The Effect of Doping on the Electrical Conductivity of Vanadium Oxide (V2O5) Films Doped with Nickel Oxide (NiO) Prepared via Pulsed Laser Deposition (PLD).

Abstract

In this research, the focus was on examining thin films of vanadium oxide (abbreviated as V2O5) with different levels of doping using nickel oxide (NiO) (X = 0, 6, 8)%. The films were created through pulsed laser deposition (PLD) method. The thin films were made and subjected to annealing at 450°C for a duration of one hour. The structural properties of the films were examined using the XRD diffraction technique, whereby the films' composition was found to be polycrystalline, featuring an orthorhombic structure. Notably, the films displayed a prominent alignment along the (111) plane, manifesting at an angle measuring approximately 27.889˚. The FE-SEM technology was utilized to explore and evaluate the surface morphology of the thin films. This showed a nanotube-to-spherical shape transformation. Following the implementation of EDX x-ray technique, it was determined that the films comprised the elemental components of vanadium (V), nickel (Ni), and oxygen (O), consistent with the doping ratios. The assessment of the films' optical properties was carried out through the utilization of UV–visible spectrophotometer, demonstrating decreased absorbance and absorption coefficient, as well as an increased energy gap from 2.32 eV to 2.93 eV. The electrical conductivity results indicated a decrease in direct current conductivity (σd.c) with increasing doping ratio, while the activation energy (Ea) increased. Consequently, these films can be utilized in thermoelectric generators.