Atomistic mechanism of graphene growth on SiC substrate: Large-scale molecular dynamics simulation based on a new charge-transfer bond-order type potential

TL;DR

This study develops a new interatomic potential for large-scale molecular dynamics simulations, revealing the atomistic process of graphene formation from silicon carbide and highlighting the role of substrate surface atoms.

Contribution

A novel charge-transfer bond-order potential enabling detailed simulation of graphene growth on SiC substrates.

Findings

Continuous growth process of multi-ring carbon structures observed.

Transformation of multi-ring structures into flat graphene demonstrated.

Surface atoms of SiC substrate promote homogeneous graphene formation.

Abstract

Thermal decomposition of silicon carbide is a promising approach for the fabrication of graphene. However, the atomistic growth mechanism of graphene remains unclear. This paper describes the development of a new charge-transfer interatomic potential. Carbon bonds with a wide variety of characteristics can be reproduced by the proposed vectorized bond-order term. Large-scale thermal decomposition simulation enables us to observe the continuous growth process of the multi-ring carbon structure. The annealing simulation reveals the atomistic process by which the multi-ring carbon structure is transformed to flat graphene involving only 6-membered rings. Also, it is found that the surface atoms of the silicon carbide substrate enhance the homogeneous graphene formation.