Anomalous 10-ns emission in Ce3+-doped Cs3LuCl6 -: art. no. 125108

An emission at 281 nm with a 10.5 ns single exponential decay and a highly selective, narrow excitation region between 202 and 211 nm has been observed for Ce3+ doped in Cs3LuCl6. Wavelengths between 50-200 nm and longer than 215 nm have zero excitation efficiency. Excitation and emission spectra of Cs3LuCl6:Ce3+ in the 10-300 K temperature range were excited by pulsed synchrotron radiation between 50-335 nm. In addition to this new emission, the conventional Ce3+ doublet emission from the lowest 5d level to the F-2(5/2) (368 nm) and F-2(7/2) levels (400 nm) of the 4f(1) configuration is observed. Autoionization of the 5d electron to conduction band states followed by the direct transition to the F-2 levels is proposed to explain the 281 nm emission and to explain the absence of emission under across bandgap excitation.