Eu^(3+)掺杂的Na_2YMg_2(VO_4)_3荧光粉制备和发光特性

Synthesis and Luminescent Properties of Eu^(3+) Doped Na_2YMg_2(VO_4)_3 Phosphors

采用溶胶-凝胶法制备了Na2Y1-xMg2(VO4)3∶x Eu^(3+)(x=0.15~0.75)系列自激活荧光粉。用XRD、SEM、光致发光光谱和荧光衰减曲线分别对其结构、形貌和发光性能进行表征。XRD结果显示样品为纯石榴石结构,其中Eu^(3+)取代Y^(3+);SEM照片显示样品为粒径大小在0.3~1μm范围内不规则的光滑球状颗粒;光谱分析表明,Na2YMg2(VO4)3作为自激活发光基质可以被200~400 nm紫外光有效激发,发出源于VO_4^(3-)电荷迁移跃迁的波长范围为400~700 nm的宽谱带绿光。掺杂Eu^(3+)后,在340 nm紫外光激发下同时出现了VO_4^(3-)的电荷迁移带和Eu^(3+)的特征光谱。不同浓度Eu^(3+)掺杂的光谱和荧光衰减曲线表明,存在VO_4^(3-)和Eu^(3+)之间的能量传递。

A series of self-activated vanadate phosphors Na2Y1-xMg2 （VO4）3： xEu^3＋ （x= 0.15 - 0.75） were prepared by sol-gel method. The phase formation, surface morphology and luminescence properties of the samples were verified by XRD, SEM, photoluminescence spectra and decay curves. It is found that the obtained samples are pure crystalline phases with garnet structure. The particles with a diameter ranging from 0.3 to 1 p,m show irregular shapes and have a tendency to be agglomerating. This host can be excited by ultraviolet （UV） light, and it exhibits a broad-band green emission in the region from 400 to 700 nm, ascribing to the charge transfer of VO34- groups. Na2YMg2 （VO4） 3：Eu^3＋ phosphors show both characteristic broad-band emission from VO4^3- groups and sharp emissions from Eu^3＋ ions upon 340 nm UV light. Moreover, the intensities of host and Eu^3＋ emission depend on the doping concentration of Eu^3＋ The energy transfer from VO4^3- to Eu^3＋ was discussed based on spectrum analysis and decay curves.