On the lifetime of KCI: Ag+ fluorescence

The fluorescence of Ag+ in KCI was investigated in the range 20–300 K, in particular by performing accurate lifetime measurements. It was found that, among the models proposed in the literature, the model introduced by Pedrini gives the most reasonable explanation of the Ag+ de-excitation mechanism: two excited states in thermal equilibrium are involved in the emission process, one of which is metastable and lying just below the emitting level. A discussion of the decay properties of Ag+ and Cu+ impurities in alkali halides is presented.