Luminescence improvement of Y2O2S:Tb3+, Sr2+, Zr4+ white-light long-lasting phosphor via Eu3+ addition

In order to improve the luminescence properties of Y2O2S: Tb3+, Sr2+, Zr4+, the Eu3+ ions doped Y2O2S:Tb3+, Sr2+, Zr4+ white-light long-lasting phosphors were synthesized by the solid-state reaction method. The Y2O2S:Tb3+, Eu3+, Sr2+, Zr4+ phosphors were characterized by X-ray diffraction, photoluminescence, long-lasting phosphorescence and thermoluminescence spectra. The samples doped with different concentration of Eu3+ ions were composed of the pure Y2O2S phase at 1000 °C for 30 min. Under 263 nm UV excitation, the emission peaks at 417 nm and 544 nm were assigned to the 5D3→7F5 and 5D4→7F5 transitions of Tb3+ respectively, and the emission peak at 626 nm was assigned to the 5D0→7F2 transition of Eu3+. With 0.15% Eu3+ concentration, the CIE chromaticity diagram was (0.28, 0.31), the trap depth was 0.89 eV and the decay time could last for over 220 s (≥1 mcd/m2).