新型红色长余辉发光材料Gd_2O_2S:Eu^(3+),Si^(4+),Ti^(4+)的合成及性能表征(英文)

Synthesis and Characterization of the Red Long Afterglow Phosphor Gd_2O_2 S:Eu^(3+),Si^(4+),Ti^(4+)

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。

Gd_2O_2S:Eu^(3+),Si^(4+),Ti^(4+),as a novel red long afterglow phosphor,was first synthesized by high-temperature solid-state reaction method.The synthesized phosphors were investigated respectively by XRD,SEM and fluorescence spectrophotometer.The results showed that:Gd_2O_2S:Eu^(3+),Si^(4+),Ti^(4+) possess hexagonal crystal structure,which is similar to that of Gd_2O_2S matrix.The particles of Gd_2O_2S:Eu^(3+),Si^(4+),Ti^(4+) 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 Gd_2O_2S:Eu^(3+),Si^(4+),Ti^(4+) has narrow emission peaks which belong to Eu^(3+) ions transition from ~5D_J(J=0,1,2) to ~7F_J(7=0,1,2,3,4).The strongest emission peak is at 627nm and 617 nm,which belongs to the Eu^(3+) ions transition from ~5D_0→~7F_2.Moreover,the relative intensity of the emission peak(λ=627 nm)is markedly stronger than that of the emission peak(λ=617 nm).Therefore,Gd_2O_2S:Eu^(3+),Si^(4+),Ti^(4+) emits the pure red light.What's more,the afterglow time of Gd_2O_2S:Eu^(3+) can be significantly increased when the Si^(4+) and Ti^(4+) are co-doped.