Radial growth of zinc oxide nanowire for piezoelectric nanogenerator application

摘要

Nano- and micro-self-biased sensors employed environmental harvested energy,which are provided by different methods,such as piezoelectric.Piezoelectric materials are capable of producing electrical energy from environmental mechanical force.In this paper,a radial layer of well-arrayed hexagonal zinc oxide nanowires is grown on carbon fiber substrate using a two-step Chemical deposition method of metal salt growth.The resulted morphology is examined using Field Emission Scanning Electron Microscopy (FESEM) micrographs and X-ray Diffraction (XRD) pattern which indicates the quality and the crystallization order of the samples.In addition,composition of the material is studied using a Fourier Transform Infrared (FTIR) spectroscopy method.The results show that zinc oxide nanowires are well managed in vertical direction on the cylindrical carbon fibers.The hexagonal nanowires are grown with a length from 206 to 286 nm (Nanometer) and the diameter from 75 to 103 nm.The results of FTIR spectroscopy and XRD also illustrate the wurtzite structure of zinc oxide.The synthesized nanowires are then applied in a flexible capacitive piezoelectric nanogenerator consisting of a thin Ag layer as the upper contact and a carbon substrate as the back contact which are separated by a PMMA dielectric film.The output current and voltage are measured by applying a random pulse mechanical force on the upper contact.A maximum voltage and current of 14 mV (millivolt) and 20 nA (nanoampere) are generated at the output of nanogenerator,respectively.