Properties of TiO2 films prepared for use in dye-sensitized solar cells by using the sol-gel method at different catalyst concentrations

TiO2 films were prepared on FTO glass using the sol-gel process for dye-sensitized solar cell applications. The TiO2 sol was prepared by using the hydrolysis/polycondensation. Titanium tetraispropoxide was used as a precursor, and nitric acid (HNO3) was used as a catalyst for the peptization. The crystallinity and the particle size were controlled by adjusting the catalyst concentration and the calcination temperature. The crystal structure and the morphology were measured by using scanning electron microscopy and X-ray diffraction. The TiO2 sol calcinated at low temperatures had an anatase phase, and the amount of the rutile phase with increasing calcination temperature. The properties of the TiO2 sol were adjusted by adjusting the concentration of the catalyst. The prepared TiO2 sol was coated on FTO glass by using a spin-coating method. The transmittance of the TiO2 films was investigated.