Resolving Scaling Issues in Self‐Assembled Monolayer‐Based Perovskite Solar Modules via Additive Engineering

Abstract Molecular self‐assembled monolayers (SAMs), anchored on a transparent conductive oxide, serve as a class of effective hole‐selective contacts in high‐performance lab‐scale perovskite solar cells (PSCs). However, scaling these SAM‐based PSCs to large‐area modules introduces challenges, such as the de‐wetting of the perovskite ink on glass around P1 scribe zones—a part of the module design – which compromises film uniformity and reproducibility. To overcome these coverage anomalies, the study incorporates 1,3‐dimethyl‐3,4,5,6‐tetrahydro‐2(1H)‐pyrimidinone (DMPU) into the SAM solution, enhancing the interaction between the SAM and the perovskite ink and improving wettability. The approach leads to the fabrication of wide‐bandgap (1.67 eV) PSCs with power conversion efficiencies (PCEs) of up to 22.4% for small‐area devices (0.057 cm²) and 20% for perovskite mini‐modules (9.8 cm²) with high reproducibility. Additionally, the target devices demonstrate enhanced photostability, maintaining 80% of their initial PCE after 490 hours of maximum power point tracking under continuous 1‐sun illumination. This study identifies the key challenges in scaling up SAM‐based perovskite modules and presents a promising strategy for fabricating scalable SAM‐based perovskite modules.