Low-cost green antisolvent with an ultrawide processing window for efficient and stable perovskite solar cells

Antisolvent engineering is one of the most useful strategies to get high-efficiency perovskite solar cells (PSCs). Nevertheless, the most present commonly used effective antisolvents, such as chlorobenzene and diethyl ether, are toxic and expensive. Moreover, these antisolvents applied in PSCs are rather restricted due to their narrow processing window. Herein, we report a low-cost green antisolvent isopropanol (IPA) that displays ultrawide processing window, which dramatically enhances the reproducibility of PSCs. The highest power conversation efficiency of PSCs treated by IPA can reach as high as 24.8%. The origin of IPA effects is further disclosed by the intermolecular hydrogen-bonding force between IPA and DMF/DMSO, and the force can effectively remove DMF/DMSO in the spinning perovskite precursor film and helpfully enhance perovskite crystal growth with less carrier recombination as demonstrated by using various techniques. Our results here demonstrate a cheap green antisolvent for reproducible, high-efficient, stable PSCs and also provide an in-depth understanding the significant role of antisolvent in the fabrication of PSCs.