Synergistic Quaternary Polymerization Strategy for Highly Efficient and Reproducibility Polymer Solar Cells

Abstract

To overcome the limitations of batch-to-batch variations and donor material robustness in polymer solar cells (PSCs), we designed quaternary (H1–H9), ternary (H10–H15), and binary (PM6, PBQ10, PBDS-T) polymer donors via precise monomer ratio modulation. Due to the synergistic coordination among multiple components, the H4-based blend film demonstrated enhanced intermolecular interactions and provides additional low-energy-barrier pathways for efficient charge carrier transport. After blending with L8-BO, the H4-based films displayed a more desirable morphology and effective charge carrier transport than the categories. As a result, the H4:L8-BO-based PSCs achieved impressive power conversion efficiency (PCE) of 19.66% for binary device and 20.34% for ternary device. Besides, the introduced functional groups disrupt the regularity of the matrix polymer main chain, leading to stable and robust film morphologies. Consequently, the H4:L8-BO-based blend film not only demonstrates improved mechanical robustness, with a crack onset strain (COS) of 17.8%, and maintains a PCE of 16.35% in flexible devices, but also exhibits excellent batch-to-batch stability with significant variations in molecular weight. This work presents a strategy to simultaneously enhance device performance, mechanical robustness, and reproducibility through quaternary copolymerization, enabling controlled crystallinity and additional multichannel charge transport.

Keywords

mechanical robustness / multichannel charge transport / polymer donors / quaternary copolymerization / reproducibility

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2026 The Author(s). Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.