Revealing the effect of the Schottky barrier on the energy storage performance of ferroelectric multilayers

Different from most of the studies on dielectric energy storage thin films, which mainly talk about domain engineering or interface engineering, our work revealed the effect of the interaction between film and bottom electrode on the energy storage performance of ferroelectric multilayers by fabricating multilayers of BaTiO₃ (BT) and SiO₂-BaZr_0.2Ti_0.8O₃ (S-BZT) with different layer sequences. With the same periodic number, the multilayers start with the S-BZT layer always have higher voltage endurance, and thus higher energy storage capacity(W_rec), than the multilayers start with BT. The highest W_rec was finally obtained to be 39.37 J/cm³ in BT/S-BZT//(2PN). Such a phenomenon was revealed to be related to the Schottky barrier, which was thought to be caused by the formation of the 2Ti³⁺-V_O. dipoles, in the interface between the LSMO and the S-BZT. Such an assumption was finally proved by the combination of the I-E curves and the C-E curves, and the finite element simulation was also carried out to simulate the electric breakdown process. The result of the simulation fit very well with the experimental result. The reliability and power density of BT/S-BZT//(2PN) are also good. After all, our work opens up a new way to improve the energy storage capacity of dielectric thin films. In addition, the reliability and charge-discharge behavior of the BT/S-BZT//(2PN) is also in good performance.