Increase in off current of bilayer graphene by band gap engineering caused by external electrostatic field

石墨烯基器件是未来高速场效应晶体管（fet）的有希望的候选器件。为了充分利用石墨烯通道的高性能，实现石墨烯与金属之间的低接触电阻率（ρC）是最重要的。这项工作的目的是确定石墨烯/金属接触处的电流流动路径。实验结果表明，ρC不以A为特征，而以w为特征。由于金属的电阻率远小于石墨烯的电阻率，因此可以认为电流优先在金属膜中流动，并在接触边缘从金属进入石墨烯。

Graphene-based devices are promising candidates for future high-speed filed effect transistors (FETs). To make the best use of the high performance of graphene channel, achieving the lowcontact resistivity (ρC) between graphene and metal is most important. The purpose of this work is to determine the current flow path at the graphene/metal contact. The experimental results indicate that ρC is not characterized by A but by W. Since the resistivity of the metal is much smaller than the graphene resistivity, it can be considered that the current flows preferentially in the metal film, and enters from the metal to graphene at the edge of the contact.