge demonstrates an apparently blue shift, which is attributed to the quantum size effect. The average particle size of ZnS nanoparticles is in the range of 24nm deduced from the XRD line broadening. Excited at about 330nm, a blue emission band at 425nm can be observed, which corresponds to Ni2+ luminescent center; this result is consistent with the postulation that Ni2+ replaced the Zn2+ ions in the lattice of ZnS nanocrystals. Excitation spectra also confirm the above postulation. The effect of different concentrations of nickel is also studied by Raman spectra.