Light-trapping structures for planar solar cells based on Schwarz-Christoffel mappings

Optimal light absorption is decisive in obtaining high-efficiency solar cells for which the current approach uses direct nanostructuring of its absorber layer. This has a detrimental impact on the electrical properties of the solar cell due to an increased surface recombination current (owing to enlarged surface area and surface defects) and due to direct patterning process itself. To mitigate these effects, this work theoretically explores a Transformation Optics (TrO) approach to map the nanopatterned textures onto its planar equivalent. This allows to achieve structures with the same optical functionality but with much improved electrical properties. Schwarz-Christoffel mappings are used for ensuring conformality of the maps thus leading to planar inhomogeneous dielectric-only materials. The practical aspects concerning a possible implementation are also discussed in this work, thus paving a way towards a novel approach for implementing light-trapping structures into solar cells.