Photoluminescence of Eu^(2+)Doped ZnS Nanocrystals

Eu^(2+)doped ZnS nanocrystals exhibit new luminescence properties because of the enlarged energy gap of nanocrys talline ZnS host due to quantum confinement effects.Photoluminescence emission at about 520nm from Eu^(2+)doped ZnS nanocrystals at room temperature is investigated by using photoluminescence emission and excitation spectroscopy.Such green emission with long lifetime(ms)is proposed to be a result of excitation,ionization,carriers recapture and recombination via Eu^(2+)centers in nanocrystalline ZnS host.