Quantum Transport in Nitrogen-Doped Nanoporous Graphenes

Bottom-up on-surface synthesized nanoporous graphenes (NPGs), realized as 2D arrays of laterally covalently bonded π-conjugated graphene nanoribbons (GNRs), are a family of carbon nanomaterials that are receiving increasing attention for nanoelectronics and biosensing. Recently, a so-called hybrid-NPG (hNPG) is synthesized, featuring an alternating sequence of doped and non-doped GNRs, resulting in a band staggering effect in its electronic structure. Such a feature is appealing for photo-catalysis, photovoltaics and even carbon nanocircuitry. However, to date, little is known about the transport properties of hNPG and its derivatives, which is key for most applications. Here, via Green's functions simulations, the quantum transport properties of hNPGs are studied. It is found that injected carriers in hNPG spread laterally through a number of GNRs, though such spreading may take place exclusively through GNRs of one type (doped or non-doped). A simple model is proposed to discern the key parameters determining the electronic propagation in hNPGs and explore alternative hNPG designs to control the spreading/confinement and anisotropy of charge transport in these systems. For one such design, it is found that it is possible to send directed electric signals with sub-nanometer precision for as long as one micrometer - a result first reported for any NPG.