Ferroelectric and dipole control of band alignment in the two dimensional InTe/In₂Se₃ heterostructure

Two dimensional (2D) ferroelectric materials are gaining growing attention due to their nontrival ferroelectricity, and the 2D ferroelectric heterostructures with tunable electronic, optoelectronic, or even magnetic properties, show many novel properties that do not exist in their constituents. In this work, by using the first-principles calculations, we investigate the ferroelectric and dipole control of electronic structures of the 2D ferroelectric heterostructure InTe/In₂Se₃. It is found that band alignment is closely dependent on the ferroelectric polarization of In₂Se₃. By switching the polarization of In₂Se₃, the band alignment of InTe/In₂Se₃ switches from a staggered (type II) to a straddling type (type I), and the band gap changes from indirect gap 0.76 eV to direct gap 0.15 eV. When the ferroelectric field of In₂Se₃ is reversed, the band alignment of InTe/In₂Se₃ switches from type-I to type-II, and the band gap changes from indirect gap 0.76 eV to direct gap 0.15 eV. In addition, we find that the interlayer dipole can also effectively modulate the band structure and induce the type-I to type-II band alignment transition. Our present results indicate that the 2D ferroelectric heterostructure with the tunable band alignment and band gap can be of great significance in the optoelectronic devices.