Comparative Study On Energy Storage Performance Of Na.5bi.5(Ti,W,Ni)O-3 Thin Films With Different Bismuth Contents

Bi.5+delta Na.5(Ti.96W.01Ni.03)O-3 thin films with various Bi contents (abbreviated as Bi.5+delta NTWN, delta = - 2.5, 0, 2.5, 5.0%) were successfully fabricated on indium tin oxide/glass substrates by chemical solution deposition. The influences of Bi content on the microstructure, leakage current characteristic, ferroelectric and energy storage properties are investigated in detail. All the films crystallize into the single perovskite structure without any secondary phases. The average grain size decreases from 57 nm at delta = - 2.5% to 39 nm at delta = 5.0% gradually. Compared with other three films, the Bi.525NTWN sample exhibits an obvious decrease of leakage current density. For each film, with the increasing of the applied field, the dominant conduction mechanisms are the grain boundary limited conduction, the Ohmic conduction, the space charge limited conduction and the inter-face-limited Fowler Nordheim tunneling, respectively. Owing to the large values of break-down strength and difference between the remanent polarization and maximum polarization, the Bi.525NTWN sample possesses the maximum recoverable energy storage density (65.8 J/cm(3)) and energy storage efficiency (52.9%) at 2500 kV/cm.