Facile fabrication of porous silicon nanowires using water-based polyvinyl alcohol/silicon tetraacetate solution

Abstract

The fabrication of porous silicon nanowires has been studied for various applications such as lighting-emitting diodes, photovoltaics, and energy storage devices. A water-based spinning dope containing polyvinyl alcohol (PVA) and silicon tetraacetate precursor was electrospun to form nanowires, in which the silicon precursors were supported by PVA back-boned chains. The fabricated nanowires were calcined in an air furnace in order to remove the PVA polymer from the as-spun nanowires and form a silicon oxide nanowire. To reduce the silicon oxide nanowires, they were exposed to a magnesium vapor in a high-level vacuum (10−4torr) at high temperatures of 650–1100°C, followed by 0.5–3.0M HCl treatment to remove the formed MgO crystals in the reduced nanowires. The fabricated nanowires exhibited porous/linear structures with diameters ranging from 100nm to 300nm. This facile technique is suitable to mass-produce porous silicon nanowires for use in the various applications.