Improving the potential of ethyl acetate green anti-solvent to fabricate efficient and stable perovskite solar cells

Until now, in all state-of-the-art efficient perovskite solar cells (PSCs), during the fabrication process of the perovskite layer, highly toxic anti-solvents such as toluene, chlorobenzene, and diethyl ether have been used. This is highly concerning and urgently needs to be considered by laboratories and institutes to protect the health of researchers and employees working towards safe PSC fabrication. Green anti-solvents are usually used along with low-performance PSCs. The current study solves the ineptitude of the typical ethyl acetate green anti-solvent by adding a potassium thiocyanate (KSCN) material to it. The KSCN additive causes delay in the perovskite growing process. It guarantees the formation of larger perovskite domains during fabrication. The enlarged perovskite domains reduce the bulk and surface trap density in the perovskite. It enables lower trap-facilitated charge recombination along with efficient charge extraction in PSCs. Overall, the developed method results in a champion performance of 17.12% for PSCs, higher than the 13.78% recorded for control PSCs. The enlarged perovskite domains warrant lower humidity interaction paths with the perovskite composition, indicating higher stability in PSCs.