PHYS 383 |
| Knowledge of dye orientation on a semiconductor surface is imperative to the full understanding of the mechanism of interfacial electron transfer, dye-sensitized solar cells, and molecular electronics. Second harmonic generation (SHG) and sum frequency generation (SFG) spectroscopy have been recognized as important tools for determining the average orientation of a molecular monolayer at an interface due to their interface specificity and monolayer sensitivity. We have used these methods to investigate the average orientation of four dye molecules on thin TiO2 films: coumarin 343 (C343), rhodamine 6G (Rh6G), Re(Lp)(CO)3Cl (ReC0A) [Lp= 2,2'-bipyridine-4,4'-bis-COOH], and Re(Lp)(CO)3Cl (ReC1P) [Lp= 2,2'-bipyridine-4,4'-bis-CH2-PO3H2]. The polarization dependent SHG and/or SFG signal was recorded at select resonant wavelengths for each dye. Analysis of the ratio of spectra collected at different polarizations can be used to determine the average dye orientation. We will present our results of this ongoing study of the orientation of dyes on TiO2 films. |
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PHYS Poster Session - General Experiment
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Physical Chemistry |