A-luminescence in CsI:Tl crystal excited by pulsed electron beam

Abstract

The amplitude-time parameters of the A-luminescence at 3.12 eV are studied for CsI:Tl irradiated by a pulsed electron beam at temperatures 77–295 K. It has been established that the 3.12 eV band kinetics varies differently with temperature in two temperature ranges of 77–170 K and 170–295 K. The increase in temperature from 77 K to 170 K causes the decrease in the exponential decay time constant, while at temperatures above 170 K, there appeared the post-radiation rise stage followed by the slow exponential decay stage. The temperature behavior of the A-luminescence kinetics is interpreted in term of the model, according to which (i) the A band is due to the allowed electron transition 61P1 → 61S0 of Tl+ ions and (ii) the main excitation mechanism across the entire cathodoluminescence spectrum of CsI:Tl at temperatures near room temperature is the spontaneous disinteтgration of donor–acceptor dipoles [Tl0Vk].