Photoconductivity study of modified carbon nanotube/oxotitanium phthalocyanine composites

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 dual-layer 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.