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

Abstract

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‐NH 2 can be successfully assembled on the prototype perovskite surface to provide waterproof ability via a facile functionalization process. More importantly, the assembled POSS‐NH 2 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‐NH 2 in perovskite materials opens up an alternative direction toward improving the humidity tolerance of perovskite solar cells while retaining the device performance.