NIR energy relay dyes are lightly co-sensitized (5-15% of the titania surface) with metal complex dyes (85-95% of titania surface) which produce world record efficiencies but that do not absorb light strongly in the near-infrared portion of the solar spectrum. Increased near-infrared light harvesting in a state-of-the-art dye-sensitized solar cell using energy transfer in a co-sensitized system. Building on earlier efforts this idea is much more subtle. Essentially the key is that the red-shifted dye is able to efficiently undergo energy transfer and be contribute to the photocurrent. This concept greatly reduces the design rules of the near-infrared dye which will allow this invention to be fully demonstrated quickly.
This invention makes it possible to increase the power conversion efficiency of record dye-sensitized solar cells from 11% to 13%. Low efficiency DSCs are currently be commercialized increasing the power conversion by >15% would greatly increase the market competitiveness of DSCs. It is also important to note that this technique may not require any additional processing steps and would result in a negligible cost.