Researchers in the UK and Singapore have developed a method to print ultrathin coatings on next-generation perovskite solar cells to protect them in higher efficiency tandem configurations.
A team of researchers from Cambridge’s Department of Materials Science and Metallurgy led by Professor Judith Driscoll and Dr Robert Hoye, working with Imperial College London and the Solar Energy Research Institute of Singapore, have developed a method to create a protective coating of copper oxide over the perovskite device. They have shown that a 3nm coating using vapour phase deposition is sufficient to prevent any damage to the perovskite after depositing the transparent top electrode. These devices reach 24.4 percent efficiency in tandem with a silicon cell. Their results are reported in ACS Energy Letters.
Key to success is the ability of their oxide growth method to replicate the quality of precise, vacuum-based techniques, but in open air and much faster. This minimises any damage to the perovskite when coating it with the oxide, while ensuring that the oxide grown has high density, such than only a very thin layer is needed to completely protect the perovskite. This vapour-based ‘oxide printer’ has the potential to be scaled up for commercial production lines.