Strains Induced by Point Defects in Graphene on a Metal

TL;DR

This study investigates how point defects induce significant strains in graphene during growth and processing, revealing microscopic defect-strain relationships and suggesting methods for nanostructuring and property engineering.

Contribution

It combines experimental and computational approaches to elucidate the microscopic relationship between point defects and strains in epitaxial graphene on a metal substrate.

Findings

Strains above 2% are observed in graphene during growth and processing.

Point defects are directly linked to local strain variations.

Defect engineering can be used to tailor graphene's properties.

Abstract

Strains strongly affect the properties of low-dimensional materials, such as graphene. By combining in situ, in operando, reflection high energy electron diffraction experiments with first-principles calculations, we show that large strains, above 2%, are present in graphene during its growth by chemical vapor deposition on Ir(111) and when it is subjected to oxygen etching and ion bombardment. Our results unravel the microscopic relationship between point defects and strains in epitaxial graphene and suggest new avenues for graphene nanostructuring and engineering its properties through introduction of defects and intercalation of atoms and molecules between graphene and its metal substrate.