Optically optimal wavelength-scale patterned ITO/ZnO composite coatings   for thin film solar cells
  A methodology is proposed for finding structures that are, optically speaking, locally optimal : a physical analysis of much simpler structures is used to constrain the optimization process. The obtained designs are based on a flat amorphous silicon layer (to minimize recombination) with a patterned anti-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers. 
Antoine Moreau, Rafik Smaali, Emmanuel Centeno, Christian Seassal   (INL, ECL)
physics.optics