以巯基丙酸为稳定剂的水溶性CdTe量子点的水热合成及表征

以巯基丙酸(MPA)为稳定剂,采用水热合成方法在160 ℃下合成水溶性CdTe量子点。研究了不同反应时间及反应前驱体溶液的不同pH值对合成的CdTe量子点光学性质的影响。结果表明:所制得的CdTe量子点的荧光发射波长在510~661 nm范围内连续可调,并且CdTe量子点的光学性质强烈地依赖于反应前驱体溶液的pH值,最佳pH值为9。透射电子显微镜和X射线衍射分析表明所制备的CdTe量子点的形状接近于球形,粒径分布较均匀。与回流方法制备的水溶性量子点相比,高温条件下的水热合成方法简单,反应时间短,CdTe量子点生长速度快,100 min就可生长到3.5 nm,并且所制得的CdTe量子点荧光强度高,稳定性好,荧光量子产率也较高,最高可达44.6%。

Hydrothermal Synthesis and Characterization of Mercaptopropionic Acid Modified Water-soluble CdTe Quantum Dots

Mercaptopropionic acid (MPA) modified high quality CdTe quantum dots (QDs) were prepared by hydrothermal synthesis method in a high temperature. The influences of different reaction time and different pH value of the reactive precursor solution on the optical properties of CdTe QDs were studied. The results indicate that the fluorescence emission wavelength of the as-prepared CdTe QDs can be adjusted continuously at a range of 510~661 nm, and the optical properties of CdTe QDs strongly depend on the pH value of the reactive precursor solution(the optimum pH value is 9). The samples were characterized by transmission electron microscopy and X-ray diffraction. The results show that the shape of the as-prepared CdTe QDs is closed to sphere, and the particle size distribution is uniform. Comparing with the reflux method for preparing water-soluble QDs, the hydrothermal synthesis method at a high temperature is relatively simple, and the reaction time is shorter, the growth of CdTe QDs is faster, the particle size can be grown to 3.5 nm within 100 min. The as-prepared CdTe QDs possess higher fluorescence intensity, good stability and higher fluorescence quantum yield (up to 44.6%).