Laboratoire de Photonique et Interfaces, Institut des Sciences et Ingénieurie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland.
J Am Chem Soc. 2011 Jun 22;133(24):9304-10. doi: 10.1021/ja110541t. Epub 2011 May 25.
Employing a mesoscopic titania photoanode whose bilayer structure was judiciously selected to fit the optoelectronic characteristics of the Ru-based heteroleptic complex Na-cis-Ru(4,4'-(5-hexyltiophen-2-yl)-2,2'-bipyridine)(4-carboxylic-acid-4'-carboxylate-2,2'-bipyridine)(thiocyanate)(2), coded as C101, we investigated the effect of temperature for dye adsorption on the photovoltaic performance of dye-sensitized solar cells (DSCs). We found a significant efficiency enhancement upon lowering the temperature applied during the sensitizer uptake from solution. When the dye adsorption was performed at 4 °C, the photovoltaic performance parameters measured under standard reporting conditions (AM1.5 G sunlight at 1000 W/m(2) intensity and 25 °C), i.e., the open circuit voltage (V(oc)), the short circuit photocurrent density (J(sc)), the fill factor (FF), and consequently the power conversion efficiency (PCE), improved in comparison to cells stained at 20 and 60 °C. Results from electrochemical impedance spectroscopy (EIS) and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) show that the self-assembled layer of C101 formed at lower temperature impairs the back-electron transfer from the TiO(2) conduction band to the triiodide ions in the electrolyte more strongly than the film produced at 60 °C. Profiting from the favorable influence that the low-temperature dye uptake exerts on photovoltaic performance, we have realized DSCs showing a power conversion efficiency of 11.5%.
采用介观二氧化钛光阳极，其双层结构经过精心选择，以适应基于 Ru 的杂配配合物 Na-cis-Ru(4,4'-(5-己基噻吩-2-基)-2,2'-联吡啶)(4-羧酸-4'-羧酸酯-2,2'-联吡啶)(硫氰酸根)(2)的光电特性。我们研究了温度对染料吸附对染料敏化太阳能电池 (DSC) 光伏性能的影响。我们发现，在从溶液中摄取敏化剂时降低温度会显著提高效率。当在 4°C 下进行染料吸附时，在标准报告条件下（在 1000 W/m(2)强度和 25°C 的 AM1.5G 阳光下）测量的光伏性能参数，即开路电压 (V(oc))、短路光电流密度 (J(sc))、填充因子 (FF)，以及由此产生的功率转换效率 (PCE)，与在 20 和 60°C 下染色的电池相比有所提高。电化学阻抗谱 (EIS) 和衰减全反射傅里叶变换红外光谱 (ATR-FTIR) 的结果表明，在较低温度下形成的 C101 自组装层比在 60°C 下形成的薄膜更强烈地阻碍 TiO(2)导带中的电子向后向三碘化物离子转移。从低温染料摄取对光伏性能的有利影响中受益，我们已经实现了功率转换效率为 11.5%的 DSC。
