基于PEG修饰的ZnO量子点光学特性研究

采用溶胶-凝胶法制备了ZnO量子点, 并采用有机高分子试剂PEG(聚乙二醇, M_w=2000)对其表面进行修饰。借助X射线衍射分析、傅立叶红外光谱、光致发光谱和透射显微镜等测试方法, 研究了PEG表面修饰对ZnO量子点结构和光学性能的影响规律。研究表明, 混合加入的PEG聚合物能够成功地包覆在ZnO量子点表面, 但没有改变量子点的晶体结构, 经PEG表面修饰后的ZnO量子点尺寸变小, 稳定性增强, 分散更均匀。同时经PEG修饰的ZnO量子点在400~500 nm波长区域缺陷态发射峰明显减弱, 表明采用PEG来改善ZnO量子点表面缺陷结构具有良好效果。

Optical Characteristics of Zinc Oxide Nanoparticles with Surface Modification Using Polyethylene Glycol

Surface of Zinc oxide (ZnO) nanoparticles prepared by Sol-Gel method was modified by a polymer reactant, PEG (polyethylene glycol, M_w=2000). The structure and optical properties of the PEG modified nanoparticles were then investigated by X-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, transmission electron microscopy. Results showed that the added PEG polymers were successfully coated on the surface of ZnO nanoparticles, without obvious variation being found in the ZnO crystal structure. The ZnO particles tend to have a smaller size, better stability and better dispersible uniformity after PEG coating. Furthermore, a defect state emission peak with significantly reduced intensity was found at the range of 400-500 nm in photoluminescence spectra, indicating that the surface defects of ZnO nanoparticles could be well improved by PEG modification.