Spacer isomerization engineering: a key strategy for high-performance single-component organic solar cells

The performance of single-component organic solar cells is highly dependent on spacer. However, the role of spacer attachment position—a critical structural parameter of double-cable polymers—remains understudied.

To fill this research gap, we proposed a spacer isomerization engineering strategy and synthesized two isomeric double-cable polymers by regulating the attachment position of the spacer on the indenone benzene ring. This precise structural regulation not only effectively optimizes molecular packing and film crystallinity—two core factors critical for enhancing exciton dissociation efficiency, charge transport performance, and power conversion efficiency (PCE) in single-component organic solar cells (SCOSCs)—but also delivers remarkable performance when employed as the third component in ternary systems, which refines the donor-acceptor interface. Notably, these polymers exhibit excellent thermal stability regardless of their application scenario, whether integrated into SCOSCs or utilized as the third component in ternary devices.

This work highlights spacer isomerization engineering as a simple and effective strategy, offering valuable insights for the rational design of high-performance and stable SCOSCs. The work titled “Spacer isomerization engineering in double-cable conjugated polymers for optimized molecular packing and enhanced photovoltaic performance” was published on Acta Physico-Chimica Sinica (published on December 11, 2025).