The role of transition metal complexes in dye sensitized solar devices

This article focuses on the progress obtained in the design of metal complexes which find application as sensitizers for dye-sensitized solar cells, DSSCs, and as electron shuttles in substitution of the triiodide/iodide redox couple. Coupling of sterically hindered dyes with mobile shuttles, based on a transition metal complex, represents the most advanced innovation which has allowed to reach on a single device the record efficiency of 12%. Issues which require further research are also discussed.