Research On Preparation Of TiO₂ Paste And Its Application In Dye-sensitized Solar Cells

Dye-sensitized solar cell (DSSC) is a new type of solar cells. With simple fabrication procedure, low cost, stable performance and friendly to environment, it has a broad prospect of application. In this thesis, the TiO2 pastes were prepared by methods of grinding and hydrothermal synthesis respectively. Then the TiO2 pastes were coated on the conductive glass by the way of screen printing, getting TiO2 photoanode films. The photoelectric conversion efficiency of assembled cells were tested and studied. Then the TiO2 paste with best performance were used as active layer in photoanode, and on this basis, the influence of magnetron sputtering blocking layer and screen printing scattering layer on the performance of DSSC were studied, to prepare stable and efficient DSSC.About the grinding method, we investigated the effect of different TiO2 solid content on performance of TiO2 paste and DSSC. In the condition of best solid content, the influence of P25 power pre-treated with HNO3 and mixing different proportions of mesoporous TiO2 on the performance of TiO2 paste and DSSC was studied. The results show that the performance of TiO2 paste is the best when the solid content was about 18%. HNO3 pre-treatment can effectively dispersed TiO2 particles, increasing the porosity of the films. When the incorporation of mesoporous TiO2 was 20%, DSSC achieved the best performance, increasing from 5.07% to 5.47%.About the hydrothermal method, the process parameters of TiO2 paste preparation were optimized. The effects of solution concentration, PH value, hydrothermal temperature and time on the microstructures and photocatalytic activity of the TiO2 films and DSSC were investigated and discussed. The optimal parameters were determined. A high photoelectric conversion efficiency of 5.87% was achieved with optimal hydrothermal parameters, having a great improvement compared with the others. Then the stability of the paste was tested.Using the TiO2 paste with best performance as active layers in photoanode, the process of photoanode was optimized. TiO2 blocking layer was firstly deposited by magnetron sputtering on conductive glass in order to investigate the effect of blocking layers with different thickness on the performance of DSSC. Then on the basic of the blocking layer with optimal thickness, the effect of scattering layer made from 200nm TiO2 and 400nm TiO2 on the performance of DSSC was studied. The results showed that the effect of 400nm TiO2 scattering layer is more obvious. The photo’ electric conversion efficiency of the cell was increased from 6.09% to 6.85%, increasing by 12%.