Tantalum/ Nitrogen and n-type WO3 semiconductor/FTO structures as a cathode for the future of nano devices

Abstract

In the last decades an important number of research papers published on nano chip electrode and cathode electrochromic materials. Tantalum (Ta) with so high melting point can be as a good candidate for the future of nano chip devices. However, its surface has not enough trap centers and/or occupation states, so nitrogen ions exposed on Ta surafce, may solve this problem. For this purpose, in the present work, samples of tantalum with purities of 99.99% (0.58 mm thickness) were implanted by nitrogen ions. The ions' implantation process was performed at 30 keV and also at different doses which were in the range between 1017- 1018 ions/cm2. The electrical, nano structural characteristics, sample surface topography characteristic were investigated on Tantalum nitrides (Ta/N) structures by looking at current–voltage (I–V) curves.In addition to Ta/N, WO3powders as a famous EC metal oxide, a silver metal deposited on fluorine doped tin oxide (FTO)-coated glass andmultilayer structure with using the physical vapor deposition (PVD) apparatus are formed. Some techniques such as uv- visible, Atomic Force Microscopy (AFM) and X Ray Diffraction (XRD) have been used. The obtained results show the formation of hexagonal tantalum nitride (TaN0.43), and more trap centers of sample surface (in comparison to current cathode material of EC device). The electrical resistivity of the tantalum after nitrogen implantation is also found to increase with ion doses.Therefore, Ta/N with more trap centers (rough surface) can be suggested as a good element of the future of EC and nano devices.