ABSTRACT Intrinsic defects and environmental instability remain critical bottlenecks for perovskite solar cells (PSCs). Here, we report the deployment of heme (C 34 H 32 FeN 4 O 4 )—as a dual‐function modifier to concurrently address defect passivation and oxidative stability. The molecular architecture of heme, featuring redox‐active Fe 2+ centers and conjugated porphyrin rings, enables Lewis acid‐base coordination with undercoordinated Pb 2+ /I − at grain boundaries, reducing trap‐state density by 60% and promoting uniform crystal growth. This results in a significant power conversion efficiency (PCE) enhancement from 21.53% to 24.71% via suppressed nonradiative recombination and improved charge extraction. Beyond efficiency improvements, the heme‐modified devices exhibit superior environmental stability enabled by dual protective mechanisms: the hydrophobic porphyrin framework reduces moisture ingress, while the redox‐active Fe 2+ center forms a sacrificial oxygen scavenging layer. Specifically, heme‐mediated oxidation (Fe 2+ →Fe 3+ ) preferentially consumes ambient oxygen, retarding perovskite degradation under aerobic conditions. As a result, the modified devices retain 91.6% of their initial PCE after 3500 h of continuous air exposure without encapsulation, showcasing a 3‐fold improvement in oxygen tolerance compared to pristine devices. This work leverages metalloporphyrin structures to address both efficiency and stability bottlenecks in PSCs, demonstrating that rational molecular design inspired by biological redox systems can propel effective solutions for next‐generation photovoltaic technologies.
Guo et al. (Tue,) studied this question.