First-Principles Investigation on Electronic Properties of Quantum Dot-Sensitized Solar Cells Based on Anatase TiO2 Nanotubes

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• 作者：Cunku Dong ; Xin Li ; Jingyao Qi
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：October 20, 2011
• 年：2011
• 卷：115
• 期：41
• 页码：20307-20315
• 全文大小：1162K
• 年卷期：v.115,no.41(October 20, 2011)
• ISSN：1932-7455

文摘

The first-principles quantum mechanical investigation on CdS quantum dots (QDs) adsorbed on anatase TiO₂ nanotubes (TiO₂NTs) in quantum dot-sensitized solar cells (QDSSCs) was performed using the density functional theory (DFT) approach. The geometry and electronic coupling between a CdS QD and the TiO₂NT have been examined for the first time, together with a detailed discussion of interfacial electron transfer and electron transport models along the TiO₂NT. It has been found that adsorbate states are introduced in the band gap of the TiO₂NT upon the adsorption of a CdS QD on the TiO₂NT surface, and an electron transfers from the sulfur atoms of a CdS QD to the conduction band of the TiO₂NT upon adsorption of visible light. The unique TiO₂NT structure offers a one-dimensional directional pathway for electron transport across the semiconductor substrate through titanium d_x²鈥搚² and d_z² orbitals. Our work is of great benefit for understanding the charge separation process at the heterogeneous interface and the key factors to govern the electron transport efficiency in TiO₂NTs.