均相沉淀法论文稀土掺杂氧化物纳米发光材料的制备与性能研究

1、均相沉淀法论文：稀土掺杂氧化物纳米发光材料的制备与性能研究【中文摘要】稀土发光材料在平板显示、绿色照明、光通讯及激光器件等领域有着广泛应用。稀土氧化物是优良的发光基质材料；而且,稀土掺杂纳米发光材料表面包覆一层无掺杂的基质材料降低表面缺陷,对纳米材料的发光性能具有一定的改善。本文采用均相沉淀法、水热法和溶胶-凝胶法制备出了不同形貌的氧化物发光材料以及表面包覆基质的发光材料。获得了一些有意义的研究结果：1.采用均相沉淀法成功的合成出均匀球形的Gd2O3:Eu3+发光材料和不同壳层厚度的Gd2O3:Eu3+Y2O3核-壳结构的发光材料,重点研究了Gd2O3:Eu3+表面包覆不同厚度的基质Y203后

2、对发光性的影响,发现当核层与壳层的厚度比R=4：1时的发光强度比未包覆的Gd2O3:Eu3+增强,认为核-壳型样品降低了纳米Gd2O3:Eu3+表面效应给发光强度带来的负面影响。2.采用均相沉淀法成功的合成出了不同Eu3+掺杂浓度的球形Y2O3:Eu3+发光材料和不同掺杂浓度的Y203:Eu3+Gd203核壳结构发光材料。荧光光谱表明：Y2O3:Eu3+球形颗粒的表面包覆基质Gd2O3后,发光强度比未包覆的Y2O3:Eu3+增强,核壳结构粒子和单一粒子发光强度的差别与Eu3+离子的猝灭浓度有关。3.采用水热法制备出了球形的YVO4:Eu3+发光材料,并用该法在其表面包覆基质材料GdVO4,形成

3、核壳结构的YVO4:Eu3+GdVO4发光材料。荧光光谱表明,YVO4:Eu3+表面包覆GdVO4之后,发射光强度比未包覆的YVO4:Eu3+曾强。4.(1)利用溶胶-凝胶法制备出了表面光滑的GdVO4:Eu3+粒子以及核壳结构的GdVO4:Eu3+GdVO4发光材料。包覆前直径约310nm,包覆层厚度约45nm左右。(2)采用水热法制备出了三明治结构的GdVO4:Eu3+以及核壳结构的GdVO4:Eu3+ YVO4发光材料,包覆前直径约310nm,厚度约110nm左右。包覆层厚度为10nm。荧光光谱表明：以上两种方法制备出的核壳结构的GdVO4:Eu3+LnVO4 (Ln=Gd,Y)发光强度

4、比未包覆的增强。【英文摘要】Rare earth luminescence materials are widely used in the fields of flat panel display, green lighting, optical communications and laser devices. Rare earth oxides are excellent matrixes for luminescent materials. Rare earth doped luminescent nanomaterials coated with a layer of undoped

5、 matrix materials can reduce surface defects of nanomaterials, which would improve the photoluminescence properties. In this dissertation, rare earth oxides luminescence nanomaterials with different morphologies were synthesized with homogeneous precipitation, hydrothermal and sol-gel method. Some m

6、eaningful results were obtained. The results were summarized as follows:1. Uniform spherical Gd2O3:Eu3+ luminescence nanomaterials with different Eu3+ doping concentration and Gd2O3:Eu3+Y2O3 core-shell structural composite particles with different shell thickness were prepared by homogeneous precipi

7、tation method. Photoluminescence properties of Gd2O3:Eu3+ nanoparticles coating with different thickness of Y2O3 host on the surface were mainly studied. It is found that when the coating thickness is suitable, that is Gd2O3:Eu3+/Y2O3 ratio of R=4:1, the luminescence intensities of core-shell partic

8、les are higher than that of the Gd2O3:Eu3+ core nanocrystals, it is thought that the core-shell samples decrease the negative effects of nanoparticles on the luminescence properties.2. Uniform spherical Y2O3:Eu3+ luminescence nanomaterials and Y2O3:Eu3+Gd2O3 core-shell structural composite particles

9、 with different Eu3+ doping concentration were prepared by homogeneous precipitation method. Photoluminescence properties show that the luminescence intensities of core-shell composite particles are higher than that of the Y2O3:Eu3+ core nanocrystals. It is thought that the intensity difference betw

10、een core-shell structure and un-coated nanoparticles was related to the quenching concentration of Eu3+3. Spherical YVO4:Eu3+ luminescence nanoparticles and YVO4:Eu3+GdVO4 core-shell structural composite particles were synthesized by hydrothermal method. Photoluminescence spectra show that the lumin

11、escence intensities of YVO4:Eu3+GdVO4 core-shell composite particles are higher than that of the YVO4:Eu3+ core particles.4. (1) GdVO4:Eu3+ and GdVO4:Eu3+GdVO4 luminescence materials with smooth surface were prepared by sol-gel method. The diameter of un-coated sample is 310 nm, and the thickness of

12、 coating layer is about 45 nm.(2) Sandwich structure GdVO4:Eu3+ and GdVO4:Eu3+YVO4 core-shell structural particles were prepared by hydrothermal method. The diameter of un-coated samples is 335 nm and the thickness is 110 nm. The thickness of coating layer is about 10 nm.Photoluminescence spectra sh

13、ow that the luminescence intensities of core-shell GdVO4:Eu3+LnVO4 (Ln=Gd, Y) composite particles are higher than that of GdVO4:Eu3+ core particles fabricated by the above two methods.【关键词】均相沉淀法 水热法 溶胶-凝胶法 核壳 纳米发光材料 稀土氧化物 表面效应 浓度猝灭【英文关键词】Homogeneous precipitation Hydrothermal method Sol-gel Core-she

14、l Huminescence nanomaterials Rare earth oxides Surface effect Concentration quenching【目录】稀土掺杂氧化物纳米发光材料的制备与性能研究摘要4-5ABSTRACT5目录6-9第一章 绪论9-281.1 发光概述9-131.1.1 发光的基本原理91.1.2 稀土离子的能级和发光特性9-121.1.3 稀土离子的能量传递12-131.2 稀土纳米发光材料的制备方法13-211.2.1 沉淀法14-151.2.2 水热法15-181.2.3 溶胶-凝胶法18-201.2.4 微乳液法201.2.5 燃烧法201.2

15、.6 其他制备方法20-211.3 核壳结构的纳米发光材料21-261.3.1 以稀土磷酸盐为基质的核壳结构发光材料21-231.3.2 以稀土氟化物为基质的核壳结构发光材料23-251.3.3 以稀土氧化物为基质的核壳结构发光材料251.3.4 其他核壳结构的发光材料25-261.4 本文研究的目的和意义26-28第二章 实验试剂、仪器及表征方法28-302.1 主要实验试剂282.2 实验仪器28-292.3 表征方法29-302.3.1 X射线衍射(XRD)分析292.3.2 傅立叶变换红外光谱(FTIR)分析292.3.3 场发射环境扫描电子显微镜(FESEM)分析292.3.4 光电

16、子能谱(XPS)分析292.3.5 荧光光谱分析29-30第三章 Gd_2O_3:Eu(3+)和Gd_2O_3:Eu(3+)Y_2O_3发光材料的制备与发光性能30-393.1 概述303.2 实验部分30-313.2.1 Gd_2O_3:Eu(3+)粒子的制备30-313.2.2 Gd_2O_3:Eu(3+)Y_2O_3复合粒子的制备313.3 结果与讨论31-383.3.1 X射线衍射分析31-323.3.2 红外光谱分析323.3.3 扫描电镜分析32-353.3.4 光电子能谱分析35-363.3.5 荧光光谱分析36-383.4 本章小结38-39第四章 Y_2O_3:Eu(3+)和

17、Y_2O_3:Eu(3+)Gd_2O_3发光材料的制备与表征39-494.1 概述394.2 实验部分39-404.2.1 不同掺杂浓度的Y_2O_3:Eu(3+)的制备394.2.2 不同掺杂浓度的Y_2O_3:Eu(3+)Gd_2O_3的制备39-404.3 结果与讨论40-474.3.1 X射线衍射分析404.3.2 红外光谱分析40-414.3.3 扫描电镜分析41-444.3.4 光电子能谱分析44-454.3.5 荧光光谱分析45-474.4 本章小结47-49第五章 YVO_4:Eu(3+)和YVO_4:Eu(3+)GdVO_4发光材料的制备与表征49-575.1 概述495.2 实验部分49-505.2.1 YVO_4:Eu(3+)粒子的制备49-505.2.2 YVO_4:Eu(3+)GdVO_4复合粒子的制备505.3 结果与讨论50-565.3.1 X射线衍射分析505.3.2 红外光谱分析50-515.3.3 扫描电镜分析51-545.3.4 光电子能谱分析545.3.5 荧光光谱分析54-565.4 本章小结56-