Tailoring Phase Alignment and Interfaces via Polyelectrolyte Anchoring Enables Large‐Area 2D Perovskite Solar Cells
Chenxu Han, Yao Wang, Jiabei Yuan, Jianguo Sun, Xuliang Zhang, Claudio Cazorla, Xianxin Wu, Ziang Wu, Junwei Shi, Junjun Guo, Hehe Huang, Long Hu, Xinfeng Liu, Han Young Woo, Jianyu Yuan, Wanli Ma
Abstract
Abstract Ruddlesden–Popper phase 2D perovskite solar cells (PSCs) exhibit improved lifetime while still facing challenges such as phase alignment and up‐scaling to module‐level devices. Herein, polyelectrolytes are explored to tackle this issue. The contact between perovskite and hole‐transport layer (HTL) is important for decreasing interfacial non‐radiative recombination and scalable fabrication of uniform 2D perovskite films. Through exploring compatible butylamine cations, we first demonstrate poly(3‐(4‐carboxybutyl)thiophene‐2,5‐diyl)‐butylamine (P3CT‐BA) as an efficient HTL for 2D PSCs due to its great hydrophilicity, relatively high hole mobility and uniform surface. More importantly, the tailored P3CT‐BA has an anchoring effect and acts as the buried passivator for 2D perovskites. Consequently, a best efficiency approaching 18 % was achieved and we further first report large‐area (2×3 cm 2 , 5×5 cm 2 ) 2D perovskite minimodules with an impressive efficiency of 14.81 % and 11.13 %, respectively.