新型红色长余辉发光材料Gd2O2S:EU3+,Si4+,Ti4+的合成及性能表征

采用高温固相反应法首次合成了新型红色长余辉发光材料Gd2O2S:Eu3+,Si4+,Ti4+.用X射线粉末衍射(XRD)、扫描电镜(SEM)、分光光度计等对合成产物进行了分析与表征.结果表明:Gd2O2S:Eu3+,Si4+,Ti4+的晶体结构与Gd2O2S相同,为六方晶系.颗粒的形貌为类球形.Gd2O2S:Eu3+,Si4+,Ti4+的激发光谱呈250～400 nm宽带状,激发光谱主峰位于365 nm;发射光谱为线状光谱,归属于Eu3+的5DJ(J=0,1)→7FJ(K=0,1,2,4)跃迁.最强的发射峰为627 nm和617 nm,均属于5D0→7F2跃迁,且627 nm的发射峰明显远强于617nm,显示出纯正的红色发光;并且Si4+和Ti4+离子的共掺杂可显著延长样品Cd2O2S:Eu3+的余辉时间.

Synthesis and Characterization of the Red Long Afterglow Phosphor Gd2 O2 S:Eu3+, Si4+,Ti4+

Gd2O2S:Eu3+,Si4+ ,Ti4+ , as a novel red long afterglow phosphor, was first synthesized by high-temperature solid-state reac-tion method. The synthesized phosphors were investigated respectively by XRD, SEM and fluorescence speetrophotometer. The results showed that: Gd2 O2 S: Eu;3+, Si4+ , Ti4+ possess hexagonal crystal structure, which is similar to that of Gd202 S matrix. The particles of Gd2O2S: Eu3+, Si4+, Ti4+are basically spherical in shape,with good dispersion. The excitation spectrum is a broad band, from 250 nm to 400 nm, and the main peak is at 365 nm. The emission spectrum shows that Gd2O2S:Eu3+, Si4+, Ti4+has narrow emissionpeaks which belong to Eu3+ ions transition from 5DJ(J=0,1,2) to 7FJ(J= 0,1,2,3,4). The strongest emission peak is at 627nm and 617 nm, which belongs to the Eu3+ ions transition from 5D0→7F2. Moreover, the relative intensity of the emission peak (λ =627nm)is markedly stronger than that of the emission peak (λ=617 nm). Therefore, Gd2O2S:Eu3+ , Si4+, Ti4+emits the pure red light. What's more, the afterglow time of Gd2O2S:Eu3+ can be significantly increased when the Si4+ and Ti4+ are co-doped.