Ambipolar field-effect transistors based on polymer semiconductors facilitate the convenient fabrication of low-power complementary organic circuits. However, the species of ambipolar polymer semiconductors are limited; the design and synthesis strategies are scarce. This work demonstrated that bisthiophene-fused diketopyrrolopyrrole (DPPFu) was a wonderful building unit for ambipolar polymer semiconductors. Ambipolar polymer semiconductors could be obtained by copolymerizing DPPFu with both electron-deficient comonomers and electron-rich comonomers. P(DPPFu-T), P(DPPFu-TT) and P(DPPFu-BT) were synthesized by copolymerizing DPPFu with thiophene, thienothiophene and benzothiadiazole, respectively. The structural variation of comonomers allowed for a systematic study on the relationship between comonomer structure, frontier orbital energy level, orbital delocalization index, molecular packing, film morphology and the corresponding charge transport properties. Thienothiophene endowed P(DPPFu-TT) with maximum orientation of edge-on packing. The considerable delocalization extent of the lowest unoccupied molecular orbitals (LUMOs) for P(DPPFu-T) and P(DPPFu-TT) resulted in pronounced electron transport property. P(DPPFu-TT) displayed the best charge transport property with hole mobility up to about 0.1 cm²V⁻¹s⁻¹ and electron mobility of 7.5 × 10⁻² cm²V⁻¹s⁻¹. P(DPPFu-BT) showed ideally balanced charge carrier mobilities for both holes and electrons of 1.6 × 10⁻² cm²V⁻¹s⁻¹ and 1.7 × 10⁻² cm²V⁻¹s⁻¹, respectively. Ion/Ioff ratios of all the ambipolar polymers were above 10³. The ambipolarity of polymer semiconductors was related to not only push-pull electronic characteristics of comonomers, but also the planarity of polymer backbones and delocalization extent of frontier orbitals. Overall, this study provides valuable insights into the design and synthesis of ambipolar polymer semiconductors, which is crucial for the advancement of low-power complementary organic circuits.

基于聚合物半导体的双极场效应晶体管有助于方便地制造低功耗互补有机电路。然而，双极性聚合物半导体的种类有限；设计和合成策略很少。这项工作表明，双噻吩稠合二酮吡咯并吡咯（DPPFu）是双极性聚合物半导体的绝佳构建单元。双极性聚合物半导体可以通过DPPFu与缺电子共聚单体和富电子共聚单体共聚得到。通过DPPFu分别与噻吩、噻吩并噻吩和苯并噻二唑共聚合成P(DPPFu-T)、P(DPPFu-TT)和P(DPPFu-BT)。共聚单体的结构变化允许对共聚单体结构、前沿轨道能级、轨道离域指数、分子堆积、薄膜形态和相应的电荷传输特性。噻吩并噻吩赋予 P(DPPFu-TT) 边缘堆积的最大取向。P(DPPFu-T) 和 P(DPPFu-TT) 的最低未占分子轨道 (LUMO) 的相当大的离域程度导致了显着的电子传输特性。P(DPPFu-TT)表现出最佳的电荷传输性能，空穴迁移率高达约0.1 cm² V ^-1 s ^-1和电子迁移率为7.5×10 ^-2 cm ² V ^-1 s ^-1。P(DPPFu-BT) 表现出理想平衡的空穴和电子载流子迁移率，分别为1.6 × 10 -2 ^cm 2 ^V -1 ^s -1^和1.7 × 10 ^-2 cm ² V ^-1 s ^-1。所有双极性聚合物的 Ion/Ioff 比均高于 10 ³。聚合物半导体的双极性不仅与共聚单体的推挽电子特性有关，还与聚合物主链的平面性和前沿轨道的离域程度有关。总的来说，这项研究为双极性聚合物半导体的设计和合成提供了宝贵的见解，这对于低功耗互补有机电路的进步至关重要。