Surface Passivation for Halide Optoelectronics: Comparing Optimization and Reactivity of Amino-Silanes with Formamidinium

) cations in solution and in the solid state. This work underscores the importance of optimizing deposition conditions to balance effective passivation with potential performance loss and elucidates previously unrecognized reactive chemistry between amino-silane passivating agents and halide perovskites.