Selective Thermochemical Growth of Hierarchical ZnO Nanowire Branches on Silver Nanowire Backbone Percolation Network Heaters

The development of hydrothermal growth enabled facile growth of ZnO nanowire over a large area at mild environments, yet its usage in actual electronic devices has been restricted due to poor spatial selectivity in the growth and a difficulty in the integration to other components. We introduce a local thermochemical growth of ZnO nanowire branches on Ag nanowire backbone percolation networks by electrical current induced local resistive heating in liquid environment for easy fabrication of metal-semiconductor hierarchical nanowire structure. Through vacuum filtration transfer and laser ablation process, patterned conductive network composed of ZnO nanoparticle functionalized Ag nanowire percolation network was prepared as a conductive network for localized resistive heating. Upon the application of proper bias voltage, highly localized temperature field was generated in the vicinity of the patterned Ag nanowire network heater to induce the selective growth of ZnO nanowire from the Ag nanowire backbone. As the temperature rise is related to the electrical current flow, ZnO nanowire was selectively synthesized at the area subject to the maximum current density, which was defined by the laser ablation technique. It was further confirmed that the characteristics of grown ZnO nanowires could be controlled by changing the growth condition.