We report femtosecond transient absorption results for solutions and thin films of a substituted oligomer of poly(paraphenylene vinylene) performed over wide spectral and pump-intensity ranges. Solutions and films exhibit a photoinduced absorption (PA) band with dynamics matching those of the stimulated emission, demonstrating unambiguously that these features originate from intrachain singlet excitons. Thin films exhibit an additional short-wavelength PA band with pump-independent dynamics, indicating the formation of non-emissive interchain excitons. Correlations in the dynamics of the two PA features, as well as the intensity-dependence, provide strong evidence that the formation of interchain excitons is mediated by intrachain two-exciton states.
|Number of pages||9|
|Journal||Chemical Physics Letters|
|Publication status||Published - Oct 3 1997|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Atomic and Molecular Physics, and Optics