Atomic and electronic structure of a copper/graphene interface as prepared and 1.5 years after

TL;DR

This study investigates the stability and electronic structure of graphene on copper over 1.5 years using spectroscopy, Raman, and DFT calculations, revealing that high-quality graphene remains stable while defects influence longevity.

Contribution

It combines experimental spectroscopy and Raman data with DFT modeling to analyze long-term stability and defect effects in graphene/copper interfaces.

Findings

Graphene on high-quality copper remains stable over 1.5 years.

Defects in graphene and substrate affect interface stability.

A two-step model explains graphene oxidation and perforation.

Abstract

We report the results of X-ray spectroscopy and Raman measurements of as-prepared graphene on a high quality copper surface and the same materials after 1.5 years under different conditions (ambient and low humidity). The obtained results were compared with density functional theory calculations of the formation energies and electronic structures of various structural defects in graphene/Cu interfaces. For evaluation of the stability of the carbon cover, we propose a two-step model. The first step is oxidation of the graphene, and the second is perforation of graphene with the removal of carbon atoms as part of the carbon dioxide molecule. Results of the modeling and experimental measurements provide evidence that graphene grown on high-quality copper substrate becomes robust and stable in time (1.5 years). However, the stability of this interface depends on the quality of the graphene and the number of native defects in the graphene and substrate. The effect of the presence of a metallic substrate with defects on the stability and electronic structure of graphene is also discussed.