Enhanced output of ZnO nanosheet-based piezoelectric nanogenerator with a novel device structure

Abstract

We report a double-fold enhancement of piezoelectric nanogenerator output voltage with a simple design strategy. The piezoelectric nanogenerator is fabricated with ZnO nanosheets coated on both sides of the aluminum substrate in this new design strategy with necessary electrodes. The cost-effective hydrothermal method is employed to synthesize two-dimensional (2D) ZnO nanosheets on both sides of the aluminum substrate at a low growth temperature of 80 °C for 4 h. The ZnO nanosheets were characterized for their morphology, crystallinity, and photoluminescence property. The performance of nanogenerator fabricated with double-side coated aluminum substrate was compared to single-side coated aluminum substrate. The nanogenerators fabricated only with one side coating produced an output voltage of ∼170 mV. In contrast, the nanogenerators fabricated with double side coating produced an output voltage of ∼285 mV. The nanogenerator with double-side coating produced ∼1.7 times larger output voltage than that of single-side coated one. The enhancement in the output voltage is mainly due to ZnO nanosheet deformation along both sides and the electric field-induced synergetic effect between two front and back sides of piezoelectric nanogenerators. This nanogenerator fabrication technology has the potential to be scaled up for industrial production of piezoelectric energy collecting devices because of its simplicity and high output gain.