We investigated how mixtures of Ar and 02 or N2 gases affect the structural, electrical and optical properties of RF-magnetron-sputtered NiO films. It is shown that the addition of 02 gas to Ar ambient (namely, Ar:o2=2:1 to 1:2) slightly reduces the (2 0 0) texturing of the NiO films. The introduction of N2 gas (from 0 to 2 seem) to Ar:02(2:1) mixture enhances the (2 0 0) texturing, while the addition of N2 gas (from 0 to 2 seem) to Ar ambient slightly weakens the (1 1 1) texturing. The deposition rate is reduced from 6.1 to 1.5 nm/min when o2 gas is added to Ar ambient. The addition of N2 gas to the Ar:o2(2:1) mixture slightly increases the deposition rate from 1.8 to 2.6 nm/min, whereas adding N2 gas to Ar only ambient somewhat reduces the rate from 6.1 to 4.4 nm/min. The carrier concentration of the films is increased and the mobility is decreased as the o2 flow rate in the Ar:o2mixture is increased. The addition of N2 gas to the Ar:o2 (2:1) mixture increases the resistivity of the films, while adding N2 gas to Ar ambient decreases the resistivity. The transmittance and optical bandgap of the films are reduced (from 58.4 to 45.5% at 550 nm and from 3.5 to 3.3 eV, respectively) with increasing 02 flow to Ar ambient When N2 gas is added to the Ar:o2 (2:1) mixture, the transmittance in the visible wavelength range increases from 58.4 to 71.3% and the optical bandgap increases from 3.5 to 3.6 eV. However, adding N2 gas to the Ar only ambient results in decrease in the transmittance in the visible wavelength region (from 69.3 to 56%) and the optical bandgap (from 3.7 to 3.5 eV).
Bibliographical noteFunding Information:
This work was supported by the World Class University program through the National Research Foundation of Korea funded by MEST ( R33-2008-000–10025-0 ).
- Magnetron sputtering
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering