Bilateral Interface Engineering for Efficient and Stable Perovskite Solar Cells using Phenylethylammonium Iodide

摘要： Achieving high efficiency and long-term device stability is a vital issue for the commercialization of organic-inorganic hybrid perovskite solar cells (PeSCs). In this work, phenyl ethyl-ammonium iodide (PEAI)-induced bilateral interface engineering was developed to improve the device efficiency and stability of methylammonium lead triiodide (MAPbI3)-based PeSCs. Introducing PEAI onto poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) layer modifies the surface properties of the PEDOT:PSS and facilitates the formation of a high-quality perovskite active layer with enlarged grains on the PEDOT:PSS. The PEA+ in the PEAI-PEDOT:PSS also alters the work function of the PEDOT:PSS, leading to a reduction in the energy difference between the PEDOT:PSS and MAPbI3 perovskite layer, which decreases energy loss during charge transfer. Additionally, depositing PEAI onto three dimensional (3D) perovskite yields a two dimensional/three dimensional (2D/3D) stacked structure for the perovskite active layer. Because the two dimensional (2D) top layer acts as a capping layer to prevent water penetration, the stability of the perovskite active layer is significantly enhanced. A PeSC device fabricated based on this combination exhibits enhanced power conversion efficiency and extended device lifetime compared to a pristine PeSC. Under high-humidity conditions (75 ± 5%), the PEAI-treated PeSC retains 88% of its initial power conversion efficiency (PCE) after 100 h. In contrast, a pristine PeSC device loses over 99% of its initial PCE after only 25 h under the same conditions.