Bella F, Galliano S, Falco M, Viscardi G, Barolo C, Grätzel M, Gerbaldi C
GAME Lab , CHENERGY Group , Department of Applied Science and Technology - DISAT , Politecnico di Torino , Corso Duca degli Abruzzi 24 , 10129-Torino , Italy . Email:
Department of Chemistry and NIS Interdepartmental Centre , Università degli Studi di Torino , Via Pietro Giuria 7 , 10125-Torino , Italy . Email:
Chem Sci. 2016 Aug 1;7(8):4880-4890. doi: 10.1039/c6sc01145d. Epub 2016 Apr 13.
Aqueous dye-sensitized solar cells (DSSCs) have recently emerged as promising systems, which can combine low cost and environmental compatibility with appreciable efficiency, long-term durability and enhanced safety. In the present study, we thoroughly investigate the chemistry behind the iodide/triiodide-based redox mediator, which presents - in a completely aqueous environment - several differences when compared to the behavior observed in the conventionally used organic solvents. The speciation of ions, the effect of the concentration of the redox mediator and the type of counter-ion are characterized from the electrochemical, spectroscopic, photovoltaic and analytical viewpoints. Furthermore, we demonstrate that aqueous DSSCs, often assumed as unstable, hold the potential to assure unparalleled stability after five months of aging without any addition of stabilizers or gelling agents, thus envisaging the construction of eco-friendly photovoltaic devices free of expensive, flammable and toxic solvents.
水系染料敏化太阳能电池（DSSC）最近已成为很有前景的系统，它可以将低成本和环境兼容性与可观的效率、长期耐久性及更高的安全性结合起来。在本研究中，我们深入探究了基于碘化物/三碘化物的氧化还原介质背后的化学原理，该介质在完全水性的环境中与在传统使用的有机溶剂中观察到的行为相比存在若干差异。从电化学、光谱学、光伏和分析的角度对离子的形态、氧化还原介质浓度的影响以及抗衡离子的类型进行了表征。此外，我们证明了通常被认为不稳定的水系DSSC在不添加任何稳定剂或胶凝剂的情况下老化五个月后仍有潜力确保无与伦比的稳定性，从而设想构建不含昂贵、易燃和有毒溶剂的环保型光伏器件。
