Anomalous 10-ns emission in Ce3+-doped Cs3LuCl6

Abstract

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 2F5/2 (368 nm) and 2F7/2 levels (400 nm) of the 4f1 configuration is observed. Autoionization of the 5d electron to conduction band states followed by the direct transition to the 2F levels is proposed to explain the 281 nm emission and to explain the absence of emission under across bandgap excitation. © 2003 The American Physical Society.