The role of defects in the etching of graphene by intercalated oxygen

TL;DR

This study investigates how intentionally introduced defects in graphene on Ru(0001) influence oxygen intercalation and etching, revealing that defects facilitate oxygen penetration and enhance graphene etching during heating.

Contribution

It demonstrates that carbon vacancy defects significantly promote oxygen intercalation and etching efficiency in graphene on Ru(0001), providing insights into defect-controlled etching processes.

Findings

Defects ease oxygen intercalation into graphene.

Defects improve etching efficiency during annealing.

Vacancy defects facilitate graphene removal.

Abstract

Graphene is one of the most promising 2D materials for various applications due to its unique electronic properties and high thermal stability. In previous studies, it was shown that when graphene is deposited onto some transition metal substrates, small molecules, such as O$_2$, intercalate between the graphene and the substrate and react to partially etch the graphene film when heated to desorb the intercalates. Here, carbon vacancy defects are intentionally formed on Gr/Ru(0001) and their effect on the intercalation of oxygen and etching of the graphene layer are investigated. 50 eV Ar$^+$ sputtering with a low fluence is used to create isolated single vacancy defects in the graphene overlayer and helium low energy ion scattering (LEIS) is employed for surface analysis. It is found that the defects both ease the intercalation of the oxygen molecules and improve the etching efficiency of the graphene during annealing.