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采用直接沉淀法成功制备了Ag@SiO2@GdF3:Er,Yb核壳结构纳米上转换发光粒子,并用XRD,TEM,UV-Vis,FTIR以及荧光光谱等对其结构和发光性能进行了表征.XRD分析表明:Ag表面包覆上了结晶良好的正交晶系的GdF3:Er,Yb.TEM照片显示:制备的复合纳米粒子具有明显的球形核壳结构,内核Ag粒子的直径约50 nm左右,包覆后的Ag@SiO2@GdF3:Er,Yb粒径约为80~120 nm,表面光滑且包覆完全.UV-Vis光谱证明:GdF3:Er,Yb和SiO2成功包覆在Ag核表面,包覆后Ag纳米粒子的表面等离子体共振吸收峰发生了红移.荧光光谱表明:在980 nm激光激发下,该复合纳米粒子显示出和纯的GdF3:Er,Yb相同的Er3+的特征红色和绿色上转换发光,以位于655 nm处的Er3+离子的4F9/2→4I15/2的红光发射最强,并且复合粒子的发射光强度比纯的GdF3:Er,Yb有所增强.
The structure and luminescent properties of Ag @ SiO2 @ GdF3: Er, Yb core-shell nanostructured upconverted luminescent particles were successfully prepared by direct precipitation method and characterized by XRD, TEM, UV-Vis, FTIR and fluorescence spectroscopy. The results show that: the surface of Ag coated with the crystal of good orthorhombic GdF3: Er, Yb.TEM photos show: the prepared composite nanoparticles with a clear spherical core-shell structure, the inner diameter of Ag particles about 50 nm, The coated Ag @ SiO2 @ GdF3: Er, Yb particle size of about 80 ~ 120 nm, the surface smooth and fully coated.UV-Vis spectra proved: GdF3: Er, Yb and SiO2 successfully coated on the surface of the Ag core, The surface plasmon resonance absorption peaks of Ag nanoparticles were red-shifted after coating.The fluorescence spectra showed that under the excitation of 980 nm, the composite nanoparticles showed the characteristic red and the same Er3 + as GdF3: Er and Yb Green upconversion luminescence, with 4F9 / 2 → 4I15 / 2 red emission of Er3 + ions located at 655 nm is the strongest, and the emission intensity of the composite particles is stronger than the pure GdF3: Er, Yb.