LAUSR

The development of unipolar n‐type semiconducting polymers with electron mobility (µe) over 5 cm2 V−1 s−1 remains a massive challenge in organic semiconductors. Diketopyrrolopyrrole (DPP) has proven to be a successful unit for high‐performance p‐type and ambipolar polymers. However, DPP's moderate electron‐accepting capability leads to the shallow frontier molecular orbital (FMO) levels of the resultant polymers and hence limit the µe in unipolar n‐type organic transistors. Herein, this issue has been addressed by using a hybrid acceptor‐modulation strategy based on DPP‐containing “fluorinated triple‐acceptor architecture”, namely DPP‐difluorobenzothiadiazole‐DPP (DFB). Compared with DFB's non‐fluorinated counterpart, DFB features deeper FMO levels and a shape‐persistent framework. Therefore, a series of DFB‐based polymers demonstrate planar backbones and lowered FMO levels by ≈0.10 to 0.25 eV versus that of the control polymer. Intriguingly, all DFB‐polymers exhibit excellent unipolar n‐type transistor performances. Notably, a full‐locked backbone conformation and high crystallinity with crystalline coherence length of 524 Å are observed for pDFB‐TF, accounting for its high µe of 5.04 cm2 V−1 s−1, which is the highest µe value for DPP‐based unipolar n‐type polymers reported to date. This work demonstrates that the strategy of “fluorinated triple‐acceptor architecture” opens a new path towards high‐performance unipolar n‐type semiconducting polymers.