Binary Compound Bilayer and Multilayer with Vertical Polarizations: Two-Dimensional Ferroelectrics, Multiferroics,...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Vertical ferroelectricity in 2D materials is crucial for advanced data storage but is hindered by surface-depolarizing fields.
• Existing 2D ferroelectric materials often lack the desired vertical orientation.

Purpose of the Study:

• To investigate the potential for achieving vertical ferroelectricity in 2D materials through interlayer translation.
• To explore the multiferroic properties and energy harvesting capabilities of these materials.

Main Methods:

• First-principles calculations were employed to study various 2D material bilayers.
• Analysis focused on interlayer translation, electromechanical coupling, and Moire superlattice formation.

Main Results:

• Vertical ferroelectricity was demonstrated in 2D materials like BN, AlN, ZnO, MoS2, and GaSe via interlayer translation.
• Bilayer ferromagnets exhibited multiferroic properties with switchable magnetization.
• Electromechanical coupling enables nanogenerator applications, and Moire superlattices create tunable doping domains.

Conclusions:

• Interlayer translation is a viable mechanism for inducing vertical ferroelectricity in diverse 2D materials.
• These materials offer promising avenues for high-density data storage, energy harvesting, and novel electronic devices.
• Multilayered structures, such as ZnO, show enhanced vertical ferroelectricity.