Tolerance against conducting filament formation in nanosheet-derived titania thin films

TL;DR

This study demonstrates that nanosheet-derived titania thin films resist conducting filament formation, showing promise for dielectric applications due to their stable resistive properties and high dielectric strength.

Contribution

It introduces a novel fabrication method for titania thin films that results in poor resistive switching and high dielectric strength, differing from conventional techniques.

Findings

Poor resistive switching due to low oxygen vacancy concentration

Comparable or higher dielectric breakdown strength than conventional films

Potential suitability for dielectric applications

Abstract

Herein, titania thin films are fabricated by a facile liquid-phase method based on vacuum filtration of a colloidal suspension of titania nanosheets, which is followed by thermal annealing to transform the nanosheet film into anatase TiO2. Nanosheet-derived titania thin films exhibit poor resistive switching with an interface-type mechanism. This behaviour is distinct from the filamentary switching that has been observed with titania thin films fabricated by other conventional techniques. This tolerance against conducting-filament formation may be ascribed to a low concentration of oxygen vacancies in nanosheet-derived films, which is expected because of the O/Ti ratio of titania (Ti0.87O2) nanosheets being larger than that of TiO2. Besides, the dielectric breakdown strength of nanosheet-derived films is found to be comparable to or higher than that of titania thin films fabricated by other techniques. These findings clearly indicate the usefulness of nanosheet-derived titania thin films for dielectric applications.