Excitonic properties of hydrogen saturation-edged armchair graphene nanoribbons.

First-principle density functional theory calculations with quasiparticle corrections and many body effects are performed to study the electronic and optical properties of armchair graphene nanoribbons (AGNRs) with variant edges saturated by hydrogen atoms. The "effective width" method associated with the reported AGNR family effect is introduced to understand the electronic structures. The method is further confirmed by analyses of the optical transition spectra and the exciton wavefunctions. The optical properties, including the optical transition spectra, exciton binding energies and the distribution of exciton wavefunctions, can be tuned with the hydrogen saturation edge, thus providing an effective way to control the features of the AGNRs.