Photo-induced hybrid nanopatterning of titanium dioxidevia direct imprint lithography

Abstract

A novel ultraviolet (UV)-assisted imprinting procedure that employs photosensitive titanium(IV) di-n-butoxide bis(2-ethylhexanoate) is presented for the fabrication of well-ordered titanium dioxide (TiO₂) nanostructures at room temperature. The main novelty of this technique is the use of the photosensitive titanium organic compound, rather than a commonly used UV-curable resin, for direct UV-assisted nanoimprint lithography. Fourier transform infrared and X-ray photoelectron spectroscopy studies suggest that exposure to UV light resulted in the gradual removal of organic groups from films prepared from titanium(IV) di-n-butoxide bis(2-ethylhexanoate) photochemically and successively converted the films to TiO₂ at room temperature. This approach allows direct fabrication of TiO₂ nanopatterns with lines down to 35 nm in width, hole arrays of 265 nm in diameter, and three-dimensional TiO₂ hybrid micro/nano-patterns without observable defects for use in applications where ordered surface nanostructures are required, such as photovoltaics, photonics, and optical waveguides.