Electronic, phononic, and thermoelectric properties of graphyne sheets

Electron, phonon, and thermoelectric transport properties of α-, β-, γ-, and 6,6,12-graphyne sheets are compared and contrasted with those of graphene. α-, β-, and 6,6,12-graphynes, with direction dependent Dirac dispersions, have higher electronic transmittance than graphene. γ-graphyne also attains better electrical conduction than graphene except at its band gap. Vibrationally, graphene conducts heat much more efficiently than graphynes, a behavior beyond an atomic density differences explanation. Seebeck coefficients of the considered Dirac materials are similar but thermoelectric power factors decrease with increasing effective speeds of light. γ-graphyne yields the highest thermoelectric efficiency with a thermoelectric figure of merit as high as ZT-=-0.45, almost an order of magnitude higher than that of graphene.Scientific and Technological Research Council of Turkey (113F096-BIDEB/113C032); Anadolu University; Turkish Academy of Sciences (TUBA-GEBIP); Science Academy, Turkey under BAGEP progra