Cation optimization for burn-in loss-free perovskite solar devices

Hybrid 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.