Linewidth of the Raman features of individual single-wall carbon nanotubes

In this work we analyze the room-temperature linewidth for several Raman features (i.e., the radial breathing mode, the G band, the D band, and the $G^{\prime }$ band) observed for individual isolated single-wall carbon nanotubes (SWNTs). Temperature-dependent measurements on SWNT bundles and isolated SWNTs show that anharmonic effects are not important for linewidth broadening at room temperature. Measurements on a large number of samples (170 isolated SWNTs) allow us to filter out the effect from extrinsic SWNT properties (e.g., defects, tube deformations, substrate roughness) and to obtain information about intrinsic properties related to phonon and electron dispersion relations, curvature and Breit-Wigner-Fano effects, single- vs double-resonance Raman scattering processes, and the resonance condition itself through a linewidth analysis. We also use observations at the single-nanotube level to understand linewidth effects in SWNT bundles.