High Energy Storage Performance of Opposite Double‐Heterojunction Ferroelectricity–Insulators

Abstract In this study, the excellent energy storage performance is achieved by constructing opposite double‐heterojunction ferroelectricity–insulator–ferroelectricity configuration. The PbZr 0.52 Ti 0.48 O 3 films and Al 2 O 3 films are chosen as the ferroelectricity and insulator, respectively. The microstructures, polarization behaviors, breakdown strength, leakage current density, and energy storage performance are investigated systematically of the constructed PbZr 0.52 Ti 0.48 O 3 /Al 2 O 3 /PbZr 0.52 Ti 0.48 O 3 opposite double‐heterojunction. The ultrahigh electric field breakdown strength (≈5711 kV cm −1 ) is obtained, which is beneficial to achieve high energy storage density. Meanwhile, the high linearity of hysteresis loops with low energy dissipation is obtained at a proper annealing temperature, which is induced by partially crystallized and is in favor of achieving high energy storage efficiency η. The PbZr 0.52 Ti 0.48 O 3 /Al 2 O 3 /PbZr 0.52 Ti 0.48 O 3 annealed at 550 °C exhibits excellent energy storage performance with a storage density of 63.7 J cm −3 and efficiency of 81.3%, which is ascribed to the synergetic effect of electric breakdown strength ( E BDS = 5711 kV cm −1 ) and the polarization ( P m – P r = 23.74 µC cm −2 ). The proposed method in this study opens a new door to improve the energy storage performance of inorganic ferroelectric capacitors.