Properties of the Highly Textured (200) NiO Thin Film Deposited by RF Magnetron Sputtering

Abstract

Nickel oxide (NiO) thin films are a well-known functional p-type material which can be used for many applications such as electrodes, sensors, and electrochromic devices. This work investigated the effect of different deposition power on the crystal structural, electrical, and optical properties of NiO thin films prepared by RF magnetron sputtering at room temperature in a pure argon atmosphere. The structural and optical properties of NiO thin films were examined by using X-ray diffraction and UV–Vis-NIR spectrum, respectively. The thickness and the composition of NiO thin films were analyzed by glow discharge spectrum, and the thickness increased with increasing deposition power. SEM observations showed that the surface particle sizes of NiO thin films increased with increasing deposition power. The crystal structure varied from amorphous phase to (200) orientation as the deposition power increased from 75 to 150 W. The electrical results showed that the 125 W-deposited NiO thin films had the lowest resistivity and the largest mobility and carrier concentration. The absorption edges in the UV region shifted toward lower optical length as deposition power (or thickness) increased. Findings from GDS analysis indicated that the obtained NiO thin films were Ni-rich non-stoichiometric films, which possessed excellent electronic properties.