Atomistic quantum transport modeling of metal-graphene nanoribbon heterojunctions

TL;DR

This paper models quantum transport in metal-graphene nanoribbon heterojunctions using atomistic self-consistent Schrödinger/Poisson calculations, revealing how interface chemistry and electrostatics affect conductance and doping.

Contribution

It provides a detailed atomistic simulation approach to understand the influence of interface bonding and electrostatics on transport in metal-graphene nanoribbon heterojunctions.

Findings

Band-bending and doping significantly affect conductance.

High work function metals promote p-type conduction.

Contact resistance varies with electrode material.

Abstract

We calculate quantum transport for metal-graphene nanoribbon heterojunctions within the atomistic self-consistent Schr\"odinger/Poisson scheme. Attention is paid on both the chemical aspects of the interface bonding as well the one-dimensional electrostatics along the ribbon length. Band-bending and doping effects strongly influence the transport properties, giving rise to conductance asymmetries and a selective suppression of the subband formation. Junction electrostatics and p-type characteristics drive the conduction mechanism in the case of high work function Au, Pd and Pt electrodes, while contact resistance becomes dominant in the case of Al.