Strongly enhancing the energy storage properties and stability of amorphous BaTiO3 thin films via ions doping

Amorphous thin films with high power density and breakdown strength satisfy the needs of advanced power electronic systems. Nonetheless, improving the energy storage density of amorphous films is critical for addressing the growing demand for electricity. We apply high spontaneous polarization BaTiO 3 as the main component to make (1-x)Ba(Ti 0.99 Mn 0.02 )O 3 -xBiFeO 3 ((1-x)BTM-xBF) thin films. Doping BiFeO 3 (BF) synergistically boosts polarization. The introduction of amorphous phases and Mn ions enhances the breakdown strength. The results demonstrate that, at x = 0.10, the film can achieve both a high efficiency of 80.3 % and an excellent energy storage density of 111.3 J cm -3 . Moreover, the film has a strong thermal stability within a broad range of 20 to 160 °C, as well as the cycling reliability is as high as 10 5 times. The present study offers a practical approach to develop film capacitors with outstanding energy storage capabilities.