M. D. Birowosuto, P. Dorenbos, J. T. M. de Haas, C. W. E. van Eijk, K. W. Krämer and H. U. Güdel
Optical spectroscopy and luminescence quenching of LuI₃:Ce³⁺
J. Lumin. 118, 308-316 (2006)                 

Abstract: Optical spectroscopy of LuI₃ doped with Ce³⁺ using ultraviolet and visible light excitation is reported. LuI₃ host excitation and emission and 4f–5d excitation and emission of Ce³⁺ are observed. An empirical model based on crystal field splitting was used to estimate the energy of the highest 4f–5d excitation band. The crystal field splitting and centroid shift were compared to those of LuCl₃:Ce³⁺ and LuBr₃:Ce³⁺. Temperature dependence of X-ray excited luminescence spectra shows thermal quenching, whereas that of the decay curve of Ce³⁺ emission excited at the lowest 5d band of Ce³⁺ does not indicate the presence of quenching of Ce³⁺ emission for temperature below 625 K. The quenching in LuI₃:Ce³⁺ therefore occurs before the 5d Ce³⁺ emission takes place.