Depolarization induced III-V triatomic layers with tristable polarization states

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• The mainstream semiconductor industry requires materials with high dielectric, piezoelectric, and thermal properties for novel device applications.
• Existing silicon-compatible ferroelectrics are limited, hindering device downscaling.
• Wurtzite III-V semiconductors are typically unswitchable, limiting their ferroelectric potential.

Purpose of the Study:

• To explore nanoscale depolarization effects for enabling ferroelectricity in silicon-compatible materials.
• To identify novel two-dimensional (2D) semiconductor materials for advanced electronic devices.
• To investigate the potential of ultrathin III-V materials for nonvolatile memory applications.

Main Methods:

• First-principles calculations were employed to investigate material properties.
• Phonon spectrum calculations and ab initio molecular dynamics simulations assessed thermodynamic stability.
• Variable-composition evolutionary structure search confirmed potential synthesizability.

Main Results:

• A 2D aluminum antimonide (AlSb) sheet, three atomic planes thick, exhibits both ferroelectricity and antiferroelectricity.
• Tristate switching in 2D AlSb is coupled with a metal-semiconductor transition.
• The material demonstrates thermodynamic stability and potential for synthesis.

Conclusions:

• The enhanced depolarization field at the nanoscale can induce ferroelectricity in wurtzite III-V semiconductors.
• A novel 2D AlSb material offers dual ferroelectric and antiferroelectric properties for advanced nanoelectronics.
• A proposed 2D AlSb-based homojunction field-effect transistor enables nonvolatile multibit resistance states.