Enhanced energy storage performance of PZT homostructure with multiple gradients distribution

Dielectric capacitor possesses an ultrahigh power density, but its relatively low energy density restricts the application. A bottleneck for enhancing the energy density originates from the contradiction between polarization and breakdown strength. Heterostructure is a routine to balance the two parameters. Here a Pb(Zr _0.52 Ti _0.48 )O ₃ (PZT) homostructure has been designed by utilizing the suppression effect of Ce doping on crystallization of PZT thin film, which exhibits with multiple gradients distribution including composition, crystallinity, and dielectric constant between layers. A high recoverable energy density of 81.3 J/cm ³ is obtained with a high breakdown electric field of 6.92 MV/cm in the homostructure. The comprehensive performance is superior to those of single layer films and some previous reported PZT multilayers. The dielectric and breakdown properties were investigated by series model and finite element method, respectively. The results suggest that the phase gradient engineering would provide a potential route to enhance dielectric energy storage density of multilayer thin films.