Moser, A.; Salzmann, I.; Oehzelt, M.; Neuhold, A.; Flesch, H.-G.; Ivanco, J.; Pop, S.; Toader, T.; Zahn, D.R.T.; Smilgies, D.-M.; Resel, R.: A disordered layered phase in thin films of sexithiophene. Chemical Physics Letters 574 (2013), p. 51-55

This Letter reports the impact of the evaporation rate on the crystallographic phase formation of vacuum deposited alpha-sexithiophene thin films studied by X-ray diffraction methods. The experiments reveal the formation of two crystal phases, one of which is a thermodynamically stable phase occurring at low rates, while the second is favored by high rates. This second phase exhibits an increased layer spacing and diffraction features typical for two-dimensional crystals which are laterally ordered but without interlayer correlations of the molecular positions. This disordered layered phase comprises molecules of nonuniform conformations, and is kinetically induced.