MoS2-graphene in-plane contact for high interfacial thermal conduction

TL;DR

This study designs and analyzes MoS2-graphene interfaces with strong covalent bonds, revealing high interfacial thermal conductance that can be modulated by vacancy control, offering solutions for heat management in MoS2 electronics.

Contribution

It introduces a novel interface design between MoS2 and graphene with covalent bonds, achieving high and tunable interfacial thermal conductance.

Findings

Interface thermal conductance is comparable to graphene-metal interfaces.

Covalent Mo-C bonds act as independent thermal channels.

Thermal conductance can be modulated by controlling Mo vacancies.

Abstract

Recent studies showed that the in-plane and inter-plane thermal conductivities of two-dimensional (2D) MoS2 are low, posing a significant challenge in heat management in MoS2-based electronic devices. To address this challenge, we design the interfaces between MoS2 and graphene by fully utilizing graphene, a 2D material with an ultra-high thermal conduction. We first perform ab initio atomistic simulations to understand the bonding nature and structure stability of the interfaces. Our results show that the designed interfaces, which are found to be connected together by strong covalent bonds between Mo and C atoms, are energetically stable. We then perform molecular dynamics simulations to investigate the interfacial thermal conductance. It is found surprisingly that the interface thermal conductance is high, comparable to that of graphene-metal covalent-bonded interfaces. Importantly, each interfacial Mo-C bond serves as an independent thermal channel, enabling the modulation of interfacial thermal conductance by controlling Mo vacancy concentration at the interface. The present work provides a viable route for heat management in MoS2 based electronic devices.