Effects of methane flux on structural and transport properties of CVD-grown graphene films

Large area, single-layer graphene films were synthesized on copper foils by chemical vapor deposition. We have investigated the effects of methane flux on structural and transport properties of graphene. Raman spectra and electrical results reveal that methane flux has almost no influence on the thickness of graphene, but clearly influences the structural defects of graphene. In addition, graphene field effect transistors with a gate length of 10 μm were fabricated, exhibiting obvious field effects and p-type characteristics.

► The CVD-growth and transfer of four-inch, single-layer graphene films have been demonstrated.
► Raman spectra and electrical results reveal that methane flux has almost no influence on the thickness of graphene, but has an obvious influence on surface structure defects and transport properties of graphene.
► Both G and 2D peaks of Raman spectra shift to low wavenumbers with increasing methane flux.
► Graphene field effect transistors exhibit obvious field effects and p-type characteristics.