Sharpening Si nanocrystals on the bulk surface by nanoscale electrochemistry through controlling the hole current with the irradiation of near-infrared laser

Numerous Si nanocrystals on the bulk surface can be efficiently sharpened by a HF-based electrochemical etching with the irradiation of near-infrared (NIR) laser simultaneously. Under the NIR laser-irradiation, the electrons excited from the B-Si complex inhibited the growth of the anodized layer and promoted the formation of nanocrystals by controlling the number of holes that participate in anodization. The effect of NIR laser-irradiation enhanced the photoluminescence by 7-10 times as compared to that obtained when anodization was performed in the dark for growing a normal porous silicon. The transmission electron microscopy images showed clearly that that nanocrystals (<3 nm) were embedded at the interface of the bulk surface and the anodized layer.