Insights into Ionic Liquid Electrolyte and Redox Mediator Design for Dye Sensitized Solar Cells

Wednesday, 12 October 2022: 10:00
Room 303 (The Hilton Atlanta)
A. V. Mudring (Aarhus Universitet)
We are currently living in an energy crisis. It has been realized that not only our energy consumption is rising and that we have to be aware to reduce our carbon footprint in order to mitigate climate change, but we are also seeing that carbon-based energy sources become critical resources, like critical raw materials, when they come for region of political instability. For all these reasons, it is important to advance energy harvesting from benign resources, such as sun light. It is assumed that harvesting the solar energy reaching the earth at 10 % efficiency would be enough to cover the current global electricity consumption. In this context, dye sensitized solar cells (DSSCs) are interesting. They are not only promising low-cost alternatives to semi-conductor solar cells, but they bear additional properties, such as being able to absorb diffused light, flexibility and transparence, which allows them to be used in many different application, consumer electronics being a very relevant market. Particularly interesting for the low cost segment of solar cells would be if they could be made in air and not necessarily would require a strict encapsulation of the components. In this context, we have investigated a series of DSSCs with triazolium halides as the electrolyte. Interestingly, they DSSCs surpassed the performance of those with analogous imidazolium compounds and even had higher lifetimes. A particular advantage over imidazolium salts is, that the triazolium analogues are not hygroscopic, which makes device fabrication easier and also leads to a significantly long-term stability of the devices. In addition, electrode passivation which is commonly observed with imidazolium iodides could not be noticed for the triazolium analogues. This renders triazolium ionic liquids interesting candidates for electrochemical applications, not only for DSSCs.