Enhanced thermoelectric figure of merit in edge disordered zigzag graphene nanoribbons

TL;DR

This study demonstrates that edge disorder in zigzag graphene nanoribbons significantly suppresses phonon thermal transport while preserving electronic conduction, leading to high thermoelectric efficiency.

Contribution

It introduces a detailed analysis of edge disorder effects on thermoelectric properties of zigzag graphene nanoribbons using nonequilibrium Green functions.

Findings

Phonon thermal transport is dramatically reduced by edge disorder.

Electronic conduction remains weakly affected by edge disorder.

High thermoelectric figure of merit (ZT) values are achieved.

Abstract

We investigate electron and phonon transport through edge disordered zigzag graphene nanoribbons based on the same methodological tool of nonequilibrium Green functions. We show that edge disorder dramatically reduces phonon thermal transport while being only weakly detrimental to electronic conduction. The behavior of the electronic and phononic elastic mean free paths points to the possibility of realizing an electron-crystal coexisting with a phonon-glass. The calculated thermoelectric figure of merit (ZT) values qualify zigzag graphene nanoribbons as a very promising material for thermoelectric applications.