Energy storage properties of low concentration Fe-doped barium strontium titanate thin films

Ba0.7Sr0.3FexTi1−xO3 (x = 0, 0.004, 0.008, 0.01, 0.015) ceramic thin films were prepared on platinized silicon wafers via sol-gel deposition method. Significant enhancement of grain size and dielectric constant were observed when x<0.008, accounting for effectively enhanced polarization, and beneficial for the energy storage applications. Excessive iron doping resulted in reduced grain size and deteriorated energy storage properties. The optimal energy storage behavior was achieved in samples with x=0.008, exhibiting a high discharged energy density of 7.6 J/cm3.