Wang Ze, Qian Benfu, Wang Fangke, Zhao Qianran, Wang Yulu, Zou Haifeng, Song Yanhua, Zhou Xiuqing, Sheng Ye
College of Chemistry, Jilin University, Changchun 130012, P. R. China.
Inorg Chem. 2021 Feb 15;60(4):2542-2552. doi: 10.1021/acs.inorgchem.0c03445. Epub 2021 Jan 22.
Uniform and well-dispersed SiO:%Tb@LuO:%Eu core-shell spherical phosphors were synthesized via a solvothermal method followed by a subsequent calcination process. The structure, phase composition, and morphology of the samples were studied by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that the LuO:Eu layer was evenly coated on the surface of SiO:Tb spheres and the shell thickness was about 45-65 nm. The PL spectra and fluorescence lifetimes of the samples were further studied. It was proved that the multicolor luminescence of the samples could be realized by changing the doping concentration ratio of Eu or by changing the excitation wavelengths. Compared with SiO@LuO:3%Tb,6%Eu, SiO:3%Tb@LuO:6%Eu showed stronger luminescence intensity, longer fluorescence lifetime, and higher energy transfer efficiency, which was attributed to the effective interfacial energy transfer, and the interfacial energy transfer mechanism from Tb to Eu was a dipole-dipole interaction mechanism. The XPS results indicated that the sample contained a high content of Si-O-Lu bonds, which proved that there was a strong interaction between the SiO core and the LuO shell, making the interfacial energy transfer possible. These results provided a new idea for luminescence enhancement and multicolor luminescence.
通过溶剂热法并随后进行煅烧过程，合成了均匀且分散良好的SiO₂:Tb@Lu₂O₃:Eu核壳球形荧光粉。通过X射线衍射（XRD）、热重分析（TGA）、傅里叶变换红外光谱（FT-IR）、场发射扫描电子显微镜（SEM）和透射电子显微镜（TEM）研究了样品的结构、相组成和形貌。结果表明，Lu₂O₃:Eu层均匀包覆在SiO₂:Tb球表面，壳层厚度约为45-65nm。进一步研究了样品的PL光谱和荧光寿命。结果表明，通过改变Eu的掺杂浓度比或改变激发波长，可以实现样品的多色发光。与SiO₂@Lu₂O₃:3%Tb,6%Eu相比，SiO₂:3%Tb@Lu₂O₃:6%Eu具有更强的发光强度、更长的荧光寿命和更高的能量转移效率，这归因于有效的界面能量转移，且从Tb到Eu的界面能量转移机制为偶极-偶极相互作用机制。XPS结果表明样品含有高含量的Si-O-Lu键，这证明SiO₂核与Lu₂O₃壳之间存在强相互作用，使得界面能量转移成为可能。这些结果为发光增强和多色发光提供了新思路。
