  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.
