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

The relaxor ferroelectric Pb 0.9 La 0.1 (Zr 0.52 Ti 0.48 )O 3 (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 23.2 J/cm 3 and high energy-storage efficiency ( η ) of 91.6% obtained in the epitaxial PLZT film grown on SrRuO 3 /SrTiO 3 /Si are much higher than those in the textured PLZT film ( U reco = 21.9 J/cm 3 , η = 87.8%) on SrRuO 3 /Ca 2 Nb 3 O 10 -nanosheet/Si and the polycrystalline PLZT film ( U reco = 17.6 J/cm 3 , η = 82.6%) on Pt/Ti/SiO 2 /Si, under the same condition of 1500 kV/cm and 1 kHz, due to the slim polarization loop and significant antiferroelectric-like behavior. Owing to the high break-down strength (BDS) of 2500 kV/cm, a giant U reco value of 40.2 J/cm 3 was obtained for the epitaxial PLZT film, in which U reco values of 28.4 J/cm 3 (at BDS of 2000 kV/cm) and 20.2 J/cm 3 (at BDS of 1700 kV/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.