Enhancing Efficiency of Large-Area Wide-Bandgap Perovskite Solar Modules with Spontaneously Formed Self-Assembled...

Wide-bandgap (WBG) perovskites play a crucial role in perovskite-based tandem cells. Despite recent advances using self-assembled monolayers (SAMs) to facilitate efficiency breakthroughs, achieving precise control over the deposition of such ultrathin layers remains a significant challenge for large-scale fabrication of WBG perovskite and, consequently, for the tandem modules. To address these challenges, we propose a facile method that integrates MeO-2PACz and Me-4PACz in optimal proportions (Mixed SAMs) into the perovskite precursor solution, enabling the simultaneous codeposition of WBG perovskite and SAMs. This technique promotes the spontaneous formation of charge-selective contacts while reducing defect densities by coordinating phosphonic acid groups with the unbonded Pb²⁺ ions at the bottom interface. The resulting WBG perovskite solar cells (PSCs) demonstrated a power conversion efficiency of 19.31% for small-area devices (0.0585 cm²) and 17.63% for large-area modules (19.34 cm²), highlighting the potential of this codeposition strategy for fabricating high-performance, large-area WBG PSCs with enhanced reproducibility. These findings offer valuable insights for advancing WBG PSCs and the scalable fabrication of modules.