High energy storage density and a reversible electrocaloric effect are simultaneously achieved in Sr0.995(Na0.5Bi0.5)0.005(Ti0.99Mn0.01)O3 amorphous thin films via polar cluster engineering.
A novel Bi0.2Sr0.7TiO3/BiFeO3 thin film prepared by sol–gel/spin coating possesses ultrahigh energy storage density, good thermal stability and excellent charge-discharge performance.