Ce:YAG纳米粉体及透明陶瓷的制备和性能研究
发布时间：2018-08-01 15:10
【摘要】：钇铝石榴石(YAG)属于立方晶系,具有稳定的物理和化学性质,这些特性使YAG广泛应用于结构和功能材料等领域。铈掺杂钇铝石榴石(Ce:YAG)黄色荧光粉,是目前应用最广泛的荧光粉,可与蓝光芯片可以组合制备白光LED,被广泛应用于照明和背光源等领域。目前市场上的产品均是由有机树脂与荧光粉体混合进行封装组合,存在耐热差、热导率低、易老化和发光不均等问题,将Ce:YAG荧光粉体制备成透明陶瓷作为LED背光源和封装材料可以明显改善上述问题。论文采用冲击射流反应法(CIJR)合成Ce:YAG纳米荧光粉体,使用真空高温烧结技术制备Ce:YAG透明陶瓷。系统研究了粉体合成工艺、熔盐法煅烧粉体、部分稀土元素掺杂对Ce:YAG荧光粉体性能的影响,探讨了添加剂、烧结温度、保温时间等因素对制备透明陶瓷的影响,利用SEM、XRD、PL等仪器分析手段对制备的粉体和陶瓷进行了表征。CIJR反应器合成的粉体具有优秀的分散性和荧光性能,合成工艺条件为:加料速度10m L/min,(NH4)2SO4分散剂2wt%,Ce掺杂量3.0%;前驱体经过1000℃煅烧5h获得纯YAG相。论文探讨了熔盐(KCl)法煅烧Ce:YAG荧光粉体的影响,最佳煅烧工艺为熔盐用量R=1:3,在900℃煅烧8h能够得到晶粒较为规则且荧光强度较强的粉体,同时添加10wt%的Ba Cl2能够有效的减小晶粒的粒。论文研究了三种稀土元素Gd、Tb、Pr掺杂对Ce:YAG荧光粉体的影响:Gd和Tb均能使Ce:YAG的发射峰发生红移,Pr的掺杂会在609nm处增加发射峰,虽然掺杂都能增加红光成分,但是会降低荧光粉体的荧光强度,通过正交实验优化出最佳荧光粉体组成为(Y0.67Gd0.2Tb0.1Ce0.03)3Al5O12。采用三步烧结工艺制备Ce:YAG透明陶瓷,烧结助剂TEOS和Mg O,能够在较低的温度下产生液相,并且均能有效减少晶粒异常生长,用量过多将会引入第二相,最佳添加量为0.8wt%TEOS和0.01wt%Mg O。在真空烧结炉中将坯体加热至1280℃和1400℃各保温2h,接着升温至1680℃烧结8h,降温取出后在空气氛中1450℃退火2h,最后经打磨和抛光得到透明陶瓷,其在800nm处最大的透过率为16.3%。通过调节陶瓷片的厚度可以调节效率、色温、显色指数等,能够得到白光,由于缺少红光成分,显色指数最高为57.3,离标准白光存在差距。
[Abstract]:Yttrium aluminum garnet (YAG) belongs to cubic system and has stable physical and chemical properties. These properties make YAG widely used in structural and functional materials. Ce doped yttrium aluminum garnet (Ce:YAG) yellow phosphor is the most widely used phosphor. It can be combined with blue chip to prepare white LED. At present, all the products on the market are encapsulated by organic resin and phosphor, which have the problems of poor heat resistance, low thermal conductivity, easy aging and uneven luminescence. Transparent ceramics prepared from Ce:YAG phosphors can be used as backlight source and packaging material for LED. In this paper, Ce:YAG nanocrystalline phosphors were synthesized by impinging jet reaction method (CIJR) and Ce:YAG transparent ceramics were prepared by vacuum high temperature sintering. The effects of powder synthesis, molten salt calcination and rare earth element doping on the properties of Ce:YAG phosphors were systematically studied. The effects of additives, sintering temperature and holding time on the preparation of transparent ceramics were discussed. The powder and ceramics prepared by SEMX XRDPL were characterized by means of SEM, XRDPL and other instruments. The powders synthesized in the reactor of .CIJR had excellent dispersibility and fluorescence properties. The synthetic conditions are as follows: (NH4) 2SO4 dispersant, (10 mL 路min), (NH4) 2SO4 dispersant, 2 wtand ce doping amount 3.0 and the precursor calcined at 1000 鈩，
本文编号：2157968
[Abstract]:Yttrium aluminum garnet (YAG) belongs to cubic system and has stable physical and chemical properties. These properties make YAG widely used in structural and functional materials. Ce doped yttrium aluminum garnet (Ce:YAG) yellow phosphor is the most widely used phosphor. It can be combined with blue chip to prepare white LED. At present, all the products on the market are encapsulated by organic resin and phosphor, which have the problems of poor heat resistance, low thermal conductivity, easy aging and uneven luminescence. Transparent ceramics prepared from Ce:YAG phosphors can be used as backlight source and packaging material for LED. In this paper, Ce:YAG nanocrystalline phosphors were synthesized by impinging jet reaction method (CIJR) and Ce:YAG transparent ceramics were prepared by vacuum high temperature sintering. The effects of powder synthesis, molten salt calcination and rare earth element doping on the properties of Ce:YAG phosphors were systematically studied. The effects of additives, sintering temperature and holding time on the preparation of transparent ceramics were discussed. The powder and ceramics prepared by SEMX XRDPL were characterized by means of SEM, XRDPL and other instruments. The powders synthesized in the reactor of .CIJR had excellent dispersibility and fluorescence properties. The synthetic conditions are as follows: (NH4) 2SO4 dispersant, (10 mL 路min), (NH4) 2SO4 dispersant, 2 wtand ce doping amount 3.0 and the precursor calcined at 1000 鈩，
本文编号：2157968
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