| A review of the development of organic semiconductor composite photo-conductive materials and devices was followed by a proposal of the researching theme in this thesis. The effects of fabrication arts such as solvents, gradient, interfacial layer and configurations on the photoconductive properties of the single-layer chlorodiane blue azo/TiOPc composite photoreceptors were systematically studied in chapter II. The results showed that the solvent played a decisive role in the multiphase and multicomponent system composed of two photogeneration species (chlorodiane blue azo and TiOPc), a transporting material (hydrozone) and polymer binder; 1,4-dioxane, as an amphiphilic solvent can effectively disperse and stabilize such multiphase and multicomponent systems, the derived photoreceptors presented improved photoconductive properties superior to those of dual-layer counterparts and demonstrated the evident synergetic enhancement and complementary effects (eg. AZO/TiOPc=8/2, CGM/CTM/PO1/120/120, (?/2) "15oonm=3.3333(lx.s)-1, (?/2)?762.5nm=3.3333(lx.S)-1).Chapter III focused on the description of the physical mechanisms associated with the synergetic enhancement and complementary effects observed in chlorodiane blue azo/TiOPc composite photoreceptors. UV-vis and XRD measurements revealed the facts that there were neither detectable electronic interactions between the two species nor interpenetration and complexion between these two components. While the ESR and XPS measurement results indicated that there happened a process of photoinduced, oriental and partial electron transfer between chlorodiane blue azo and TiOPc molecules. It was suggested that the concomitant of the independence in ground states and the interactions in excited states were ascribed to the synergetic enhancement and complementary effects uniform in the same composite photoreceptors.Based on the above theory, the fluorinone-based azo was used to prepare the single-layer photoreceptors with fluorinone-based azo/TiOPc composites in chapter IV, experimental data indicated that the photoconductivity of fluorinone-based azo/TiOPc composite photoreceptors was improved in comparison with that of chlorodiane blue azo/TiOPc composite photoreceptors, the amelioration was attributed to the more pronounced electron-acceptor characteristic of fluorinone-based azo, these results further confirmed the mechanism proposed for the synergeticenhancement and complementary effects in azo/TiOPc composite systems.In chapter V, TiOPc nanoparticles were prepared by combining the technique of direct precipitation in solution with the methodology of encapsulation into biomacromolecules. The obtained particles were characterized with TEM> AFM and UV-Visible measurements, the observation indicated that uniform and stable nanoparticles were derived from this hybrid technique. Furthermore, the radium of the particles varied systematically from lOOnm to 30nm with the increasing of the temperature. The UV-visible spectral evolution with particle radium was explained by exciton-coupling theory, it suggested that the change of crystal polymorphs was induced by nanofication-treatment. Photoinduced discharge experiments showed a trend that the higher photosensitivity was corresponding to the smaller particle radium (eg. nano-TiOPc60r,40nm/CTM/PC=l/80/100, S762.5nm=0.533cm2/u J ) ; thereby the single-layer nanoparticle TiOPc/fluorinone-based azo composite photoreceptors were prepared and their photoconductive properties were briefly studied.In conclusion, two originalities can be outlined from this thesis: (1) By using 1,4-dioxane as disperse solvent, stable and uniform composites of TiOPc, azo, hydrzone and polymer matrix were prepared, and the single-layer photoreceptors were successively fabricated with these composites, the photoreceptors showed high and wide range photosensitivity from visible to near infrared spectral regions. (2) By combining the technique of direct precipitation from solution with encapsulation into biomacromolecules, TiOPc nanoparticl...
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