Interlayer coupling dependent spin and valley polarization in a two-dimensional metal-semiconductor contact heterostructure

Interface engineering has become a new research field recently. Transition metal dichalcogenides, as a kind of graphenelike two-dimensional semiconductor layered material, can be constructed as rich heterostructures with various other materials, which helps to fully explore the modulation effect of interlayer interaction. Based on first-principles calculation, it is found that ${\mathrm{MoS}}_{2}$/${\mathrm{FeCl}}_{2}$ is a typical metal-semiconductor contact heterostructure with a variety of novel physical properties, including unconventional band alignment, the coexistence of spintronics and valleytronics, and the abnormal valley Hall effect. The change of interlayer interaction leads to the effective regulation of band structure in the system, and the interlayer coupling transforms between weak vdWs force and covalentlike quasibonding interaction depending on the interlayer distance. The transition from $n$-type to $p$-type Schottky contact at the interface of the system is also achieved by interlayer engineering. Meanwhile, under the influence of magnetic proximity effect, the heterostructure presents a robust ferromagnetic ground state, but the magnetic anisotropy energy can be transferred from in-plane to out-of-plane. Remarkably, manipulating interlayer coupling through magnetization direction or interlayer proximity can result in alterations of spin and valley polarization. Once synthesized, the ${\mathrm{MoS}}_{2}$/${\mathrm{FeCl}}_{2}$ heterostructure is a potential candidate for multifunctional applications.