Dye mediated charge recombination dynamics in nanocrystalline TiO2 dye sensitized solar cells

Dye-electrolyte interactions play an important role in mediating the recombination between injected electrons in the TiO₂ electrode and the iodide/tri-iodide red-ox electrolyte in Dye Sensitized Solar Cells. This reaction reduces both cell voltage and efficiency and controlling it is therefore key to optimization and stability of such devices. This highlight will focus on experimental methods developed to monitor these recombination processes in functioning cell devices. Moreover, we discuss how certain dye structures seem to greatly accelerate recombination, in particular, in the case of highly conjugated sensitizers. Greater understanding of dye-interactions and ways to minimize them will help in the design of new sensitizers that show negligible recombination ultimately leading to optimization of cell efficiency.