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摘要采用高温固相法合成了LiNbO3:xEu3+ (x= 0.01, 0.003,0.005,0.001)发光材料。使用X射线粉末衍射和SEM研究了Eu掺杂LiNbO3的相干性和粉体的粒径大小及形貌特征，并用荧光光谱仪分析了不同浓度Eu掺杂LiNbO3的发光性能。结果表明，最佳的烧结温度是1150℃。通过发射光谱可以发现，随着Eu3+摩尔分数的增大，发射强度先减小后增大。当Eu3+的摩尔分数为1%时，样品的发光强度最大。对于发光性质结果如下：LiNbO3：Eu3+荧光粉的激发光谱为单峰宽带结构，峰值位于297nm处，对应于Eu3+-O2-的之间的电荷转移。LiNbO3：Eu3+样品的发射光谱有五个较强的发射峰，其中5D0→7F2 (625nm)的跃迁发射最强。另外，Eu3+浓度对样品荧光寿命影响较弱，Eu3+浓度为1%时荧光寿命为573.0nm。通过LiNbO3：Eu3+荧光粉发光性能的分析，我们观察到了该荧光粉在625nm处有较强的红光发射，有望成为红光LED发光材料。24194
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毕业论文关键词： LiNbO3:Eu3+；白光LED；发光材料；高温固相法
Abstract：
This paper, high-temperature solid-phase synthesis of LiNbO3: xEu3+ (x = 0.01, 0.003,0.005,0.001) luminescent material. Eu-doped LiNbO3 coherence and powder particle size and morphology was studied by using XRD and SEM, and luminescent properties of LiNbO3 doped with different concentrations of Eu was analyzed by fluorescence spectroscopy. The optimum sintering temperature is 1150 ℃.It could be found by the emission spectrum that as the mole fraction of Eu3+ is increased, the emission intensity of the first decreases and then increases. When Eu3+ mole fraction is 1%, the luminous intensity of the sample is maximum. For the luminescence properties were as follows: LiNbO3: Eu3+ phosphor excitation spectrum is broadband single peak structure, the peak is located at 297nm, correspond to the electric charge transfer of Eu3+-O2-. LiNbO3: Eu3+ emission spectra of the sample have five strong emission peaks, 5D0 → 7F2 (625nm) transitions emission is strongest. In addition, Eu3+ concentration on the sample fluorescence lifetime is weak, the fluorescence lifetime is 573.0nm when the concentration of Eu3+ was 1%.By the analysis of LiNbO3: Eu3+ phosphor luminescence. We observed at 625nm of the phosphors have a strong red emission ,it is expected to become a red LED luminescent material.
Keywords: LiNbO3:Eu3+；White LED；luminescent materials；high temperature solid state synthesis
目录
１ 绪论 1
1.1 LED产业 1
1.1.1 LED发光的实现途径 1
1.1.3国内外LED研究现状及发展前景 2
1.2 稀土元素铕 3
1.2.1 元素简介 3
1.2.2 基本性质 3
1.2.3 主要用途 3
1.3 铌酸锂（LiNbO3）材料 4
1.3.1 LiNbO3晶体的结构 4
1.3.2 LiNbO3晶体的生长 4
1.3.3 LiNbO3晶体的应用 4
2 实验部分 6
2.1 实验主要原料 6
2.2 实验主要仪器设备 6
2.3 制备方法选择 7
2.4 试样制备工序 7
2.5 工艺优化 8
2.5.1 研磨顺序影响 8
2.5.2 烧结温度影响 8
2.5.3 Eu3+掺杂浓度影响 8
2.6 测试与表征 9
3 结果与讨论 10
3.1 XRD图谱分析 10
3.2 LN形貌分析 11
3.3 激发-发射光谱分析 11
4 结论 18
5 致谢 19
6 参考文献 20
１ 绪论
1.1 LED产业
1.1.1 LED发光的实现途径
LED通过多种方式可以获得白光，在LED芯片上涂荧光粉产生白光这种方法开发较早，而且实现产业化。LED实现白光主要方法有三种，但这些方法并不成熟，因而影响白光LED应用于照明领域。