Quasi-epitaxial growth of quaterthiophene thin films by organic molecular beam deposition

A study of thin films of quaterthiophene grown by organic molecular beam deposition on different substrates under highly controlled growth conditions is presented. Polarized absorption measurements reveal a complete macroscopic orientation of the films deposited on potassium acid phtalate (KAP) single crystals. X-ray diffraction measurements have been performed on films deposited on different substrates and the results interpreted in relation with the optical properties. Epitaxial growth is demonstrated for the films deposited on KAP combining the results of optical and structural analysis.