Tunable electronic and spin properties in 2D α-tellurene/α-In₂Se₃ bilayer ferroelectric heterostructure

Abstract Two-dimensional (2D) van der Waals heterostructures (vdWHs) incorporating ferroelectric properties and Rashba effects hold attractive applications in spintronics. In this work, the 2D α -tellurene and typical piezoelectric α -In 2 Se 3 are selected to form the bilayer α -tellurene/ α -In 2 Se 3 (Te/In 2 Se 3 ) vdWHs and the novel electronic, optical and spin characteristics are explored utilizing the first-principles calculations. We show that, firstly, the Te/In 2 Se 3 vdWH exhibits semiconductor nature as well as the super strong optical absorption characteristics in the visible region. Then, the pronounced spin–orbit coupling effect is revealed, which results from the heterostructure disrupting the symmetries of the individual monolayers. Furthermore, reversing the direction of ferroelectric polarization for the In 2 Se 3 monolayer can transform the Te/In 2 Se 3 vdWH between type-I and type-II heterostructures, also tuning the Rashba effect. And such electronic properties and Rashba effect can be tailored by strain and electric field. Our proposed Te/In 2 Se 3 vdWH will be potential candidate for applications in nanodevices, especially spin-field effect transistors.