High‐Performance Nonfused Ring Electron Acceptors with V‐Shaped Side Chains

Abstract

Motivated by simplifying the synthesis of nonfullerene acceptor and establishing the relation between molecular structure and photovoltaic performance, two isomeric nonfused ring electron acceptors (o-TT-Cl and m-TT-Cl), whose properties can be adjusted by changing the side chains, are designed and synthesized with several high-yield steps. o-TT-Cl with V-shaped side chain induces a dominated J-aggregation and displays much better solubility and more ordered packing than m-TT-Cl with linear side chain. Thus, the o-TT-Cl-based blend film generates better phase morphology and charge transport than m-TT-Cl-based one. Finally, the power conversion efficiency of o-TT-Cl-based devices is 12.84%, which is much higher than that of m-TT-Cl-based ones (6.54%). This work highlights the importance of side chains engineering on improving photovoltaic performance of nonfused ring electron acceptors.