Black silicon: a new manufacturing method and optical properties

A new method for manufacturing nanostructured black silicon ($b$-Si) by growing cone-shaped (pointed) filamentous nanocrystals (nanowires, FNWs) on the surface of single-crystal Si-plates has been proposed. $b$-Si samples with reflectivity less than 0.1% have been obtained. It has been shown that the $b$-Si reflection coefficient depends on the sizes of the FNWs in the visible region of the spectrum: its minimum value (less than 0.1%) has been achieved at diameters at the base of the FNWs of 650–750 nm and a length of 1.5–2 $\mu$m.