Synthesis and characterization of a perovskite film for solar cells applications

The synthesis of a perovskite based on lead halide CH₃NH₃PbI₃ is reported. Simple precursors such as PbI and CH₃NH₃I are used to synthesize this material under ambient conditions. The variation in the number of solution droplets on the substrate leads to different perovskites film thicknesses. The morphology, structure, optical gap of these perovskites are investigated using SEM couples with EDS, X-ray diffraction, and UV/Visible measurements, respectively. The spectra showed a blue shift in the absorption edge towards lower wavelength. The phenomenon is attributed to the annealing required to dry the perovskite during the spinning process. The effect of temperature is more efficient in restructuring the material when small number of drops was used as evidenced from the diminishing of the PbI₂ peaks by increasing the number of drops.