Vacuum deposition of oligophenylenes: characterization of textured sexiphenyl deposits by UV-visible and raman scattering spectroscopies

Summary form only given. Sexiphenyl may be vacuum deposited onto glass or silicon oxide substrates. The choice of the deposition parameters allows to obtain textured coatings : substrate temperature above 150/spl deg/ and deposition rate below 1/spl Aring//second were used to get samples in which the long axis of sexiphenyl molecules is perpendicular to the substrate surface (1). Large differences in the UV-visible absorption spectra are evident between textured sexiphenyl samples and amorphous ones : the electronic transitions woth dipolar moment parallel to the chain axis were cancelled in textured samples. These results agree well with IR absorption spectroscopy already published (1). Resonant Raman and IR spectroscopies were used on textured samples with Polarised light to confirm this effect and results will be detailed in this communication.