巯基乙酸稳定的CdSe/ZnS核壳结构量子点的制备与表征

用非均相成核原理,在水溶液中制备CdSe/ZnS核壳结构量子点,并研究合成工艺,包括前驱物的滴加方式和用量、CdSe核的水浴反应时间、CdSe与ZnS的摩尔比等因素对CdSe/ZnS核壳结构量子点荧光性能的影响.用透射电子显微镜和x射线衍射仪测试核壳结构量子点的形貌和结构.用紫外吸收光谱与荧光光谱表征CdSe/ZnS核壳结构量子点的荧光性能.结果表明:ZnS壳层在CdSe核量子点表面外延生长,形成了核壳结构;CdSe/ZnS核壳结构量子点的荧光性能明显高于单一的CdSe量子点;合成的工艺条件会显著影响CdSe/ZnS核壳结构量子点的荧光性能.

PREPARATION AND CHARACTERIZATION OF CdSe/ZnS CORE-SHELL QUANTUM DOTS STABILIZED BY THIGLYCOLLIC ACID

Based on the heterogeneous nucleation theory, the CdSe/ZnS core/shell quantum dots were prepared in aqueous phase using the co-precipitation method. The influence of various factors, such as injection methods and dosages of precursors, water-bathing reaction duration of CdSe and the initial mole ratio of CdSe to ZnS, on the fluorescence properties of the obtained CdSe/ZnS quantum dots was investigated, The morphology and structure of the samples were characterized by transmission electron microscopy and X-ray diffraction. The photoluminescence properties of the CdSe/ZnS core/shell quantum dots were characterized by ultraviolet-visible absorption spectra and photoluminescence spectra. The results showed that epitaxial ZnS shells grow on the surface of CdSe quantum dots and form CdSe/ZnS core/shell quantum dots. The core/shell quantum dots have superior fluorescence properties in comparison to the CdSe plain core quantum dots. The technical conditions of preparation have a strong influence on the photolu- minescence of the CdSe/ZnS core-shell quantum dots.