Light trapping in thin-fim solar cells: Gain in spite of defects

In this work, we report a nanostructure that grants a significant enhancement in optical efficiency to a thin-film solar cell based on amorphous silicon. The fabrication technique is very cheap and the nanostructure can be easily and rapidly prepared on a large area. This is possible by price of numerous mm-sized defects. In the areas of these defects the optical effciency suffers. However, the enhancement of optical effciency in the non-defective regions is so significant that the presence of defects still allows the gain granted by our light-trapping structure compared to a standard anti-reflective coating.