水溶性的高荧光CdTe/CdSeⅡ型核壳量子点的合成与表征

Synthesis and Characterization of High Fluorescence, Type-Ⅱ Core/Shell CdTe/CdSe Quantum Dots in Aqueous Medium

用L-半胱氨酸(L-cysteine)作为稳定剂,以制备的CdTe量子点为核模板,水相合成了具有近红外发光的Ⅱ型核壳CdTe/CdSe半导体量子点。实验考察了合成温度,核模板的尺寸和组分比等因素对合成高质量的CdTe/CdSe量子点的影响。用紫外-可见吸收和荧光光谱研究了合成的量子点的光学性质。在优化的合成条件下,荧光发射光谱在586～753nm范围连续可调,荧光量子产率高达68%;通过X-射线衍射(XRD),X射线光电子能谱(XPS)和透射电镜(TEM)对合成的Ⅱ型核壳CdTe/CdSe量子点进行了结构和形貌表征。

Water-soluble Type-Ⅱ CdTe/CdSe core/shell quantum dots （QDs） with high fluorescence have been synthesized using cysteine-capped CdTe as core template. The experimental results showed that the synthesis conditions including the synthetic temperature, size of core template and the molar ratios of core template to shell material played an important role in the photoluminescence （PL） of the as-prepared CdTe/CdSe core/shell QDs. The optical properties of CdTe/CdSe core/shell QDs were investigated by employing UV-Vis, photoluminescence and fluorescence decay spectroscopy. Under optimal condition, the PL spectra of CdTe/CdSe QDs could be continuously adjustable with the PL wavelength ranged from 586 to 753 nm with various reflux time, and the maximum PL QY was about 68% at room temperature. XRD, XPS and TEM were used to characterize the size, shape, and composition of CdTe/CdSe core/shell QDs.