以氯化镉和亚碲酸钠为原料、水合肼为还原剂,采用水相合成法制备巯基乙酸(TGA)稳定CdTe量子点(QDS)。研究反应时间、碲和镉的物质的量及巯基乙酸和镉的物质的量之比等实验条件对CdTe量子点发光性能的影响;并用高分辨透射电镜(HRTEM)、X线衍射(XRD)、紫外可见吸收光谱和荧光光谱等分析技术对其进行表征。研究结果表明:合成的量子点为立方晶型,颗粒粒度分布均匀;反应时间及反应物的相对用量对量子点的发光性能有明显影响;随着反应时间的延长,量子点的吸收与荧光光谱都向长波方向移动,在8 h内可获得发绿色到红色荧光的量子点;量子点的发光强度随反应时间的延长而减弱,最高荧光量子产率为27%。
Thioglycolic acid (TGA)-capped CdTe quantum dots (QDs) were prepared in an aqueous medium with CdC12 and Na2TeO3 as raw materials and N2H4 as reductant. The influence of experimental conditions, including refluxing time, molar ratio of tellurium to cadmium and TGA to cadmium, on the luminescent properties of the obtained CdTe QDs was systematically investigated. Furthermore, the obtained QDs were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD), ultraviolet-visible spectroscopy and fluorescent spectroscopy, respectively. The results show that the obtained QDs are of zinc-blended crystal structure. The growth time and the relative quantities of reactants impact the optical properties of QDs. The absorption and fluorescence spectra of QDs move to longer wavelengths with the increase of refluxing time. The CdTe QDs with the emission color ranging from green to red can be synthesized in 8 h. The fluorescence intensity of QDs decreases with the increase of the refluxing time, and the maximum quantum yield is 27%.