Operational Performance and Stability of FA_0.85Cs_0.05Rb_0.05MA_0.05Pb(I_0.95Br_0.05)₃ Solar Cells under International Space Station Orbital Conditions

The International Space Station (ISS) is subjected to rapid thermal cycles from ∼+100 to −100 to +100 °C every 90 min. This has adverse mechanical and thermal stress on perovskite solar cells used for applications in the ISS orbit, which is exacerbated by the cyclic and rapid transition from direct illumination with increasing temperature to cold dark regimes. The inherent stressors to which the solar cell is exposed are observed initially to have little effect in the first orbital cycle but lead to increasing performance degradation in subsequent cycles. The decline in short circuit current (J_sc) and fill factor (FF) observed is attributed to thermally induced interfacial degradation in the device architectures studied. Furthermore, these temperature regimes also induce changes in the emission from the perovskite absorber as the temperature increases. Specifically, improved luminescence intensity is observed after thermal cycling, with a reduced contribution from darker lower-energy domains, which is attributed to material decomposition during thin-film deposition and/or the nonoptimum solution homogeneity during synthesis.