Structural and Electrical Properties of Zinc Oxide Nanostructures for Energy Harvesting Applications

Abstract

Nanostructured electronic devices are expected to facilitate the continuing miniaturization of electronic devices and enable energy harvesting device operation. In particular, one-dimensional (1D) nanostructures such as nanowire (NW) have attracted great interest over the past decade because of their specific physical properties and their potential as building blocks for next generation nano-electronic devices. Among various 1D materials, zinc oxide (ZnO), which has a direct and wide band gap, is a promising candidate for light-emitting diodes, UV / gas sensors, transistor channels, and other devices that can utilize the unique vertical alignment characteristics and highly ordered single crystalline properties of NW structures. Various type of ZnO nanowires synthesized by hydro-thermal process were examined to drive piezoelectricity for nanogenerator (NG) device. The ZnO nanwires length: (1.5 μm) were synthesized via a hydrothermal method with zinc nitrate hexahydrate and hexamethylenetetramine (HMT) on ZnO seed layers, where the 50 nm thick ZnO seed layers were deposited with a magnetron sputtering-based method. To grow different type of ZnO nanowires, a little different method was used to control carrier concentration of the ZnO nanowires. Having p-type characteristic ZnO nanowires were synthesized by adding a group-I element reagent. The structural, optical, and electrical properties of different type of ZnO nanowires were investigated by utilizing x-ray diffraction, scanning electron microscopy, transmission electron microscopy, low temperature photoluminescence, and I-V measurements.