Preparation The Counter Electrode Of Nanocrystalline Dye-sensitized Solar Cells Via Self-assembly Method

Conventional counter electrodes of nanocrystalline dye-sensitized solar cells (NDSCs) were prepared by methods such as electrochemical deposition, sputtering and thermal decomposition. But electrodes prepared by electrochemical deposition and sputtering had the higher platinum loadings which were not in accordance with the character of low costing of NDSCs. This problem was solved effectively by the method of thermal decomposition, and its catalytic performance was higher than previous electrodes. In this paper, we describe a novel method for fabricating platinized counter electrode of NDSC, which was called self-assembly method. The present electrode had the characters of low platinum loading and high catalytic performance which was higher than counter electrodes prepared by thermal decomposition and platinum foil. The optimum techniques, micro-characterizes, surface analysis, catalytic performance, stability of the platinized electrode were investigated. The low temperature flexible counter electrode of NDSC was fabricated by self-assembly method, which dramatically reduced the cost of the NDSC.6 The counter electrode of NDSC was prepared by combining the advantages of colloid preparation , Langmuir-Blodgett film modification and self-assembly technique. The micro-characteristics, surface analysis, catalytic performance, stability of the platinized electrode were investigated.7 The platinum loading of the self-assembled platinized electrode could be effectively controlled by changing the ratio of thiol to stearic acid. The relationship between platinum loading and catalytic performance were studied.8 The silane coupling reagent ((CH3O)3Si(CH2)3SH) were anchored to FTOglass surface by forming covalent bond, and then the platinized electrode was treated with self-assembly process. Comparing with the Langmuir-Blodgett film modification, the silanization modification overcame the limitation of experiment instruments, operated simply, which were benefit for the preparation in large scale and practical application of NDSC.9 The counter electrode of low temperature flexible NDSC was prepared by Langmuir-Blodgett film modification, self-assembling of nanoclusters and heating at 140 °C in vacuum. Comparing with the conventional electrochemical deposition, room temperature sputtering method, the platinum loading was dramatically lowed, which reduced the cost of the NDSC.10 The surface composition of platinized electrodes prepared with different experimental conditions were studied by XPS. The result of XPS showed that the valence state of Pt existed on the electrodes was zero valence, and there was a small quantity of thiol on the electrode.