Preparation And Application Of TiO₂ Thin Films For Dye-Sensitized Solar Cells

Dye-sensitized nanocrystalline solar cell (DSSC) is a new type of photoelectric chemical soalr cell with simple preparation procedure, low cost, ample area and friendly to environment, which make it a hot research and a good prospective application. It makes sense in research dye-sensitized solar cells not only in the aspect of groping the manufacture way for low cost and high performance solar cells but also in the aspect of its scientific values in the fields such as semiconductor photoelectronics, nanometer porous materials, the theory of material interface and photoelectric chemistry. In this paper, the TiO₂ colloid were prepared by hydrothermal and sol-gel methods respectively. The annealing temperature and the thickness of porous films on the performances of dye-sensitized solar cells were discussed in order to enhance the photoelectric conversion efficiency. There are some major works are shown as follow:(1) TiO₂ colliod was prepared from tetrabutyltitanate, acetic acid by hydrothermal method at 200 oC for 12 h, and then calcined at 450 oC for 0.5 h. Based on the film, Zn²⁺,Ni²⁺,Co²⁺,Cu²⁺ modifized TiO₂ film electrodes were prepared respectively. Under irradiation of simulation sunlight (100 mW/cm²), the influences of heating temperature, differernt metal ions and the thickness of films on the photoelectric properities of dye-sensitized solar cells have been studied. The results show that there are better photoelectric propreties when the TiO₂ film is modifized by zinc ion, its photovoltaic attained 0.822 V and under the condition of concentration of 0.08 mol/L of Zinc ion, heat treatment at 450 oC for 30 min and the thickness of 6.78μm.(2) TiO₂ colloid was prepared from tetraisoprpyl polystyrene orthotitanate modified with acethylacetone/tween-20 by sol-gel method and then calcined at 450 oC for 0.5 h. Under irradiation of simulation sunlight (100 mW/cm2), the influences of heat temperature, the ratio of TiO₂/tween-20 and the thickness of films on the photoelectric properties of dye-sensitized solar cells have been studied. The results show that there are better photoelectric properties under the conditions of the ratio of 4:1, heat treatment at 500 oC for 30 min and the thickness of 9.81μm.(3) TiO₂ colloid was prepared from tetrabutyltitanate, acetic acid by hydrothermal method at 200 oC for 12 h. TiO₂ ordered nanopowder were prepared from P25 by ultrasonic-hydrothermal method. The film electrodes were prepared with the mixtured colloid and then calcined at 450 oC for 0.5 h. Under irradiation of simulation sunlight (100 mW/cm2), the influences of heating temperature, the ratio of power/colloid and the thickness of films on the photoelectric properties of dye-sensitized solar cells have been studied. The results show that there are better photoelectric properties under the condition of the ratio 1:2.35, heat treatment at 450 oC for 30 min and the thickness of 6.85μm.