Organic semiconductors that can be fabricated by simple processing techniques and possess excellent electrical performance, are key requirements in the progress of organic electronics. Both high semiconductor charge-carrier mobility, optimized through understanding and control of the semiconductor microstructure, and stability of the semiconductor to ambient electrochemical oxidative processes are required. We report on new semiconducting liquid-crystalline thieno[3,2-b ]thiophene polymers, the enhancement in charge-carrier mobility achieved through highly organized morphology from processing in the mesophase, and the effects of exposure to both ambient and low-humidity air on the performance of transistor devices. Relatively large crystalline domain sizes on the length scale of lithographically accessible channel lengths (∼200 nm) were exhibited in thin films, thus offering the potential for fabrication of single-crystal polymer transistors. Good transistor stability under static storage and operation in a low-humidity air environment was demonstrated, with charge-carrier field-effect mobilities of 0.2–0.6 cm2 V−1 s−1 achieved under nitrogen.
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Portions of this research were carried out at the Stanford Synchrotron Radiation Laboratory, a user facility operated by Stanford University on behalf of the US Department of Energy, Office of Basic Energy Sciences.
The authors declare no competing financial interests.
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McCulloch, I., Heeney, M., Bailey, C. et al. Liquid-crystalline semiconducting polymers with high charge-carrier mobility. Nature Mater 5, 328–333 (2006). https://doi.org/10.1038/nmat1612
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