Graphene synthesis by C implantation into Cu foils

Cu foils of 2 × 2 cm² have been implanted with 70 keV C^- ions to nominal fluences of (2-10) × 10¹⁵cm ^-2 at room temperature (RT) and subsequently annealed at 900-1100 C for 15 min, before being cooled to RT to form graphene layers on the Cu surfaces. Analyses with Raman spectroscopy and atomic force microscopy demonstrate that a continuous film of bi-layer graphene (BG) is produced for implant fluences as low as 2 × 10¹⁵ cm^-2, much less than the carbon content of the BG films. This suggests that the implanted carbon facilitates the nucleation and growth of graphene, with additional carbon supplied by the Cu substrate (0.515 ppm carbon content). No graphene was observed on unimplanted Cu foils subjected to the same thermal treatment. This implantation method provides a novel technique for the selective growth of graphene on Cu surfaces.