CdSe/CdS核壳纳米晶微波水热法一步合成与发光光谱分析

One-step Preparation of CdSe /CdS Core-shell Nanocrystals by Microwave Hydrothermal Method and Photoluminescence Spectra Analysis

采用微波水热法一步合成了核壳结构的CdSe/CdS纳米晶,讨论了巯基丙酸中S2-的释放过程对纳米晶生长的影响。XRD和Raman光谱结果表明,140℃合成温度下获得了CdSe/CdS核壳结构的纳米晶。FTIR光谱结果表明,巯基丙酸随时间的分解有助于CdS壳层的形成。PL光谱呈现出CdSe纳米晶的带间发射和缺陷发射,随着核壳结构的形成,CdSe纳米晶的表面缺陷被抑制,相关的荧光发射减弱。

CdSe /CdS core-shell nanocrystals were one-step prepared by microwave-hydrothermal method.The growth mechanism of nanoparticles was discussed and attributed to the sulfur release process from mercaptopropionic acid.The results from XRD and Raman spectra suggested that the core-shell CdSe /CdS nanocrystals were obtained under the reaction temperature of 140 ℃.FTIR spectra were in situ monitored for the decomposition of mercaptopropionic acid upon reaction time,which contributed to the formation of CdS shells.The band-related and trap states fluorescent emission from nanocrystals were both observed in PL spectra.The increased band related emission intensity further verified the formation of core /shell structure of CdSe nanocrystals.