Synergetic Evolution of Diketopyrrolopyrrole‐Based Polymeric Semiconductor for High Reproducibility and Performance: Random Copolymerization of Similarly Shaped Building Blocks
A new random copolymer consisting of similarly shaped donor–acceptor building blocks of diketopyrrolopyrrole‐selenophene‐vinylene‐selenophene (DPP‐SVS) and DPP‐thiophene‐vinylene‐thiophene (DPP‐TVT) is designed and synthesized. The resulting P‐DPP‐SVS(5)‐TVT(5) with an equal molecular ratio of the two building blocks produced significantly enhanced solubility when compared to that of the two homopolymers, PDPP‐SVS and PDPP‐TVT. More importantly, despite the maximum segmental randomness of the PDPP‐SVS(5)‐TVT(5) copolymer, its crystalline perfectness and preferential orientation are outstanding, even similar to those of the homopolymers thanks to the similarity of the two building blocks. This unique property produces a high charge carrier mobility of 1.23 cm2 V−1 s−1 of PDPP‐SVS(5)‐TVT(5), as determined from polymer field‐effect transistor (PFET) measurements. The high solubility of PDPP‐SVS(5)‐TVT(5) promotes formulation of high‐viscosity solutions which could be successfully processed to fabricate large‐areal PFETs onto hydrophobically treated 4 in. wafers. A total of 269 individual PFETs are fabricated. These devices exhibit extremely narrow device‐to‐device deviations without a single failure and demonstrate an average charge carrier mobility of 0.66 cm2 V−1 s−1 with a standard deviation of 0.064. This is the first study to report on successfully realizing large‐areal reproducibility of high‐mobility polymeric semiconductors.