Quenching of exciplex and charge-transfer complex fluorescence of poly(N-vinylcarbazole)– benzanthrone system

Autor: R.M. Siegoczyński, W. Ejchart
Rok vydání: 2004
Předmět:
Zdroj: Macromolecular Symposia. 212:575-580
ISSN: 1521-3900
1022-1360
DOI: 10.1002/masy.200450875
Popis: When benzanthrone (Bt), a weak electron acceptor, is doped into poly(N-vinylcarbazole) (PVCz) solution or film, an excited carbazole chromophore (D*) interacts with Bt to form a new exciplex state, which gives a broad fluorescence band (λ max = 440 nm) in solution and a new state, which gives broad fluorescence (λ max = 550 nm) in the film. In order to elucidate the origin of these new states, we have studied the results of experiments for absorption, concentration dependence of the excimer and exciplex fluorescence quenching, both in solution and in the film, and electric field-induced fluorescence quenching in the film. Taking into account that (i) the new state formation in the PVCz film containing small amounts of Bt enhances the photocurrent in the absorption region, where the photon energy is insufficient to excite polymer molecules directly into the conduction state, (ii) the 550 nm fluorescence of the PVCz - Bt system in film is only partly quenched by electric field, (iii) the appearance of structureless tail in the fluorescence excitation spectrum, the charge transfer interaction model of the PVCz - Bt system in film is proposed.
Databáze: OpenAIRE
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