Nanoscale soft interaction-engineered perovskite heterojunctions for highly efficient and reproducible solar cells
Bo Li, Danpeng Gao, Francesco Vanin, Chunlei Zhang, Zexin Yu, Ning Wang, Jie Gong, Shuai Li, Jianqiu Gong, Liangchen Qian, Yen‐Hung Lin, Martin Stolterfoht, Nicholas J. Long, Zonglong Zhu
Abstract
The rational design of perovskite heterojunctions is crucial for advancing the efficiency and operational stability of perovskite solar cells (PSCs). However, conventional methods face challenges in precisely controlling interfacial phase purity at the nanoscale and achieving conformal heterojunction coverage. Herein, we report a ‘soft-soft’ interaction-guided strategy to tailor perovskite heterojunction formation by introducing dimethyl sulfide (DMS) as a soft Lewis base additive in the organic cation solution. The resulting DMS-modulated PSCs achieve a remarkable power conversion efficiency (PCE) of up to 26.70%, with a certified PCE of 26.48%. The devices exhibit exceptional operational stability, retaining over 94% of their initial PCE after 2000 h of maximum power point tracking under continuous 1-sun illumination (ISOS-L-1 protocol). Furthermore, the universality of this ‘soft-soft’ interaction strategy is validated across a range of diverse perovskite compositions and ligand systems, demonstrating its potential for scalable and reproducible PSC fabrication. Conventional design of perovskite heterojunctions face challenges in precisely controlling interfacial phase purity at nanoscale. Here, the authors introduce dimethyl sulfide as a soft Lewis base additive in organic cation solution, achieving certified efficiency of 26.48% in stable solar cells.