Transparent and p-type conductive NixO:V thin films obtained by reactive DC sputtering at room temperature

Abstract

A non-magnetic alloy consisting of Ni(92%):V(8%) was used to obtain NixO:V thin films by reactive DC magnetron sputtering on unheated glass substrates. The oxygen content and the nickel oxidation state were modified by the oxygen partial pressure (Opp) applied for sputtering, while the film thickness (t) was changed through the deposition time. The structural, optical and electrical properties of the samples have been analyzed by x-ray diffraction, Raman spectroscopy, spectrophotometry and Hall-effect measurements. Visible transmittance and sheet resistance have been used to evaluate the quality of the films as transparent electrodes, which is found maximum for the layers prepared at 24% Opp with t ≤ 100 nm. These samples show maximum p-type conductivity σ = 0.78 S cm−1 and optical absorption α = 1.4 × 105 cm−1 at 0.55 μm wavelength, both independent of the layer thickness.