Quenching of exciton decay processes in UV-irradiated KI

Abstract

Irradiation of KI in the fundamental edge results in a growth of F centres (and V centres) predominantly proportional to the square root of the number of photons incident on the crystal. Irradiation in the same region at lower temperatures results in the well-known intrinsic KI luminescence. This luminescence is found to be quenched in UV colored crystals. Both phenomona are interpreted as resulting from the return of the crystal to its initial state via an interaction whose probability is proportional to the concentration of F centres.