Vacuum ultraviolet and visible spectra of Eu3+ in Y2O2S and Eu2O2S

The vacuum ultraviolet excitation spectrum and visible luminescence spectra of Y2O2S:Eu 3+ (10 at.%) and Eu2O2S are reported and assigned. Excitation bands peaking at 312 nm (3.97 eV) and 244 nm (5.08 eV) are assigned to S-3p and O-2p to Eu 3+ charge transfer absorptions. The bands peaking at 175 nm (7.08 eV) and 224 nm (5.54 eV) are due to absorption from the valence band dominated by O-2p orbitals to the different Y-4d conduction bands. The absorptions from the valence band dominated by S-3p orbitals to the conduction bands are weaker.