分步滴定法制备YAG荧光粉及性能研究

发布时间：2018-05-18 09:49

本文选题：铈掺杂YAG荧光粉 + 分步滴定法　；参考：《河南理工大学》2011年硕士论文

【摘要】：荧光粉经过紫外/蓝光发光二极管辐射转换为发白光，业已证明LED加荧光粉是非常有前景的固体发光技术，也是未来极其重要的节能照明光源。白光发光二级管有节能、寿命长、无汞的优点。当前的商业白光发光二极管显示器是用涂覆YAG:Ce荧光粉制成的，由于4f1-5d1的电子跃迁，在YAG中的铈离子能有效地吸收450nm到470nm的蓝光并能发射510nm到超过600nm范围的发光宽带，这些光谱的性质使YAG:Ce成为通过蓝光辐射LED转变为白光的很好的荧光粉。本论文的主要工作是以分步滴定法制备YAG：Ce荧光粉为研究目标，优化最佳工艺参数，并以此为基础通过多元离子掺杂来实现白光LED不同色温的调控。研究的主要内容和结论如下： (1)采用分步滴定法制备YAG:Ce黄色荧光粉，讨论了沉淀剂、溶剂、分散剂、pH值、Ce掺杂浓度、煅烧温度、煅烧时间、气氛、助熔剂等对荧光粉各种性能的影响。 (2)采用多元离子共激活，对Gd~(3+)、Ga~(3+)、Pr~(3+)等取代YAG:Ce中的基质元素进行研究，结果表明，掺杂的稀土离子取代了YAG中部分Y3+或A1~(3+)，可以实现发射光谱峰值波长发生红移或蓝移。 (3)由于在煅烧过程中加入助熔剂，导致生成的荧光粉中有杂质出现，通过酸洗、干燥、研磨，提高了荧光粉的发光性能。 (4)通过对自制荧光粉和英特美荧光粉进行封装比较，找出与美国荧光粉进行各性能的差距，为以后工作提供指导。主要创新点：（1）采用分步滴定法工艺方法制备YAG荧光粉，在发光性能方面有很大的提高，与市面荧光粉发光性能相比较，其相对发光效率达到160%，已经基本达到实用需求。（2）通过对采用多元离子（Gd、La、Ga）共掺杂YAG:Ce荧光粉进行深入研究，获得了调控荧光粉峰值波长的工艺方法，显著的改善了荧光粉显色性色差、红光成分不足等问题。（3）通过对荧光粉进行酸、碱清洗、研磨、分筛处理，进一步改善了荧光粉的发光性能，，提高了荧光粉的稳定性、可靠性及应用性。
[Abstract]:Phosphors are converted into white light by ultraviolet / blue light emitting diodes. It has been proved that LED plus phosphor is a very promising solid-state luminescence technology, and it is also an important energy-saving lighting source in the future. White light emitting secondary tube has the advantages of energy saving, long life and no mercury. The current commercial white light-emitting diode displays are made from coated YAG:Ce phosphors. Because of the electronic transition of 4f1-5d1, cerium ions in YAG can effectively absorb the blue light from 450nm to 470nm and emit 510nm to luminescent broadband beyond 600nm. The properties of these spectra make YAG:Ce a good phosphor for the conversion of blue LED to white light. The main work of this thesis is to optimize the optimum technological parameters of preparing YAG:Ce phosphors by stepwise titration, and to realize the control of different color temperature of white LED by multi-ion doping. The main contents and conclusions of the study are as follows: YAG:Ce yellow phosphors were prepared by stepwise titration. The effects of precipitant, solvent and dispersant pH value ce doping concentration, calcination temperature, calcination time, atmosphere and flux on the properties of phosphors were discussed. In this paper, the matrix elements in the substitution of YAG:Ce by Gd~(3 (Gd~(3) are studied by multicomponent ion co-activation. The results show that the doped rare earth ions can replace some of the Y _ 3 or A _ (1) O _ (3) in YAG, and the peak wavelength of the emission spectrum can be shifted red or blue. 3) due to the addition of flux in the calcination process, impurities appear in the phosphors produced, and the luminous properties of the phosphors are improved by acid washing, drying and grinding. 4) by comparing the self-made phosphors with the British phosphors, we can find out the difference between the self-made phosphors and the American phosphors and provide guidance for the future work. Major innovations: 1) the luminescent properties of YAG phosphors prepared by stepwise titration method have been greatly improved. Compared with the luminescent properties of phosphors in the market, the relative luminescence efficiency of the phosphors has reached 160%, which has basically reached the practical demand. 2) based on the in-depth study of co-doped YAG:Ce phosphors with multicomponent ions, the process of controlling the peak wavelength of phosphors has been obtained, which has improved the chrominance difference of phosphors and the shortage of red components, and so on. 3) through acid, alkali cleaning, grinding and screening treatment, the luminescent properties of phosphors are further improved, and the stability, reliability and application of phosphors are improved.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：O482.31

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