Enhanced performance of dye-sensitized solar cell via surface modification of mesoporous TiO_2 photoanode with electrodeposited thin TiO_2 layer

摘要

Surface modification of porous TiO_2 photoanode with a thin compact TiO_2 layer was carried out by means of anodic electrodeposition in an aqueous TiCl_3 electrolyte. Results indicated that the electrodeposited thin TiO_2 layer could bridge gaps between TiO_2 nanoparticles and improve the electrical contact at the FTO (fluoride-doped tin oxide)/TiO_2 interface, leading to an efficient electron transport. In addition, the thin compact TiO_2 layer could cover the exposed surface area of FTO to the electrolyte, which contributes to the suppression of the charge recombination. The surface treatment of mesoporous TiO_2 photoanode via aqueous electrochemical route is an effective way to improve the performance of DSSC (dye-sensitized solar cell), which could increase the short-circuit current density, and reduce the dark current density compared to DSSCs with bare and TiCl_4-treated TiO_2 photoanodes. The photoelectron conversion efficiency of DSSC was increased from 7.3 to 8.2% after employing the TiO_2-modified photoanode.