微波加热法水相合成梯度合金CdSeS量子点及其环境暴露下荧光稳定性研究

采用微波辅助加热法在水相中一步合成了梯度合金CdSeS量子点,荧光光谱和紫外吸收光谱表明,合成的CdSeS合金量子点具有较高的量子产率(30%左右)。X射线衍射分析和光电子能谱表征证明,合成的CdSeS量子点具有立方晶型,梯度合金结构,内部以CdSe为主,而外部主要以CdS为主;电子透射显微镜下观察到的量子点结晶度高,粒径小(仅2~3 nm),粒度分布均一。在此基础上探讨了所合成的合金量子点在氧化剂过氧化氢、不同的酸碱介质中及350 W氙灯的作用下其荧光光谱的稳定性。结果表明,该合金量子点的光稳定性与CdTe QDs相当,但具有更好的抗氧化性能和抗酸刻蚀性能,具有良好的应用前景。

Microwave-Assisted Synthesis of Water-Dispersed Gradient Alloyed CdSeS Quantum Dots and the Fluorescence Stability Study under Environmental Exposure

The study developed a facile method for the synthesis of water-dispersed gradient alloyed CdSeS QDs using microwave irradiation. The results of UV-Vis absorption spectra and fluorescence spectra showed the obtained QDs have a good photoluminescent quantum yield (PLQY, 30%). The characterizations of XRD and XPS proved that the CdSeS QDs possess a cubic phase with a CdSe-rich core and a thick CdS shell. The analysis of TEM and HRTEM implied the alloyed CdSeS QDs exhibit high crystallinity, small particle size (2~3 nm) and homogeneous size distributions. On the basis, the spectral stabilities of the obtained alloyed CdSeS QDs under environmental exposure such as oxidation, acid and Xenon lamp irradiation were also discussed. The results proved the obtained QDs present the same stability to that of CdTe QDs under Xenon lamp irradiation, but higher stability in an oxidative and acidic environment, which have wide applications in bio-labelling and imaging.