Temperature dependence of excited-state relaxation processes of Pr3+ in Pr-doped and Pr, Gd-doped CsCdBr3

The temperature dependence and mechanisms for relaxation of the 1D2 and 3P1 states of Pr3+ in symmetrical Pr-Pr and Pr-Gd pairs in 0.12% Pr:CsCdBr3 and 0.025% Pr:1.5% Gd:CsCdBr3, respectively, are presented. Both single-ion and pair relaxation mechanisms are considered. The temperature dependences of the energy-transfer processes in Pr-Pr pairs are all well-explained in terms of resonance considerations for the donor and acceptor zero-phonon crystal-field transitions.