Enhanced output performance of sandwich-type ZnO piezoelectric nanogenerator with adhesive carbon tape

Abstract

In this paper, we present a highly durable and energy-efficient sandwich-type zinc oxide (ZnO) piezoelectric energy harvesting nanogenerator, consisting of symmetrically stacked layers of ZnO/carbon tape/ZnO (ZCZ). The sandwich-type ZnO/carbon tape/ZnO nanogenerator (ZCZ-NG) devices were fabricated in a cost-effective way by depositing ZnO layers on indium tin oxide (ITO)-coated polyethylene naphthalate (PEN) substrates in a radio frequency (RF) magnetron sputtering system to form ZnO/ITO/PEN-stacked blocks as well as using a conductive double-sided adhesive carbon tape to bond two ZnO/ITO/PEN blocks together, appreciably reducing the overall fabrication time and processing steps. The output voltage and current of the fabricated ZCZ-NG devices were measured for various bending strain rates, device sizes and thicknesses of ZnO layers, generating up to about 30 V in terms of the peak-to-peak output voltage, which is much higher than those of other similar sandwich-type piezoelectric nanogenerators we reported earlier. Moreover, the output voltage variations of various ZCZ-NG devices due to their ZnO thicknesses, bending strain rates and device sizes were investigated through the observation of their output voltages.