Optical transition energies () of each () SWNT plotted versus the respective RBM frequencies (), known as the Kataura plot [39]. The optical transition energies of semiconducting (circles) and metallic (stars) SWNTs are shown. Up triangles represent RBM results obtained from resonance Raman spectroscopy, taken from SWNTs deposited on crystalline miscut quartz [23]. The -axis for these up triangles coordinates is chosen by considering resonance at . The -axis is chosen by considering a correspondence between and : (a) the standard relation [40], and from (1); (b) Equation (2) with nm−2 and a 100 meV downshift in with respect to the values in (a) (adapted from [41]).
