In Situ Polarized Ultrathin PVDF Film-Based Flexible Piezoelectric Nanogenerators

We report a flexible, ultrathin, and compact poly(vinylidene fluoride)-based self-polarized piezoelectric nanogenerator via an expeditious quenching approach of the active layer. The appearance of the beta phase of PVDF after quenching resulted in its applicability in energy harvesting. The employed organic solvents during the fabrication process contributed to the observance of the beta phase, which is confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. A two-step approach fabrication of the PVDF device showed exceptional performance, resulting in an open-circuit peak-to-peak voltage of 19.2 V upon human hand pressing and short-circuit current >0.7 mu A. Also, the average d(33) value for the quenched PVDF film is observed to be -15.16 +/- 5.81 pm/V. Further, charging of a capacitor and powering the liquid crystal displays (LCDs) are realized through the nanogenerator, thus validating mechanical energy conversion, storage, and powering applications.