Ripple edge engineering of graphene nanoribbons

TL;DR

This paper investigates how functionalizing graphene nanoribbon edges with larger groups induces strain that leads to static ripples, affecting mechanical and electronic properties, with implications for device design.

Contribution

It demonstrates that edge functionalization causes strain-induced ripples in graphene nanoribbons, significantly altering their properties and likely being common in functionalized edges.

Findings

Edge functionalization induces strain and static ripples.

Ripples reduce Young's Modulus and modify band gaps.

Ripple formation is prevalent in functionalized GNR edges.

Abstract

It is now possible to produce graphene nanoribbons (GNRs) with atomically defined widths. GNRs offer many opportunities for electronic devices and composites, if it is possible to establish the link between edge structure and functionalisation, and resultant GNR properties. Switching hydrogen edge termination to larger more complex functional groups such as hydroxyls or thiols induces strain at the ribbon edge. However we show that this strain is then relieved via the formation of static out-of-plane ripples. The resultant ribbons have a significantly reduced Young's Modulus which varies as a function of ribbon width, modified band gaps, as well as heterogeneous chemical reactivity along the edge. Rather than being the exception, such static edge ripples are likely on the majority of functionalized graphene ribbon edges.