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在水相中制备了半导体CdTe纳米晶,核-壳型CdTe/CdS和CdTe/ZnS纳米晶(即量子点;QDs).利用扫描隧道显微镜(STM)和荧光光谱(FS)对合成的纳米晶量子点进行了研究,并且根据FS的数据进行了量子效率的计算.STM的结果表明合成的量子点直径约为3nm并且分布良好.为了提高量子效率,对Cd2+浓度和Cd2+∶S2-比例等反应条件进行了研究,结果表明随着回流时间的增加,核-壳型量子点CdTe/CdS的量子效率总体上呈下降趋势.CdTe/CdS在pH8.5,Cd2+∶S2-=10∶1(摩尔比)时可获得80.0%的最大量子效率.同时制备了核-壳型量子点CdTe/ZnS,其最大发射波长由551nm(CdTe)红移到635nm(CdTe/ZnS)表明量子点的尺寸在增长,但是量子效率下降到14.4%.当前研究的量子点可适用于生物标记,生物成像,以及基于共振能量转移的生物传感研究.
Semiconductor CdTe nanocrystals, core-shell CdTe / CdS and CdTe / ZnS nanocrystals (QDs) were prepared in the aqueous phase.The synthesized nanocrystals were characterized by scanning tunneling microscopy (STM) and fluorescence spectroscopy (FS) Quantum dots were studied, and the quantum efficiency was calculated according to the FS data.The results of STM show that the synthesized quantum dots are about 3nm in diameter and well distributed.In order to improve the quantum efficiency, the reaction of Cd2 + concentration and Cd2 +: S2-ratio The results show that with the increase of reflux time, the quantum efficiency of CdTe / CdS core-shell quantum dots is generally on the downward trend.CdTe / CdS at pH8.5, Cd2 +: S2- = 10: 1 The maximum quantum efficiency of 80.0% can be obtained.While the core-shell quantum dots CdTe / ZnS have been prepared, their maximum emission wavelength shifts from 551nm (CdTe) to 635nm (CdTe / ZnS) , But the quantum efficiency dropped to 14.4%. The quantum dots currently studied can be applied to biomarkers, bioimaging, and biosensing studies based on resonance energy transfer.