At Dimes, PhD student Andrea Ingenito has pulled out all the stops in order to use a thin solar cell to extract as much energy as possible from light. He has achieved 99% of the theoretical limit. With a width of 20 micrometres, the solar cell was about ten times thinner than usual. Special measures are therefore required to capture all of the light. For example, the front side is covered in sharp points that capture all of the light (‘black silicon’). The back side is equipped with pyramids that have a reflective layer that prevents the light from escaping.