Status of TiOx Antireflective Coating in the United States

The performance of glassed and unglassed Ti0x-coated silicon cells is compared to Si0-coated cells for coating thicknesses from 100 to 200 nm. The experiment was made on cells having initially the same quantum efficiency allowing complete separation of coating induced effects. U.S. cells only showed an adusted improvement of 2.6% for Ti0x-coatings over Si0-coatings as compared to an expected range of 4.8 to 5.5% as based on European investigations. Spectral reflectance analysis showed some destinct differences between the various cell types. This may be related to cell crystal orientation. All cells showed much higher reflectance at the minimum than predicted by theoretical analyses.