Eu^(3+)离子激活荧光粉Ca_(1.9)Eu_(0.1)NaMg_(2-x)Zn_x(VO_4)_3(0≤x≤1)的发光性质

Photoluminescence Properties of Eu^(3+)-activated Ca_(1.9)Eu_(0.1)NaMg_(2-x)Zn_x(VO_4)_3(0≤x≤1.0) Phosphor

采用固相反应法合成了Eu^(3+)离子激活的Ca_(1.9)Eu_(0.1)NaMg_(2-x)Zn_x(VO_4)_3(0≤x≤1),并研究了其发光和热猝灭性能。经粉末X射线衍射确认,反应产物由目标相和微量杂质相EuVO_4构成。在355 nm激发下,样品中均能同时观察到来自[VO_4]_3-基团和Eu^(3+)离子的特征发光。研究结果表明:随着x值的增加,上述两种发光的强度均先增加后降低;而它们的最强激发峰位置由347 nm逐渐地红移至356 nm,Stokes位移也逐渐地减小。这种现象应归因于Zn3d轨道和O2p轨道间很强的轨道杂化效应,这种效应随着x值的增加而逐渐增强。此外,Eu^(3+)离子荧光发射强度最大值对应的x值与自激活荧光的不同。当x=1.0时,两者的相对强度差别最大。经荧光热猝灭测试确认,上述现象是由样品中的自激活荧光表现出比Eu^(3+)离子荧光更严重的荧光热猝灭造成的。因而,在紫外光激发下,样品发出荧光的颜色具有温度敏感性。

Eu3＋-activated Ca1.9Eu0.1NaMg2-xZnx（VO4）3 （0≤x≤1） were synthesized by solid-state reaction route, and their photoluminescence and thermal quenching properties were studied.The samples were verified through powder X-ray diffraction, and the target phase was identified with tiny impurity of EuVO4 in the obtained product.Excited by 355 nm, all the samples show the characteristic emissions from [VO4]3-group and Eu3＋ ion.With the increment of x value, the intensity of either of the above mentioned emissions increases at first and then decreases, while a red-shifting excitation peak from 347 nm to 356 nm and a decreasing Stokes-shift can be observed.Stronger hybridization effect occurres between the Zn3d orbital and the O2p orbital resulted by the increasing x value which is supposed to be responsible for that phenomena.Furthermore, the x value corresponding to the observed intensity maximum for Eu3＋ emission is different from the one for self-activated emission.Their highest difference is observed in the sample of x=1.0.It could be due to an apparently more serious thermal quenching of self-activated emission than that of Eu3＋ ion emission.Then, a temperature-sensitive color of the emission is also observed in the samples excited by the near ultraviolet light.