Blade‐Coating (100)‐Oriented α‐FAPbI 3 Perovskite Films via Crystal Surface Energy Regulation for Efficient and Stable Inverted Perovskite Photovoltaics

作者：Wenhuai Feng, Xudong Liu, Gengling Liu, Guo Yang, Yuxuan Fang, Jinliang Shen, Bowen Jin, Xi Chen, Yuhua Huang, Xu‐Dong Wang, Congcong Wu, Shaopeng Yang, Wu‐Qiang Wu · 发表于：Angewandte Chemie · 年份：2024 · DOI：10.1002/ange.202403196 · 被引用次数：16 · 研究领域：Perovskite Materials and Applications、Quantum Dots Synthesis And Properties、Chalcogenide Semiconductor Thin Films

Abstract Photoactive black‐phase formamidinium lead triiodide (α‐FAPbI 3 ) perovskite has dominated the prevailing high‐performance perovskite solar cells (PSCs), normally for those spin‐coated, conventional n‐i‐p structured devices. Unfortunately, α‐FAPbI 3 has not been made full use of its advantages in inverted p‐i‐n structured PSCs fabricated via blade‐coating techniques owing to uncontrollable crystallization kinetics and complicated phase evolution of FAPbI 3 perovskites during film formation. Herein, a customized crystal surface energy regulation strategy has been innovatively developed by incorporating 0.5 mol % of N‐aminoethylpiperazine hydroiodide (NAPI) additive into α‐FAPbI 3 crystal‐derived perovskite ink, which enabled the formation of highly‐oriented α‐FAPbI 3 films. We deciphered the phase transformation mechanisms and crystallization kinetics of blade‐coated α‐FAPbI 3 perovskite films via combining a series of in‐situ characterizations and theoretical calculations. Interestingly, the strong chemical interactions between the NAPI and inorganic Pb−I framework help to reduce the surface energy of (100) crystal plane by 42 %, retard the crystallization rate and lower the formation energy of α‐FAPbI 3 . Benefited from multifaceted advantages of promoted charge extraction and suppressed non‐radiative recombination, the resultant blade‐coated inverted PSCs based on (100)‐oriented α‐FAPbI 3 perovskite films realized promising efficiencies up to 24.16 % (~26.5 % highe...