Depolarization Induced III-V Triatomic Layers with Tristable Polarization States

TL;DR

This paper demonstrates that nanoscale depolarization fields can induce tristable polarization states in ultrathin III-V semiconductor layers, enabling novel 2D ferroelectric/antiferroelectric materials for multibit nanoelectronics.

Contribution

First-principles calculations reveal a new 2D triatomic layer of AlSb with tristable polarization states and potential for nonvolatile multibit devices.

Findings

Ultrathin AlSb layers exhibit reversible ferroelectric and antiferroelectric states.

Tristate switching causes a metal-semiconductor transition.

The proposed 2D AlSb-based FET supports three resistance states.

Abstract

The integration of ferroelectrics that exhibit high dielectric, piezoelectric, and thermal susceptibilities with the mainstream semiconductor industry will enable novel device types for widespread applications, and yet there are few silicon-compatible ferroelectrics suitable for device downscaling. We demonstrate with first-principles calculations that the enhanced depolarization field at the nanoscale can be utilized to soften unswitchable wurtzite III-V semiconductors, resulting in ultrathin two-dimensional (2D) sheets possessing reversible polarization states. A 2D sheet of AlSb consisting of three atomic planes is identified to host both ferroelectricity and antiferroelectricity, and the tristate switching is accompanied by a metal-semiconductor transition. The thermodynamics stability and potential synthesizability of the triatomic layer are corroborated with phonon spectrum calculations, ab initio molecular dynamics, and variable-composition evolutionary structure search. We propose a 2D AlSb-based homojunction field effect transistor that supports three distinct and nonvolatile resistance states. This new class of III-V semiconductor-derived 2D materials with dual ferroelectricity and antiferroelectricity opens up the possibility for nonvolatile multibit-based integrated nanoelectronics.