香豆素染料敏化纳米晶TiO₂电极中的电子传输

Electron transport in coumarin-dye-sensitized nanocrystalline TiO2 electrodes.

作者信息

Hara Kohjiro, Miyamoto Koji, Abe Yoshimoto, Yanagida Masatoshi

机构信息

National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.

出版信息

J Phys Chem B. 2005 Dec 22;109(50):23776-8. doi: 10.1021/jp055572q.

DOI:10.1021/jp055572q

PMID:16375359

Abstract

We investigated electron transport kinetics in terms of electron diffusion coefficient (D) and electron lifetime (tau) in coumarin-dye-sensitized nanocrystalline TiO2 electrodes by intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS). We found that the values of tau for coumarin-dye-sensitized TiO2 electrodes were much shorter than that for an electrode coated with a Ru complex (N719 dye), suggesting that the back-electron-transfer process corresponding to recombination between conduction-band electrons in the TiO2 and I3- ions in the electrolyte occurs more easily in coumarin-dye-sensitized solar cells. In addition, the values of tau depended on the kind of coumarin dye, each of which has a different number of thiophene moieties, suggesting that the molecular structure of the adsorbed dyes also affects the kinetics of electron transport in the TiO2 electrodes.

摘要

我们通过强度调制光电流光谱法（IMPS）和强度调制光电压光谱法（IMVS），根据电子扩散系数（D）和电子寿命（τ），研究了香豆素染料敏化纳米晶TiO₂电极中的电子传输动力学。我们发现，香豆素染料敏化TiO₂电极的τ值比涂有Ru配合物（N719染料）的电极的τ值短得多，这表明在香豆素染料敏化太阳能电池中，与TiO₂导带电子和电解质中I₃⁻离子之间复合相对应的背向电子转移过程更容易发生。此外，τ值取决于香豆素染料的种类，每种染料具有不同数量的噻吩部分，这表明吸附染料的分子结构也会影响TiO₂电极中的电子传输动力学。