Synthesis of carborane cluster containing macrocycles for use in dye-sensitized solar cells

Dye-sensitized solar cell (DSSC) efficiencies have not significantly improved in recent years, primarily because of their single band gap design, limitations in dye absorption energies, and the Shockley-Queisser (SQ) limit. DSSCs require an incident energy in the visible spectrum for the cell to produce a useable electrical current. While the possibility of absorbing two near-infrared photons is a known concept for surmounting the SQ limit, the opportunities presented by mesoporous systems for creating such a sensitizer do not appear to have been studied. By incorporating carborane cluster-based macrocyclic compounds as "electron reservoirs," a number of the inherent limitations in DSSC systems can be potentially circumvented, including extending the useable photon energy into the IR region by using a multi-photon, multi-step mechanism. Thus, effectively surmounting the SQ limit. In this paper, our work towards the synthesis of this prototype carborane macrocyclic system will be presented in detail.