Central Unit Fluorination of Non‐Fullerene Acceptors Enables Highly Efficient Organic Solar Cells with Over 18 % Efficiency. (31st August 2022)

• Record Type: Journal Article
• Authors: Chen, Hongbin; Liang, Huazhe; Guo, Ziqi; Zhu, Yu; Zhang, Zhe; Li, Zhixiang; Cao, Xiangjian; Wang, Haohui; Feng, Wanying; Zou, Yalu; Meng, Lingxian; Xu, Xiaoyun; Kan, Bin; Li, Chenxi; Yao, Zhaoyang; Wan, Xiangjian; Ma, Zaifei; Chen, Yongsheng
• Is Part Of: Angewandte Chemie. Volume 134:Number 41(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-31
• Subjects: Central Unit -- Fluorination -- Non-Fullerene Acceptor -- Solar Cells -- Y-series; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202209580
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Halogenation of terminal of acceptors has been shown to give dramatic improvements in power conversion efficiencies (PCEs) of organic solar cells (OSCs). Similar significant results could be expected from the halogenation of the central units of state‐of‐the‐art Y‐series acceptors. Herein, a pair of acceptors, termed CH6 and CH4, featuring a conjugation‐extended phenazine central unit with and without fluorination, have been synthesized. The fluorinated CH6 has enhanced molecular interactions and crystallinity, superior fibrillar network morphology and improved charge generation and transport in blend films, thus affording a higher PCE of 18.33 % for CH6‐based binary OSCs compared to 16.49 % for the non‐fluorinated CH4. The new central site offers further opportunities for structural optimization of Y‐series molecules to afford better‐performed OSCs and reveals the effectiveness of fluorination on central units. Abstract : A series of CH molecules with a new modification site on the central unit of Y‐series electron acceptors has been designed and synthesized to afford better‐performing organic solar cells (OSCs). Further fluorination on the largely unexplored central unit enabled significantly improved photovoltaic performance with over 18% efficiency for CH6‐based binary OSCs.