Photoluminescence characteristics of ZnS nanocrystallites co-doped with Co~(2+) and Cu~(2+)

摘要

Zinc sulfide (ZnS) nanoparticles co-doped with Cu~(2+) and Co~(2+) have been prepared by precipitation from homogeneous solutions of zinc, copper and cobalt salt compounds, with S~92-) as precipitating anion formed by decomposition of thoacetamide. X-ray diffraction shows that the average crystallite size of doped and undoped ZnS nanometer-scale samples is about 2-3 nm. Novel luminescence characteristics (strong and stable visible emission #lambad#_em approx 515-560 nm) have been obseved for the co-doped ZnS nanocrystals at room temperature. The relative fluoresence intensity of the co-doped sample is dramatically higher than that of undoped ZnS nanocrystallites. The emission wavelength of the co-doped samples varies with change in the impurity mole ratio of Cu~(2+) and Co~(2+).