Structural and optical properties of Zn1−xNixTe thin films prepared by electron beam evaporation technique

Zn1−xNixTe thin films with different composition (x=0.0, 0.05, 0.10, 0.15 and 0.20) were deposited on glass substrate by electron beam evaporation technique followed by its characterization using advanced structural and optical analysis techniques. Structural properties of the prepared thin films were studied by X-ray diffraction (XRD). The XRD patterns revealed that the binary compounds transformed into a ternary compound with cubic structure having preferred orientation along the c-direction with (111) planes. Composition analysis of the films was determined by energy dispersive analysis of X-rays (EDAX) and found to be in agreement with the precursor composition. Optical properties such as extinction coefficient (k) and band gap energy of these films were examined by using a spectroscopic ellipsometer. It was found that the extinction coefficient (k) increased with the addition of Ni content in the alloy. In comparison, the band gap energy was also determined by using transmission spectra and found to be agreed with that of the ellipsometric results. These analyses confirm that the band gap energy decreases with the increase of Ni content in the alloy.