Fluorescence Decay Lifetime of Ultrafine CdS and ZnS Particles

The fluorescence decay properties of CdS and ZnS ultrafine particles have been investigated by a single photon counting technique. We have found that the decay is dependent on the particle size, emission wavelength and colloidal sandwich structure. Shorter emission lifetimes were observed for smaller CdS particles and at shorter emission wavelength. The average emission lifetime of ZnS part in the sandwich structure of ZnS and CdS particles clearly decreased.