Formation of ZnS nanostructures in SiO2 matrix by RF co-sputtering

Formation of nanorings of ZnS co-sputtered with SiO2 on n-type Si (100) substrates is reported. A subsequent annealing in inert atmosphere at temperature 800 degrees C for 2 hrs was required for development of the crystallinity and the formation of nanorings. The thickness and refractive index of the films estimated by ellipsometry measurements were found to be 180 nm, and 1.59, respectively. X-ray diffraction measurements were performed to study the crystallinity of these nanostructures. It was found that the nanostructures are in wurtzite-hexagonal phase. The sizes of the nanoparticles were estimated to be 54 nm. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were carried out to see the exact shape and size of the nanostructures. Formations of nanorings on the surface were seen in AFM and SEM studies. The outer and inner diameters of the rings were 135 nm, and 65 nm, respectively. Photoluminescence (PL) studies were carried out to see the optical properties of these nanostructures.