Data-Driven Discovery of High-Performance Heterobilayer Transition Metal Dichalcogenide-Based Sliding Ferroelectrics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Efficient sliding ferroelectric (FE) materials are essential for next-generation low-power nanodevices.
• Current research primarily focuses on homobilayer 2D materials, with limited exploration of heterobilayers like MoS₂/WS₂.

Purpose of the Study:

• To screen a large number of transition metal dichalcogenide (TMD) bilayer heterostructures for sliding ferroelectric properties.
• To develop a descriptor for identifying promising van der Waals heterobilayers with FE behavior.
• To discover new materials with superior performance compared to existing experimental systems.

Main Methods:

• High-throughput calculations were employed to systematically investigate the sliding ferroelectric behavior of 870 TMD bilayer heterostructures.
• A novel descriptor, the amplitude of Allen electronegativity difference (Δχ_m), was developed to predict FE properties.
• Band gaps were calculated using the HSE06 method to assess material suitability.

Main Results:

• 16 semiconducting TMD heterobilayers exhibiting interlayer sliding FE were identified, all with low switching barriers (<21 meV/f.u.).
• Ten of these identified heterobilayers outperform the experimental MoS₂/WS₂ system, demonstrating up to 10 times higher out-of-plane polarization (OPP).
• These materials possess favorable band gaps (0.60-1.80 eV) suitable for FE applications.

Conclusions:

• The study provides a robust framework for designing novel sliding ferroelectric materials based on TMD heterostructures.
• Polarization switching is influenced by stacking patterns, electronegativity, charge transfer, and electronic structures.
• The findings offer a theoretical basis for future experimental research and development of advanced nanodevices.