The role of PN-like junction effects in energy storage performances for Ag2O nanoparticle dispersed lead-free K0.5Na0.5NbO3-BiMnO3 films

Abstract

This work designs a PN-like junction structure by introducing Ag₂O nanoparticles into lead-free 0.92K_0.5Na_0.5NbO₃-0.08BiMnO₃ solid solution films to investigate the role of PN-like junction effects in energy storage performances. It is shown that the energy storage performances are obviously improved with the energy density increasing to 65.1 J cm⁻³ from 20.1 J cm⁻³ and the efficiency to 62.6% from 50.7%. The enhancement is attributed to the formation of the depletion layer with high resistance derived from a PN-like junction structure at the interface between Ag₂O nanoparticles and matrices. The rectification effect of the high resistance region in PN-like junction improves the insulation and breakdown strength, and the internal local field derived from the high resistance region divides the macroscopic domains, which are attributed to the enhancement of energy storage performances. This work provides an alternative strategy to improve the energy storage performances by designing a PN-like junction structure.