Supercritical Fluid–Liquid–Solid (SFLS) Synthesis of Si and Ge Nanowires Seeded by Colloidal Metal Nanocrystals


  • We thank NSF and the Welch Foundation for the financial support of this work. We also thank J. P. Zhou for assistance with the HRTEM.


Semiconductor nanowires, 5 to 20 nm in diameter and micrometers in length, appear to be promising candidates for a variety of new technologies, including computing, memory, and sensor applications. Suitable for these applications, silicon (Si) and germanium (Ge) nanowires ranging from 4 to 30 nm in diameter and micrometers in length can be produced in high temperature supercritical fluids by thermally degrading organosilane or organogermane precursors in the presence of organic-monolayer-protected gold nanocrystals. Although gas phase vapor–liquid–solid (VLS) methods can be used to produce a variety of different nanowire materials, high temperature supercritical fluids provide wire size control through nanocrystal size selection prior to synthesis, and high product yields due to the high precursor solubility.