系统考察了水相合成CdTe量子点的主要影响因素,通过改变无水乙醇-水体系的体积,提高NaHTe的合成质量,并调整反应温度,改变反应的初始pH值,在水相中快速合成了量子产率高、粒径分布范围窄的CdTe量子点,实现了对量子点发光性质的调控,在最佳条件(无水乙醇3mL,水1mL,反应初始pH8.0,反应温度40℃)下,最高量子产率达68%.量子点胶体溶液在回流过程中有时产生白色沉淀,放置7d后,未过滤白色沉淀的量子点比过滤后的量子点荧光强度提高15%,白色沉淀还有减小粒径分布的作用.
The rapid aqueous synthesis of CdTe quantum dots modified by thioglycolic acid(TGA) was studied through investigating and improving the factors which influence the synthesis. The control of photoluminescence properties was realized through systematically changing the volume of anhydrous ethanol and water, the temperature and the original pH value. The high-quality CdTe QDs with narrower full width at half maximum of photoluminescence spectra and larger quantum yield were obtained. Under the optimal condition (as the volume of anhydrous ethanol and water is 3 and 1 mL, original pH value is 8.0, the temperature is 40 ℃ ), the maximum quantum yield at room temperature is approximately 68%. A white precipitate emerged during reflux. After depositing for a week, the fluorescence intensity of the QDs with white precipitate was dramatically enhanced by 15% than that of the QDs which the white precipitate was removed. Besides, the white precipitate is preferable for the narrowing of the size distribution.