Researches on the photoconductivity and UV-visible absorption spectra of the first C-60-chemically modified poly(N-vinylcarbazole)

Addition of Cao moiety, a powerful electron acceptor to poly(N-vinylcarbazole) by chemical reaction results in the marked enhancement in photoconductivity relative to pure PVK and C-60/PVK mixtures (C-60-doped PVK). The photo-induced discharge rates for pure PVK, C-60-chemically modified PVK(C-60-PVK copolymer) and C-60-doped PVK under the same experimental conditions are found in the following order: C-60-PVK copolymer >C-60-doped PVK>pure PVK. The photoconductive performance in C-60-PVK copolymer is closely related to fullerene level. The C-60-PVK copolymer, which has a visibly earthy yellow cast when compared with the unreacted polymer, has a new structure in the UV-Vis absorption spectrum with the active range extending from about 280 to 870 nm. A qualitative comparison of the submicro-morphological structures for PVK, C-60, C-60-PVK and C-60-doped PVK is given.