Bipolar resistive switching in amorphous titanium oxide thin films

TL;DR

This study explores the bipolar resistive switching mechanism in amorphous titanium oxide thin films, revealing temperature-dependent behavior and conduction mode transitions driven by oxygen vacancy movement.

Contribution

It provides new insights into the conduction mechanisms and activation energies involved in resistive switching of amorphous TiO2 films.

Findings

Bipolar resistive switching occurs above 140 K.

Two activation energies for shallow traps were identified.

Switching involves a transition from SCLC to Schottky conduction modes.

Abstract

Using isothermal and temperature-dependent electrical measurements, we investigated the resistive switching mechanism of amorphous titanium oxide thin films deposited by a plasma-enhanced atomic layer deposition method between two aluminum electrodes. We found a bipolar resistive switching behavior in the high temperature region (> 140 K), and two activation energies of shallow traps, 0.055 eV and 0.126 eV in the ohmic current regime. We also proposed that the bipolar resistive switching of amorphous TiO2 thin films is governed by the transition of conduction mode from a bulk-limited SCLC model (Off state) to an interface-limited Schottky emission (On state), generated by the ionic movement of oxygen vacancies.