Formation of aligned silicon nanowire on silicon by electroless etching in HF solution

It was demonstrated that the etching in HF-based aqueous solution containing AgNO3 and Na2S2O8 as oxidizing agents or by Au-assisted electroless etching in HF/H2O2 solution at 50 °C yields films composed of aligned Si nanowire (SiNW). SiNW of diameters ∼10 nm were formed. The morphology and the photoluminescence (PL) of the etched layer as a function of etching solution composition were studied. The SiNW layers formed on silicon were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and photoluminescence. It was demonstrated that the morphology and the photoluminescence of the etched layers strongly depends on the type of etching solution. Finally, a discussion on the formation process of the silicon nanowires is presented.