▎ 摘　　要

We demonstrate a novel Janus-type mosaic graphene (J-MOG) for achieving a ubiquitous bandgap opening by asymmetrical modification with covalently bonded H, F, Cl, and Br on opposing sides of graphene sheet. The theoretical capacity of J-MOG is shown to break the pattern restrictions, giving a robust non-zero gap. Our approach provides an effective pathway for the bandgap engineering of graphene for various electronic applications. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793997]