Comparing Electron Recombination via Interfacial Modifications in Dye-Sensitized Solar Cells

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• 作者：Luping Li ; Shikai Chen ; Cheng Xu ; Yang Zhao ; Nicholas G. Rudawski ; Kirk J. Ziegler
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：December 10, 2014
• 年：2014
• 卷：6
• 期：23
• 页码：20978-20984
• 全文大小：374K
• ISSN：1944-8252

文摘

Establishing a blocking layer between the interfaces of the photoanode is an effective approach to improve the performance of dye-sensitized solar cells (DSSCs). In this work, HfO₂ blocking layers are deposited via atomic layer deposition (ALD) onto tin-doped indium oxide (ITO) and TiO₂. In both cases, addition of the blocking layer increases cell efficiencies to greater than 7%. The improved performance for a HfO₂ layer inserted between the ITO/TiO₂ interface is associated with an energy barrier that reduces electron recombination. HfO₂ blocking layers between the TiO₂/dye interface show more complex behavior and are more sensitive to the number of ALD cycles. For thin blocking layers on TiO₂, the improved device performance is attributed to the passivation of surface states in TiO₂. A distinct transition in dark current and electron lifetime are observed after 4 ALD cycles. These changes to performance indicate thick HfO₂ layers on TiO₂ formed an energy barrier that significantly hinders cell performance.

Keywords:

dye-sensitized solar cell; blocking layer; trap states; atomic layer deposition; electron recombination