CaSnO3∶Tb3+绿色长余辉荧光粉的制备与发光性质的研究

采用高温固相法合成了CaSnO3∶Tb3+绿色长余辉荧光粉。利用X射线衍射分析了CaSnO3∶Tb3+物相结构。研究了Tb3+浓度对样品发光强度的影响,结果显示:随Tb3+浓度的增大,发射光谱强度先增大后减小,出现了浓度猝灭效应,Tb3+的最佳摩尔分数为0.3%。发射光谱由4个主要发射峰组成,峰中心分别位于492,546,588,623 nm处,以Tb3+的5D4→7F5(546 nm)跃迁发射为最强。对样品的温度特性进行了测量,通过对数据进行拟合得到样品的激活能为0.58 eV,陷阱深度为0.622 eV。最后,给出了CaSnO3∶Tb3+绿色长余辉荧光粉可能的余辉发光机理。

Preparation and Luminescent Properties of Green Long Lasting CaSnO3∶Tb3+ Phosphor

Green long lasting phosphors of CaSnO3∶Tb3+have been successfully synthesized by solid-state reaction. The crystal structures of CaSnO3∶Tb3+samples were analyzed by means of X-ray powder diffraction (XRD). The influence of Tb3+ concentrations on the luminescent intensities was investigated. The results show that the intensities of the phosphors increase, and then decrease with the Tb3+ions concentration, which means there exist concentration quenching. The optimized mole fraction of Tb3+ is 0.3%. The emission spectra display four main emission peaks, locating at 492, 546, 588 and 623 nm, respectively. The intensity of the emission peak originating from 5D4→7F5 transition is the strongest. By measuring the temperature character of the phosphors, the activation energy for thermal quenching process is 0.58 eV and the depth of trap is calculated to be 0.622 eV. Moreover, the possible mechanism of the green long lasting phosphorescence is proposed based on the experiment results.