Fabrication of TiO 2 Based Microspheres By Spray Drying Method and Their Application for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) have received considerable attention since Grätzel et.al. reported a high conversion efficiency using nanocrystalline mesoporous TiO 2 film. A typical DSSC consists of a transparent conductive oxide, semiconductor oxide, dye sensitizer, electrolyte and counter electrode. The working electrode is a nanoporous semiconductor oxide that is placed on conducting glass and is separated from the counter electrode by only a thin layer of electrolyte solution. The photoanode of DSSCs is typically constructed using a thick film (~20 μm) of TiO 2 or, less often, ZnO or SnO 2 nanoparticles. The TiO 2 film has a large inherent absorptive surface area for light scattering. Recently, TiO 2 microspheres are of great interest for a great deal of applications, especially in the solar cell field. Because of their unique microstructure and light-scattering effect, TiO 2 microsphere-based solar cells often exhibit superior photovoltaic performance. Hence, exploring new suitable TiO 2 microspheres for high-efficiency solar cells is essential. In this study, we reported the fabrication of TiO 2 microspheres by a simple spray drying process, and applied for Dye-sensitized Solar Cells. TiO 2 Microspheres were fabricated by spray drying method. TiO 2 paste was prepared as follows, TiO 2 microspheres (0.2g) was mixed into ethanol (1.8g). The resulting TiO 2 paste was printed by doctor blade method on fluorine-doped SnO 2 -coated (FTO) glass electrodes and sintered at 500 °C for 30 min. DSSCs were prepared by a conventional procedure. We are successfully fabricated TiO 2 microspheres by spray drying method. According to SEM images of the TiO 2 microspheres, particle size was ca. 3mm. We made microsphere TiO 2 based DSSCs, and their energy conversion efficiency was 6.5% under AM 1.5 simulated full sunlight (100 mW cm −2 ) illumination.