Thermal Transport in Amorphous Graphene with Varying Structural Quality

TL;DR

This study investigates how the structural quality of amorphous graphene affects its thermal transport properties, revealing that thermal conductivity can be tuned over two orders of magnitude by controlling amorphousness.

Contribution

It provides a systematic analysis linking structural disorder in amorphous graphene to vibrational modes and thermal conductivity, offering design guidelines for applications.

Findings

Thermal conductivity varies by over two orders of magnitude with amorphousness.

Energy dissipation is linked to vibrational mode localization.

Structural control via growth temperature influences thermal properties.

Abstract

The synthesis of wafer-scale two-dimensional amorphous carbon monolayers has been recently demonstrated. This material presents useful properties when integrated as coating of metals, semiconductors or magnetic materials, such as enabling efficient atomic layer deposition and hence fostering the development of ultracompact technologies. Here we propose a characterization of how the structural degree of amorphousness of such carbon membranes could be controlled by the crystal growth temperature. We also identify how energy is dissipated in this material by a systematic analysis of emerging vibrational modes whose localization increases with the loss of spatial symmetries, resulting in a tunable thermal conductivity varying by more than two orders of magnitude. Our simulations provide some recipe to design most suitable "amorphous graphene" based on the target applications such as ultrathin heat spreaders, energy harvesters or insulating thermal barriers.