Rapid Deposition of PbI₂ Precursors in Vacuum/Solution Hybrid Process for Efficient and Industrially Feasible Perovskite Solar Cells

Commercializing single‐junction and tandem perovskite solar cells (PSCs) requires scalable, reproducible, and rapid deposition techniques. While spin coating is a commonly used method for fabricating lab‐scale high‐efficiency PSCs, large‐area and uniform deposition with low material waste remains a challenge. This study explores a hybrid deposition method in which an inorganic PbI 2 precursor is deposited by vacuum evaporation followed by a solution process of organic halides. In particular, the impact of varying the PbI 2 deposition rate ( R d ) over a wide range (0.03–2.84 nm s −1 ) on material properties and the photovoltaic performance is investigated and compared with those by the conventional two‐step spin‐coating method. It appears that the R d significantly influences surface morphology of the PbI 2 precursor films and the grain size/composition of the perovskite films. The optimal R d of ∼0.7–0.8 nm s −1 (∼6−7 min deposition) results in a large‐grain‐size perovskite and a power conversion efficiency (PCE) of over 20%, which exceeds that of the spin‐coated reference PSC (19.1%). Notably, an increase of R d up to ∼2–3 nm s −1 (∼2 min deposition time) still maintains a comparable PCE of 18.8%. These results demonstrate the robustness of device performance against rapid inorganic precursor deposition, underscoring the potential of the hybrid deposition method for industrial‐scale production.