采用溶胶凝胶法制得高纯的B2OrCaO∶Eu3+荧光粉.用XRD、IR对不同退火温度下所得样品的结构进行表征,结果发现随退火温度的变化,能形成不同结构的硼酸盐基质.通过对以不同结构硼酸盐为基质荧光粉的激发、发射谱图及荧光衰减曲线的分析,探讨了材料的发光性能和发光机理.结果表明,在不同结构硼酸盐基质中,Eu3+都处于无反演对称中心格位,以(5Do→7F2电偶极跃迁为主,所以材料主要发红光;且900℃退火所得高纯相的CaB2O4基质最有利于发光、对应的荧光衰减时间最长,这都因在此荧光粉中Eu3+更易取代Ca2+,并形成相对较多的p-n结和陷阱所致.%The high pure B2O3-CaO∶Eu3+ phosphor is prepared by sol-gel method.The structures of samples obtained at different annealing temperatures are characterized by XRD and IR.It is found that the borate matrix with different structures can be formed with the change of annealing temperature.Based on the analysis of the excitation spectrum,emission spectrum and fluorescence decay curves of borate phosphors with different structures,the luminescent properties and luminescent mechanism of the phosphors are investigated.The result indicate that Eu3+ ions occupy no inversion symmetry site with the dominant electric dipole transition in borate matrix of the different structure,and these phosphors give off red light under ultraviolet excitation.The high pure CaB2O4 matrix obtained by annealing at 900 ℃ is most favorable for luminescence and the B2O3-CaO ∶Eu3 + phosphor have the longest fluorescence decay time.These are attributed to the fact that Eu3+ in the matrix is more likely to replace Ca2+ to form relatively large numbers of p-n junctions and traps.
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