Nanoscale patterning of a conjugated oligomer

Vapor-deposited alpha-sexithiophene is finding important organic electronic device applications. A method of patterning dibutylphosphonate-substituted sexithiophene (DBP-alpha 6T), a soluble version of this conjugated oligomer, with lateral dimensions as small as 50 nm is described. It consists of using either microcontact printing or dip-pen nanolithography to form hydrophilic alkanethiol patterns on a gold surface. The remainder of the surface is backfilled with a hydrophobic alkanethiol. When DBP-alpha 6T is spin-coated and annealed, it preferentially adsorbs on the hydrophilic patterns. Photoemission demonstrates the similarity in valence electronic structure of DBP-alpha 6T films to alpha-sexithiophene. This patterning method may be useful for future nanoscale device fabrication.