Very weak temperature quenching in orange luminescence of ZnS:Mn2+ nanocrystals in polymer

A polyvinyl alcohol film containing ZnS:Mn2+ nanocrystals is prepared by a chemical method, and the temperature dependence of the Mn2+ luminescence intensity is investigated in the 9–305 K range. Under the interband excitation of the ZnS host crystals, the temperature quenching of the Mn2+ luminescence in the nanocrystals is found to be remarkably weak in comparison with the commercially available bulk powder. Probable causes of this difference are discussed in terms of the thermally induced dissociation of the exciton, the exciton-phonon interaction, and the rate of the energy transfer from the exciton to the Mn2+ ion.