Recent progress on 2D ferroelectric and multiferroic materials, challenges, and opportunity

Extremely promising monolayer materials with robust ferroelectricity and extraordinary piezoelectricity: δ-AsN, δ-SbN, and δ-BiN

“…The phenomena have been reported in the previous literature. 8,23,45 Meanwhile, the previous ferroelectric switching energy barrier is basically a single parabola shape instead of a hump shape, which also brings difficulties to parameter fitting. Therefore, this work uses direct and accurate MD simulations to evaluate the Curie temperature T c .…”

2D Heterostructures for Ubiquitous Electronics and Optoelectronics: Principles, Opportunities, and Challenges

“…We hope these updates would be a suitable way to show representative 2D materials available to date. Since the significant influence of semiconductor junctions, new discoveries of low-dimensional materials have undergone an explosive expansion recently, such as 2D magnetic materials − (especially another family of 2D magnetic materials), , 2D ferroelectric and multiferroic materials, ,− 2D complex metallic dichalcogenide materials, − 2D superconducting materials, − 2D carbon families, ,− ...…”

“…In addition, 2D ferroelectric materials have been theoretically predicted but still challenging in the observation of stable and switchable polarization states along in-plane and out-of-plane nanostructured layers that need more time to overcome, particularly when integrating with other materials (0D, 1D, 2D, and 3D) to break the performance limits. Recently, 2D ferroelectric (e.g., VOI 2 , VOBr 2 , VOCl 2 , VOF 2 , MoTe 2 , In 2 Se 3 , SnSe) and multiferroic (e.g., TiOI 2 , VOI 2 , CrOI 2 , perovskite bilayer, Fe-doped In 2 Se 3 ) materials have been discovered and are emerging as new 2D materials for high-density multifunctional nanoelectronic devices/systems. ,,,,− Typically, new VOF 2 ferroelectric material has been theoretically predicted with the highest in-plane polarization (332 pC/m) among ferroelectric compounds, or the multiferroic materials have exhibited the coexistence of d-electron ferroelectricity and magnetism properties …”

Nonvolatile electrical control of valley splitting by ferroelectric polarization switching in a two-dimensional AgBiP2S6/CrBr3 multiferroic heterostructure

“…2D ferroelectric (FE) materials such as CuInP 2 S 6 , 31 SnSe, 32 PbTiO 3 , 33 and In 2 Se 3 34 have bistable polarization states (upward P+ and downward P− polarization states), and the direction of electrical polarization is completely opposite. 35 Switching between two different electrical polarization states can be achieved by applying an electric field, and it is nonvolatile. Even if the external electric field is removed, its electric polarization state can still be well maintained.…”