Probing self-healing dynamics in perovskite solar cells under proton irradiation via in situ and in operando characterization

Perovskite solar cells (PSCs) combine high efficiency with remarkable defect tolerance, making them attractive for radiation-hard energy systems. While previous studies have explored their radiation stability, the mechanisms governing in situ recovery under particle irradiation remain unclear. Here, we examine PSCs under in situ proton irradiation at 60 and 350 keV in high vacuum to isolate intrinsic self-healing from environmental effects. Low-energy irradiation dominated by atomic displacement damage caused cumulative degradation, whereas high-energy irradiation generated fewer permanent defects and promoted localized recovery through ionization and thermal dissipation within the perovskite lattice. Applying a secondary high-energy dose after low-energy damage further enhanced defect annealing, confirming ionization-assisted healing. Real-time current-voltage monitoring captured transient beam-induced photovoltage and rapid post-irradiation recovery. These results reveal a dynamic balance between damage and self-repair, providing more insight into the radiation resilience of perovskite optoelectronics in extreme environments.