Research On Organic-inorganic Hybrid Materials Based On4,4’-Bipyridine

The preparation of the organic-inorganic composite based on4,4’-bipyridine is the use of the reaction of4,4’-bipyridine and halogenated hydrocarbons. In detail, halogenated hydrocarbons was added into the organic solution of4,4’-bipyridine at the inert atmosphere, the organic-inorganic hybrids was finally obtained by reacting the previous product and metal halide. Their FET channel devices have potential applications in the field-effect transistor, active-driven displays, sensor and so on.1. We have designed and synthesized a series of new organic-inorganic semiconductor materials, such asl,1’-Diethyl-4,4’-bipyridinium diiodide (A),1,1’-Dibutyl-4,4’-bipyridinium diiodide (B),1,1’-Diethyl-4,4’-bipyridinium lead iodide (C),1,1’-Dibutyl-4,4’-bipyridinium lead iodide (D) based on4,4’-bipyridine by a solution method and a vapor diffusion method and characterized by elemental analyses and infrared spectroscopy.2. Crystal structures of these hybrids were determined by a single crystal X-ray diffraction method. By studying the molecular conformation and packing characteristics. It was found that hybrid A and B display good planar structure and there are strong intermolecular interactions facilitating charge transport due to the planar structure. Hybrids A and B showed better stability since the decomposition points were far higher than those formed by halogen acids and aliphatic amines, aromatic amines.3. UV-visible absorption and emission spectra of the hybrids were measured in methanol solution (concentration1×10-5mol/L) and the thin films deposited on substrates at about25℃. The PL spectra of hybrids A and B in the film state were red-shifted as compared to those in the solution, indicating that the more effective conjugation degree and planar in the film state.4. FET using hybrid B organic-inorganic semiconductors as a channel material were fabricated. Thin film morphologies and Field-Effect transistor characteristics of the hybrid were measured at room temperature, which exhibit p-type transportation with maximum carrier mobility of0.046cm2V-1s-1and Ioff of102-103. Several facts influenced on the quality of films by spin-coating, such as solvents, solution concentrations, number of spin-coating, annealing temperatures and so on. Roughness and morphology of these films were confirmed by SEM and AFM methods.