Monitoring Seed Formation Dynamics of Bulk-Nucleated Vapor–Solid–Solid Germanium Nanowires via Resistance Measurements

Abstract

Nanowire growth from 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 toward large-scale continuous nanowire fabrication. We present a novel method to probe nanowire nucleation and growth by in situ monitoring of the resistance of the thin film from which nanowires form. 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, and optical microscopy. The in situ resistance characterization method introduced in this paper provides new physical insight into the nanowire growth mechanism and relationship between grain coarsening and nanowire nucleation.