Combined metal-assisted chemical etching and anisotropic wet etching for anti-reflection inverted pyramidal cavities on dendrite-like textured substrates

A simple and low-cost method using the combination of metal-assisted chemical etching (MacEtch) and anisotropic wet etching was performed to fabricate anti-reflection inverted pyramidal cavities on dendrite-like textured silicon substrates. To achieve this, a thin Ag film was deposited on an n-type (100) silicon substrate to form agglomerated Ag particles and MacEtch was performed to obtain vertically aligned etching holes on Si substrate. Subsequently, anisotropic wet etching was conducted and the etchant would penetrate the porous structure to form inverted pyramidal cavities on the dendrite-like structure. Using this two-step etching, excellent anti-reflection behavior was obtained for our textured substrates.