Precisely Manipulating Molecular Packing via Tuning Alkyl Side‐Chain Topology Enabling High‐Performance Nonfused‐Ring Electron Acceptors.

In the development of high‐performance organic solar cells (OSCs), the self‐organization of organic semiconductors plays a crucial role. This study focuses on the precisely manipulation of molecular assemble via tuning alkyl side‐chain topology in a series of low‐cost nonfused‐ring electron acceptors (NFREAs). Among the three NFREAs investigated, DPA‐4, which possesses an asymmetric alkyl side‐chain length, exhibits a tight packing in the crystal and high crystallinity in the film, contributing to improved electron mobility and favorable film morphology for DPA‐4. As a result, the OSC device based on DPA‐4 achieves an excellent power conversion efficiency of 16.67 %, ranking among the highest efficiencies for NFREA‐based OSCs. [ABSTRACT FROM AUTHOR]