Carboxylating Elastomer via Thiol‐Ene Click Reaction to Improve Miscibility with Conjugated Polymers for Mechanically Robust Organic Solar Cells with Efficiency of 19%

Journal Article · Tue Feb 13 00:00:00 EST 2024 · Advanced Materials

DOI:https://doi.org/10.1002/adma.202312805· OSTI ID:2301733

Zhang, Junjie ^[1]; Chen, Qiaomei ^[1]; Li, Mengdi ^[2]; Zhang, Guangcong ^[1]; Zhang, Zhou ^[1]; Deng, Xiangmeng ^[2]; Xue, Jingwei ^[3]; Zhao, Chaowei ^[2]; Xiao, Chengyi ^[1]; Ma, Wei ^[3]; Li, Weiwei  ^[1]

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1. Beijing Advanced Innovation Center for Soft Matter Science and Engineering &, State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing 100029 P. R. China
2. Institute of Applied Chemistry Jiangxi Academy of Sciences Nanchang 330096 P. R. China
3. State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an 710049 P. R. China

Abstract Incorporating flexible insulating polymers is a straightforward strategy to enhance the mechanical properties of rigid conjugated polymers, enabling their use in flexible electronic devices. However, maintaining electronic characteristics simultaneously is challenging due to the poor miscibility between insulating polymers and conjugated polymers. This study introduces the carboxylation of insulating polymers as an effective strategy to enhance miscibility with conjugated polymers via surface energy modulation and hydrogen bonding. The carboxylated elastomer, synthesized via a thiol‐ene click reaction, closely matches the surface energy of the conjugated polymer. This significantly improves the mechanical properties, achieving a high crack‐onset strain of 21.48%, surpassing that (5.93%) of the unmodified elastomer:conjugated polymer blend. Upon incorporating the carboxylated elastomer into PM6:L8‐BO‐based organic solar cells, an impressive power conversion efficiency of 19.04% is attained, which top‐performs among insulating polymer‐incorporated devices and outperforms devices with unmodified elastomer or neat PM6:L8‐BO. The superior efficiency is attributed to the optimized microstructures and enhanced crystallinity for efficient and balanced charge transport, and suppressed charge recombination. Furthermore, flexible devices with 5% carboxylated elastomer exhibit superior mechanical stability, retaining ≈88.9% of the initial efficiency after 40 000 bending cycles at a 1 mm radius, surpassing ≈83.5% for devices with 5% unmodified elastomer.

• Sponsoring Organization: USDOE
• Grant/Contract Number: DE‐AC02‐05CH11231
• OSTI ID: 2301733
• Journal Information: Advanced Materials, Journal Name: Advanced Materials; ISSN 0935-9648
• Publisher: Wiley Blackwell (John Wiley & Sons)
• Country of Publication: Germany
• Language: English