Abstract
Single-layer graphene, a two-dimension carbon material which possesses high chemical stability, high carrier mobility, unique optical property, and a dimension with nano-scale level, is promising for the application in graphene-based devices. To partially replace the Si-based devices, it is requested that the fabrication process for the graphene-based device should be compatible with the technology used in present semiconductor industry. In this work, large-area single graphene was synthesized on Cu foil by low pressure chemical vapor deposition. The graphene films were transferred from Cu foil to polyethylene terephthalate(PET) using PMMA anisole solution for fabricating flexible transparent graphene-based field-effect transistors. The electropolish method was used to reduce the roughness of the Cu foil. Roughness of the Cu foil surface is an important factor that influences the morphology of graphene films on transferred substrate and affects electronic transport property of the graphene-based devices. The influences of the electropolish process on roughness of the transferred graphene were investigated by using Raman spectrum, scanning electron microscope, and optical microscope; and we found that the electropolish process improves the electronic transport property of the graphene-based devices. Carrier mobility of the graphene-based devices was increased 2-3 times when the electropolish process was adopted. Variations on the electronic transport property of the graphene-based devices before and after bending were tested and the results are discussed.