Engineering Nonvolatile Polarization in 2D α-In₂Se₃/α-Ga₂Se₃ Ferroelectric Junctions

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) ferroelectrics enable device miniaturization and multifunctionality.
• Room-temperature ferroelectricity in 2D α-In2Se3 and related III-VI compounds allows for reversible spontaneous polarization at the monolayer limit.

Purpose of the Study:

• Investigate the structural stability, electrostatic potential, charge transfer, and electronic band structures of group-III selenide van der Waals (vdW) heterojunctions.
• Explore the potential of these heterojunctions for next-generation electronic and optoelectronic applications.

Main Methods:

• First-principles calculations were employed to study the properties of α-In2Se3/α-Ga2Se3 ferroelectric heterojunctions.
• Analysis included structural stability, electrostatic potential, interfacial charge transfer, and electronic band structures under different polarization configurations and strain.

Main Results:

• Parallel ferroelectric polarization (UU and NN) induces strong built-in electric fields, leading to carrier depletion at the interfaces.
• Antiparallel polarization (NU and UN) results in switchable electron and hole accumulation, enabling tunable n-type and p-type conductive channels.
• In-plane biaxial strain modulates band alignments, inducing type III-II-III and type I-II-I transitions depending on polarization configuration.

Conclusions:

• 2D group-III selenide ferroelectric vdW heterostructures offer significant potential for nonvolatile spontaneous polarization control.
• These materials are promising for developing next-generation electronics, nonvolatile optoelectronic memories, sensors, and neuromorphic computing applications.