Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils

Abstract

Graphene has been attracting great interest because of its distinctive band structure and physical properties. Today, graphene is limited to small sizes since it is produced mostly by exfoliating graphite. We grew large area graphene films of the order of centimeters on copper substrates by chemical vapor deposition using methane. The films are predominantly single layer graphene with a small percentage, < 5%, of the area having few layers, and are continuous across copper surface steps and grain boundaries. The low solubility of carbon in copper appears to help make this growth process self-limiting. Graphene film transfer processes to arbitrary substrates were also developed, and top gated field effect transistors fabricated on Si/SiO2 substrates showed electron mobilities as high as 4300 cm2V-1s-1 at room temperature.