高发光效率CdTe@SiO2量子点的制备

Preparation of CdTe@SiO2 Quantum Dots with High Luminescence Efficiency

SiO2包覆CdTe量子点过程中通常导致荧光效率大幅降低,严重影响后续分析应用的灵敏度。为制备高发光效率的CdTe@SiO2量子点,基于吐温80/环已烷/1-已醇/CdTe量子点反相微乳液体系,考察了TEOS和氨水的用量、反应时间及助表面活性剂种类对制备CdTe@SiO2的影响。利用透射电子显微镜、分子荧光光谱仪以及紫外可见分光光谱仪对制备的CdTe@SiO2形貌和性能进行了表征。结果表明,CdTe@SiO2的最佳制备条件是TEOS和氨水的用量均为120μL,反应时间为24 h,助表面活性剂为1-己醇。CdTe@SiO2量子产率为27.9%,相对包覆前,量子产率保持率为84.5%。

The fluorescence efficiency of CdTe quantum dots often has a dramatic decrease after being coated by SiO2,which significantly influenced the sensitivity of subsequent analysis application.Based on the reverse microemulsion system of Tween 80/cyclohexane/1-hexanol/CdTe QDs,the effects of the amounts of TEOS and ammonia,the kinds of cosurfactants and the reaction time on fluorescence intensity of the CdTe@SiO2 were investigated.Obtained CdTe@SiO2 QDs were characterized by means of transmission electron microscope,molecular fluorescence spectrophotometer and ultraviolet-visible spectrometer.The results demonstrate that the optimal conditions were 120μL of ammonia and TEOS,n-hexanol as cosurfactant,and reaction time was 24 h.The fluorescence quantum yield of the CdTe@SiO2 was 27.9%,and 84.5%of the original quantum yield of CdTe was kept after being coated.