Electrophoretic Deposition of TiO2 Layers for Dye-Sensitized Solar Cells

• Main Authors: Li-ChuanYang, 楊力權
• Other Authors: Ming-Chang Yang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/46419799854365134713

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 101 === Abstract By taking the advantage of the binder-free system, we use electrophoretic deposition (EPD) technique to prepare nanocrystalline TiO2 films, which had a closely packed structure, for dye-sensitized solar cells (DSSCs). EPD provided an adequate electrical field to deposit TiO2 particles on conductive substrate, resulting in a closely packed structure. By EPD method, TiO2 films could achieve a smaller volume with the same specific surface area with smaller volume. This characteristic can be developed on the procedure of micro-device. Secondary hydrothermal method was used to transform the phase of commercial TiO2 particles into pure anatase phase. The TiO2 particles of pure anatase phase could effectively enhance the photocurrent density of the dye-sensitized solar cells and its cell performance could achieve 6.58%. In order to enhance the injection amount of photons, three larger commercial TiO2 particles (P25, A160, R400) were added into TiO2 films with weight ratio 25% for a thickness of 10μm thickness. The results showed that the addition of A160 in TiO2 films gave the best current density, 15.2mA/cm2, and the cell performance could achieve 8.29%. A series of optimization tests, including the necessity of scattering layer in the TiO2 films, different weight ratio of A160 TiO2 particles in the film and different thickness of TiO2 films, were carried out. The result showed that TiO2 film of 13μm thickness without scattering layer at the with weight ratio of 25% gave the best cell performance of 8.65%. Intensity-modulated photocurrent spectroscopic and impedance analysis showed that the mixing TiO2 films had shorter electron transit time. The reason was that scattering effect shortened the electron transit distance. It resulted in good charge collection efficiency and cell performance. Key word: Dye-sensitized solar cells, EPD, TiO2 layers, scattering effect