Figure 2: Radial breathing mode (RBM) regions of resonant Raman scattering spectra at three excitation energies.

(a) 2.33 eV (532 nm) is mainly resonant with met-SWNTs (blue shaded) in the range of 180–285 cm−1, (b) 1.96 eV (633 nm) is resonant with met-SWNTs and sc-SWNTs (red shaded) in ~1:1 ratio, (c) 1.58 eV (785 nm) is resonant with sc-SWNTs. The peak intensities of the SWNTs with the diameter distribution between 0.88 and 1 nm were enhanced after sorting. In each spectrum, the upper RBM profile (black triangle) and the lower profile (black sphere) represent before and after sorting, respectively. The assignments of peaks can be found in Supplementary Tables S3-S5.