An A-D-A′-D-A type unfused nonfullerene acceptor for organic solar cells with approaching 14% efficiency

In recent years, power conversion efficiency (PCE) of organic solar cells (OSCs) has made significant improvement. A large number of studies were reported to achieve high PCEs through exploring new active layer materials, especially the high efficiency fused ring acceptors (FRAs). Compared with FRAs, another type of so-called unfused-ring acceptors (UFAs), possessing some advantages such as simple synthesis and low cost, have attracted a lot of attention. Herein, a new UFA BTzO-4F, incorporating with a benzotriazole moiety and SMIDLINE HORIZONTAL ELLIPSISO intramolecular noncovalent interactions, has been successfully synthesized. The photovoltaic device based on PBDB-T:BTzO-4F achieved a record PCE of 13.8% for UFAs, which indicates that introducing the benzotriazole moiety is an effective strategy for high quality acceptors. Thus, these findings of this work demonstrate the great potential of UFAs for high performance OSCs.

Automated summary

In recent years, significant improvements have been made in the power conversion efficiency (PCE) of organic solar cells (OSCs) by exploring new active layer materials, especially high efficiency acceptors. Unfused-ring acceptors (UFAs) have attracted attention for their advantages of simple synthesis and low cost compared to fused-ring acceptors. The synthesis of a new UFA BTzO-4F incorporating benzotriazole moiety and intramolecular noncovalent interactions has led to a record PCE of 13.8% for UFAs, demonstrating the great potential of UFAs for high performance OSCs.