The coating is created by depositing a layer of thin, highly porous silica-based film onto the surface of a glass plate. This reduces the amount of light reflected from the surface of the glass – thereby ensuring the highest possible transmission of light and maximizing the solar power output.
Nanopores: The key to reflectivity
The key to the anti-reflective coating’s reflective properties lies in millions of nanopores that create a refractive index between the air and glass. To enable this porous structure, we created a formulation consisting of “core-shell” particles, made from a latex polymer core and a silica-based shell. In turn, a wide range of deposition methods (like roll-coating and slot-die coating) can then be used to deposit a 100-150-nanometer-thick layer onto the surface of the glass. The spaces between the core-shell particles are filled with a modified silica binder, which acts as a glue. From here it is cured, with the polymer core removed by thermal degradation to leave a silica-glass layer with a high internal porosity that can significantly reduce reflection. The end result? A solar module energy gain of 3% (measured in Flash tests).