Research On High Efficiency Of Dye-sensitized Solar Cells

The third-generation inorganic-organic thin film solar cells have emerged as one of the most promising solar cells due to their simple fabrication process, environmental-friendly materials, and low-cost technique. Dye-sensitized solar cells (DSCs) has been regarded as very promising solar cells as the third-generation inorganic-organic thin film solar cells. With the numerous efforts from worldwide scientists, the PCEs of DSCs has been updated to 13%, respectively. For purpose of industrialization, however, we still need to enhance their photovoltaic performance. In view of this, the research focus will be concentrated on improving the photovoltaic performance of inorganic-organic thin film solar cells. This thesis aims at developing highly efficient metal oxide semiconductor nanomaterials as photoanodes, high-efficiency and low-cost tungsten oxides counter electrodes (CEs), and finally novel photoelectric devices are also involved. We prepared a series of highly efficient nanocrystalline metal oxide semiconductor materials, including N-Ag-doped TiO2 and WO2.72 nanomaterials for dye-sensitized solar cells (DSCs). Via solid-phase synthesis, cost-effective and non-toxic perovskite materials were synthesized and applied into the systems of DSCs. The structure and performance of the photoelectric devices were further designed and optimized.We investigated the morphology control and optimization of N-Ag-doped TiO2 nanomaterials, as well as their performance in the photoanodes of DSCs. We prepared N-Ag-doped TiO2 using wet method, which improved the efficiency of DSCs by 8%.We investigated the effect of silver dopant amount on the performance of N-Ag-doped TiO2 photoanodes. The research results showed that the effect of surface plasmon resonance absorption with nitrogen and silver dopant in DSCs made photoanode the absorption of light enhanced significantly, contributed to an improved photovoltaic performance.Secondly, high-efficiency and low-cost tungsten oxides CEs were exploited. The influence of chemical composition, morphology and surface structure in tungsten oxides CEs on catalytic activity and photoelectric property were investigated in detail.To further reduce the cost and improve the stability, WO2.72 CEs were successfully prepared by means of hydrothermal synthesis. Their catalytic activity in iodine electrolyte and photoelectric property in DSCs were investigated. The surface elemental composition of the counter electrodes fabricated from WO2.72 nanorod was studied by X-ray photoelectron spectroscopy (XPS), and its catalytic activity was studied by Cyclic-voltammetry (CV).The I3-/I-based electrolyte,dye-sensitized solar cell (DSCs) fabricated from these counter cathodes exhibited an excellent photoelectrical performance, with an energy conversion efficiency of 6.48%, which is much higher than that of WO3 as counter cathodes, reaching the 85% of that from Pt-counter cathodes. These results showed that the high possibility that WO2.72 replacing Pt to develop high-performance DSC.Finally, perovskite materials as CEs were used in the system of DSCs. The photoelectric performance of DSCs was researched, to analyze the possibility of this material in the use of DSCs and application prospect.