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通过溶胶凝胶技术制备了掺杂Ce3+离子的纳米SiO2材料,并经较低温度下煅烧,研究其光致发光(PL)性能。X射线衍射(XRD)及透射电子显微镜(TEM)测试结果表明该纳米材料具有非晶态结构,颗粒尺寸为20~30nm。对其光致发光谱的测定显示:经450℃低温煅烧,未掺杂SiO2样品的光致发光谱明显为多峰的宽带结构,而微量Ce3+掺杂的样品在230nm激发下存在着唯一的一个很强的、主峰位于346nm左右的紫外发光峰,与未掺杂SiO2及Cu2+掺杂SiO2样品的比较表明该发光峰并非常见的Ce3+离子的d-f跃迁产生的特征发光带,而是起源于SiO2中的某种本征缺陷中心。通过不同煅烧温度以及不同Ce3+离子掺杂量对346nm发光峰强度的影响,讨论该发光峰起源可能的结构模型。
The nano-SiO2 material doped with Ce3 + ions was prepared by sol-gel technique, and its photoluminescence (PL) properties were studied by calcining at lower temperature. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that the nanomaterial has an amorphous structure with a particle size of 20-30 nm. The photoluminescence (PL) spectra showed that the photoluminescence spectra of undoped SiO2 samples were obviously multimodal when calcined at 450 ℃, while the trace amount of Ce3 + -doped samples had the only one excited at 230 nm The results show that the peak is not characteristic of the df transition of Ce3 + ions, but originated in SiO2 Some kind of intrinsic defect center. Through the influence of different calcination temperature and different doping amount of Ce3 + ions on the emission peak intensity at 346 nm, the possible structural model of the origin of the emission peak is discussed.