Semianalytical quantum model for graphene field-effect transistors

TL;DR

This paper presents a semianalytical quantum model for monolayer graphene FETs in the ballistic limit, accurately capturing quantum tunneling and density of states effects, validated against NEGF simulations.

Contribution

The paper introduces a novel semianalytical model for graphene FETs that accounts for quantum tunneling and density of states effects, validated against NEGF methods.

Findings

Model accurately predicts device behavior in quasi-saturation and negative differential resistance regions.

Captures effects of finite density of states and quantum tunneling.

Provides results comparable to self-consistent NEGF simulations.

Abstract

We develop a semianalytical model for monolayer graphene field-effect transistors in the ballistic limit. Two types of devices are considered: in the first device, the source and drain regions are doped by charge transfer with Schottky contacts, while, in the second device, the source and drain regions are doped electrostatically by a back gate. The model captures two important effects that influence the operation of both devices: (i) the finite density of states in the source and drain regions, which limits the number of states available for transport and can be responsible for negative output differential resistance effects, and (ii) quantum tunneling across the potential steps at the source-channel and drain-channel interfaces. By comparison with a self-consistent non-equilibrium Green's function solver, we show that our model provides very accurate results for both types of devices, in the bias region of quasi-saturation as well as in that of negative differential resistance.