Deposition and characterisation of titanium dioxide films formed by electrophoretic deposition

Abstract

Nanocrystalline titanium dioxide (TiO2) films were deposited on glass substrates by electrophoretic deposition (EPD). Films were grown using the constant current and constant voltage methods and key EPD parameters were investigated. Anatase TiO2 powder, dissolved in deionised water with iodine and acetylacetone as dispersing agents was the colloidal suspension utilised. TiO2 particle concentration of 1 gl–1 and films annealed at 100°C exhibited the best properties. As the applied voltage and current densities increased, the film thickness increased. Thickness of the TiO2 films increased linearly during the initial period of EPD but the deposition rate subsequently decreased and attained a constant value for longer durations. At higher applied voltages and current densities, as-grown films were discontinuous with cracks. Optical measurements were used to determine the band gaps of deposited material. These films have potential for being used in dye sensitised solar cells.