EPFL scientists in Neuchâtel have reported a tandem solar cell that can deliver a certified efficiency of 29.2%. This achievement was made possible by combining a perovskite solar cell with a textured silicon solar cell.
One obstacle the team encountered was finding a way to evenly coat the silicon surface—which is intentionally rough, or textured—with a thin film of halide perovskites. A textured surface is used in order to minimize light reflection. This kind of system can already be found in all commercially available crystalline silicon cells.