Photogenerated Current Process of TiO2 Nanostructured Electrode Sensitized by Unsymmetrical Cyanine Dye

The light-to-electricity conversion process of the TiO2 nanostructured electrode sensitized by an unsymmetrical cyanine dye (noted as CD) was investigated using the photoelectron chemical method. The results showed that the excited state level of the dye well matched the conduction band edge of TiO2 nanoparticles and the electron of the excited dye could be injected into the conduction band of TiO2 nanoparticles. A red-shift was observed in both the optical absorption and photocurrent spectra of the sensitized TiO2 nanostructured electrode compared with the unsensitized TiO2 nanostructured electrode. The maximum value of IPCE reached 84.3%. The process for the injection of electron into the TiO2 nanoporous film from the excited dye was studied with in situ spectroelectrochemistry. The results showed that the above process could be influenced by externally applied potential.