Abstract: Analyzing Dye-Sensitized Solar Cells Using Single Molecule Spectroscopy

The need for renewable energy sources is a continually growing concern, as fossil fuels are unsustainable and detrimental to the environment. Solar energy offers a cleaner alternative, and can be harnessed using dye-sensitized solar cells, DSSCs. Although these DSSCs are currently inefficient compared to solar cells primarily used, efforts can be placed in order to make these cells more efficient. Research in the Wustholz lab has focused on understanding electron transfer (ET) dynamics in DSSCs, in order to inform production and manufacturing of these cells, and make them more efficient. By focusing on single molecules, through single molecule spectroscopy, ET dynamics can be more thoroughly understood, without the interference of spatial and heterogeneous variances within these kinetics.

Previously studied DSSCs included rhodamine 560 dye, (R560), which was analyzed using a 470nm wavelength laser, and its blinking traces of emissive “on times” and nonemissive “off times” were taken. It was then found that these blinking traces had a different statistical fit, compared to  rhodamine dyes such as RB. The possibility arises that the differences in statistical distributions of on and off times between RB and R560 can be due to differences  in dye structure, or it was because the R560 was analyzed at 470nm rather than 532nm wavelength laser which the RB dyes were using. My research in the Wustholz lab this summer, will then study R560 using a 532nm laser the RB dye and test whether the different blinking behavior is an outcome of differences in dye structure, or laser wavelength. By exploring this behavior, a step forward will be made in further understanding the ET dynamics of DSSCs, which will also help in increasing efficiency of these DSSCs, making solar energy more viable.