The effect of concentration of Dy3+ ions on luminescence properties of Y2O2S:Dy3+, Mg2+, Ti4+ phosphors

Abstract Y 2 O 2 S:Dy 3+ , Mg 2+ , Ti 4+ white-light long-lasting phosphors were synthesized by the sol–gel method. The effect of Dy 3+ doping concentration on the luminescence properties was investigated. The samples were characterized by X-ray diffraction, photoluminescence spectroscopy and thermally stimulated spectrometry. The samples doped with different concentrations of Dy 3+ ions were composed of the pure Y 2 O 2 S phase. Under 359 nm UV excitation, the phosphor presented white luminescence due to mixing of the dominating emissions centered at 488 nm (blue) and 579 nm (yellow), corresponding to 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions of Dy 3+ , respectively. When Dy 3+ concentration was 1 mol%, the CIE chromaticity diagram was (0.375,0.374), and the decay time could last for over 65 min (≥1 mcd/m 2 ).