Ordered boron phosphorus codoped graphene realizing widely tunable quasi Dirac-cone gap

Abstract

In order to address the present challenges in generating a sizeable Dirac-cone gap for monolayer graphene, primarily due to the robust symmetry dependency and protection, we intentionally investigate ternary graphene lattices by pairing IIIA–VA atom substitution. We demonstrate by first-principles calculations an ordered boron-phosphorus codoped graphene (C₄BP) monolayer realizing a sizable ∼0.24 eV and simultaneously strain-tunable-reclosed quasi Dirac-cone gap. The peculiar band topology is attributed to unique symmetry breaking of the primary graphene lattice by the ordered doping coordination and resulting electronic couplings, which also endow the material with appealing properties comparable to the parent graphene, e.g., ultrahigh carrier mobility (>10⁵ cm² V⁻¹ s⁻¹) and Fermi velocity (>0.8 × 10⁶ m s⁻¹) as well as a topologically nontrivial phase but with a more appreciable SOC gap. The predicted high dynamic, thermal and energetic stabilities support its experimental viability. Our result opens up a new branch for band engineering of versatile graphene.