Ultrafast core-to-core luminescence in BaF2 - LaF3 single crystals

Abstract

Abstract This study investigates the mechanisms underlying the ultrafast cross-luminescence observed in BaF 2 crystals doped with LaF 3 . We identified an ultrafast luminescent component with a decay time of approximately 150 ps, which emerges under excitation energies exceeding 24 eV as a novel radiative recombination process between electrons in the 5p core band of Ba 2+ and holes in the 5p core band of La 3+ . Ab initio calculations supported this hypothesis, showing that the energy levels of the core bands facilitate such transitions. The findings indicated that BaF 2 -LaF 3 scintillators hold significant promise for the detection of ultrafast processes in high-energy physics and medical applications.