Fabrication of Dye-Sensitized Solar Cells by Using Self-Assembled Electrodeposition

我们在0.1M ZnNO_3溶液或0.1M KCl+5mM ZnCl_2 o_2泡浴中，用浓度为10-50μM的各种染料对衬底进行阴极处理，成功地沉积了纳米多孔ZnO/染料杂化膜。在-1.0V （vs.SCE）下从含有伊红染料的浴液中沉积的薄膜由海绵状单晶组成，其上吸附着伊红分子。通过旋转圆盘电极，我们分析了ZnO/染料杂化膜的动力学，得出了具有这种独特微观结构的薄膜是在阴极化的eosin、Zn^<2+>离子和溶解氧的相互作用下以自组装的方式生长的。将得到的ZnO/eosinY薄膜浸入稀释的碱性溶液中，eosinY分子被解吸，而不会引起ZnO晶体的任何变化。利用这些纳米多孔ZnO薄膜作为模板材料，我们成功地将其浸入染料溶液中，得到了各种染料修饰的ZnO薄膜。通过解吸和再吸附得到的以伊红或香豆素343染料修饰的薄膜具有非常高的入射光子和电流转换效率，约为90%。由于这些工艺在低于100℃的温度下进行，因此适用于导电塑料基板。这些结果有望实现薄膜型彩色太阳能电池。

We have succeeded to deposit nano-porous ZnO/dye hybrid films by cathodizing a substrate in 0.1M ZnNO_3 solution or O_2-bublled 0.1M KCl+5mM ZnCl_2 bath containing various dyes with concentration of 10-50μM. The films deposited at -1.0V (vs.SCE) from baths containing eosinY dye have been found to be composed of sponge-like single crystals, on which eosinY molecules are adsorbed. By using a rotating disk electrode, we have analyzed kinetics of the ZnO/dye hybrid films and concluded that the films with such a unique microstructure are formed under the interaction of cathodized eosinY, Zn^<2+> ion and dissolved oxygen in the self-assembled growth manner. Dipping ZnO/eosinY films thus obtained into a diluted alkaline solution, eosinY molecules are desorbed without causing any change in ZnO crystals. By utilizing these nano-porous ZnO films as template materials, we have succeeded to get ZnO films modified with various dyes by dipping into those dye solutions. The films modified with eosinY or coumarine343 dyes thus obtained by the desorption followed by the re-adsorption exhibit very high incident photon to current conversion efficiencies around 90%. As these processes are carried out at temperatures lower than 100℃, this is applicable to a conductive plastic substrate. These results promise a realization of the film-type colorful solar cells.