ORGANIC PHOTOCONDUCTORS AND C-60

We report experimental results on photoelectron spectroscopy (XPS, UPS ) and X-ray absorption near edge spectroscopy (XANES) from poly(3-octy lthiophene) (P30T) and Cu-phthalocyanine (Cu-Pc) in contact with C-60. The interaction between these organic photoconductors and the C-60 is rather weak. At room temperature an inter-diffusion between C-60 and P30T is observed, whereas Cu-Pe and C-60 build a stable interface. The spectra reveal the relative positions of the electronic levels close to the optical gap. From this we conclude that an electron transfer to C-60 via some excitonic states of the photoconductor is energetically possible. Cu-Pc exhibits a band-bending induced by C-60 as deduced fr om the observed shifts in the XPS and UPS spectra and the missing shif ts in the XANES spectra.