Identification of the I−→Pr3+ charge transfer transition in the excitation spectrum of LuI3:Pr3+

Abstract The excitation spectrum of LuI 3 :Pr 3+ is dominated by a strong ultraviolet band centered at 320 nm. This band is identified as the I − → Pr 3+ charge transfer transition. The Pr 3+ 4f 2 → 4f 1 5d 1 interconfiguration optical transitions are located within the host lattice absorption band. The luminescence of LuI 3 :Pr 3+ under charge transfer excitation is dominated by the Pr 3+ 4f 2 → 4f 2 intraconfiguration optical transitions. The absence of luminescence from the charge transfer state is due fast (nonradiative) relaxation of the charge transfer state into the Pr 3+ 4f 2 states.