Studies on energy storage properties of BFO/WO3 bilayer thin film capacitor

Present work reports the growth of BFO/WO3 bilayer thin film structures over Silicon, corning and ITO coated glass substrates. BFO layer in BFO/WO3 bilayer structure was deposited using Pulsed Laser deposition (PLD) technique at optimized laser energy (200 mJ) while WO3 nanostructured layer was deposited using rf-magnetron sputtering technique at varying glancing angle from 65 degrees to 80 degrees. For the realization of MBM (metal-bilayer-metal) device, top Gold (Au) electrodes have been deposited using thermal evaporation technique. The BFO/WO3 bilayer structure fabricated at 70 degrees glancing angle exhibited the saturation (P-s) and remnant (P-r) polarization as 45.45 mu C/cm(2) and 21.52 mu C/cm(2) respectively, which are appreciably higher than the earlier reports for pure BFO thin films. Enhanced energy storage characteristics were obtained in Au/BFO/WO3/ITO structure fabricated at 70 degrees glancing angle with charge-discharge efficiency (63%) and enlarged recoverable energy density (467 mJ/cm(3)). Achieved results indicate the utilization of fabricated Au/BFO/WO3/ITO structures towards high energy storage applications.