Effect of Erbium Complexes on the Anti-Stokes Luminescence of Y 2 O 2 S:Er Ceramics

— Emission spectra of Y 2 O 2 S:Er (1 at %) ceramics and decay times of their visible photoluminescence have been studied at different pulsed IR excitation wavelengths. The results demonstrate that the visible anti-Stokes luminescence of the erbium-doped material is due to isolated Er 3+ ions or complexes of erbium ions. We have obtained characteristic emission centers of the complexes and isolated erbium centers. A method has been proposed for selective delayed luminescence measurements in order to separate the contributions of various erbium centers to anti-Stokes emission of Y 2 O 2 S:Er.