Manufacturing aspects of oxide nanowires

Exploring the mass manufacturing aspects of nanostructures can enable the transition from laboratory-based research into a commercial product. Among the several one-dimensional nanostructures, oxide nanomaterials have a wide variety of applications including energy harvesting, photonics and biosensing applications. In this article, mass manufacturing aspects of bottom-up grown silica nanowires on silicon (Si) by metal thin film catalysis have been detailed. The investigation reports on (a) a growth model derived from studying nanowire nucleation as a function of heating time, (b) nanowire growth rate estimation via weight differential of the Si substrate before and after growth, and (c) reusability of the Si substrate for nanowire growth.Silica nanowires were found to grow on Pd coated Si substrate in an open tube furnace at 1100 °C with Ar as a carrier gas and a Si support wafer. Nanowires nucleated following a combination of Vapor Liquid Solid (VLS) and Oxide Assisted Growth (OAG) mechanisms conducive for mass manufacturing. The role of SiO vapor was found to be critical in the growth of the wires. Further, five distinct growth regimes were identified while estimating the growth rate. Experimental observations indicated the non-reusability of the Si substrate after one time growth due to depletion of catalyst.