PHOTOELECTRON-SPECTROSCOPIC STUDY OF CORE-EXCITON DECAY IN AUGER-FREE LUMINESCENCE MATERIAL BaF₂

Abstract

The nonradiative decay processes of the Ba-5p core exciton in BaF2 have been investigated by using photoelectron spectroscopy, since the exciton peak is missing in the excitation spectrum of the Auger-free luminescence. The decay probability of the direct recombination process estimated from the constant-initial state spectrum and the absorption coefficient was found to be smaller than unity, indicating the existence of the other decay processes. It is suggested that the Ba-5p core exciton is relaxed by about 0.9 eV.