Boosting energy storage performance of relaxor Na0.5Bi0.5(Fe0.03Ti0.97)O3/Na0.5Bi0.5(Zr0.02Ti0.98)O3-based multilayer thin films under moderate electric field via aging & treating processing

Na0.5Bi0.5(Fe0.03Ti0.97)O-3/Na0.5Bi0.5(Zr0.02Ti0.98)O-3 (NBFT/NBZT)-based relaxor multilayer thin films are successfully prepared on Pt/Ti/SiO2/Si substrate via a sol-gel method. Abundant interfaces are brought in by periodically stacking the building block of one single unit between NBFT & NBZT to form various structures and consequentlly, high dependence of energy storage performance on the number of interface is noted. Considering the structural relaxation of the multilayers, aging and treating are taken from the prospective of improving energy storage performance at a relatively stable state. Accordingly, after aging for 21 d and treating, a relatively large recoverable energy storage density (W-rec) and an efficiency (eta) of 71.7 J/cm(3) and 74.1% are obtained, respectively at room temperature. Excellent thermal stability for W-rec and eta are also noticed with the rates of change of <= 6.5% and <= 5%, respectively for W-rec and eta from 225 to 498 K, along with the corresponding values of <= 2.0% and <= 4.2% after fatigue endurance of 10(7) cycles. These findings provide an effective way of designing NBT-based multilayer thin film for energy storage devices.