Study of Structural, Optical and Electrical Properties of MA(FA)SnICl2 Perovskite Thin Films Synthesized by One-Step Spin Coating

In this research, MASnICl2 and FASnICl2 thin layers were synthesized by the one-step spin coating method, and then their structural, optical and electrical properties were investigated. The study of these samples (structural properties) showed that the layers have a tetragonal structure (α- phase perovskite), and with the change of organic cation, the crystallinity and morphology of the layers significantly change. These changes also have influences in the optical and electrical properties of the samples. The perovskite layers have a high absorption coefficient (of the order of 105 cm-1) in the visible range. The bandgap for the FASnICl2 layer was 1.48 eV and for the MASnICl2 layer was 1.54 eV. A strong peak close to bandgap was observed in the room temperature PL of the layers, which was remarkably more intense for the FASnICl2 sample. This study showed that the FASnICl2 layers have better crystallinity, lower electrical resistance, higher optical sensitivity and acceptable optical response comparing the MASnICl2 layers, and therefore, they can be suitable options for use as an adsorbent layer in perovskite solar cells.