There is much interest in energy sources other than fossil fuels to power today's world. Solar cell research is among some of the promising venues of exploration in energy research. Ruthenium (II) complexes are finding applications in a variety of fields, in particular, as photo-sensitizers in the conversion of solar energy into chemical or electrical energy [1]. They are of great interest due to their photochemical and photoelectrical properties as photo sensitizers in dye sensitized solar cells (DSSC). Efforts to increase device cell efficiencies of DSSCs include varying anchoring groups,[1] structural modification of ancillary ligands of well known photosensitizers,[2] increasing the excited-state lifetime, decreasing the bandgap, and increasing the range of absorbed wavelengths[3,4]. In such a case, this emission lifetime data becomes important in understanding the potential increase in efficiency of a solar cell. These lifetime measurements require a specific setup involving Nd:YAG, photomultiplier tube (PMT), oscilloscope and a computer. Due to their effect on solar cell efficiency lifetime, plots obtained from this setup are of vital importance in the studies of DSSCs. In this study seven different substituted complexes of [Ru(bpy)₃]⁺² were analyzed and their lifetimes were obtained. Based on a surprisingly long lifetime of 4,4'-bis(4-methoxy-phenylethynyl)-2,2'-bipyridine, a temperature and solvent study was also conducted.

References: 1. Andre Sarto Polo, Melina Kayoko Itokazu, Neyde Yokie Murakami Iha. Coordination Chemistry Reviews 2005, 248, 1343-1361 2. Weng, Y.-X.; Li, L.; Liu, Y.; Wang, L.; Yang, G.-Z. J. Phys Chem B 2003, 107, 4356 3. Saito, Y Azechi, T; Kitamura, T; Hasegawa, Y; Wada, Y; Yanagida, S. Coordination Chemistry Reviews 2004, 248, 1469-1478 4. Nogueira, A.F; Longo, C; De Paoli, M.A. Coordination Chemistry Reviews 2005, 248 1455-1468.