Enhanced breakdown strength of ferroelectric–dielectric multilayered thin films by blocking oxygen vacancies through linear dielectric layer

In this work, to study the influence of heterogeneous interface on electrical performance and energy storage performance, the A-doped (Ba_0.85Sr_0.15TiO₃) film was prepared on the platinum substrate by the Sol–Gel method, and a liner dielectric strontium titanate layer is inserted into different positions of the film. The linear dielectric layer (strontium titanate, SrTiO₃) can effectively block oxygen vacancies from moving towards the electrode, the experimental results show that the insertion of the liner dielectric layer notably improves insulation property. As the breakdown field strength markedly increased, the energy storage density improved as a whole. The film of Pt/ Ba_0.85Sr_0.15TiO₃/SrTiO₃ structure displays the best performance, showing energy storage efficiency is 59.1% and the energy storage density is 44.1 J cm⁻³ under 3560.3 kV cm⁻¹. In addition, the film capacitor of this structure can work stably in the temperature range of 0~100 °C. The results have provided an innovative way which can be used to selection of proper architecture of high storage efficiency capacitors.