(167g) Monitoring Seed Formation Dynamics of Bulk-Nucleated Vapor-Solid-Solid Germanium Nanowires Via Resistance Measurements

Nanowire growth from bulk metal surfaces presents several scientifically interesting and technologically important research challenges. Scientifically, many knowledge gaps remain about the fundamental mechanism by which nanowires nucleate from bulk surfaces. Technologically, this approach presents a promising pathway towards large-scale continuous nanowire fabrication. We present a novel method to probe nanowire growth in-situ by monitoring the resistance of the substrate from which the nanowires nucleate. We show that probing the resistance of the inductively heated thin film provides real time diagnostic information about the reaction, including temperature, surface composition, and coarsening rate. We relate distinct features in the transient resistance to growth processes using ex-situ characterization via X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, optical microscopy, and contact profilometry. Using this technique, we reveal temporal intricacies of seed formation and supersaturation. We correlate the evolution of the germanide grain size to the nanowire diameter and provide guidance for diameter-specific nanowire synthesis. We extend the use of this technique to commercially scalable substrate materials. This method can enable rapid tuning of kinetic conditions of commercially scaled nanowire growth systems.