Researchers at Aalto University have obtained a record-breaking efficiency of 22.1% on nanostructured silicon solar cells. An almost 4% absolute increase to their previous record was achieved by applying a thin passivating film on the nanostructures by Atomic Layer Deposition, and by integrating all metal contacts on the back side of the cell. The record cells consist of a thick back-contacted structure that is known to be highly sensitive to the front surface recombination. For the first time, the black silicon is not limiting the final energy conversion efficiency.
Professor Hele Savin coordinated the study, which was a joint project with Universitat Politècnica de Catalunya. In the near future, the research team aims to apply the technology to other cell structures.
"Our record cells were fabricated using p-type silicon, which is known to suffer from impurity-related degradation. There is no reason why even higher efficiencies could not be reached using n-type silicon or more advanced cell structures", Professor Savin predicts.
Read more on Aalto University’s website