Spatially and temporally resolved emission from aggregates in conjugated polymers.

The authors present results of cw, time-resolved, and spatially resolved spectroscopic studies of emission and absorption in a model conjugated polymer, poly(p-pyridyl vinylene) (PPyV). The red shifted film spectra suggest the formation of aggregated regions. The ∼4X redn. in emission efficiency in films vs. soln. is attributed to a longer radiative lifetime for aggregate excitons, as is evidenced by time-resolved fluorescence measurements. The authors present direct optical imaging of aggregates in a conjugated polymer via near-field scanning optical microscopy. The aggregate emission and absorption are localized to partially aligned regions of the film ∼200 nm in size. [on SciFinder(R)]