%0 Journal Article
%T Substrate effects on quasiparticles and excitons in graphene nanoflakes
%A W. Sheng
%A M. Sun
%A A. Zhou
%A S. J. Xu
%J Physics
%D 2013
%I arXiv
%R 10.1063/1.4823829
%X The effects of substrate on electronic and optical properties of triangular and hexagonal graphene nanoflakes with armchair edges are investigated by using a configuration interaction approach beyond double excitation scheme. The quasiparticle correction to the energy gap and exciton binding energy are found to be dominated by the long-range Coulomb interactions and exhibit similar dependence on the dielectric constant of the substrate, which leads to a cancellation of their contributions to the optical gap. As a result, the optical gaps are shown to be insensitive to the dielectric environment and unexpectedly close to the single-particle gaps.
%U http://arxiv.org/abs/1308.4790v1