Organic Molecular Beam Deposition of α-Sexithienyl

We fabricated the molecular-oriented thin films of alpha-sexithienyl (6T) by an organic molecular beam deposition (OMBD) technique. The molecular orientations were evaluated from electronic spectra. The 6T molecules were aligned almost exactly parallel to the surface normal in the film deposited at a low deposition rate under 10(-9) Torr. Furthermore, the GT molecules in the film fabricated under 10(-9) Torr have been found to form uniform aggregates. The aggregation has been analyzed by a molecular exciton model to give the molecular tilt angle of 85.7-degrees.