中文摘要：

采用均匀沉淀法,通过改变稀土离子与尿素的量比成功合成了粒径分别为80,55,40 nm的Y2O3∶Eu3＋纳米球样品。通过X射线衍射（XRD）、场发射扫描电镜（FE-SEM）和发光光谱对不同尺寸纳米球的晶体结构、微观形貌和发光性质做了分析,对Y2O3∶Eu3＋纳米球的生长过程进行了研究。根据Judd-Ofelt理论,利用Eu3＋的发射光谱和荧光衰减等数据,计算了5D0→7FJ能级的辐射跃迁速率和荧光分支比,计算得到Y2O3基质材料的折射率为1.80以及不同粒径样品的光学跃迁强度参数。最后分析了5D0能级荧光发射与温度之间的依赖关系,结果证明了荧光温度猝灭行为符合Crossover过程,并通过阿伦尼乌斯公式非线性拟合获得了激活能,粒径为80,55,40 nm的Y2O3∶Eu3＋纳米球样品的活化能分别为0.201,0.193,0.200 eV。

英文摘要：

Y2O3doped with Eu3＋nanosphere phosphors with different sizes were synthesized via urea homogeneous precipitation method. By changing the molar ratio of rare earth to urea precipitant,the uniform spherical Y2O3∶ Eu3＋nanoparticles with the sizes of 80,55 and 40 nm were obtained. The phase,morphology and luminescence property of as-prepared samples were characterized by means of X-ray diffraction（ XRD）,filed emission scanning electron microscopy（ FE-SEM） and photoluminescence spectra,respectively. The growth process of Y2O3∶ Eu3＋nanoparticles was studied. The refractive index of Y2O3 was deduced to be about 1. 80. Meanwhile,the radiative transition rates,fluorescence branching ratios and J-O parameters were calculated by using the emission spectra and fluorescence decay. Finally,the temperature dependence of5D0 fluorescence emissions was analyzed. The thermal quenching behavior of5D0 fluorescence followed well the Crossover model. The activation energy of Y2O3∶ Eu3＋nanosphere phosphors with different sizes was obtained from the nonlinear fitting on the temperature quenching of luminescence intensity. The activation energy of Y2O3∶ Eu3＋nanosphere phosphors with the size of 80,55,40 nm are 0. 201,0. 193,0. 200 e V,respectively.