Highly-Efficient and Long-Term Stable Perovskite Solar Cells Enabled by a Cross-Linkable n-Doped Hybrid Cathode Interfacial Layer

Hybrid organic–inorganic halide perovskite solar cells (PeSCs) are currently at the forefront of emerging photovoltaic technologies due to their potential for providing cost-effective highly efficient solar energy conversion. The interfacial layers play an important role in determining the efficiency and stability of PeSCs. In this work, a solution-processed cross-linkable hybrid composite film composed of N,N-dimethyl-N-octadecyl(3-aminopropyl)trimethoxysilyl chloride silane (DMOAP)-doped [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) is demonstrated as an effective cathode interfacial layer for PeSCs. The hydrolyzable alkoxysilane groups on DMOAP enable moisture cross-linking through the formation of stable siloxane bonds, which is effective in ensuring uniform film coverage of PC61BM on the perovskite layer and preventing the undesirable reaction between the mobile halide ions and Ag electrode. On the other hand, the quaternary ammonium cations on DMOAP can induce the formation of favorable interf...