Exciton Migration and Trapping at the Excimer-Forming Site in Poly (N-Vinylcarbazole)

Abstract

Optical properties of poly(N-vinylcarbazole) films and solutions are investigated by the site-selective excitation method. The localized excitons induced by the disorder are found to be generated below the energy of the exciton absorption band. The hopping of the localized exciton is found to play an important role in the dynamical process. In the films, the localized excitons hop well into the excimer-forming sites, and are observed as the excimer fluorescence. In the solutions, a fluorescence band due to the localized excitons appears in addition to the excimer fluorescence. This appearance is explained by a smaller efficiency of the exciton hopping into the excimer-forming sites than that in the film.