SymFET: A Proposed Symmetric Graphene Tunneling Field Effect Transistor

TL;DR

This paper presents an analytical model for the SymFET, a graphene-based tunneling FET, highlighting its temperature independence, high on/off ratio, and potential for high-speed and digital applications due to its symmetric bandstructure.

Contribution

The paper introduces a novel analytical model for SymFETs that captures their unique tunneling behavior and symmetry properties, enabling better design and understanding of graphene-based devices.

Findings

Current peaks at specific bias due to Dirac point alignment

Weak temperature dependence of SymFET current

High on/off ratio influenced by doping and coherence length

Abstract

In this work, an analytical model to calculate the channel potential and current-voltage characteristics in a Symmetric tunneling Field-Effect-Transistor (SymFET) is presented. The current in a SymFET flows by tunneling from an n-type graphene layer to a p-type graphene layer. A large current peak occurs when the Dirac points are aligned at a particular drain-to- source bias VDS . Our model shows that the current of the SymFET is very weakly dependent on temperature. The resonant current peak is controlled by chemical doping and applied gate bias. The on/off ratio increases with graphene coherence length and doping. The symmetric resonant peak is a good candidate for high-speed analog applications, and can enable digital logic similar to the BiSFET. Our analytical model also offers the benefit of permitting simple analysis of features such as the full-width-at-half-maximum (FWHM) of the resonant peak and higher order harmonics of the nonlinear current. The SymFET takes advantage of the perfect symmetry of the bandstructure of 2D graphene, a feature that is not present in conventional semiconductors.