In Situ Construction of Multi‐Functional Polymer Network Toward Durable Perovskite Solar Cells

Abstract Enhancing the crystalline quality of perovskite thin films and stabilizing their internal grain boundaries are essential in guaranteeing the extended longevity of perovskite solar cells. Herein, an in situ polymerization strategy is presented to produce weak chemical bond networks in perovskite films. The introduction of acrylamide monomer into the perovskite precursor solution facilitates the rearrangement of [PbI ₆ ] ⁴⁻ octahedra, resulting in a significant enhancement of the crystal quality of the perovskite films. With the presence of C═C bonds, the in situ polymerization of acrylamide at grain boundaries can form polymer networks, which can efficiently passivate the detrimental defects associated with grain boundaries. The perovskite solar cells with an impressive power conversion efficiency (PCE) of 26.05% (certified at 25.06%) are achieved, combined with highly improved operational stability with T ₉₈ = 2034 h. As expected, large‐area module based on this strategy achieved an impressive PCE of 23.02% with an active area of 14 cm ² .