The Q-CdS, Q-PbS quantum dot were formed in situ on the nanocrystalline TiO₂ electrode using chemical bath deposition techniques and the poly(3-methylthiophene) (PMeT) was prepared with electrochemical method on TiO₂/Q-CdS (Q-PbS) film. The photoelectrochemical properties of PMeT modified Q-CdS, Q-PbS anchored nanostructured TiO₂ film were studied by photoelectruchemical method. The results indicated that PMeT, Q-CdS and Q-PbS modified TiO₂ film and PMeT modified Q-CdS, Q-PbS anchored nanostructured TiO₂ film produced photocurrent in the longer wavelength region under certain condition. In infrared light region, the conversion efficiency of light to electricity for the composite semiconductor nanoporous films was greatly improved compared with that of the nanostructured TiO₂. The experiment result showed that the p-n heterojunction existed in the nanostructure TiO₂/Q-CdS (Q-PbS)/PMeT film electrode, which favored the separation of electron/hole pairs generated by photoexcitation. It cound be seen that the maximum value of incident photon to current conversion of efficiency (IPCE) for PMeT modified Q-CdS, Q-PbS anchored nanostructured TiO₂ film was 11% and 7% respectively.

Key words: quantum dot, TiO₂ nanoporous film electrode, poly(3-methylthiophene), photoelectrochemistry