Abstract
Herein the fabrication and characterizations of self-poled, tri-layer piezoelectric nanogenerators (PENGs) have been investigated. The tri-layer structure was obtained by sandwiching surface modified n-type reduced graphene oxide (n-rGO) layer between poly(vinylidene fluoride)-barium titanate (PVDF-BTO) sheets. The highly charged n-rGO layer facilitates in improving the crystallinity of PVDF by attracting and aligning the dipoles from lower and upper PVDF-BTO sheets without any external electric field. The enhancement in electro-active beta (β) phase of PVDF was also confirmed through X-ray diffraction pattern. For the comparison analysis three different, single layer (PVDFBTO), bi-layer (n-rGO/PVDF-BTO), and tri-layer (PVDF-BTO/nrGO/PVDF-BTO) NGs were prepared. Among them, tri-layer NG reveals maximum open circuit voltage of 10 Vpk-pk. Furthermore, it exhibits short circuit current of 2.5 μApk-pk at an applied force of 2N. Finally, the mechanical stability of fabricated NG was also tested under several pressing and releasing cycles. It was estimated that our fabricated PENG can be a promising building block for powering flexible small electronics.