Novel BiAlO3 dielectric thin films with high energy density

Abstract Annealing temperature is a key element affecting the electrical properties and microstructure of dielectric thin films. In this case, BiAlO3 (BA) thin films were spin-coated on the Pt/Ti/SiO2/Si(100) substrates by sol-gel method and annealed at the temperature ranging from 450 °C to 550 °C. Then the influences of annealing temperatures on the microstructure, dielectric breakdown, and ferroelectric polarization of BiAlO3 thin films were studied. A optimal recoverable energy storage density (Wreco) of 31.1 J/cm3 and efficiency of 82.2% were achieved for the BA thin films annealed at 500 °C due to the ultrahigh dielectric breakdown strength (BDS) of 3535.7 kV/cm. This study offers a new paradigm for developing high-performance lead-free dielectric materials, which can largely extend the energy storage application of Bi-base perovskite materials.