Femtosecond pulsed laser deposition of nanostructured TiO2 films in atmosphere

Nanostructured TiO2 films were grown on a monocrystalline silicon substrate by a femtosecond pulsed laser ablating a Ti target in atmosphere without a vacuum chamber. FESEM and XPS results showed that the TiO2 nanomaterials prepared by this method have a fluffy structure composed of nanoparticles which have a particle size in the range of 1-100 nm, resulting in a high specific surface area of 88.6 m2/g. XRD results showed that the deposited films have a composited phase which is composed of anatase, rutile and amorphous TiO2. The reason for the formation of this nanostructure is mainly because of the collision with gas molecules and oxidation reaction of Ti ions. The method may be used to prepare other metal oxide nanostructured films.