The development of high‐performance ambipolar polymer semiconductors is critical to organic electronics. Herein, isoindigo (IID)‐based copolymers PIIDDTBT and PIIDDTffBT are synthesized and characterized. Both polymers have suitable highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels for hole and electron injection. Density functional theory calculation reveals F⋯S intramolecular interactions are formed in PIIDDTffBT, which locks the molecular conformation and leads to a more planar backbone. Thin film transistor characterization shows both polymers display ambipolar charge carrier transport behavior. The hole/electron mobilities are 0.29/0.1 cm2 V−1 s−1 for PIIDDTffBT and 0.053/0.013 cm2 V−1 s−1 for PIIDDTBT in the bottom‐gate/top‐contact (BGTC) device structures. The hole/electron mobilities of PIIDDTffBT are one of the highest values for IID‐based ambipolar polymer transistors in BGTC device structure. Atomic force microscopy and X‐ray diffraction results reveal PIIDDTffBT films have higher film quality, crystallinity, and more ordered microstructures, being ascribed to the F⋯S interactions locked backbone. These results demonstrate that the introduction of F⋯S interactions is an effective strategy to design high‐performance ambipolar polymer semiconductors.

It is a great challenge to design n-channel donor-acceptor (DÀ A) type small molecules because of the lack of strong electron withdrawing acceptor unit. Herein, 3-(dicyanomethylidene)-indan-1-one (IC) and 1,3-bis(dicyanomethylidene)-indene (IDC) based DÀ A type small molecular organic semiconductors IC-DDTPTI and IDC-DDTPTI are synthesized and characterized. Both compounds have low-lying LUMO energy levels, especially for IDC-DDTPTI with LUMO energy level lower than À 4.0 eV.Thin film transistor characteristics show IC-DDTPTI displays ambipolar transistor behavior with balanced hole and electron mobility. The electron mobility is 0.40 cm 2 V À 1 s À 1 and the hole mobility reaches 0.18 cm 2 V À 1 s À 1 . IDC-DDTPTI exhibits unipolar n-channel character with an electron mobility of 0.027 cm 2 V À 1 s À 1 . These results highlight the applications of IC and IDC units in high performance DÀ A type n-channel organic semiconductors.

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