Stabilization of Stone-Wales Defects in Metal-supported Graphene

Abstract

The characteristics of graphene-metal interfaces play a decisive role in their electronic, optoelectronic, and mechanical applications. Properties such as charge transfer across the interface become particularly significant in the presence of topological defects. The stability of Stone Wales (SW) defects in graphene is governed by the balance between three energy descriptors, the activation energy, formation energy, and restoration energy. By comparing the energy parameters obtained from first-principles density functional theory calculations, we show that SW defect formation is energetically more favorable on metal-supported graphene. Our calculations for SW defects in graphene/Cu(111) and graphene/Al(111) systems indicate only a little dependence of energy profile on the type of metal. The presence of the metal substrate leads to a $\sim$ 12\% increase in the formation energy and a $\sim$ 20\% reduction in the activation energy, which together favor the formation of Stone Wales defects. Although the restoration energy decreases by about $\sim$ 35\% in metal-supported graphene, it remains significantly higher to prevent self-healing. As a result, once formed, the Stone Wales defects are likely to remain stable, suggesting the possibility of terminal SW defect formation in metal-supported graphene.