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

We report the 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 hours. The ZnO nanosheets were characterized for their morphology, crystallinity, and photoluminescence property. The nanogenerator is fabricated with a double-side coated aluminum substrate and compared its performance with a 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 a double side coating produced an output voltage of ~ 285 mV. The nanogenerator with double-side coating produced ~1.7 times larger voltage output compared to the voltage output from one side coated nanogenerators fabricated with each side of the substrate. The enhancement in the output