Luminescence of CsBr:Tl crystals under synchrotron excitation

Time-resolved emission and excitation spectra of CsBr:Tl crystals have been measured at 9 K under excitation in the 4.0-21 eV energy range. The origin of the high-energy excitation bands located in the 5.4-6.7 eV range has been discussed. It could be concluded that the strongly overlapping B and C bands of a Tl+ ion, D bands, arising from the exciton transitions perturbed by the Tl+ ion, and charge-transfer bands are located in this range. The ultraviolet A emission of Tl+ ions (3.65 and 3.48 eV) is mainly excited in the A, B, C and D bands, while the visible localized exciton emission (2.87 and 2.42 eV), in the charge-transfer bands.