Improving energy storage performance of sol-gel-derived PbZrO₃ thin films by adjusting the water/acetic acid solvent ratio

PbZrO₃ and PbZrO₃-based thin films as a typical antiferroelectric material have been widely studied for high-density energy storage capacitors. To prepare high-quality PbZrO₃ films by the sol-gel method, it is necessary to fully understand the effects of precursor solution on the microstructure and electrical properties of the films. In this study, the microstructure and electric properties of the sol-gel-derived PbZrO₃ thin films were studied as a function of the water/acetic acid ratio from 10/90 to 85/15 by volume in the precursor solution. The results indicate that the water/acetic acid ratio had a significant impact on the crystalline quality, microstructure, electrical properties, and energy storage performance of PbZrO₃ thin films. When the water/acetic acid ratio was relatively low, that is, 20/80, the PbZrO₃ thin films had the best antiferroelectric properties and energy storage performance. The films exhibited the well-developed hysteresis loop, with maximum polarization (P_max) and remanent polarization (P_r) of 72.55 μC/cm², and 3.71 μC/cm², respectively. Due to the larger P_max and smaller P_r, as well as enhanced electrical breakdown strength (E_BDS), the films exhibited the maximum W_rec of 21.9 J/cm³ at 1000 kV/cm. Our results demonstrate that to obtain better antiferroelectric properties and energy storage performance, it is preferable to add a low proportion of water/acetic acid in the precursor sol-gel solution.