ELECTROPHORETIC DEPOSITION OF BiVO₄ LAYERS ON FTO SUBSTRATES FOR PHOTO ELECTRO-CHEMICAL CELLS

Abstract

In this paper the deposition of BiVO₄ onto fluorine doped tin oxide (FTO) substrates by electrophoretic deposi-tion (EPD) is presented. The BiVO₄ powder was fabricated by a mixed oxide route and added by a solvent and dispersant to achieve the suspension for EPD. The particle size, sintering parameters, and crystal structure of the powder were characterized by laser light diffraction, dilatometer, and X-ray diffraction, respectively. EPD was performed at deposition voltages between 12.5 V and 100 V resulting in layer thicknesses in the range of 0.5 μm and 2.8 μm after sintering. The current density of the layers was determined for frontside and backside illumination of the FTO substrates at different wavelengths in the range between 400 nm and 600 nm. The band gap was determined at 515 nm, which corresponds to 2.5 eV. The maximum external quantum efficiency (EQE) was measured at 440 nm and backside illumination.

Keywords

• Solar water splitting; Photo electro-chemical (PEC) cells; BiVO4; External quantum effi-ciency (EQE)