Wetting and energetics in nanoparticle etching of graphene

TL;DR

This paper introduces a simple, general model explaining how molten metal nanoparticles etch graphene by considering wettability differences and edge energy, providing testable predictions and extending to other material systems.

Contribution

The paper presents a novel, general model for nanoparticle-induced graphene etching that incorporates wettability and edge energy effects, applicable to various materials systems.

Findings

Calculated etching velocities based on wettability and edge energy.

Provided testable predictions for etching mechanisms.

Extended the model to droplet motion on semiconductor surfaces.

Abstract

Molten metallic nanoparticles have recently been used to construct graphene nanostructures with crystallographic edges. The mechanism by which this happens, however, remains unclear. Here, we present a simple model that explains how a droplet can etch graphene. Two factors possibly contribute to this process: a difference between the equilibrium wettability of graphene and the substrate that supports it, or the large surface energy associated with the graphene edge. We calculate the etching velocities due to either of these factors and make testable predictions for evaluating the significance of each in graphene etching. This model is general and can be applied to other materials systems as well. As an example, we show how our model can be used to extend a current theory of droplet motion on binary semiconductor surfaces.