Improvement of energy storage performance in PbZr0.52Ti0.48O3/PbZrO3 multilayer thin films via regulating PbZrO3 thickness

In this work, to prepare the PbZr0.52Ti0.48O3(PZT)/PbZrO3(PZ) multilayer films, PZ films and PZT films were spin-coated on LaNiO3/SiO2/Si substrates in sequence by the sol-gel method, and the PZ films were prepared using PZ precursor solution with different concentrations. After each spin-coating, PZ layer and PZT layer were annealed with rapid thermal annealing (RTA) technique at 650 °C and 550 °C, respectively. The crystal structures, microstructures and electrical properties of the films with different PZ film thickness were comprehensively investigated. The PZ films with different thickness showed perovskite phase. The PZT films on crystallized PZ films exhibited the coexistence of pyrochlore phase and perovskite phase at the annealing temperature of 550 °C. The PZT/PZ multilayer films with 0.2 M PZ precursor solution exhibit typical anti-ferroelectricity with double hysteresis loops, while other multilayer films exhibit nearly linear loops. In addition, the recoverable energy storage density increases with the increase of the film thickness and reaches the maximum value 32.4 J/cm3 in the PZT/PZ multilayer films with 0.4 M PZ precursor solution. Therefore, the ferroelectric properties of the PZT/PZ multilayer films could be regulated by different PZ film thickness, which effectively further enhances the energy storage performance.