Study of ZnO:V thin films prepared by DC reactive magnetron sputtering at different pressures

Vanadium doped ZnO films with the doping concentration of 0.8% were deposited onto glass substrates at different sputtering pressures by direct current (DC) reactive magnetron sputtering using a zinc target doped with vanadium. The effect of the sputtering pressures (5*10^-3 - 3*10^-2 mbar) on the structural properties of the deposited films have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results of XRD show that all the films have a wurtzite structure and grow mainly with the c-axis orientation. The residual stresses which have been estimated by fitting the XRD results decrease with increasing sputtering pressure. The optical properties of the films were studied by measuring the transmittance. The optical constants (refractive index and extinction coefficient) and the film thickness were obtained by fitting the transmittance. All the results are discussed in relation with the sputtering pressure and the doping of the vanadium.