Post-Treatment of Photoanodes Including Mesoporous TiO2 Beads in Dye-Sensitized Solar Cells Using Pulsed Deposition Technique

In this work, we demonstrated an efficient post-treatment of photoanodes including mesoporous TiO2 beads in dye-sensitized solar cells (DSCs) using a facile and low-cost pulsed deposition technique. As a result of the post-treatment with pulse-current (PC) anodic deposition of a TiO2 thin film, the power conversion efficiency (PCE) of a DSC based on the PC-modified photoanode is remarkably improved from 7.59% to 8.57%, due to the significantly increased its photocurrent (from 16.87 to 18.80 mA cm(-2)), which was even higher than those using the photoanodes modified with TiCl4 post-treatment (7.82%) and direct-current (DC) anodic deposition (8.28%). The improved photocurrent of the DSC with PC-modified TiO2 photoanode can be ascribed to its improved dye loading and electron transport properties. Since the TiO2 beads after the PC anodic deposition are uniformly deposited with thin layer coatings composed of TiO2 nanoparticles, and their overall surface area for dye loading is therefore increased. On top of that, a compact thin TiO2 layer directly deposited on the exposed surface of conductive oxide layer and the TiO2 beads crosslinked with deposited TiO2 nanorods significantly reduce the corresponding interfacial resistances, thus constructing the efficient pathways for electron transport within whole TiO2 photoanode. (C) 2015 The Electrochemical Society. All rights reserved.