First-principle insights of electronic properties of Blue Phosphorus/MoSi2N4 van der Waals heterostructure via vertical electric field and biaxial strain

Very recently, a new kind of 2D transition metal nitride, MoSi2N4, have been attracting considerable attention due to its successful synthesis and outstanding properties. To further explore its novel properties and applications for nanodevices, we proposed a van der Waals (vdW) heterostructure composed of MoSi2N4 and Blue Phosphorus (BlueP) monolayers and systematically studied its electronic properties with first-principle calculation. The results reveal that the BlueP/MoSi2N4 heterostructure exhibits a type-II band alignment, with the conduction band minimum (CBM) and valence band maximum (VBM) located in BlueP and MoSi2N4 layers, respectively. The electronic properties of the heterostructure are not sensitive to the diverse stacking configurations while can be significantly modulated by applying an external electric field and biaxial strain. When applying an external electric field, the bandgap and band offsets show linear variation with electric field, and a transition from semiconductor to metal is observed under critical electric field. When applying biaxial strain, the bandgap and band offsets can also be tuned and a type-II band alignment is preserved in a wide range of strains. Under moderate compressive or tensile strain, the band alignment can be transformed from type-II to type-I. This work provides theoretical guidance for the design of flexible nano-electronic and optoelectronic devices based on the BlueP/MoSi2N4 heterostructure. •The BlueP/MoSi2N4 heterostructure exhibits a type-II band alignment.•The electronic properties of heterostructure are not sensitive to diverse stacking patterns.•The electronic properties of heterostructure can be tuned by external electric field or biaxial strain.•A semiconductor-to-metal transition takes place when applying a strong electric field.•Band alignment transition from type-II to type-I has been observed under the effect of biaxial strain.