Releasing Intramolecular Stress of Curved Fused-Core to Enhance N-Type Carrier Transport Performance in A-D-A’-D-A Type Non-Fused Small Molecule

N-type organic semiconductors based on non-fused rings offer concise synthesis routes and low–cost production. Leveraging intramolecular non-covalent interactions, non-fused organic semiconductors can achieve fine regulation of molecular spatial configurations, thereby influencing the electrical performance. Herein, we successfully developed a non-fused n-type organic semiconductor with an A−D-A′-D−A structure, designated as IMIC. Compared to the fused A-DA'D−A molecule, IMIC not only simplifies the synthetic steps but also significantly improves solubility and optical absorption properties. The non-fused molecular architecture relieves the internal stress of rigid, curved polycyclic fused rings, granting greater spatial freedom to the components of the IMIC molecule, which is conducive to optimizing the spatial configuration of the molecule in the aggregated state. Ultimately, the electron mobility of OFET devices based on IMIC is tripled compared to TIIC, reaching 1.1×10⁻³ cm² V⁻¹ s⁻¹ in ambient conditions. © 2025 Wiley-VCH GmbH.