Paek, SanghyunKhan, Sher BahadarFranckevicius, MariusGegevicius, RokasSyzgantseva, Olga A.Syzgantseva, Maria A.Kinche, SachinAsiri, Abdullah M.Roldan-Carmona, CristinaNazeeruddin, Mohammed Khaja2021-06-082021-06-082021-06-082021-03-0710.1039/d1ta00472ghttps://infoscience.epfl.ch/handle/20.500.14299/178731WOS:000627067700008Hybrid lead halide perovskites will potentially lead the future energy scenario if highly efficient cells have long-term stability. Here we combine state-of-the art mixed-cation formulations containing formamidinium (FA) and methylammonium (MA), with optimal guanidinium (Gua)/Cs ratios, enabling the realization of cells providing stability at their maximum efficiency.text::journal::journal article::research article