水溶性CdTe/CdS量子点的制备及发光特性

Preparation of Water Soluble CdTe/CdS Quantum Dots and It′s Luminescence Properties

采用水相合成法,以三种不同的稳定剂:巯基乙醇,巯基乙酸和巯基乙胺制备了CdTe/CdS核壳结构的量子点.研究了反应时间和稳定剂的种类对量子点荧光的光学特性的变化趋势的影响.结果表明,随着量子点晶体生长时间的增加,量子点的荧光峰向红移,荧光发射强度增加,半峰宽几乎保持不变.稳定剂的种类对量子点的荧光发射峰的波长有较大的影响.采用CdS对CdTe进行包裹,制备壳核结构的CdTe/CdS量子点.包裹后能增强水相制备过程中量子点在水相中的荧光强度和发光稳定性,改变量子点的荧光特性.采用红外光谱,对稳定剂和量子点之间的连接关系进行了初步探讨,并采用透射电子显微镜,对CdTe/CdS量子点的微观形态进行观察.

CdTe/CdS quantum dots are prepared by water-phase synthesis method using three kinds of stabilizing agents such as mercaptoethanol,thioglycolic acid and mercaptoethylamine.The fluorescence of quantum dots vary with growth time and types of stabilizers.The results show that the emission peak undergoes a red shift with the growth time,the FWHM,and the strength of emission peak increasing.The type of stabilizers has a dramatic effect on the emission peak.After covering CdTe with CdS,the fluorescence intensity and light stability of quantum dots are improved.The samples are also characterized by infrared spectrum and transmission electron microscopy.The relationship between the stabilizers and the quantum dots is further analyzed.