Chin, Xin YuTurkay, DenizSteele, Julian A.Tabean, SabaEswara, SanthanaMensi, MounirFiala, PeterWolff, Christian M.Paracchino, AdrianaArtuk, KeremJacobs, DanielGuesnay, QuentinSahli, FlorentAndreatta, GaelleBoccard, MathieuJeangros, QuentinBallif, Christophe2023-08-282023-08-282023-08-282023-07-0710.1126/science.adg0091https://infoscience.epfl.ch/handle/20.500.14299/200276WOS:001030999200027Silicon solar cells are approaching their theoretical efficiency limit of 29%. This limitation can be exceeded with advanced device architectures, where two or more solar cells are stacked to improve the harvesting of solar energy. In this work, we devise a tandem device with a perovskite layer conformally coated on a silicon bottom cell featuring micrometric pyramids-the industry standard-to improve its photocurrent. Using an additive in the processing sequence, we regulate the perovskite crystallization process and alleviate recombination losses occurring at the perovskite top surface interfacing the electron-selective contact [buckminsterfullerene (C-60)]. We demonstrate a device with an active area of 1.17 square centimeters, reaching a certified power conversion efficiency of 31.25%.Multidisciplinary SciencesScience & Technology - Other Topicsefficiencysiliconmicrometertext::journal::journal article::research article