Application Of Phosphate Ester And Tetrabutyl-piperazine Iodide In DSSCs

For the problems of electrolyte in Dye sensitized solar cells (DSSCs), Some researches are presented in this paper.To solve the problem of poor electronic contact between hole transporting materials and the nanoporous semiconductor films, Triphenylamine phosphate ester with different phosphate ester is synthesized. Instead of common liquid electrolyte, It can also solve the problems of volatilizable solvent and h erode the Pt electrode. These compounds are identified by MS and NMR. Then photoelectrocheimical properties and their performance on DSSCs are studied. These hole conducters cannot be used to electrolyte in DSSCs based on N719 dye because of the dismatch of the energy levels. They will show well performance when they are applied in DSSCs based on the suitable dye with more positive HOMO(>1.2 V vs. NHE).To solve the problem of durability of DSSCs that is mainly caused by volatile electrolytes, a nonvolatile electrolyte system is established based on four newly developed phosphate ester compounds. They show good properties such as low viscosity, high boiling point, appropriate electrochemical window, nonparticipation in electrode reaction and well solubility for electrolyte. Optimum operation condition of DSSCs based on this kind of electrolyte is also discussed. The results show the good performance at high temperature compared with MOPN electrolyte solvent. It suggests that these compounds can replace normal low boiling point electrolyte solvent. Thus, this is an important step towards the actual application of liquid DSSCs.To increase the optional cationic variety in electrolyte, 1, 1, 4, 4-tetrabutyl-piperzine iodide (TBPI) is synthesized by different methods and its structure is identified by MS, NMR and X-ray single crystal diffraction. Solid DSSCs based on it and succinonitrile show poor performance (less 0.1%). Efficiency of 2% is achieved based on electrolyte solvent of 3-methoxypropionitrile and malononitrile. The performance could not enhance because of poor solubility of TBPI.