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 in tensity is investigated in the 9-305 K range. Under the interband excitatio n of the ZnS host crystals, the temperature quenching of the Mn2+ luminesce nce in the nanocrystals is found to be remarkably weak in comparison with t he commercially available bulk powder. Probable causes of this difference a re discussed in terms of the thermally induced dissociation of the exciton, the exciton-phonon interaction, and the rate of the energy transfer from t he exciton to the Mn2+ ion. (C) 2000 Elsevier Science B.V. All rights reser ved.