Molecular orientation and anisotropic carrier mobility in poorly soluble polythiophene thin films

Oriented thin films of a poorly soluble polythiophene, poly[benzo[1,2-d: 4,5-d'] bisthiazole-2,6-diyl (3',4,4 '',4'''-tetradodecyl[2,2': 5',2 '': 5 '',2'''-quaterthiophene]-5,5'''-diyl)], were fabricated using the friction-transfer technique. The detail of the film structure was investigated using polarized UV-vis spectroscopy, transmission electron microscopy, and grazing-incidence x-ray diffraction observations. The friction-transfer technique enables control of the anisotropic carrier transport according to the face-on and/or edge-on molecular orientations in films with one-directionally aligned polymer backbones. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4718424]