Large recoverable energy storage density and efficiency in PbZrO3-xSrTiO3 thin films with polymorphic nanodomains

PbZrO3-xSrTiO3 solid solution thin films were designed and fabricated by a metal organic decomposition method, and their structural, ferroelectric, and energy storage characteristics were investigated systematically. It is found that the incorporation of SrTiO3 not only gradually transforms PbZrO3 from antiferroelectrics to relaxor ferroelectrics but also obviously increases its breakdown strength. Large ferroelectric polarization and electric-field-dependent effective permittivity are obtained in the PbZrO3-0.4SrTiO3 thin film due to the coexistence of rhombohedral (R), tetragonal (T), and orthorhombic (O) polymorphic nanodomains and polar clusters, which results in simultaneously improved recoverable energy storage density (Wrec ∼73.7 J/cm3) and efficiency (η ∼72%). Moreover, excellent temperature stability (the variations of Wrec and η are both less than 5% as temperature increases from 243 to 393 K) and distinguished fatigue endurance (the variations of Wrec and η are both less than 1% after 108 cycles) are realized in a PbZrO3-0.4SrTiO3 thin film. This study provides a feasible alternative method for designing energy storage materials based on antiferroelectrics.