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 electrodeposition 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 u003e25%. These light-emitting nanowires obtained through a simple alternative growth technique could find applications in future Si-based optoelectronic devices.