Mott and Wiedemann Franz Law for Monolayer Graphene for Different Scattering Mechanisms

TL;DR

This paper analyzes the thermoelectric properties of monolayer graphene under various scattering mechanisms, confirming the validity of Mott and Wiedemann-Franz laws at low temperatures and exploring deviations at higher temperatures.

Contribution

It provides analytical and numerical evaluations of thermoelectric coefficients in graphene, highlighting the effects of different scattering mechanisms and temperature ranges.

Findings

Thermoelectric coefficients obey Mott and Wiedemann-Franz laws at low temperatures.

Deviations from these laws occur at higher temperatures.

Analytical and numerical results are consistent at low temperatures.

Abstract

In this study, we conducted a comprehensive review and analysis of the thermoelectric responses exhibited by monolayer pristine graphene in response to temperature variations. Employing the Boltzmann transport theory, we rigorously examined and evaluated various thermoelectric coefficients, with particular emphasis on elucidating their behavior under different scattering mechanisms. We derived the analytical expressions for electrical conductivity, thermopower, and thermal conductivity at low temperatures by Sommerfeld expansion of the Fermi integral. We demonstrated that our numerically obtained values are consistent with the analytical calculations at low temperatures and hence obeying Mott and Wiedeman Franz law. However, the deviation was observed at higher temperatures. Furthermore, we performed theoretical calculations of chemical potential at both low and high temperatures and compared them with our numerically evaluated results at all temperatures. Through extensive calculations and meticulous evaluation, our study contributes to a deeper understanding of the intricate thermoelectric properties inherent in monolayer pristine graphene.