Fabrication And Properties Research On Counter Electrode Of Dye-sensitized Solar Cells

The counter electrode contributes to the main cost of dye sensitized solarcells(DSSC). Platinum is used the conventional electrode, but it is expensive, andhinders DSSC's scale production. This thesis mainly studies the optimizationcharacterization of preparation method of DSSC on the counter electrode material,and TiO2photoanodes. The Pt electrodes were prepared by thermal decompositionand electrodeposition method. The polyaniline electrode were electrodeposited onFTO through electrochemicla method. I-V test, SEM, EIS and CV were employed toinvestigate the photoelectric performance of DSSC based on different counterelectrodes.TiO2thin films photoanode were prepared by doctor-blading method, and whenthe thickness of the film was about15?m, the DSSC exhibited the best performance.The TiO2slurry were processed by ultrasonic mechanical stirring for a day, rotaryevaporation for1h, which made TiO2particles dispersed well. After heat treatment at450?for30min, TiO2photoanode were treated with TiCl4solution for30min at70?and heated it again, which could improve the surface roughness and the dyeabsorption, thus improving the photoeletric current.The Pt electrodes were made from the thermal decomposition of chloroplatinicacid solution. When the load of Pt reached100?g·cm-2, the performance was well,and much load would not result better performance, and the best temperature was420?. The Pt deposited with electrodeposition was homogeneous and the surface wasbright, which was better than Pt prepared with thermal decomposition. The optimumparameters for electrodeposition:5g/L of H2PtCl6, solution temperature at70?,electrodeposition duration time of100s, current density of40mA/cm2. The assembledDSSC exhibited the photoelectric conversion efficiency of98%Pt sheet under thesame conditions, indicating the catalytic power of it had been close to the Pt sheetelectrode.PANI were deposited on FTO glass through three electrochemical methodsseparately. The pulse potential method had the best performance. The optimalconditions for the three methods are0.7V,400s through constant potential method; ton=toff=1s,100cycles through pulse potential method;0~1V,16segments throughcyclic voltammetry at the sweep speed of50mV·s-1. Photoelectric performance testshows that the efficiency of counter electrode deposited by pulse potential method isbetter than others. The polyaniline/graphene electrode produced with CV methodexhibits higher catalytic ability than pure polyaniline, but the specific surface area andthe photoelectric conversion efficiency of it is lower.