Two-dimensional perovskite templates for durable, efficient formamidinium perovskite solar cells
Siraj Sidhik, Isaac Metcalf, Wenbin Li, Tim Kodalle, Connor J. Dolan, Mohammad Khalili, Jin Hou, Faiz Mandani, Andrew J. Torma, Hao Zhang, Rabindranath Garai, Jessica Persaud, Amanda B. Marciel, Itzel Alejandra Muro Puente, G. N. Manjunatha Reddy, Adam Balvanz, Muhammad A. Alam, Claudine Katan, Esther H. R. Tsai, David S. Ginger, David P. Fenning, Mercouri G. Kanatzidis, Carolin M. Sutter‐Fella, Jacky Even, Aditya D. Mohite
Abstract
We present a design strategy for fabricating ultrastable phase-pure films of formamidinium lead iodide (FAPbI 3 ) by lattice templating using specific two-dimensional (2D) perovskites with FA as the cage cation. When a pure FAPbI 3 precursor solution is brought in contact with the 2D perovskite, the black phase forms preferentially at 100°C, much lower than the standard FAPbI 3 annealing temperature of 150°C. X-ray diffraction and optical spectroscopy suggest that the resulting FAPbI 3 film compresses slightly to acquire the (011) interplanar distances of the 2D perovskite seed. The 2D-templated bulk FAPbI 3 films exhibited an efficiency of 24.1% in a p-i-n architecture with 0.5–square centimeter active area and an exceptional durability, retaining 97% of their initial efficiency after 1000 hours under 85°C and maximum power point tracking.