RESEARCHES ON THE PHOTOCONDUCTIVITY AND UV-VISIBLE ABSORPTION-SPECTRAOF THE FIRST C-60-CHEMICALLY MODIFIED POLY(N-VINYLCARBAZOLE)

Addition of Cao moiety, a powerful electron acceptor to poly(N-vinylca rbazole) by chemical reaction results in the marked enhancement in pho toconductivity 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 exp erimental conditions are found in the following order: C-60-PVK copoly mer >C-60-doped PVK>pure PVK. The photoconductive performance in C-60- PVK copolymer is closely related to fullerene level. The C-60-PVK copo lymer, which has a visibly earthy yellow cast when compared with the u nreacted polymer, has a new structure in the UV-Vis absorption spectru m with the active range extending from about 280 to 870 nm. A qualitat ive comparison of the submicro-morphological structures for PVK, C-60, C-60-PVK and C-60-doped PVK is given.