van der Waals heterostructures based on allotropes of phosphorene and MoSe2

The van der Waals heterostructures of allotropes of phosphorene (alpha- and beta-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, beta-P/H-MoSe2 and alpha-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. alpha-P/ZT-MoSe2 and alpha-P/SO-MoSe2 form ohmic semiconductor-metal contacts while the Schottky barrier in beta-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 alpha-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.