Increased Energy-Storage Density and Superior Electric Field and Thermally Stable Energy Efficiency of Aerosol-Deposited Relaxor (Pb0.89La0.11)(Zr0.70Ti0.30)O3 Films

Abstract

(Pb0.89La0.11)(Zr0.70Ti0.30)O3 (PLZT 11/70/30) relaxor ferroelectric (RFE) films were fabricated on Pt/Si substrates by aerosol deposition, which not only enabled the deposition of a film at room temperature but also increased the dielectric breakdown strength. Perovskite phase and microstructural analyses were carried out by x-ray diffraction and scanning electron microscopy techniques. A PLZT 11/70/30 RFE AD film annealed at 550 °C exhibited the best dielectric properties (er ~ 1090, tanδ ~ 0.028) and typical relaxor-type slim polarization–electric field (P–E) hysteresis loop with relatively low remanent polarization (Pr ~ 6.81 µC/cm2) and coercive field (Ec ~ 118 kV/cm) even at a high applied electric field (~ 2500 kV/cm). These superior properties were achieved due to high phase purity, low defect densities, and well-tuned grain sizes of an annealed PLZT 11/70/30 RFE AD film. The PLZT 11/70/30 RFE AD film exhibited a high energy-storage density (Wrec ~ 44 J/cm3) which is attributed to the high dielectric breakdown strength, low hysteresis loss (Wloss ~ 10.3 J/cm3), and almost-electric-field-independent efficiency (η ~ 81%, change of ~ 6% with the change from low to high electric fields), calculated using the unipolar P–E hysteresis loop. The excellent temperature stability of the energy efficiency of the PLZT 11/70/30 RFE AD film makes it a promising material for high-temperature energy-storage capacitor applications.