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 Ba0.85Ca0.15Ti0.90Zr0.10O3 (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 (Pr), 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 (Pmax) of 106 μC cm−2 and Pr of 12.9 μC cm−2, whereas the measured Pmax and Pr 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.