Rapid Solid-State Synthesis of Nanostructured Silicon

Abstract

Nanostructured silicon has recently been identified as an attractive material for a wide variety of uses from energy conversion and storage to biological applications. Here we present a new, rapid method of producing high-purity, nanostructured, unfunctionalized silicon via solid-state metathesis (SSM) in a matter of seconds. The silicon forms in a double displacement reaction between silicon tetraiodide and an alkaline earth silicide precursor. The products are characterized using powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive spectroscopy (EDS). Depending on the silicide precursor used, two different morphologies are obtained, either nanoparticles or dendritic nanowires. The variations in the morphologies are attributed to differences in the kinetics of the reactions.