Gate‐Tunable Potential Barrier on Dual‐Gate Graphene Transistor with Fluorocarbon Thin Film

Abstract This article reports on the charge transport characteristics across the potential barrier generated by a local dual‐gate modulation at the surface of p‐doped graphene via surface contact on a fluorocarbon (CF) thin film. Owing to simple physical contact, the strong electron affinity of the fluorine atoms in CF stably increases the hole density of graphene, which leads to a massive p‐doping effect in graphene. Then, potential barrier height can be generated and modulated across the channel by forming a local dual‐gate device structure. Different gate biases in dual‐gate operation can split electrical characteristics of a single graphene into highly conductive region and region of sparse charge density, creating large chemical potential difference at the boundary between the two which determines the value of barrier height. Moreover, the device characteristics follow a simple model of the metal–semiconductor junction well in addition to the effect of charge concentration discrepancy in graphene. These results reveal that it is possible to create an ideal and controllable potential barrier composed of a single material using the highly doped graphene with the local dual‐gate structure.