Enhanced energy storage performance of (Pb, La)(Zr, Ti)O3/SrTiO3 multilayer films via a synergistic strategy

Dielectric film capacitors possess a larger dielectric breakdown field than that of their bulk ceramic counterparts, thus showing a better energy density. Herein, a synergistic strategy has been employed to enhance the energy storage density of (Pb, La)(Zr, Ti)O3/SrTiO3 multilayer films through combing the effects of atomic doping, heat treatment, and multilayer stacking. La partially substituting Pb improves relaxor characteristics of Pb(Zr, Ti)O3. A dense amorphous microstructure results in a relatively high breakdown electric field at a low annealing temperature. Additionally, the insertion of dielectric layer SrTiO3 into (Pb, La)(Zr, Ti)O3 suppresses the carriers transport due to the interface role and further improves the insulating strength and breakdown strength. Thus, a high recoverable energy density of 67.1 J/cm3 is achieved at an ultrahigh breakdown electric field of 7.45 MV/cm. Such a synergistic multiscale approach in this work is universally effective to improve the energy storage performance of dielectric multilayer films.