The Studies Of Ester Substituted Copper Phthalocyanines And Their Composites

In Chapter 1, the recent progresses in synthesis, thin film fabrication and applications in the materials of phthalocyanine (Pc) and their derivatives were summarized, which followed by a proposal of the researching theme in this thesis: to improve the solubility in organic solvents, probing a simpler and more efficient method of synthesizing substituted Pc; fabricating organic semiconductor composite materials based on substituted Pc by simple solution blending method and studying the relationship between structure and properties of the composites further.Ester substituted CuPc were synthesized by the phase transfer catalyzed reaction in Chapter 2. Ester substituted CuPc with the deferent length of substituent group were synthesized by the same method. Because of the difference in the substituent group length of these compounds, the morphology and the congregation of the molecules in their casting films is different, leading to the different photoconductivities of them. The Langmuir-Blodgett (LB) film of ester substituted CuPc were fabricated subsequently. Changes in it - A curves and the morphology of LB films indicated that the difference in the substituent groups length of ester substituted CuPc led to the different film-forming characteristic of them. The gas sensing devices were fabricated by LB technology and the measured gases were tri-methyl-amine (TMA) andmethanol (CH3OH).In Chapter 3, the multi-wall carbon nanotubes (MWCNTs) bonded with dodecyl ester groups were obtained by chemical modification. The modified CNTs showed improved solubility in organic solvents. The ester substituted CuPc/ modified CNTs composite was fabricated by simple solution-blending method. The photo sensitivity of the dual-layer photoreceptor with ester substituted CuPc/ modified CNTs composite as charge generation material was higher than that with pristine ester substituted CuPc, and increased with increasing the content of modified CNTs in the composites. The optimal performance was obtained when the weight ratio of doped CNTs was 8%. The efficiency of charge carrier separation increased as well due to thephotoinduced charge transfer from ester substituted CuPc to modified CNTs, which might also contribute to the improved photosensitivity of the ester substituted CuPc/ modified CNTs composite. The hybrid LB film of ester substituted CuPc/ modified CNTs were fabricated subsequently. Because of the presence of ester substituted CuPc, the aggregation of modified CNTs was confined and the tropism of modified CNTs was obtained. After doping the modified CNTs, the sensitivities to TMA of ester substituted CuPc decreased.Ester substituted perylene were synthesized by the phase transfer catalyzed reaction in Chapter 4. The ester substituted CuPc/ ester substituted perylene composite was fabricated by solution-blending method. The photosensitivity of the dual-layer photoreceptor with ester substituted CuPc/ ester substituted perylene composite as charge generation material was higher than that with pristine ester substituted CuPc, and increased with increasing the content of ester substituted perylene in the composites. It was explained that, as demonstrated by XRD and the morphology of casting films, the bulk heteroj unction formed in the composites (ester substituted CuPc as P material and ester substituted perylene as N material). Furthermore, the adsorption spectra of ester substituted CuPc and ester substituted perylene were complementary, which might contribute to the improved efficiency of light adsorption. The hybrid LB film of ester substituted CuPc/ ester substituted perylene were fabricated subsequently. As shown in n - A curves, the degree of symmetry in molecule structure of two kinds of materials effected on their film-forming characteristic. In addition, the morphology of LB film changed greatly compared to that of casting film, indicating that the structure of composites film could be affacted by the fabrication method of thin film.