Effects of graphene layers in IGZO / graphitelike +Ni/SiO2/Si wafer specimens on electrical and optical properties in tribotests

In the present study, graphite-like +Ni/SiO2/Si wafer specimens were prepared using a co-sputtering system. Then, indium gallium zinc oxide (IGZO) films were deposited onto the graphite-like +Ni/SiO2/Si wafer specimens at deposition powers of 60, 80, and 100 W, respectively. The effects of IGZO deposition power on the specimen’s microstructure and the vacancy defects in the graphite-like +Ni layer are evaluated in terms of the electrical and mechanical properties of the as-prepared specimens. The effects of the graphite-like +Ni film on the electrical resistance of the IGZO film with microcracks is evaluated using a tribotester. The quantity and mean size of microcracks and variations of electrical resistance of the IGZO/graphite-like +Ni/SiO2/Si wafer specimens with time are used to evaluate the role of the graphite-like +Ni layer as an alternate conductor of electric current when the IGZO film is degraded by microcracks. The growth of hillocks in the graphite-like +Ni layer can be enhanced by increasing the IGZO deposition power. These hillocks cause the graphite-like +Ni layer to be convex and have an uneven film thickness, and lead to vacancy defects in the graphite-like film. The O atoms of IGZO were incorporated into graphene in the graphite-like layer as substitutional impurities. The effects of these impurities on the electrical structure with a characteristic of superconductors occur intermittently in the tribotests, resulting in a sharp reduction in the electrical resistance of a specimen. An increase in the intensity ratio, IRO2, related to oxygen vacancies, increases the peak intensities (PIs) of elemental Ga and the Ga-O bond, and decreases that of the Ga-Ga bond. In the IGZO/Glass specimens, a small reduction of the average transmittance is created in the specimens prepared by increasing the deposition power from 60 W to 100 W. The behavior of reflection is exactly opposite to that of transmittance. An increase in deposition power is favorable for the rise of optical band gap (Eg). Increasing the concentration of Zn2p3/2 or Zn2p1/2 increases PIGreen in photoluminescence profiles. Reductions in either In atoms or C-C and C-O bonds increase PIOrange. PIRed and can be increased by either increasing PIGa-Ga or decreasing the values of PIGa2p3/2, PIGa2p1/2, and PIGa-O.