Verification and Mitigation of Proton‐Induced Non‐Ionizing Damage in Perovskite Solar Cells for Space Applications

Perovskite solar cells (PSCs) offer a compelling route to developing lightweight, high‐specific‐power photovoltaic systems suitable for space applications. However, their durability in proton‐rich environments, typical of low‐Earth orbit, remains the key uncertainty that limits their deployment. In this study, we established how proton energy and fluence jointly determine the degradation thresholds in PSCs and showed that non‐ionizing energy loss dominates non‐recoverable degradation. By integrating controlled proton exposures with ion‐transport simulations, we identified energy‐dependent regimes in which atomic displacements drive A‐/X‐site depletion and lattice disorder, resulting in performance collapse beyond the critical accumulated dose. Under proton irradiation, a distinct mechanistic fingerprint was observed: the surface metallic Pb 0 diminished with increasing dose, in contrast to the accumulation of Pb 0 observed under photon irradiation. This finding supports a displacement‐dominated pathway. Finally, we demonstrated parylene‐C encapsulation that mitigates damage, and we defined a practical shielding criterion: effective protection requires a polymer thickness that exceeds the proton penetration depth corresponding to the energy spectrum of a given mission. These results provide both a unified framework for understanding proton–matter interactions in PSCs and for formulating actionable design rules for radiation‐hardened, lightweight solar modules capable of extended operation in space.