Oekermann Torsten, Yoshida Tsukasa, Boeckler Cathrin, Caro Jürgen, Minoura Hideki
Institute of Physical Chemistry and Electrochemistry, University of Hannover, Callinstrasse 3-3A, 30167 Hannover, Germany.
J Phys Chem B. 2005 Jun 30;109(25):12560-6. doi: 10.1021/jp051394p.
Electrodeposited nanoporous ZnO/eosin Y hybrid films have been investigated in view of their potential applications in dye-sensitized solar cells and supercapacitors. Intensity-modulated photocurrent spectra were measured at different electrode potentials at films of different thicknesses. It was found that the results represent either the RC constant of the cell and surface recombination of photogenerated holes with electrons or the diffusion of photogenerated electrons and are dependent on the electron concentration in the ZnO, which is influenced by the film thickness, the electrode potential, and the light intensity. The results suggest that the porosity of the electrodeposited ZnO increases with the film thickness and the films therefore consist of two parts, a less porous part deposited in the first few minutes that exhibits field-driven electron transport and a more porous outer part where electron transport is by diffusion. The results are supported by frequency-dependent capacitance measurements, which also show that the material is suitable for supercapacitors.
鉴于电沉积纳米多孔ZnO/曙红Y混合薄膜在染料敏化太阳能电池和超级电容器中的潜在应用，对其进行了研究。在不同厚度薄膜的不同电极电位下测量了强度调制光电流光谱。结果表明，这些结果要么代表电池的RC常数以及光生空穴与电子的表面复合，要么代表光生电子的扩散，并且取决于ZnO中的电子浓度，而电子浓度受薄膜厚度、电极电位和光强度的影响。结果表明，电沉积ZnO的孔隙率随薄膜厚度增加，因此薄膜由两部分组成，前几分钟沉积的孔隙较少的部分表现出场驱动电子传输，而孔隙较多的外部部分电子传输是通过扩散进行的。频率相关电容测量结果支持了这些结果，该测量还表明该材料适用于超级电容器。
