Optical Properties of CsI:Tl and CsBr:Tl

Abstract

Absorption, excitation and emission spectra and luminescent decay of CsI:Tl have been investigated over the temperature range from 2°K to 300°K. Six absorption bands are observed in contrast with four absorption bands A, B, C, and D in alkali halide-thallium phosphors having the NaCl structure. There exists no other absorption band having a character of the forbidden line as the B band. At 10°K, four emission bands are observed. The luminescent decay is composed of the fast and slow components and is somewhat complicated. For the purpose of comparison, the experiments on CsBr:Tl are also described.