Enhanced recoverable energy storage density of Mn-doped Ba0.4Sr0.6TiO3 thin films prepared by spin-coating technique

Mn-doped barium strontium titanate Ba 0.4 Sr 0.6 TiO 3 - x mol%Mn ( x  = 0, 1, 3 and 5; BSTM x ) thin films were deposited on Pt/Ti/SiO 2 /Si(100) substrates by spin-coating and annealed at 800 °C. X-ray diffraction patterns revealed that all the thin films were a typical cubic perovskite structure and no impurity peaks were observed. The effect of Mn doping on the ferroelectric properties and energy storage performance of the samples was investigated. The results showed that the recoverable energy storage density U rec and the difference ∆ P ( P max  −  P r ) between maximum polarization P max and remnant polarization P r firstly increased, then decreased with the increase of Mn doping amount. The optimized energy storage performance was obtained in Pt/BSTM3/Pt thin films: energy storage density of 8.48 J/cm 3 and energy storage efficiency of 42.4% at 1.63 MV/cm, electrical resistivity of 4.19 × 10 10  Ω cm and leakage current density of 7.77 × 10 −6  A/cm 2 at 163 kV/cm. Moreover, the effect of different top electrodes on energy storage performance was studied, which displayed that the energy density of Au/BSTM3/Pt films was higher than that of Pt/BSTM3/Pt films. The results indicated that Mn doping and Au electrodes could be effective ways to improve the energy storage properties of BST thin films.