采用溶剂热法合成了α-NaYF4∶5%Eu3+红色荧光粉, 研究不同退火温度对荧光粉晶体结构、形貌、发光以及显色性能 (CIE)的影响。通过比较退火前后以及不同退火温度下荧光粉的发光性能, 发现退火使得禁戒跃迁5D0→7F0发生, 随着退火温度的升高, Eu3+所有发射峰都得到了相应的增强, 并且相应的CIE更趋向于红色; 但在高温退火时, 纳米晶之间的团聚更加严重, 而且CIE趋向于红色的速度变慢。基于非对称性比率σ的分析, 认为本文中5D0→7F0跃迁是由于Eu3+占据非对称中心格位所致。

α-NaYF4∶5%Eu3+ red phosphors were prepared by the solvothermal method. The crystal structure, morphology, luminescence properties and the chromaticity coordinates(CIE) were discussed under different annealing temperature, and three samples of them were coated with SiO2 before annealed in air. It is found that the forbidden 5D0→7F0 transition emerges after annealing treatment, and all the characteristic emission peaks of Eu3+ are enhanced with the increasing of annealing temperature, correspondingly the CIE turns to red. But the nanoparticles reunite each other under high annealing temperature, and the tendency of CIE turning to red is slower. Based on the results of asymmetric ratio σ, we consider the appearance of 5D0→7F0 transition is from Eu3+ deviating from the inversion symmetry center.