J. Grimm, J. Fleniken, K. W. Krämer, D. Biner, U. Happek and H. U. Güdel
On the determination of photoionization thresholds of Ce³⁺ doped Cs₃LuCl₆, Cs₂LiLuCl₆ and Cs₂LiYCl₆ by thermoluminescence
J. Lumin. 122-123, 325-328 (2007)                 

Abstract: We report on photoionization measurements of three Ce³⁺ doped chlorides: Cs₃LuCl₆, Cs₂LiLuCl₆ and Cs₂LiYCl₆. These chlorides are hygroscopic and must be kept hermetically sealed in quartz vials, complicating the use of standard techniques to determine electron transfer processes. Thus, a solely optical technique, based on thermoluminescence excitation spectroscopy, is applied to detect the photoionization energies of Ce³⁺ in the three compounds.