新型长余辉发光材料的研究
关键词： ZnGa204 ；激发发射光谱；衰减；热释光谱The research of new long afterglow luminescent materials
Abstract：Red long lasting phosphors of ZnGa204 :Cr3+ added lanthanide ions(Dy3+,Sm3+) have been successfully synthesized by solid-state reaction. The crystal structures and intensities of the phosphors of ZnGa204:Cr3+ samples were analyzed by means of X-ray powder diffraction (XRD) and fluorescence spectrometer. The sintering temperature and the influence of Cr3+ concentrations on the luminescent intensities were investigated．The results show that the best sintering temperature is 1200 ℃ ,the intensities of the phosphors increase, and then decrease with the Cr3+ ions concentration, which means there exist concentration quenching. The optimized mole fraction of Cr3+ is 1% . Then the afterglow properties of ZnGa204:Cr3+ are studied by Thermoluminescence measurement instrument. Through the afterglow decay curves we can draw the afterglow time is 106.2s, and through the thermoluminescence spectrum we conclude that the trap depth is 0.366eV. And the effect of co-doped lanthanide ions (Sm3+,Dy3+ )on the luminescent performance of the afterglow decay curve is researched, we can draw the afterglow time are 87.6 and 104.3s respectively, and the trap depths can be obtained in the thermoluminescence spectra are respectively 0.432,0.567eV. Moreover, the mechanism of the red long lasting phosphorescence is proposed based on the experiment results.
Key Words: ZnGa204 ; excitation-emission spectroscopy; decay; TL spectra
目录
1 绪论 5
1.1 长余辉发光材料研究的意义和进展 5
1.2 镓酸锌体系的简介 5
1.3 ZnGa2O4:Cr3+ 发光材料的制备方法 6
1.3.1 高温固相法 6
1.3.2 溶胶-凝胶法 6
1.4 长余辉发光材料的发光和余辉机理 7
1.5 影响余辉时间长短的因素 7
1.6 主要影响因素——陷阱深度的测量方法 8
2 实验 11
2.1 实验原材料和药品 11
2.2 实验用仪器设备 11
2.3 制备方法的选择 12
2.4 试样制备 12
2.5 工艺优化 13
2.5.1 烧结温度的影响 13
2.5.2 Cr3+掺杂比例的影响 13
2.5.3 共掺杂稀土元素离子的影响 13
2.6 测试与表征 14
3 结果与讨论 15
3.1 烧结温度的影响 15
3.2 Cr3+掺杂比例的影响 17
3.2.1 对物相的影响 17
3.2.2 对发光性能的影响 17
3.3 余辉性质 20
3.3.1 Cr3+摩尔分数为1%时的余辉性质 20
3.3.2 共掺杂稀土元素离子的样品的余辉性能 22