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 oligomer s, as previously proposed.:Here, we report on the growth of alpha -quaterth iophene films and demonstrate that, by changing the beam's parameters, one can reliably prepare films hundreds of nanometers thick characterized by di fferent optical properties. The correspondence of the different low tempera ture photoluminescence spectra, which characterize films grown by beams wit h different parameters, to different possible structures and morphologies i s discussed and compared with results reported in literature on very thin f ilms and single crystals. (C) 2001 Elsevier Science B.V. All rights reserve d.