The FA1-XMAXPbI3 System: Correlations among Stoichiometry Control, Crystal Structure, Optical Properties, and Phase Stability

The FA(1-x)MA(x)PbI(3) solid solution has been carefully investigated in terms of the MA/FA stoichiometry, crystal structure, and optical properties. This work allowed for the determination of reliable correlations between the amount of protonated amine and the physicochemical properties. The deleterious effect of aging on the mixed MA/FA. composition was observed by diffraction and optical measurements, showing progressive phase separation within the samples.