Earth Abundant Silicon Composites as the Electrocatalytic Counter Electrodes for Dye-Sensitized Solar Cells

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• 作者：Chun-Ting Li ; Yu-Lin Tsai ; Kuo-Chuan Ho
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：March 23, 2016
• 年：2016
• 卷：8
• 期：11
• 页码：7037-7046
• 全文大小：634K
• ISSN：1944-8252

文摘

Earth abundant silicon compounds, including Si₃N₄, SiO₂, SiS₂, and SiSe₂, were introduced as the electrocatalytic materials for the counter electrodes (CE) in dye-sensitized solar cells (DSSCs). Among these silicon-based materials, Si₃N₄, SiS₂, and SiSe₂ were applied in DSSCs for the first time. In the presence of a conducting binder, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), various silicon-based composites (Si₃N₄/PEDOT:PSS, SiO₂/PEDOT:PSS, SiS₂/PEDOT:PSS, and SiSe₂/PEDOT:PSS) were successfully coated on the ITO substrates via a simple drop-coating process. In a composite film, silicon-based nanoparticles provided attractive electrocatalytic ability and plenty of electrocatalytic active sites for the triiodine ion (I₃^–) reduction. PEDOT:PSS not only acted as a good conducting binder for silicon-based nanoparticles, but also provided a continuous polymer matrix to increase the electron transfer pathways. By adjusting the weight percent (1–5 wt %) of the silicon-based nanoparticles (Si₃N₄, SiO₂, SiS₂, and SiSe₂) with respect to the weight of PEDOT:PSS, the composite films containing 5 wt % Si₃N₄ (denoted as Si₃N₄-5) and 5 wt % SiSe₂ (denoted as SiSe₂-5) both reached excellent electrocatalytic abilities and rendered the good cell efficiencies (η) of 8.2% to their DSSCs. It can be said that both Si₃N₄-5 and SiSe₂-5 are promising electrocatalytic materials to replace the rare and expensive Pt (η = 8.5%).