Diatoms Could Triple Solar Cell Efficiency

Dye-sensitised solar cells work by absorbing photons on an inexpensive thin-film composed of dye molecules attached to a titanium oxide layer on a glass or plastic substrate. When the dye molecules absorb a photon, the resultant excitation injects electrons into the titanium, which transports them to the negative electrode. Dye-sensitised solar cells are favored as a thin-film material because they work in low-light conditions and are fabricated with environmentally benign materials compared to silicon solar cells. However, silicon cells have more than twice the efficiency, as much as 20 percent compared to less than 10 percent for dye-sensitised solar cells. If diatoms could triple the efficiency of dye-sensitised solar cells, they could potentially offer comparable efficiency at a lower cost, especially in low lighting conditions