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Conducting polymer polythiophene (PT) films incorporated with copper phthalocyanine (CuPc) or fullerene C60 or both molecules together were synthesized and characterized by photoluminescence measurements. The hybrid materials were also modified by electrochemically applying positive or negative voltage or by adding the donor molecule tetrathiafulvalene (TTF) or acceptor molecule tetracyanoquinodimethane (TCNQ) into the hybrid films and were investigated by photoluminescence measurements in order to obtain fundamental photoluminescence properties of the hybrid materials. The molecule was injected by electrochemical and diffusion methods. A photoluminescence emission peak was observed at 594 nm in the case of a PT sample doped with CuPc by the diffusion method. Adding C60 molecules to the CuPc diffused PT sample by the diffusion method made the emission peak shift to the higher wavelength at 730 nm, suggesting the molecular interaction between the polymer chain and C60 in the photoluminescence emission process because double emission peaks were observed at 590 and 735 nm in the case of single doping of C60. Electrochemically applying voltages to the films or adding donor molecule TTF and acceptor molecule TCNQ to the polymer hybrid films caused the photoluminescence peak shifts, loss, and enhancement. The present study showed the possibility of control of photoluminescence wavelength of the hybrid films.

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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 t1u lowest unoccupied molecular orbital and fivefold hu 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.

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