Sodium Dodecylbenzene Sulfonate Interface Modification of Methylammonium Lead Iodide for Surface Passivation of Perovskite Solar Cells

Perovskite solar cells (PSCs) have been developed as a promising photovoltaic technology because of their excellent photovoltaic performance. However, interfacial recombination and charge carrier transport losses at the surface greatly limit the performance and stability of PSCs. In this work, the fabrication of high-quality PSCs based on methylammonium lead iodide with excellent ambient stability is reported. An anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), is introduced to simultaneously passivate the defect states and stabilize the cubic phase of the perovskite film. The SDBS located at grain boundaries and the surface of the active layer can effectively passivate under-coordinated lead ions and protect the perovskite components from water-induced degradation. As a result, a champion power conversion efficiency (PCE) of 19.42% is achieved with an open-circuit voltage (VOC) of 1.12 V, a short-circuit current (JSC) of 23.23 mA cm-2, and a fill factor (FF) of 74% in combination with superior moisture stability. The SDBS-passivated devices retain 80% of their initial average PCE after 2112 h of storage under ambient conditions.