Precursor\nInk Engineering to Implement Vacuum Extraction\nMethod for Scalable Production of Perovskite Solar Cells

Engineering perovskite precursor ink to widen the processing\nwindow\nis crucial to obtaining uniform, compact, and pinhole-free perovskite\nfilms at scale using industrially relevant solution coating techniques.\nHere, we introduce a ternary solvent system and systematically investigate\nthe impacts of coordinating solvents, <i>N</i>-methyl-2-pyrrolidone\n(NMP) and <i>N</i>,<i>N</i>′-dimethylpropyleneurea\n(DMPU), on the physical properties of the slot-die-coated perovskite\nfilms and on the corresponding device performance. Tailoring NMP and\nDMPU concentrations in the precursor ink allows us to control the\nperovskite intermediate phase formation and widen the processing window,\nenabling the reproducible production of perovskite films with high\nphotoelectrical quality at scale. Using the optimized precursor ink,\nwe demonstrate slot-die-coated perovskite minimodules with power conversion\nefficiencies of 19 and 16% on 56 and 100 cm<sup>2</sup> substrates,\nrespectively.