Highly inorganic titania based sol–gel as directly patternable resist for micro- and nano- structured surfaces

Highly inorganic sol–gel films and patterned surfaces with up to 90% of titania were obtained by hydrolysis and condensation of Titanium(IV) isopropoxide. As a consequence of titania photocatalytic effect, the further treatment of the nanoimprint patterned films by different UV irradiation doses produces highly inorganic micro- and nano-patterns with tunable refractive indexes over a wide range, reaching values over 2.4 at 300 nm. FTIR analysis confirms the degradation of the organic component of the patterns after UV exposure, and TEM analysis shows the presence of crystalline clusters after both thermal treatment and UV exposure. The morphological characterization of the obtained nano-patterned titania structures has been performed by SEM and AFM analysis.