Tunable electronic properties induced by a defect-substrate in graphene/BC3 heterobilayers.

We perform first-principles calculations to study the geometric, energetics and electronic properties of graphene supported on BC3 monolayer. The results show that overall graphene interacts weakly with BC3 monolayer via van der Waals interaction. The energy gap of graphene can be up to ∼0.162 eV in graphene/BC3 heterobilayers (G/BC3 HBLs), which is large enough for the gap opening at room temperature. We also find that the interlayer spacing and in-plane strain can tune the band gap of G/BC3 HBLs effectively. Interestingly, the characteristics of a Dirac cone with a nearly linear band dispersion relationship of graphene can be preserved, accompanied by a small electron effective mass, and thus the higher carrier mobility is still expected. These findings provide a possible way to design effective FETs out of graphene on a BC3 substrate.