Enhanced energy density and transmittance in Eu-doped PbZrO3 films for transparent energy storage

With the advancement of sustainable power and transparent electronics, energy storage devices are increasingly required to combine high optical transparency with excellent energy storage performance. To address this demand, we fabricated Pb 1− x Eu x ZrO 3 antiferroelectric thin films on fluorine-doped tin oxide (FTO)/glass via chemical solution deposition. By varying Eu 3+ concentration ( x = 0–0.09), we investigated its effect on microstructure, transparency, and energy storage. A recoverable energy density of 43.1 J/cm 3 and a visible transmittance of 75% are achieved in the film with x = 0.05, ranking among the best transparent antiferroelectric capacitors. These performance enhancements are attributed to three effects: the lattice contraction stabilizes the antiferroelectric phase and delays the antiferroelectric–ferroelectric transition; the grain boundary densification enhances breakdown strength and reduces light scattering; and the oxygen vacancy suppression lowers leakage current and sub-bandgap absorption. This Eu 3+ doping strategy offers a promising route for developing highly transparent energy storage components for next-generation transparent electronics.