Self-assembled growth and enhanced blue emission of SiOxNy-capped silicon nanowire arrays

Unique structured SiOxNy-capped Si nanowire arrays were fabricated via electroless metal deposition on α-SiOxNy-covered Si wafer in ionic silver HF solution through selective chemical etching. A self-assembled localized microscopic electrochemical cell model and a diffusion-limited aggregation process are associated with the formation of the SiOxNy-capped Si nanowire arrays. An enhanced blue photoluminescence band has been recorded. Emission and excitation spectral analyses suggest that generation of photoexcited carriers takes place mainly in the quantum confined Si nanowires, whereas their radiative recombination occurs in the Si–N binding states of SiOxNy nanocaps.