Double layer antireflection coating for high-efficiency passivated emitter silicon solar cells

Recent high-efficiency silicon solar cells employ high-quality oxides both for surface passivation and as a rudimentary antireflection coating. This gives over 3% reflection at the cell front surface, even though the surface is microstructured. A double layer antireflection coating applied to cells with reduced SiO₂ thickness reduces the cell reflection. However, although reflection is minimized by reducing the oxide thickness to values below 100 Å, a rapid falloff in both open-circuit voltage and short-circuit current is observed experimentally once this thickness is reduced below 200 Å. The best compromise is found when oxide thickness is 250 Å which allows improved short-circuit current density without appreciable loss in open-circuit voltage