Connections between Color Center Phenomena and Luminescence Phenomena in General

Abstract

Alkali halide research has occupied a central position in solid‐state physics. Its teachings are transferable to other fields. A modern synthesis of alkali halide research relevant to luminescence phenomena in general is presented. The relationship between the mechanisms of coloration and luminescence in alkali halides is described. The concepts of nonmoving excitons and of self‐trapping are discussed and used to explain intrinsic luminescence in all alkali halides and the scintillation mechanism in thallium‐activated alkali halides in an atomistic way. The possible importance of self‐trapping, lattice relaxation, internal metastable states, molecules in crystals, etc., in the luminescence of some conventional phosphors is pointed out.