Femtosecond Transient Absorption Spectroscopy in alpha-sexithienyl thin films

he electroactive and photoactive properties of conjugated systems have attracted the interest of many laboratories, both for a basic understanding of their photophysics as well as for possible applications in organic-based optoelectronic devices, ?-sexithienyl has been recognized as a model compound for a basic understanding of the electronic properties of conjugated materials. We report on ultrafast pump-probe measurements on ultra-high vacuum deposited thin films of ?-sexithienyl, Femtosecond transient spectroscopy experiments were performed at low temperatures and over a wide wavelength range of the probe beam (from 420 nm up to 680 nm). The dynamics of the photoexcited species are discussed in the frame of the excitonic model.