27 April 1988 Luminescence Studies Of Energy Transfer, Relaxation, And Aggregation In Molecularly Doped Polymer Films
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Proceedings Volume 0910, Fluorescence Detection II; (1988) https://doi.org/10.1117/12.945433
Event: 1988 Los Angeles Symposium: O-E/LASE '88, 1988, Los Angeles, CA, United States
Abstract
Laser excited phosphorescence spectra were used to probe the structure and energy transfer dynamics of molecules embedded in a polymer film. The systems studied consisted of 4,4'-dibromobenzophenone (DBP) and 4,4'-bromochlorobenzophenone (BCB) doped into polystyrene films. The processes of direct donor-acceptor energy transfer and spectral diffusion were investi-gated. From the donor-acceptor energy transfer kinetics, a fractal dimension of 2.4 was found to characterize the topology of the donor-acceptor system in the polymer matrix. For these experiments, the acceptor was 1,4-dibromonaphthalene. For BCB, aggregation occurs abruptly around a concentration of 12% by weight. This transition is reminiscent of percolation, and a statistical percolation-like model describes the concentration dependence of the aggregation process. Rapid spectral diffusion was found to occur in the aggregates at 4.2 K. The spectral diffusion appears to involve relaxation to low energy states in the interior of the aggregate, and energy transfer from molecules on the boundaries of the aggregate to discrete molecules outside the aggregate.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David M Hanson, "Luminescence Studies Of Energy Transfer, Relaxation, And Aggregation In Molecularly Doped Polymer Films", Proc. SPIE 0910, Fluorescence Detection II, (27 April 1988); doi: 10.1117/12.945433; https://doi.org/10.1117/12.945433
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