Oriented sexiphenyl single crystal nanoneedles on TiO2 (110)

Para-sexiphenyl is found to assemble into azimuthally oriented crystalline nanoneedles on a TiO2 substrate (see Figure). The needles grow after prolonged exposure until they completely tile the surface with a film of uniform thickness. This novel morphology combined with the unique orientation of the molecules (all parallel to each other and the substrate and all with their molecular planes tilted with respect to the substrate) appears useful for both light-emitting diodes and field-effect transistor applications.