Instability of two dimensional graphene: Breaking sp2 bonds with soft X-rays

TL;DR

This study investigates how soft X-ray irradiation affects the stability of graphene, revealing that monolayer graphene's bonds are unstable while multilayer and substrate-supported graphene are more resistant, with implications for nanostructure patterning.

Contribution

It demonstrates the role of third-dimensional interactions in stabilizing graphene under X-ray exposure and explores potential for X-ray patterning of graphene nanostructures.

Findings

Single-layer graphene bonds are unstable under X-ray irradiation.

Multilayer and substrate-supported graphene are more resistant to X-ray effects.

X-ray can be used to pattern exfoliated graphene nanostructures.

Abstract

We study the stability of various kinds of graphene samples under soft X-ray irradiation. Our results show that in single layer exfoliated graphene (a closer analogue to two dimensional material), the in-plane carbon-carbon bonds are unstable under X-ray irradiation, resulting in nanocrystalline structures. As the interaction along the third dimension increases by increasing the number of graphene layers or through the interaction with the substrate (epitaxial graphene), the effect of X-ray irradiation decreases and eventually becomes negligible for graphite and epitaxial graphene. Our results demonstrate the importance of the interaction along the third dimension in stabilizing the long range in-plane carbon-carbon bonding, and suggest the possibility of using X-ray to pattern graphene nanostructures in exfoliated graphene.