Two-Dimensional Ferroelectricity in a Single-Atom Adsorbed BiI₃ Monolayer

Abstract

Two-dimensional (2D) ferroelectric materials have received tremendous attention in recent years for their potential applications in high-performance electronic nanodevices, such as ferroelectric random-access memories. To increase the density of a ferroelectric memory, a 2D ferroelectric material with multiple ferroelectric states controllable via an external electric field is needed. However, 2D ferroelectric materials are still rare and most of them only have two equivalent ferroelectric states with opposite electric polarization directions. Here, we propose that a 2D ferroelectric material with multiple ferroelectric states can be realized by single-atom adsorption on a metal halide monolayer. Using first-principles calculations, we demonstrate that the 2D BiI3 monolayer adsorbed by Pd single atoms (denoted as Pd@BiI3) is a stable ferroelectric material, which possesses six equivalent ferroelectric states with different electric polarization directions. These findings provide a potential route to achieve multi-state 2D ferroelectric materials for multi-functional device applications.

Polar materials for photocatalytic applications: A critical review

“…">Currently, the use of 2D ferroelectric materials in photocatalysis is limited, despite their potential due to unique electronic and surface properties. Two‐dimensional ferroelectric materials, such as black phosphorous‐like Bi, [ 189 ] CuCrS 2 , [ 190 ] and BiI 3 [ 191 ] , exhibit exceptional ferroelectric performance and stable chemical properties and have also shown potential ferroelectric characteristics. The ferroelectric polarization of these materials can promote the effective separation of photogenerated charges, thereby enhancing photocatalytic efficiency.…”

Auxetic and multiferroic MP5 (M = Al, Ga): a novel 2D material with negative Possion's ratio and high anisotropic carrier mobility

“…Some reported examples include α-MPI (M = Zr, Hf), 17 borophane, 18 PdSe 2 , 19 and InBi 20 as 2D ferroelastic materials. Additionally, WTe 2 , 21 1T-MoS 2 , 22 and BiI 3 23 have been identified as ferroelectric materials. However, the literature lacks reports on multiferroic materials exhibiting both ferroelasticity and ferroelectricity.…”