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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Gd_2O_2S:Eu~(3+),Si~(4+),Ti~(4+)。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:Gd_2O_2S:Eu~(3+),Si~(4+),Ti~(4+)的晶体结构与Gd_2O_2S相同,为六方晶系。颗粒的形貌为类球形。Gd_2O_2S:Eu~(3+),Si~(4+),Ti~(4+)的激发光谱呈250～400nm宽带状,激发光谱主峰位于365nm;发射光谱为线状光谱,归属于Eu~(3+)的~5D_J(J=0,1)→~7F_J(J=0,1,2,4)跃迁。最强的发射峰为627nm和617nm,均属于~5D_0→~7F_2跃迁,且627nm的发射峰明显远强于617nm,显示出纯正的红色发光;并且Si~(4+)和Ti~(4+)离子的共掺杂可显著延长样品Gd_2O_2S:Eu~(3+)的余辉时间。
A novel red long afterglow luminescent material Gd 2 O 2 S: Eu 3+, Si 4+ and Ti 4+ was synthesized by high temperature solid state reaction. The synthesized products were analyzed and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and spectrophotometer. The results show that the crystal structure of Gd_2O_2S: Eu ~ (3 +), Si ~ (4 +) and Ti ~ (4 +) is the same as Gd_2O_2S and is hexagonal. The morphology of the particles is spherical. The excitation spectra of Gd_2O_2S: Eu ~ (3 +), Si ~ (4 +) and Ti ~ (4 +) showed broad bands of 250 ~ 400 nm and the main peak of the excitation spectrum was at 365 nm. The emission spectrum was linear spectrum and belonged to Eu ~ 3+) ~ 5D_J (J = 0,1) → ~ 7F_J (J = 0,1,2,4) transitions. The strongest emission peaks are 627nm and 617nm, all belong to ~ 5D_0 → ~ 7F_2 transitions, and the emission peak at 627nm is obviously stronger than that at 617nm, showing pure red luminescence; and Si ~ (4+) and Ti ~ (4+ ) Ion co-doping can significantly prolong the decay time of Gd 2 O 2 S: Eu 3+.