Temperature Dependence in the Surface Treatment of Photoelectrode on the Performance of Dye-Sensitized Solar Cells

Abstract

The temperature dependence in the surface treatment of TiO₂photoelectrode on the photovoltaic properties of dye-sensitized solar cells (DSSCs) was studied. A nanoporous TiO₂electrode was modified with aqueous NaOH solution by simple dip coating process at varied temperatures and dipping time, and then applied to DSSCs. Throughout the optimization of surface-treatment temperature (40 °C) and time (10 min), we obtained a higher power conversion efficiency (PCE) of 7.7% in DSSC with NaOH-modified TiO₂layer, compared to that (6.81%) of reference device with bare TiO₂. The enhancement in PCE was attributed to an increase in open circuit voltage due to a negative shift of conduction band edge, arising from the anion formation on TiO₂surface.

Keywords:

• Dip coating
• dye-sensitized solar cell
• NaOH
• negative band shift
• surface treatment

Acknowledgment

This work was supported by research grants from the Catholic University of Daegu in 2012.