Photoluminescent Efficiency of Phosphors with Electronic Transitions in Localized Centers

No general theory exists that can predict the efficiency of phosphors with electronic transitions in localized centers. In this paper a survey and discussion are given of the correlation between fluorescent properties and chemical properties, like composition and structure. Points of discussion are ( a ) choice of the activator together with concentration quenching and critical concentration for this phenomenon, ( b ) influence of the host lattice on the photoluminescence efficiency for direct excitation of the activator, and ( c ) energy transfer between fluorescent centers. These considerations are illustrated by a large number of experimental examples.