Highly Electrocatalytic Cu2ZnSn(S1鈥?i>xSex)4 Counter Electrodes for Quantum-Dot-Sensitized Solar Cells

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• 作者：Yuebin Cao ; Yanjun Xiao ; Jin-Young Jung ; Han-Don Um ; Sang-Won Jee ; Hye Mi Choi ; Jin Ho Bang ; Jung-Ho Lee
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：February 13, 2013
• 年：2013
• 卷：5
• 期：3
• 页码：479-484
• 全文大小：343K
• 年卷期：v.5,no.3(February 13, 2013)
• ISSN：1944-8252

文摘

Traditional Pt counter electrode in quantum-dot-sensitized solar cells suffers from a low electrocatalytic activity and instability due to irreversible surface adsorption of sulfur species incurred while regenerating polysulfide (S_n2鈥?/sup>/S2鈥?/sup>) electrolytes. To overcome such constraints, chemically synthesized Cu₂ZnSn(S_1鈥?i>xSe_x)₄ nanocrystals were evaluated as an alternative to Pt. The resulting chalcogenides exhibited remarkable electrocatalytic activities for reduction of polysulfide (S_n^2-) to sulfide (S2鈥?/sup>), which were dictated by the ratios of S/Se. In this study, a quantum dot sensitized solar cell constructed with Cu₂ZnSn(S_0.5Se_0.5)₄ as a counter electrode showed the highest energy conversion efficiency of 3.01%, which was even higher than that using Pt (1.24%). The compositional variations in between Cu₂ZnSnS₄ (x = 0) and Cu₂ZnSnSe₄ (x = 1) revealed that the solar cell performances were closely related to a difference in electrocatalytic activities for polysulfide reduction governed by the S/Se ratios.

Keywords:

quantum-dot-sensitized solar cells; copper zinc tin sulfur (selenium); counter electrodes; electrocatalytic activity