Topological Defects in Graphene: Dislocations and Grain Boundaries

TL;DR

This paper introduces a comprehensive method for constructing and analyzing topological defects like dislocations and grain boundaries in graphene, revealing their properties and potential for nanomaterial engineering.

Contribution

A general approach for creating and studying dislocations and grain boundaries in graphene with ab initio analysis of their properties.

Findings

Symmetric large-angle grain boundaries are energetically favorable.

Small-angle regimes tend to deform out-of-plane.

Defects significantly influence electronic structure.

Abstract

Topological defects in graphene, dislocations and grain boundaries, are still not well understood despites the considerable number of experimental observations. We introduce a general approach for constructing dislocations in graphene characterized by arbitrary Burgers vectors as well as grain boundaries, covering the whole range of possible misorientation angles. By using ab initio calculations we investigate thermodynamic and electronic properties of these topological defects, finding energetically favorable symmetric large-angle grain boundaries, strong tendency towards out-of-plane deformation in the small-angle regimes, and pronounced effects on the electronic structure. The present results show that dislocations and grain boundaries are important intrinsic defects in graphene which may be used for engineering graphene-based nanomaterials and functional devices.