A critical perquisite for the commercialization of perovskite photovoltaics lies in the development of high‐efficiency perovskite solar modules (PSMs) with long‐term operational stability. Herein, we report in situ dual‐stage surface reaction engineering, by introducing a multifunctional 3‐amino‐4‐mercapto(trifluoromethyl)benzene hydrochloride (ATB), to enhance operational stability in high‐performance PSMs. Initially, the ATB selectively reacts with surface formamidinium ions, reducing the perovskite defects and inducing an n‐type doping that corresponds to an optimized interfacial energy level match. Subsequently, the thiol groups with redox properties in ATB initialize a reaction cycle between I 2 and Pb 0 generated during the operational aging of perovskite device, thus suppressing the defect accumulation and enhancing the device operational stability. As a consequence, the PSMs achieved PCEs of 23.3% (11.2 cm 2 , aperture area) and 21.2% (694.5 cm 2 , aperture area), with exceptional operational stability retaining > 99% of their initial PCE after 2000 h under continuous 1‐sun illumination at 25°C and > 90% PCE following 1600 h at 85°C.
Liu et al. (Tue,) studied this question.