Solvent Regulation Strategy for Ambient Preparation of Perovskite Solar Cells
This work shows that the carbonyl oxygen in the solvent N-ethyl-2-pyrrolidone(NEP)has a stronger elec-tronegativity than N-methyl-2-pyrrolidone(NMP)by extended huckel theoretical calculations,and predicts a stronger interaction between NEP and PbI2.The study employs a solvent-regulation-assisted crystallization strategy to effec-tively suppress the formation of solvent-perovskite complex intermediates,improving the crystallization quality of the perovskite films.The highest power conversion efficiency(PCE)of FAPbI3 perovskite solar cells fabricated in atmo-sphere increased from 20.25%to 21.05%,and the average efficiency improved from 18.43%to 19.50%.The sta-bility of unencapsulated devices was maintained at 82.1%of their initial efficiency after 1 200 h under 10%-20%RH at room temperature.Moreover,this strategy is applicable to other perovskite chemical compositions(FA0.95Cs0.05PbI3)for perovskite precursor solutions,demonstrating the universality of which.This research would contribute to the research on the ambient preparation of perovskite solar cells.
perovskite solar cellsambient printed devicescrystallization regulation