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采用高温有机相包覆技术制备了CdSe/ZnS核壳结构量子点材料,考察了包覆量对量子点材料的光学性能的影响,研究了含脂肪链和芳香基的双硫醇分子1,4-苯二甲硫醇和1,8-辛二硫醇对于具有核-壳结构的CdSe/ZnS量子点材料的修饰作用,考察了修饰作用对于量子点的量子效率和荧光强度等光学性能的影响.实验结果表明:随着硫化锌包覆量的增加,量子点的量子效率及其荧光发射强度明显提高;硫醇的修饰能显著增强量子点的发光强度,随着硫醇浓度的增加,其发光性能增强,但是达到一定程度后,光学性能基本不随硫醇浓度的变化而变化.根据固体核磁共振等实验结果推测:硫醇分子可能部分替代了量子点体系中的正三辛基氧膦配体,稳定了量子点体系,对量子点起修饰保护作用,从而提高了量子点的光学性能.
CdSe / ZnS core-shell QDs were prepared by high-temperature organic-phase-coating technique. The effects of the coating amount on the optical properties of CdSe / ZnS core-shell materials were investigated. -dimethylalcohol and 1,8-octanedithiol on the CdSe / ZnS quantum dot material with core-shell structure. The effects of the modification on the optical properties such as quantum efficiency and fluorescence intensity of QDs were investigated. The experimental results show that the quantum efficiency of QDs and the fluorescence emission intensity increase obviously with the increase of ZnS coating amount. The thiol modification can significantly enhance the emission intensity of QDs. With the increase of thiol concentration, However, the optical performance does not change with the concentration of thiol.According to the experimental results of solid state nuclear magnetic resonance, it is speculated that the thiol molecule may partially replace the n-trioctylphosphine oxide ligand in the quantum dot system, Stabilize the quantum dot system, play a protective role in the modification of quantum dots, thereby improving the optical properties of quantum dots.