Computational investigations of the metal/semiconductor NbS2/boron phosphide van der Waals heterostructure: effects of an electric field

Abstract

In this work, we design computationally the metal–semiconductor NbS₂/BP heterostructure and investigate its atomic structure, electronic properties and contact barrier using first-principles prediction. Our results show that the M–S NbS₂/BP heterostructure is energetically stable and is characterized by weak vdW interactions. Interestingly, we find that the combination of the metallic NbS₂ and semiconducting BP layers leads to the formation of a M–S contact. The M–S NbS₂/BP heterostructure exhibits a p-type Schottky contact and a low tunneling-specific resistivity of 3.98 × 10⁻¹⁰ Ω cm², indicating that the metallic NbS₂ can be considered as an efficient 2D electrical contact to the semiconducting BP layer to design NbS₂/BP heterostructure-based electronic devices with high charge injection efficiency. The contact barrier and contact type in the M–S NbS₂/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 NbS₂/BP heterostructure demonstrates that it can be considered as a promising material for next-generation electronic devices.