Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

Mehdi Saeidmanesh,Elnaz Akbari,Wong King Kiat,Mohammad Taghi Ahmadi,Meisam Rahmani,Hediyeh Karimi,Rubiyah Yusof

doi:10.1155/2013/836315

Abstract

Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presented, and also based on the analytical model a numerical solution is reported. We begin by modeling the DOS, followed by carrier concentration as a functionVin degenerate and nondegenerate regimes. To further confirm this viewpoint, the presented analytical model is compared with experimental data, and acceptable agreement is reported.

Highlights

Graphene, an atomic layer of carbon atoms arranged in a two-dimensional (2D) honeycomb lattice, has drawn researchers’ attention due to its exceptional mechanical and electrical properties for new semiconductor materials and devices [1,2,3]
A bandgap in Bilayer graphene (BLG) can be created by applying a perpendicular electric field and incorporating the inversion symmetry breaking between double layers in the atomic structure
The focus of this paper is to model the quantum capacitance of bilayer graphene based electrolyte-gated bilayer graphene field-effect transistors (EGFETs)

Summary

Introduction

Graphene, an atomic layer of carbon atoms arranged in a two-dimensional (2D) honeycomb lattice, has drawn researchers’ attention due to its exceptional mechanical and electrical properties for new semiconductor materials and devices [1,2,3]. The focus of this paper is to model the quantum capacitance of bilayer graphene based EGFET To address this possibility, two interfacial capacitances which arise from the double layer formed by ions at the graphene ionic liquid interface and the quantum capacitance of graphene have a strong influence on the measurement of the total capacitance. The aim of this study is to evaluate the quantum capacitance of bilayer graphene sheet as a function of voltage and validate theoretical predictions with the experimental results [18]

Proposed Model

Conclusion