白光LED用YAG荧光粉制备工艺研究

发布时间：2018-04-20 18:49

本文选题：白光LED + 荧光粉　；参考：《电子科技大学》2015年硕士论文

【摘要】：为控制全球温室气体排放,节约消耗能源,近年来各国制定能源政策的同时,竞相提出“节能减碳”计划,其中澳洲、欧盟以及美国加州等已陆续宣布淘汰白炽灯作为照明设施。随着半导体发光技术的发展,LED以其高效、节能、环保等显著优点,在照明、显示等领域得到了广泛应用,对节能减排具有重要的意义。实现白光LED的途径有多种,就技术水平和制造成本而言,目前使用最为普遍最成熟的一种是蓝光LED芯片覆盖一层掺铈钇铝石榴石黄色荧光粉(YAG:Ce),使蓝光和黄光混合得到白光。荧光粉是实现白光LED的关键环节之一,荧光粉作为半导体照明技术中的关键材料之一,它的品质直接影响着白光LED的发光亮度、光效、显色指数、色温、光衰及寿命等性能。目前白光LED用掺铈钇铝石榴石黄色荧光粉(YAG:Ce)的制备方法主要有高温固相烧结法、液相化学共沉淀法、水热法、溶胶凝胶法、Pechini胶体法、微乳液法、燃烧法、微波法等。本论文综述了几种制备方法,总结了它们的优缺点,并重点对液相沉淀法进行了研究。研究了液相沉淀法中各个工艺条件对荧光粉性能的影响,探讨了稀土掺杂对荧光粉结构和发光性能的影响,并对荧光粉体进行了包覆处理实验。主要研究内容如下:(1)综述白光LED用荧光粉的种类、制备方法,分析各种类和方法的优缺点;(2)液相共沉淀法制备合格的前驱体,包括原材料的选定、沉淀剂和表面活性剂的选择、溶液浓度的标定、沉淀和陈化的条件等;(3)一次煅烧:煅烧温度的选择、煅烧时间的选择、助熔剂的选择、最佳铈掺杂浓度;(4)二次还原:利用氢气的还原性将晶体中的Ce4+离子还原为Ce3+,目的是提高荧光粉的发光效率;(5)包覆处理:在荧光粉颗粒表面形成一层二氧化硅包覆层,从而提高成品的发光性能和使用寿命;(6)封装实验:用实验制备的YAG:Ce荧光粉与蓝光LED芯片配合封装出1W的白光LED器件,并组装成LED球泡灯,以综合检测荧光粉的性能指标。上述研究用液相沉淀法制备了YAG:Ce荧光粉,作了有意义的研究和实验,为进一步的研究提供了理论依据。
[Abstract]:In order to control global greenhouse gas emissions and save energy consumption, in recent years, when countries have formulated energy policies, they have been competing to put forward plans to "save energy and reduce carbon", among which Australia, The European Union and California have announced that incandescent lamps have been phased out as lighting facilities. With the development of semiconductor light-emitting technology, LED has been widely used in lighting, display and other fields with its advantages of high efficiency, energy saving, environmental protection and so on, which is of great significance to energy saving and emission reduction. There are many ways to realize white LED. At present, one of the most widely used LED chips is the blue LED chip with a layer of yttrium aluminum garnet yellow phosphor, which makes the mixture of blue light and yellow light get white light. Phosphor is one of the key links in the realization of white LED. As one of the key materials in semiconductor lighting technology, the quality of phosphor directly affects the luminance, luminous effect, color index, color temperature, light decay and lifetime of white LED. At present, the preparation methods of yttrium aluminum garnet yellow phosphor with cerium doped yttrium aluminum garnet for white LED are high temperature solid state sintering, liquid phase chemical coprecipitation, hydrothermal method, sol-gel method, microemulsion method, combustion method, microwave method and so on. In this paper, several preparation methods are reviewed, their advantages and disadvantages are summarized, and the liquid precipitation method is studied. The effects of different processing conditions on the phosphor properties were studied. The effects of rare earth doping on the phosphor structure and luminescence properties were discussed. The coating experiments were carried out on the phosphors. The main research contents are as follows: (1) A review of the types and preparation methods of phosphors for white LED, and analysis of the advantages and disadvantages of various types and methods) the preparation of qualified precursors by liquid phase coprecipitation, including the selection of raw materials, the selection of precipitators and surfactants, Determination of solution concentration, conditions of precipitation and aging, etc.) single calcinations: selection of calcination temperature, selection of calcination time, selection of flux, The optimum concentration of cerium doped is 4) secondary reduction: the Ce4 ion in the crystal is reduced to Ce3 by hydrogen reduction, the aim is to improve the luminescence efficiency of the phosphor and the coating treatment: to form a layer of silica coating on the surface of the phosphor particle, so as to improve the luminescence efficiency of the phosphor and form a layer of silica coating layer on the surface of the phosphor particle. So as to improve the luminous property and service life of the finished product, the packaging experiment: the YAG:Ce phosphor fabricated by the experiment was combined with the blue LED chip to package a white LED device with 1W and assembled into a LED bulb lamp to comprehensively test the performance index of the phosphor. In this study, YAG:Ce phosphors were prepared by liquid-phase precipitation method, and the experimental results provided a theoretical basis for further study.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN312.8

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