Defect-Dependent Corrugation in Graphene

TL;DR

This study uses machine learning-driven molecular dynamics simulations to explore how various defects influence the corrugation and morphology of graphene, revealing that defect type and concentration significantly alter its surface structure.

Contribution

It provides new insights into the relationship between defect characteristics and graphene's structural morphology through large-scale simulations.

Findings

Defects increase graphene's surface corrugation and wrinkling.

The extent of morphological change depends on defect type and concentration.

Local defect environment influences global structural properties.

Abstract

Graphene's intrinsically corrugated and wrinkled topology fundamentally influences its electronic, mechanical, and chemical properties. Experimental techniques allow the manipulation of pristine graphene and the controlled production of defects which allows to control the atomic out-of-plane fluctuations and, thus, tune graphene's properties. Here, we perform large scale machine learning-driven molecular dynamics simulations to understand the impact of defects on the structure of graphene. We find that defects cause significantly higher corrugation leading to a strongly wrinkled surface. The magnitude of this structural transformation strongly depends on the defect concentration and specific type of defect. Analysing the atomic neighborhood of the defects reveals that the extent of these morphological changes depends on the preferred geometrical orientation and the interactions between defects. While our work highlights that defects can strongly affect graphene's morphology, it also emphasises the differences between distinct types by linking the global structure to the local environment of the defects.