High energy storage density with high power density in Bi0.2Sr0.7TiO3/BiFeO3 multilayer thin films

摘要

Ferroelectric thin film capacitors with outstanding energy storage performances and fast charge/discharge speed have aroused the attention of researchers due to the development towards the minimization and integration of advanced electronic devices. Herein, environmentally friendly Bi0.2Sr0.7TiO3/BiFeO3 multilayer thin films with different BFO layers have been designed and constructed on Pt(111)/Ti/SiO2/Si substrates by sol-gel/spin coating method. An enhanced polarization and large breakdown strength are simultaneously achieved in the 2BFO multilayer thin film caused by the synergistic effect of multiple polar structures, electric field amplifying effect and interfacial effect, which leads to an ultrahigh energy storage density of similar to 50.9 J cm(-3) accompanying an efficiency of similar to 52.84%. Moreover, the P-E loops of the 2BFO sample are ultra-stable, and no obvious deterioration of the energy storage performances is observed in the wide operating temperature ranges (35-140 degrees C). The 2BFO capacitor possesses a fast charge/discharge speed of similar to 1.5 mu s and a giant power density of similar to 45.195 MW cm(-3), which are superior to that of the commercial BOPP capacitor. The excellent energy storage characteristics make the 2BFO multilayer thin film a promising candidate for energy storage applications.