三价钆、三价锑共掺杂钙钛矿荧光粉的改性制备

Preparation of Trivalent Gadolinium and Trivalent Stibium Codoped Perovskite Phosphor

采用改进固相法与传统固相法合成了钙钛矿(YAl O3:Gd^(3+)/Sb^(3+))荧光粉体,借助XRD,SEM,分子荧光光谱等手段研究了两种方法制备的GdAl O_3:Er^(3+),Yb^(3+)荧光粉结构形貌与发光性能。结果表明:在相同焙烧温度下,使用改进固相法能够得到分散均匀的,颗粒大小一致的荧光粉,而传统固相法存在一定的颗粒团聚现象。在254 nm波长激发下,改进固相法与传统固相法合成的三价钆、三价锑共掺杂钙钛矿荧光粉体系均得到425 nm左右(紫光)宽带发射光谱,归属于Sb^(3+)的~3P_1→~1S_0跃迁;发光强度随Gd^(3+)与Sb^(3+)的掺杂浓度增加先升高后降低,且改进方法所得荧光粉的发光强度一直保持高于传统固相法所得荧光粉发光强度,最高达2.09倍。最后,通过对基质晶格结构与发光离子能量传递距离对三价钆、三价锑共掺杂钙钛矿荧光粉发光机理进行可能性分析。

The perovskite phosphors YAlO3：Gd（3＋）/Sb（3＋） were respectively synthesized by modified solid-state method and conventional high-temperature solid-state method. The effect of the preparation methods on the structures, morphologies and photoluminescence of the phosphors was investigated by using XRD, SEM and fluorescence spectrometer. The result showed that the particles of phosphors prepared by modified solid phase method exhibited uniform particle size, while the particles of phosphors prepared by conventional high-temperature solid-state method showed a certain particle aggregation phenomenon under the same calcination temperature. Under 254 nm excitation, the co-doped phosphors YAlO3：Gd（3＋）/Sb（3＋） prepared by modified solid-state reaction and conventional high-temperature solid-state method both showed wide emission at a wavelength of 425 nm（purple light）, which was assigned to the 3P1→1S0 transition of the Sb（3＋） ion. The luminescence intensity increased first and then decreased with increasing of doping concentrations of Gd（3＋） and Sb（3＋） ions. Meanwhile the luminescence intensity of the phosphors obtained by modified solid-state method was obviously higher than that of the phosphors obtained by the conventional solid-state method, and the maximum difference was 2.09 times. In the end, the possible luminescence mechanism was explained through the analysis of host lattice structure and energy transfer distance.