Paper presented at MRS Spring Meeting 2011.
“This work presents a critical description of recent cold plasma chemical vapour deposition (PECVD) processes for the growth of oxide thin films and supported nanostructures at low temperatures. Firstly, the growth of oxide thin films is critically addressed by considering parameters such as the angular distribution function of particles or the relative influence of diffusion and shadowing effects in the growth mechanism. Modifications in the thin film deposition processes permit the low temperature preparation of supported oxide nano-fibres and other related nanostructures. Oxide nano-fibres have been prepared on either silver bulk substrates or, in a more controlled way, by using supported metal particle seeds. Examples are reported for the deposition of ZnO and TiO2. Films, hollow nanofibres and other type of supported nanostructures are formed depending on the type of substrates and the deposition conditions. A phenomenological mechanism is proposed which accounts for the nano-fibre growth not by the influence of a catalytic effect, but by the diffusion of the metal and the effect of the plasma electrical field on the growing structures. The importance of the plasma sheath during these nanostructuring processes is highlighted.”