Low resistivity of Ni-Al co-doped ZnO thin films deposited by DC magnetron sputtering at low sputtering power

Abstract

Ni-Al co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates by DC magnetron sputtering in Ar using a single ceramic, spark-plasma-sintered target with 2 wt% Al and 5 wt% Ni. The effects of the sputtering power and gas pressure on the NiAl:ZnO films were studied. The structural, electrical, and optical properties of the films were characterized by X-ray diffraction, field emission scanning electron microscopy, Hall effect measurements and UV-vis transmission spectroscopy. As the sputtering power and gas pressure increased, the crystallinity, electrical properties and optical band gap of the films were improved. The NiAl:ZnO film deposited at 40W at 6.0 mTorr had the strongest (002) XRD peak and the lowest resistivity of approximately 2.19 10(-3) Omega cm with an optical transmittance of 90%. (C) 2013 Elsevier B.V. All rights reserved.