A further characterization which has been carried out on the present samples is related to the assessment of their air-stability. It is known that 2D perovskites are, in general, more resistant to ambient conditions with respect to 3D perovskites due to the highly hydrophobic characteristics of the organic spacer. On the other hand, when tin or germanium are present, the easy oxidation of these elements from +2 to +4 may occur also in low-dimensional perovskites. We afforded since some time a through engineering of stable lead free perovskites trying to provide more environment resistant samples. In this respect, we report here the structural and optical results obtained by exposing the samples for one month to laboratory air (RH around 45%). Figures The data clearly demonstrate that iodide-based samples undergo an extended degradation as demonstrated by the XRD patterns showing the appearance of different diffraction patterns (which, at present cannot be assigned to any known phase). Such structural change is also confirmed by the marked variation of the spectroscopic data (Figs. and).