Screen printed Ta2Os and TiO2 antireflection coatings for crystalline and polycrystalline silicon solar cells

Screen printable inks for Ta2O5 and TiO2 antireflection coatings have been applied to silicon wafers and characterized. On polished crystalline wafers, both coatings give near-zero minimum reflectance. The wavelength of the minimum can be easily tuned to match the solar spectrum by changing the screen mesh size. The average reflectance over the AM1 spectrum can be further reduced by texturizing the wafer surface prior to coating. Similar reflectance results are obtained for both crystalline and polycrystalline wafers, although the average reflectance is not quite as low in the latter case due to the difficulty of texturizing polycrystalline material.