Novel reduced toxic route synthesis and characterization of chemical bath deposited ZnSe thin films

Abstract

The synthesis of chemical bath deposited zinc selenide (ZnSe) thin films using a mixture of non-toxic complexing agent tri-sodium citrate (Na-3-citrate) and hydrazine hydrate (HH) and their physico-chemical properties are reported. Various amounts of complexing agent Na-3-citrate and HH solutions were prepared and used, listed as A, B, C, D, E and F. The effects of Na-3-citrate and HH concentration on the morphological, structural, compositional, chemical and optical properties of ZnSe thin films were investigated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Energy dispersive X-ray spectroscopy (EDS) and ultraviolet visible spectroscopy, respectively. FE-SEM and AFM studies revealed that the uniformity of the ZnSe thin films decreased whilst RMS values increased for the films deposited from solutions A to F. XRD studies showed that the ZnSe thin films had no well resolved peaks showing an amorphous nature while peaks from (111), (220) and (311) planes corresponding to the ZnSe cubic phase were observed for the film deposited with solution A. EDS analysis revealed that the presence of Zn atom in the ZnSe thin films increased for the films deposited from solutions A to F. UV-visible study showed that the band gap energy increased from 2.65 to 3.55 eV for the ZnSe thin films deposited from solutions A to F.