In situ optical investigation of oligothiophene layers grown by organic molecular beam epitaxy

Reflectance anisotropy spectroscopy (RAS) has recently been used to monitor in situ and in real time the growth of thin organic layers in ultra high vacuum (UHV) (Goletti et al 2003 Appl. Phys. Lett. 83 4146). In this paper, after a short discussion of RAS, with particular attention to the application to organics, we present recent results on the deposition of ordered oligothiophene films by organic molecular beam epitaxy (OMBE), namely α-sexithiophene and quaterthiophene films onto potassium acid phthalate substrates