Broadband full-spectrum Raman excitation mapping reveals intricate optoelectronic-vibrational resonance structure of chirality pure single walled carbon nanotube
Paul Finnie, Jeffrey Fagan, Jianying Ouyang
The Raman excitation spectra of chirality pure (6,5), (7,5) and (8,3) single walled carbon nanotubes (SWCNTs) are explored for homogenous solid film samples over broad excitation energy scattering energy ranges using a rapid and relatively simple full spectrum Raman excitation mapping technique. Identification of variation in scattering intensity with sample type and phonon energy related to different vibrational bands is clearly realized. Excitation profiles are found to vary strongly for different phonon modes, with some, such as the M and iTOLA modes, having quite sharp resonance profiles. Conventional fixed wavelength Raman spectroscopy can miss these effects on the scattering intensities entirely due to the significant intensity changes observed for small variations in excitation wavelength. Peak intensities for phonon modes traceable to a pristine carbon lattice forming a SWCNT sidewall were greater for high crystallinity materials. In the case of highly defective SWCNTs, the scattering intensity of the defect-related D band tracks the G band well. It is shown that this approach can make resonance Raman scattering intensity measurements more rigorous and quantitative, by taking intensity variations with laser wavelength into account.
, Fagan, J.
and Ouyang, J.
Broadband full-spectrum Raman excitation mapping reveals intricate optoelectronic-vibrational resonance structure of chirality pure single walled carbon nanotube, ACS Nano, [online], https://doi.org/10.1021/acsnano.2c10524, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935703
(Accessed June 7, 2023)