Photophysical Properties of ZnS Nanoclusters with Spatially Localized Mn2

The synthesis and photophysical characterization of nanometer-size ZnS with and without Mn2+ are reported. Without Mn2+, the ZnS nanoclusters emit in the blue upon ultraviolet excitation. ZnS doped with 1−5% Mn2+ (presumably in Zn2+ sites) yields the orange emission observed for bulk Zn:Mn phosphors but with greatly reduced emissive lifetimes. ZnS with surface-bound Mn2+, in contrast, emits in the ultraviolet with even shorter lifetimes. Thus, the physical location of Mn2+ in the ZnS nanocluster determines its optical properties.