Two-Dimensional Central Fused Ring Enabled High-Performance Quad-Rotor-Shaped Nonfullerene Acceptor Materials

Nonfullerene acceptor materials (NFAs) have been successfully employed in high-performance organic solar cells (OSCs). However, traditional NFAs, with linear fused-ring cores, often exhibit lower electron affinity and mobility compared with fullerene acceptor materials. In this work, we proposed four two-dimensional NFAs, each shaped like a quad-rotor. These materials feature distinct 2D central fused rings that connect four electron acceptor end groups. Thanks to enhanced molecular conjugation, symmetry, and electron transport channels, these materials showcase outstanding electron affinity, sunlight absorption, exciton separation, and electron transport properties. In particular, for 2DC-ICH and 2DS-ICH, their predicted open circuit voltages even exceed 1.0 V, surpassing typical linear acceptor materials in performance.