Effects of ${\hbox {Na}}^ + $, ${\hbox {Mg}}^{2+} $ , ${\hbox {Ca}}^{2+} $,

Roy H.P. Awater,Karl Wilhelm Kramer,Pieter Dorenbos

The effects of Na⁺, Mg^{2 +}, Ca^{2 +}, Sr^{2 +} and Ba^{2 +} doping on the scintillation properties of CeBr₃ are evaluated in this paper. Ca^{2 +} and Sr^{2 +} doped CeBr₃ show different scintillation properties as compared to undoped CeBr₃, i.e. an additional perturbed Ce^{3 +} site with emission maxima red-shifted by 30 nm compared to unperturbed Ce^{3 +} sites as evidenced by X-ray excited emission and photoluminescence measurements. Also a nearly constant light yield at temperatures below 300 K, an increased decay time and the appearance of multiple glow peaks in thermoluminescence measurements are observed for Ca and Sr doped CeBr₃. These effects on the scintillation properties of CeBr₃ are explained using a single trap model where Br vacancies, formed as charge compensation for the aliovalent dopants, act as electron traps.