A dilute Cu(Ni) alloy for synthesis of large-area Bernal satcked bilayer graphene using atmospheric pressure chemical vapour deposition

摘要

A bilayer graphene film obtained on copper (Cu) foil is known to have a significant fraction ofnon-Bernal (AB) stacking and on copper/nickel (Cu/Ni) thin films is known to grow over alarge-area with AB stacking. In this study, annealed Cu foils for graphene growth were doped withsmall concentrations of Ni to obtain dilute Cu(Ni) alloys in which the hydrocarbon decompositionrate of Cu will be enhanced by Ni during synthesis of large-area AB-stacked bilayer grapheneusing atmospheric pressure chemical vapour deposition. The Ni doped concentration and the Nihomogeneous distribution in Cu foil were confirmed with inductively coupled plasma opticalemission spectrometry and proton-induced X-ray emission. An electron backscatter diffractionmap showed that Cu foils have a single (001) surface orientation which leads to a uniform growthrate on Cu surface in early stages of graphene growth and also leads to a uniform Ni surfaceconcentration distribution through segregation kinetics. The increase in Ni surface concentrationin foils was investigated with time-of-flight secondary ion mass spectrometry. The quality of graphene,the number of graphene layers, and the layers stacking order in synthesized bilayer graphenefilms were confirmed by Raman and electron diffraction measurements. A four point probe stationwas used to measure the sheet resistance of graphene films. As compared to Cu foil, the prepareddilute Cu(Ni) alloy demonstrated the good capability of growing large-area AB-stacked bilayergraphene film by increasing Ni content in Cu surface layer.