description
- This project aims to develop new generation of composite material based on TiO2 nanotubes and intrinsically conductive polymer (ICP) deposited in nanotube framework. Our objective is to combine of electrical conductivity of ICP and UV sensitivity of TiO2. Particularly, dye sensitization of TiO2 in conjunction with ICP is of our interest. It is expected that high surface area morphology offered by high aspect ratio nanotube system, which provide extremely high TiO2/ICP interface, will play the key role in specific interaction between conductive polymer and wide band-gap semiconductor. Remarkable electric and optical properties of new composite material are expected. A variety of polymer dopants, electrochemical conditions, and electropolymerization methods will be applied in order to find electrochemical route for successful, homogeneous deposition of ICP`s in TiO2 nanotube system. Two conductive polymers will be electrosynthesized in nanotube framework: poly-3,4-ethylenedioxytiophene (PEDOT) and poly-3-hexyltiophene (P3HT). The p-n junction, which is expected at the polymer-semiconductor interface, will be electrochemically controlled by switching polymer between oxidizing and reducing state. PEDOT will be tested as a p-type electrolyte in dye sensitized solar cell device Ti/TiO2/ruthenium-based-dye/PEDOT. P3HT absorbs visible light and thus may replace the dye and the electrolyte, giving the function of charge transport and light absorption. The effects of nano-architecture of the Ti/TiO2/P3HT composite material will be studied in order to meet the dimension of phase separation within the exiton diffusion length of the polymer. Above features make the new composite material very attractive for applications including solar cells and electro-chromic devices. Furthermore, improved bio-compability of the material should find practical applications in biomedicine systems. This project will be taken in close collaboration of Hokkaido University and University of Erlangen.