Air‐Stable, Efficient Mixed‐Cation Perovskite Solar Cells with Cu Electrode by Scalable Fabrication of Active Layer

High efficiency and air stable doctor-blade coated perovskite solar cells are reported. The high quality mixed cation perovskite film (FA x MA1− x PbI3) is fabricated by taking the unique advantage of doctor-blade coating method, based on which solar cell efficiency larger than 18% is realized. In addition, choosing copper as cathode enhances device environmental stability substantially, paving the way for real applications. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.