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.