Blend photoluminescence spectra

Fig. 2.10 Photoluminescence excitation spectra of a PFB F8BT blend. The detection wavelengths are 465 nm (black), 540 nm (red), and 600 nm (green), corresponding to the PFB and F8BT exciton emissions and the exciplex emission, respectively. The exciplex spectrum resembles a superposition ofthe two exciton spectra, pointing towards indirect excitation of the exciplex via transfer from the excitons. The spectra were taken using a SpexNova spectrofluorimeter and are not corrected for the spectral response.

Fig. 2.48 Time-resolved photoluminescence spectra of PFB F8BT blends of different weight ratios, (a), (b) and (c), and of films of pure PFB and F8BT (d). The spectrum with the highest intensity represents the PL emission integrated over the first 10 ns. The less-intense spectra are the delayed PL integrated over subsequent 10-ns time windows, i.e. over 10-20 ns, 20-30 ns,..., 80-90 ns.

The UV-vis adsorption spectrum is an important characterization method for evaluation of electroluminescent/photoluminescent polymers employed in light emitting diodes, including polymer blends, to determine the overlap of the respective adsorption spectra and to design specific spectral emission under electroluminescent conditions [313]. 

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