Over 13% Efficient Single‐Component Organic Solar Cells Enabled by Adjusting the Conjugated‐Length of Intermediate PBDB‐T Block

Abstract Batch‐to‐batch variation widely exists in conjugated donor‐acceptor (D‐A) block copolymer materials and plays a crucial role in photovoltaic performance of organic solar cells (OSCs). To investigate the influence of conjugated‐length of the intermediate block on the performance of single‐component OSC (SCOSCs), herein, four batches of conjugated block copolymers (CBCs, PB‐ b ‐PY‐1, PB‐ b ‐PY‐2, PB‐ b ‐PY‐3, and PB‐ b ‐PY‐4) are synthesized, which possess different D/A block lengths. As the conjugation length of intermediate D‐block increases, the lamellar packing order of these CBCs shows a monotonically increasing trend, leading to stronger absorption spectra in the visible region, efficient charge transfer, and suppressed carrier recombination loss. Consequently, the PB‐ b ‐PY‐4 device yields a higher efficiency of 13.28% than those of other CBCs. This study demonstrates the effectiveness of the conjugated length of intermediate D‐blocks in designing high‐performance conjugated D‐A block copolymers, which paves the way toward developing high‐performance SCOSCs.