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

我们在0.1M的氧化锌溶液或含10-50μM各种染料的0.1M充氧0.1MKCl+5 mMZCl2溶液中阴极沉积了纳米多孔氧化锌/染料杂化薄膜。从含有曙红Y染料的镀液中沉积的薄膜由海绵状单晶组成，曙红Y分子吸附在其上。利用旋转圆盘电极对氧化锌/染料杂化薄膜的动力学进行了分析，认为这种独特的微结构是在阴极曙红Y、锌离子和溶解氧以自组装方式生长的情况下形成的。将这样得到的氧化锌/曙红Y薄膜浸泡在稀碱性溶液中，曙红Y分子被解吸，而不会引起氧化锌晶体的任何变化。利用这些纳米多孔氧化锌薄膜作为模板材料，通过浸渍这些染料溶液，我们成功地得到了不同染料修饰的氧化锌薄膜。用曙红Y或香豆素343染料修饰的薄膜，通过解吸和再吸附得到的薄膜表现出很高的入射光-电流转换效率，约为90%。由于这些工艺是在低于100℃的温度下进行的，因此适用于导电塑料基板。这些结果预示着薄膜型彩色太阳能电池的实现。

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.