Ultrathin solar cells achieve a record of nearly 20 percent efficiency

Researchers at the Centre de Nanosciences et de Nanotechnologies (C2N), in collaboration with researchers at the German Fraunhofer ISE, have trapped sunlight efficiently in a solar cell thanks to an ultrathin absorbing layer made of 205 nm-thick GaAs on a nanostructured back mirror. This new architecture raised efficiency of the cell to nearly 20 percent.