Optical properties of graphene antidot lattices

TL;DR

This paper investigates how creating a periodic array of holes in graphene, called antidot lattices, transforms it into a direct gap semiconductor with notable optical properties, useful for optoelectronic applications.

Contribution

It demonstrates through atomistic modeling that graphene antidot lattices are direct gap semiconductors with strong optical absorption, including effects of disorder and substrates.

Findings

Graphene antidot lattices have a direct optical gap.

They exhibit a pronounced optical absorption edge.

Disorder and substrates influence the optical properties.

Abstract

Undoped graphene is semi-metallic and thus not suitable for many electronic and optoelectronic applications requiring gapped semiconductor materials. However, a periodic array of holes (antidot lattice) renders graphene semiconducting with a controllable band gap. Using atomistic modelling, we demonstrate that this artificial nanomaterial is a dipole-allowed direct gap semiconductor with a very pronounced optical absorption edge. Hence, optical infrared spectroscopy should be an ideal probe of the electronic structure. To address realistic experimental situations, we include effects due to disorder and the presence of a substrate in the analysis.