A series of Ru(II) polypyridyl complexes were evaluated under electrochemically oxidative conditions, which generates the Ru(III) oxidation state and mimics the harsh conditions in dye-sensitized solar cells, to develop fundamental insights into the factors governing molecular sensitizer surface stability. Results revealed that minimizing time spent in the oxidized form, incorporating electron-donating groups, maximizing hydrophobicity, and minimizing molecular bulk near the adsorbed ligand are critical to optimizing the performance of Ru(II) polypyridyl complexes in dye-sensitized devices.
Raber, M. M.; Brady, M. D.; Troian-Gautier, L.; Dickenson, J. C.; Marquard, S. L.; Hyde, J. T.; Lopez, S. J.; Meyer, G. J.; Meyer, T. J.; Harrison, D. P. Fundamental Factors Impacting the Stability of Phosphonate-Derivatized Ruthenium Polypyridyl Sensitizers Adsorbed on Metal Oxide Surfaces. ACS Appl. Mater. Interfaces. 2018, 10 (26), 22821-22833. http://dx.doi.org/10.1021/acsami.8b04587