Dye-sensitized solar cell with spray coated TiO2 electrode

Abstract

Dye-sensitized solar cells (DSSC) with spray-coated TiO2 electrode were studied. TiO2 was prepared by a sol-gel method and was sprayed onto a conducting glass using an ultrasonic spray coater. Other components of the DSSC included N3 dye as a sensitizer, iodide/triiodide redox couple as an electrolyte, and a sputtered platinum film on conducting glass as a counter electrode. The effects of sintering temperature and thickness on the efficiency of the dye-sensitized solar cell were investigated. The highest efficiency of single-layered TiO2 electrode was obtained when sintering temperature was 400℃ and the thickness of TiO2 film was approximately 11.1 μm. Raising the sintering temperature increased the short-circuit current density due to increases in crystallinity and interparticle connections, in spite of the fact that the amount of dye adsorbed on the electrode sintered at 400℃ was less than that on the electrode sintered at 300℃. When a double-layered TiO2 electrode was employed, the efficiency of the solar cell was higher, compared to a single-layered TiO2 electrode with similar specific surface area. Double-layered TiO2 electrode was fabricated to increase the light scattering. The highest efficiency of the solar cell with a double-layered TiO2 electrode was obtained when the first layer of the electrode was sintered at 400℃ for two hours and the second layer was sintered at 350℃ for 15 minutes with a thickness of ca. 11.1 μm.