Energy transfer in LiCaAlF6:Ce3+

Time-resolved X-ray excited luminescence, induced absorption and thermostimulated luminescence in pure and Ce-doped LiCaAlF6 crystals have been investigated. It was found that the Ce-doped samples have a fast rise time and a 25 ns decay time following pulsed photoexcitation and a 6 ns rise time and a 50 ns decay time following pulsed X-ray excitation. This may be connected with the transport and sequential capture of charge carriers at or near the Ce3+ ion. The overlapping self-trapped exciton emission (280 nm) and Ce3+ ion absorption (270 nm) bands also makes excitonic energy transfer possible. Shallow and deep traps were found in the LiCaAlF6:Ce3+ crystals.