Sol-gel surface functionalisation by cold-processing for optical sensor applications

The structure and physical properties of a thin titania sol-gel layer, prepared on silicon and silica surfaces by cold processing and spin-coating techniques, were examined. A series of spectroscopic (FTIR, UV-VIS spectroscopy and ellipsometry) and microscopic (light microscopy, SEM and EDS) techniques were used to examine the chemical and physical uniformities of the sol-gel layers. Conditions were established to generate uniform layers reproducibly. The high refractive index, selective binding to organic functional groups and the light and gas transmission properties of the titania layers can be successfully made use of for new optical sensor applications.