▎ 摘　　要

By solving the Bethe-Salpeter equation within the Hartree-Fock formalism, we study the optical spectra, optical gap, quasi-particle gap, exciton binding energy, and wave function of a closed-shell graphene system. With the excitonic effects fully taken into account, we find that all peaks of optical spectrum are blueshifted to higher photon energy with either the enhancement of the long-range Coulomb interactions or the suppression of the short-range Coulomb interactions but are redshifted to lower photon energy due to the increased size and decreased confinement. Remarkably, the region of a much higher relative probability for an electron resides mainly around the geometrical center of the structure, whereas the hole strongly localizes in the peripheral region of the geometric center. Our results are found to agree well with both recent experimental and theoretical works. Published by AIP Publishing.