Fine patterned TiO2:Nb transparent conducting films prepared by a photochemical etching technique

Herein, microfabrication of a novel Nb-doped titanium dioxide (TNO) transparent conductive film is proposed using a photosensitive sol-gel method. The method employs a chemical modifier to coordinate Ti 4+ in sol, followed by gel film preparation. The obtained Ti-coordinated chelate has a characteristic absorption peak at ca. 360 nm, which disappears after sufficient exposure to UV radiation. This feature is much similar to that of photoresist. Upon irradiated by UV light through a mask, the film can be dissolved in ethanol in order to obtain a fine-patterned surface. Finally, after annealing treatment at 450 °C Nb 5+ -doped TiO 2 fine-patterned transparent conducting film is obtained. This photochemical lithographic technique integrates photochemical etching and filming process into one step, whilst effectively avoiding damage caused by conventional lithographic techniques (such as dry etching and wet etching) on the photoelectric properties of TNO film. Our methodology eliminates the need for photoresist, creating a simple process that is expected to be performed on large film area.