Simultaneously achieved high energy storage density and efficiency in sol–gel derived BZT thin films integrated on Si

Abstract

Among various dielectrics, ferroelectric thin films for capacitors have attracted considerable attention due to the excellent energy storage properties. In this work, the multilayered BaZr_0.35Ti_0.65O₃ (BZT) ferroelectric films were fabricated on p-type silicon substrates via a sol–gel/spin-coating processing. The microstructure and phase composition of BZT multilayer films were evaluated at variable thickness induced by different number of deposits, and their effects on breakdown strength as well as energy storage performance have been systematically investigated. The results show that BZT thin film coated at a single layer ∼ 40 nm crystallized into a dense nanocrystalline structure of the pyrochlore phase, leading to the lowered leakage current and reduced polarization switching hysteresis, while exhibiting a large energy storage density of 80.4 J/cm³ and high energy efficiency of ∼ 90 % simultaneously due to the ultrahigh breakdown strength of 7.75 MV/cm. This work provides a scalable approach towards high-performance eco-friendly ferroelectric film capacitors integrated on silicon.