Solution deposited liquid crystalline semiconductors on a photoalignment layer for organic thin-film transistors

Highly ordered liquid crystalline semiconductors on a light induced alignment layer results in an anisotropic electrical characteristic and an enhanced mobility of solution processed thin-film transistors. In the case of poly-$9,9′$-dioctyl-fluorene-co-bithiophene, a mobility as high as $0.02cm2V−1s−1$ has been achieved by aligning a polymer chain parallel to the charge transport direction. Using an oligomeric semiconductor, $5,5′$-bis(4-octyloxyphenyl)bithiophene, an enhanced mobility of $0.05cm2V−1s−1$ was obtained by the alignment of the $π-π$ intermolecular packing direction parallel to the charge transport direction.