Cobalt oxide thin films were deposited on glass and silicon substrates using reactive cathodic radio-frequency sputtering from a pure cobalt target in oxygen/argon gas mixtures with different percentages of oxygen (10, 30, 40 and 50 %). The X-ray diffractograms showed that deposited thin films crystallized in a cubic Co 3 O 4 phase. The crystallite size was found to vary with the oxygen pressure, reaching a maximum using 40 % of O 2 . Scanning electron microscopy (SEM), AFM, energy dispersive X-ray spectroscopy and Raman scattering analyses confirmed the formation of Co 3 O 4 films with nano-sized particles. In addition, it is found that the optical band gap of the films increased with increasing oxygen pressure in the sputtering atmosphere. Finally, the electrical resistivity of the sputtered thin films was shown to increase with oxygen-percentage.

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Zinc sulphide (ZnS) thin films have grown on glass and Si substrates by reactive cathodic radio frequency (RF) sputtering. The RF power was varied in the range of 100 to 250 W, while the deposition time is set at 75 min. The optical, structural, and morphological properties of these thin films have been studied. The optical properties (mainly thickness, refractive index, absorption coefficient, and optical band gap) were investigated by optical transmittance measurements in the wavelength range of ultraviolet-visible-near infrared spectroscopy and spectroscopy infrared with Fourier transform. Fourier (FT-IR) and XRD analysis indicated that all sputtering ZnS films had a single-phase with a preferred orientation along the (111) plane of the zinc sphalerite phase (ZB). The crystallite size ranged from 11.5 to 48.5 nm with RF power getting a maximum of 200 W. UV–visible measurements exhibited that the ZnS film had more than 80% transmission in the visible wavelength region. In addition, it has been observed that the band gap energy of ZnS films is decreased slightly from 3.52 to 3.29 eV, and as the RF power is increased, the film thickness increases with the speed of deposit growth. Scanning electron microscopy observations revealed the types of smooth-surfaced films. The measurements (FT-IR) revealed at wave number 1118 and 465.02 cm−1 absorption bands corresponding to the symmetrical and asymmetric vibration of the Zn–S stretching mode. X-ray reflectometry measurements of ZnS films have shown that the density of the films is (3.9 g/cm3) close to that of solid ZnS.

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