A New Method of Preparing Strongly Luminescent Thallium Activated Alkali Halides and Some Properties of These Phosphors

Abstract

Phosphors with a bright visible fluorescence and a long lasting afterglow can be prepared by grinding potassium chloride with small amounts of a thallous salt in a mortar. The character of the luminescence spectra and the phosphorescence decay depends on the thallium concentration. The behavior of other alkali halides under the same treatment and some conclusions concerning the probable carriers of the luminescence are discussed.