| Dye-sensitized solar cell (DSSC) is a new type of the photoelectrochemical solar cell. Because of its simple fabrication procedure, low cost, better stability and cleanliness, DSSC has aroused world researches and application prospect. Nano-TiO2 film is an important part of the dye-sensitized solar cell. Its structure has great impact on cell's photoelectric performance. In this paper, The surface and crystal structure of the TiO2 films were analyzed by X-ray diffraction, scanning electron microscope and transimission electron microscope.The preparation of TiO2 film and influence to the efficiency of the cells was studied by testing performance of photoelectricity, and the possible solutions were presented.The main contents and results of this dissertation are listed as following:1. In this paper, the influence of preparation methods on the microstructure of nano-TiO2 films was studied. Four methods including spin-coating, electrophoretic deposition, doctor-blade and screen-printing were used to prepare TiO2 films. Comparing their microstructures, we can know that different methods gain different microstructures. Different structures of TiO2 films act differently. This paper tells people to choose appropriate method to fabricate a needed structure.2. In the fabrication of TiO2 film electrodes for dye-sensitized solar cells using screen-printing technique, the composition of TiO2 slurry plays an important role in film microstructure and J-V curve of the solar cells. One of anhydrous TiO2 slurry was used to prepare anode film by screen-pringting technique in this paper, and it was applied in dye-sensitized solar cells. Experimental results show that the addition of Triton X-100 can influence the morphology of TiO2 film obviously as well as the performance of solar cell. It could be concluded that deficient or excessive addition of Triton X-100 would result in the decrease of open circuit voltage, short circuit current, fill factor and conversion efficiency. Good performance of solar cell can be obtained at the PEG-2000 amount of 0.8g around or Triton X-100 amount of 0.2～0.8ml in 3g P25. The J-V curve measurement was performed using a standard solar simulator (AM1.5 spectrum, 100mW/cm2), the photoelectric conversion efficiency of 3.2% was obtained in active area of 0.28 cm2.3. Nanometer TiO2 was prepared from titanium butyrate by sol-gel process. This paper studies the best way to prepare the nanometer titanium dioxide, such as the relationship between different pH and gel time,grain size. The TiO2 powders mixed with triton X-100 and acetyl acetone were screen-printed onto ITO, then sintered at 450 oC for 30 minutes to form porous photoanode of dye-sensitized solar cells. A solar cell with active area of 0.28 cm2 was assembled with N719-coated nanotube-TiO2 electrode, Pt-coated ITO glass and iodide-based ionic liquid electrolyte. The J-V curve measurement was performed using a standard solar simulator (AM1.5 spectrum, 100mW/cm2), the photoelectric conversion efficiency of 3.22% was obtained.4. TiO2 nanotubes were synthesized from commercial rutile powder by means of the hydrothermal method in alkaline solution at temperature of 150 oC for 48 hours. From morphology evolution of nano powders treated at different temperatures, the growth of nanotubes due to the crispation of nanodisks was proposed. The TiO2 nanotubes mixed with triton X-100 and acetyl acetone were screen-printed onto ITO, then sintered at 450 oC for 30 minutes to form porous photoanode of dye-sensitized solar cells. The J-V curve measurement was performed using a standard solar simulator (AM1.5 spectrum,100mW/cm2), the photoelectric conversion efficiency of 2.17% was obtained in active area of 0.28 cm2. A further development direction was offered to TiO2 film electrodes.
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