Low‐Cost, Scalable Fabrication of Multi‐Dimensional Perovskite Solar Cells and Modules Assisted by Mechanical Scribing

Abstract The performance and scalability of perovskite solar cells (PSCs) based on 3D formamidinium lead triiodide (FAPbI 3 ) absorber are often hindered by defects at the surface and grain boundaries of the perovskite. To address this, the study demonstrates the use of pyrrolidinium iodide for the in situ formation of an energetically aligned 1D pyrrolidinium lead triiodide (PyPbI 3 ) capping layer over the 3D FAbI 3 perovskite. The thermodynamically stable PyPbI 3 perovskitoids, formed through cation exchange reactions, effectively reduce surface and grain boundary defects in the FAPbI 3 perovskite. In addition to improved phase stability, the resulting 1D/3D perovskite film forms a cascade energy band alignment with the other functional layers in PSCs, enabling a barrier‐free interfacial charge transport. With a maximum power conversion efficiency (PCE) of ≈23.1% and ≈20.7% at active areas of 0.09 and 1.05 cm 2 , respectively, the 1D/3D PSCs demonstrate excellent performance and scalability. Leveraging this improved scalability, the study has successfully developed a mechanically‐scribed 1D/3D perovskite mini‐module with an unprecedentedly high PCE of ≈20.6% and a total power output of ≈270 mW at an active area of ≈13.0 cm 2 . The 1D/3D multi‐dimensional perovskite film developed herein holds great promise for producing low‐cost, high‐performance perovskite photovoltaics at both the cell and module levels.