Luminescence excitation spectra of TbX3 (X=Cl−, Br−, I−)

Abstract A systematic study of the excitation spectrum of TbX3 (X = Cl−, Br−, I−) is presented in this work. In general, the excitation spectra of TbX3 can be divided into three major regions: (1) the short-wave host lattice absorption region, (2) the intermediate absorption region where the Tb3+ 4f8 → 4f75d1 interconfigurational excitation transition are located, and (3) the long-wave excitation region where the Tb3+ 4f8 → 4f8 intraconfigurational excitation transition are located. The high spin and the low spin components of the Tb3+ interconfigurational excitation transition are clearly identified in the case of TbCl3. The luminescence of TbX3 (X = Cl−, Br−, I−) is dominated by emission transitions emanating from the Tb3+ 5D4 state. A comparative study of the optical properties of TbX3 (X = Cl−, Br−, I−) with the properties of the Tb3+ ion in several halide host lattices is presented. Further, a comparative study of the fundamental host lattice optical transitions in terbium halides and other halide materials is also presented.