Abstract: | The absorption spectra of nanosized sulfides and selenides (ZnS, CdS, CuS, Cu2S, AgS, In2S3, SnS, PbS, Sb2S3, FeS, CoS, NiS, CdSe, and Ag2Se) showed one absorption band with a maximum at wave-lengths shorter than 300 nm. The UV fluorescence spectra of all of these nanosized sulfides in a polyvinyl alcohol film contained maxima at 380–440 nm. Nanosized sulfides are thus characterized by a very large (up to 15000 cm−1) Stokes shift of fluorescence. In a polyvinyl alcohol film, a decrease in the concentration of cadmium sulfide from 0.05 to 0.002 M led to a threefold increase in the fluorescence intensity. The dependence of the degree of fluorescence buildup on the sulfide concentration is nearly linear. An increase in sulfide concentration to more than 5 × 10−3 M in solution led to a complete coagulation of particles. |