Morphology and electrical properties of high aspect ratio ZnO nanowires grown by hydrothermal method without repeated batch process

We propose a growth method to obtain ZnO nanowires with very high aspect ratios which involves adding ammonium chloride without repeated batch process. The ZnO nanowires with a length of over 13.6 μm and an aspect ratio of about 97 were grown by the proposed method. Nanogenerators based on the prepared ZnO nanowires were fabricated and their electrical properties were characterized as a function of aspect ratio to verify the changes in the piezoelectric potential. We obtained a maximum current density of ∼1.6 μm/cm2 by applying a compressive force to the nanogenerator using a linear motor.