Experimental Validation of Strong Proton Radiation Tolerance of Surface-Treated All-Inorganic CsPbI 3 Perovskite Solar Cells for Space Applications

The rapid expansion of space-based initiatives and the increasing deployment of satellites have intensified the demand for high-performance, radiation-tolerant photovoltaics (PV). This study investigates the radiation tolerance of all-inorganic CsPbI3 perovskites for space PV applications. Combining simulations and experimental evaluations, we compare the properties of CsPbI3 films depending on the surface treatments using long chain cations. Octylammonium iodide (OAI) treatment forms a quasi-2D perovskite structure, whereas phenethylammonium iodide (PEAI) induces a molecular cation layer. Under harsh proton irradiation (2 × 1014 protons/cm2 at 0.05 MeV), OAI-treated devices exhibited only a 19% efficiency reduction, significantly lower than the performance degradation observed in organic–inorganic hybrid perovskite PVs. Moreover, OAI treatment does not have adverse effects after irradiation, while the PEAI layer results in a severe deviation in surface electrical potential following irradiation. These findings suggest new directions for using all-inorganic PSCs in high-radiation environments, prompting further investigation into next-generation space PV technologies.