Crystallization Tailoring for Efficient and Stable Perovskite Solar Cells Via Introduction of Propionic Acid in a Green Anti-Solvent

The new generation of solar cells led by perovskite solar cells (PvSCs) is the best candidate for worldwide energy demands. In the fabrication process of PvSCs, to guarantee reasonable efficiency, toxic solvents are usually employed to assist the crystallization of the perovskite layer. Here, to reduce the risk of fabrication of PvSCs, ethyl acetate (ETAC) as a green antisolvent was used to assist in the formation of the perovskite layer. The current study continued by introducing propionic acid (PA) additive into the ETAC antisolvent to control and improve the perovskite crystallization process. The results reveal that the PA additive enlarges the perovskite domains, leading to reduced charge traps on the surface and boundaries. In addition, the PA suppresses surplus lead iodide in the perovskite layer and guarantees the production of more photo-generated electron-hole pairs in the perovskite layer. Altogether, antisolvent tailoring brings a maximum efficiency of 18.03% for the modified PvSCs group, higher than the 14.54% for the control PvSCs. In addition, the PA-based modified PvSCs compared to the control PvSCs exhibited a higher stability response due to the passivated domain boundaries with a boosted hydrophobicity property.