▎ 摘　　要

Based on first-principles calculations, the electronic structures of the van der Waals heterostructures formed by bilayer-Bi(111) and graphene are systematically studied. Although the Bi-graphene spacing is larger than 3 angstrom, the topological bandgap (TBG) of bilayer-Bi(111) can be tuned by the weak Bi-graphene interaction and the stacking pattern between Bi and graphene. In the zigzag-zigzag stacking pattern, the TBG can be enlarged by reducing the Bi-graphene spacing or the buckling of bilayer-Bi(111). Interestingly, in the zigzag-armchair stacking pattern, there is a new hybridization gap in a bilayer-Bi(111) near Fermi level. Meanwhile, the TBG of bilayer-Bi(111) can also be modified in the heterostructures. However, a large bandgap (more than 100 meV) can be realized in graphene by tuning the Bi-graphene spacing. The calculations suggest the importance of stacking pattern and hybridization on the electronic structures.