Preparation and photoluminescent properties of doped nanoparticles of ZnS by solid-state reaction

Nanometer-sized Eu(3+)-doped ZnS and Mn(2+)-doped ZnS particles were prepared by solid-state method at low temperature. The structures and properties of those materials were characterized by X-ray diffraction (XRD) and photoluminescent spectroscopy techniques. The XRD patterns reveal that the doped ZnS nanoparticles belong to zinc-blende structure. The concentration of doping ions has little effect on the sizes of the doped ZnS nanoparticles, which mainly depends on the temperature of preparation. The emission peaks from the (5)D(0) -> (7)F(j) (J = 1, 2, and 4) electronic energy transitions of Eu(3+) were observed in the emission spectra of the ZnS:Eu(3+) nanoparticles. The intensity ratio of the two peaks from the (5)D(0) -> (7)F(1) and (5)D(0) -> (7)F(2) transitions indicates that more Eu(3+) ions occupy the sites with no inversion symmetry. For the ZnS:Mn(2+) nanoparticles, an orange emission from the (4)T(1) -> (6)A(1) transition of Mn(2+) is present, indicating that the doping ions occupy the positions of the ZnS lattices. Meanwhile, UV-induced luminescence enhancement was observed for the ZnS:Mn(2+) nanoparticles, the possible reason of which is discussed primarily. (C) 2009 Elsevier B.V. All rights reserved.