Bandgap Modulation of Graphene Using B ₃ C ₂ N ₃ as Substrate

Based on first‐principle calculations, the use of a flat monolayer of semiconducting B 3 C 2 N 3 as a substrate for graphene is proposed. Due to the inhomogeneous electric field arising from the charge transfer from the substrate to graphene, the characteristic Dirac bands are separated, opening a gap at the Fermi energy. Uniaxial compressive strain along the zigzag and tensile strain along the armchair crystallographic directions considerably enhance the bandgap further. The formation of van der Waals heterostructure breaks the spatial inversion symmetry and induces nonzero Berry curvature that can give rise to two‐qubit excitons. The bandgap tunability, along with such valleytronic property, paves a new way of engineering graphene‐based electronic and optoelectronic devices.