Dielectric properties and energy-storage performance of (Na0.5Bi0.5)TiO3 thick films

Lead-free ferroelectric Na0.5Bi0.5TiO3 (NBT) thick films were successfully fabricated on LaNiO3/Si (1 0 0) substrates by using a polyvinylpyrrolidone (PVP)-modified sol-gel technique. The dielectric properties, energy-storage performance and leakage current characteristics were investigated in detail. At 100 kHz, the capacitance density of the NBT thick films was 295 nF/cm2. The maximum recoverable energy-storage density and efficiency of the sample were 12.4 J/cm3 and 43% at 1200 kV/cm, respectively. A low leakage current density of about 1 × 10−5 A/cm2 was also obtained at 700 kV/cm at room temperature. These results indicated that the lead-free ferroelectric NBT thick films might be the promising candidates for high energy-storage capacitors application.