Semimetallic 2D Defective Graphene Networks with Periodic 4–8 Defect Lines

Theoretical simulations of the electronic properties of graphene‐like 2D carbon networks with a periodic arrangement of defect lines formed by alternating four‐ and eight‐membered rings are presented. These networks can be seen as arrays of armchair‐edged nanoribbons (AGNRs), which are covalently connected at the edges. Using a combination of density functional theory and a simple tight binding model, it is shown that the electronic properties of these networks can be understood to arise from the family behavior of the constituting AGNRs, plus a rigid shift due to an “inter‐ribbon” coupling across the defect lines. As a result, one class of zero‐bandgap semiconducting 2D networks and two classes of semimetallic networks with quasilinear band close to the Fermi energy are found. The formation of closed‐ring electron‐ and hole‐like Fermi surfaces due to hybridization across the defect lines offers interesting perspectives of using such defective 2D networks for transport applications or the realization of carbon‐based nodal‐line semimetals.