In-Situ Investigation of Perovskite Solar Cells Under Coupled Vacuum-Thermal Cycling in Extreme Space Environments

Perovskite solar cells (PSCs), due to low-cost and lightweight nature, hold promise for aerospace use. Understanding the behavior of various components of perovskite solar cells under the harsh space conditions remains a critical priority. To date, conventional investigation methods do not allow for complete exclusion of moisture and oxygen from the environment and cannot adequately simulate conditions, which are close to the space environment. In this study, we present an in-situ characterization system that enables investigation of samples under extreme vacuum conditions (10-8 Pa) and a wide temperature range, with elimination of atmospheric influence. Under ultrahigh vacuum and repeated thermal cycling(150 K-430 K), the perovskite absorber undergoes irreversible decomposition, producing degradation products such as metallic lead, lead iodide, and volatile organic compounds. Elevated temperatures induce phase transitions within the material, while thermally driven ion migration across interfaces intensifies non-radiative recombination processes. These structural and compositional changes result in a notable decline in device performance, with the power conversion efficiency decreasing from 24.39% to 20.15% after five thermal cycles, primarily due to reduced short-circuit current. The observed degradation is attributed to material decomposition, thermal instability, and interfacial diffusion, highlighting key challenges for PSC stability in space environments.