Temperature dependence spectroscopic study of Ce-doped Cs3LaCl6 and Cs3LaBr6 scintillators

•Temperature dependent spectroscopic study of Cs3LaX6 (X=Cl, Br) is presented.•The emission intensity of Ce-doped samples drops less than 25% from 40 K to 500 K.•The emission intensity of undoped samples indicates strong thermal quenching.•The scintillation process involves competition of self-trapped exciton and Ce3+.

Single crystals of Ce-doped Cs3LaCl6 and Cs3LaBr6 show promising scintillation properties in gamma-ray detection. Their thermal response in the range from 40 K to 500 K is discussed in this work. The steady state photoluminescence spectra, photoluminescence decay time, and X-ray excited radioluminescence of Ce-doped and undoped Cs3LaCl6 and Cs3LaBr6 were studied. The photoluminescence and radioluminescence emission intensity of the Ce-doped crystals decreases less than 25% from 40 K to 500 K. The photoluminescence decay time of Ce3+ increases with increasing temperature.