Ultra-high energy density thin-film capacitors with high power density using BaSn0.15Ti0.85O3/Ba0.6Sr0.4TiO3 heterostructure thin films

Abstract Ultra-high energy storage performance of lead-free ferroelectric materials has been achieved at room temperature by heterostructure composite based on environment-friendly BaSn0.15Ti0.85O3 and Ba0.6Sr0.4TiO3 thin films. The dielectric constant and loss tangent of BaSn0.15Ti0.85O3 layers grown on the Ba0.6Sr0.4TiO3 layers respectively are calculated as 402 and 0.0137 at 100 kHz. The interfacial layer between BaSn0.15Ti0.85O3 and Ba0.6Sr0.4TiO3 layers can improve the dielectric constant and reduce the loss tangent of heterostructures. The electrical breakdown strength can be significantly enhanced by the interfacial layer, and the influence mechanism is proposed. Ultra-high energy storage density as high as 43.28 J/cm3, is obtained at a sustained high bias electric field of 2.37 MV/cm with a power density of 6.47 MW/cm3 and an efficiency of 84.91% in the BaSn0.15Ti0.85O3/Ba0.6Sr0.4TiO3 heterostructure thin films.