Fabrication and characterization of polycrystalline silicon nanowires with silver-assistance by electroless deposition

▶ In the present work, we presented a facile fabrication process of polycrystalline silicon nanowires, and studied their surface chemical composition and bonding. The surface dangling bonds of as-etched silicon nanowire arrays are saturated by silver and hydrogen. ▶ After immersion in concentrated HNO3 aqueous solution, silicon nanowires can be passivated by oxygen. The photoluminescence spectra of silicon nanowires show red light emissions centered around 700 nm. The oxygen-passivated porous silicon nanowires show much higher photoluminescence intensities than the silver/hydrogen-passivated ones. ▶ The influences of surface chemical states on the wettability of silicon nanowire arrays were also studied. ▶ We obtained a superhydrophobic surface on the as-etched silicon nanowire arrays without surface modification with any organic low-surface-energy materials, and realized the evolution from superhydrophobicity to superhydrophilicity via surface modifications with HNO3 solutions.