Nonfullerene acceptors with a novel nonacyclic core for high-performance polymer solar cells

We developed two new fused-ring electron acceptors (FREAs) (IDIDTT and IDIDTT-2F) with a nonacyclic core, which bears eight side chains. The rigid coplanar nonacyclic core structure could broaden the absorption to the near-infrared (NIR) region, reduce the nonradiative energy loss, and enhance the charge transport. Pairing with PBDB-T, polymer solar cells were fabricated and investigated. IDIDTT-2F-based optimized devices showed a power conversion efficiency (PCE) of 11.29% with a V-oc of 0.92 V, J(sc) of 19.79 mA cm(-2), and FF of 61.85%. Our results showed that FREAs with the nonacyclic core could be promising in achieving high performance polymer solar cells.