Tunable antiferroelectric-like polarization behavior and enhanced energy storage characteristics in symmetric BaTiO3/BiFeO3/BaTiO3 heterostructure

The excellent energy storage performances of dielectric materials, a high energy density and efficiency, the stability in a wide range of temperature, frequency and cycling time, are surely desirable for the energy storage devices. A trade-off relationship between polarization and breakdown strength, however, limits the enhancement of energy storage properties of dielectric materials. To effectively boost the energy density and efficiency of dielectric capacitors, by inserting a BiFeO3 layer into the BaTiO3 film in present case, the symmetric BaTiO3/BiFeO3/BaTiO3 tri-layer film heterostructure with antiferroelectric-like characteristics was constructed based on the dual-interlayer coupling effect, what's more, its antiferroelectric-like characteristics will evolve with electric field. Such the tunable polarization behavior endows it with an enhanced maximum polarization but a reduced remnant one, a delayed saturation of polarization and a high breakdown strength, which are synergistically accountable for a large energy density (Wrec∼109 J/cm3) and a high efficiency (η∼82.6%), together with the good thermal (TR∼200 °C, ΔWrec<3% & Δη<10%) and frequency (50 Hz–10 kHz, ΔWrec<7% & Δη<13%) stabilities, particularly an outstanding cycling reliability (109 cycles, both ΔWrec and Δη<1%). Hence these findings can provide some innovative ideas for enriching the performance tuning of ferroelectrics, especially in enhancing their energy storage characteristics.