Effect of Seed Layer Cycles on ZnO Nanowires Characteristics for Piezoelectric Nanogenerator Applications

This study investigates a low-temperature and cost-effective method for fabricating ZnO-based piezoelectric nanogenerators (PENGs). The hydrothermal method is employed to grow Zinc Oxide (ZnO) nanowires on flexible Indium-Tin-Oxide coated polyethylene terephthalate (ITO-PET) substrates, predeposited with seed layer for 5, 8 and 10 seed layer cycles. The aim is to assess the effect of different seed layer cycles on the alignment and dimensions of the ZnO nanowire grown. Field-emission Scanning Electron Microscopy (FESEM) is utilized to examine the alignment and dimensions of the nanowire arrays, while energy-dispersive X-ray Spectroscopy (EDX) analyses are employed to assess the elementary compositions. The alignment of ZnO nanowires improved with an increase in the number of seed layer cycles. In addition, it is found that an increased number of seed layer cycles resulted in an increase in the average diameter of ZnO nanowires from 89.5 nm to 122.31 nm, while the length was decreased from 831.67 nm to 548.67 nm. This may be attributed to variations in grain size and crystallinity of nanoparticles on the seed layers grown. These results contribute to the understanding of the growth process of ZnO nanowires for PENG applications and hold potential for advancements in green energy harvesting technologies.