Large energy storage density performance of epitaxial BCT/BZT heterostructures via interface engineering

We grew lead-free BaZr_0.2Ti_0.8O₃ (BZT)/Ba_0.7Ca_0.3TiO₃ (BCT) epitaxial heterostructures and studied their structural, dielectric, ferroelectric and energy density characteristics. The BZT/BCT epitaxial heterostructures were grown on SrRuO₃ (SRO) buffered SrTiO₃ (STO) single crystal substrate by optimized pulsed laser deposition (PLD) technique. These high-quality nanostructures exhibit high dielectric permittivity (∼1300), slim electric field-dependent polarization (P-E) curve with high saturation polarization (∼100 µC/cm²) and low remnant polarization (∼20 µC/cm²) through interface engineering to develop new lead-free ferroelectric system for energy storage devices. We observe an ultrahigh discharge and charge energy densities of 42.10 and 97.13 J/cm³, respectively, with high efficiency, which might be highly promising for both high power and energy storage electrical devices.