Tunable Band Alignments in 2D Ferroelectric α-In₂Se₃ Based Van der Waals Heterostructures

Abstract

Two-dimensional (2D) van der Waals (vdW) heterostructures have attracted substantial research interest in recent years, due to their tremendous advantages, such as atomically sharp interfaces, digitally controlled layered components, and unconstraint lattice mismatch, and immense potentials, in electronic and optoelectronic applications. The functionality and performance of such vdW heterostructures critically depend on the band alignment between the constituent layers. In this work, based on systematic first-principles calculations, we demonstrate that by taking advantage of the out-of-plane ferroelectricity of a 2D ferroelectric material α-In 2 Se 3 , the band alignments of a large variety of α-In 2 Se 3 based vdW heterostructures can be controllably switched between different types of semiconductor or metal−semiconductor junctions via the polarization reversal of the ferroelectric α-In 2 Se 3 layer upon the application of an external electric field. This work provides a generic guideline for the application of 2D ferroelectric α-In 2 Se 3 in tuning the electronic and optical properties of vdW heterostructures for device applications.

Ferroelectricity controlled chiral spin textures and anomalous valley Hall effect in the Janus magnet-based multiferroic heterostructure

“…As described in Section S3 of Supplementary material, we consider twelve stacking configurations of LaXY/P↓ [Figure S3] and calculate the corresponding total energy [Figure S4]. We find that the P↓ state is always energetically more stable than P↑ state, which is consistent with previously generic trend [27]. The magnetic properties can be regulated by changing the interfacial coupling, when revers the OOP polarization of In2Se3 in the LaXY/In2Se3 HS.…”

In-plane ferroelectric tunnel junctions based on 2D α-In2Se3/semiconductor heterostructures

“…Si et al reported an asymmetric metal/α-In 2 Se 3 /Si crossbar ferroelectric semiconductor junction with an ON/OFF ratio >10 4 at room temperature 36 . Also, several theoretic works have been published focusing on the band alignment of 2D α-In 2 Se 3 heterostructures controlled by the OOP polarization of α-In 2 Se 3 , which leads to about 1.1 eV potential difference between its two surfaces [37][38][39] . Ferroelectric control of the band alignment is important for the design of FTJs and other types of memory devices.…”

Ferroelectric Control of Magnetic Skyrmions in Two-Dimensional van der Waals Heterostructures

“…The recently discovered 2D ferroelectric materials, ,,, such as In 2 Se 3 , − can be used to mediate this effect. Due to their switchable electric polarization, − the 2D ferroelectrics can provide a voltage tunable interface proximity effect to other 2D materials. In particular, the electric polarization of a 2D ferroelectric is expected to efficiently control DMI in an adjacent 2D ferromagnet.…”

“…Monolayer In 2 Se 3 contains five triangular lattices stacked with the Se–In–Se–In–Se sequence. The central Se atom is located at one of the two asymmetric but topologically identical sites, associated with a finite out-of-plane polarization pointing in opposite directions. , Recent reports show that In 2 Se 3 can be effectively used in vdW heterostructures to provide a nonvolatile control of 2D electronic structures despite very weak interlayer coupling. − Due to both having hexagonal atomic structures and similar in-plane lattice constants, , Fe 3 GeTe 2 and In 2 Se 3 are well matched to construct commensurate vdW heterostructures. In such heterostructures, the and symmetries are broken, making DMI finite and thus the appearance of magnetic skyrmions possible.…”