SPATIALLY AND TEMPORALLY RESOLVED EMISSION FROM AGGREGATES IN CONJUGATED POLYMERS

We present results of cw, time-resolved, and spatially resolved spectr oscopic studies of emission and absorption in a model conjugated polym er, poly(p-pyridyl vinylene) (PPyV). The redshifted film spectra sugge st the formation of aggregated regions. The similar to 4X reduction in emission efficiency in films vs solution is attributed to a longer ra diative lifetime for aggregate excitons, as is evidenced by time-resol ved fluorescence measurements. We present direct optical imaging of ag gregates in a conjugated polymer via near-field scanning optical micro scopy. The aggregate emission and absorption are found to be localized to partially aligned regions of the film similar to 200 nm in size.