Exceptionally dense titanium dioxide (TiO2) films were prepared via dip coating from a sol containing poly(hexafluorobutyl methacrylate) as the structure-directing agent. The films were grown on glass, F-doped SnO2, and crystalline silicon (111) faces, either pure or with a thin layer of SiO2. The TiO2 films cover perfectly even rough surfaces, which was ascribed to thixotropic properties of the precursor gel. The films provide antireflection function to crystalline Si wafers for photovoltaic applications. The optical reflectance in visible to near-infrared (NIR) wave lengths region is considerably smaller for Si wafers covered by TiO2/SiO2 film compared with that of SiO2/Si. The dense TiO2 films are amorphous with small amount of anatase and monoclinic TiO2(B). These two phases withstand calcination at 900 °C in films deposited on Si. For comparison, porous TiO2 films were grown by the same dip-coating protocol, but with alternative organic additives, either polymers or ionic liquids.
