Hu Yuecong, Chen Shaochuang, Cong Xin, Sun Sida, Wu Jiang-Bin, Zhang Daqi, Yang Feng, Yang Juan, Tan Ping-Heng, Li Yan
Beijing National Laboratory for Molecular Sciences, Key Laboratory for the Physics and Chemistry of Nanodevices, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
J Phys Chem Lett. 2020 Dec 17;11(24):10497-10503. doi: 10.1021/acs.jpclett.0c03320. Epub 2020 Dec 7.
The electronic Raman scattering (ERS) features of single-walled carbon nanotubes (SWNTs) can reveal a wealth of information about their electronic structures. Previously, the ERS processes have been exclusively reported in metallic SWNTs (M-SWNTs) and attributed to the inelastic scattering of photoexcited excitons by a continuum of low-energy electron-hole pairs near the Fermi level. Therefore, the ERS features have been thought to appear exclusively in M-SWNTs but not in semiconducting SWNTs (S-SWNTs), which are more desired in many application fields such as nanoelectronics and bioimaging. In this work, the experimental observation of the ERS features in suspended S-SWNTs is reported, the processes of which are accomplished via the available high-energy electron-hole pairs. The excitonic transition energies with an uncertainty in the order of ±1 meV can be directly obtained via the ERS spectra, compared to a typical uncertainty of ±10 meV in conventional electronic spectroscopies. The ERS features can facilitate further systematic studies on the properties of SWNT, both metallic and semiconducting, with defined chirality.
单壁碳纳米管（SWNTs）的电子拉曼散射（ERS）特性能够揭示有关其电子结构的大量信息。此前，ERS过程仅在金属性单壁碳纳米管（M-SWNTs）中被报道过，并且被归因于费米能级附近连续的低能电子-空穴对使光激发激子发生非弹性散射。因此，ERS特性一直被认为仅出现在M-SWNTs中，而不出现在半导体性单壁碳纳米管（S-SWNTs）中，然而在许多应用领域（如纳米电子学和生物成像）中，S-SWNTs更受青睐。在这项工作中，报道了在悬浮的S-SWNTs中对ERS特性的实验观测，其过程是通过可用的高能电子-空穴对来完成的。与传统电子光谱中典型的±10 meV的不确定性相比，通过ERS光谱可以直接获得不确定性在±1 meV量级的激子跃迁能量。ERS特性有助于对具有确定手性的金属性和半导体性SWNT的性质进行进一步的系统研究。
