An analysis on structural and optical properties of ZnxCd1−XS thin film deposited by RF magnetron sputtering

The compositional, crystal and microstructural, optical transmission and absorption properties of Zn_xCd_1-xS thin films at low zinc (Zn) content (x=0.2) fabricated by RF co-sputtering using CdS and ZnS were investigated. These ternary compounds were characterized by energy dispersive X-ray analysis (EDX) for composition, X-ray diffraction (XRD) for crystal structure, UV-vis for optical study, forced emission scanning electron microscopy (FESEM) for surface morphology and atomic force microscopy (AFM) for surface topology. XRD patterns of Zn_xCd_1-xS thin films showed the hexagonal structure with a strong reflection peak of (002) plane. From FESEM, the average grain size smaller than 40 nm was observed. Band gap of the films was determined to be 2.6 eV. The average and root mean square roughness of Zn_xCd_1-xS (for x= 0.2) were checked by atomic force microscopy (AFM). The surface of the thin films was found to be smoother, homogenous and densely packed with uniform growth.