The Investigation Of The Dye-sensitized Solar Cells Based On The Water Electrolytes

DSSCs are composed of transparent conductive glass of FTO, photoanode, lightsensitive dye, nono-TiO2film, counter electrode and the electrolyte. DSSCs filled with theclassic electrolytes such as acetonitrile (AN) and methoxypropionitrile (MPN), usuallysuffer from the potential problem of leakage in application. Therefore, solid stateelectrolytes can solve this drawback. In addition, AN and MPN are very toxic. In order toovercome the problems mentioned above, we synthesized the all solid-state electrolytesbased on organic ionic liquid crystals with efficient light-scattering properties。And ionicsurfactants added aqueous electrolytes and agarose electrolytes were synthesized andapplied for DSSCs. The main contents are as follows:(1) Water as the earth abundant, inexpensive and non-toxic resource, can replace thetoxic organic solvent, AN and MPN for instance, and be used for fabricating aqueousDSSCs. Meanwhile, water usually shows high interfacial tension which may lead to theweek interfacial contact between aqueous electrolyte and TiO2film and the increasedinterface recombination resistances. Here, several ionic surfactants were added to the I/I3based aqueous electrolyse respectively, to solve the problem. Finally, with the addition of0.2wt%of N,N,N-trimethyl-3-(perfluorooctylsulfon-amido) propan-1-aminium iodide(FC-134) in aqueous electrolyte, PCE of3.96%and4.66%were obtained under thesimulated air mass1.5solar spectrum illumination at100mW cm2and50mW cm2.(2) DSSCs based on water electrolytes also suffered from the dra wbacks of thevolatility and potential of leakage in the application. According on the problem mentionedabove and the studies we had done, hydrogel electrolytes based on agarose were preparedand applied for DSSCs. We also investigated the influence of the variation I2and I concentrations on the devices performance. In addition, the hydrogel electrolytes with thewater as the basic component, would suffer the effect of crystallization resulted for thefreeze at low temperatures. While previous studies had indicated that the crystallization ofelectrolyte would hinder the flling of solid electrolyte into the TiO2porous structure and make device receive the reduced photoelectrochemical parameters for the result. Therefore,two normal antifreezing agents (ethylene glycol (EG) and potassium acetate (KAC)), andlithium acetate (LiAC) were added to the hydrogel electrolytes to address the limitation offreeze by lowing the freezing points. As expected, the devices based on the antifreezingagents doped hydrogel electrolyte showed the better devices performance than thosewithout adding antifreezing agent. Finally, device with the optimized electrolyte containing0.08M I2,0.2M NaI and7wt%agarose, received the highest conversion efficiency of1.54%under simulated AM1sun solar irradiation,(3) Two kinds of Cyanobiphenyl functionalized imidazolium type organic ionic liquidcrystals (OILCs) and an organic ionic crystal (OIC) were synthes ized and applied assolid-state electrolytes for DSSCs. The resultant solid-state electrolyte DSSCs based on theOILC of [C11BIm][BF4], exhibited overall power conversion efficiencies (PCE) of4.22and4.75%under1.5solar spectrum illuminations at100and50mW cm2, respectively,due to the enhanced light harvest capability of the OILC-based electrolyte.