3-巯基丙酸稳定的CdSe量子点的制备及其荧光性能

以CdCl₂·2.5H₂O,Na₂SeO₃和NaBH₄为反应物，制备3-巯基丙酸稳定的CdSe量子点.研究了加热回流时间、镉和硒的物质的量及镉和3-巯基丙酸的物质的量之比等实验条件对CdSe量子点光谱性能的影响.采用紫外-可见光谱、荧光光谱、X射线粉末衍射和高分辨透射电镜等分析手段，对量子点的光学性能和结构进行表征.结果表明，反应时间、镉和硒的物质的量及镉和3-巯基丙酸的物质的量之比等实验条件对CdSe量子点的光谱性能有明显影响；不同条件下制备的量子点的荧光发射峰的半峰宽保持在35~40 nm范围内；所得CdSe量子点为立方晶型.在pH值为11.0，且nCd∶nSe∶nMPA=1∶0.2∶1.1的条件下，回流90 min制备的量子点的荧光量子产率值可达16.1%.

Synthesis and Fluorescence Spectra Analysis of 3-Mercaptopropionic Acid Stabilized CdSe Quantum Dots

Cadmium selenide quantum dots （QDs） were prepared by the reaction of CdCl2 . 2. 5H2O, Na2SeO3 and NaBH4 in water and in the presence of 3-mercaptopropionic acid （MPA） as stabilizer. The influences of experimental conditions,including refluxing time, cadmium to selenium molar ratio and cad- mium to MPA molar ratio,on the luminescent properties of the obtained CdSe QDs were systematically investigated. Furthermore, the obtained QDs were characterized by UV-vis absorption spectra, photoluminescence （PL） spectra,X-ray powder diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）. Experimental results indicated that the refluxing time and the relative quantities of reactants impacted the optical properties of QDs. The proposed method enabled us to obtain cubic CdSe QDs with narrow fluorescence full width at half maximum （35-40 nm）. It was found that 16.1% of photoluminescence quantum yield was achieved when reaction system was refluxed 0,and ncd ： nse nMPA= 1 ： 0. 2 ： 1. 1.