Understanding Differences in the Crystallization Kinetics between One‐Step Slot‐Die Coating and Spin Coating of MAPbI ₃ Using Multimodal In Situ Optical Spectroscopy

To develop a detailed understanding about halide perovskite processing from solution, the crystallization processes are investigated during spin coating and slot-die of MAPbI3 at different evaporation rates by simultaneous in situ photoluminescence, light scattering, absorption measurements. Based on time evolution optical parameters it is found that for both methods initially solvent-complex-structures form, followed crystallization. The latter proceeds two stages coating, while only one phase occurs. For methods, with increasing rates, kinetics solvent-complex structure remain constant relative scale, whereas duration second increases. This appears restricted due to differences morphologies which forms. work emphasizes importance exact precursor state properties formation. It further demonstrates analyses multimodal spectroscopy allows gaining fundamental take place solution perovskites, independent specific method.