POLY 497 |
| Molecular scale engineering of materials for organic electronics is highly appealing but requires nanoscopic characterization techniques to learn more about structure-property relationships. Recently, we combined two such powerful means – single molecule fluorescence spectroscopy and single molecule surface enhanced resonance Raman spectroscopy – to a simultaneous, low-temperature spectroscopic tool whose strength we demonstrated in revealing excited state relaxation mechanisms in conjugated polymers. By comparing the respective fluorescence and Raman fingerprint spectra and by correlating their temporal behaviors, we were able to track inter- and intrachromophoric excited state relaxation, namely excitation energy transfer and exciton self-trapping. These promising results encouraged abandoning the restrictions of low-temperature and resonant excitation, which were used in our earlier study. We report on single molecule Raman spectroscopy on the conjugated polymer poly(phenylene-ethynylene-butadiynylene) under ambient conditions and in a simple experimental setup. The 2200 cm-1 Raman band characteristic for the C-C triple bonds in this polymer allows unambiguous identification. The results draft a simple experimental route to performing SERS measurements on single π-conjugated polymer molecules which may enable the tracking of single charging events in devices in the future. |
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30 Years of Conducting Polymers
8:30 AM-12:35 PM, Wednesday, March 28, 2007 McCormick Place South -- Room S501A, Level 5, Oral
Division of Polymer Chemistry |