Potential barrier of graphene edges

We calculated row resolved density of states, charge distribution and work function of graphene's zigzag and armchair edge (either clean or terminated alternatively with H, O, or OH group). The zigzag edge saturated via OH group has the lowest work function of 3.76 eV, while the zigzag edge terminated via O has the highest work function of 7.74 eV. The angle-dependent potential barrier on the edge is fitted to a multipole model and is explained by the charge distribution. VC 2011 American Institute of Physics. [doi: 10.1063/1.3587186]