Lead halide perovskite crystallization in-situ during spin- coating.

Hybrid perovskite structures are promising materials for inexpensive and efficient solar cells. In particular formamidinium lead triiodide (FAPbI3) perovskite has shown to be a promising material for single-junction solar cells, reaching a certified power conversion efficiency of over 25%. However, FAPbI3 solar cells face one hurdle on the way to commercialization. The desired black alpha-phase FAPbI3 can spontaneously transform into a photoinactive delta-phase at room temperature. Therefore, the realization of stable and pure phase alpha-FAPbI3 perovskites is of utmost importance. The production method has a huge impact on the crystallization pathway and the quality of the final film. Here we propose a comparative real time study of the three most promising methods: annealing, gas quenching and anti-solvent method. This will give us insight into the different crystallization pathways and how they impact the quality of the resulting film.