Preparation and performance of porous electrodes for dye-sensitized solar cells

The spraying method, by which slurry preparation is simple, easy to operate and low cost, was applied to prepare photo-anodes for dye-sensitized solar cells. Nano-TiO₂ thin films were prepared by a colloidal spray coating technique, and the spraying slurry mainly included tetra-n-butyl titanate (TBT) and P25. Ethylene glycol (EG) was selected as a pore-forming agent to investigate its optimum addition. Through analyzing the I-V curves of the cells, the roughness, dye adsorption amount and diffuse reflection spectra of the thin films, and the scanning electron microscopy images and electrochemical impedance spectra of the photo-anodes, we draw the following conclusions. When the ratio of EG to TBT is 1:1 by volume, the thin film reaches the largest surface area, the dye adsorption amount is 1.47×10^-7 mol·cm^-2, and the cell has the best performance with the open-circuit voltage of 0.69 V, the short circuit current of 13.0 mA·cm^-2, and the photoelectric conversion efficiency of 5.38%. The photoelectric conversion efficiency is nearly two times that without the pore-forming agent, and now the electron transfer resistance is the least.