We report isoindigo based copolymers, poly(isoindigo benzodifurandione-bithiophene-alkoxyl) (PIBDF-BTO) and poly(isoindigo-bithiophene-alkoxyl) (PI-BTO) for high performance organic field-effect transistors (OFETs). PIBDF-BTO was synthesized by introducing strong electron withdrawing BDF into the acceptor isoindigo unit of PI-BTO to deepen the polymer highest occupied molecular orbital and the lowest unoccupied molecular orbital. This modification provided better polymer chain crystallinity and connectivity in thin film through increased intermolecular interactions and larger co-planarity in PIBDF-BTO. X-ray diffraction and atomic force microscopy showed higher crystallinity and well-arranged nano-fibril morphological PIBDF-BTO film compared with PI-BTO film. PIBDF-BTO OFETs showed much higher field effect mobility with well-balanced ambipolar transport with hole and electron mobilities of 0.27 and 0.22 cm² V⁻¹ s⁻¹ compared to PI-BTO OFETs with hole mobility 0.004 cm² V⁻¹ s⁻¹ and very low electron mobility. PIBDF-BTO also showed better hole and electron injection properties due to the narrower band gap (0.97 eV) compared to PI-BTO (1.35 eV). PI-BTO and PIBDF-BTO OFETs were operationally stable with negligible threshold voltage shift after continuous cycling measurements.

中文翻译：

---

基于异靛蓝苯并二呋喃二酮的共轭聚合物，用于高性能有机场效应晶体管†

我们报告了基于异靛蓝的共聚物，用于高性能有机场效应晶体管（OFET）的聚（异靛蓝苯并二呋喃二酮-联噻吩-烷氧基）（PIBDF-BTO）和聚（异靛蓝-联噻吩-烷氧基）（PI-BTO）。PIBDF-BTO是通过将强吸电子的BDF引入PI-BTO的受体异靛蓝单元中以加深聚合物的最高占据分子轨道和最低未占据分子轨道而合成的。这种修饰通过增加分子间的相互作用和PIBDF-BTO中更大的共面性，在薄膜中提供了更好的聚合物链结晶性和连接性。与PI-BTO膜相比，X射线衍射和原子力显微镜显示出更高的结晶度和排列良好的纳米原纤维形态PIBDF-BTO膜。² V ^-1小号^-1相比PI-BTO的OFET与空穴迁移率0.004厘米² V ^-1小号^-1和非常低的电子迁移率。由于PIBDF-BTO的带隙（0.97 eV）比PI-BTO（1.35 eV）窄，因此还显示出更好的空穴和电子注入性能。连续循环测量后，PI-BTO和PIBDF-BTO OFET运行稳定，阈值电压漂移可忽略不计。