Proceedings of International Conference on Hybrid and Organic Photovoltaics 2015 (HOPV15)
Publication date: 5th February 2015
The electron transfer chemistry of halides are intimately coupled to the formation and breaking of halogen-halogen bonds (1). This chemistry has been exploited for solar energy conversion in regenerative dye-sensitized solar cells and are relevant to perovskite solar cells, yet many of the intimate mechanistic details remain poorly understood. In this presentation fundamental studies of halide redox chemistry in fluid solution and at solid-state interfaces will be presented and analyzed with existing theories. Evidence for inner-sphere electron transfer reaction mechanisms have been garnered through systematic studies of iodide oxidation by ruthenium polypyridyl compounds. A dramatic shift in the one-electron transfer reduction potential of tri-iodide relative to the two-electron transfer potential was discovered that underlies the amazing success of iodide redox mediators in dye-sensitized solar cells. Studied of ligand-to-metal charge transfer (LMCT) reactivity in metal halide complexes relevant to perovskite solar cells will also be presented. LMCT light excitation generates iodine atoms and di-iodide that undergo subsequent redox chemistry with the reduced metal center. The details of these studies will be summarized.
1) Rowley, J.G.; Farnum, B.H.; Ardo, S.; Meyer, G.J.Iodide Chemistry in Dye-Sensitized Solar Cells: Making and Breaking I-I Bonds for Solar Energy Conversion. J. Phys. Chem. Lett. 2010, 1, 3132 - 3140.