Photoelectron spectroscopic study of decay process of Li1s—core exciton in LiF

The decay process of the Li $1s$—core exciton in LiF was investigated by means of photoelectron spectroscopy. The enhancement of the intensities of the valence band and the Auger peak was observed at the photon energy corresponding to the excitation energy of the Li $1s$—core exciton. Two nonradiative decay processes of the core exciton, $K\left(\mathrm{e}\mathrm{x}\mathrm{c}\mathrm{i}\mathrm{t}\mathrm{o}\mathrm{n}\right)-V$ process and $K\left(\mathrm{exciton}\right)-VV$ process, were proposed to interpret the resonant behavior in the constant-initial-state spectrum with the initial state at the peak of the valence band and in the constant-final-state spectrum with the final state corresponding to the kinetic energy of the Auger electron. It was also suggested that, in the $K\left(\mathrm{exciton}\right)-VV$ process, which is a predominant nonradiative decay process in LiF, the excited electron in a bound state affects the kinetic energy of the Auger electron.