High–Energy‐Storage Density Capacitors of <scp> <scp>Bi</scp> </scp> ( <scp> <scp>Ni</scp> </scp> _1/2 <scp> <scp>Ti</scp> </scp> _1/2 ) <scp> <scp>O</scp> </scp> ₃ – <scp> <scp>PbTiO</scp> </scp> ₃ Thin Films with Good Temperature Stability

Abstract

High–energy‐storage density capacitors with thin films of 0.5 Bi ( Ni 1/2 Ti 1/2 ) O 3 –0.5 PbTiO 3 ( BNT – PT ) were fabricated by chemical solution deposition technique on Pt / Ti / SiO 2 / Si substrates. The dense thin films with pure‐phase perovskite structure could be obtained by annealing at 750°C. High capacitance density (~1925 nF/cm 2 at 1 kHz) and extremely high‐energy density (~45.1 J/cm 3 ) under an electric field of 2250 kV/cm were achieved at room temperature. The energy‐storage density and efficiency varied little in a wide temperature range from −190°C to 250°C. The high–energy‐storage density and good temperature stability make BNT – PT films promising candidates for high power electric applications.