Preparation And Properties Of Dye-sensitized Titanium Films Electrode

In the thesis, the principle, problems and prospect of the wet-type solar cells were reviewed. Polymers were added in the initial solution to adjust the microstructure of films and to improve the adsorption of dye.Titania films were prepared by the sol-gel dip-coating method, with polyethylene glycol(PEG) and hydroxypropylcellulose(HPC) used as the additives. The FTIR spectra were employed to investigate the anchoring mechanism of HPC on the titanium colloid. The microstructures of the films were analyzed by electrical microscope (SEM and TEM), ellipsometry and X-ray diffraction (XRD). The optical absorption spectra were used to investigate the dye adsorption property and the photoelectrochemical properties of titania films were measured via I-V analyzer. From the investigation of titania films with PEG as additive, several significant conclusions could be drawn: Titanium dioxide films with porous microstructure could be prepared using PEG as additive; almost no conglomeration were observed with the titanium particle ; the microstructure of titania films could be modulated by the amount of PEG and treating temperature; at the same time, the porosity of the film improved with the increase of PEG; For the specimen treated at different temperatures, the greatest porosity could be achieved when treated at 500癈; The adding of PEG could greatly increase the dye adsorption amount. In this work, the dye adsorption reached its highest value with the sample of the greatest porosity , with the fill factor (FF) of that sample was 0.359. Also, it was demonstrated that titanium films with PEG as additive showed better photoelectrochemical properties than titanium films without PEG.For the titania films with HPC as additive, we had the following opinions: Titania films with the particle size ranging from 20nm to 120nm could be obtained with HPC as dispersant; A little amount of HPC promoted the formation of a loose structure of the films and the decrease of particle size; The particle size hit the lowest point when the amount of HPC was 3m; The structure of titania films became denser and the particle size increased with further adding of HPC in the solution. When the-3 -particle size was small, the aberration of crystal lattice appeared and the bandgap energy increased, which resulted in the blue shift of absorption in the spectrum. The mechanism of HPC's influence on the microstructure was studied via FTIR spectrum. The adsorption of the dye on the titania films is affected by the amount of HPC. The adsorption amount was greatest when the amount of HPC was 3m, with FF was 0.59. FF of the HPC added titania film was better than that of the PEG added film and the films without any additives.At the basis of the above research, the sample with highest fill factor was chosen as electrode to fabricate solar cell. The FF was 0.393 and the n was 0.3%. the reason why FF and n. were lower than other solar cells was that the resistance of conducting substrate was high and the losses in the fabrication of the batteries .The bicomponent films electrode was brought forward. The TiCVWOs bicomponent film was fabricated and the photoelectrochemical property was measured. The result showed that fill factor of bicomponent films electrode was higher than fill factor of titania electrode.