A Highly Planar Nonfullerene Acceptor with Multiple Noncovalent Conformational Locks for Efficient Organic Solar Cells

Abstract A novel nonfullerene small‐molecular acceptor indacenodithiophene (IDT)‐4CN is designed and synthesized with IDT as the core and benzothiadiazole and dicyanoethxylrhodanine as end‐capping groups. Multiple noncovalent conformational locks N…S, CH…O, and CH…N are introduced into the backbone, resulting in a highly planar molecular acceptor. As a result, the IDT‐4CN‐based organic solar cells exhibit a power conversion efficiency of 8.13%, which is much higher than that of PC71BM‐based devices (6.19%). A novel method is thus demonstrated to construct highly planar molecular acceptors for organic solar cells.