Precisely Regulating Intermolecular Interactions and Molecular Packing of Nonfused-Ring Electron Acceptors via Halogen Transposition for High-Performance Organic Solar Cells

The structure of molecular aggregates is crucial for charge transport and photovoltaic performance in organic solar cells (OSCs). Herein, the intermolecular interactions and aggregated structures of nonfused-ring electron acceptors (NFREAs) are precisely regulated through a halogen transposition strategy, resulting in a noteworthy transformation from a 2D-layered structure to a 3D-interconnected packing network. Based on the 3D electron transport pathway, the binary and ternary devices deliver outstanding power conversion efficiencies (PCEs) of 17.46 % and 18.24 %, respectively, marking the highest value for NFREA-based OSCs. Herein, we propose a novel halogen transposition strategy aimed at precisely regulate the intermolecular interactions and aggregated structures of nonfused-ring electron acceptors (NFREAs). Hence, the NFREA 3TTB-ClF, featuring a 3D-interconnected packing network, achieves outstanding power conversion efficiencies of 17.46 % and 18.24 % in binary and ternary organic photovoltaic devices, respectively, marking a new milestone in the field of NFREA-based organic solar cells. image