The nature of Bi3+ luminescence in the double perovskite, La2LiSbO6

We have examined the luminescence of Bi3+ (6s2) in La2LiSbO6 which is a monoclinic distorted double (ordered) perovskite. The optical properties of Bi3+ can be rationalized in terms of the localized 3P0,1→1S0 emission transition. There is no evidence for emission from the D-state despite the presence of Sb5+ with the 4d105s0 electronic configuration. Band structure calculations were performed to determine the composition of the conduction band. A comparative study of Bi3+ luminescence in several perovskites containing cations with nd0 and nd10 electronic configuration show that composition of the conduction band makes an important contribution to the occurrence or lack thereof of the D-state emission. A comparative study of the temperature dependence of the Bi3+ luminescence efficiency in La2LiSbO6 and CaZrO3 leads to the tentative conclusion that thermally activated crossover from the Bi3+ 6s16p1 excited state to the 6s2 ground state is responsible for the quenching of Bi3+ luminescence in these perovskites.