On the luminescence of selenium(IV) in A2ZrCl6 (A=Cs, Rb)

Luminescence spectra and decay times of the Se4+ ion in A2ZrCl2 (A=Cs, Rb) are presented. The luminescence intensity and decay time measurements provide evidence for the presence of two different minima on the adiabatic potential energy surface of the 3A1u and 3T1u relaxed excited states, although only emission from one of these minima could be observed. The excitation spectra of the Se4+ luminescence reveal a dynamical Jahn-Teller effect in the 3T1u excited state. The 1A1g→3T1u transitio situated at 26000 cm−1, the 1A1g→1T1u transition at 32700 cm−1. A comparison is made with the luminescence of Cs2NaSc Cs2NaYCl6:Sb3+ and Cs2ZrCl6:Te4+.