Supporting Information Boundary Layer Effect on Solvent Evaporation during Perovskite Film Drying by Multi-flow Air Knife

Lead iodide (PbI2, 99.99%), N,N-dimethylformamide (DMF, 99.8%), iodine methylamine (CH3NH3I) were purchased from Xi'an Polymer Light Technology Corp., and used as received. Titanium dioxide precursor solvent was synthesized following the reported procedure.1 Spiro-MeOTAD solution was prepared according to the report.2 It was prepared by dissolving 72.3 mg of spiro-MeOTAD in 1 ml of chlorobenzene, to which 28.8 μl of 4-tertbutylpyridine and 17.5 μl of lithiumbis(trifluoromethanesulfonyl)imide(Li-TFSI) solution (520 mg LI-TSFI in 1 ml acetonitrile, Sigma-Aldrich, 99.8%) were added.