Screening and Interlayer Coupling in Multilayer Graphene Field-Effect Transistors

With the motivation of improving the performance and reliability of aggressively scaled nanopatterned graphene field-effect transistors, we present the first systematic experimental study on charge and current distribution in multilayer graphene field-effect transistors. We find a very particular thickness dependence for I-on, I-off, and the I-on/I-off ratio and propose a resistor network model including screening and interlayer coupling to explain the experimental findings. In particular, our model does not invoke modification of the linear energy-band structure of graphene for the multilayer case. Noise reduction in nanoscale few-layer graphene transistors is experimentally demonstrated and can be understood within this model as well.