研究了CdSe量子点膜的Raman光谱,发现CdSe量子点的横模(TO)振动活性较强,表面模(SO)、纵模(LO)振动不明显。比较了量子点、氧化三辛基膦及十六胺的Raman光谱,证明量子点表面大部分区域被十六胺及二辛胺修饰。在此基础上,对量子点膜的TO模振动及C-H弯曲振动峰进行了Raman成像分析,并与明场图像进行了对比,表明拉曼成像信号对量子点膜的表面变化非常敏感。
The Raman spectrum of CdSe quantum dots (QDs) film was investigated. The results showed that transverse optical(TO) mode of CdSe QDs was obvious. However, surface optical (SO) and longitudinal optical (LO) could not be seen from Raman spectrum. The Raman spectra of CdSe QDs, tri-n-octylphosphine oxide and hexadecylamine were compared. It was found that the Raman spectrum of surface reagents of CdSe QDs was similar to that of hexadecylamine, but different from that of tri-n-octylphosphine oxide, which proved that the surface of CdSe QDs were coated with hexadecylamine and dioetylamine. The Raman images with TO mode and C--H bending vibration were analyzed in comparison with bright image, whieh indicated that the signal of Raman imaging was sensitive to the change of QD surface.