Co^(2+)掺杂水溶性ZnS量子点的制备及其光致发光性能

Preparation and Photoluminescence Properties of Co^(2+)-Doped Water-Soluble ZnS Quantum Dots

采用共沉淀法,以3-巯基丙酸为表面修饰剂,成功制备出Co2+掺杂水溶性ZnS量子点。采用X射线衍射仪、透射电子显微镜、原子发射光谱仪、紫外-可见吸收光谱仪和荧光分光光度计等,研究了Co2+掺杂剂及掺杂量对ZnS量子点的晶体结构、形貌和发光性能等的影响。结果表明:所得产物均为ZnS立方型闪锌矿结构,量子点呈不规则球形,粒径主要集中在5.2 nm左右;掺杂样品发红色荧光,发光性能明显增强,属于Co2+形成的杂质能级(4A1—4T1)与缺陷的复合发光。同时,利用红外吸收光谱对Co2+掺杂水溶性ZnS量子点的形成机理进行了初步探讨。

Using 3-Mercaptopropionic acid（MPA） as surface coated agent, Co^2＋doped water-soluble quantum dots of ZnS were synthesized by co-precipitation method. The effects of Co^2＋ dopant and doping amount on microstructure, morphology and photoluminescence properties of the As-products were researched by X-ray diffraction, transmission electron microscopy, UV-visible absorption spectrometer and fluorescence spectrophotometer. The results show that the products were irregular spherical cubic zinc blender ZnS with sizes around 5.2 nm. Photoluminescence spectra analysis shows that Co^2＋doped ZnS quantum dots formed a recombination centers with impurity level and defect, the luminescent properties of the doped products are increased obviously by emitting red fluorescence. The synthesis mechanism of Co^2＋ doped ZnS quantum dots was studied by infrared soectroscopy.