Fig. 6. Properties of SWNTs.

a Schematic illustrating the roll-up vector and chiral angle combinations informing SWNT chirality. b Band diagram illustrating the electronic transitions leading to SWNT fluorescence. Electrons are excited from v₂ into c₂, where they relax into c₁. Upon recombination with a hole in v₁, photons are emitted with an energy corresponding to the bandgap. a, b Reprinted from ref. ⁹⁸ with permission. c Excitation-emission maps of individually dispersed SWNTS, with excitation wavelengths ranging between 500–900 nm and emission wavelength of 800–1600 nm. Reprinted from ref. ⁹⁷ with permission.