Manipulating Alkyl Inner Side Chain of Acceptor for Efficient As‐Cast Organic Solar Cells

• DOI: 10.1002/adma.202405718
• Publication Date: 2024-07-17T05:44:32Z
• Authors: Bao Zhang; Mengyun Jiang; Peng Mao; Shanshan Wang; Ruohua Gui; Yingqi Wang; Han Young Woo; Hang Yin; Jin‐Liang Wang; Qiaoshi An
• Keywords: Side chain; Acceptor

As-cast organic solar cells (OSCs) possess tremendous potential for low-cost commercial applications. Herein, five small-molecule acceptors (A1-A5) are designed and synthesized by selectively elaborately extending the alkyl inner side chain flanking on pyrrole motif to prepare efficient as-cast devices. As extension of chain, absorption spectra films gradually blue-shifted from A1 A5 along with slightly uplifted lowest unoccupied molecular orbital energy levels, which is conducive optimizing trade-off between short-circuit current density open-circuit voltage Moreover, a longer improves compatibility acceptor donor. The in situ technique clarifies that good will prolong assembly time assist preferential formation donor phase, where precipitates framework formed corresponding film-formation dynamics facilitate realization favorable film morphology suitable fibrillar structure, stacking, vertical phase separation, resulting an incremental fill factor A5-based Consequently, A3-based OSCs achieve top-ranked efficiency 18.29%. This work proposes ingenious strategy manipulate intermolecular interactions control process constructing high-performance