Synthesis and characterization of titania and vanadia thin films at organic self-assembled monolayers

Functionalized self-assembled monolayers (SAMs) on single-crystal Si wafers have been used as substrates for the deposition of titania and vanadia thin films. The formation of a titanium chelate was used to stabilize an otherwise spontaneously precipitating aqueous titanium solution. Uniform titania films have been synthesized from Ti(O-2)(2+) in aqueous HCl solutions at 80 degrees C on sulfonated SAMs. Vanadium oxide hydrate films, V2O5.0.7 H2O, have been directly formed from aqueous vanadate solutions on NH2-terminated SAMs at 45 degrees C. In the as-deposited films, water molecules were intercalated between the vanadium oxide layers. Subsequent annealing at 350 degrees C in air led to nanocrystalline V2O5.