A Current–Voltage Model for Graphene Electrolyte-Gated Field-Effect Transistors

Abstract

This paper presents a model for graphene electrolyte-gated field-effect transistors (EGFETs) that incorporates the effects of the graphene-electrolyte interface and quantum capacitance of graphene. The model is validated using experimental data collected from fabricated graphene EGFETs and is employed to extract device parameters such as mobility, minimum carrier concentration, interface capacitance, contact resistance, and effective charged impurity concentration. The proposed graphene EGFET model accurately determines a number of properties necessary for circuit design, such as current-voltage characteristics, transconductance, output resistance, and intrinsic gain. The model can also be used to optimize the design of EGFETs. For example, simulated and experimental results show that avoiding the practice of partial channel passivation enhances the transconductance of graphene EGFETs.