Composition and Conductivity-type Analysis of Spray Pyrolysed ZnS Thin Films using Photoluminescence

Photoluminescence (PL) technique has been employed to successfully determine the composition and conductivity type of spray pyrolysed ZnS thin films. Aiming to improve the optoelectronic properties, ZnS thin films were deposited using different precursors for zinc. Variation in Zn:S ratios were also tried along with a variation in precursor which naturally brings compositional variations which in turn reflects in the PL spectrum. From the XRD patterns a modification in crystal structure was observed in the case of acetate based ZnS films. This modification reflected as a shift in the PL peak position. Acetate based films exhibited conductivity type variation: films with low sulphur content were n-type and those which were rich in sulphur were p-type.