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Derivatives of newly synthesized aromatic polyimides containing sulphur atoms in the backbone were studied as electron-hole-transporting and light-emitting materials for use in combination with tris(8-hydroxyquinoline)-aluminium in multilayer organic electroluminescent devices. Efficient bipolar charge transport has been revealed in the polymers. Bright electroluminescence (15 000 cd m -2 at 14V) was observed in the visible range. The possible role of intermolecular donor-acceptor interactions in the mechanism of electroluminescence is discussed.

IR electroluminescence was revealed in single-layer light-emitting diodes based on a type of electroactive polymer nanocomposites-electron-hole conducting aromatic polyimide and organic nanocrystalline particles of cyanine molecules, known as J-aggregates. These materials exhibit a very narrow emission band with a maximum at 815 nm. Dramatic increase of charge-carrier mobility was observed for these layers containing the J-aggregate nanocrystalline phase.

Poly(3,3’-phthalidylidene-4,4’-biphenylilene) was investigated, for use as an electron-hole-transport layer in photovoltaic cells. The drift mobility of charge carriers decreased by one to two orders of magnitude when magnesium phthalocyanine dye molecules at 5 wt.% were dispersed into the polymer. The photovoltaic properties were studied for polymer-dye structures sandwiched between ITO and Al electrodes.

Electron and hole drift mobility in N-picrylarylamine doped polycarbonate films has been studied by the conventional time-of-flight technique. The charge transport molecules contain both electron acceptor and donor functionalities. Electron mobility is similar in value for all the systems as the electron acceptor functionality is the same in all the molecules. Hole mobility depends on the donor functionality. The results can be fit well into a correlated disorder model when energetic features of the transport molecules are also taken into account. For quantum-chemistry calculations, the semiempirical PM3 and ZINDO/S methods were used.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.