The Resonance Structure of Raman Scattering for Emitted and Absorbed Phonons in Pure Carbon Nanotube Films

Published

November 14, 2025

Author(s)

Jeffrey Fagan, Paul Finnie, Jianying Ouyang, Adam Wind, Pavel Shapturenka

Abstract

Chirality pure single-wall carbon nanotubes (SWCNTs) are ideal samples for resonant Raman scattering (RS) as they have molecule-like optical transitions and strong Raman scatterers , having diameter and chirality specific resonances in the visible and in the near-infrared. Recently, it has become possible to rapidly obtain broadband maps of many vibrational modes of SWCNTs and their excitation resonances. Here, we use a full spectrum Raman excitation mapping technique to obtain experimental Raman excitation maps for several species of SWCNT [(7,6), (7,5) and (6,5)] purified by two different methods, mapping both phonon emission (Stokes) RS and phonon absorption (anti-Stokes) RS. These experimental maps show intricate patterns which match well with some of the predictions of quantum models of RS. All RS bands necessarily have different excitation structure, but Stokes and anti-Stokes pairs are symmetrical. Maps overall show a butterfly-shaped pattern interpreted in terms of the excitonic resonances with incident photons and scattered photons. Temperature activates anti-Stokes scattering and this is critical to interpreting that half of the map. Nanotubes are robust, and Stokes/anti-Stokes maps can be obtained over orders of magnitude in laser power, which is a critical variable. At their strongest, near the incident photon exciton resonance, SWCNT G bands are enhanced ≈3000× over graphite G bands. The 2D band is enhanced by similar factors but has a different resonant profile.

Citation

ACS Nano

Volume

19

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acsnano.5c12607

Local Download

Keywords

Raman scattering, SWCNT, metrology, carbon nanotube, Stokes, Anti-Stokes

Citation

Fagan, J. , Finnie, P. , Ouyang, J. , Wind, A. and Shapturenka, P. (2025), The Resonance Structure of Raman Scattering for Emitted and Absorbed Phonons in Pure Carbon Nanotube Films, ACS Nano, [online], https://doi.org/10.1021/acsnano.5c12607, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960299 (Accessed April 9, 2026)