Electrically Active States of Charge Capture and Transfer Causing Slow Recombination in Thallium-Bromide Crystals at Low Temperatures

Abstract

TlBr single crystals grown by the Bridgman–Stockbarger method are studied. It is established that frozen-conductivity effects manifest themselves under interband excitation by light at temperatures below 200 K. Herewith, clearly pronounced superlinear dependences of the induced photoconductivity on the strength of the applied electric field manifest themselves. The results of studying thermally stimulated conductivity evidence that these phenomena can be associated with the filling of trap states with thermal activation energies of 0.08–0.12 eV. This state can be removed due to thermal quenching at temperatures of ≳180 K because of the emptying of energy states with an activation energy of 0.63–0.65 eV filled after optical generation.