Fused-ring isomerism modulates molecular packing and device performance in non-halogenated organic solar cells.

ABSTRACT: Subtle changes in molecular backbone geometry impact intermolecular interactions and performance of organic solar cells. Here, three isomeric small-molecule acceptors (NaO1, NaO2, and NaO3) are investigated to reveal how different fused-ring configurations control molecular packing, electronic coupling, and film formation. Structural and spectroscopic analyses show that the linearly fused NaO1 forms a compact three-dimensional packing network with large and balanced electronic couplings (>24 meV) across multiple directions, while the more curved analogues exhibit excessive crystallization and phase segregation. In-situ optical measurements demonstrate that NaO1 promotes fast and continuous structural evolution during film formation, resulting in smooth morphology and homogeneous phase dist

SUBMITTER: Zhang J 

PROVIDER: S-EPMC12749161 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature