High density aligned Si nanowires synthesised using electroless etching

High density one-dimensional silicon nanowires (diameter: 50-120 nm) were grown by employing electroless etching of Si in the aqueous solution of AgNO3 and HF at room temperature. The as grown nanowires were characterised using scanning electron microscopy, high resolution transmission electron microscopy, Raman spectroscopy and photoluminescence. The Si nanowires exhibited non-linear increase in length with etching time and a tendency to coalesce with increase in etching time. The optimised combination of etching time and etchant concentration results in uniform diameter wires preferably constituted of parallel planes of Si with interplanar spacing of 0.32 nm. The signals of Raman spectroscopy and photoluminescence, emerging from these synthesised Si nanowires, also corroborate the transmission electron microscopy results by elucidating the presence of amorphous and oxide structure due to overall nanocrystallinity present in these one-dimensional high yield nanowires.