Organic molecular beam deposition (OMBD) enables the fabrication of or
ganic materials with controlled and reproducible electronic and optica
l properties. For electronic and photonic applications of organic mate
rials, poly- and oligothiophenes are among the most interesting. Here
the growth of highly oriented films of beta-tetrahexylsexithiophene by
OMBD onto an organic ionic crystal substrate is reported. Analysis of
UV-vis absorption spectra demonstrates a clear relationship between t
he ordered structure of the film and the crystal lattice of the substr
ate.