Tunable magnetic and electronic properties in In2Se3/ScO2 van der Waals heterostructure induced by the vertical strain and electric field

Abstract

In this work, we studied the electronic and magnetic properties of In₂Se₃/ScO₂ van der Waals (vdW) heterojunctions using the first-principles calculations. The Young's modulus (Y) and Poisson's ratio (υ) of heterojunctions are obvious anisotropy and show potential application in flexible nanoelectronic devices. Computational analysis shows that In₂Se₃ as a nonmagnetic semiconductor, while ScO₂ manifests bipolar magnetic semiconducting behavior. Notably, In₂Se₃ exhibits spin splitting and a small magnetic moment at the Se atoms near the interface. When the electric dipole is oriented from ScO₂ to In₂Se₃, the heterojunction becomes a dual-polarized magnetic semiconductor, with the conduction band minimum (CBM) and valence band maximum (VBM) originating from different spin states. A type-II band alignment emerges between the two monolayers, with staggered valence and conduction bands across the interface, enhancing carrier dissociation. Moreover, the electronic and magnetic characteristics of the heterostructure can be dynamically modulated by mechanical strain and electric fields (E_ext). A positive E_ext eliminates In₂Se₃'s magnetism, while a negative E_ext induces magnetism at the edge of this monolayer, especially in the Se₃ atomic layer due to electronegativity differences and the weak built-in electric field. The strain can regulate the magnetic properties of heterojunction obviously, the changed magnetic moment of monolayers increases quickly with the raising compressive strain, and decreases gradually with rising interlayer distance.