Stress modulated Pb-cation displacement to strengthen polarization switching in PbZrO3 antiferroelectric films for energy storage

Abstract

Antiferroelectric films are promising electrical/thermal switch candidates due to their fast polarization switching characteristics. However, the internal mechanism of stress-modulated polarization switching in antiferroelectric films from the atomic scale is not fully understood, which limits their energy/information storage. Herein, the relationship between residual stress-induced Pb-cation displacement and polarization switching in antiferroelectric PbZrO₃ (PZO) films is comprehensively investigated. It is found that compressive stress relaxes, mobility of Pb-cation enhances, and double hysteresis loop characteristics gradually become obvious as thickness increases. The polarization switching of PZO films with high compressive stress slightly changes under external temperature- and frequency-field stimulus indicating its strong phase transition stability. For the leakage mechanism, a space charge-limited current (SCLC) for 2-layer (75-nm) and 4-layer (170-nm) PZO transforms into mixed multiple effect for other PZO films at low electric field, and the Fowler-Nordheim tunneling (FN) dominates all PZO films with further increasing electric field. This work builds a close correlation between stress-modulated Pb-cation displacement and polarization switching in PZO films and advance the research of designing new antiferroelectric materials to achieve high energy storage capability.