|Table 1: Assignments and frequency behavior for the Raman modes from sp2 carbon materials .|
(1)Usually the respective graphene phonon branch labels the Raman peaks. When other names are given in the literature, the respective phonon branch appears between parentheses.|
(2)The frequencies quoted in the table are observed at eV.
(3)The notation for resonances is as follows: SR: single resonance, 1-phonon Raman allowed; DR2: double resonance, 2-phonon Raman allowed; DRd1: double resonance Raman activated by disorder, 1 phonon; DRd2: double resonance Raman activated by disorder, 2 phonons.
(4)The change of phonon frequency in cm−1 obtained by changing the laser excitation energy by 1 eV.
(5)Intra-V: intravalley scattering; Inter-V: intervalley scattering.
(6)The radial breathing mode (RBM) only occurs for carbon nanotubes.
(7)The iTO and LO phonons are degenerated at the Γ point for graphene. For nanoribbons and SWNTs, the G band splits into several peaks due to symmetry, and differs for metallic and semiconducting nanotubes. The G band frequency depends strongly on doping and strain.
(8)There is another assignment of 2iTO ( ~ 0 near K) with .
(9)Some groups use the nomenclature “2D band” for the G′ band.
(10)This combination mode consists of intra-valley + inter-valley scattering, and thus, the elastic scattering process also exists for some combination modes.