Investigations on Physical Properties of Nanostructured Cr doped CdO Thin Films Prepared by DC Reactive Magnetron Sputtering

Abstract

In the present work Cr doped CdO thin films were deposited on mica substrates by varying sputtering powers from 70 to 100 W. X-ray diffraction pattern shows sharp intense peaks at 2θ = 33.04o indicate the preferential (1 1 1) orientation. The crystallite size increases from 35 to 43 nm with the increase of sputtering power from 70 to 100 W. The resistivity of the films decreases from 8.71 x 10-4 to 1.93 x 10-4 Ω.cm with the increase of sputtering power from 70 to 100 W. The decrease in resistivity with increase sputtering power can be attributed to the high dense surface of Cr doped CdO thin films and reduced grain boundary scattering. The carrier concentration of the films increased from 1.36 x 1021 to 1.60 x 1021 cm-3 with the increase of sputtering power from 70 to 100 W. The carrier mobility of the films increases from 68 to 82 cm2V-1s-1 with the increase of sputtering power. The best figure of merit of value 1.39 x 10-2 Ω-1 with low resistivity of 1.93 x 10-4 Ω.cm, high optical transmittance of 75% and low sheet resistance value of 5.5 Ω/sq is obtained for the thin film deposited at sputtering power of 100 W.