Optimization of BaZr0.35Ti0.65O3 ferroelectric thin films on energy storage performance by adjusting annealing duration

BaZr0.35Ti0.65O3 (BZT35) ferroelectric thin films were synthesized via the sol-gel process. The phase, morphology and energy storage performance of BZT35 films of various annealing durations were studied, and the effect of annealing duration on these properties was thoroughly discussed. The size of grains in the film increases as the annealing duration prolongs, leading to an increased polarization strength. However, the breakdown field strength descends progressively with increasing annealing duration due to the increase in surface roughness. When annealed for 30 min, the film achieves the maximum polarization difference (16.1 μC/cm2) due to smaller grain size while maintaining good crystallinity, and a large breakdown field strength (3.9 MV/cm) because of its a dense structure and smooth surface. Consequently, this sample exhibits the optimal energy storage performance (Wrec = 31.54 J/cm³ and η = 91 %). The exceptional properties of BZT35 film suggest a promising application in energy storage.