When Aggregation‐Induced Emission Meets Perovskites: Efficient Defect‐Passivation and Charge‐Transfer for Ambient Fabrication of Perovskite Solar Cells

Abstract The intrinsic defects in perovskite film can serve as non‐radiative recombination center to limit the performance and stability of metal halide perovskite solar cells (PSCs). The additive engineering in perovskite film is always applied to produce high‐efficiency PSCs in recent years. Here, a typical donor‐acceptor (D−A) structured aggregation‐induced emission (AIE) molecule tetraphenylethene‐2‐dicyano‐methylene‐3‐cyano‐4,5,5‐trimethyl‐2,5‐dihydrofuran (TPE‐TCF) was introduced into perovskite film. The D−A structure of TPE‐TCF molecule provided additional charge transfer channels, contributing to transporting electron of TPE‐TCF‐based device. The cyano (C≡N) of TPE‐TCF can interact with the uncoordinated Pb to from a relatively stable intermediate, PbI 2 ⋅TPE‐TCF, resulting in the slower crystal growth, reduced the defects at the grain boundaries and suppressed carrier recombination. As a consequence, the power conversion efficiency (PCE) of TPE‐TCF‐modified PSCs achieved a remarkably enhanced from 15.63 to 19.66 % with negligible hysteresis, which was prominent in methylammonium lead iodide‐based devices fabricated under ambient condition. Furthermore, the PSCs modified by AIE molecule possessed an outstanding stability and maintain about 86 % of the initial PCE after 300 h storage in air at 25–35 °C with a high relative humidity (RH) of ≈85 %. This work suggests that incorporating AIE molecule into perovskite is a promising strategy for facilitating high‐performance PSCs commercialization in ambient environment without glovebox.