On the decay of KCl:Cu+ fluorescence

Summary The fluorescence of Cu⁺ in KCl was investigated in the range 19–300 K, in particular by performing accurate measurements of lifetime and quantum yield. The data were found irrespective of the doping method. It was evidenced that, among the models proposed in the literature, the Pedrini model gives the most reasonable explanation for the Cu⁺ 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.