Superior energy storage performance and fatigue resistance in ferroelectric BCZT thin films grown in an oxygen-rich atmosphere

Abstract

Ferroelectric properties of chemical-solution-deposited Ba_0.85Ca_0.15Ti_0.90Zr_0.10O₃ (BCZT) thin films in the 200 nm thickness range, grown in air and oxygen-rich atmospheres, were investigated. Oxygen-processed BCZT thin films were found to have very slim hysteresis with higher polarization, lower remanent polarization (P_r), much lower coercivity and much higher dielectric breakdown strength. Those properties resulted in superior energy storage properties. Oxygen-processed BCZT thin films showed an energy storage density (ESD) of 64.8 J cm⁻³ and energy storage efficiency (ESF) of 73% at 2000 kV cm⁻¹ electric field. Apart from that, the films showed very low leakage current and improved polarization fatigue properties. Oxygen-processed virgin BCZT film displayed maximum polarization (P_max) of 106 μC cm⁻² and P_r of 12.9 μC cm⁻², whereas the measured P_max and P_r of the fatigued film after 10¹⁰ switching cycles were 105 μC cm⁻² and 13.2 μC cm⁻² respectively. BCZT thin films with high ESD and ESF at 2000 kV cm⁻¹ electric field and with excellent fatigue properties could be considered as potential candidates for low and intermediate voltage ferroelectric energy storage applications.