不对称菁染料敏化纳米TiO2的光生电流过程

用光电化学方法研究了不对称菁类染料敏化TiO2纳米结构电极的光电转换过程.结果表明,该染料的电子激发态能级位置与TiO2纳米粒子导带边位置匹配较好,光激发染料后,其激发态电子可以注入到TiO2纳米多孔膜的导带,从而使TiO2纳米结构电极的吸收光谱和光电流谱红移至可见光区,其 IPCE(Incident photon-to-electron conversion efficiency)值最高可达84.3%.并进一步结合现场紫外-可见吸收光谱研究了外加电势对激发态染料往TiO2纳米多孔膜注入电子过程的影响.

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.