Tuning the Rashba spin splitting in Janus MoSeTe and WSeTe van der Waals heterostructures by vertical strain

In this work, the electronic and spintronic properties of the five various stacking orders of bilayer MoSeTe, bilayer WSeTe, and MoSeTe/WSeTe van der Waals heterostructure under vertical strain is investigated using the first-principles calculations. It is observed that bilayer WSeTe is the most stable material and AA and AB stack patterns are the most stable configurations. The bandgap of the structures tends to decrease by increasing compressive strain and transition from semiconductor to metal occurs under specific compressive strain. In considered Janus TMD compounds, obvious out-of-plane asymmetry endows intrinsic electric potential difference and induces Rashba type spin-splitting at the Γ-point of valance band. Moreover, vertical strain can considerably improve the Rashba coefficient values in the different stacking patterns. Finally, our results could lead to a full understanding of the electronic and spintronic features of the WSeTe/MoSeTe, bilayer MoSeTe, and bilayer WSeTe compounds for application in spintronic devices.