Wafer-scale synthesis and transfer of monolayer graphene

Wafer-scale monolayer graphene film was synthesized on Cu foils by chemical vapor deposition in a 3-in thermal furnace. Graphene film was transferred to the surface of SiO₂ (300 nm)/Si substrates using a polymer-assisted method. Hall bar structures were fabricated by lithography and E-beam deposition for the electrical property measurement. Perfect symmetrical ohmic resistance distribution was achieved. The longitudinal resistance was measured at different temperatures, and it showed negative differential resistance behavior with temperatures below 88K. Wafer scale graphene were also transferred to a flexible poly (ethylene terephthalate) (PET) substrate for flexible electronics application. The transmittance of the monolayer graphene at 550 nm was measured to be 95.6% and the sheet resistance was 5.6kΩ/□.