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.