PHYS 510 |
| Composite nanoparticles based on regioregular poly (3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) were fabricated using the reprecipitation method. With PCBM doping level increase, nanoparticles size increases through transmission electron microscopy and dynamic laser scattering analysis. The optical properties of single nanoparticles were characterized by single particle imaging and spectroscopy. We find that emission maxima of nanoparticles with different doping levels of PCBM are unaffected by the level of PCBM doping, but spectral shapes show distinct changes. The vibronic structure of emission spectra collected for single composite particles consistently changes with PCBM doping levels, and implies changing order of individual P3HT molecules in the nanoparticles. These observations are masked in bulk fluorescence experiments, but are revealed by single particle spectroscopy, and have implications for the current understanding of active layer morphological and spectral properties in Bulk Heterojunction Organic Photovoltaic Devices based on conjugated polymers. |
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PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Physical Chemistry |