CaSiO3∶Pb,Mn荧光粉的ZnO∶Al包覆研究

以Zn(NO3)2•6H2O和AlCl3•6H2O为原料, 借助CO(NH2)2的水解反应, 采用化学均相共沉淀方法和热处理工艺, 在自制CaSiO3∶Pb, Mn红色荧光粉表面包覆ZnO∶Al, 形成透明导电层. 运用数字万用表和自制测量盒对粉体的电阻率进行测量, 比较了包覆率n(Zn)/n(Ca)、n(Al)/n(Zn), 热处理温度和热处理时间对粉体电阻率的影响; 优化出包覆条件和热处理条件: n(Zn)/n(Ca)=10%, n(Al)/n(Zn)=5%, 75 ℃水解1.5 h, 500 ℃热处理45 min. 对包覆样品进行了室温光致荧光(PL)测量, X射线衍射(XRD)结构分析和透射电子显微镜(TEM)形貌观察. 结果显示, 当n(Zn)/n(Ca)=10%时, 在CaSiO3∶Pb, Mn荧光粉表面形成了连续的ZnO∶Al敷膜, 荧光粉的电阻率明显降低, 并且保持了良好的光致发光性质.

A Study of CaSiO3:Pb, Mn Phosphors Coated by ZnO:Al

CaSiO3∶Pb, Mn phosphor particles with red-luminescence were prepared by aqueous co-deposition reaction. Surface modification of CaSiO3∶Pb, Mn phosphors was carried out by coating transparent conductive films of Al-doped zinc oxide which were formed by homogeneous phase co-precipitation and heat treatment process. The coated phosphors were characterized by X-ray diffraction (XRD), photoluminescence (PL), transmittance electron microscopy (TEM) and conductance measurements. The results showed that the conductivity of ZnO∶Al-coated phosphors, n(Zn)/n(Ca)=10%, n(Al)/n(Zn)=5%, had been improved obviously while the corresponding photoluminescence intensity remained the same as the as-prepared phosphors. For lowering the resistivity of phosphors, experimental conditions have been optimized, which include hydrolyzing at 75 ℃ for 1.5 h, heat treatment at 500 ℃ for 45 min, respectively.