Some Optical Properties of Potassium Iodide-Thallium Phosphors

Abstract

The absorption spectra of potassium iodide‐thallium phosphors have been studied at both liquid nitrogen and liquid helium temperatures. Eight absorption bands have been observed which are due to the presence of thallium. The maximum absorption coefficients of four of these bands appear to vary linearly, while the other four appear to vary with the square of the thallium concentration. The origin of these bands is discussed in terms of an extension of the model proposed by Seitz.