Enhancing a Perovskite Solar Cell and Module by Suppressing Protonation through Chelating Agents

Formamidinium-based perovskites (FA perovskites) often incorporate methylammonium chloride (MACl) to stabilize the α-FAPbI₃ phase and prevent formation of the δ phase. However, MACl undergoes deprotonation and reacts with FA, leading to the generation of unstable byproducts that can cause component degradation and negatively impact the device performance. In this study, we introduce ethylenediaminetetramethylenephosphonic acid as a corrosion inhibitor, which effectively prevents the formation of these byproducts and stabilizes α-FAPbI₃. The resulting perovskite solar module achieved a power conversion efficiency of 22.44%. Furthermore, the device maintained approximately 83% of its initial efficiency after 2136 h of damp-heat testing (85 °C and 85% RH), while maximum power point tracking retained 88.7% of the initial efficiency after 1000 h.