Sublattice asymmetry of impurity doping in graphene: A review

TL;DR

This review discusses recent advances in sublattice asymmetric doping of graphene, focusing on how selective impurity placement can open a tunable band gap and enable quasi-ballistic electron transport, crucial for future electronic applications.

Contribution

It synthesizes current experimental and theoretical research on sublattice asymmetric doping in graphene, highlighting mechanisms and future research directions.

Findings

Sublattice doping can open a tunable band gap in graphene.

Experimental techniques for sublattice-specific doping are advancing.

Theoretical models explain mechanisms behind sublattice asymmetry effects.

Abstract

In this review we highlight recent theoretical and experimental work on sublattice asymmetric doping of impurities in graphene, with a focus on substitutional Nitrogen dopants. It is well known that one current limitation of graphene in regards to its use in electronics is that in its ordinary state it exhibits no band gap. By doping one of its two sublattices preferentially it is possible to not only open such a gap, which can furthermore be tuned through control of the dopant concentration, but in theory produce quasi-ballistic transport of electrons in the undoped sublattice, both important qualities for any graphene device to be used competetively in future technology. We outline current experimental techniques for synthesis of such graphene monolayers and detail theoretical efforts to explain the mechanisms responsible for the effect, before suggesting future research directions in this nascent field.