The most common structure of a quantum dot-sensitized solar cell (QDSC) employs a metal sulfide counter electrode (CE) combined with a polysulfide electrolyte (S²⁻/S_n²⁻). Polyiodide electrolytes (I⁻/I₃⁻) have an advantage over polysulfide because of their high photovoltage output. However, most semiconductor QDs will dissolve in polyiodide. This work presents a new double-layer CE material Pt/CuSe that is compatible with polyiodide. The electrocatalytic activity of three types of CEs: Pt, CuSe and Pt/CuSe, are compared using cyclic voltammetry, Tafel plots and electrochemical impedance spectroscopy. Among the three CEs, the Pt/CuSe CE exhibits the best catalytic activity with low charge transfer resistance and a high current density. Pt/CuSe CEs are then applied in ternary Pb₅Sb₈S₁₇ QDSCs that are stable in polyiodide. The QDSC with the Pt/CuSe CE exhibits a power conversion efficiency (PCE) of 3.71% (with ZnS passivation), which is significantly higher than those of cells with Pt (2.53%) and CuSe (2.68%) CEs. At the reduced intensity of 0.1 sun, the PCE further increases to 5.54%, a respectable efficiency for a QDSC. To the best of our knowledge, Pt/CuSe is the first CE for QDSCs using polyiodide and has the potential for improving performance in QDSCs.

中文翻译：

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Pt / CuSe：一种用于量子点敏化太阳能电池中多碘化物还原的新型对电极

量子点敏化太阳能电池（QDSC）的最常见结构是将金属硫化物对电极（CE）与多硫化物电解质（S ^2- / S _n ^2-）结合使用。多碘化物电解质（I ^- / I ₃ ^-）由于具有高光电压输出，因此具有优于多硫化物的优势。但是，大多数半导体QD将溶解在聚碘化物中。这项工作提出了一种与聚碘兼容的新型双层CE材料Pt / CuSe。使用循环伏安法，Tafel图和电化学阻抗谱比较了三种类型的CEs（Pt，CuSe和Pt / CuSe）的电催化活性。在三种CE中，Pt / CuSe CE表现出最佳的催化活性，且电荷转移电阻低，电流密度高。然后将Pt / CuSe CEs应用于三元Pb ₅ Sb ₈ S ₁₇在聚碘中稳定的QDSC。具有Pt / CuSe CE的QDSC的功率转换效率（PCE）为3.71％（ZnS钝化），显着高于具有Pt（2.53％）和CuSe（2.68％）CE的电池。在降低的0.1太阳强度下，PCE进一步增加到5.54％，这对于QDSC来说是相当可观的效率。据我们所知，Pt / CuSe是使用聚碘化物的QDSC的首个CE，具有改善QDSC性能的潜力。