Large-signal model of the bilayer graphene field-effect transistor targeting radio-frequency applications: theory versus experiment

TL;DR

This paper develops a comprehensive large-signal model for dual-gated bilayer graphene FETs, incorporating carrier transport, electrostatics, and contact effects, and validates it against experimental data for RF applications.

Contribution

It introduces a new large-signal model for bilayer graphene FETs that accounts for drift-diffusion transport, Schottky barriers, and device electrostatics, validated with experiments.

Findings

Model accurately predicts RF performance metrics.

Inclusion of Schottky barriers improves model realism.

Model matches experimental data across device parameters.

Abstract

Bilayer graphene is a promising material for radio-frequency transistors because its energy gap might result in a better current saturation than the monolayer graphene. Because the great deal of interest in this technology, especially for flexible radio-frequency applications, gaining control of it requires the formulation of appropriate models for the drain current, charge and capacitance. In this work we have developed them for a dual-gated bilayer graphene field-effect transistor. A drift-diffusion mechanism for the carrier transport has been considered coupled with an appropriate field-effect model taking into account the electronic properties of the bilayer graphene. Extrinsic resistances have been included considering the formation of a Schottky barrier at the metal-bilayer graphene interface. The proposed model has been benchmarked against experimental prototype transistors, discussing the main figures of merit targeting radio-frequency applications.