Enhancing Orbit–Orbit Interaction and Regulating Defect Passivation in Vacuum-Assisted Flexible Perovskite Films

Developing a reliable postprocessing strategy is crucial for promoting the development of F-PSCs as a result of structure-dependent optoelectronic characteristics. Here, a crystallization scheme is devised for the deposition of high-quality perovskite films through a vacuum post-treatment strategy. This method adopts a vacuum process to prepare the freshly coated precursor film and subsequent thermal annealing to achieve controllable crystallization kinetics. Meanwhile, we show smaller compressive strain in a perovskite MAPbI 3 film-coated PEN substrate with vacuum treatment. The lattice strain in the flexible perovskite thin film leads to orbit–orbit interaction enhancement according to the linear/circular photoexcitation-modulated photocurrent ( J SC ). Furthermore, we reveal that the decrease in trap states in the MAPbI 3 perovskite is due to the increase in compressive lattice strain. This work provides a feasible method for further improving the optoelectronic performance of F-PSCs.