LaF3Eu3红色荧光粉的水热合成和荧光性能 - 图文

惠州学院

HUIZHOU UNIVERSITY

毕 业 论 文（设 计）

中文题目：LaF3:Eu3+

红色荧光粉的水热合成和荧光性能

英文题目：Hydrothermal synthesis and photoluminescence properties of LaF3:Eu3+ red phosphors

姓 名_ 余文锋______ 学 号____100604236_____ 专业班级10应用化学（2）班 指导教师 肖定书

刘国聪

提交日期__________________

教务处制

1

LaF3:Eu3+红色荧光粉的水热合成和荧光性能

化学工程系应用化学 余文锋 指导老师：肖定书 副研究员，刘国聪 教授

（惠州学院化学工程系，广东，惠州，516007）

摘要

稀土掺杂LaF3发光材料因具有优越的物理与化学性能，已广泛应用于LED显示、照明节能、光学通讯和荧光探针等领域。论文以氧化镧、氧化铕、硝酸、氟化钠、十六烷基三甲基溴化铵（CTAB）为原料，采用简单水热法合成了LaF3:Eu3+红色荧光粉，并探讨pH、反应温度以及表面活性剂用量对产物的物相结构、形貌尺寸和荧光性能的影响。研究结果表明，水热产品均是六方晶系的LaF3:Eu3+纳米晶，晶粒尺寸介于20-100 nm内。荧光结果表明，LaF3:Eu3+纳米晶在397 nm(7F0 →5L6 )光源激发下表现出良好的橙红色发射(592 nm,5D0→7F1)。当Eu3+离子掺杂摩尔浓度为9 %时，样品的荧光强度达到最大值，更高的Eu掺杂浓度会引起荧光猝灭。

关键词：水热法；十六烷基三甲基溴化铵；LaF3:Eu3+纳米晶；荧光性能

2

Hydrothermal synthesis and photoluminescence

properties of LaF3:Eu3+ red phosphors

Chemical Engineering Yuwenfeng Instructor：Xiaodingshu Associate research fellow，

Liuguocong Professor

（Chemical Engineering of Huizhou uinversity，Guangdong，Huizhou，516007）

ABSTRACT

LaF3 phosphors doped by rare earth ions have been applied in LED, illuminating and energy source-saving, optics communication and fluorescence probe due to its outstanding physical and chemical properties. With La2O3, Eu2O3, HNO3, NaF, cetyl- trimethyl ammonium bromide (CTAB) as materials, a facile hydrothermal method was adopted to synthesize LaF3:Eu3+ red phosphors, and the effects of the pH value, reaction temperature, and surfactant dosage upon the crystal structure, morphology and fluorescence of the product were investigated in detail. The testing results show that the re-prepared samples are hexagonal LaF3:Eu3+ nanocrystals with the average grain size of 20-100 nm. It is found from the FL testing that all LaF3:Eu3+ nanocrystals have a good orange-red emission (592 nm,5D0→7F1) excited by 397 nm (7F0 →5L6).When the concentration of Eu3+ doped is 9 % (mol), LaF3:Eu3+ nanocrystal exhibits the strongest orange-red emission, but more Eu3+ ions doped easily result in fluorescence quenching.

Key word: Hydrothermal method; cetyl trimethyl ammonium bromide; LaF3: Eu3+

nanocrystal ；fluorescent properties

3

目录

1绪论..................................................................................................................... 5

1.1引言........................................................................................................... 5 1.2 稀土发光材料介绍.................................................................................. 5 1.2.1发光的主要形式.................................................................................... 6 1.2.2稀土材料的发光原理............................................................................ 6 1.2.3 稀土发光材料的应用........................................................................... 6 1.3 课题来源、研究内容和意义.................................................................. 7 2实验及表征部分................................................................................................. 8

2.1 实验仪器及实验试剂.............................................................................. 8 实验所用仪器和药品见表2.1和表2.2。.................................................... 8 2.2 制备过程.................................................................................................. 8 2.3样品表征方法......................................................................................... 11 3样品形貌表征及微量元素分析....................................................................... 11

3.1 XRD谱图分析 ....................................................................................... 11 3.2 SEM扫描电子显微镜下的表征 ........................................................... 12 3.3 样品微量元素分析................................................................................ 13 3.4样品的IR图谱分析............................................................................... 14 3.6 LaF3:Eu3+的荧光性能 ............................................................................ 15 3.5.1 LaF3:Eu3+室温荧光和主要能级跃迁 ................................................. 15 3.5.3 掺杂Eu3+量对LaF3:Eu3+的发光性能的影响 ................................... 18 3.5.3表面活性剂用量对LaF3:Eu3+荧光性能的影响 ................................ 20 3.5.4反应温度对LaF3:Eu3+的发光性能的影响 ........................................ 21 4 结论.................................................................................................................. 22 参考文献.............................................................................................................. 23

4