We report on the triplet spectra and dynamics in two types of oligomeric films deposited by two different techniques: thermal evaporation and spin coating. The different molecular arrangement in both films is manifested in a red shift of the absorption, PL, and T-1-T-n absorption spectra of the sublimated film relative to the spin-coated one. Triplet recombination dynamics studied with steady-state photoinduced absorption (PA) spectroscopy follow a dispersive bimolecular recombination model away from the trap filling regime. We obtained values for the triplet bimolecular recombination ratio (beta) of 3.4 x 10(-14) and 1.1 x 10(-15) cm(3) s(-1) for evaporated and spin-coated film, respectively, the difference being attributed to diverse molecular arrangement in both films.
Molecular packing effects on the optical spectra and triplet dynamics in oligofluorene films
Toffanin Stefano;Capelli Raffaella;Muccini Michele;
2008
Abstract
We report on the triplet spectra and dynamics in two types of oligomeric films deposited by two different techniques: thermal evaporation and spin coating. The different molecular arrangement in both films is manifested in a red shift of the absorption, PL, and T-1-T-n absorption spectra of the sublimated film relative to the spin-coated one. Triplet recombination dynamics studied with steady-state photoinduced absorption (PA) spectroscopy follow a dispersive bimolecular recombination model away from the trap filling regime. We obtained values for the triplet bimolecular recombination ratio (beta) of 3.4 x 10(-14) and 1.1 x 10(-15) cm(3) s(-1) for evaporated and spin-coated film, respectively, the difference being attributed to diverse molecular arrangement in both films.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
