Spatial variation of wear and electrical properties across wrinkles in chemical vapour deposition graphene

Chemical vapour deposition (CVD) is an effective and simple method for production of large area graphene needed for technological applications. However, CVD graphene contains a network of out of plane deformations - graphene wrinkles. Using atomic force microscopy (AFM) based methods, we find a significant change of graphene wear and electrical properties across the wrinkles. It is shown that graphene tearing by an AFM tip starts exactly from the wrinkles. Kelvin probe force microscopy shows that the surface potential of graphene is inhomogeneous, with domains within closed wrinkles having the surface potential different from the surrounding graphene. Conductive AFM shows that the electrical current drops exactly along wrinkles. Therefore, wrinkles decrease wear resistivity of graphene, they act as potential barriers for charge carriers leading to their localization, and lead to charge carrier scattering and increased contact resistance.