Enhanced energy storage performance in 0.9NBT-0.1BFO thin film

Abstract Dielectric capacitors have been receiving increasing attention due to their high power density. Among the various possibilities, Bi-based perovskite ferroelectrics, such as BiFeO3 (BFO) and Na0.5Bi0.5TiO3 (NBT), are considered as potential candidates due to their superior ferroelectric properties. In this work, NBT and 0.9NBT-0.1BFO thin films have been fabricated on (0 0 1) SrTiO3 substrate, in which 0.9NBT-0.1BFO film was deposited by magnetron sputtering and pulsed laser deposition hybrid technique. The X-ray diffraction confirms that the (0 0 1) oriented 0.9NBT-0.1BFO thin film is epitaxial grown on SrTiO3 substrate. Enhanced energy storage performance, with recoverable energy density of 44 J/cm3 and high thermal stability of the energy storage density (with minimal variation of ≤6%) over 40–180 °C, could be achieved in in 0.9NBT-0.1BFO film. It is revealed that the introduction of BFO leads to increased polarization up to 141μC/cm2 vs 76.4μC/cm2 for pure NBT film, which accounts for the high energy storage density. The results indicated that the 0.9NBT-0.1BFO thin-films might be promising environmentally friendly lead-free materials for energy storage applications.