Influence of halogenides on luminescence from silver molecular clusters in photothermorefractive glasses

It is shown experimentally that a rise in the sodium halogenide (NaCl, NaBr) concentration in photothermorefractive glasses increases the intensity of luminescence from silver neutral molecular clusters. Substitution of NaBr for NaCl with their concentration being the same shifts the luminescence band toward longer waves and raises its intensity. These findings can be explained by the formation of molecular clusters of type Ag$_n$-Hal (Hal = Cl, Br) in photothermorefractive glass.