SrAl_2O_4∶Eu^(2+),Dy^(3+)晶格点缺陷的形成及其在发光材料中的作用

Formation and Roles of Point Defects in SrAl_2O_4∶Eu^(2+),Dy^(3+) Phosphors

采用高温固相法合成了具有不同点缺陷的SrAl2O4∶Eu2+,Dy3+发光粉。通过余辉衰减特性、激发光谱与热致发光性能测试,研究了晶格点缺陷在发光材料中的作用。结果表明,DyS·r对长余辉发光性能有很大的影响,可以作为具有合适深度的电子陷阱;氧离子空位(VO··)不能作为具有合适深度的电子陷阱,但可增加电子陷阱Dy3+的深度;掺入晶格的Dy3+与Eu2+之间存在相互作用,而且只有当DyS·r与EuSr×之间的距离足够接近时,DyS·r才能起到有效的电子陷阱的作用;VSr″可作为空穴陷阱,但VSr″浓度的变化不会引起长余辉发光性能的明显变化。

The SrAl2O4：Eu^2＋,Dy^3＋ phosphors containing different point defects were synthesized by solid-state reaction method. The roles of crystal point defects in SrAl2O4：Eu^2＋,Dy^3＋ phosphors were studied by comparing afterglow decay properties, excitation spectra and thermoluminescence of different samples. The results show that DySr^· plays an important role in persistent luminescence of SrAl2O4：Eu^2＋,Dy^3＋ phosphors. It can serve as an effective electron trap having apprepriate depth for persistent luminescence. Vo^·· can not serve as the electron trap with an appropriate depth, but can increase the trap depth of the DySr^· There is interaction between the Dy^3＋（DySr^·） and the Eu^2＋（EuSr^x）, and only if the distance between them is close enough, can DySr^· become effective electron trap. The VSr＂ can become hole trap, but the change of its concentration in phosphors does not arouse the obvious change of persistent luminescence.