Functional group engineering of molecular modifiers for radiation-stable hybrid perovskites

Abstract

Hybrid organic-inorganic perovskites are promising for space photovoltaic applications due to their exceptional optoelectronic properties and high power-to-weight ratio, but orbital deployment is limited by radiation degradation. The influence of modifier structure on radiation resistance remains poorly understood. Here, we systematically investigate the effect of 54 organic additives with diverse functional groups on the radiation stability of mixed-cation Cs_0.1MA_0.15FA_0.75PbI₃ perovskite films under high-flux 8.2 MeV electron irradiation at fluences equivalent to 10 years in low-Earth orbit. Using X-ray photoelectron spectroscopy (XPS) combined with correlation analysis, we identify exploratory associations between molecular features and irradiation-induced changes in the perovskite films. The observed trends indicate that amine-containing groups, particularly –NH₃⁺ moieties attached to aromatic fragments, may be associated with reduced formation of metallic Pb⁰. In contrast, –OH groups may promote Pb–I framework destabilization and correlate with Pb⁰ formation, indicating radiation-induced degradation. Molecular geometry also may matters – additives with oppositely oriented ammonium substituents stabilize more uniformly than those with same-direction substituents. Thus, modifiers containing aromatic –NH₃⁺ groups, a favorable spatial arrangement of ammonium groups, and minimal or no –OH functionalities may represent the promising for radiation-resistant perovskite materials. These findings identify molecular features that may be relevant to the radiation response of modified perovskite films and provide hypotheses for further targeted investigation.