Inversely polarised ferroelectric polymer contact electrodes for triboelectric-like generators from identical materials

Although it is known that triboelectric nanogenerators (TENGs) based on ferroelectric polymer films show better performance, the origin of this enhancement remains poorly understood. To date, it has been accepted that enhancement is observed due to shift of the effective work function of the ferroelectric polymer insulator, which in turn enhances electron transfer between the TENG electrodes. The present study reveals that this view is incorrect and, in reality, the enhancement is observed due to induction driven by piezoelectric charges. Furthermore a novel piezoelectric-electrostatic generator (PEEG) has been constructed from inversely polarised polyvinylidene films, which exhibits higher performance than TENGs for mechanical energy conversion to electricity.