掺杂离子对白色长余辉发光材料Y2O2S:Tb3+, Eu3+,M2+ (M=Mg,Ca, Sr,Ba),Zr4+性能的影响

采用高温固相法制备了白色长余辉发光材料Y₂O₂S:Tb³⁺, Eu³⁺,M²⁺(M=Mg, Ca, Sr, Ba), Zr⁴⁺, 利用X晶体衍射、发光光谱、余辉曲线和热释光曲线等对制备的材料进行表征。结果表明:掺杂离子没有改变样品晶体结构和发射峰的位置,但对其发光强度、余辉时间及陷阱深度有较大的影响。在263 nm紫外光的激发下,469 nm和626 nm的发射分别对应于Eu³⁺的⁵D₂→⁷F₀、⁵D₀→⁷F₂跃迁,544 nm的发射对应于Tb³⁺的⁵D₄→⁷F₅跃迁,主要通过它们的混合产生白光。掺杂不同二价离子样品的余辉性能按Mg²⁺、Sr²⁺、Ca²⁺、Ba²⁺的顺序递减,其中掺杂Mg²⁺的样品,色度坐标为(0.29,0.32),陷阱深度为1.17 eV,余辉时间长达320 s(≥1 mcd/m²),表现出最佳的发光性能。

Effect of Doping Ions on Properties of The White-light Long-lasting Phosphor Y2O2S:Tb3+, Eu3+, M2+(M=Mg,Ca, Sr,Ba), Zr4+

Y₂O₂S:Tb³⁺, Eu³⁺,M²⁺(M=Mg, Ca, Sr, Ba), Zr⁴⁺ white-light long-lasting phosphors were synthesized by the solid-state reaction method. The phosphors were characterized by X-ray diffraction, photoluminescence spectra, long-lasting phosphorescence and thermoluminescence curves. The results show that the doping ions do not change the crystal structure and the situation of emission peaks of phosphors, but influence the intensity, afterglow time and trap depth. Under 263 nm UV excitation, the emission peaks at 469 nm and 626 nm are assigned to the ⁵D₂→⁷F₀ and ⁵D₀→⁷F₂ transitions of Eu³⁺ respectively, and the peak at 544 nm is assigned to the ⁵D₄→⁷F₅ transition of Tb³⁺. The white-light can be obtained by the appropriate mixing of them. The afterglow properties of the phosphors doped with different divalent ions decreases according to the order of Mg²⁺,Sr²⁺, Ca²⁺, Ba²⁺. With Mg²⁺, the CIE chromaticity diagram was (0.29, 0.32), the trap depth was 1.17 eV and the decay time could last for over 320 s (≥1 mcd/m²). Therefore, the sample doped Mg²⁺ ion shows the optimal luminescent properties.