Phase-Transition-Cycle-Induced Recrystallization of FAPbI3 Film in An Open Environment Toward Excellent Photodetectorswith High Reproducibility

Meng Wang,Fengren Cao,LinxingMeng, Min Wang, Liang Li*

Adv. Mater. 2022, 34, 2200221

https://doi.org/10.1002/advs.202204386

Perovskite is an attractive building block for future optoelectronic applications. However, the strict fabrication conditions of perovskite devices impede the transformation of lab techniques into commercial applications. Here, a facile annealing-free posttreatment is proposed to reconstruct the perovskite film to obtain high-performance photodetectors with an optimized production rate. With posttreatment by methylamine thiocyanate, the prefabricated formamidinium-lead triiodide (FAPbI3) film will undergo a recrystallization process consisting of a repeating phase-transition-cycle (PTC) between the black and yellow phases of FAPbI3, which improves the crystal quality and eliminates defects. As a result, some casually prepared or even decomposed perovskite films can be reconstructed, and the dispersion degree of the device performance based on the posttreatment method decreases by ≈21% compared to the traditional antisolvent method. This facile and annealing-free posttreatment will be an attractive method for the future industrial production of perovskite devices.