Ternary self-assembled molecular contact for ambient-processed perovskite/silicon tandem solar cells
摘要
Self-assembled monolayers (SAMs) represent an effective strategy for the development of perovskite solar cells (PSCs). High-performance PSCs are typically fabricated in an inert atmosphere because ambient moisture disrupts phosphonic-acid SAMs on transparent conductive oxides, leading to surface inhomogeneity and direct exposure of the transparent conductive oxide. However, this dependence on glovebox fabrication constrains scalability and cost-effective manufacturing. Here we present a ternary self-assembled molecular contact comprising glycerol dimethacrylate and 1-acetylguanidine that serves as a process-tolerant hole-selective contact. Glycerol dimethacrylate acts as a cosolvent during SAM deposition to improve film uniformity and is subsequently transformed into a hydrophilic binary network upon mild thermal curing, firmly anchoring the SAM to the substrate, whereas 1-acetylguanidine is incorporated to further suppress interfacial defects. Wide-bandgap PSCs fabricated in ambient conditions achieve a power conversion efficiency of 21.20% (1.00 cm2), with an open-circuit voltage of 1.28 V. When implemented in monolithic perovskite/silicon tandems, cells achieve a power conversion efficiency of 31.72% (certified 31.36%) and 32.60% for fabrication in ambient and inert conditions, respectively. These findings demonstrate that our tailored hole-selective contact provides a robust and process-tolerant interfacial engineering approach for high-efficiency perovskite and tandem photovoltaics manufactured under ambient conditions.