Graphyne May Outdo Graphene

Graphene may not be unique among two-dimensional materials in terms of its exceptionally high electronic conductivity and other outstanding electronic properties, according to a theoretical study. Daniel Malko, Andreas Görling, and coworkers at the University of Erlangen-Nürnberg, in Germany, report in Physical Review Letters that some electronic properties of graphyne, a family of atom-thin carbon films featuring conjugated combinations of C=C and C≡C bonds, may be superior to those of graphene (DOI: 10.1103/physrevlett.108.086804). Researchers have previously attributed graphene’s extreme charge-transport properties to its hexagonal carbon structure and the existence of Dirac cones, which are features on plots of graphene’s electronic band structure that describe the distribution of the material’s electron energy levels. The new study indicates that the band structures of some graphynes, even ones that lack hexagonal symmetry, are also characterized by Dirac cones. These results suggest “a wealth of 2-D materials with electronic properties that might be as amazing and promising as those of graphene is waiting to be synthesized and applied,” the researchers note.