Porous silicon antireflection coating by electrochemical and chemical etching for silicon solar cell manufacturing

The formation of porous Si (PSi) antireflection coating (ARC) on n+–p multicrystalline Si solar cells has been investigated in view of its implementation at the last stage of the solar cell processing. PSi layers were formed either by electrochemical (EC) etching or by chemical stain (CS) etching and led to effective reflectivity around 13% (AM1.5). Solar cells with solar energy conversion efficiency of 13.3% and 12.6% were obtained with PSi ARC formed by EC- and CS-etching, respectively, the difference originating from a 2–3% larger short-circuit current for the EC-etched cells. Additionally, the FF was higher by 1–2% (a.v.) after PSi formation, which demonstrates that both methods are non-deleterious for the front contact quality and hence suitable for a standard solar cell process.