Anisotropy in the mobility and photogeneration of charge carriers in thin films of discotic hexabenzocoronenes, columnarly self-assembled on friction-deposited poly(tetrafluoroethylene)

Discotic derivatives of hexabenzocoronene macroscopically self-align on friction-deposited poly(tetrafluoroethylene) (see Figure for polarization microscopy image of a partially coated sample). Such films display highly anisotropic photoconductivity with charge transport along the columnar director favored by a factor of at least 20. The anisotropy in the optical absorption depends on the tilt angle of the aromatic core in the columns.