Graphyne on metallic surfaces: an improved graphene

TL;DR

This study investigates how structural modifications of graphene to form graphyne, combined with adsorption on metallic surfaces, influence energy gaps and charge transfer, using advanced density functional theory calculations.

Contribution

It demonstrates how graphyne's energy gap can be modulated by surface interactions and charge transfer, providing insights into its potential for electronic applications.

Findings

Graphyne induces an energy gap at the K point of the Brillouin zone.

Adsorption on metallic surfaces further modifies the energy gap via charge transfer.

Graphyne binds more strongly to metal surfaces than graphene.

Abstract

We showed how a structural modification of graphene, which gives a carbon allotrope graphyne, can induce an energy gap at the K point of the Brillouin zone. Upon adsorption on metallic surfaces, the same mechanism is responsible for the further modification of the energy gap which occurs via the charge transfer mechanism. We performed the calculation based on the density functional theory with the novel non-local vdW-DF correlation of the adsorption of graphyne on Cu(111), Ni(111) and Co(0001) surfaces and showed the dependence of the gap change on the charge transfer in the system. The binding of graphyne appears to be stronger than of graphene on the same surfaces.