Centers of near-IR luminescence in bismuth-doped TlCl and CsI crystals

A comparative first-principles study of possible bismuth-related centers in TlCl and CsI crystals is performed and the results of computer modeling are compared with the experimental data. The calculated spectral properties of the bismuth centers suggest that the IR luminescence in TlCl:Bi is most likely caused by Bi+ center dot center dot center dot V-Cl(-) centers (Bi+ ion in thallium site and a negatively charged chlorine vacancy in the nearest anion site). On the contrary, Bi+ substitutional ions and Bi-2(+) dimers are most likely responsible for the IR luminescence in CsI:Bi. (C) 2013 Optical Society of America