Decay of fluorescence emission of KI: Cu+

Summary Lifetime and quantum yield measurements concerning the fluorescence of Cu⁺ impurity centre in KI were performed in the range 19–300 K. The emission mechanism was shown to involve two excited states in thermal equilibrium, one of them being metastable and lying close under the emitting level,i.e. according to the Pedrini model for Cu⁺ fluorescence in alkali halides.