Unipolar and bipolar fatigue in antiferroelectric lead zirconate thin films and evidences for switching-induced charge injection inducing fatigue

TL;DR

This study demonstrates unipolar fatigue in antiferroelectric lead zirconate thin films, revealing that switching-induced charge injection is a key factor in polarization fatigue, with unipolar fatigue being less severe than bipolar fatigue under similar conditions.

Contribution

First experimental evidence of unipolar fatigue in antiferroelectric capacitors and analysis of switching-induced charge injection as the primary fatigue mechanism.

Findings

Unipolar fatigue occurs in antiferroelectric capacitors.

Unipolar fatigue is less severe than bipolar fatigue at similar field magnitudes.

Switching-induced charge injection is identified as the main cause of polarization fatigue.

Abstract

For the first time, we show that unipolar fatigue does occur in antiferroelectric capacitors, confirming the predictions of a previous work [Appl. Phys. Lett., 94, 072901 (2009)]. We also show that unipolar fatigue in antiferroelectrics is less severe than bipolar fatigue if the driving field is of the same magnitude. This phenomenon has been attributed to the switching-induced charge injection, the main cause for polarization fatigue in ferroelectric and antiferroelectric materials. Other evidences for polarization fatigue caused by the switching-induced charge injection from the nearby electrode rather than the charge injection during stable/quasi-stable leakage current stage are also discussed.