An Asymmetric Furan/Thieno[3,2‐b]Thiophene Diketopyrrolopyrrole Building Block for Annealing‐Free Green‐Solvent Processable Organic Thin‐Film Transistors

Abstract A new asymmetric furan and thieno[3,2‐ b ]thiophene flanked diketopyrrolopyrrole ( TTFDPP ) building block for conjugated polymers is designed and used to generate a donor–acceptor semiconducting polymer, poly[3‐(furan‐2‐yl)‐2,5‐bis(2‐octyldodecyl)‐6‐(thieno[3,2‐ b ]thiophen‐2‐yl)pyrrolo[3,4‐ c ]pyrrole‐1,4(2 H ,5 H )‐dione‐ alt ‐thieno[3,2‐ b ]thiophene] (abbreviated to PTTFDPP‐TT) , consisting of TTFDPP unit copolymerized with thieno[3,2‐ b ]thiophene comonomer ( TT ), which is further synthesized. Results demonstrate that PTTFDPP‐TT‐ based thin‐film transistors in a bottom‐gate bottom‐contact device configuration exhibit typical hole‐transporting property, with weak temperature dependence for charge carrier mobility from room temperature to 200 °C. In addition, the good solubility of PTTFDPP‐TT due to the incorporation of a polar furan unit and an asymmetric conjugated structure makes it able to be solution processed with a less toxic nonchlorinated solvent such as toluene, demonstrating comparable performance with that prepared from chlorinated solution. These results suggest PTTFDPP‐TT as a promising organic semiconductor candidate for annealing‐free, environmentally benign, and less energy‐consuming applications in large‐area flexible organic electronic devices.