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。
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.