Photoelectrochemical kinetics of Eosin Y-sensitized zinc oxide films investigated by scanning electrochemical microscopy under illumination with different LED
Photoelectrochemical kinetics of Eosin Y-sensitized zinc oxide films investigated by scanning electrochemical microscopy under illumination with different LED
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DOI：
10.1016/j.electacta.2009.08.062
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发表时间：
2009-12
影响因子：
6.6
通讯作者：
Yan-Fei Shen;U. Tefashe;K. Nonomura;T. Loewenstein;D. Schlettwein;G. Wittstock
中科院分区：
文献类型：
--
作者：
Yan-Fei Shen;U. Tefashe;K. Nonomura;T. Loewenstein;D. Schlettwein;G. Wittstock
染料敏化太阳能电池中光诱导电荷分离的总体效率取决于氧化还原电解质的反电子转移和染料再生过程之间的动力学竞争。在之前的研究中，利用扫描电化学显微镜（SECM）的反馈模式，研究了碘离子在电解质相中对间歇形成的光氧化染料分子的还原，并推导了定量模型。本文通过对激发波长、光强和介质浓度的变化，对该模型进行了更彻底的实验验证。采用自组装法制备的纳米多孔ZnO/Eosin Y薄膜作为模型电极，并与碘/三碘电解质一起使用。实验发现，有效速率常数与溶解供体与氧化后的伊红Y结合ZnO的反应速率常数和染料的吸收光谱有关，并证实了模型推导中的假设。对于伊红Y的再生过程，确定了不同发光二极管和光照强度下的kox速率常数。
The overall efficiency of the light-induced charge separation in dye-sensitized solar cells depends on the kinetic competition between back electron transfer and dye regeneration processes by a redox electrolyte. In a previous study, the reduction of the intermittently formed photo-oxidized dye molecules by iodide ions in the electrolyte phase was investigated using the feedback mode of a scanning electrochemical microscope (SECM) and a quantitative model had been derived. Here we provide a more thorough experimental verification of this model by variation of the excitation wavelength, light intensities and mediator concentrations. Nanoporous ZnO/Eosin Y films prepared by self-assembly were used as model electrodes and were used with an iodide/triiodide electrolyte. The experimentally found effective rate constants could be related to the rate constant for the reaction of the dissolved donor with photo-oxidized Eosin Y bound to ZnO and the absorption spectrum of the dye and confirmed the assumption made in the derivation of the model. For the regeneration process of Eosin Y, a rate constant of koxwith different light emitting diodes and light intensities is determined.