Efficient Moisture-Resistant Perovskite Solar Cell With Nanostructure Featuring 3D Amine Motif

Organic–inorganic halide perovskite-based solar cells (PSCs) have attracted intensive attention due to their high power conversion efficiency (PCE) and low fabrication cost. However, the long-term stability is of central importance as it enables the application of hybrid perovskite materials in real-world devices, where addressing the performance degradation issue in humid conditions is urgently needed. Conceptually different from a previous study based on alkyl ammonium cations, here it is demonstrated that a new type of three-dimensional hydrophobic ammonium cation, namely POSS-NH₂ can be successfully assembled on the prototype perovskite surface to provide waterproof ability via a facile functionalization process. More importantly, the assembled POSS-NH₂ on the surface is able to tune the optoelectronic behavior of the perovskite film and the relevant interfaces, which could ultimately benefit the device performance with PCEs over 20%, slightly higher than the photovoltaic behavior derived from pristine perovskites. The employment of POSS-NH₂ in perovskite materials opens up an alternative direction toward improving the humidity tolerance of perovskite solar cells while retaining the device performance.