Resonance Raman Spectroscopy of Dyes Used as Solar Energy Sensitizers
EMSL Project ID
2437
Abstract
Resonance Raman spectroscopy (RRS) will be used to probe the structure and excited state dynamics of dyes employed in dye-sensitized solar energy cells based on titanium dioxide. Two classes of dyes will be explored: ruthenium(II)trisbipyridine (Rubpy) and tetracarboxyphenylporphyrin. (TCPP). The electronic structure of Rubpy remains poorly understood, in spite of years of research, due to the possible complication of overlapping electronic transitions in the visible spectrum. In addition, the excited state relaxation in water has been found in our lab to be dependent on solvent isotope. RRS will help to determine the nature of the visible transition and the basis for the solvent isotope effect. The TCPP dyes display a rich variety of visible spectra as a result of aggregation in aqueous solution. Unlike the more widely studied sulfonato-substituted porphyrin (TSPP), which also aggregates in water, TCPP aggregates have spectra which depend strongly on the presence of counter ions (nitrate, sulfate, chloride, etc.). RRS spectra excited at wavelengths within the monomer and aggregate absorption bands will help us to understand the structure of the aggregates, which form only in water solution. We propose to collaborate with Dr. Zheming Wang to pursue these questions by making Resonance Raman measurements at a number of blue excitation wavelengths. The experiments will be attempted using the tunable MOPO available in Dr. Wang's lab as a source, and a suitable array detector such as the Princeton Instruments ICDD. We hope that the proposed experiments will lead to further collaboration with EMSL scientists on projects of mutual interest.
Project Details
Project type
Exploratory Research
Start Date
2002-02-01
End Date
2003-01-13
Status
Closed
Released Data Link
Team
Principal Investigator