Optical properties, morphology and structure of high quality oligothiophene films grown by supersonic seeded beams

We show that seeded supersonic beam epitaxy (SuMBE) allows a high degree of control on the morphology and structure of organic pi -conjugated oligomers, as previously proposed.:Here, we report on the growth of alpha -quaterthiophene films and demonstrate that, by changing the beam's parameters, one can reliably prepare films hundreds of nanometers thick characterized by different optical properties. The correspondence of the different low temperature photoluminescence spectra, which characterize films grown by beams with different parameters, to different possible structures and morphologies is discussed and compared with results reported in literature on very thin films and single crystals. (C) 2001 Elsevier Science B.V. All rights reserved.