Luminescent Homoatomic Exciplexes in Dicyanoargentate(I) Ions Doped in Alkali Halide Crystals. 2. “Exciplex Tuning” by Varying the Dopant Concentration

The dependence of the dicyanoargentate(I) luminescence on the dopant concentration in [Ag(CN) 2 - ]/KCl single crystals is reported. Three crystals with different Ag content have been studied. The photoluminescence spectrum of the doped crystal that has the lowest silver content (0.17%) is dominated by a high-energy band at ∼295 nm, while the spectrum with the highest silver content (4.3%) is dominated by a low-energy luminescence band at ∼400 nm. The crystal with an intermediate Ag content (2.7%) shows strong emissions from both the high-energy and low-energy bands. Time-resolved luminescence measurements indicate that the excitation energy is transferred between different [Ag(CN) 2 - ] n oligomers and, thus, leads to the tunable emission observed in the [Ag(CN) 2 - ]/KCl system. The mechanisms of the radiative and nonradiative processes have been described by a kinetic model that describes the experimental lifetime and time-resolved data.