Combined Effects of Irradiation and Environmental Stressors on Elemental Migration and Device Stability in Perovskite Solar Cells

The deployment of perovskite solar cells (PSCs) in outer space missions requires an understanding of how they respond to multiple stressors, such as environmental aging during ground testing, degradation from storage or transport between device fabrication and irradiation facilities, the isolated impact of ion irradiation, and the combined impact of all these stressors simultaneously. In this work, we utilized Rutherford backscattering spectrometry (RBS) to study and quantify the elemental migration in operational PSCs (glass/ITO/NiO_<i>x</i>/MeO-2PACz/Cs_0.2FA_0.8PbI₃/C₆₀/BCP/Ag) exposed to He⁺ irradiation, environmental aging, and their combination. The nondestructive nature of RBS ensured that the devices remained functional, making it possible to correlate their performance characteristics before and after the irradiation. Migration of Ag, Pb, I, and In was observed even in pristine devices, with significantly increased migration following irradiation and further enhancement under ambient environment. Devices stored in a glovebox/drybox postirradiation also exhibited similar trends. Postirradiation microscope images showed electrode swelling of varying severity, indicating possible trapped He blister formation in the surface regions. This study further investigates the damaging effects of nuclear energy loss (<i>S</i>_<i>n</i>) and healing effects of electronic energy loss (<i>S</i>_<i>e</i>) from the probing 2 MeV He⁺ beam used during RBS. It also examines the influence of irradiation timing and staging on the performance of devices previously degraded in both ambient and controlled storage conditions.