Theoretical investigation of quasiparticle band structures and optical spectra of large-diameter semiconducting single-walled carbon nanotubes

Using ab initio many-body perturbation theory (within GW approximation and Bethe-Salpeter equation), including electronic exchange, correlation, and electron-hole interaction effects, we study the optical properties of large-diameter semiconducting single-walled carbon nanotubes (SWCNTs). The calculated energies of the lowest two optically allowed transitions (E₁₁ and E₂₂) agree well with those deduced from experiments. The lowest optical allowed transition of these tubes is between the first two van Hove singularities on each side of the Fermi level, which is different from that of small-diameter tubes. The exciton binding energy for E₁₁ is calculated, which is consistent with that of the experiments.