About this Journal Submit a Manuscript Table of Contents
Journal of Nanomaterials
Volume 2013 (2013), Article ID 127690, 7 pages
http://dx.doi.org/10.1155/2013/127690
Research Article

Classic and Quantum Capacitances in Bernal Bilayer and Trilayer Graphene Field Effect Transistor

1The TEPS Research Group, College of Engineering and Science, Footscray Park Campus, Victoria University, Melbourne, VIC 3011, Australia
2Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, VIC 3800, Australia

Received 9 November 2012; Accepted 26 March 2013

Academic Editor: Nadya Mason

Copyright © 2013 Hatef Sadeghi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Our focus in this study is on characterizing the capacitance voltage (C-V) behavior of Bernal stacking bilayer graphene (BG) and trilayer graphene (TG) as the channel of FET devices. The analytical models of quantum capacitance (QC) of BG and TG are presented. Although QC is smaller than the classic capacitance in conventional devices, its contribution to the total metal oxide semiconductor capacitor in graphene-based FET devices becomes significant in the nanoscale. Our calculation shows that QC increases with gate voltage in both BG and TG and decreases with temperature with some fluctuations. However, in bilayer graphene the fluctuation is higher due to its tunable band structure with external electric fields. In similar temperature and size, QC in metal oxide BG is higher than metal oxide TG configuration. Moreover, in both BG and TG, total capacitance is more affected by classic capacitance as the distance between gate electrode and channel increases. However, QC is more dominant when the channel becomes thinner into the nanoscale, and therefore we mostly deal with quantum capacitance in top gate in contrast with bottom gate that the classic capacitance is dominant.