Large Rashba splitting, carrier mobility, and valley polarization in a 1T-SnS2/MoTe2 heterostructure

Abstract

The structural and electronic properties of the 1T-SnS₂/MoTe₂ heterostructure were investigated based on density functional theory and Berry curvature calculations. Considering the strong spin–orbit coupling and space inversion asymmetry, large Rashba spin splitting of electronic bands appeared in this hybrid system. The Rashba coupling parameter α_R in 1T-SnS₂/MoTe₂ reached 0.383 eV Å. Importantly, α_R can be effectively tuned by biaxial strain. Moreover, our first-principles calculations show that the 1T-SnS₂/MoTe₂ heterostructure possesses a high carrier mobility of 5038.46 cm² V⁻¹ s⁻¹. The Berry curvature and spin splitting were opposite at the K and K′ valleys. Hence, the valleys and spins were simultaneously locked and polarized, and the valley and spin Hall effects simultaneously occurred.