Graphene Nanoengineering and the Inverse-Stone-Thrower-Wales Defect

TL;DR

This paper introduces the Inverse-Stone-Thrower-Wales defect as a new fundamental building block for nanoengineering on graphene, analyzing its structure, synthesis routes, and potential to form nanoscale features.

Contribution

It presents the theoretical analysis of the ISTW defect, proposes synthesis pathways, and demonstrates how to create nanoscale structures on graphene using this defect.

Findings

ISTW defect is energetically feasible with low barrier for formation.

Extended defect domains like blisters and ridges can be constructed at atomic scale.

Density functional theory effectively models defect properties and synthesis routes.

Abstract

We analyze a new fundamental building block for monolithic nanoengineering on graphene: the Inverse-Stone-Thrower-Wales (ISTW) defect. The ISTW is formed from a pair of joined pentagonal carbon rings placed between a pair of heptagonal rings; the well-known Stone-Thrower-Wales (STW) defect is the same arrangement, but with the heptagonal rather than pentagonal rings joined. When removed and passivated with hydrogen, the structure constitutes a new molecule, diazulene, which may be viewed as the result of an ad-dimer defect on anthracene. Embedding diazulene in the honeycomb lattice, we study the effect of ad-dimers on planar graphene. Because the ISTW defect has yet to be experimentally identified, we examine several synthesis routes and find one for which the barrier is only slightly higher than that associated with adatom hopping on graphene. ISTW and STW defects may be viewed as fundamental building blocks for monolithic structures on graphene. We show how to construct extended defect domains on the surface of graphene in the form of blisters, bubbles, and ridges on a length scale as small as 2 angstroms by 7 angstroms. Our primary tool in these studies is density functional theory.