Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films on sapphire

TL;DR

This paper reports the successful growth of high-quality, single-layer epitaxial graphene on single-crystal iridium films prepared by pulsed laser deposition on sapphire, demonstrating comparable quality to bulk iridium substrates.

Contribution

It introduces a method to produce high-quality epitaxial graphene on thin iridium films on sapphire, expanding substrate options for graphene synthesis.

Findings

Graphene has a single crystallographic orientation.

Graphene exhibits very low defect density.

Structural quality is comparable to bulk iridium-based graphene.

Abstract

Uniform single layer graphene was grown on single-crystal Ir films a few nanometers thick which were prepared by pulsed laser deposition on sapphire wafers. These graphene layers have a single crystallographic orientation and a very low density of defects, as shown by diffraction, scanning tunnelling microscopy, and Raman spectroscopy. Their structural quality is as high as that of graphene produced on Ir bulk single crystals, i.e. much higher than on metal thin films used so far.