Reflectivity of porous-pyramids structured silicon surface

The antireflection of porous-pyramids structured silicon surface has been studied. The porous surface is formed by stain etching in HF/Fe(NO3)3 aqueous solution after textured in KOH/IPA solution. Reflectivity measurements show an overall reflectance of 4.2% for porous-pyramids textured silicon surface in the range from 400 to 900 nm. An optimal etching time of 30 min is obtained when both reflectivity and photo-generated carriers lifetime are considered. This technique may be probably used in the texturization process for high-efficiency silicon solar cells.