The effect of sputtering RF power on structural, optical and electrical properties of CuO and CuO2 thin films

In this paper, the RF power change effect on the structural, optical and electrical properties of CuO thin films prepared by RF reactive magnetron sputtering deposited on glass substrates are studied. At first, the thin films are prepared at 150, 280, 310 and 340W respectively. Then, the films are characterized by XRD, AFM, Uv-visible and four-point probe analysis respectively. The results show that the crystallite size and lattice constant of samples increased from about 20 nm to 59 nm and 4.15 to 4.51 respectively with an increase in RF power from 150 to 340W. The AFM and four-point analysis results show that the samples deposited at 150 and 340W have smooth surfaces and more surface electrical resistance than the samples deposited at 280 and 310W because the dominant phase of samples prepared at 150 and 340W are CuO2 and 280 and 310 are CuO respectively. Also, the results indicate the energy band gap increased from about 2.25 to 2.52eV with an increase in RF power from 150 to 340W and the extinction coefficient of samples prepared at 150W is more than samples prepared at 340W in all of the wavelength.