Domain-Enhanced Energy Storage, Piezoelectric, and Dielectric Properties in Pb(Zr_0.52Ti_0.48)O₃/SrTiO₃ Ferroelectric Superlattices

The domain structure and ferroelectric properties are highly sensitive to interfacial strain and electrostatic interaction in the ferroelectric superlattices. Here, we fabricated a series of [Pb(Zr_0.52Ti_0.48)O₃]_m/[SrTiO₃]₃ (PZT_m/STO₃) ferroelectric superlattices (m = 2, 3, 6... unit cells) on SrTiO₃ (001) substrates by pulsed laser deposition. Compared with pure PZT films, the energy storage density, piezoelectric properties, and dielectric constant of the superlattice are improved. Particularly, the energy storage density, which is increased by about 158%. The modulation of PZT/STO superlattice period thickness effectively improves its dielectric and relaxation properties, which in turn enhances its energy density and efficiency. The mechanism underlying the excellent energy storage properties was revealed by the formation of nanodomains analyzed by a piezoresponse force microscope. Adjusting the electrostatic interactions by changing the periodic thickness of ferroelectric superlattices provides a promising strategy for the design of high-performance sensors and energy-storage devices.