van der Waals heterostructures based on allotropes of phosphorene and MoSe₂

The van der Waals heterostructures of allotropes of phosphorene (α- and β-P) with MoSe₂ (H-, T-, ZT- and SO-MoSe₂) are investigated in the framework of state-of-the-art density functional theory. The semiconducting heterostructures, β-P/H-MoSe₂ and α-P/H-MoSe₂, form anti-type structures with type I and type II band alignments, respectively, whose bands are tunable with an external electric field. α-P/ZT-MoSe₂ and α-P/SO-MoSe₂ form ohmic semiconductor-metal contacts while the Schottky barrier in β-P/T-MoSe₂ can be reduced to zero by an external electric field to form ohmic contacts which is useful to realize high-performance devices. Simulated STM images of the given heterostructures reveal that α-P can be used as a capping layer to differentiate between various allotropes of underlying MoSe₂. The dielectric response of the considered heterostructures is highly anisotropic in terms of lateral and vertical polarization. The tunable electronic and dielectric response of van der Waals phosphorene/MoSe₂ heterostructures may find potential applications in the fabrication of optoelectronic devices.