Heat transport across graphene/hexagonal-BN tilted grain boundaries from phase-field crystal model and molecular dynamics simulations

TL;DR

This study combines phase-field crystal modeling and molecular dynamics simulations to investigate heat transfer across graphene/h-BN grain boundaries, revealing tilt angle's dominant role and minimal rectification effects.

Contribution

It introduces a combined atomistic approach using PFC and MD to analyze interfacial heat transport in graphene/h-BN GBs, highlighting the impact of tilt angle over lattice mismatch.

Findings

Tilt angle significantly influences thermal conductance.

Lattice mismatch has a minor effect on heat transport.

No notable thermal rectification observed across GBs.

Abstract

We study the interfacial thermal conductance of grain boundaries (GBs) between monolayer graphene and hexagonal boron nitride (h-BN) sheets using a combined atomistic approach. First, realistic samples containing graphene/h-BN GBs with different tilt angles are generated using the phase-field crystal (PFC) model developed recently [P. Hirvonen \textit{et al.}, Phys. Rev. B \textbf{100}, 165412 (2019)] that captures slow diffusive relaxation inaccessible to molecular dynamics (MD) simulations. Then, large-scale MD simulations using the efficient GPUMD package are performed to assess heat transport and rectification properties across the GBs. We find that lattice mismatch between the graphene and h-BN sheets plays a less important role in determining the interfacial thermal conductance as compared to the tilt angle. In addition, we find no significant thermal rectification effects for these GBs.