Conducting polymer polythiophene (PT) film incorporated with C60 was prepared by electrochemical doping and diffusing injection methods. Charge transfer and the molecule-chain interaction were investigated by x-ray photoemission spectroscopy (XPS). Vibration states of the doped C60 and polymer backbone in the hybrid films were also investigated by fourier transform infrared (FTIR) reflaction absorption spectroscopy and FTIR transmission. The XPS spectral profile of the electrochemically doped sample was different from that of the casting sample, which reflects the different dopant-chain interactions in polymer films. The higher binding peaks appearing in the C 1s spectra correspond to C60 and its charged states doped in the polymer, which are closely connected with threefold t(1u) lowest unoccupied molecular orbital and fivefold h(u) higest occupied molecular orbital. FTIR transmission measurements clarified that C60 molecules were doped in the polymer film using both electrochemical doping and casting, as characteristic peaks due to the vibration modes Of C60 were observed. The C60 peaks observed in the spectra for electrochemical doping and casting samples differed, which reflects the different doping states Of C60. The results of XPS and FTIR suggest the conductive state of PT may be controlled by changing the ionic states of C60. (c) 2006 American Vacuum Society.