Preparation and characterization of chemical bath deposited nanocrystalline ZnSe thin films using Na3-citrate and hydrazine hydrate: A comparative study

Abstract

In this paper, a comparative study reported on the characteristics of Zinc Selenide (ZnSe) thin films prepared by a chemical bath deposition method using the non-toxic tri-sodium citrate (Na3-citrate) and toxic hydrazine hydrate (HH) as complexing agents. Morphological, structural, chemical, and optical properties were investigated using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–vis spectroscopy. FE-SEM and AFM studies revealed that the ZnSe thin film prepared using Na3-citrate was highly uniform with very low surface roughness (3nm) compared to those prepared using HH. XRD and XPS studies revealed formation of a cubic ZnSe phase and exhibited insignificant Zn3OH formation along with Zn3Se binding energies for both the films. UV–vis study showed that the band gap energies of ZnSe thin films prepared using HH and Na3-citrate were 3.1eV and 2.9eV, respectively. These investigations show that ZnSe thin films could be grown with good optical, structural, chemical, and compositional characteristics without using a toxic HH complexing agent.