Preparation of TiO2/Nano-metal composite particles and their applications in dye-sensitized solar cells

This study investigated the applicability of TiO2/Au (or TiO2/Ag) composite particles, which probably have the plasmon resonance effect. on FTO-glass (Fluorine doped tin oxide, SnO2:F) substrate of the working electrode of a dye-sensitized solar cell (DSSC). The dry particle coating technique was utilized to coat the surfaces of TiO2 particle with nano-sized Au (or Ag) powder particles. A layer of TiO2/Au (or TiO2/Ag) composite particles was deposited on the FTO-glass substrate of the working electrode, and it was then sintered in a high-temperature furnace. The working electrode covered with a TiO2/Au (or TiO2/Ag) thin film was kept immersed in a solution of N-719 (Ruthenium) dye for 12 h. Further, a thin film of platinum was deposited on the FTO-glass substrate of the counter electrode. Finally, the DSSC was assembled, and the short-circuit photocurrent: the open-circuit photovoltage, and the power conversion efficiency eta of DSSC were measured using a home-made I-V measurement system. This study also examined the effects of the mass ratio of TiO2 to Au (or Ag), and the duration of dry coating on the power conversion efficiency eta of the DSSC. If the duration of dry coating is adequate, the power conversion efficiency eta of the DSSC with TiO2/Au (or TiO2/Ag) composite particles increased with increase in the percentage of Au (or Ag) in the composite particles. Most importantly, this study shows that the power conversion efficiency eta of the DSSC with a film of TiO2/Au (or TiO2/Ag) on the working electrode always exceeds that of the conventional DSSC due to presence of the Schottky barrier, which is probably created in the TiO2/Au (or TiO2/Ag) composite particle. (C) 2009 Elsevier B.V. All rights reserved.