【作者】 白海英；

【导师】 刘桂霞；

【作者基本信息】 长春理工大学 ， 无机化学， 2011， 硕士

【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)发光强度比未包覆的增强。更多还原

【Abstract】 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 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 meaningful 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 precipitation 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 particles 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 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 between 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 luminescence 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 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 show 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.更多还原