Surface potentials and layer charge distributions in few-layer graphene films
Datta, S. and A. T. Charlie Johnson
Electrostatic Force Microscopy (EFM) reveals that the surface potential of graphene varies with the number of carbon layers. We find quantitative agreement with a non-linear Thomas-Fermi theory of screening by massless carriers. Proper understanding of such screening is critical to the design of functional graphene electronic devices. Graphene is thus not a single material, but rather a family of materials whose properties may be tuned by thickness.