Liquid-Phase Patterning and Microstructure of Anatase TiO2 Films on SnO2:F Substrates Using Superhydrophilic Surface

Liquid-phase patterning of crystalline anatase TiO2 thin films on SnO2:F substrates was successfully achieved using a superhydrophilic surface. The superhydrophilic surface on the SnO2:F substrate was micropatterned by UV irradiation (184.9 and 253.7 nm) through a photomask. The substrate was then immersed in an aqueous solution containing ammonium hexafluorotitanate and boric acid at 50 °C. Anatase TiO2 crystallized to form thin films on the superhydrophilic regions selectively because of the acceleration of nucleation and crystal growth. A micropattern of anatase TiO2 was thus fabricated on a SnO2:F substrate in the aqueous solution without any insulating layers, which decrease electrical conductivity between the TiO2 film and SnO2:F substrate. The micropattern was constructed of anatase TiO2 film, in which an assembly of nano TiO2 crystals covered the surface.