Computational investigations of the metal/semiconductor NbS/boron phosphide van der Waals heterostructure: effects of an electric field.

In this work, we design computationally the metal-semiconductor NbS/BP heterostructure and investigate its atomic structure, electronic properties and contact barrier using first-principles prediction. Our results show that the M-S NbS/BP heterostructure is energetically stable and is characterized by weak vdW interactions. Interestingly, we find that the combination of the metallic NbS and semiconducting BP layers leads to the formation of a M-S contact. The M-S NbS/BP heterostructure exhibits a p-type Schottky contact and a low tunneling-specific resistivity of 3.98 × 10 Ω cm, indicating that the metallic NbS can be considered as an efficient 2D electrical contact to the semiconducting BP layer to design NbS/BP heterostructure-based electronic devices with high charge injection efficiency. The contact barrier and contact type in the M-S NbS/BP heterostructure can be adjusted by applying an external electric field. The conversion from p-type ShC to n-type ShC can be achieved by applying a negative electric field, while the transformation from ShC to OhC type can be achieved under the application of a positive electric field. The conversion between p-type and n-type ShC and ShC to OhC type in the NbS/BP heterostructure demonstrates that it can be considered as a promising material for next-generation electronic devices.