Engineering Enhanced Thermoelectric Properties in Zigzag Graphene Nanoribbons

TL;DR

This paper presents a theoretical study on improving thermoelectric efficiency in zigzag graphene nanoribbons through structural engineering, including defects and impurities, using quantum simulations.

Contribution

It introduces a series of engineering modifications to enhance thermoelectric performance of zigzag graphene nanoribbons, which initially have poor efficiency.

Findings

Performance significantly improved after engineering modifications

Quantum simulations confirm enhanced thermoelectric properties

Design strategies could inform high-efficiency graphene-based thermoelectric devices

Abstract

We theoretically investigate the thermoelectric properties of zigzag graphene nanoribbons in the presence of extended line defects, substrate impurities and edge roughness along the nanoribbon's length. A nearest-neighbor tight-binding model for the electronic structure and a fourth nearest- neighbor force constant model for the phonon bandstructure are used. For transport we employ quantum mechanical non-equilibrium Green's function simulations. Starting from the pristine zigzag nanoribbon structure that exhibits very poor thermoelectric performance, we demonstrate how after a series of engineering design steps the performance can be largely enhanced. Our results could be useful in the design of highly efficient nanostructured graphene nanoribbon based thermoelectric devices.