The mechanism of sensitized anti-stokes luminescence in crystals with adsorbed dyes

We have analyzed regular features of sensitization processes of crystals AgCl, AgCl_0.95I_0.05, and Zn_0.6Cd_0.4S to processes of a low-threshold (10^?3–10^?4 W/cm²) two-quantum excitation of anti-Stokes luminescence by adsorbed molecules and by J and H aggregates of dyes of different classes. The excitation centers of this luminescence are complex and consist of dye molecules and few-atom silver clusters adsorbed nearby. Luminescence-excitation processes involve stages of photoexcitation of adsorbed dye molecules; resonance transfer of electronic excitation energy to adsorbed atoms and few-atom silver clusters, levels of which lie near the middle of the band gap; and their subsequent photoionization.