Author(s): Lu, JY (Lu, Jiangying); Wu, YL (Wu, Yulin); Wu, S (Wu, Shan); Zhao, J (Zhao, Jing); Wang, JY (Wang, Jinyao); Lin, RK (Lin, Runkang); Zou, HY (Zou, Huayi); Lu, SD (Lu, Shudi); Liu, K (Liu, Kong); Yue, SZ (Yue, Shizhong); Wang, ZJ (Wang, Zhijie); Zhou, LY (Zhou, Liya); Qu, SC (Qu, Shengchun)

Source: JOURNAL OF MATERIALS CHEMISTRY A 

DOI: 10.1039/d4ta02248c  Early Access Date: JUN 2024  Published Date: 2024 JUN 10  

Abstract: The two-step method presents an efficient means to streamline the fabrication process of high-quality and reproducible perovskite films, making it a more suitable option for the fabrication of large-scale commercial perovskite solar cells. However, a challenge with the two-step method lies in the incomplete conversion of PbI2, leading to decreased device performance. To address this issue, potassium l-glutamate (PL-Glu) is introduced to modify the crystal orientation of PbI2, yielding a perovskite buried interface devoid of any PbI2 residue. This modification enables better infiltration of FAI, resulting in perovskite films with enhanced crystal quality, thereby significantly reducing the adverse impact of non-radiative recombination caused by the incomplete conversion of PbI2. Moreover, this method optimizes the energy level structure of the SnO2 electron transport layer, improving charge transport efficiency at the perovskite/SnO2 interface. Consequently, n-i-p perovskite solar cells achieve a power conversion efficiency (PCE) of 24.1% with a high fill factor of 82.9%. The PL-Glu-modified device maintained 92% of the initial PCE after 2700 hours under nitrogen. This study provides a novel engineering strategy for simultaneously optimizing perovskite absorbers and interfaces.