@article{Vardeny2023, 
author = {Shai R. Vardeny and Alan Phillips and Kira A. Thurman and Z. Valy Vardeny and Jeffrey L. Blackburn},
title = {Amplitude-mode spectroscopy of chemically injected and photogenerated charge carriers in semiconducting single-walled carbon nanotubes},
year = {2023},
journal = {Nano Research},
volume = {16},
number = {4},
pages = {5619-5625},
keywords = {carbon nanotubes, doping, charge carriers, phonons, electron-phonon coupling},
url = {https://www.sciopen.com/article/10.1007/s12274-022-5080-1},
doi = {10.1007/s12274-022-5080-1},
abstract = {In one-dimensional semiconductors such as conjugated polymers and semiconducting single-walled carbon nanotubes (s-SWCNTs), injected charge carriers (electrons or holes) can have profound impacts on both electronic conductivity and optical spectra, even at low carrier densities. Understanding charge-related spectral features is a key fundamental challenge with important technological implications. Here, we employ a systematic suite of experimental and theoretical tools to understand the mid-infrared charge signatures of heavily p-type doped polymer-wrapped s-SWCNTs. Across a broad range of nanotube diameters, we find that hole charge carriers induce strong Fano anti-resonances in mid-infrared transmission spectra that correspond to defect-related (D-band) and in-plane tangential (G-band) Raman-active vibrational modes, along with anti-resonances arising from infrared (IR)-active polymer and SWCNT modes. We employ 13C isotope-labeled s-SWCNTs and a removable wrapping polymer to clarify the relative intensities, energies, and sources of all observed anti-resonances. Simulations performed with the “amplitude mode model” are used to quantitatively reproduce Raman spectra and also help to explain the outsized intensity of the D-band anti-resonance, relative to the G-band, observed for both moderately and degenerately doped s-SWCNTs. The results provide a framework for future studies of ground- and excited-state charge carriers in s-SWCNTs and a variety of low-dimensional materials.}
}