High‐energy storage density and excellent temperature stability in antiferroelectric/ferroelectric bilayer thin films

The antiferroelectric/ferroelectric (PbZrO3/PbZr0.52Ti0.48O3) bilayer thin films were fabricated on a Pt(111)/Ti/SiO2/Si substrate using sol-gel method. PbZr0.52Ti0.48O3 layer acts as a buffered layer and template for the crystallization of PbZrO3 layer. The PbZrO3 layer with improved quality can share the external voltage due to its smaller dielectric constant and thinner thickness, resulting in the enhancements of electric field strength and energy storage density for the PbZrO3/PbZr0.52Ti0.48O3 bilayer thin film. The greatly improved electric breakdown strength value of 2615 kV/cm has been obtained, which is more than twice the value of individual PbZr0.52Ti0.48O3 film. The enhanced energy storage density of 28.2 J/cm3 at 2410 kV/cm has been achieved in PbZrO3/PbZr0.52Ti0.48O3 bilayer film at 20°C, which is higher than that of individual PbZr0.52Ti0.48O3 film (15.6 J/cm3). Meanwhile, the energy storage density and efficiency of PbZrO3/PbZr0.52Ti0.48O3 bilayer film increase slightly with the increasing temperature from 20°C to 120°C. Our results indicate that the design of antiferroelectric/ferroelectric bilayer films may be an effective way for developing high power energy storage density capacitors with high-temperature stability.