Effect of Ni incorporation on structural, optical and magnetic properties of electron beam evaporated ZnS thin films

Nickel (Ni) incorporated zinc sulfide (Zn1-xNixS) thin films at different Ni concentrations (x = 0.00, 0.02, 0.05, 0.08 and 0.10) were prepared by EB technique. The effect of Ni concentration on structural, morphological, optical and magnetic properties were studied using different characterization methods including X-ray diffraction, atomic force microscopy (AFM), scanning electron microscopy, energy dispersive analysis of X-ray (EDX), UV-Vis-NIR spectroscopy, photoluminescence (PL) spectroscopy and a vibrating sample magnetometer.The Ni-doped ZnS thin films exhibited cubic structure with preferred orientation along (1 1 1) orientation. The average crystallite size was about 20 nm. The AFM images indicated dense and homogeneous particles on the surface of the films with good and compact grain connectivity. The EDX spectra showed the presence of host and dopant elements in prepared thin films. The thin films showed high optical transmittance in the visible region and increased from 80 to 88% with increasing Ni concentration from x = 0.00 to x = 0.10. The optical band gap decreased from 3.46 to 3.25 eV with increasing Ni concentration. A broad emission peak at 463 nm was observed from the PL spectra. The undoped and Ni-doped ZnS thin films exhibited weak ferromagnetism at room temperature.