Graphene field-effect transistor application-electric band structure of graphene in transistor structure extracted from quantum capacitance

Recently, various two-dimensional (2D) materials, such as graphene, transition metal dichalcogenides and so on, have attracted much attention in electron device research. The most important characteristic of graphene is its highest mobility of all semiconductor channels at room temperature. However, it is obvious that more than a good mobility characteristic is required to realize the field effect transistor (FET), and intense arguments from various points of view are necessary. In this paper, the issues with Si-metal oxide semiconductor FETs (Si-MOSFET) and the advantage of 2D materials are discussed. The present state of graphene FETs with respect to gate stack formation and band gap engineering is reported. Moreover, based on the density of states (DOS) of graphene extracted using the quantum capacitance (CQ) measurement, it is shown that the electric band structure of graphene in contact with gate insulators or metal electrode deviates from its intrinsic band structure.