Controlling microstructure and film growth of relaxor-ferroelectric thin films for high break-down strength and energy-storage performance

The relaxor ferroelectric Pb_0.9La_0.1(Zr_0.52Ti_0.48)O₃ (PLZT) thin films were deposited using pulsed laser deposition, and their microstructures, break-down field strengths and energy storage performances were investigated as a function of the buffer layer and electrode. A large recoverable energy-storage density (U _reco) of 23.2J/cm³ and high energy-storage efficiency (η) of 91.6% obtained in the epitaxial PLZT film grown on SrRuO₃/SrTiO₃/Si are much higher than those in the textured PLZT film (U _reco =21.9J/cm³, η =87.8%) on SrRuO₃/Ca₂Nb₃O₁₀-nanosheet/Si and the polycrystalline PLZT film (U _reco =17.6J/cm³, η =82.6%) on Pt/Ti/SiO₂/Si, under the same condition of 1500kV/cm and 1kHz, due to the slim polarization loop and significant antiferroelectric-like behavior. Owing to the high break-down strength (BDS) of 2500kV/cm, a giant U _reco value of 40.2J/cm³ was obtained for the epitaxial PLZT film, in which U _reco values of 28.4J/cm³ (at BDS of 2000kV/cm) and 20.2J/cm³ (at BDS of 1700kV/cm), respectively, were obtained in the textured and polycrystalline PLZT films. The excellent fatigue-free properties and high thermal stability were also observed in these films.