Biomimetic EUK-134 Synergy Strategy for Dynamic Cyclic Antioxidant Defense and Defect Passivation in Perovskite Solar Cells

Organic-inorganic hybrid perovskites are highly susceptible to oxidative degradation under illumination and oxygen exposure. The primary degradation mechanism involves photogenerated electrons reducing adsorbed oxygen to form highly reactive superoxide radicals (O2•-). These radicals not only initiate lattice iodide loss and organic cation volatilization but also produce hydrogen peroxide (H2O2) as a dismutation byproduct, which further accelerates material decomposition and severely compromises long-term stability. Here, we introduce the biomimetic enzyme mimetic EUK-134 into the perovskite precursor solution, which possesses dual superoxide dismutase (SOD) and catalase (CAT) activities. It effectively scavenges O2•- and decomposes H2O2, blocking the reactive oxygen species (ROS)-mediated degradation pathway. Concurrently, the Cl- ions from EUK-134 modulate perovskite crystallization and fill iodide vacancies, whereas the phenolic oxygen groups passivate undercoordinated Pb2+ sites. This synergistic effect achieves a champion power conversion efficiency of 24.48%. Notably, the unencapsulated device retains 90.39% of its initial efficiency after 2000 h of aging in nitrogen and maintains 75.45% after 1000 h under ambient conditions (25 °C, RH ≈ 40-60%, room light), significantly outperforming the control device. This work provides a reliable and powerful strategy for fabricating highly stable and long-lived photovoltaic devices.