Robust Nanogenerator Based on Vertically Aligned ZnO Nanorods Using Copper Substrate

We report the growth of well-aligned ZnO nanorods that were successfully synthesized on copper (Cu) substrate by using a simple hydrothermal method at low temperature leading to a robust large area nanogenerator (NG) based on cost effective Cu electrode which could enable energy harvest from the walking motions. First, the seed layer of gold (Au) has been deposited by plasma sputtering. Then, the growth process of nanorods was carried out in a sealed chemical bath. The lengths of nanorods 5-6 μm were achieved. The longer and bigger nanorods produced a surface with larger contact area and higher roughness. The larger contact area improves the absorption rate of incident light and the rougher surface strengthens the scattering effect. The surfaces were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX). Then, Cu substrate was used for the development of high-output NG. Twenty-seven NGs were developed with maximum output voltage that exceeded to 1.8 V and maximum output current that exceeded to 148 nA. The structural simulation of nanorod has also been performed in ANSYS. The Cu substrate-based NG provides a feasible technique for effectively converting mechanical energies to electrical energy from external force.