Use of ionic liquids in dye-sensitised solar cells

Dye-sensitised solar cells (DSSCs) are increasingly being recognised as a viable alternative to conventional silicon-based solar cells; these devices have significant potential advantages in terms of material costs and toxicity, as well as the potential to manufacture ultra-thin and flexible cells. One of the key components of an efficient and stable DSSC is the electrolyte, and while ethanenitrile-based electrolytes currently provide the best efficiencies, the use of ionic liquids is extremely beneficial in terms of device stability. This chapter discusses the different aspects of research into the use of ionic liquids in DSSCs. A range of different anions and cations have been utilised in combination with a wide variety of different photosensitisers, including a number of organic dyes. The development of quasi-solid state electrolytes that utilise ionic liquids is a very promising area of research, while the development of ionic liquid-based devices with different redox couples is very important, but has thus far had only limited success. The use of alternative counter electrodes and different cell structures, in combination with ionic liquids, is also discussed.