The luminescence of nanocrystalline ZnS : Mn2+ in fact exhibits a short decay time part (∼a hundred ns), but will also a long (ms) decay time is observed. The small decay time is ascribed to your defect-related emission of ZnS, and is not from your decay of the changeover of your Mn2+ impurity. The changeover of the Mn2+ features a `standard�?d