Chemical passivation and grain-boundary manipulation via in situ cross-linking strategy for scalable flexible perovskite solar cells
Weifu Zhang, Jian Liu, Wei Song, Jiahong Shan, Haowei Guan, Jun Zhou, Yuanyuan Meng, Xinyu Tong, Jintao Zhu, Mengjin Yang, Ziyi Ge
Abstract
Flexible perovskite solar cells (f-PSCs) are considered the most promising candidates in portable power applications. However, high sensitivity of crystallization on the substrate and the intrinsic brittleness usually trade off the performance of f-PSCs. Herein, we introduced an initiator-free cross-linkable monomer (2,5-dioxopyrrolidin-1-yl) 5-(dithiolan-3-yl)pentanoate (FTA), which can chemically passivate defects and enable real-time fine regulation of crystallization. The resulting perovskite film exhibited higher crystallinity, enlarged grain size, and reduced dependence on the substrate. In addition, the cross-linked FTA [CL(FTA)] distributed along the grain boundaries effectively released the residual stress and securely bound the grains together. Consequently, the CL(FTA)-modified flexible PSCs achieved a record-breaking efficiency of 24.64% (certified 24.08%). Moreover, the scalable potential has been verified by the corresponding rigid and flexible modules, delivering impressive efficiencies of 19.53 and 17.13%, respectively. Furthermore, the optimized device demonstrated bending durability and improved operational stability, thereby advancing the progress of f-PSCs toward industrialization.