Tunable band alignment in 2D ferroelectric In₂Se₃ based van der Waals heterostructures

Van der Waals heterostructures with the advantages of atomically sharp interfaces, digitally controlled layered components, and no lattice parameter constraint, have been attracted substantial research interests in recent years due to their great potentials in electronic and optoelectronic applications and such properties critically depend on the band alignment between the constituent layers. Here we, based on first-principles calculations, demonstrate that by taking advantage of a recently discovered 2D ferroelectric material In₂Se₃ its van der Waals heterostructures with other known 2D materials have the ability to tune their band alignment between different types of semiconductor junctions or the Schottky barrier height by switching the orientation of the electric polarization of the ferroelectric In₂Se₃ layer with an external electric field. This work provides a generic guideline for the application of the 2D ferroelectric In₂Se₃ in tuning the electronic properties of van der Waals heterostructures.