Benzotriazacycle Cored Perylene Diimide Non-fullerene Acceptors for High-performance Organic Solar Cells

Abstract

Background: Perylene diimide (PDI) is among the most investigated non-fullerene electron acceptor for organic solar cells (OSCs). Constructing PDI derivatives into three-dimensional propellerlike molecular structures is not only one of the viable routes to suppress the over aggregation tendency of the PDI chromophores but also rise possibilities to tune and optimize the optoelectronic property of the molecules. Objective: In this work, we reported the design, synthesis, and characterization of three electronaccepting materials, namely BOZ-PDI, BTZ-PDI, and BIZ-PDI, each with three PDI arms linked to benzotrioxazole, benzotrithiazole, and benzotriimidazole based center cores, respectively. Method: The introduction of electron-withdrawing center cores with heteroatoms does not significantly complicate the synthesis of the acceptor molecules, but drastically influences the energy levels of the propeller-like PDI derivatives. Result: The highest power conversion efficiency was obtained with benzoxazole-based BOZ-PDI reaching 7.70% for its higher photon absorption and charge-transport ability. Conclusion: This work explores the utilization of electron-withdrawing cores with heteroatoms in the propeller-like PDI derivatives, which provides a handy tool to construct high-performance nonfullerene acceptor materials.