SiO2@Gd2O3∶Tb^3+核壳微球的可控合成及发光性能研究  

Controllable Synthesis and Luminescent Properties of SiO2@Gd2O3:Tb^3+Core-Shell Microspheres

作　　者：陈杰 姜海峰 高忆欣 王珊珊 高艳 曾晓丹 CHEN Jie;JIANG Haifeng;GAO Yixin;WANG Shanshan;GAO Yan;ZENG Xiaodan(Analysis and Testing Center,Jilin Institute of Chemical Technology,Jilin 132022,China;School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]吉林化工学院,分析测试中心,吉林132022 [2]东北电力大学,能源与动力工程学院,吉林132012

出　　处：《人工晶体学报》2020年第7期1201-1207,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金(51902125);吉林化工学院重大科技项目(2018022)。

摘　　要：采用简便的尿素辅助沉淀法将Gd2O3∶Tb^3+成功包覆在二氧化硅微球表面合成了尺寸均匀的球形SiO2@Gd2O3∶Tb^3+核壳发光材料,解决了稀土发光材料普遍存在的形貌可控性差和颗粒尺寸不均一等问题。利用XRD、SEM、红外光谱和荧光光谱等表征测试了样品的形貌、结构和发光性能。SEM照片和尺寸分布图显示,SiO2@Gd2O3∶Tb^3+粒子呈现均匀球形形貌,分散性良好,粒径约(608±18) nm。XRD图谱分析表明,600℃煅烧后,壳层Gd(OH)3CO3完全转变为立方相Gd2O3,结晶性良好,无杂相生成。同时,结合红外光谱推测了SiO2@Gd2O3∶Tb^3+核壳微球的形成机理,并得出Gd2O3∶Tb^3+壳层主要以Si-O-Gd键形式连接在二氧化硅微球表面。在240 nm紫外光激发下,SiO2@Gd2O3∶Tb^3+核壳微球呈现绿光发射,其中,位于540 nm处的主峰归属于Tb^3+的5D4→7F5能级跃迁。不同Tb^3+掺杂浓度下的发射光谱表明,当Tb^3+掺杂浓度为4mol%时,SiO2@Gd2O3∶Tb^3+核壳微球的发射强度达到最大值,寿命为1.55 ms,色坐标位于绿色区域,展现了良好的绿光发光性能。The spherical SiO2@Gd2O3∶Tb^3+ core-shell luminescent materials with uniform size were successfully prepared by coating Gd2O3∶Tb^3+ on the surface of silica nanospheres by a simple urea assisted precipitation method, which solves the common defects of rare earth luminescent materials, such as uncontrollable morphology and uneven size. The morphology, structure and luminescence properties of as-prepared samples were investigated by XRD, SEM, FT-IR and photoluminescence spectra. The SEM images and size distributions show that the as-prepared SiO2@Gd2O3∶Tb^3+ particles exhibit uniform spherical morphology and good dispersion, and the particle size about(608±18)nm. XRD patterns show that the Gd(OH)3CO3 shell is completely transform into cubic phase Gd2O3 with good crystallinity and no impurity after calcination at 600 ℃. At the same time, the formation mechanism of SiO2@Gd2O3∶Tb^3+ core-shell microspheres inferred by FT-IR spectra is concluded that Gd2O3∶Tb^3+ shell is mainly connected to the surface of SiO2 microspheres by forming Si-O-Gd bond. Under the excitation of 240 nm ultraviolet light, the SiO2@Gd2O3∶Tb^3+ core-shell microspheres show green emission peaks of Tb^3+, and the main peak at 540 nm correspond to the 5D4→7F5 transition. The luminescence intensity of SiO2@Gd2O3∶Tb^3+ core-shell microspheres reaches the maximum value when the doping concentration of Tb^3+ is 4 mol%, and the lifetime is 1.55 ms. The CIE color coordinates of SiO2@Gd2O3∶4%Tb^3+ core-shell microspheres is located in the green region, showing good green light-emitting performance.

关 键 词：SiO2@Gd2O3∶Tb^3+ 核壳微球 尿素沉淀法 发光性能 

分 类 号：O734[理学—晶体学]