Title: Prussian blue regulates ion dynamics in perovskite solar cells

Authors: Cao, Fang; Ma, Mengen; Zhou, Junjie; Cheng, Fangwen; Dai, Zheng; Chen, Linyuan; Hong, Yuhao; Tian, Di; Zhan, Shaoqi; Chen, Yu; An, Pengfei; Li, Xin; Lin, Xinyu; Su, Zhenhuang; Gao, Xingyu; Yang, Jianhao; Huang, Xiaofeng; Yin, Jun; Li, Jing; Zhang, Hua; Wei, Xian-Kui; Qu, Zhiguo; Liu, Chong; Yi, Chenyi; Mai, Yaohua; Wu, Binghui; Zheng, Nanfeng

Abstract: Perovskite photovoltaics are limited by structural instabilities initiated during crystallization and amplified under operation. We report that a lattice-matched Prussian blue scaffold directs heterogeneous nucleation to produce highly oriented, strain-relaxed films. Its redox-active Fe–C≡N–Fe network mediates the conversion of Pb 0 and I 0 defects, and its rigid open framework suppresses A-site cation redistribution and the resulting electronic inhomogeneity under bias. This strategy yielded champion power conversion efficiencies of 26.1% (n-i-p) and 26.9% (p-i-n; 26.2% certified), scaling to 23.4% in 6-centimeter–by–6-centimeter minimodules and a certified 22.9% in 30-centimeter–by–30-centimeter submodules. Submodules with initial power conversion efficiencies ranging from 20.2 to 21.0% showed robust durability under accelerated aging and no discernible decline relative to a silicon reference over 5 months of outdoor testing.

Full-Link: https://doi.org/10.1126/science.aef5487