Polaron transport in porous graphene nanoribbons

Porous graphene (PG) forms a class of graphene-related materials with nanoporous architectures. Their unique atomic arrangements present interconnected networks with high surface area and high pore volume. Some remarkable properties of PG, such as high mechanical strength and good thermal stability, have been widely studied. However, their electrical conductivity, and most importantly, their charge transport mechanism are still not fully understood. Herein, we employed a numerical approach based on a 2D tight-binding model Hamiltonian to first reveal the nature of the charge transport mechanism in PG nanoribbons. Results showed that the charge transport in these materials is mediated by charge density waves. These carrier species are dynamically stable and present very shallow lattice distortions. The porosity allows for an alternative to the usual arising of polaron-like charge carriers and it can preserve the PG semiconducting character even in broader nanoribbons. The charge density waves move in PG within the optical regime with terminal velocities varying from 0.50 up to 1.15 A/fs. These velocities are lower than the ones for polarons in conventional graphene nanoribbons (2.2-5.1 A/fs).