Researchers are racing to develop black silicon solar cells with higher and higher efficiencies – and Aalto University and the Fraunhofer Institute for Solar Energy Systems (ISE) just took the lead away from the U.S. Department of Energy’s National Renewable Energy Lab (NREL). Aalto University and Fraunhofer ISE’s new black silicon cells tout a solar efficiency of 18.7%, beating out NREL’s previous efficiency record of 18.2%.
In a paper presented at the 3rd International Conference on Crystalline Silicon Photovoltaics, scientists at Aalto University and Fraunhofer ISE reported that they were able to achieve a record efficiency for black silicon solar cells using a new “passivation” method. According to Aalto university, “researchers were able to apply a boron diffusion to create a pn-junction, maintaining the excellent optical properties of the black silicone structure. By applying atomic layer deposited AI203, an effective passivation of the nanostructured surface was achieved.”
This new method is very promising and it could yield even higher efficiencies. According to Assistant Professor Hele Savin of Aalto University, “the quantification efficiency measurements reveal that the nano structured front surface is of a high electrical quality comparable to a pyramidal textured surface.” The scientists are already looking at ways to improve their process to achieve efficiencies well above 20%.