Strong Room-Temperature Visible Photoluminescence of Amorphous Si Nanowires Prepared by Electrodeposition in Ionic Liquids

Visible photoluminescence at room temperature is reported from the silicon nanowires prepared by electro-deposition in ionic liquids. Nanowires with diameters 110, 200, and 400 nm have been synthesized by a template-assisted electrodeposition using ionic liquid electrolytes. The obtained nanowires are amorphous in nature and possess robustness and good structural and compositional quality. The PL measurements at room temperature reveal a strong visible light emission from the 110 nm silicon nanowires. The strong and efficient red luminescence from the nanowires is found to be size-dependent and originates from the intrinsic radiative recombination and spatial confinement of carriers in the amorphous silicon nanowires with a thin surface oxide shell. The silicon nanowires with 110 nm diameter shows an exceptionally high quantum yield >25%. These light-emitting nanowires obtained through a simple alternative growth technique could find applications in future Si-based optoelectronic devices.