Aalto University researchers have developed a black silicon photodetector that has reached above 130% efficiency. Thus, for the first time, a photovoltaic device has exceeded the 100% limit, which has earlier been considered as the theoretical maximum for external quantum efficiency.

“When we saw the results, we could hardly believe our eyes. Straight away we wanted to verify the results by independent measurements,” says Prof. Hele Savin, head of the Electron Physics research group at Aalto University.

The independent measurements were carried out by the German National Metrology Institute, Physikalisch-Technische Bundesanstalt (PTB), which is known to provide the most accurate and reliable measurement services in Europe.