▎ 摘　　要

Based on the first-principles calculations, we studied the structure and electronic properties of HfSSe/Graphene (HfSSe/Gr) and Graphene/HfSSe (Gr/HfSSe) van der Waals heterostructures (vdWHs) under the effects of external electric field and interlayer distance. The results show that the electronic properties of HfSSe/Gr and Gr/ HfSSe heterostructures are not sensitive to interlayer distance, and the heterostructures always maintain n-type Schottky contact when the interlayer distance changes. Under the different applied electric field, the Schottky barrier of heterostructures can be regulated from n-type Schottky contact to p-type Schottky contact, and it can be further adjusted to Ohmic contact. In summary, these results are useful in nanoelectronic and optoelectronic devices in the future experiments.