Dependence of the efficiency of various emissions on excitation density in BaF 2 crystals

Abstract

The dependence of the intensity of the emission of self-trapped excitons, crossluminescence (CL) and intraband luminescence on the excitation density in BaF 2 by electron pulses (300 keV , 3 ns ) has been studied. The energy input above 2×10 19 eV cm −3 causes quenching of 5.5 eV CL due to the recombination of conduction electrons with the outermost-core holes resulting in the formation of cation excitons and the subsequent energy transfer from a cation exciton to a valence electron of a neighbouring anion. The excitation spectra for various fast (τ<5 ns) and inertial emissions have been measured using synchrotron radiation at 9 K .