Effect of substrate type on nanostructured titania sol-gel coatings for sensors applications

Titania coatings were obtained by the sol-gel method, starting from stable and transparent titania sol. Thin titania coatings were deposited onto different substrates: quartz glass, single crystal quartz (1 0 1), single crystal Si(1 0 0) and alumina. Effect of substrate type and heat treatment conditions on important characteristics determining the sensing properties were studied. Nanostructured titania coatings with grain size up to 50 nm and thickness less than 1 μm were obtained on all substrates, but their phase composition depends on substrate type. The slightly orientation of titania coatings as well as the interactions between titania coating and alumina and silicon single crystal were observed.