Ferroelectricity driven-resistive switching and Schottky barrier modulation at CoPt/MgZnO interface for non-volatile memories

TL;DR

This study demonstrates ferroelectric memristors based on CoPt/MgZnO interfaces, showing resistive switching driven by polarization-induced Schottky barrier modulation, with potential applications in non-volatile memory devices.

Contribution

It provides the first experimental evidence of isothermal resistive switching in a simple binary ferroelectric semiconductor heterojunction, highlighting the role of polarization in barrier modulation.

Findings

Resistive switching observed across CoPt/MgZnO Schottky barrier.

Barrier height changed by 26.5 meV due to polarization reversal.

High-quality heterojunctions with ferroelectric properties confirmed.

Abstract

Ferroelectric memristors have attracted much attention as a type of nonvolatile resistance switching memories in neuromorphic computing, image recognition, and information storage. Their resistance switching mechanisms have been studied several times in perovskite and complicated materials systems. It was interpreted as the modulation of carrier transport by polarization control over Schottky barriers. Here, we experimentally report the isothermal resistive switching across a CoPt/MgZnO Schottky barrier using a simple binary semiconductor. The crystal and texture properties showed high-quality and single-crystal Co$_{0.30}$Pt$_{0.70}$/Mg$_{0.20}$Zn$_{0.80}$O hetero-junctions. The resistive switching was examined by an electric-field cooling method that exhibited a ferroelectric T$_C$ of MgZnO close to the bulk value. The resistive switching across CoPt/MgZnO Schottky barrier was accompanied by a change in the Schottky barrier height of 26.5 meV due to an interfacial charge increase and/or orbital hybridization induced reversal of MgZnO polarization. The magnitude of the reversed polarization was estimated to be a reasonable value of 3.0 (8.25) $\mu$ C/cm$^2$ at 300 K (2 K). These findings demonstrated the utilities of CoPt/MgZnO interface as a potential candidate for ferroelectric memristors and can be extended to probe the resistive switching of other hexagonal ferroelectric materials.