Apostolopoulou Andigoni, Vlasiou Manolis, Tziouris Petros A, Tsiafoulis Constantinos, Tsipis Athanassios C, Rehder Dieter, Kabanos Themistoklis A, Keramidas Anastasios D, Stathatos Elias
†Nanotechnology and Advanced Materials Laboratory, Electrical Engineering Department, Technological-Educational Institute of Western Greece, GR-26334 Patras, Greece.
∥Department of Physics, University of Patras, GR-26500 Patras, Greece.
Inorg Chem. 2015 Apr 20;54(8):3979-88. doi: 10.1021/acs.inorgchem.5b00159. Epub 2015 Apr 6.
Corrosiveness is one of the main drawbacks of using the iodide/triiodide redox couple in dye-sensitized solar cells (DSSCs). Alternative redox couples including transition metal complexes have been investigated where surprisingly high efficiencies for the conversion of solar to electrical energy have been achieved. In this paper, we examined the development of a DSSC using an electrolyte based on square pyramidal oxidovanadium(IV/V) complexes. The oxidovanadium(IV) complex (Ph4P)2[V(IV)O(hybeb)] was combined with its oxidized analogue (Ph4P)[V(V)O(hybeb)] {where hybeb(4-) is the tetradentate diamidodiphenolate ligand [1-(2-hydroxybenzamido)-2-(2-pyridinecarboxamido)benzenato}and applied as a redox couple in the electrolyte of DSSCs. The complexes exhibit large electron exchange and transfer rates, which are evident from electron paramagnetic resonance spectroscopy and electrochemistry, rendering the oxidovanadium(IV/V) compounds suitable for redox mediators in DSSCs. The very large self-exchange rate constant offered an insight into the mechanism of the exchange reaction most likely mediated through an outer-sphere exchange mechanism. The V(IV)O(hybeb)/V(V)O(hybeb) redox potential and the energy of highest occupied molecular orbital (HOMO) of the sensitizing dye N719 and the HOMO of V(IV)O(hybeb) were calculated by means of density functional theory electronic structure calculation methods. The complexes were applied as a new redox mediator in DSSCs, while the cell performance was studied in terms of the concentration of the reduced and oxidized form of the complexes. These studies were performed with the commercial Ru-based sensitizer N719 absorbed on a TiO2 semiconducting film in the DSSC. Maximum energy conversion efficiencies of 2% at simulated solar light (AM 1.5; 1000 W m(-2)) with an open circuit voltage of 660 mV, a short-circuit current of 5.2 mA cm(-2), and a fill factor of 0.58 were recorded without the presence of any additives in the electrolyte.
腐蚀性是在染料敏化太阳能电池（DSSC）中使用碘化物/三碘化物氧化还原对的主要缺点之一。包括过渡金属配合物在内的替代氧化还原对已被研究，在这些研究中令人惊讶地实现了太阳能到电能转换的高效率。在本文中，我们研究了一种基于正方锥氧化钒（IV/V）配合物的电解质的DSSC的开发。氧化钒（IV）配合物（Ph4P）2[V（IV）O（hybeb）]与其氧化类似物（Ph4P）[V（V）O（hybeb）] {其中hybeb（4-）是四齿二酰胺基二酚盐配体[1-（2-羟基苯甲酰胺基）-2-（2-吡啶甲酰胺基）苯并酸盐]}组合，并用作DSSC电解质中的氧化还原对。这些配合物表现出较大的电子交换和转移速率，这从电子顺磁共振光谱和电化学中可以明显看出，使得氧化钒（IV/V）化合物适用于DSSC中的氧化还原介质。非常大的自交换速率常数为最有可能通过外层球交换机制介导的交换反应的机制提供了深入了解。通过密度泛函理论电子结构计算方法计算了V（IV）O（hybeb）/V（V）O（hybeb）氧化还原电位以及敏化染料N719的最高占据分子轨道（HOMO）能量和V（IV）O（hybeb）的HOMO。这些配合物被用作DSSC中的新型氧化还原介质，同时根据配合物还原态和氧化态的浓度研究电池性能。这些研究是在DSSC中负载在TiO2半导体膜上的商用Ru基敏化剂N719上进行的。在模拟太阳光（AM 1.5；1000 W m(-2)）下，开路电压为660 mV，短路电流为5.2 mA cm(-2)，填充因子为0.58，在电解质中不存在任何添加剂的情况下，记录到最大能量转换效率为2%。
