Disentangling Electronic and Phononic Thermal Transport Across 2D Interfaces

TL;DR

This paper proposes a theoretical method to distinguish electronic and phononic thermal conductance at 2D material interfaces, validated by simulations, revealing different transport behaviors and enabling experimental testing of the Wiedemann-Franz law.

Contribution

It introduces a novel approach to separate electronic and phononic contributions to thermal conductance at 2D interfaces, supported by Green's function and molecular dynamics simulations.

Findings

Metal-graphene interfaces are transparent for electrons and phonons.

Non-covalent graphene interfaces block electronic tunneling beyond two layers.

The approach enables experimental testing of the Wiedemann-Franz law.

Abstract

Electrical and thermal transport across material interfaces is key for 2D electronics in semiconductor technology, yet their relationship remains largely unknown. We report a theoretical proposal to separate electronic and phononic contributions to thermal conductance at 2D interfaces, which is validated by non-equilibrium Green's function calculations and molecular dynamics simulations for graphene-gold contacts. Our results reveal that while metal-graphene interfaces are transparent for both electrons and phonons, non-covalent graphene interfaces block electronic tunneling beyond two layers but not phonon transport. This suggests that the Wiedemann-Franz law can be experimentally tested by measuring transport across interfaces with varying graphene layers.