Fabrication of TiO2 Based Microspheres By Spray Drying Method and Their Application for Dye-Sensitized Solar Cells

Abstract

Dye-sensitized solar cells (DSSCs) have received considerable attention since Grätzel et.al.reported a high conversion efficiency using nanocrystalline mesoporous TiO2 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 TiO2 or, less often, ZnO or SnO2 nanoparticles. The TiO2 film has a large inherent absorptive surface area for light scattering. Recently, TiO2 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, TiO2 microsphere-based solar cells often exhibit superior photovoltaic performance. Hence, exploring new suitable TiO2 microspheres for high-efficiency solar cells is essential. In this study, we reported the fabrication of TiO2microspheres by a simple spray drying process, and applied for Dye-sensitized Solar Cells. TiO2 Microspheres were fabricated by spray drying method. TiO2 paste was prepared as follows, TiO2 microspheres (0.2g) was mixed into ethanol (1.8g). The resulting TiO2 paste was printed by doctor blade method on fluorine-doped SnO2-coated (FTO) glass electrodes and sintered at 500 °C for 30 min. DSSCs were prepared by a conventional procedure. We are successfully fabricated TiO2 microspheres by spray drying method. According to SEM images of the TiO2 microspheres, particle size was ca. 3mm. We made microsphere TiO2 based DSSCs, and their energy conversion efficiency was 6.5% under AM 1.5 simulated full sunlight (100 mW cm−2) illumination.