Tailoring anatase nanotubes for the photovoltaic device by the anodization process on behalf of microstructural features of titanium thin film

We prepared the anatase nanotubes (NT) and other nanostructured titania as electron accepting/transmitting layers in solar cells, using titanium anodization. Upon gaining control over the anodization, the parameters were held constant in order to observe the role of the deposited layers (by electron beam evaporation and magnetron sputtering) on the NT yield. The structural and microstructural parameters were investigated using FIB-FEG-SEM, XRD, Raman and GIXRD. Differences in the titanium layers play a significant role on the type of titania nanostructures achieved. Only dense homogeneous titanium layer surface, uniform in thickness and without cracks at macroscale, with uniformly seized isotropic nanoparticles, will enable uniform electrochemical etching and thus favourable, reproducible formation of the titania NT, and upon thermal treatment the anatase NT. Transparent conductive oxide (TCO) layers, which are not in direct contact to the NT, can also exhibit influence on the morphology of the titania NT charge transfer layer. In order to reach large uniform areas of nanotubes, which is required for solar cell application, the preparation of titanium layer has to be tailored.