Role of One-Dimensional Ribbonlike Nanostructures in Dye-Sensitized TiO2-Based Solar Cells

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• 作者：Jiazang Chen ; Bo Li ; Jianfeng Zheng ; Suping Jia ; Jianghong Zhao ; Huanwang Jing ; Zhenping Zhu
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：April 14, 2011
• 年：2011
• 卷：115
• 期：14
• 页码：7104-7113
• 全文大小：1061K
• 年卷期：v.115,no.14(April 14, 2011)
• ISSN：1932-7455

文摘

In dye-sensitized solar cells, there is a competition between transport of electrons through the porous semiconductor electrode toward the conducting substrate and back-reaction of electrons to recombination with I₃^{鈭?/sup> ions on the semiconductor鈭抏lectrolyte interface, which determines the charge collection efficiency and is strongly influenced by the electronic site distribution in intraband and geometrical structure of the semiconductors. Herein, we systematically analyze the electrochemical parameters of TiO₂ nanoribbon- and nanoparticle-based electrodes by electrochemical impedance spectroscopy. The results show that the intrinsic one-dimensional crystalline structure of TiO₂ nanoribbons can promote formation of a space charge layer on the surface of the semiconductor, which effectively blocks the recombination of electrons with I₃鈭?/sup> ions in the semiconductor鈭抏lectrolyte interface, resulting in an increase of electron lifetime and a higher cell voltage. Furthermore, the boundaryless structure of the TiO₂ nanoribbons provides efficient channels for electron transport and therefore increases electron diffusion length. The combination of TiO₂ nanoparticle-based electrode with TiO₂ nanoribbons can significantly improve energy conversion efficiency of 60%. These data provide a basic understanding of the role of TiO₂ geometrical structure in solar energy conversion.}