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 0.02 cm(2) V-1 s(-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 0.05 cm(2) V-1 s(-1) was obtained by the alignment of the pi-pi intermolecular packing direction parallel to the charge transport direction. (c) 2007 American Institute of Physics.