Luminescence properties of white-light long-lasting phosphor Y2O2S:Dy3+, Mg2+, Si4+

A series of novel Y2O2S:Dy3+, Mg2+, Si4+ white-light long-lasting phosphors were synthesized by the solid-state reaction method. The Y2O2S:Dy3+, Mg2+, Si4+ phosphors were characterized by X-ray diffraction, photoluminescence and long-lasting phosphorescence spectra, and thermoluminescence curves. The samples doped with different concentrations of Dy3+ ions were composed of the pure Y2O2S phase. Under 357 nm UV excitation, the emission peaks at 486 nm and 577 nm were assigned to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ respectively. When Dy3+ concentration was 1%, the CIE chromaticity diagram was (0.28, 0.28), and the decay time could last for over 36 min (≥1 mcd/m2).