XPS studies of the energy band structure of three Y3+-based fluoride compounds

X-ray photoelectron spectroscopy was applied to the study of the energy band structure of three Y3+-containing insulating crystals: YF3, LiYF4 and KYF4. No features were found in the photoelectron spectra of YF3 and LiYF4 which may be related to the difference in behavior of the scintillation properties of these crystals doped with rare earth ions. Comparison of the photoelectron and luminescence spectra for a KYF4 crystal, which possesses so-called crossluminescence, gave some indication for the existence of lattice relaxation in the vicinity of the long-lived K+ 3p hole.