SnS nanoribbon/graphene mixed-dimensional heterostructures: Group VII passivation and quantum size effects

The mixed-dimensional van der Waals heterostructures (vdWHs) are attracting extensive attention in the electronic and optoelectronic device, while the related physics mechanisms are still unclear. Here, we study theoretically the stability and electronic properties of the SnS nanoribbon (SnSNR)/graphene mixed-dimensional vdWHs. The results show that these considered mixed-dimensional vdWHs are energetically stable, and Dirac-cone of graphene is close to the top of valence band of SnSNR and thus p-type Schottky contact is formed. Interestingly, group VII passivation can induce transformation from p-type to n-type Schottky contact. Particularly for the F-passivated case, the Fermi level is closer to the CBM of SnSNR. Also, quantum size of SnSNR slightly decreases the p-type Schottky barrier height (SBH). Therefore, this work understands the physics mechanism and related experiments of graphene-based mixed-dimensional vdWHs.