高活性硫化铅电极的制备及在量子点敏化太阳能电池中的应用

为了提高量子点敏化纳晶薄膜太阳能电池的光电转换效率,我们通过连续在酸和多硫溶液中处理铅片制备了对多硫电解液具有高电催化活性的硫化铅电极.通过电化学阻抗谱测试评价所制备硫化铅电极的催化活性,从而确定制备高效硫化铅电极的最佳条件.以在最佳条件下制备的硫化铅为对电极、CdSe量子点敏化TiO2纳晶薄膜为工作电极和多硫电解液组装成量子点敏化太阳能电池.光电性能测试结果表明所制备的电极具有良好的催化活性和光电转换性能.与已报导的方法相比,新方法大幅度地减少制备过程所需的时间,但却提高了所制备的硫化铅对电极的催化活性.通过X射线衍射和扫描电镜测试表征了硫化铅的生成过程,探讨了催化活性提高的原因.

Preparation of a Highly Efficient PbS Electrode and Its Application in Quantum Dots-Sensitized Solar Cells

To improve the light-to-electric conversion efficiency of quantum dots-sensitized nanocrystalline thin-film solar cells, a PbS electrode with high electrocatalytic activity toward polysulfide electrolyte was prepared by successively treating Pb foil in acid and polysulfide solutions. Electrochemical impedance spectroscopy (EIS) measurements were performed to evaluate the electrocatalytic activity of the prepared PbS electrode. Based on the EIS results, the temperature and time to treat the Pb foil in the acid solution were optimized. The PbS electrode prepared under the optimized conditions was used as a counter electrode to fabricate a quantumdotssensitized solar cell with a CdSe quantum dots-sensitized TiO₂ nanocrystalline thin film as the photoanode and polysulfide solution as the electrolyte. Both the electrocatalytic activity and light-to-electric conversion properties of the PbS electrode prepared from acid treatment of Pb foil for the optimized temperature and time are superior to those of electrodes prepared by other reported methods. In our method, the treatment time is considerably less but the PbS counter electrode maintains a superior catalytic activity compared with other methods. X-ray diffraction and scanning electron microscopy were performed to demonstrate the formation process of PbS, and the catalytic enhancement mechanism of the prepared PbS electrode is discussed.