Y_2Ti_2O_7∶Tm^(3+)的制备及其发光性能研究

Synthesis and Luminescence Properties of Y_2Ti_2O_7∶Tm^(3+) Phosphor

采用溶胶-凝胶法(Sol-gel)制备了不同烧结温度和Tm3+掺杂浓度的Y2Ti2O7∶x Tm(x=0.005,0.01,0.03,0.05)荧光粉,分别采用X射线衍射分析仪(XRD)、透射电子显微镜(TEM)和荧光光谱仪对样品的晶型结构、形貌以及发光性能进行了表征。XRD结果表明,所得到的样品为单一立方相烧绿石结构。样品在361nm紫外光激发下发射出蓝光,其峰值波长为456 nm,对应于Tm3+的1D2→3F4跃迁。1 000℃烧结的Y2Ti2O7∶0.01Tm3+样品具有较好的发光性能。样品在456 nm处的相对发光强度随Tm3+掺杂浓度的增大先升高后降低,在Tm3+摩尔分数为1%时达到最大,即出现了浓度猝灭现象。

Y2Ti2O7∶xTm（x=0. 005, 0. 01, 0. 03, 0. 05） phosphors were prepared by solgel method and sintered at different temperatures. The structure, morphologies, and luminescence properties of samples were characterized by X-ray diffraction （XRD）, TEM, and fluorescence spectrophotometer, respectively. The XRD patterns indicate that the structure of samples belongs to pyrochlore structure, and is not changed by the doping of Tm^3＋. Blue emissions centered at 456 nm, corresponding to 1 D2→3 F4 transition of Tm^3＋, are detected under 361 nm excitation. The best luminescence performance is derived when the sintering temperature is 1000 ℃ for Y2Ti2O7∶0. 01Tm^3＋. Furthermore, the emis-sion intensity at 456 nm increases and then decreases with the increasing of Tm^3＋ concentration. The most intense emission is obtained when the mole fraction of Tm3＋ is 1%, which indicates that the concentration quenching happens when the mole fraction of Tm^3＋ exceeds 1%.