Stacking-dependent Rashba spin-splitting in Janus bilayer transition metal dichalcogenides: The role of in-plane strain and out-of-plane electric field

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2021-08, Vol.132, p.114768, Article 114768
• Main Authors: Rezavand, Amirhossein, Ghobadi, Nayereh
• Format: Article
• Language: English
• Subjects: Density functional theory; In-plane biaxial strain; Janus transition metal dichalcogenides; Out-of-plane electric field; Rashba spin-splitting
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2021.114768

In this paper, we have applied first-principles calculations to investigate the structural, electronic and spintronic properties of the two-dimensional (2D) Janus bilayer transition metal dichalcogenides (TMDs) (MXY; M = Mo, W; X, YS, Se, Te). In Janus bilayer TMDs breaking out-of-plane symmetry causes intrinsic electric field which induces Rashba spin-splitting at the Γ-point in valence band and Zeeman-type spin-splitting at the K-point of both valence band and conduction band. Fifteen different stacking patterns of MoSeTe as an example have been investigated to find the most stable structures and the stacking configurations with Rashba spin-splitting. We have manipulated these spin properties by applying an external electric field parallel to the internal electric field to enhance the strength of it. Furthermore, we have explored the effect of in-plane biaxial strain on the electrical and spin properties of structures. Applying strain can significantly change and control the value of Rashba spin-splitting by modifying the orbitals overlap which can adjust the intrinsic electric field. Finally, our results are helpful in understanding the stacking-dependent Rashba spin-splitting in bilayer Janus transition-metal dichalcogenides and promote the application of bilayer MXY in spintronic applications. •The electronic and spintronic properties of fifteen stacking orders of bilayer MXY (M=Mo, W; X, Y=S, Se, Te) are studied.•Breaking out-of-plane symmetry leads to an intrinsic electric field and Rashba splitting at the Γ-point in valance band.•Rashba splitting only appears in XY vertical configurations which is larger in structures with heavier chalcogenide atoms.•Tensile strain and positive electric field decrease the band gap and a semiconductor to the metal transition occurs.•Rashba spin-splitting is enhanced by a positive electric field and compressive strain.