Li G Z, Yu M, Wang Z L, Lin J, Wang R S, Fang J
Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
J Nanosci Nanotechnol. 2006 May;6(5):1416-22. doi: 10.1166/jnn.2006.195.
A uniform nanolayer of europium-doped Gd2O3 was coated on the surface of preformed submicron silica spheres by a Pechini sol-gel process. The resulted SiO2 @ Gd2O3:Eu3+ core-shell structured phosphors were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as kinetic decays. The XRD results show that the Gd2O3:Eu3+ layers start to crystallize on the SiO2 spheres after annealing at 400 degrees C and the crystallinity increases with raising the annealing temperature. The core-shell phosphors possess perfect spherical shape with narrow size distribution (average size: 640 nm) and non-agglomeration. The thickness of the Gd2O3:Eu3+ shells on the SiO2 cores can be adjusted by changing the deposition cycles (70 nm for three deposition cycles). Under short UV excitation, the obtained SiO2@Gd2O3:Eu3+ particles show a strong red emission with 5D0-7F2 (610 nm) of Eu3+ as the most prominent group. The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.
通过佩琴尼溶胶 - 凝胶法在预先形成的亚微米二氧化硅球表面包覆了一层均匀的铕掺杂氧化钆纳米层。通过X射线衍射（XRD）、傅里叶变换红外光谱（FT - IR）、场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）、光致发光（PL）光谱以及动力学衰减对所得的SiO₂@Gd₂O₃:Eu³⁺核壳结构荧光粉进行了表征。XRD结果表明，Gd₂O₃:Eu³⁺层在400℃退火后开始在SiO₂球上结晶，并且结晶度随着退火温度的升高而增加。核壳荧光粉具有完美的球形，尺寸分布窄（平均尺寸：640 nm）且无团聚。SiO₂核上Gd₂O₃:Eu³⁺壳层的厚度可以通过改变沉积循环次数来调节（三个沉积循环时为70 nm）。在短紫外激发下，所得的SiO₂@Gd₂O₃:Eu³⁺颗粒表现出强烈的红色发射，其中Eu³⁺的⁵D₀→⁷F₂（610 nm）作为最突出的峰。Eu³⁺的PL强度随着退火温度和包覆循环次数的增加而增加。
