Incompletely Solvated Ionic Liquids as Electrolyte Solvents for Highly Stable Dye-Sensitized Solar Cells
(English)Article in journal (Other academic) Submitted
Ionic liquids have been intensively investigated as alternative stable electrolyte solvents for dye-sensitized solar cells (DSCs). A highest overall conversion efficiency of over 8% has been achieved using ionic-liquid-based electrolyte in combination with an iodide/triiodide redox couple. However, the relatively high viscosities of ionic liquids require higher iodine concentration in the electrolyte due to mass-transport limitations of the triiodide ions. The higher iodine concentration significantly reduces the photovoltaic performance, which normally are lower than those using organic solvent-based electrolytes. Here, the concept of incompletely solvated ionic liquids (ISILs) is introduced and represents a conceptually new type of electrolyte solvents for DSCs. It is found that the photovoltaic performance of ISIL-based electrolytes can rival that of organic solvent-based electrolytes. Furthermore, the vapor pressures of ISILs are found be considerably lower than that for pure organic solvent. Stability tests show that ISIL-based electrolytes provide highly stable DSCs under light-soaking conditions. Thus, ISIL-based electrolytes offer a new platform to develop more efficient and stable DSC devices of relevance to future large-scale applications.
IdentifiersURN: urn:nbn:se:kth:diva-63821OAI: oai:DiVA.org:kth-63821DiVA: diva2:482735
QS 201203282012-01-242012-01-242016-08-16Bibliographically approved