Synthesis of Homogenous Bilayer Graphene on Industrial Cu Foil

We synthesize the homogenous graphene films on cheap industrial Cu foils using low pressure chemical vapor deposition. The quality and the number of layers of graphene are characterized by Raman spectra. Through carefully tuning the growth parameters, we find that the growth temperature, hydrocarbon concentration and the growth time can substantially affect the growth of high-quality graphene. Both single and bilayer large size homogenous graphenes have been synthesized in optimized growth conditions. The growth of graphene on Cu surface is found to be self ceasing in the bilayer graphene process with the low solubility of carbon in Cu. Furthermore, we have optimized the transfer process, and clear graphene films almost free from impurity are suc- cessfully transferred onto Si/SiO2 substrates. The field effect transistors of bilayer graphene are fabricated, which demonstrates a maximum hole （electron） mobility of 4300 cm^2 V- l s-1 （1920 cm^2 V^-1 s^-1） at room temperature.