A novel compound 2,6-diphenyl-1,5-diaza-1,5-dihydro-s-indacene (Indacene) was synthesized by means of the Madelung reaction starting from 2,5-dimethyl-1,4-phenylenediamine. The structure was characterised by NMR, IR, MS, and elemental analysis. The UV/Vis absorption and photoluminescence spectra were investigated. The electroluminescent behaviour of the new compound was studied in ITO/PEDOT-PSS/Indacene-CNPPP/Mg-Ag(10:1)/Ag devices. The electroluminescent maximum was recorded at 504 nm corresponding to a greenish blue emission. The results demonstrate the potential application of Indacene in OLEDs.

Carbon nanotubes (CNTs) bonded to dodecylamine groups were obtained by chemical modification. The modified CNTs showed improved solubility in organic solvents and miscibility with polymer matrix. The photoconductivity of oxotitanium phthalocyanine (TiOPc) doped with modified CNTs was investigated by the xerographic photoinduced discharge method. The results showed that the photosensitivity of the duallayer photoreceptor (P/R) with modified CNT/TiOPc composite as charge generation material was higher than that with pristine TiOPc and increased with increasing the content of modified CNTs in the composites. It was explained that, as demonstrated by X-ray photoelectron spectroscopy (XPS), after doping with modified CNTs, the intramolecular charge transfer occurred in TiOPc and the charge-transfer exciton was prone to be produced, which was favorable to charge carrier generation. The efficiency of charge carrier separation increased as well because of the photoinduced charge transfer between TiOPc and CNTs, which might also contribute to the improved photosensitivity of the modified CNT/TiOPc composites.

A perfluorinated perylene diimide, N,N¢-diperfluorophenyl-3,4,9,10-perylenetetracarboxylic diimide (DFPP), and its nonfluorinated analogue, N,N¢-diphenyl-3,4,9,10-perylenetetracarboxylic diimide (DPP), showed similar UV-vis absorption and fluorescence spectra when they existed as monomeric dyes in solutions, whereas in solid films they exhibited great differences. Absorption band splitting was observed for DPP film; however, for DFPP film, the fine structure of absorptions similar to that in solution still remained in addition to the absorption peaks becoming broader and shifting to longer wavelength regions. Furthermore, it was found that DFPP molecules aggregated to form a crystalline film when the temperature of the substrate was elevated to 200℃. Through the simulation of the molecular conformation, the theoretical examinations of molecular interactions, the measurement of electron affinity, the observation of the film morphology by AFM and SEM, and the crystalline structure characterization by XRD, the unique aggregate structure of the crystalline DFPP thin film was suggested: DFPP molecules stacked with the perfluorinated phenyl groups straight over or below the perylene cores of the adjacent DFPP molecules.